####018007475#### FXUS61 KGYX 031031 AFDGYX Area Forecast Discussion National Weather Service Gray ME 631 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 /UNTIL 7 PM THIS EVENING/... Impacts: *No significant weather impacts expected 1030 AM UPDATE...Breaks in the clouds are making for a sunny morning in many places. Fog is still present in many of the valleys, but that is expected to dissipate over the next couple of hours. This update was the usual refreshing of near term temperature, dewpoint, and sky trends with observations. Previous Discussion... 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 /7 PM THIS EVENING THROUGH 6 PM 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 /12Z 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 ####018004816#### FXUS63 KDTX 031031 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 631 AM EDT Fri May 3 2024 .KEY MESSAGES... - Numerous showers hang around today, with a chance of non-severe thunderstorms. - High pressure fills in briefly on Saturday offering drier weather ahead of the next weak cold front that tracks through SE Michigan early Sunday morning. - Seasonably warm temperatures expected through early next week with high temperatures in the low to mid 70s. && .AVIATION... Upper level short wave energy, weak elevated instability and deep layer moisture advection along/in advance of surface low pressure and a warm front will sustain areas of showers this morning. Waning elevated instability will limit the risk of additional thunderstorms this morning. Area observations continue to support VFR ceilings for at least the next two to three hours. Continued influx of low level moisture along with the ongoing rain will result in increased chances for MVFR based ceilings after 15Z. A decrease in the overall coverage of showers is expected in the 15 to 18Z time frame. This will open the door to some weak diurnal destabilization, supportive of a chance of thunderstorms (mainly across Metro Detroit) late this afternoon and evening. The sfc low and cold front will progress from northwest to southeast across the forecast area between 19Z and 00Z, leading to a post frontal wind shift to the NNE along with some improvement in ceilings. For DTW/D21 Convection...Additional chances for thunderstorms across the airspace will be more or less isolated, less than 20 percent, this morning as elevated instability wanes. Convective redevelopment is forecast this afternoon along a cold front. A scattered line of showers and thunderstorms is forecast to traverse the airspace between 21Z and 01Z. DTW THRESHOLD PROBABILITIES... * Low for thunderstorms today. * Moderate for ceiling 5000 ft or less this afternoon and tonight. && .PREV DISCUSSION... Issued at 320 AM EDT Fri May 3 2024 DISCUSSION... Large upper level low/trough over Central North American early this morning, with the center along the northern Minnesota border. The 500 MB low (~540 DAM) will track off to the northeast, reaching Hudson Bay Saturday morning. Deep southwest flow will maintain above normal temperatures over southeast Michigan right through the weekend. Moisture advection has peaked out with the broad 850-700 MB Theta-E ridge axis extending north, through the Central Great Lakes. Still looks like lingering showers around today with possible thunderstorms as a ribbon of upper level PV approaches from the southwest. Severe weather not expected with weak mid level lapse rates and MLcapes under 750 J/kg. Height rises/surface ridging expected on Saturday, leading to mainly dry conditions during the day. Low clouds trapped underneath subsidence inversion, with perhaps a bit of drizzle/very light showers toward the southern Michigan border where the higher dew pts reside. Weak height falls/cold front then on track to move through through Saturday night, worthy of chance pops, despite the bulk of the forcing over northern Great Lakes. Western confluent upper level flow Sunday preceding an upper level ridge axis arriving early next week, supporting at least a 48 hour window of dry and pleasant weather. MARINE... A low pressure system will then track through the northern Great Lakes today pulling the warm front up through the region early in the day. This will allow winds to flip around to the south-southwest which will bring in a warmer airmass, helping to keep gusts down. Scattered showers and thunderstorms will focus on this morning warm frontal passage and may persist into the afternoon. Showers and thunderstorms then increase coverage once again in the evening as the cold front gets pulled through the region. Brief area of high pressure brings quieter weather on Saturday. Winds will flip around to the northeast behind the cold front tonight, but the area of high pressure will keep winds below 20 knots. Southerly winds will redevelop Saturday night ahead of the next cold front that will sweep through Sunday, but will turn northwesterly behind the front Sunday afternoon. