Area Forecast Discussion
Issued by NWS Albany, NY
Issued by NWS Albany, NY
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858 FXUS61 KALY 221747 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 147 PM EDT Sat Jun 22 2024 .SYNOPSIS... It will remain warm and muggy through this evening with some showers and thunderstorms around. Any thunderstorm will be capable of producing gusty winds and heavy downpours. With the warm and humid air mass still in place, additional showers and thunderstorms are expected again on Sunday, with some of those storms potentially being severe. A few showers may linger into Monday, but cooler and less humid will briefly be returning to the region, before another warm and humid air mass returns towards the middle of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 147 PM EDT...A surface boundary is draped across central parts of the forecast area. North of this boundary, lots of cloud cover is in place, along with temps in the 60s to mid 70s dewpoints mainly in the 60s as well. South of the boundary, there are more breaks of sun, with temps well into the 80s and dewpoints around 70 F as well. This front has been fairly stationary and stalled through the day, but may start lifting northward as a warm front by later today. Right along the front, a batch of showers and embedded thunderstorms is heading eastward across the eastern Adirondacks, Lake George Saratoga Region, and southern Vermont. There is some showers and slightly more robust t-storm activity impacting the Mohawk and Schoharie Valleys, Helderbergs, Capital Region, northern Taconics and Berkshires. Even in these southern areas, the threat for severe weather is not very high at the moment, but small hail, wind gusts up to 40 mph, cloud- to- ground lightning and downpours capable of producing ponding in urban and poor drainage areas looks to occur. This activity should be clearing off to the east of our area by the mid to late afternoon hours. Additional showers and storms are expected to develop with daytime heating for areas in the warm sector to the south of the boundary for late today. CAPE values increase to 1000-1500 J/kg for areas south of the frontal boundary. Shear isn`t very impressive, but is slightly higher than the past few days at 25 to perhaps 30 kt for the 0-6 km layer. With a similar environment to that of the past few days, most storms will probably be of the pulse- variety, but the increased shear may help to form some loosely organized clusters as cold pools congeal. A couple of strong to severe storms are possible, with the primary threat being damaging winds as low- level lapse rates should be steep once again. North of the warm front, instability will be lower, so while there could be a few rumbles of thunder the probability for severe weather is lower. Accordingly, SPC has a marginal risk for severe weather today for areas mainly along and south of I-90. Any storms today could produce locally heavy rain with PWATs remaining at 1.6 to 1.9" and cloud depths of 10-12 kft. With flow parallel to the low-level boundary, some training and/or backbuilding of storms is possible, especially with slow MBE vectors. WPC has placed much of our region in a marginal risk for excessive rainfall leading to flash flooding, which seems appropriate given scattered nature of storms this afternoon. Today will remain quite hot for areas south of the warm front where highs will climb well into the 80s to low 90s. Areas north of the warm front will remain slightly cooler with high terrain areas topping out in the 70s with 80s for the valleys. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... **Heat Advisory for the mid-Hudson Valley and Litchfield County, CT through 8PM Sunday.** Convection should die off after sunset with the loss of diurnal heating. However, for areas from the ADKs through southern VT, some lingering showers will remain possible overnight in the vicinity of the warm front as it continues to lift northwards. Some embedded rumbles of thunder are also possible with showalter values of 0 to -2. It will remain quite warm and muggy, with lows in the mid and upper 60s to low 70s. Patchy fog and low stratus will once again be possible, especially for areas that receive rain during the day today. Sunday is shaping up to be an active weather day. A potent upper shortwave and associated surface cyclone track from the Great Lakes along the international border, with the surface low deepening to around 995 mb. The warm front lifts to our north, putting our entire region in the warm sector. A pre-frontal trough will track across the region during the afternoon, ahead of the main cold front which tracks through Sunday night. Multiple rounds of showers and storms, some strong to severe, are expected Sunday afternoon and evening... Despite mostly cloudy skies, CAMs suggest that we will see SBCAPE values increase to 1500 to potentially 2000 J/kg. Shear looks more impressive, with guidance suggesting around 30 to 35 kt winds from the southwest at 850 mb and over 40 kt winds from the west/southwest at 500 mb. Hodographs therefore lengthen with some low-level curvature. Now, there are questions as to just how much we destabilize given the expected cloud cover, and the forcing does not look overly impressive until the cold front comes through Sunday night. Nevertheless, given the overlap of shear and expected instability, we collaborated with SPC to introduce a slight risk across the region Sunday, as any storms that do develop in the warm sector could