####018010112#### FXUS61 KAKQ 040855 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 455 AM EDT Sat May 4 2024 .SYNOPSIS... On and off shower chances are expected Saturday and Sunday. Summerlike conditions return to the area for next week with daily chances of showers and storms. && .NEAR TERM /THROUGH TONIGHT/... As of 310 AM EDT Saturday... Key Messages: -Dreary conditions across the entire forecast area today with extensive low-level cloud cover and scattered showers. Yesterday's backdoor cold front is situated just south of the FA early this morning. High pressure over New England is wedging cool, moist air into the Mid-Atlantic. With the front projected to stay S of the area today, expect a dreary Saturday. Latest radar shows scattered showers, primarily W of I-95. Chances for showers will continue through the day, but with the best forcing/lift and moisture remaining to the W, the highest coverage will continue to be over the piedmont. Closer to the coast, low level moisture from onshore flow will allow for patchy drizzle to continue through the morning. Minimal thunder is expected today, but could have a few rumbles in SW counties this evening. Easterly winds will be breezy E of I-95, especially near the coast, with gusts of 15-25mph. Temps today will be cool across far northern portions of the FA. Highs will struggle to even reach 60F. Far southern portions will likely see a few breaks in the clouds and winds will have a slight southerly component, allowing for warmer temps in the mid 70s. The gradient between these warmer temps and the rest of the FA will likely be sharp, so expect most will see cooler highs in the 60s. Showers in the far western counties increase in coverage overnight with lower end chances extending E to the coast. The front will start to move back N overnight, leading to stable if not slightly increasing temps late tonight/early Sunday. Lows will be in the low- mid 50s across the N and low 60s in the S. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 330 AM EDT Saturday... Key Messages: - Continued unsettled, but warmer, Sunday. - More humid on Monday with showers and storms areawide. The front is expected to lift back N Sunday into Monday, shifting the low-level flow to the S. These factors should act to scour out the dreary conditions seen on Saturday. However, still expecting shower redevelopment in the aftn hours as temps warm into the 70s (and maybe as high as 80) and the residual front and a weak disturbance aloft remains near the area. An early look at some CAMs show that they are not particularly enthusiastic at widespread rainfall coverage, which makes sense given a lack of any focused areas of lift. Lows Sun night in the 60s. Upper heights begin building back N for Monday with high temps warming into the low 80s areawide. Despite the warmer temps, a lee trough is expected to develop in the aftn and evening hours. Combined w/ an approaching shortwave from the OH River Valley, showers and storms are expected to develop over the higher terrain in the afternoon and slide eastward into the evening. Mean LREF CAPE shows ~750 J/KG, but shear looks to be rather weak. Therefore, the severe threat looks relatively low, but cannot rule out a stronger storm or two. Soundings do show a rather saturated atmospheric column (PWATS potentially reach or exceed 1.5"), which could lead to some heavier downpours. Dew points also increase into the mid-upper 60s so the humidity will make it feel more like early summer. Shower/storm activity diminishes inland after midnight, but may linger closer to the coast overnight. Lows remain mild in the mid 60s. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 330 PM EDT Saturday... Key messages: -A summer-like pattern will bring unsettled conditions and above- normal temps. -There is the potential for severe weather mid to late week. An unsettled, summertime pattern takes over through the end of the week. A ridge aloft builds in Tuesday, then weakens slightly starting Wednesday. The GFS and ECMWF both suggest stronger 500mb flow of up to 50 kt by Wed afternoon. Additionally, several waves of weak shortwave energy will pass over the area. As of latest guidance, the strongest of these looks to pass on Thursday ahead of an UL trough dropping into the Great Lakes. A stronger system (i.e. cold front) will then cross the area late in the week. These features along with plentiful daytime heating/instability will allow for daily rounds of showers/thunderstorms. Will be monitoring this time period for severe weather given the support aloft and steep mid- level lapse rates. The CSU Machine Learning Probabilities have picked up on the aforementioned parameter space and suggest at least a slight risk for severe weather on Wednesday and Thursday for the entire area and Friday for southern/southeast areas. Highs on Tues will be in the upper 70s on the Eastern Shore and low 80s W of the bay. Well-above normal temps on Wed/Thurs with the potential for widespread 90 degree highs. Fri looks a bit cooler, but still in the 80s for most. Lows generally in the mid-60s. && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... As of 145 AM EDT Saturday... Degraded flight conditions are expected to continue through the 06z/04 