####018005737#### FXUS61 KBTV 040755 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 355 AM EDT Sat May 4 2024 .SYNOPSIS... High pressure remains over the region today and will bring one more day of dry and mild weather. Widespread rainfall returns for Sunday, and some isolated non-severe thunderstorms are possible, particularly over northern New York. A period of warmer and sunnier conditions are expected for the start of the week, with more unsettled weather returning by the middle of the week. && .NEAR TERM /THROUGH SUNDAY/... As of 355 AM EDT Saturday...An occluded front is currently decaying as it is moving across the North Country due to a stubborn ridge of high pressure over the region. The front has been able to bring a couple showers to northern New York, but those should mostly fall apart before they reach Vermont. Light southeasterly flow is helping to advect a cooler maritime airmass into areas east of the Greens and it is creating a relatively sharp temperature gradient tonight. Lows east of the greens will be in the 40s but the in the Champlain and St. lawrence Valleys, temperatures will only fall into the mid to upper 50s. Any showers over northern New York should fall apart by daybreak so Saturday will be a mostly dry day. Some high clouds will linger into the day but they should be thin enough to allow a decent amount of sunshine, particularly over Vermont. Temperatures will climb into the 60s to around 70, very similar to yesterday. Another front slowly moves across the region Saturday night into Sunday, and with some connection to gulf moisture, it will bring more meaningful precipitation. Most areas should see up to around a half inch of rain so there are no flooding concerns. Some elevated instability should develop during the day on Sunday, particularly over northern New York, so some thunderstorms and heavier convective showers are possible. However, there is no severe threat. A southerly low-level jet will pass over the region on Sunday and will cause some channeled flow in the Champlain Valley. Winds could gust up to 30 kts over Lake Champlain. However, winds will be limited by the water temperatures being colder than the air and by the strongest winds occurring when the precipitation is falling. These two factors will limit the ability for the stronger winds to mix down. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... As of 355 AM EDT Saturday...Widespread rain showers will be ongoing Sunday night as a frontal boundary moves across the region. Although it won't be all that much colder behind the front, the incoming airmass will be much drier, so expect showers will rapidly come to an end by early Monday morning. Another weak surface trough will move through Monday afternoon, which may allow a few additional showers to develop, but any activity would be isolated and very light in nature given the dry air that will be in place. Ridging spreads into the area Monday night, keeping conditions dry. Monday's highs will top out in the mid 60s to low 70s, with the warmest conditions occurring where sun can break through the clouds. Lows both Sunday night and Monday night will mostly be in the 40s, though Sunday will be more in the mid 40s to around 50F, while Monday night will be a little cooler. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 355 AM EDT Saturday...Tuesday will be dry as we remain under the influence of ridging, but then precipitation chances will increase by Wednesday and continue through the remainder of the week as several waves move through the nearly zonal flow aloft, and eventually around a developing upper trough centered to our north. Exact timing and placement of these waves and associated precipitation is difficult to pinpoint at this juncture, but expect every day through the latter half of the week to have at some chance of showers. Instability doesn't look all that impressive, though a few rumbles of thunder may be possible Wednesday over western sections of northern NY, and perhaps far southern VT on Thursday. Tuesday will be the warmest day under lots of sunshine; highs will be in the mid 60s to low 70s. Things should cool down slightly thereafter, though exactly how much will depend on exact timing and placement of shower activity and cloud cover. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... Through 06Z Sunday...VFR conditions should persist through the entire TAF period though moist southeast flow could cause ceilings at MPV to lower to MVFR Saturday night. A few light showers are possible tonight at MSS and SLK but they will not be heavy enough to cause any visibility concerns. Wind shear has either met LLWS criteria or is very close to meeting it at all the terminals. The wind shear should continue for the rest of the night before lowering during the day. Winds will be relatively consistent through the entire TAF period, generally light from the southeast though MSS should be light out of the northeast. Outlook... Sunday: Mainly MVFR, with areas VFR possible. Definite SHRA. Sunday Night: Mainly MVFR, with areas IFR possible. Chance SHRA. Monday: Mainly VFR, with local IFR possible. Slight chance SHRA. Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX. Tuesday Night: VFR. Slight chance SHRA. Wednesday: VFR. Likely SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Myskowski NEAR TERM...Myskowski SHORT TERM...Hastings LONG TERM...Hastings AVIATION...Myskowski ####018006842#### FXUS61 KPBZ 040757 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 357 AM EDT Sat May 4 2024 .SYNOPSIS... Intermittent rain and a few storms are possible through the weekend. With clouds and rain, temperatures will be cooler today, but will rebound Sunday as a southerly flow returns. A brief break in the rain is possible Monday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... KEY MESSAGES: - Showers taper off overnight. - Showers slowly move back over the region later this morning. - Cooler temperatures today. ------------------------------------------------------------------- East coast ridge will move very little today and amplify this morning in response to trough digging into the northern Plains. We will continue to rest on the western side of the ridge where a shortwave will drift northward throughout the day. Deep moisture will flow northward on the backside of the ridge axis keeping in plenty of clouds and the risk for showers all day. An increasing southeasterly flow at the surface will pump Atlantic moisture into the region aiding in the shower development. For the most part, rainfall should be on the light side. HREF probs for 24 hour rainfall ending at midnight tonight for >0.25 generally range from 30 to 50% with some pockets of 60 to 70% over portions of northern WV and the higher elevations. Clouds, showers and a cool easterly flow will keep temperatures slightly below normal today. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... KEY MESSAGES: - Unsettled pattern remains with rain chances continuing through Sunday. Thunder possible on Sunday. - Temperatures push back above normal Sunday and Monday. ------------------------------------------------------------------- East coast ridge will flatten and drift eastward on Sunday. The shortwaves riding northward on the western flank of the ridge will also shift to the east. Shower coverage looks to dissipate Sunday morning. A weak cold front will slowly cross Ohio Sunday. Models are hinting that scattered storms could develop ahead of the front Sunday afternoon. However, ample cloud cover,limited instability, and lack of upper level support should work to shunt storm development and intensity. Temperatures will warm on Sunday as the low-level flow veers to the southwest ahead of the front. Ensembles have been consistent in showing a shortwave trough over the Middle Ohio Valley approaching, but weakening, on Monday as it interacts with a weak ridge over our region. A south-to-north gradient in PoP values still seems appropriate for the Monday/Monday night period. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... KEY MESSAGES: - Rain chances continue next week but more uncertainty lends to lower confidence. - Temperatures favored to remain above normal. ------------------------------------------------------------------- Uncertainty still reigns after Monday. Most guidance depicts a ridge centered over the Great Lakes at 12Z Tuesday, along with a deep closed upper low in or near the Dakotas. The upper low appears likely to fill during the midweek period, and as it does so, shortwaves rotating around it appear to flatten out the ridge as it moves across the Upper Ohio Valley, finally eroding it almost completely in the northeast CONUS. Some strength and timing issues remain with the details of this process, which in turn could impact precipitation amounts and timing. Nevertheless, a warm front is likely to cross on Tuesday as the ridge progresses eastward. This will lead to the persistence of a warm and moist airmass, with precipitable water values at or above the 90th percentile in the climatology. Along with the previously mentioned shortwave activity, this will keep an active weather pattern in place for our region, with decent daily precipitation chances through Friday. Deep-layer shear will increase as well behind the departing ridge, so severe weather chances will need to be monitored as well. According to CSU machine-learning guidance and NBM CWASP probabilities, Wednesday and Thursday may be the days to watch. