####018006436#### FXUS62 KCHS 030739 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 339 AM EDT Fri May 3 2024 .SYNOPSIS... Atlantic high pressure will remain across the Southeast through much of next week. && .NEAR TERM /THROUGH TONIGHT/... This morning: Satellite imagery, surface observations, and webcams showing some fog and stratus developing across parts of the area. This is a little later than it was yesterday morning, and also there is less coverage so far. However, there is a strong inversion just off the surface, and with dew point depressions down near or at zero, the fog will expand in coverage. Since we're still not certain that there will be enough dense fog, no Dense Fog Advisory has been issued. The fog (whether it's dense or not) will dissipate by 9-10 am since the depth of the fog is somewhat shallow. Today: The mid level ridging of recent days will shift off the coast of the Southeast, while Atlantic high pressure is the main feature at the surface. The synoptic flow is southeasterly through the day, resulting in a sea breeze dominant regime. After fog dissipates, scattered to broken cumulus will prevail, while varying amounts of cirrus clouds pass through. There will certainly be sufficient insolation, and temperatures will be very similar to yesterday. We didn't go quite as warm as the 1000-850 mb thickness progs, but with a blend of the MOS and NBM, we arrive at highs in the mid and upper 80s. Coastal sections will be 5-10F cooler. A subtle level level impulse will approach from the west- southwest late in the day, and this will cause isolated to scattered convection upstream from our Georgia counties to approach. There will be some interaction of this activity with the inland moving sea breeze after 3 or 4 pm, where we show slight chance PoPs close to and west of the US-301 corridor (Allendale to Tattnall County). There is little buoyancy, plus limited MLCAPE and shear, so no strong or severe storm will occur. Tonight: A better looking short wave trough moves through the Tennessee Valley and northern Gulf coast. This along with any outflow boundaries from prior convection in and near the area, will allow for isolated or scattered showers and a few t-storms to occur. This is mainly far inland sections. There will be at least some form of fog again after midnight given the southeast and south flow in the boundary layer. However, there is likely too much mid and high level clouds from the nearby convection for dense fog to occur. We currently have mention of the "patchy" fog qualifier, and we will monitor for any dense fog potential. Low temperatures will be several degrees above climo. && .SHORT TERM /SATURDAY THROUGH MONDAY/... A mid-level ridge axis will push off the Southeast coast Saturday with passing waves of shortwave energy across the region through the short term forecast period. High pressure will remain the primary feature at the surface. Convection should be a bit more active over the weekend and into Monday with the presence of deeper moisture as PWATs increase to 1.5+ inches. Coverage of showers/thunderstorms will be highest in the daytime when instability is maximized, but with some upper forcing in play activity could linger into the overnight period. The greatest chances are focused away from the immediate coast owing to a progressive sea breeze. High temperatures will generally peak in the low to mid 80s over the weekend, warming into the mid to upper 80s Monday. Overnight lows are only expected to drop to the mid to upper 60s, with locations right along the beaches and Downtown Charleston near 70 degrees. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... Atlantic high pressure will persist through the middle of next week. Chances for showers/thunderstorms are limited Tuesday as weak forcing/remnant shortwave energy passes offshore the Mid Atlantic coast. Beyond Tuesday, rainfall chances are little to none as a ridge rebuilds overhead. This will allow max temperatures to rise into the low/mid 90s by mid next week, possibly approaching record levels by Wednesday/Thursday. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... KCHS/KJZI/KSAV: Fog and stratus are still expected to occur during the pre-dawn through mid morning, and dense fog and conditions down near or below airfield minimums are possible for several hours. Expect there to be updates, but for now we have the worst conditions at all terminals between 09Z and 13Z. It's possible that with a southeast synoptic flow, the fog and stratus might be mainly inland from KJZI. VFR will return around 1300-1330Z, and continue into tonight. There are no concerns for SHRA or TSRA at any the terminals with the 06Z TAFs. Extended Aviation Outlook: Scattered showers and thunderstorms are possible through Monday. && .MARINE... Today: High pressure from the Atlantic will be the main feature, and even with sea breeze influences this afternoon, SE winds will be no more than about 10 kt. Seas will be only around 2 feet. Even though it is light, the onshore flow will keep any land based fog off the Atlantic. The exceptions will be Charleston Harbor (especially the northern part of the harbor near the North Charleston Port) and the Port of Savannah, where some of the nearby fog from over the land could drift into those areas early this morning. At this time no Dense Fog Advisory is planned. Tonight: Weak high pressure continues across the maritime community. Once again the SE winds are no more than about 10 kt, with seas just 2 feet. Maybe some fog could impact Charleston Harbor and the Port of Savannah, as it tries to expand in from nearby land sections. Saturday through Wednesday: Atlantic high pressure will maintain benign conditions over the local waters. Southerly winds in the morning will back out of the southeast during the afternoon and evening hours nearly each day as the sea breeze develops. Winds will average 10-15 kt with seas 2-3 ft. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE... ####018007100#### FXUS61 KGYX 030741 AFDGYX Area Forecast Discussion National Weather Service Gray ME 341 AM EDT Fri May 3 2024 .SYNOPSIS... High pressure near the coast will provide a drier and quieter couple of days between today and Saturday, however it will also contribute to a growing onshore flow this weekend. Thickening clouds, cooler temperatures and rain showers are expected by Sunday... with clearing likely not coming until Monday. Warmer and sunnier conditions are expected Monday and Tuesday, then more unsettled weather returns around the middle of next week. && .NEAR TERM /TODAY/... Impacts: *No significant weather impacts expected Clouds continue to roll over the ridge this morning, however a clear slot did develop overnight allowing fog to form and some areas to quickly drop a few degrees. Now, as the mid-level cloud deck fills back in, fog is dissipating and temperatures are plateauing. As the ridge moves overhead and surface high pressure builds in today, skies will gradually clear and with BUFKIT soundings showing a return to good mixing, high temperatures should climb into the 60s areawide. The only exception would be the coast where the seabreeze will keep temperatures in the 50s. