871 FXUS61 KALY 141834 AFDALYAREA FORECAST DISCUSSION National Weather Service Albany NY 234 PM EDT Sun Sep 14 2025
.SYNOPSIS... Highly isolated, light showers remain possible this afternoon as an upper-level disturbance rotates through the region. High pressure returns tonight, remaining in place and reinforcing regionwide dry conditions through at least Wednesday morning. A couple of disturbances then threaten to disturb tranquility by increasing chances for showers towards the end of the week but uncertainty keeps probabilities within the slight chance range.
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.DISCUSSION... As seen on latest water vapor imagery, the shortwave looming over the region since yesterday is continuing to shift eastward and beginning to depart. While dry conditions have persisted throughout the day today, courtesy of nearby surface high pressure and an antecedent dry airmass, light, highly isolated showers will be possible this afternoon mainly in the Upper- Hudson Valley, Helderbergs, lower Hudson Valley, and southern Litchfield County along a weak wind shift boundary associated with the trough aloft and surface trough/stationary boundary situated just to our south and east. Latest SPC Mesoanalysis page outlines weak instability in these areas courtesy of plenty of sunshine amid mainly clear to partly cloudy skies. In fact, the clouds in these areas are convective in nature, so a little forced ascent should be enough to reach saturation and produce at least a sprinkle. But as these isolated "showers" are dependent on daytime heating, any that develop will quickly cease upon its loss and wholly dry conditions will return by this evening. This will be aided further by the swift increase in geopotential heights aloft in the face of an eastward- building ridge and surface pressure increasing as a southeast- Canadian high slides south in the wake of the trough. Clearing skies will promote efficient radiative cooling conditions leading to patchy fog development especially in low-lying areas and allow low temperatures to drop into the low/mid 40s and low 50s.
With high pressure in place both at the surface and aloft, conditions will remain dry through at least Wednesday morning across all of eastern New York and western New England. Geopotential heights and temperatures aloft will average around +1 to +2 STDEV above normal throughout this time, according to the latest NAEFS, translating to above normal surface temperatures. Highs Monday, Tuesday, and Wednesday will subsequently be in the low/mid 70s to low 80s. Low temperatures Monday, similarly to tonight`s expectation, look to radiate down to the mid 40s to low 50s with fog development likely once again in valley areas. Lows Tuesday night and Wednesday night, however, will be a little more mild with upper 40s to upper 50s possible.
Similarly to previous forecast updates, there still remains uncertainty pertaining to the details of Wednesday and Thursday`s forecast, though generally speaking, there seems to be a consensus which keeps the previously discussed coastal low to our south at least through Wednesday morning. That said, the challenge remains whether or not it tracks far enough north Wednesday afternoon into Thursday morning to inflict light showers upon areas south and east of Albany. At this time, ensembles seem to favor a solution wherein light showers spread into the lower Mid-Hudson Valley and portions of southwest New England Wednesday afternoon and possibly lingering into early Thursday morning. However, given the still very dry airmass and overall weak forcing, should this solution become the reality, any rain that reaches the ground will be very light in nature and not contribute much in the way of accumulations beyond a few hundredths of an inch. For now, once again, we did not deviate from the 13z run of the NBM which painted slight chance to chance PoPs in the aforementioned areas Wednesday afternoon into Thursday. We will continue to monitor trends, though with guidance beginning to find agreement, confidence is increasing in this portion of the forecast. And, outside the chance for precipitation, Thursday`s highs will be in the mid 70s to low 80s with lows cooling primarily to the 50s overnight.
Friday should start off dry as the coastal low moves well off to our north and east and surface high pressure remains adjacent. However, chances for precipitation, though only slight, increase from northwest to southeast Friday morning as another shortwave trough and associated back-door cold front sink south and east towards the region. As we are unable to tap into a consistent moisture source though, the occurrence, let alone spatial extent of showers remains uncertain at this time. Therefore, maintained the NBM`s slight chance PoPs in the Southwest Adirondacks through Friday morning. But amid the uncertainty is one surety: Friday will be the final day of above-normal conditions over the next seven days as the cold front will allow temperatures to drop back towards normal. Friday`s highs will be in the upper 60s to low 80s with lows in the upper 30s to low 50s. Saturday will be dry with high pressure building back in across the region with temperatures in the low/mid 60s to low 70s. Lows Saturday night will then fall to the uper 30s to upper 40s.
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.AVIATION /18Z SUNDAY THROUGH FRIDAY/... Thru 18Z Mon...VFR conditions are forecasted prior to 06Z/Mon for KGFL/KALB/KPOU/KPSF with sct-bkn stratocumulus/cumulus and bkn mid or high level clouds, as an upper level disturbance moves through. A few light showers or sprinkles may impact the TAF sites and a VCSH group was used from 20Z/Sun to 00Z/Mon at KGFL/KALB/KPSF. The skies will clear thereafter with high pressure building in and some radiational mist/fog developing at the favored climo sites, such as KGFL/KPSF where IFR/LIFR conditions are possible 07Z-13Z/Mon. Expect VFR conditions to return thereafter with mostly sunny conditions. The winds will be northwest to northeast at 5-10 KT with a few gusts 15-20 KT at KPSF this pm. The winds will become light to calm tonight and be variable in direction at 5 KT or less in the late morning into the afternoon.
Outlook...
Monday Night: No Operational Impact. Patchy FG. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. 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.
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SYNOPSIS...Gant DISCUSSION...Gant AVIATION...Wasula
NWS ALY Office Area Forecast Discussion