Area Forecast Discussion
Issued by NWS Albany, NY
Issued by NWS Albany, NY
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211 FXUS61 KALY 220810 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 410 AM EDT Sat Jun 22 2024 .SYNOPSIS... Warm and humid weather continues today and tomorrow, with a chance for showers and thunderstorms both days. Some thunderstorms Sunday could be strong to severe. We briefly cool off Monday behind a cold frontal passage, but then warm back up Tuesday and Wednesday with a chance for additional showers and storms mid to late week with another cold front. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... **Heat Advisory for the mid-Hudson Valley and Litchfield County, CT through 8PM Sunday.** As of 4:10 AM EDT...Our region remains under zonal flow aloft with a stalled frontal boundary draped across/just north of our cwa. Most areas are dry right now, although a few showers have popped up to our west in association with the first in a series of several upper impulses that will track along the frontal boundary today and tonight. These showers will likely move into our region over the next few hours, but should remain isolated to scattered in nature and will remain mainly north of I-90 through early this morning. Otherwise, the rest of the night will remain warm and muggy. With abundant low-level moisture, we are seeing quite a bit of patchy fog and low stratus around. Fog and low stratus should mix by mid-morning. We remain under zonal flow aloft atop the upper ridge, and multiple upper impulses will be riding along the boundary as it lifts back north wards as a warm front. Northern areas will likely see greater coverage of showers with embedded rumbles of thunder through the morning, with drier conditions south of I-90. However additional showers and storms are expected to develop with daytime heating for areas in the warm sector. CAPE values increase to 1000-1500 J/kg for areas south of the warm front. 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 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 /08Z SATURDAY THROUGH WEDNESDAY/... Through 06Z Sunday...A frontal boundary will become stationary over eastern NY and western New England this morning. Multiple disturbances will move along the boundary in the late morning through the afternoon producing scattered showers and thunderstorms, as it slowly lifts northward into tonight. Widespread MVFR/IFR cigs and some VFR/MVFR vsbys are impacting KALB/KGFL/KPOU/KPSF this morning. Some light showers are near KGFL with MVFR cigs. We are expecting IFR/LIFR conditions to develop between 06Z-09Z/SAT and continue to 12Z-13Z/SAT. KALB has IFR cigs at 900 ft AGL...and is hovering near MVFR bottom range. KPSF is also there. We expected IFR cigs and some MVFR/IFR vsbys to form due to recently wet ground and abundant low-level moisture. KPOU has cleared with some mid and high clouds. They will likely see IFR/LIFR mist/fog form with IFR/MVFR cigs. We have tried to trend due with TEMPO groups. The conditions will briefly improve to MVFR/VFR in the late morning into the early pm, but showers and thunderstorms will form ahead of the frontal boundary with weak waves moving along it. We used PROB30 groups to bring showers/thunderstorms in between 16Z-22Z/23Z from north to south. Conditions will lower to MVFR and spotty IFR in the showers/storms. There is a secondary wave of showers/thunderstorms in the 00Z-06Z/SUN time frame that may occur that we placed PROB30 groups in for KALB and prevailing showers for KGFL. We were less confident for KPSF/KPOU and left just VCSH MVFR cigs. The winds will be light/variable to calm this morning. They will be southeast to south at less than 7 KT late this morning into the afternoon and will become light to calm tonight. Winds will be stronger, and variable in direction in and near any thunderstorms. 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...Main NEAR TERM...Main SHORT TERM...Main LONG TERM...Wasula AVIATION...Wasula