TAF period as IFR to LIFR CIGs have already overspread the terminals in the wake of a backdoor cold front (with E-NE winds of 10-15 kt with gusts to 20 kt). IFR/LIFR CIGs are expected through much of the night with perhaps some improvement on Sat (to 1000-2000 ft) with continued onshore flow. In terms of precipitation, scattered showers have spread over western portions of the area, and Richmond will likely see brief periods of light rain. Areas of drizzle are also possible through Sat AM. Shower chances continue on Saturday (highest PoPs at RIC w/ lesser chances near the coast). Outlook...Sub-VFR conditions expected at times through the weekend and even into Monday due to an unsettled weather pattern. Scattered showers and tstms are expected on both Sunday and Monday. A warmer, more summerlike pattern returns by Tuesday with chances for storms each afternoon/evening. && .MARINE... As of 430 AM EDT Saturday... Key Messages: - Small Craft Advisories remain in effect for the Chesapeake Bay and lower James River through late tonight/early Sunday morning. - Small Craft Advisories remain in effect from Parramore Island S to the VA/NC for lingering seas to 5 ft. With yesterday's backdoor cold front now well S of the local area, winds have generally dropped off to 10-15 kt with gusts to 15-20 kt early this morning. However, winds are expected to increase a bit later today through tonight as low pressure lifts NE into the Great Lakes with the sfc high sliding off the coast of northern New England into Atlantic Canada. Will keep the SCAs going for the Bay/lower James for E winds increasing to 15-20 kt with gusts to 25 kt. On the ocean, have extended SCAs through 10 am for now for the zones between Parramore Island and the VA- NC border. This is where seas are still ~5ft, with 3-4 ft seas elsewhere. Depending on the increase in winds later today, these headlines may need an extension. The front lifts back N on Sunday, shifting winds to the SE/SSE. SSW winds return for Monday through the middle of next week (but likely remain sub-SCA). Southerly flow looks as though it will persist through most of next week with the next backdoor cold front possible some time Friday. && .TIDES/COASTAL FLOODING... As of 440 AM EDT Saturday... Key Messages: - Upgraded the northern Neck to a Coastal Flood Advisory through Sunday for widespread minor flooding. - Coastal Flood Statements remain in effect for the bayside of the Maryland eastern shore, with an upgrade to a Coastal Flood Advisory likely for additional rises late Sunday into Monday morning. Tidal departures early this morning average around +1.5 ft across the Bay and tidal rivers. A strong flood tidal current Fri aftn/evening has led to increasing departures into the mid/upper Bay. The pattern of elevated E winds shifting to the ESE to SE by tonight favors going above ETSS guidance across the northern Neck. As such, a Coastal Flood Advisory is in effect in this area for the next 3 high tides through Sunday aftn (an extension through Monday morning will likely be needed). Have maintained a Coastal Flood Statement for the bayside of the MD eastern shore to cover nuisance flooding for the next 2 high tide cycles. Water levels further increase here later Sunday into early Monday with an upgrade to a Coastal Flood Advisory likely as SSE winds will tend to focus the highest departures here by that time. A Coastal Flood Statement is in effect for locations on the west shore of the middle Bay to cover nuisance flooding for the next 2 high tide cycles (this may need to be extended as well). It still appears that other than locally moderate flooding at Bishops Head, this event will peak in minor flood category with the high tide cycle Sunday aftn into early Monday. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...Coastal Flood Advisory until 4 PM EDT Sunday for VAZ075>078. MARINE...Small Craft Advisory until 7 AM EDT Sunday for ANZ630>632-634. Small Craft Advisory until 4 AM EDT Sunday for ANZ638. Small Craft Advisory until 10 AM EDT this morning for ANZ654- 656. && $$ SYNOPSIS...SW NEAR TERM...AM SHORT TERM...AM/SW LONG TERM...AM AVIATION...AM/ERI MARINE...LKB/JAO TIDES/COASTAL FLOODING...AKQ ####018008014#### FXUS63 KMQT 040856 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 456 AM EDT Sat May 4 2024 .KEY MESSAGES... -Rain overspreading the UP from west to east today as a low pressure system approaches from the central Plains. -The UP remains under the preferred path for low pressure systems, with multiple notable features passing through the next week. -In between systems, dry conditions will be expected, though mostly low winds and antecedent rainfall should broadly limit fire concerns. && .SHORT TERM /TODAY/... Issued at 454 AM EDT Sat May 4 2024 Increasing clouds continue to stream into western portions of Upper Michigan early this morning per latest water vapor imagery. As a low pressure system continues its northeastward propagation toward the UP from the central Plains, that cloud cover will continue to overspread the eastern half of the forecast area as well today. And, an uptick in isentropic ascent will commence over the western counties by mid-morning as well, resulting in 30-50% rain chances by Sat 15Z in the Ironwood