####018005838#### FXUS61 KBTV 030850 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 450 AM EDT Fri May 3 2024 .SYNOPSIS... Dry weather persists through Saturday, except over northern New York where a few light rain showers are possible on Saturday. Temperatures will be mild, with highs in the 60s and low 70s. Widespread rainfall returns for the day on Sunday before dry conditions return to start next week. Conditions mid week through Friday are trending wetter with daily chances of rain. && .NEAR TERM /THROUGH SATURDAY/... As of 417 AM EDT Friday...The region is currently between a shortwave trough digging south over the Atlantic and a ridge building in from the west. Low clouds are lingering from weak northeasterly flow and trapped low-level moisture, and they should persist for the rest of the night. Fog has developed in a few of the sheltered valleys where clearing has occurred, particularly where it rained yesterday. Due to the cloud cover and some light winds, temperatures should not fall much more tonight, so lows will generally be in the 40s. The ridge will build in during the day today and it will initially clear out the lingering low clouds and fog. Combined with warm advection from increasing southerly flow, temperatures will rise into the upper 60s and low 70s, with the highest temperatures expected in the St. Lawrence Valley. The sun will be short lived as high clouds ahead of an occluded front will spread into the region not long after the low clouds depart, so much of the sun will likely be filtered. The front will be able to spread a few showers into northern New York tonight, but it will be weakly forced and falling apart as it arrives, so precipitation amounts should be under a tenth of an inch. High pressure situated over Atlantic Canada will be stubborn and prevent the rain from reaching Vermont. The high remains in place for Saturday and the day should be be mostly dry, even over New York, where at most there will be a couple light showers. The high clouds should remain in place but an absence of lower clouds should allow temperatures to rise into the 60s across the region. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/... As of 417 AM EDT Friday...Ensemble and deterministic models have trended much drier Saturday night keeping the highly amplified ridge axis over the North Country. This will delay the onset of precipitation while flow aloft continues to stream ample moisture northward. As such, QPF was cut from the overnight hours with only a few hundredths possible over northern New York and nothing for Vermont. Temperatures will remain mild in the 40s to low 50s. Frontal passage is still expected through Sunday, moving quickly west to east as ridging shifts eastward. Total QPF should be less than 0.5" with general amounts ranging from 0.05-0.33". Highest amounts will be across the Greens of southern Vermont with amounts decreasing northward. Temperatures will be seasonal in the mid/upper 50s to low 60s. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... As of 417 AM EDT Friday...Post frontal thermal advection will be near neutral given the replacing airmass will originate over the central Plains. As ridge amplifies Monday/Tuesday, dry conditions will prevail with temperatures warming above seasonal averages into the upper 60s to low 70s. The next wave continues to be projected to move into the North Country Tuesday night through Wednesday night possibly bringing another round of elevated PWATs, decent instability, and some thunderstorm chances. Instability trends have decreased from previous model runs, but will continue to monitor for potential of stronger cells. For late week, guidance has trended wetter with mean longwave troughing stagnating between the Great Lakes region and the North Country. This pattern would favor active weather and possibly keeping daily rain chances through the end of the week. With fast flow aloft, any troughs moving through will be moving quickly. Temperatures are expected to remain around seasonal averages with colder air locked well north. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... Through 12Z Friday...Ceilings have been gradually lowering this evening and should continue to do so overnight. Confidence is relatively high that ceilings will reach IFR at BTV while confidence is lower whether ceilings will reach IFR at PBG and MPV. EFK and SLK should hold onto their low clouds and fog overnight before it scours out after daybreak. However, the IFR cloud deck at SLK could briefly scatter out a couple times overnight. The IFR ceilings at RUT are expected to remain the entire night but there is lower confidence there. Ceilings will rise quickly after daybreak and all terminals should be VFR by late morning. There should only be high clouds during the day today but the clouds will begin to lower and thicken tonight, though they should remain VFR for the first part of the night. Winds are relatively light and are generally northerly but they should transition to southerly during the day tomorrow. LLWS is not a concern. Outlook... Saturday: VFR. Chance SHRA. Saturday Night: VFR. Chance SHRA. Sunday: Mainly VFR, with areas MVFR possible. Likely SHRA. Sunday Night: MVFR/IFR conditions possible. Chance SHRA. Monday: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Myskowski NEAR TERM...Myskowski SHORT TERM...Boyd LONG TERM...Boyd AVIATION...Myskowski ####018006334#### FXUS63 KGRB 030853 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 353 AM CDT Fri May 3 2024 Forecast discussion for routine morning forecast issuance .KEY MESSAGES... - Scattered showers and isolated thunderstorms are possible Saturday into