Area Forecast Discussion
Issued by NWS Albany, NY
Issued by NWS Albany, NY
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422 FXUS61 KALY 250529 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 129 AM EDT Wed Sep 25 2024 .SYNOPSIS... The two week stretch of dry conditions over much of eastern New York and western New England will not be allowed to extend past this evening as showers look to spread into the region from northwest to southeast overnight tonight. But unsettled conditions will be short lived as yet another period of dry weather looks to begin Friday into the upcoming weekend. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... .UPDATE...As of 129 AM EDT, warm advection rain showers continuing to move through the Adirondacks and upper Hudson Valley. Made minor adjustments to pop and wx grids to account for latest radar trends. Otherwise, fcst in good shape. .UPDATE...As of 0955 PM EDT, we`re beginning to see rain showers moving into portions of Herkimer and Hamilton counties as a band of WAA builds into central New York. Rainfall amounts across that area have ranged from a few hundredths to near a quarter of an inch (mainly in persistent bands of showers). Latest CAMs including the HRRR have been handling the evolution of showers well, so have updated POPs to reflect obs and newer guidance over the next few hours. Previous discussion below... .PREV DISCUSSION [0400 PM EDT]...Tranquility persists this afternoon as part of the last day of the recent two-week stretch of dry conditions across much of eastern New York and western New England. Visible satellite imagery shows mostly to partly sunny skies across the region with the most consistent coverage south and east of Albany courtesy of easterly flow driving coastal clouds inland. And though a cirrus shield has reached the western edge of our CWA in advance of a low pressure system currently situated in the Ohio Valley, a hole or minimum in cloud coverage has existed for much of the afternoon from Albany northward due to enhanced subsidence and possible downsloping effects with high pressure adjacent to the northeast. Throughout the remainder of the afternoon/evening and into the overnight, the high over Atlantic Canada will gradually slide south and east as upper- level ridging aloft is forced to deamplify and also shift south and east as an upper level trough digs into the Mississippi Valley. By tomorrow morning, the trough looks to split as the southern portion deepens and closes off into an upper-level cutoff low in the Mississippi Valley and the northern portion remains a positively-tilted shortwave about the base of an upper low in northern Canada. The aforementioned surface low currently in the Ohio Valley will gradually track north and east into the northeast Great Lakes/southeast Ontario as the axis of the shortwave aloft digs farther south into the same area. Warm air advection ahead of the attendant warm front associated with the low paired with favored synoptic-scale forcing for ascent at the leading edge of the shortwave will allow showers to develop and track into the region by tonight. Showers will spread into the region more or less from west to east, bringing the initial accumulations of what will be much of the region`s first accumulating rainfall in over 14 days. Showers tonight will be relatively light in nature, impacting areas mainly north and west of Albany. Extensive cloud cover as a result of the advancing system will make for more mild temperatures in comparison to last night with upper 40s to low 50s anticipated. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... Showers continue into the day Wednesday as the shortwave propagates farther eastward and the surface low continues its progress northward whilst the cutoff low sinks farther into the deep south. Southwesterly flow across the area will align with the southwest to northeast axis of moisture extending northeastward from the Gulf of Mexico, bringing plenty of fuel to sustain rounds of showers throughout the day and into Wednesday night. The heavier showers look to come Wednesday evening into Thursday morning as upper-level flow increases in response to the deepening and closing off of the upper wave into an upper low. Increased divergence aloft and upslope flow could lead to some heavier downpours in higher terrain regions of the Southwest Adirondacks and Southern Greens, but with the recent rain deficit, there are no hydro concerns at this time. It is also possible that some embedded thunderstorms develop Wednesday afternoon/evening as latest CAMs are indicating some elevated instability within the environment. However, no severe weather is anticipated. Showers continue into Thursday morning as a weak cold front swings through the region, but gradually begin to wane in spatial coverage as the upper low moves east into southeast Quebec, taking with it the better forcing. By Thursday night, primarily dry conditions will be reinforced across the region as heights increase in the wake of the upper low with high pressure ridging building over the Midwest and into Ontario. High temperatures Wednesday will be the cooler of the period with extensive cloud cover and rain-cooled air, reaching only the mid 50s to mid 60s. Low temperatures Wednesday night will only dip into the low to mid 50s with pockets of upper 40s above 1500 ft and upper 50s in valley areas. Highs then warm Thursday to the mid/upper 60s to low 70s with pockets of low 60s across higher terrain regions. Thursday night will feature lows in the low to upper 50s with upper 40s in the Southwest Adirondacks and highest peaks of the Eastern Catskills and Southern Greens. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Another prolonged period of dry weather is anticipated across the long term forecast period as upper-level ridging builds in across the region Friday into Saturday and remains in place through early next week as an Omega block sets up Monday into Tuesday. Though the closed low in the Deep South will track north through the Mississippi Valley through the weekend, the high pressure ridging it encounters will keep it at bay, leading to little to no impact for our region. High temperatures will be fairly similar throughout the period with mid/upper 60s to low 70s across much of the region outside of pockets of low 60s possible across higher terrain. Low temperatures will generally fall to the upper 40s to low 50s each night of the period. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... Through 06Z Wednesday...Mixed VFR/MVFR flying conditions ongoing as rain showers track into the region from the west. MVFR vsbys within showers are expected at all terminals by 08-10Z Tue, with cigs trending downward slightly, but remaining VFR/MVFR. A break in shower activity later this morning will see renewed VFR vsbys, which will continue through the early afternoon. A second batch of rain showers after 18-20Z Tue will yield MVFR cigs/vsbys at all terminals, with cigs/vsbys trending downward possibly to IFR after 00Z Wed. East to southeast winds at ALB/POU/PSF at 5-10 kt will continue through much of the period, becoming southeast to south after 18-20Z Tue. At GFL, calm winds through the remainder of the overnight period will give way to southeast winds at 5-10 kt after 12-15Z Tue. Outlook... Thursday Night: Moderate Operational Impact. Chance of SHRA. Friday: No Operational Impact. NO SIG WX. Friday Night: No Operational Impact. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: No Operational Impact. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: No Operational Impact. NO SIG WX. && .CLIMATE... Having last recorded measurable precipitation on September 9, the dry spell in Albany reached 14 days on Monday, September 23. This is the first two-week dry spell in Albany since May 11-25, 2021, when a trace of precipitation was observed over 15 days. Furthermore, every day in the current dry spell has seen zero precipitation, marking the first absolute dry spell of at least 14 days since October 4-26, 1963. Tuesday, September 24 is expected to extend the dry spell to 15 days before widespread rain ends the streak on Wednesday. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Gant NEAR TERM...Gant/Speck SHORT TERM...Gant LONG TERM...Gant AVIATION...Picard CLIMATE...Picard