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....SC DISCUSSION...SF MARINE.......SF You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit. ####018006911#### FXUS62 KILM 031032 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 632 AM EDT Fri May 3 2024 .SYNOPSIS... Dry and warm weather will continue today. Scattered showers and thunderstorms will develop this weekend as a front approaches from the west. High pressure will build overhead by Tuesday with well above normal temperatures likely during the middle and late portions of next week. && .UPDATE... Patchy dense fog has developed across the forecast area. Dense fog is limited in scope and duration in many areas, thus a Special Weather Statement was issued instead of a Dense Fog Advisory. Fog should dissipate by 9AM EDT. && .NEAR TERM /THROUGH TONIGHT/... Still expecting fog development this morning, although confidence in how much and how dense is lacking. Based on dewpoints, boundary layer moisture is a little lower than last night and boundary layer winds are a kt or 2 stronger. There are also cirrus clouds moving in from the northwest. Overall the environment seems less favorable for widespread dense fog, but still expect to see fog development in the pre-dawn hours, especially closer to the coast. Fog that does develop will be quick to dissipate, likely doing so before 8AM. Bermuda High off the coast and weak shortwave ridge aloft will offer a glimpse of summer today. Very dry air aloft remains over the area with precipitable water struggling to hit 1". While these values aren't far off climatological values for early May, the bulk of the moisture is in the lowest 1k ft and above 25k ft. The RH between 700- 500mb drops into the single digits and a weak subsidence inversion is evident in forecast soundings. Once fog and low clouds from this morning dissipate, skies will be mostly sunny with patches of high cloud moving across the area at times. Some flat cue is possible along the afternoon sea breeze, but the region will remain dry. Late tonight a weak shortwave, bursting with moisture, rides up the west side of the shortwave ridge. This feature will spread cloud cover over the forecast area in the evening/overnight and may have weak, scattered convection just west of the area by 12Z Sat. Given the abundance of dry air and the relatively weak nature of this feature think measurable rain before 12Z Sat is unlikely. Temperatures will run well above climo today and tonight. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Low level thicknesses depict a weak cold front stalled across the NC/SC Piedmont on Saturday. This weak boundary will be the focus for unsettled weather on Saturday and Sunday. As ridging pushes offshore, weak vorticity will advect northward along the western extent of the ridge. This energy, while not robust, should help to develop showers and storms across the area on Saturday in conjunction with the existing surface front. Mid and high level moisture advection across the region will result in thick cloud cover early in the day. Early cloud cover will impact instability, which model soundings continue to keep rather weak. There is some uncertainty in the position of the front and resulting coverage of showers and storms. Low level thicknesses are having a hard time depicting the front, even west of the mountains, therefore there is a question as to how far east the front will move. For now, I have kept PoPs fairly high with multiple potential forcing mechanisms and increasing moisture depth, even in weak instability. Developing sea breeze along the coast and poor low level saturation on the western edge of a ridge should keep coastal areas mostly dry on Saturday. With a potential surface front near the I-95 corridor, PoPs increase rapidly as you head inland. Temperatures generally in the lower 80s due to the increased cloud cover. Shortwaves on the western extent of the ridge will start to push eastward overnight with showers and a few remnant storms approaching the coast. Overnight lows in the mid 60s. A similar day on Sunday, albeit with better saturation and resulting instability, particularly along the coast. High temperatures should still reach the lower 80s. Developing sea breeze will increase shower chances. Less cloud cover overnight with similar morning lows; mid 60s. && .LONG TERM /MONDAY THROUGH