area. Just like the cloud cover, these rain showers will make their way eastward through the morning and afternoon hours with increasing rain probabilities over much of Upper Michigan by late afternoon. Nonetheless, the eastern third of the UP should have enough time to warm into the low 70s, unlike the western third which will struggle to reach 60 degrees with earlier onset of rain. Currently, temperatures across the area are ranging from the upper 30s across the interior to as high as the upper 40s to mid 50s along the Lake Superior lakeshore. && .LONG TERM /TONIGHT THROUGH FRIDAY/... Issued at 436 AM EDT Sat May 4 2024 Starting tonight, a broad trough will expand over the Upper Midwest and central Canada with a ridge over the eastern U.S. coast and a closed low over the western U.S. coast. A shortwave riding the middle trough will be progressing eastward over the U.P. with another shortwave not long behind it over Manitoba. The associated cold front finish progressing east across the U.P. by Sunday morning, bringing a line of showers eastward as well as a brief period of northeast gusts to 20-25 mph; a few rumbles of thunder are possible mainly earlier in the period. Lows overnight are expected in the mid 30s to mid 40s, warmest east where the cloud cover is expected to hold on the longest. The second shortwave passes just north of Lake Superior on Sunday, but no precip is expected as sfc high pressure builds in over the Upper Great Lakes. This should see cloud cover diminish, light winds, and highs in the mid 50s to mid 60s; warmest south central. Mixing increasing in the afternoon, stronger over the interior west, will bring RHs down around 40% in the east/Keweenaw with near 30-35% in the interior west. No fire weather concerns are expected at this time. With mid level ridging moving east over the Great Lakes and high pressure shifting to expand over the entire basin, the quiet weather continues with lows in the mid 30s to low 40s. Meanwhile, the closed low will have made it onshore and moved east over the Rockies, beginning to open up into a trough and take on a negative tilt. By Monday morning, the trough will be situated just over the lee side of the Rockies. High pressure means another dry day with better mixing up to ~850 mb. Stronger winds mixing down from aloft are not going to be an issue, but lower dew points will be. Minimum RHs are expected around 30-35% in the afternoon/evening hours. With highs in the upper 50s to low 70s, cooler by the lakeshores, we flirt with borderline elevated fire weather conditions. Will want to monitor these conditions in future forecast packages. The trough is expected to pivot northeast over the Plains through Monday night supporting sfc low cyclogenesis, but the U.P. stays dry yet. Monday night will be warmer than the previous night with temps only settling into the 40s, warmer in the west as clouds increase ahead of the next system. Chances for showers increase in the far west on Tuesday with increasing q-vector convergence, but likely will hold off until late morning/early afternoon when the trough begins to develop back into a closed low over the northern Plains. PVA over our region increases at this point into Wednesday morning as a shortwave cycles around the low, eventually passing northeast over the Upper Great Lakes. An approaching left exit region of the upper level jet also looks to support additional cyclogenesis over the Central Plains Tuesday night. This second sfc low then lifts northeast on Tuesday, crossing northeast over the Great Lakes Tuesday night resulting in an uptick in PoPs Wednesday night. Meanwhile, the stronger sfc low associated with the mid level low will spin over the Northern Plains. With the given spread in the guidance, opted to leave the NBM PoPs Tuesday onward. There is a chance for thunderstorms on Tuesday and Wednesday, but confidence remains low at this point given the spotty instability noted in the guidance; best chances are on Tuesday when the mid level lapse rates and bulk shear are higher. Slight chances for showers gradually diminish through the end of the work week as we begin to see a pattern shift. Longer range ensemble guidance hints at positive 500 mb height anomalies over the western U.S. with negative height anomalies moving toward the east coast toward the latter part of May. This means less moisture from the Gulf of Mexico to support precip chances and cooler northwest flow over the Great Lakes. The drier trend is captured well by CPC precip outlooks out to 3-4 weeks with a cooler pattern more within the next 8-14 days. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 128 AM EDT Sat May 4 2024 VFR conditions continue into Sat morning as weak ridging continues to affect the area. Starting late tonight, another low pressure over the Central Plains lifts northeastward towards the Upper Midwest and brings more rainfall to the west as soon as Saturday afternoon. This incoming rainfall will bring MVFR and possibly lower conditions to across KIWD, MCMX and KSAW by the end of the TAF period. && .MARINE... Issued at 436 AM EDT Sat May 4 2024 Southwest winds this morning become northwest mid morning over the west half of Lake Superior as a weak low pressure lifts northeast into the region. Winds across the rest of the lake turn northeast behind a cold front this evening as the low lifts northeast into northern Ontario. The eastern portions of Lake Superior could briefly see some northwest wind gusts up to 25 kt tonight into Sunday morning. As high pressure settles over the lake Sunday and Monday, winds will be below 20 kt until Monday afternoon. A strong low pressure system over the Northern Great Plains will cause gusty northeasterly winds to funnel towards Duluth Harbor to around 20-25 kts monday afternoon into Monday night. Meanwhile, a second weaker low pressure develops over the Central Plains, lifting northeast toward the Upper Great Lakes on Tuesday. The track and timing of this secondary low is still not totally solid, but east winds to 20-30 kts are likely Tuesday into Tuesday evening as it moves through the Great Lakes Basin. Probability of Gales remains low at this time. (<20% chance of winds exceeding 34 kts). Winds look to hold around 15-25 kts through the rest of the work week. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...TDUD LONG TERM...Jablonski AVIATION...07 MARINE...Jablonski ####018003718#### FXUS65 KTWC 040857 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 157 AM MST Sat May 4 2024 .SYNOPSIS...Sunny, warm, and dry to start the weekend. A dry weather system will bring stronger breezes to windy conditions with possible blowing dust on Sunday. Cooler Monday than temperatures warm up the remainder of next week with continued afternoon breezes. && .DISCUSSION...A Pacific weather system has started to move into the western coast states based on the latest satellite imagery. Southeast Arizona will start to feel the impacts today with a little more breezier day compared to yesterday. Another ground hog's day of high temperatures in the upper 80s to lower 90s. By Sunday, the weather system will pass to the north and creating a tighter pressure gradient to bring strong gusty southwesterly winds. The latest guidance on speeds have come down slightly, but the probability of exceeding a gust greater than 45 mph is at least: 5% in Tucson; 22% Douglas; 46% Willcox; 59% Safford; and higher values along ridge tops and in valleys with southwest orientations. Overall, Southeast Arizona could experience sustained winds of 20-30 mph with gusts up to 45 mph. Can't rule out blowing dust impacts in the afternoon due to fine dry soils around the region. This also leads to fire weather concerns because of the combinations of strong gusty winds, low relative humidities, and a high fire danger. Thus, a Fire Weather Watch is still in effect for Sunday morning to the evening. Monday, the weather system will move out east and resulting in cooler daytime temperatures and stronger breezes, especially out east in Graham, Greenlee, and Cochise Counties. For the rest of the week, temperatures will warm up back up to above seasonal normal with the continuation of afternoon breezes. && .AVIATION...Valid through 05/00Z. FEW-SCT clouds AOA 20k ft AGL and then clearing west to east after 04/20Z. SFC wind generally light and variable this morning. After 04/19Z, SFC winds favoring SWLY/WLY at 10-16 kts and gusts up to 24 kts, with the strongest SFC wind east of KTUS in the vicinity of KDUG and KALK. After 05/03Z, winds generally favoring SLY at less than 12 knots till the end of the forecast period. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...High temperatures will be 2-5 degrees above normal through Sunday and then within a couple of degrees of normal next week. Today, 20-ft winds will generally be 15-20 mph with min RHs values of single digits to teens in the valleys and in the teens for the mountains. By Sunday, dry weather system will move to our north, resulting in windy southwest winds of 20-30 mph and gusts to 40-45 mph across most of southeast Arizona. Breezy afternoon and early evening conditions then persist much of next week, especially to the east of Tucson. Min RHs values in the valleys will be in the single digits to lower teens, with values generally in the teens for the mountains. On Sunday, the combination of strong and gusty southwest winds, low relative humidity levels, and a high fire danger rating will result in near critical to critical fire weather conditions from the late morning through early evening hours. A Fire Weather Watch has been issued for all of southeast Arizona from 11 am to 7 pm MST Sunday. && .TWC WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Sunday morning through Sunday evening for AZZ150>154. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson ####018006362#### FXUS63 KIWX 040859 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 459 AM EDT Sat May 4 2024 .KEY MESSAGES... - Active weather pattern for this week, with chances for showers and storms every day. The best chances will be Tuesday into Thursday when a stronger low pressure system moves through the area. A few strong to severe storms are possible Tuesday afternoon into Wednesday, but confidence is low at this time. - Temperatures linger in the 70s and low 80s through most of the week, except Sunday when highs north of US 24 will be in the 50s and 60s, coldest near Lake Michigan. Next weekend lows will be in the 60s. && .DISCUSSION... Issued at 458 AM EDT Sat May 4 2024 Mostly dry today as a weak surface high lingers in place, with mid level ridging breaking down somewhat late this afternoon thanks to an approaching trough. There is a stationary front settled just to the southeast of our CWA, oriented from roughly southern Ontario southwest towards Lima, OH and down into Saint Louis, MO. This will be a focus for shower activity, maybe a few storms, into the afternoon-with the best chances after 18z as we build up some instability. Going by the NAM, it looks like we'll have around 500- 1000 J/kg of sfc based CAPE by 21z largely east of I 69 (more like 200-500 J/kg west), in addition to weak moisture advection from the southeast and mid level lapse rates of around 7 C/km. We have a subsidence inversion to overcome and weak forcing overall, but felt 20-30 percent pops were warranted for the east. Luckily the bulk effective shear for the afternoon time period is less than 20 knots, so if any storms develop, don't expect much in the way of severe weather. Otherwise, expect partly to mostly sunny skies with increasing clouds towards the evening. Highs will be in the 70s. Late this afternoon into tonight, a surface low and mid level trough will move through, bringing better chances for rain and some storms that dwindle with eastward progression. SPC Day 1 outlook has all of our area in general thunder, with the marginal risk for severe weather to the west of our CWA associated with the system, where wind shear is more on the order of 25-35 knots and the cold front is moving through during more favorable time of day. For us, the shear weakens to about 20-30 knots, with waning instability-so while I have higher pops west tonight (40-60 percent) I dropped them off to 20-35 percent further east with lesser chances for thunder. Severe weather is not expected at this time. Lows will be in the 50s and 60s, warmest inland from Lake Michigan. Isolated/scattered showers & storms will persist east of I 69 through Sunday evening-largely associated with the slowly exiting cold front. Again, minimal shear with around 500-1000 J/kg of sfc based CAPE by Sunday afternoon in the east warrants 20-30 percent pops, however, severe weather is unlikely. Highs will be in the 50s and 60s north of US 24 (coldest near Lake MI) and the low to mid 70s south. Otherwise, expect partly to mostly sunny skies. For most areas, Sunday night into late Monday night will be dry thanks to an amplifying mid level ridge and an expansive surface high sprawling over the Great Lakes. A low pressure system approaching from the southwest Monday afternoon and evening will bring increasing chances for showers and maybe a few thunderstorms south of US 24, but confidence is low (it could miss us to the south all together). Highs will be in the upper 60s and low to mid 70s. Tuesday into Wednesday will be the best shot at more significant precipitation and even thunderstorm chances. An upper level low dives into the north central CONUS and develops a surface low somewhere over IA/MO/KS Tuesday afternoon, lifting it through the Great Lakes as it deepens. The low is forecast to reach southern Ontario roughly Wednesday evening. The warm front moves through Tuesday, followed by the cold front on Tue Night/Wed Am, with decent moisture transport out ahead of the low. Kept the 50-90 percent chances Tuesday into Tuesday night, with thunderstorms likely. I suspect that we have potential for severe weather if this pans out as the models currently suggest, with 40-65 knots of bulk effective shear and 500-1500 J/kg surface based cape by Tuesday afternoon/evening. At this time, we are in the 15 percent for the western half of the CWA for the Day 4 SPC outlook, and think it's definitely worth monitoring. The upper low over the central CONUS will gradually migrate eastward into the Great Lakes by Friday afternoon, lingering through the weekend and bringing additional chances for showers and storms, particularly Thursday. A secondary low develops behind the Tue/Wed system in much the same location, drifting over the forecast area through the day and bringing potentially heavy rain-but too far out to add much detail at this point (we are in the WPC Excessive Rainfall Outlook Marginal Category for Wed/Thu). Temperatures linger in the 70s and low 80s until the weekend, when we cool into the 60s for highs (40s and 50s for lows). && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1230 AM EDT Sat May 4 2024 Lingering boundary layer will likely allow a high MVFR to low VFR stratocu deck to settle in over KFWA through much of the forecast period. Drier air has worked into KSBN where lesser diurnal cu coverage is anticipated mid morning into the afternoon. Models do try to generate isolated showers in the vicinity of KFWA later this afternoon as weak surface based buoyancy develops on the western fringe of a stalled OH trough. However, point chances are too low for a mention in the TAF at this time. A sfc trough does approach KSBN toward the end of the period (3-6z Sun) with non-zero chances for decaying showers/iso storms. May opt to add in at least a VCSH with the 12z issuance if this signal persists. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...MCD AVIATION...Steinwedel