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... Impacts: * No significant weather impacts expected Skies will remain partly cloudy overnight which will keep us from having a widespread radiational cooling night, but with continued light winds there is opportunity for patchy dense fog and some quick temperature drops in areas that can find some clear skies. Generally low temperatures look to be in the low to mid 40s across the area with some upper 30s north of the mountains. The 500mb ridge axis inches ever closer, but models suggest the offshore upper low keeps the pattern pretty blocked up for Saturday. Expect clouds to increase through the day as we see warm moist advection from the southwest. BUFKIT profiles suggest another well mixed day so the clouds shouldn't keep us from once again climbing into the 60s across most of the area, with the coast once again topping out in the 50s due to the seabreeze. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... An upper level ridge this weekend is replaced by an upper level trough to start next week, with rainy and cool weather eventually yielding to a drier, warmer couple of days to start the upcoming work week. Another frontal system approaches with increasing rain chances around the middle or latter part of next week. All in all neither of these systems look to be particularly impactful in terms of a significant hydrological or convective threat, and overall this will be a stretch of typical Spring weather with an active but ultimately benign pattern. Starting Saturday night... high pressure along the eastern periphery of Maritime Canada and a cold front approaching from the Great Lakes continue to produce onshore flow into New England. Clouds will fill in through the low and mid-levels especially south and east of the mountains into Sunday, with potential for fog and perhaps some patchy drizzle development during the morning as an upper level ridge rolls overhead. Shower chances meanwhile will increase from the west through the day Sunday amid pressure and height falls... culminating in a likely period of rain as a pre-frontal trough crosses Sunday afternoon and/or evening. Although the cold front itself won't cross until Monday, the moisture axis will be attached to the pre-frontal feature... with generally 0.2-0.4" of rainfall. Temperatures meanwhile won't warm too much on Sunday thanks to warm advection atop the cool marine layer, with highs generally in the 50s... coolest in the 40s along the coast. In terms of sensible weather conditions, a question will be the progression of the cold front itself as its passage will bring fresh westerly flow. There will be a gap between the bulk of the rain/deep moisture exiting late Sunday and the low-level humidity being flushed out with the cold front on Monday. Thus, would expect the overnight to remain a bit damp with fog and drizzle potential. Current model consensus mixes this out through the mid- or late- morning hours, with a mix of sun and clouds and far warmer temperatures on Monday. Highs are forecast to be in the 60s and 70s, coolest in the north where upsloping clouds and a few showers are expected to remain. Light winds and the warm temperatures should allow a sea breeze to develop. Upper level low pressure settles across Maritime Canada and a ridge axis nudges east toward New England. Resultant northwest flow reinforces the drier airmass with what looks to be a great day on Tuesday... featuring temperatures again warming into the 60s and 70s, light flow, an afternoon seabreeze, and what will likely be partly or mostly sunny skies. Forecasting the upper air pattern becomes a bit fuzzy toward the middle of next week with an increasingly blocked pattern and a general trend toward more zonal flow over the Northeast with the jet nearby or overhead. This introduces the potential for shortwaves moving through the jet to bring showers across the area... and indeed have PoP and cooler temperatures on the increase again toward the middle of the week. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... Short Term...A mixed bag of LIFR/IFR/MVFR ceilings early this morning will gradually improve to VFR as the day goes on. We will most likely return to areas of LIFR in fog tonight, but quickly improve back to VFR Saturday. Winds will be light and variable across the area. Long Term...Periods of IFR are likely Sat night through Mon morning with light SE flow turning N thru Sun, then SW or W Mon. Prolonged and more significant restrictions are most likely along the coast with low CIGs and some lowered VSBY... with all terminals expected to have at least a few hours of restrictions with -RA crossing the area on Sunday. Conditions trend back to VFR Mon, except potentially MVFR CIGs in the north... then all VFR on Tue. && .MARINE... Short Term...Conditions hazardous to small craft are not expected. High pressure building over the waters will keep winds light and variable through tonight, with an afternoon seabreeze developing. For Saturday, winds will be blowing onshore at around 8-10 kts. Long Term...SE flow across the waters Sat night increases to around 10-15 kts sustained by late Sun...with potential for fog and rain thru Mon morning. A front crossing the waters brings clearer conditions late Mon into Tue, with light winds generally out of the west (NW or SW) into midweek. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR/SHORT TERM...Baron LONG TERM...Casey ####018011231#### FXUS61 KAKQ 030741 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 341 AM EDT Fri May 3 2024 .SYNOPSIS... A backdoor cold front pushes into the Maryland eastern shore late tonight, then inland across the remainder of the area on Friday, leading to much cooler conditions at the coast. Rain chances return Friday evening through Sunday as a series of disturbances impact the region. Summerlike conditions return to the area by the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... As of 335 AM EDT Friday... Early morning sfc analysis shows high pressure still anchored over the Atlantic off the coast of the SE CONUS. Meanwhile, a backdoor cold front is located just to the north of the local area. Aloft, an amplified ridge extends into Canada with its axis just to the west of the FA. Temps this morning will be fairly mild with temps remaining in the 60s for most places (upper 50s in the NW). The backdoor front will sag south today, creating non-diurnal temps that will have a sharp gradient from NE to SW. For most locations W of the bay, expect temps to quickly warm into the low 80s by mid- morning, while the Northern Neck and the Eastern Shore remain cool in the upper 50s-low 60s. Through the afternoon, cooler temps will spread inland. Mid-afternoon temps will be in the 50s on the Eastern Shore, 60s across the peninsulas and the SE coast, while the central and southern piedmont will be in the mid-upper 80s. Clouds will increase through the day, becoming broken to overcast by the afternoon. Winds turn to the NE behind the front and become breezy, gusting to 20-25mph. There is a slight chance for showers/thunderstorms in the piedmont this afternoon, but CAMs indicate isolated coverage. Showers likely increase in coverage late in the evening and overnight, but still look limited to the piedmont and still scattered (40-50% PoPs). Lows tonight/tomorrow morning will be a bit cooler than this morning, dropping into the 50s. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... As of 905 PM EDT Thursday... Key Messages: - Increasing clouds from NE to SW Friday into Friday night as a cold front drops across the region. - Rain chances increase mainly west of the bay tomorrow afternoon into tomorrow evening. Lighter, intermittent rainfall possible along the coast tomorrow night and into Saturday. The backdoor front will continue to move SW across the region on Friday. Models have good timing on the front, reaching the VA eastern shore and SE VA Friday morning, the RIC metro around lunch time, then to the southern Piedmont of VA by late afternoon. Latest CAMs show some pop up showers for areas mainly west of I-95 as the front moves SW. Have therefore included slight chance PoPs for the afternoon in that same general region. Could not completely rule out thunder as the HREF mean SBCAPE shows 500-1000 J/KG. There will be quite a gradient of temperatures across the area, with Ocean City likely staying in the 50s through the day, while areas in the southern Virginia Piedmont will reach upper 80s for highs. The temperature will likely remain steady or even fall slightly once the front passes your location tomorrow. Improved moisture return sets up for Friday night and continues into Saturday. Best moisture stays mainly over the Piedmont, and will also be helped by overrunning over top the low level wedge. The better moisture and lift moves in on Saturday as the 850mb winds increase and have kept likely PoPs over the Piedmont, tapering to low chance at the coast. Even at the coast though, it will not be terribly pleasant in the morning with onshore flow, low clouds and the potential for drizzle into Saturday morning. Have generally undercut the NBM highs for Saturday, especially across the far NW. Highs will range from the mid 60s (or possibly even lower) in the NW piedmont counties, to lower 80s across the far south where some afternoon sunshine is possible. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 905 PM EDT Thursday... Key Messages... - Additional scattered showers and storms on Sunday and Monday. - A more summer-like pattern with warmer days and chances for late afternoon and evening showers and storms appears to be on the way for the middle of next week. The backdoor front will attempt to move back north on Sunday as the Ohio valley system approaches from the west. Showers may be more widespread on Sunday due to a weak disturbance aloft lowering heights across the region. Best moisture and still expected along/west of I-95. As such, have continued with likely/categorical PoPs over the west on Sunday, tapering to chance PoPs at the coast. Highs expected to be warmer than Saturday in the mid 70s to lower 80s, warmest SE VA/NC NC. By Monday, the warm front will be well north of the area. However, the system over the Ohio Valley will be moving through during the day. Expect another round of showers/storms mainly during Monday afternoon into Monday evening as a stronger upper disturbance moves through in the W-NW flow aloft. Slightly more instability on Monday vs Sunday so more thunderstorms are expected. We get into an almost summertime pattern by Tuesday as the ridge aloft builds overhead with afternoon/evening showers and thunderstorms each day being triggered by the lee side trough. The GFS and ECMWF both suggest the ridge breaks down slightly by Wed/Thu with stronger 500mb flow of up to 50 kt by Wed afternoon. Along with this, those models suggest weak short waves (likely of mesoscale origin from convection over the Ohio Valley and central plains) moving through the area. Although we are talking about days 6 and 7, the relatively strong upper flow combined with relative steep mid level lapse rates of up to 7 C/km would suggest the possibility of severe weather. In fact, the CSU Machine Learning Probabilities suggest a slight risk for severe weather on Wednesday and again on Thursday. We have plenty of time to monitor this, but the area may become a little more active by the end of next week. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... As of 150 AM Friday... VFR conditions with light winds to begin the 06z TAF period, with VFR conditions to prevail through the rest of the night. A backdoor cold front dives southwest across the Maryland Eastern Shore towards sunrise this morning, allowing winds to turn NE, with MVFR conditions on the eastern shore tomorrow, especially east of KSBY to KOXB. The front will continue to slowly move SW today, perhaps reaching the other terminals by 18-20z. Some scattered showers and perhaps even a thunderstorm will be possible at KRIC and points west tomorrow afternoon into tomorrow evening. Flight restrictions (primarily low CIGs) are expected to spread to the other terminals starting late this evening and last into Saturday. Outlook...Sub-VFR conditions expected at times through through the weekend and even into early next week due to an unsettled weather pattern through Monday. A series of systems will cross the region, with chances for rain/storms each day. A warmer, more summerlike pattern returns by Tuesday with chances for storms each afternoon/evening. && .MARINE... As of 300 AM EDT Friday... Key Messages: - Small craft advisories are in effect for the Chesapeake Bay and lower James River, and for the Ocean N of Parramore Island for today behind a backdoor cold front. -Winds diminish a bit late tonight/Sat morning, but additional Small Craft Advisories may bee