THURSDAY/... Maintaining shower and storm chances for Monday. This is especially true along the sea breeze which will be bolstered by increasing southerly flow. An approaching shortwave Monday night into Tuesday will keep showers and storms in the forecast overnight. Weak ridging builds behind the shortwave on Tuesday, but warmer temperatures will produce better instability. A few afternoon storms are possible, typical of a diurnal warm-season pattern. High temperatures in the mid and upper 80s will be the start of a warming trend through Thursday. Southeastern US ridge amplifies on Wednesday and Thursday, bringing high temperatures well above normal. Lower 90s are expected each day. SW winds will pin the sea breeze near the coast, keeping coastal sites above normal as well. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... Range of VFR to IFR visibility and ceiling across the region this morning. Majority of the area will be VFR by 12Z. A few sites may hold onto IFR beyond 12Z, but by 13Z all sites should be VFR. Light winds continue today with another round of fog and low stratus possible tonight, although looking more like it may be an MVFR event vs IFR, will depend on cloud cover overnight. Extended Outlook...Scattered mainly diurnal convection will bring brief visibility restrictions in heavy rain Saturday through Monday, especially inland affecting KFLO and KLBT. Lightning is also possible. && .MARINE... Through Tonight... Light southerly flow continues today as Bermuda High remains the dominant feature. Weak sea breeze will develop in the afternoon which may bump winds near shore to around 10 kt. Seas 2 ft or less continue to be a mix of a dominant southeast wind wave and a weak easterly swell. Saturday through Tuesday Night... Bermuda high will maintain SE flow this weekend, becoming southerly on Sunday around 10 knots. Winds increase early next week as winds turn S and SW. SW flow by Tuesday will increase to 10-15 knots. Seas 1-2 feet this weekend, increasing to 2-3 early next week. Low impact easterly swell will continue through the period. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...None. SC...None. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...III NEAR TERM...III SHORT TERM...21 LONG TERM...21 AVIATION...III MARINE...III/21 ####018007528#### FXUS66 KPQR 031034 AFDPQR Area Forecast Discussion National Weather Service Portland OR 334 AM PDT Fri May 3 2024 .SYNOPSIS...Dry start to the morning before the next system brings heavier rain this afternoon into Saturday. No widespread hydrological concerns expected. Snow levels will rise above 7000 feet today, then fall back down to Cascade pass-level tomorrow. Expect another round of advisory-level snowfall above 3500 ft this weekend. Cool, wet, unsettled weather likely continues through early next week. Pattern change into drier and warmer weather begins Wednesday through late next week. && .SHORT TERM...Today through Sunday night...Satellite imagery as of 3 AM PDT depicts mostly clear skies over northwest Oregon and southwest Washington except for a few areas of low stratus. High clouds associated with the next low pressure system are approaching the Pacific Northwest and will gradually filter in this morning. Dry conditions will also prevail this morning transient high pressure aloft pushes through the area. Expect rain to begin at the coast around 12-1 PM and spread into the Willamette Valley by 2-3 PM as the system's warm front lifts over the area. Rain will continue tonight into Saturday morning as the trailing cold front pushes through. This system will have an abundant amount of moisture as IVT values max out around 300-400 kg/ms this evening. Models still show precipitable water values around 1 inch, which is about two standard deviations above normal for this time of year. There have been minimal changes the total QPF forecast with this system. Still expect around 1-1.5 inches for the interior lowlands, and 1.5-2 inches for the coast and mountains from late morning today to tomorrow (Saturday) afternoon. No impactful winter weather is expected for the Cascade passes today as snow levels will rise above 6500 to 7000 feet. Despite the impressive QPF forecast amounts for early May, no hydro concerns are expected thanks to the quick-moving nature of this system. HEFS probabilistic guidance continues to show a less than 5% chance of reaching action stage for the majority of rivers. Two rivers with the highest chances of reaching action stage are Marys River at Philomath (5-10% chance) and Tualatin River near Dilley (15% chance). As the low pressure system progresses southward toward California