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... VFR ceilings and scattered light showers are ongoing across the area this evening. Removed the mention of thunder from 00Z TAFs as instability is waning and any lingering occurrences of lightning would be brief and isolated, with little impact to area terminals. Into tonight, convection is expected to subside in coverage, with only some light lingering showers possible primarily southeast of a ZZV-PIT-DUJ line. Meanwhile, saturation from the rain and cooling temperatures may allow an MVFR cloud deck to settle in by daybreak as winds shift to southeasterly. The highest probabilities for ceiling restrictions, per the latest hi-res ensemble guidance, exist north and west of Pittsburgh, across portions of eastern Ohio and northwestern PA. East of PIT, it appears downsloping southeasterly winds may help keep low-level moisture profiles slightly less saturated and thus, mitigate the formation of widespread MVFR/IFR ceilings. Widespread rain chances increase again after 18Z Saturday. Locally lower ceilings and visibilities can be expected in the heavier showers. Continued to leave thunder out of the TAFs during that period given uncertainty surrounding how much instability will develop. If lightning does occur, the best chances according to hi-res ensembles would be southwest of PIT, so a mention of thunder at ZZV and HLG may be needed in future updates. .Outlook... Restriction potential continues through Sunday morning, with additional storm chances Sunday afternoon. Periodic restrictions may continue through early next week as multiple disturbances pass through the region. && .CLIMATE... Some record warm minimum temperatures may be approached on Saturday. Below is a table showing the latest forecasted low temperature for each climate site, their respective record value, and the year it was set. Forecast Record Year Pittsburgh 60 65 1938 Wheeling 62 63 1931, 1939, 1941 Morgantown 61 63 2021 New Philadelphia 60 60 2012 Zanesville 63 65 1902 && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...22 NEAR TERM...22 SHORT TERM...22/CL LONG TERM...CL AVIATION...Cermak/Milcarek CLIMATE... ####018008136#### FXUS61 KLWX 040759 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 359 AM EDT Sat May 4 2024 .SYNOPSIS... A stalled frontal boundary will remain draped to the south of the forecast area throughout the weekend, bringing on and off showers and possible thunderstorms. A secondary cold front will move through the area on Monday before lifting as a warm front on Tuesday. This will bring a prolonged period of unsettled weather through next week. && .NEAR TERM /THROUGH TONIGHT/... A cold front will remain stalled just west of the forecast area throughout the day, bringing rain showers and perhaps a rumble of thunder. Onshore flow will provide plenty of moisture for cloudy skies, rain showers, and drizzle throughout the day. Temperatures will be noticeably cooler today with highs in the mid 50s to mid 60s. Cooler conditions combined with plenty of cloud cover will hinder thunderstorm development. WPC has the westernmost portions of the forecast area in a marginal risk for excessive rainfall. Isolated instances of flooding are possible, though dry antecedent conditions and 24-hour QPF values less than an inch will lead to most of the rainfall being beneficial. Rain showers continue overnight with thunderstorm chances dwindling this afternoon. Moisture aloft will deepen overnight, leading to heavier rainfall overnight. Overnight low temperatures will be in the 50s areawide. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... The aforementioned cold front stalled to our south, will lift through the forecast area on Sunday. This will bring noticeably warmer temperatures with highs in the 60s to low 70s throughout the area. Additionally, rain shower and thunderstorm chances will continue both Sunday and Monday. Thunderstorm chances will peak in the afternoon as instability increases with SPC having the forecast area in a general thunder risk each day. High temperatures will continue to warm on Monday due to southerly flow ushering warm air. High temperatures will be in the 70s to low 80s areawide. Those at highest elevations will stay in the upper 60s throughout the day. Overnight low temperatures will stay in the upper 50s to low 60s each night. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Conditions will remain active through the long term period. A potent shortwave trough and associated area of low pressure will track across the Upper Midwest toward the western Great Lakes on Tuesday, and then across southern Ontario/Quebec on Wednesday. A surge of warm/moist advection will ensue at low levels in response on Tuesday as a warm front lifts northward through the area. Afternoon showers and thunderstorms appear likely on Tuesday in response to the combination of daytime heating and low level warm/moist advection on the synoptic scale. High temperatures on Tuesday should reach into the upper 70s and lower 80s. Low-level forcing for ascent decreases somewhat on Wednesday as we move into the open warm sector and low-level flow turns westerly. Thunderstorms will be possible again Wednesday afternoon, but the coverage of storms should be considerably lower than Tuesday. In westerly low-level flow, a lee trough may serve as a potential focus for the development of storms. It will be noticeably warmer on Tuesday, with high temperatures expected to be in the mid-upper 80s. A prominent shortwave will eject eastward from the Plains toward the Ohio Valley/Great Lakes on Thursday. An associated area of low pressure will track toward the northern Ohio Valley toward PA and NY by Thursday evening. This system will act to increase large scale forcing for ascent across the area, while also strengthening the wind field through the low-mid levels. As a result, showers and thunderstorms are expected again Thursday, some of which may be strong to severe in nature. High temperatures on Thursday are forecast to reach into the upper 70s to mid 80s. Model solutions begin to diverge by Friday, with some models driving a cold front southeastward through the region Thursday night, while others hold off on the frontal passage until Friday night. As a result, a wide range of potential forecast outcomes exist. If we're post cold frontal on Friday, we'd have much cooler temperatures, and dry conditions. However, if the front remains upstream of the area, we'd have another day with warm and humid conditions, as well as additional chances for showers and thunderstorms. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... Onshore flow will bring reduced ceiling heights and plenty of cloudcover throughout the day today. MVFR to IFR conditions are expected throughout the day as a stalled frontal boundary continues rain and drizzle through the overnight. Winds remain out of the east with gusts staying 10-15 knots possible at all terminals except for CHO, where winds will remain lighter. Tonight, heavier precipitation rates may lead to sub-IFR conditions. Precipitation and thunderstorm chances continue Sunday with IFR flight conditions expected throughout the morning. Flight conditions possibly improve to MVFR Sunday afternoon, through dense fog and reduced CIGs could bring renewed chances for IFR/sub-IFR conditions. Winds shift to southeasterly on Sunday, blowing less than 10 knots. Unsettled conditions continue as we head into the week as a cold front approaches from the west. Prevailing VFR conditions are expected on Tuesday and Wednesday, but temporary drops to sub-VFR conditions may be possible in any thunderstorms. Winds will generally be out of the east on Tuesday, before turning out of the south Tuesday night into Wednesday. && .MARINE... A Small Craft Advisory remains in effect through tonight for the Chesapeake Bay with east winds blowing 10 to 20 knots. Gusts up to 25 knots are possible. Winds increase for the Upper Potomac and Upper Chesapeake Bay tonight, with SCA conditions expected. Showers and perhaps a thunderstorm are expected throughout the weekend as a warm front moves over the waters and a cold front approach from the west. Winds shift to southerly on Sunday and are expected to remain below SCA criteria as we head into the week. Sub-SCA level winds are expected in easterly flow on Tuesday, and then in southerly flow Tuesday night into Wednesday. SMWs may be possible either day if thunderstorms pass over the waters. && .TIDES/COASTAL FLOODING... Anomalies have started to rise in easterly flow overnight. Persistent easterly flow is expected through Saturday night, with winds turning south to southeasterly on Sunday. Tides are expected to remain elevated through the weekend, with Minor flooding possible in many locations. Moderate flooding may also be possible at Annapolis and Straits Point, where a Coastal Flood Watch is in effect for Saturday night. Water levels may begin to decrease during the day Monday as winds turn southwesterly && .LWX WATCHES/WARNINGS/ADVISORIES... DC...Coastal Flood Advisory until 8 AM EDT this morning for DCZ001. MD...Dense Fog Advisory until 8 AM EDT this morning for MDZ001-501. Coastal Flood Advisory until 5 PM EDT this afternoon for MDZ014. Coastal Flood Watch from late tonight through Sunday morning for MDZ014. Coastal Flood Advisory until 2 PM EDT this afternoon for MDZ017. Coastal Flood Watch from this evening through Sunday morning for MDZ017. VA...None. WV...None. MARINE...Small Craft Advisory until 6 AM EDT Sunday for ANZ530>534- 537>543. Small Craft Advisory from 6 PM this evening to 6 AM EDT Sunday for ANZ536. && $$ SYNOPSIS...AVS NEAR TERM...AVS SHORT TERM...AVS LONG TERM...KJP AVIATION...AVS/KJP MARINE...AVS/KJP TIDES/COASTAL FLOODING...KJP ####018007536#### FXUS61 KRLX 040759 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 359 AM EDT Sat May 4 2024 .SYNOPSIS... Upper level waves bring showers and storms at times through much of the weekend. Active weather continues into next week, with daily chances for showers and storms. && .NEAR TERM /THROUGH TONIGHT/... As of 315 AM Saturday... Scattered showers, and perhaps a thunderstorm or two, will continue to traverse the area early this morning, then activity is expected to continue throughout the day as a shortwave passes over the area. Coverage of showers and storms should peak during the afternoon and evening hours when instability will be the greatest. While storm activity may lessen again overnight, chances for showers are expected to linger through the end of the near term period. Precipitation amounts for today and tonight should be under an inch for much of the area, though pockets of higher amounts will be possible due to locally heavy rain in showers and storms today. Widespread flooding is not expected; however, some localized issues aren't out of the question in poor drainage areas or if higher amounts fall over locations that experienced heavy rain yesterday. Between cloud cover and precipitation, daytime temperatures are expected to max out in the 70s for the lowlands and mid 50s to low 70s along the mountains. Lows for tonight should then be in the 50s to mid 60s. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 400 AM Saturday... Key Points: * Isolated to scattered storms forming ahead of a cold front may grow to be strong to severe Sunday afternoon. * Heavy downpours remain a good possibility within showers and storms, leading to local flooding concerns. Episodic rounds of showers and thunderstorms remain entrenched within the short term period. For Sunday, continuing warm and humid conditions will receive support from an approaching cold front to sprout convection during the afternoon and evening timeframe. Storms are progged to form out ahead of the boundary, primarily in southeast Ohio, but as it outruns the front and enters a less unstable airmass east of the Ohio River, activity is expected to weaken. Might see a few instances of strong wind gusts where convection has the best chance of organization. Otherwise, will continue to monitor diminishing flash flood guidance as showers and storms glide over areas that have already received measurable rainfall the past few days. The cold front takes residency along the lower Ohio Valley late in the weekend into the start of the new work week. Up aloft, weak ridging becomes nudged off the Mid-Atlantic coast during the period as an upper level trough propagates through the Intermountain West. Previous model runs hinting at a brief reprieve in activity late Sunday night may still be onto something for early Monday morning as mainly diurnally driven activity wanes, but should return in earnest on Monday. Additional support from a southern stream system riding up along the stalled front will yield a south to north gradient of POPs, with the theme of afternoon convection prevailing once more. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 400 AM Saturday... Key Points: * Remaining active through the work week in response to waves of disturbances migrating in from the west. * Daily chances of showers and storms remain each day this week, with possibility of stronger storms arriving around midweek. * Increased chances of localized flooding as areas receive multiple rounds of rainfall. Unsettled weather continues to rule the roost through the work week as shortwave energy rides up along the stalled frontal boundary. Enough instability each day will support afternoon thunderstorm development, and initially remaining fairly diurnally driven that activity wanes during the overnight period. However, heading into midweek, a strong disturbance cycling over the Upper Midwest will drag in greater support under the guise of low level southwesterly flow inflicting increased moisture and temperatures. This would help to sustain convection further into the overnight period and may also assist in stronger convective trends during peak heating hours. QPF values through the course of the week will be heavily dependent on radar trends each day, with growing potential for localized flooding as soil conditions are tested with multi-day shower and storm chances. A cold front by the second half of the work week will attempt to cut off the daily warm and muggy weather. However, showers and perhaps thunderstorm develop remains intact for the weekend in response to additional shortwave support crossing over the area. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... As of 200 AM Saturday... Isolated to scattered showers continue to move across the area, bringing periodic restrictions to visibility early this morning. Additional CIG/VIS restrictions will be possible in low stratus and some areas of fog developing this morning. MVFR ceilings are expected to spread to most locations during the day as a passing disturbance brings more showers and storms across the area. A temporary improvement could occur this afternoon, then ceilings should lower again beyond 00Z. Visibilities will also continue to be impaired today into tonight during any heavier showers or storms. Calm to light and variable flow will persist through the early morning. Flow becomes southerly to southeasterly during the day, with light sustained winds and 15-20kt gusts possible along the mountains this afternoon. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY... FORECAST CONFIDENCE: Low to Medium. ALTERNATE SCENARIOS: Extent and intensity of restrictions due to fog or low stratus may vary from the forecast this morning. Timing of precipitation and associated restrictions may also vary. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE SAT 05/04/24 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H H H H H H H M H H H H HTS CONSISTENCY H H H H L M M H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY L L L L L L M M M M M M PKB CONSISTENCY H H H H H H H H H M M M CKB CONSISTENCY M M L M H H H H H M M M AFTER 06Z SUNDAY... IFR conditions possible in showers, stratus, and/or fog late Saturday night into Sunday morning. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...MEK/JLB NEAR TERM...JLB SHORT TERM...MEK LONG TERM...MEK AVIATION...JLB