Area Forecast Discussion
Issued by NWS Albany, NY
Issued by NWS Albany, NY
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195 FXUS61 KALY 252328 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 728 PM EDT Wed Sep 25 2024 .SYNOPSIS... A couple of much needed wet days will give way to dry conditions for the end of the workweek and weekend with seasonable temperatures. The next stretch of dry weather will be much shorter than this last spell with shower chances increasing again Tuesday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Area of rain over the region with the best coverage along and north of I-90 but scattered showers are also south of I-90. There have been a few rumbles of thunder in the embedded heavier elements in the western Mohawk Valley and southern Adirondacks. The back edge is about to enter the western Mohawk Valley and southwestern Adirondacks but will feed back in later tonight. More rain will also develop in southern areas and all areas will see measurable rain tonight with the most, again, along and north of I-90 to southern VT, some locally heavy by daybreak. Just minor adjustments to temperatures, rain chances and sky cover through the night. PREVIOUS DISCUSSION: Moisture surges into the region from the south and west as part of a fetch extending north and east from the Gulf embedded within the southwest flow of the leading edge of a mid to upper- level trough whose axis has dug deep into the Mississippi Valley. A surface low pressure system has become situated in southeast Ontario, extending a warm front south into the Ohio Valley just west of the western border of New York State with a northern stream shortwave overhead. Additional rounds of showers, already underway for portions of the Eastern Catskills; western Mohawk Valley; and Mid-Hudson Valley, are therefore anticipated into tonight as upper-level divergence increases with the southeastward track and intensification of the upper- level shortwave and surface convergence and warm air advection increases ahead of the warm front. Shower coverage will continue to increase from southwest to northeast through the overnight, becoming widespread with embedded heavier downpours in regions of higher terrain where orographic effects will enhance lift. However, some heavier showers will be possible in the Mohawk and Upper- Hudson Valley/Capital District as well given the moist environment and favorable synoptic environment. Low temperatures will remain on the mild side with extensive cloud cover inhibiting radiational cooling. Temperatures will only fall to the low to upper 50s with pockets of upper 40s possible above 1500 ft. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... By tomorrow morning, the aforementioned shortwave looks to deepen such that it closes off into an upper-level low just south of the James Bay. Additional moderate showers are possible given the intensification and subsequent enhancement of divergence aloft. Likewise, with the surface low tracking north and east into western Quebec, the warm front will swiftly track through the region throughout the day followed in close succession by a weak cold front whose forcing could also contribute to some additional moderate to locally heavy downpours tomorrow morning into early tomorrow afternoon. Despite the expectation for moderate to heavy rainfall at times, there are no concerns of river or flash flooding given the recent dry spell. Latest CAMs indicate a line of potential convection developing tomorrow afternoon and tracking through the Capital District south and east into tomorrow evening with the aforementioned cold front. With extensive cloud cover, it is likely that there will not be sufficient instability to generate widespread thunderstorms along and ahead of the front. However, with cooler temperatures aloft and some very modest instability (generally less than 500 J/kg), it is possible that some rumbles develop within the line of showers. Included slight chance of thunder south and east of Albany to account for this possibility. High temperatures tomorrow will range from the mid 60s to low 70s with pockets of low 60s across regions of higher terrain. The closed low, with fast flow aloft, will track quickly east toward southeast Quebec, forcing the quick track of the cold front through the region. By tomorrow evening, the cold front looks to have completed its track through the region with dry conditions following close behind. In fact, much of the overnight period tomorrow night appears to be dry. Low temperatures will be a few degrees cooler than the previous night with upper 40s to mid 50s anticipated across much of the region. Some isolated spots of upper 50s are possible within the lower Mid-Hudson Valley and southern Litchfield County. Dry conditions will then be maintained Friday into Saturday as heights increase with upper-level ridging building in from the west. Surface high pressure, in tandem, will nose in from the southwest and remain in place through the remainder of the short term period. High temperatures Friday and Saturday will largely range from the upper 60s to low 70s with pockets of mid 60s across higher terrain regions. Low temperatures Friday night will range from the upper 40s to low 50s. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Upper low and associated cold front will exit Friday night, and some clouds and a lingering isolated shower are expected in the mid Hudson Valley and NW CT. By Saturday more of a slow clearing and drying trend with intervals of clouds and sun. Highs Saturday around 70 to mid 70s with some upper 60s in higher elevations. Upper ridging gradually builds in from the west Sunday through Monday. Partly to mostly sunny with highs Sunday around 70 to mid 70s and 60s higher elevations. Highs Monday in the lower to mid 70s with around 70 higher terrain. Northern stream energy approaches and drops out of Canada along with an associated warm advection ahead of it Tuesday night. Isolated showers by Tuesday afternoon and evening, then increasing coverage of showers through Wednesday with the approaching cold front. Highs Tuesday in the upper 60s to lower 70s and mid 60s higher terrain. Highs Wednesday in the mid to upper 60s with mid 50s to lower 60s higher elevations. && .AVIATION /23Z WEDNESDAY THROUGH MONDAY/... Area of rain with VFR visibilities and mainly MVFR ceilings will continue through this evening. Rain coverage and intensity will increase by about 06Z-09Z, when ceilings will drop to IFR at all TAF sites and visibilities will straddle MVFR/IFR with periods of moderate rain. The rain should become lighter by about 16Z-17Z at KALB and KGFL, but visibilities and ceilings will probably stay IFR through the morning and afternoon ad KPOU and KPSF as a cold front slowly drops south. The winds will be east to southeast at less 7 Kt from the south to southeast tonight. Winds at around 2000 feet will increase to 35-40 KT from the south toward 06Z. Low Level wind shear was added to KGFL/KPSF/KPOU until about 16Z. We may need to add KALB with later TAF issuances. The winds will be southerly at 5-10 KT in late Thursday morning into the afternoon. Outlook... Thursday Night: Moderate Operational Impact. Chance of SHRA. Friday to Monday: No Operational Impact. NO SIG WX. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Gant NEAR TERM...Gant/NAS SHORT TERM...Gant LONG TERM...NAS AVIATION...NAS