Area Forecast Discussion
Issued by NWS Albany, NY

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258 FXUS61 KALY 261045 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 645 AM EDT Sun May 26 2024 .SYNOPSIS... Today will start out dry, with widely scattered showers and thunderstorms developing during the afternoon mainly south of Albany. A stronger low pressure system is expected to bring a widespread rainfall with localized downpours and breezy conditions Monday into Monday night. Chances for showers will linger through much of the week with an upper level trough remaining in place. && .NEAR TERM /THROUGH TONIGHT/... .UPDATE...No significant changes with this update. Just made some minor adjustments based on current obs. Temperatures are mild to start the day, with mid 50s to lower 60s. .PREV DISCUSSION[0345]...A disturbance will move east of the area by early this morning, with weak high pressure building in. Through much of today, upper level heights will be rising with short wave ridging developing. At the surface, a diffuse front will be in place across the southern part of the area. This boundary will be the focus for widely scattered showers and thunderstorms to develop during the afternoon given sufficient instability around 500-1500 J/Kg. This activity should be limited to areas in proximity to the front, which is from around Albany southward. While there may be a few stronger storms, the threat of severe storms still looks to be low, as forcing is weak and 0-6 km shear will be ~20-25 kt. Temperatures will be above normal, with highs mid/upper 70s in the mountains and lower/mid 80s in the valleys. It will feel more humid compared to the past few days for areas south of Albany, as dewpoints are expected to reach the lower 60s. Any showers/storms are expected to dissipate during the evening due to diurnal effects and limited forcing. Upper level ridge axis will progress eastward across the area through the night, which should keep conditions mostly dry. A large upper level trough and associated surface cyclone will start to approach from the Great Lakes late tonight, but forcing from a lead short wave should generally remain just to our west through daybreak. Just a few showers will be possible with thickening clouds. Lows will be mild with mainly upper 50s to lower 60s. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... Monday looks to be a somewhat active day with potential for downpours and breezy/gusty winds. The culprit is a deepening cyclone with MSLP anomalies increasing to -2 to -4 STDEV as it tracks from near the upper Great Lakes Mon morning to SE Ontario by Mon evening. Southerly winds will strengthen ahead of the cyclone, with 850 mb v- component(southerly) wind anomalies increasing to +2 to +4 STDEV. Gusts to around 30 mph are expected to develop. A few rounds of showers are possible during the morning, with better forcing arriving during the afternoon to evening associated with a disturbance aloft and an eastward advancing surface front. Will continue to mention likely/categorical PoPs during this time. While it will be moist/humid, we will likely not get into a true warm sector in eastern NY/western New England, so surface-based instability looks weak with only a few hundred J/Kg of CAPE. However, given strong wind field and deep layer shear, isolated strong winds gusts cannot be ruled out. This system is now within the hi-res model time window, with some indicating a narrow cold- frontal rain band(NCFRB) tracking eastward across our area. So there is the threat for localized downpours/heavy rainfall within convective lines as PWAT anomalies climb to +1 to +3 STDEV. This could lead to some urban/poor drainage flooding and isolated flash flooding. Generally 1.00-1.50" QPF is forecast with 2" in the S. Adirondacks and SE Catskills. However, locally higher amounts are possible within persistent downpours. There continues to be a Marginal Risk (level 1 of 4) of Excessive Rainfall from WPC for most of the area, with a small area of Slight Risk (level 2 of 4) in the SE Catskills. As the cyclone tracks into western Quebec Mon night, the occluded front will push eastward across our region through early Tue morning. Will mention the highest PoPs through around midnight, when tapering off from west to east overnight. Lows will be mild again ranging from mid 50s in the Adirondacks to lower/mid 60s in the Hudson Valley. With the surface front east of our area, it should be mainly dry on Tue. However, with upper level troughing and an additional weak disturbance moving through will mention isolated to scattered showers with a few T-storms possible. With no discernible change in air mass and more sunshine, highs will be quite warm ranging from upper 60s in the Adirondacks to lower 80s in the Hudson Valley. Another short wave will start to approach late Tue night, but doesn`t really get here until Wed, so will just mention slight/low chance PoPs for areas north/west of Albany. Lows will be cooler with mainly 50s expected. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... Upper level trough will be moving across the region on Wednesday. There are some differences in the models, as some guidance suggests the best upper level forcing will be passing by to the south of the region. Even so, there should be a good chance for showers over much of the area, especially during the afternoon and evening hours. Will have high chance to likely POPs over much of the region. With some minor amounts of instability present, will also mention the potential for some rumbles of thunder, especially southern areas, although there probably won`t be enough instability for any strong storms. With the clouds and precip, temps will generally be held down into the 60s to mid 70s. The upper level trough will remain over the region and may even become cutoff for Thursday into Friday. With some drier air moving in from the west, the chance for showers should decrease, but will still mention a slight chance for Thursday into Friday, mainly for eastern areas. Sky cover will gradually improve as well, with a partly sunny sky for Thursday and eventually a partly to mostly sunny sky by Friday. With the lower heights and cool temps aloft in place, highs will be below normal with 60s to low 70s for Thursday into Friday. Overnight lows will be cool in the 40s, but still not cold enough for any frost or freeze conditions. As an upper level ridge and warming temps aloft returns for the weekend, temps will return back to seasonable levels for Saturday, along with dry conditions and plenty of sunshine. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/...
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Flying conditions are VFR across the region. A slow moving frontal boundary is draped across southern parts of the area. With the front overhead, some sct-bkn clouds are in place, mainly around 5-10 kft. Winds are calm this morning and they are expected to remain fairly light through the day. It will probably remain VFR through the entire day, with some sct cumulus and passing mid level clouds. A stray shower or t-storm could develop late this afternoon or evening along the stalled boundary, but coverage looks very isolated, so won`t include in the TAF at this time. For tonight, flying conditions will start off VFR for all sites. The low level flow will switch out of the east to southeast, which will allow for more moisture to return to the region. Some MVFR stratus around 2-3 kft will develop by the late night hours for all sites, otherwise, no precip is expected. Outlook... Monday Night: High Operational Impact. Breezy. Definite SHRA...TSRA. Tuesday: Moderate Operational Impact. Chance of SHRA...TSRA. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Moderate Operational Impact. Likely SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday: Low Operational Impact. Breezy. Slight Chance of SHRA. Thursday Night: No Operational Impact. NO SIG WX. Friday: No Operational Impact. NO SIG WX.
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&& .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...JPV NEAR TERM...JPV SHORT TERM...JPV LONG TERM...Frugis AVIATION...Frugis