Saturday evening with more showers and thunderstorms Monday night through Wednesday. - Slightly elevated fire weather conditions, mainly across northern WI, this afternoon and again Sunday and Monday afternoons due to RHs dropping into the 20-35 percent range. - A few rivers will remain at or reach bankfull stage into the weekend. && .DISCUSSION... Issued at 352 AM CDT Fri May 3 2024 Short Term...Today...Tonight...and Saturday Main forecast issues will be dealing with lingering low clouds/fog early today, relative humidities in the 20/30s this afternoon and any fire weather issues, and shower/thunder chances Saturday afternoon. Today...rain showers associated with a shortwave trough and weak low pressure/front will exit east of the area early this morning, with only some patchy fog/drizzle/sprinkles left around sunrise across mainly northern/eastern WI. As drier air advects in from the west, look for any light precip to end/exit, with the fog and low clouds mixing out through the morning hours. Plenty of sunshine is expected in the late morning and afternoon as high pressure builds across the western Great Lakes. Mixing to at least 4000-5000 ft will support warmer temperatures, with highs climbing into the upper 60s to middle 70s, and west winds gusting to 20 to 30 mph (strongest in northern WI) and low relative humidity (20-35 percent) in the sandy soil areas. If we can mix closer to 7000 ft, as the RAP suggests, wind gusts would be a little higher and RH's a little lower. The recent rainfall, along with the continued green-up, will limit the overall fire weather concern. However, locations across northern WI may see slightly elevated fire weather conditions as green-up has been the slowest, the deepest mixing is expected and winds will be the highest this afternoon. Tonight...dry conditions continue as high pressure slides east of the region. Mostly clear skies are expected during the evening, with mid and high clouds spreading east across the area overnight. Lows look to mainly be in the 40s with a light south/southeast wind. Saturday...a dry start to the day is expected, but skies look to become cloudy through the morning. An area of rain showers will spread west to east across the area during the morning, as another shortwave trough and frontal boundary approach from the west. This first area looks to be weakening as it traverses the area, but additional showers look to develop later in the morning and afternoon ahead of the front. Rain amounts look to remain under a quarter inch for most spots. As for thunder chances, assuming the front pushes through in the afternoon, should get at least 500 J/kg of CAPE across eastern WI by early-mid afternoon. This would be enough to support a few storms, but severe weather is not expected. Will carry a slight chance for thunder in the afternoon across parts of central and eastern WI. Light south/southeast winds will increase in the morning ahead of the front, then shift to the west/northwest behind the front in the afternoon. Winds could get a little gusty, up to around 35 mph ahead of the front, but will be difficult to break into the inversion to mix down the stronger winds. Will hold gusts closer to 20-25 mph for now. As CAA arrives behind the front, better mixing will promote gusts to ~25 mph. Long Term...Saturday Night Through Thursday Main focus of the extended period revolves around a well organized cyclone that is forecast to bring showers and thunderstorms to the region early to middle of next week. Scattered showers and an isolated thunderstorm or two may linger Saturday night into early Sunday morning across far eastern WI as an upper-level trough and surface cold front depart from the region. A ridge of high pressure is forecast to build over area Sunday returning dry and calm conditions to the region through at least Monday afternoon. The ridge will also ushering in a drier air mass which may lower RHs to around 30 percent Sunday and Monday afternoons. These lower RHs and warmer temperatures in the low 60s to around 70 degrees may bring slightly elevated fire weather conditions to far northern WI, where vegetation has yet to green up, Sunday and Monday afternoons. While there are still slight differences in timing and intensity, ensemble models are in decent agreement that a near vertically stacked low pressure system will eject out of the Great Basin toward the norther Plains late Monday into Tuesday. An initial wave of warm air advection out in front of the low along with diffluent flow aloft may bring a round scatter showers and storms Monday night into Tuesday. Perhaps the best chance for strong to potential severe storms comes Tuesday afternoon and evening as much of the CWA may reside in the warm sector allowing for an increase in instability, however, the question remains if there will be a forcing mechanism present for thunderstorm initiation. Periods of rain and thunderstorms will remain possible through Wednesday and Thursday as the cyclone brings several pieces of jet energy across the region. With several area rivers and streams already at or near bankfull the active pattern for next week may create some minor flooding concerns particularly in low laying and flood prone areas. && .AVIATION...for 06Z TAF Issuance Issued at 1028 PM CDT Thu May 2 2024 IFR ceilings are expected west of a IMT to DLL line overnight, with MVFR ceilings and scattered showers to the east. Skies will clear rapidly Friday morning as a surface front moves across the area. Once the skies clear Friday morning, good flying weather is expected through at least Friday night. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Bersch/GK AVIATION.......RDM