needed by lat Saturday/Saturday night. Still rather quiet across the waters early this morning with SSW winds of 10-15 kt or less and seas 2-3 ft N/1-2 ft S, with waves in the Bay and rivers 1-2 ft (or less). The wind has shifted to the NNE at buoy 44009 and into the Ocean zone from the MD/DE border south towards Chincoteague. There may be a few hrs worth of marine fog toward sunrise in these northern Atlantic coastal waters before the winds increase, but do not anticipate this being enough for a Marine Dense Fog. Otherwise, E/NE winds increase abruptly later this morning as cool/dry advection gets going behind the front with pressure rises on the order of 4-5mb/6 hr. E-NE winds increase to 15-20 kt with gusts to around 25 kt, but will likely over- perform at least across the northern coastal waters so have added the Ocean zones N of Parramore to a Small Craft Advisory through 4pm this aftn (with winds ~20kt gusting to 25 to near 30 kt), and seas of 4-5 ft. The highest confidence in meeting small craft criteria is in the southern bay/lower James, but the entirety of the bay should at least see marginal SCA conditions. In the Bay/James, SCA headlines remain in effect from later this morning/aftn through 1 AM Sat morning. On the ocean S of Parramore, wind gusts and wave heights on average should stay below 25 kt with seas building to ~4ft. Should note that onshore flow conditions tend to elevate seas a bit higher than guidance, so will monitor the trends later this morning As of now, will keep these zones out of any headlines. Easterly winds subside some by Sat morning, but will remain around ~15 kt. Wind speeds tick up again later Sat aftn/Sat night while shifting to the SE. This brings another chance at SCA conditions, again mainly over the Bay. Seas remain 3-4 ft with waves 2-3 ft in the bay/rivers/sound. The front lifts back N on Sunday, shifting winds to the S. SSW winds return for Monday through the middle of next week (but likely remain sub-SCA). && .TIDES/COASTAL FLOODING... As of 130 AM EDT Friday... Tidal departures increase later today in response to the winds turning onshore from the E or ENE. May consider a statement for the lower Bay/lower James and for the upper Bay across the northern Neck and perhaps Dorchester MD for the tide cycle this evening/tonight depending on how the water levels respond. Additional tidal flooding, mainly to minor flood thresholds appears likely by later Sat through Sunday across the upper Bay as winds become more SE to S. Moderate levels are not expected (except perhaps locally at Bishops Head), so no Coastal Flood Watches are anticipated. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 10 AM this morning to 1 AM EDT Saturday for ANZ630-631. Small Craft Advisory from 1 PM this afternoon to 1 AM EDT Saturday for ANZ632-634-638. Small Craft Advisory from 7 AM this morning to 4 PM EDT this afternoon for ANZ650-652. && $$ SYNOPSIS...MRD NEAR TERM...AM SHORT TERM...MRD LONG TERM...MRD AVIATION...AM/MAM MARINE...LKB/SW TIDES/COASTAL FLOODING... ####018005950#### FXUS64 KMRX 030741 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 341 AM EDT Fri May 3 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (Today and tonight) Issued at 330 AM EDT Fri May 3 2024 Key Messages: 1. Increasing chances of showers and storms this morning through the evening, with a potential lull in activity overnight. 2. While severe weather is not expected, a few instances of small hail, wind gusts up to 40 mph, and locally heavy downpours are possible this afternoon. Discussion: Upper level disturbances will bring increasing chances of showers and storms to the forecast area today. Regional mosaic radar already depicts a rain shield moving into western Kentucky, central Tennessee, and eastern Mississippi this morning. Precipitation chances will gradually increase across our forecast area through the morning hours, with just general rain showers as the predominant weather type. As we transition into the afternoon hours, hi-resolution models suggest development of MLCAPE in the 300-800 J/kg range, which will lead to increasing chances of thunder. A weak shear profile and mid level lapse rates struggling to reach 6C/km should keep any storms from reaching severe levels, although, any stronger storm could lead to locally gusty winds up to 40mph and pea-size hail. PWAT values will generally approach near 1.4 inches. This is around the 90th percentile based on sounding climatology out of BNA. As such, we cannot totally rule out some isolated flooding concerns with any slow moving or training convection this afternoon. Thankfully, below normal rainfall over the last month has allowed for 1 hr FFGs of 1.8-2.3" across the forecast area, really minimizing this threat. A marginal risk for excessive rainfall covers areas generally along and west of I-75 - where the better chance for relatively more effective convection exists. Temperatures will typically be near normal. Ensemble guidance suggest we may see a window of little to no activity during the late evening/overnight hours. && .LONG TERM... (Saturday through Thursday) Issued at 330 AM EDT Fri May 3 2024 Key Messages: 1. An unsettled pattern is expected through the extended period with daily scattered to numerous showers and storms. More organized convection is possible by Wednesday/Thursday of next week. 2. Temperatures will be generally above normal, especially next week. Saturday through Monday At the start of the period, a fairly weak upper-level flow pattern will be in place with a shortwave moving in from the west. With broad moisture and surface heating, Saturday will consist of scattered to numerous convection throughout the day. Based on the weak flow, the convection will be thermodynamically-driven as very minimal shear will be present. Overall, instability will be fairly typical of the summer, i.e. near 1,000 J/kg of MLCAPE. PWATs will also be 1.4 inches or higher, which is around the 90th percentile for this time of year. With these conditions, some stronger storms with gusty downburst winds are possible, in addition to locally heavy rainfall rates. Thankfully, fairly dry conditions, including low-end drought, will keep any flooding concerns very localized. Heading towards Sunday, gradual height rises are expected with embedded shortwave energy and similar thermodynamic conditions. This will lead to slightly warmer temperatures than on Saturday with additional showers and storms expected. A closed upper low will also be noted to our west and will approach towards Monday. This may lead to slightly better coverage than on Sunday, but the overall impact will be the same. Tuesday through Thursday The unsettled pattern will