tomorrow, cold air aloft will return and snow levels will fall back down to around 3500 to 4000 feet. We'll still continue to see precipitation this weekend, so another round of winter weather will be in store at pass-level. A Winter Weather Advisory has been issued above 3500 feet for the North Oregon Cascades to the Lane County Cascades from 5 AM Saturday to 11 AM Sunday morning. These locations are forecast to receive around 4 to 10 inches of snow, except up to 16 inches for the highest peaks above 5000 feet. Those traveling through the passes this weekend should prepare for winter weather conditions. Meanwhile, the lowlands will continue to see rain showers through the weekend. -Alviz && .LONG TERM...Monday through Thursday...The early part of next week continues to look cool and showery as ensembles from WPC cluster analyses show upper level troughing across the Pacific Northwest through Tuesday. Still not seeing any signals for particularly notable QPF in any one period beyond Saturday, but area rivers will likely continue to run high for this time of year as episodic bouts of rain continue across the region. Temperatures through Tuesday will continue to run below normal, with daytime highs struggling to get out of the 50s. On Wednesday, ensemble guidance begins to suggest drier and warmer conditions as an upper level ridge builds over the NE Pacific and extends into our area. By Thursday, WPC clusters suggest that the ridge strengthens further over the Pacific Northwest, leading to clearing skies and a quick rise in daytime temperatures. NBM suggests a 30-50% chance that afternoon highs on Thursday exceed 70 degrees for interior lowlands. This trend looks to continue going into next weekend. -Alviz/CB && .AVIATION...High clouds slowly filtering into the area ahead of next frontal system. Generally VFR with areas of MVFR, mainly south of a KTMK-KSLE. May also see patchy fog or low stratus bringing IFR conditions through 14-16Z Fri. The front properly moves ashore around 20z Fri, reaching the Willamette Valley around 22z Fri to 00z Sat. Model guidance indicates around a 60-70% chance of high end MVFR conditions at that time at all terminals. The southern coast (KONP) sees the most precipitation trained there, and around a 70% chance of IFR conditions is expect at that time. These probabilities continue through 12Z Sat. With deep moisture, expect mountains to become obscured. Winds remain fairly variable and light (<5 kt), but once the front nears, winds will take on a stronger southerly character. Winds at coastal terminals will begin to gust to around 22-24 kt from the south around 20-22z Fri, then gradually veer more southwesterly and weaken through the rest of the TAF period. PDX AND APPROACHES...VFR conditions under nearly clear skies. Good radiational cooling, but east wind around 5-7 kt holding RH values around 80-85 percent. However if winds ease, may see for or low stratus form. HREF indicating at 10-20% chance for IFR cigs through 16Z. So for now will not include in TAF, but keep an eye out for changes. The front pushes in right around 00z Sat with around a 50-60% chance of high end MVFR ceilings develop shortly afterwards at 03z Sat. Chances increase to around 80% after 06Z Sat. Winds generally east through about 00Z Sat then more south to southeasterly. A surface trough may hang up on the coast to maintain more of s southeast wind into the night. /mh && .MARINE...Weak high pressure over the waters early today gives way to a cold front associated with a low dropping out of the Gulf of Alaska. Winds along the coast will not be as high as the outer waters as they are not aligned directly to the coastline. Winds will be in the 15 to 20 kt with gusts to 30 kt range from 10-60 NM. The north Oregon and central Oregon inner waters may still see isolated gusts up to 25 kt this afternoon. Due to a lack of widespread increased winds, have decided not to issue a small craft advisory for the inner waters. However, there remains a slight probability in the case the low tracks a little further north than currently project. Winds ease this evening, but expect to see a period of steep seas (6 to 8 ft at 8 to 9 seconds) through Saturday morning, possibly longer, so have extended the Small Craft Advisory until 11 AM Sat. Will have to watch for steep seas reaching the inner waters on Saturday. /mh && .PQR WATCHES/WARNINGS/ADVISORIES... OR...Winter Weather Advisory from 5 AM Saturday to 11 AM PDT Sunday for ORZ126>128. WA...None. PZ...Small Craft Advisory from 8 AM this morning to 11 AM PDT Saturday for PZZ271>273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland www.twitter.com/NWSPortland