quickly become severe. Main threat is damaging wind gusts, but isolated instances of large hail or even a tornado can`t be ruled out given the more impressive shear. All storms will be capable of producing frequent lightning and heavy rain, but faster storms motions should limit the flash flood threat. Sunday will be quite warm and muggy, and if forecast confidence increases the heat advisory may need to be expanded further north up the Hudson Valley to around the Capital District. There will likely be lingering showers and storms into Sunday evening, but the severe threat diminishes with the loss of daytime heating and waning instability. It remains warm and muggy with some patchy fog ahead of the cold front, as the front may take until 9-12z to fully clear our area and track into central New England. However, cooler temperatures and lower humidity are expected behind the front on Monday. We will likely still have some showers around as the upper trough and associated cold pool aloft move overhead, but we are not expecting severe weather or additional hydro concerns. Showers diminish Monday night as surface high pressure builds in from the southwest. Monday night temps drop into the mid to upper 50s for most areas. && .LONG TERM /TUESDAY THROUGH FRIDAY/... The extended forecast period opens with a brief period of fair and dry weather with high pressure building in from the Ohio Valley, then shifting eastward over the Mid Atlantic States. The flow aloft will be west/northwest. Temps will run above normal but humidity levels should not be too bad with dewpoints in the 50s to around 60F. Highs will be in the mid and upper 80s in the lower elevations and 70s to lower 80s over the higher terrain. The sfc anticyclone moves offshore with a return flow of more humid air beginning. A warm front will bring a slight chance of showers or an isolated thunderstorm over the western Adirondacks. Lows will be in the upper 50s to mid 60s. Wed-Wed night will be the most unsettled day in the long term. A prefrontal sfc trough and a cold front will bring numerous showers and a chance of thunderstorms. Depending on the amount of instability and sfc heating, some of the storms may be on the stronger side. PWATs surge above normal by a couple standard deviations based on the latest NAEFS. Locally heavy rain will be possible. Max temps will range from the mid 80s to lower 90s in the valley areas with the best chance of lower 90s in the mid Hudson Valley with 70s to lower/mid 80s over the hills and mtns. The showers and thunderstorms should be diminishing by Thu morning. Lows will be in the 50s and lower 60s north and west of the the Capital Region and mid and upper 60s to the south and east. Thursday through Friday...A few showers are possible with the upper trough passage and in the wake of the cold front. A cooler and drier air mass will be ridging in during the afternoon from the Great Lakes Region. Temps will be near seasonal levels with upper 70s to lower 80s below 1000 ft in elevation and 60s to mid 70s above it on Thu. Temps and humidity levels will be pleasant Thu night with 50s and even some 40s over the Adirondack Park. Zonal flow sets up aloft to close the week with the anticyclone moving over New England. Fair conditions continue with seasonable temps. CPC is predicting temperatures above normal for Days 8-14 (June 29th to July 5th) with precipitation near to slightly above normal for eastern NY and western New England. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... Showers and t-storms have been impacting KGFL and KALB already early this afternoon and will be impacting KPSF shortly. Most of the activity is far enough north to avoid KPOU at this time, but some scattered activity is possible there later today into this evening. Within t-storms, flying conditions have lowered to IFR due to heavy rainfall. Winds have not been very gusty in thunderstorm activity today, so the main threat seemed to be low visibility for a brief time (mainly 30 minutes or so). Northerly winds will be light and variable this afternoon but may start to switch to the south soon. Showers and thunderstorms will be winding down by later this evening. The recent rainfall and high low level moisture will lead to the development of fog and low stratus at all sites, resulting in MVFR/IFR conditions for the late night hours (especially for ceilings). These low clouds and fog will start to dissipate shortly after daybreak, allowing for VFR conditions to return with just some sct-bkn lower clouds. South to southwest winds will be around 5 kts overnight. The threat for additional showers and thunderstorms will return on Sunday afternoon for all sites. Will just address with VCSH for now until we get more confidence regarding timing and coverage. Outside of t-storms, flying conditions should be VFR with southerly winds around 10 kts. Outlook... Sunday Night: Moderate Operational Impact. Likely SHRA...TSRA. Monday: Moderate Operational Impact. Chance of SHRA...TSRA. Monday Night: Low Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Moderate Operational Impact. Chance of SHRA...TSRA. Wednesday Night: Moderate Operational Impact. Likely SHRA...TSRA. Thursday: Low Operational Impact. Slight Chance of SHRA. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...Heat Advisory until 8 PM EDT Sunday for CTZ001-013. NY...Heat Advisory until 8 PM EDT Sunday for NYZ064>066. MA...None. VT...None. && $$ SYNOPSIS...Frugis NEAR TERM...Frugis/Main SHORT TERM...Main LONG TERM...Wasula AVIATION...Frugis