continue into the middle of the week with continued embedded shortwave, broad moisture, and surface heating on Tuesday. By Wednesday to Thursday, however, a more dynamic pattern is anticipated with the upper jet (in excess of 100 kts) dipping further south. Upper-level divergence will help to strengthen the 850mb, possibly to in excess of 40 kts. A surface front will also slowly drift southward. While discrepancies still exist, these indications suggest an environment with potentially better thermodynamics and deep-layer shear sufficient for more organized convection than in the earlier part of the extended period. At this time, low probability HWO wording will be kept to encompass the multiple rounds of convection and potential locally heavy rainfall. However, the Wednesday to Thursday timeframe will be something to watch for more organized and/or robust convection. && .AVIATION... (06Z TAFS) Issued at 139 AM EDT Fri May 3 2024 VFR conditions will be predominant through the TAF cycle, with mid to low level BKN/OVC clouds increasing through the morning into the afternoon. Continue to expect increasing rain chances near CHA and TYS this morning, with chances for a few thunderstorms by the afternoon. Rain chances increase late morning to mid-day at TRI, and have kept thunder omitted. Recent hi-resolution guidance suggest by late Friday evening activity becomes more isolated so have transitioned the mention of showers and storms to vicinity. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 81 65 79 64 / 60 50 70 40 Knoxville McGhee Tyson Airport, TN 77 63 78 63 / 70 50 80 50 Oak Ridge, TN 77 63 78 62 / 80 50 80 50 Tri Cities Airport, TN 77 61 76 60 / 60 50 80 60 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...KRS LONG TERM....BW AVIATION...KRS ####018005614#### FXPQ50 PGUM 030743 AFDGUM Area Forecast Discussion National Weather Service Tiyan GU 543 PM ChST Fri May 3 2024 .Marianas Synopsis... Latest satellite imagery is showing partly cloudy skies and isolated showers across the Marianas. Altimetry data is indicating seas of 3 to 5 feet. && .Discussion... Drier trade-wind pattern expected for the period. May see a slight uptick in showers and clouds as a couple of trade troughs pass through, with the first being late tonight into early Saturday and the second being late Saturday night into Sunday, but kept shower coverage isolated. May begin to see an increase in moisture and clouds being pulled north out of Micronesia late next week. && .Marine/Surf... Gentle to moderate trade winds are expected to continue through the weekend into next week. Combined seas of 4 to 5 feet are expected, until northerly swells enter the region. The first arrives by Sunday, while the second, larger one arrives by Tuesday, with seas rising around 2 to 3 feet. There will be a moderate risk of rip currents along east facing reefs for the next several days, with a low risk expected along all other reefs. The northerly swell will increase surf along west, north and east facing reefs and may also result in a increase in rip current risk, especially along north facing reefs. && .Eastern Micronesia and Chuuk... Trade-convergence across the region remains fragmented, with showers primarily developing along troughs moving across the region and the weak convergence trailing behind the troughs. One trough is passing near Weno in Chuuk Lagoon, bringing scattered showers to Chuuk tonight. This trough will continue to drift westward, allowing showers to decrease at Chuuk Saturday afternoon and remain isolated through Saturday night. Another trough is located near Kosrae and is producing scattered showers at Kosrae, while slowly moving towards Pohnpei. This trough is expected to reach Pohnpei late tonight, increasing showers at Pohnpei from isolated to scattered. The weak convergence east of Kosrae and passing south of Majuro is expected to strengthen over the next few days, moving across Kosrae and Pohnpei, and then into Chuuk around Sunday, promoting scattered to at times numerous showers through most of next week. Thunderstorms are expected to remain fairly isolated over the next few day due to the lack of strong divergent flow aloft. Majuro is north of the trade convergence, so showers are fairly isolated, while upper-level clouds generated by convection to the south is keeping skies mostly cloudy over Majuro. Majuro is expected to remain dry through Saturday night, before trade-wind convergence lifts northward Sunday, increasing the potential for showers at Majuro late this weekend and into next week. The northern islands of the RMI, such as Wotje, and islands north of 7N remain fairly dry and are expected to remain dry through the weekend. As the convergent trade-flow starts to lift north early next week, some of these islands may start to see some scattered showers, although this is not expected to occur until at least the middle of next week. Over the ocean, winds are expected to be from the northeast to east and mostly moderate. Combined seas, as reported by altimetry and the buoy near Majuro, are around 4 to 7 feet. Through the middle of next week, not expecting any major changes in wind or sea conditions. .Western Micronesia for Yap and Palau... Scatterometer and satellite data show that the Near-Equatorial Trough (NET) is still south of the main islands of Palau and Yap, extending westward from near EQ148E and exiting the region near 3N130E. Latest scatterometer suggests a poorly-organized disturbance or buffer circulation is embedded in the NET near 1N134E. Showers have shifted south of the main islands of Palau, so showers at both Palau and Yap are now isolated. Showers are expected to remain south of Palau through at least Sunday night and through Tuesday for Yap Proper and nearby islands as the NET and any passing trade-wind troughs are expected to remain near and south of 5N. This pattern starts to change next week as models show the NET lifting northward, as broad circulation tries to develop within the NET. This will increase the potential for showers at Palau Monday and at Yap by Tuesday night. As usual, the GFS becomes the most aggressive as it shows the circulation trying to develop as it pushes northwest into the Philippine Sea, while the ECMWF shows the circulation eventually dissipating and being reabsorbed back into the NET. What both of these models support is the potential for showers over Palau, and to a lesser extent at Yap, late next week. Winds over the ocean are expected to be fairly moderate and from the northeast to east over the next several days. Combined seas are expected to be around 4 to 6 feet through early next week, and this matches well with current heights reported by the buoys near Palau and Yap. Models are showing some north swell entering the region around midweek, but this swell is currently expected to be 4 feet or less, causing little change in overall sea heights, but may see some elevated north surf around the middle of next week. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...None. MP...None. Marianas Waters...None. && $$ Marianas: Slagle Micronesia: Schank ####018008293#### FXUS61 KPBZ 030743 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 343 AM EDT Fri May 3 2024 .SYNOPSIS... Dry and unseasonably warm weather precedes increasing precipitation chances Friday afternoon and continuing through the weekend. Cooler, but still above average, temperatures prevail Saturday and Sunday with warm and unsettled weather continuing into next week. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: - Showers and thunderstorms Friday afternoon and evening. - Temperatures well above average approaching a few records. ------------------------------------------------------------------- High pressure will retreat off to the east as a disturbance approaches from the west. Cirrus coverage will thicken and lower through the morning with increasing upper level moisture. Forecast soundings suggest another day similar to Thursday with a quickly breaking nocturnal inversion and a dry boundary layer allowing for mixing up to nearly 700 mb. The 850 mb ridge will gradually shift to the east and allow for warm advection in southwesterly flow to bring layer temperatures up to 15-16C across the area by afternoon, suggesting that high temperature will achieve the mid to upper 80s despite the cirrus. A couple sites have the potential to approach record highs (see climate section). Some lingering uncertainty in ensemble cloud coverage with suggestions for periods of scattering as cirrus push to the east lends potential for additional insolation to push temperatures up even a degree or two higher than currently forecast. This also could aid in a bit more destabilization ahead of showers and thunderstorms expected to develop by afternoon. Indications are that showers and storms pop after 17z despite copious low level dry air (LCLs 6-8kft) as convective temperatures are met and a shortwave moves through, though weak net height rises through the day are expected. Mean hi res ensemble CAPE has increased in the latest run with 600-900 J/kg; conditional on potential scattering of clouds, the 75th percentile is up to 1400 J/kg. Most guidance suggests that warm mid-levels will suppress updrafts with an equilibrium level below about 500mb. Latest CAMs suggest that the best shot for deeper convection may be across eastern Ohio where slightly less warmth and moisture in the mid-levels may allow for greater vertical growth. Even if the higher end of the instability spectrum is achieved, weak cloud bearing layer flow will present a moderate CAPE/low shear environment likely more favorable of gusty wind with brief heavy downpours. PWATs will be pushing 1.5" and upwind propagation vectors around 10 knots despite practically no low level jet suggest this potential. HREF probs for >0.5"/hr rates reach up to around 60% by evening. As a result, the Weather Prediction Center has our area in a Marginal Risk (1/5) for excessive rainfall on Friday. Record low max temperatures may be broken Friday night with persistent cloud cover not allowing for radiative cooling. Convection is favored to wane as instability is lost and the upper wave departs. Nonetheless, scattered showers will continue overnight. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... KEY MESSAGES: - Unsettled pattern remains with rain chances continuing through Sunday. Thunder possible on Sunday. - Temperatures drop, but still remain above normal. ------------------------------------------------------------------- Come Saturday, there is some suggestion the trough progression will come to a halt and allow rain to persist ahead of it being reinforced by approaching low pressure and additional shortwave support arriving from the south. The positioning of the trough will have a great influence on the weekend weather. No significant changes to the forecast for Saturday as instability looks limited to the western side of the stalled boundary/trough with a 50-60% of >500 J/kg while elsewhere plenty of low to mid level warm air will cap the environment. Total rainfall Saturday is favored in the half to three quarters of an inch range. There is good agreement the trough finally pulls through by Sunday. An area of maximized precipitation ahead of or just along the trough axis is favored, as is a greater chance for more instability to work with. Ensemble probability for CAPE >500 J/kg reaches 70-80% Sunday, but with a good amount of clouds around and a low probability of any scattering. Still, with a bit better dynamics in play and marginal instability, a few thunderstorms accompanying the trough appear possible. Most likely total precipitation amounts Friday night - Sunday night sit around 1.0-1.3", but the 90th percentile exceeds 2" primarily across the WV panhandle and western PA resultant of some convective enhancement along the aforementioned trough. This does not raise any flooding concerns for now, but may warrant watching if the higher end becomes more likely. Thick cloud coverage through the weekend will hold temperatures in check, but still above average, in the 70s. && .LONG TERM /MONDAY THROUGH THURSDAY/... KEY MESSAGES: - Rain chances continue into early next week but more uncertainty lends lower confidence. - Temperatures favored to remain above normal. ------------------------------------------------------------------- After a brief lull in the precip late Sunday night into early Monday morning as flat upper ridging slides through and surface high pressure meanders on by, rain chances again increase. Seeing some better ensemble agreement for Monday with shortwave low pressure approaching from the southwest but weakening as the responsible upper wave flattens out. High pressure to the north should keep the highest precipitation chances south of I-70. Much more ensemble spread comes into play after Monday primarily with the progression of the upper pattern as ridging tries to develop but a deep upper low across the Dakotas throws shortwave energy to the east and tries to break the ridge down. A warm front likely lifts through sometime Tuesday into Wednesday increasing rain chances again, but with uncertainty in the strength and positioning of the ridge, timing and precipitation amounts remain low confidence at this time. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... VFR conditions through most of the day, with high clouds increasing this morning and mid clouds this afternoon. Scattered showers and thunderstorms are expected to develop late this afternoon and evening. Expect locally lower ceilings and visibilities, lightning, and possibly some gusty winds to accompany any stronger storms. The probability that a storm will hit any particular port is low at this time so will use prob30 to cover the convection threat. Activity should dissipate with the loss of sunlight. Lower clouds are possible late tonight. .Outlook... Restriction potential continue through Saturday, then again early next week as multiple disturbances cross the region. && .CLIMATE... Some record highs may be approached on Friday as well as record lows on Saturday. (* denotes current forecast temperature exceeds value) 5/3 Record High Year Pittsburgh 95 1887 Wheeling 90 1942 Morgantown 88* 1965, 2012 New Philadelphia 89 2012 Zanesville 91 1938 Dubois 84 2012 5/4 Record Low Year Pittsburgh 65 1938 Wheeling 63 1931, 1939, 1941 Morgantown 63 2021 New Philadelphia 60* 2012 Zanesville 65 1902 Dubois N/A N/A && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...MLB NEAR TERM...MLB SHORT TERM...MLB/Milcarek LONG TERM...MLB AVIATION...22 CLIMATE...MLB ####018005649#### FXUS63 KGRR 030744 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 343 AM EDT Fri May 3 2024 .KEY MESSAGES... - Showers and thunderstorms taper off today - Dry Sunday into Monday - Continued Mild Next Week with Occasional Showers and Storms && .DISCUSSION... Issued at 343 AM EDT Fri May 3 2024 - Showers and thunderstorms taper off today Numerous showers and scattered thunderstorms cover the area first thing this morning. These storms have been just some good old fashioned garden variety storms with some isolated small hail and wind gusts of 30 to 40 mph winds. We will see more of the same over the next few hours, with the thunder threat diminishing a bit as the better instability shifts east. The area is under a nice moist axis, out ahead of a front that is over Eastern Wisconsin as of 07z. Instability is weak with only a few hundred J/kg of CAPE and slightly negative LI's. These parameters are just enough to produce some lightning and thunder. It looks like we should see the front gradually start clearing the area from West to East after 13-14z. With the front clearing the area, the showers and storms will be coming to and end also. We should see some sunshine break out this afternoon in the wake of the front, bring a nice half day to the area. The only thing of note tonight is the potential of low stratus advecting over the southern half of the area from the SE overnight. All of the low clouds/moisture getting swept out with the front will make a partial return overnight. The low level flow becomes from the SE, and taps the low level moisture with the front. Tough to say how far it will make it. The far SE portion of the area toward Jackson has the best chance, while the Muskegon area and areas north will see the lowest chance being further removed from the moisture source. Most of the day on Saturday will remain dry and warm. There are a couple of small chances for a little bit of spotty rain. The first is over the SE portion of the area during the afternoon. The lingering low level moisture, combined with a weakening front moving over the area may touch off a few showers/weak storms. The second area that may see a few showers late in the afternoon will be the lakeshore, with northern areas seeing the best chance. The front that meanders over the area on Saturday will be mainly dry. We do see some almost pure convergence develop along/behind the front, and a weakening short wave aloft. These factors will combine to produce a line of showers and isolated storms, possibly as early as late Saturday afternoon at the lakeshore. - Dry Sunday into Monday A weak cold front will cross the state on Saturday night into early Sunday with a few showers and storms along it. High pressure builds in behind the front providing a period of dry weather Sunday into Monday before a warm front returns north on Monday night and Tuesday. - Continued Mild Next Week with Occasional Showers and Storms Guidance pops still 70-80 percent Tuesday/Tuesday evening as Plains trough sends out a shortwave in our direction, although some timing differences on this feature are still present. The middle to late part of next week appears to remain rather active as broad/positively tilted longwave trough edges slowly in our direction. Series of fronts/troughs pivoting around a slowly approaching upper level low along with lingering warmth/instability will maintain a daily convective threat. Temperatures remaining above normal most of next week before cooling off next weekend with the eventual arrival of the upper low/trough. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 203 AM EDT Fri May 3 2024 Showers and thunderstorms continuing overnight with the heavier cells producing occasional MVFR or IFR vsbys and briefly gusty winds. Otherwise generally high-base ceilings of 5000-8000 ft and vsbys aoa 6 miles. Toward daybreak as the sfc cold front nears looks for lower MVFR to IFR cigs to arrive at MKG and GRR. This band of lower cigs with the front will continue spreading east through the morning and should impact each terminal for around 6 hours as scattered showers continue. Conditions improving to VFR Friday afternoon after the cold frontal passage with winds shifting to the northwest around 10 kts. Will have to watch for the possibility of MVFR/IFR stratus forming later Friday night, especially south and east of GRR. && .MARINE... Issued at 343 AM EDT Fri May 3 2024 It appears that we should not need any marine headlines through at least Saturday. We could be looking at a possible Small Craft Advisory event for Saturday night and Sunday. Even with the system overhead this morning, there is not much of a pressure gradient on either side of it, so no big wind events for the time being. We do see a weak front slide over the area on Saturday, and then move out by Sunday. The way the systems come together, there ends up being a decent gradient on the back side of the system that could push winds up above thresholds Saturday night into Sunday. The next potential headline event after Saturday Night/Sunday will be Monday night into Tuesday with the next system. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...NJJ/Meade AVIATION...Meade MARINE...NJJ ####018007444#### FXUS62 KGSP 030745 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 345 AM EDT Fri May 3 2024 .SYNOPSIS... Dry and warm high pressure moves off the Carolina coast as a front approaches from the west then stalls over our region for the weekend. This front will result in periodic thunderstorms and showers starting today and lingering through the weekend. A general summertime pattern sets up early next week, which will likely support scattered thunderstorm development each afternoon. && .NEAR TERM /THROUGH TONIGHT/... As of 300 am EDT Friday: Height falls will impact the East through the near term, with associated slow-moving/zonally-oriented frontal zone expected to sag toward our forecast area later today into tonight. Deep layer lift...albeit relatively weak...will approach the CWA late today into tonight, while SW flow will result in increasing levels of moisture, with forecast soundings indicating precipitable waters will be in the ~90th percentile category for the day. Therefore, conditions will become increasingly favorable for convective development as the day progresses. That being said, high and mid level clouds will continue to increase through the morning...resulting in cooler conditions than on Thursday, while mid-level lapse rates are forecast to be poor. As such, surface- based instability will be quite tame at 1000-1500 J/kg of CAPE. Meanwhile, wind shear parameters will be very unremarkable, with 0-6km bulk shear ~20 kts. So, the conditional probability of severe storms is about as close to 0 as it gets. There could be locally heavy rainfall with deeper cells and/or if an area of training cells manages to materialize. However, dry antecedent conditions should preclude a notable excessive rainfall threat. While a general decrease in coverage and intensity of convection is expected this evening, high moisture content combined with continued modest lift is expected to result in scattered convection (primarily showers) persisting well into the overnight, with perhaps a locally heavy rainfall event or two possible. Temps will be 5-10 degrees above climo through the period. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... As of 300 AM EDT Friday: Upper ridging will remain over the East Coast on Saturday before gradually pushing east into the western Atlantic Saturday night into Sunday. At the sfc the forecast area will be caught in-between two sfc highs (one over New England/SE Canada and one over the Northern Plains/Upper Midwest) as a cold front slowly approaches out of the west. The front should remain north and west of the forecast area Sunday into Sunday night. This messy pattern will lead to 850 mb S/SW'ly flow allowing for an influx of Gulf moisture across Southeast through the weekend, leading to scattered to widespread showers and thunderstorms each day. Went with likely to categorical PoPs Saturday through early Sunday evening and chance PoPs Sunday night. With PWATs expected to climb well above climo (~1.6 inches east of the mtns and ~1.3 inches across the mtns) and weak shear (~10-15 kts) leading to slow storm motion, heavy rainfall will accompany shower and thunderstorm activity. However, the overall threat for flash flooding looks to remain low due to dry antecedent conditions. Nuisance flooding cannot be entirely ruled out, especially for areas that see heavy rainfall repeatedly track over the same locations. SBCAPE looks to range from ~700-1500 J/kg each afternoon per the HRRR, GFS, Canadian and ECMWF. The NAM and NAMNest are much more bullish regarding SBCAPE through the weekend but this looks overdone as widespread cloud cover from the influx of Gulf moisture should limit destabilization somewhat. Thus, the severe potential looks rather low through the weekend thanks to the low wind shear and increased cloud cover. The SPC Day 2 and 3 Severe Weather Outlooks have the GSP forecast area in a general thunder risk which looks reasonable at this time. However, a few strong storms cannot be entirely ruled out, especially for any areas that see breaks in cloud cover. Highs on Saturday will end up near climo to a few degrees below climo thanks to SSE'ly sfc winds, convection and cloud cover. Highs on Sunday will climb to around 3-5 degrees above climo thanks to sfc winds turning more S/SSW. Lows through the short term will end up around 10-13 degrees above climo thanks to clouds limiting radiational cooling. && .LONG TERM /MONDAY THROUGH THURSDAY/... As of 330 AM EDT Friday: The workweek will kick off similar to the weekend as the aforementioned cold front remains stalled over the Lower Midwest/Ohio Valley region. This will allow for another round of scattered to widespread showers and thunderstorms on Monday. Despite SBCAPE looking slightly higher on Monday compared to the weekend, widespread cloud cover and weak shear should linger, allowing the severe weather threat to remain low. Highs on Monday will be similar to Sunday's, ending up around 3-5 degrees above climo. Lows Monday night will remain around 10-12 degrees above climo thanks to some lingering cloud cover. Drier conditions may return for most of the forecast area, with the exception of the NC/TN border, Tuesday through early Thursday as the stalled front gradually lifts northward across the Ohio Valley/eastern Great Lakes region. Convective chances increase again late Thursday into Friday as an upper low approaches out of the northwest. Highs should climb into the mid to upper 80s Tuesday through Friday, which is around 7- 12 degrees above climo. Lows should remain around 10-12 degrees above climo through the long term. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... At KCLT and elsewhere: VFR conditions are expected to persist across the Terminal Forecast Area through the morning, with steadily increasing high clouds expected. An upper level disturbance and associated moisture plume will approach the area later today, allowing for expansion of showers and thunderstorms, mainly during the afternoon and evening. Scattered coverage of convection is expected...at least across the western half of the area...warranting Prob30s for -TSRA at most sites during the afternoon/early evening. While some diminishment of convective coverage is expected this evening...showers will remain possible well into the overnight hours/early Saturday. Winds will generally be calm or light/ variable early this morning, becoming SW at 5-10 kts by afternoon. Outlook: Enhanced moisture will result in potential for scattered showers, as well as cig/visby restrictions early Saturday. A weak front is expected to become stalled in or near the area Saturday through early next week, resulting in a period of active/mainly diurnal convective weather each day. There will also be the potential for restrictions associated with widespread fog and/or low clouds each morning. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...JDL SHORT TERM...AR LONG TERM...AR AVIATION...JDL