![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
Area Forecast Discussion
Issued by NWS Albany, NY
Issued by NWS Albany, NY
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
908 FXUS61 KALY 160226 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 1026 PM EDT Thu Aug 15 2024 .SYNOPSIS... High pressure builds the region overnight through Friday, giving us a warmer, mainly dry and more humid end to the work. Conditions turn cloudy and remain muggy this weekend into early next week as a slow moving disturbance approaches with chances for rain increasing through the day Saturday before higher chances for rain, potentially steady at times, arrive Sunday through early next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 1025 pm EDT...A surface trough is moving across northern and western New England, as the mid and upper level trough is lifting north of Nova Scotia and New Brunswick. The isolated showers/thunderstorms have diminished with the loss of the diurnal heating. A few thunderstorms became severe over Saratoga and Washington Counties with 1-1.75" hail and some spotty wind damage. These storms were loosely organized slow movers. The skies continue clear prior to midnight with patchy fog developing already near KGFL. The mainly clear skies (outside smoke and high clouds) and light to calm winds will promote radiational cooling. The mist/fog will be mainly below in the valleys, as high pressure builds in. Lows will be mainly in the mid 50s to lower 60s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... High pressure building southward from southern Canada becomes established across the Northeast tomorrow as upper level ridging from western NY builds eastward. This will support mainly dry conditions with morning sun once again mixing with some fair weather cumulus. CAMs continue to suggest a few isolated showers/storms may develop along the spine of the southern Greens so included slight chance POPs but subsidence in the wake of the exiting low in the Canadian Maritimes should squash most convection. Otherwise, upper level flow becoming southwesterly will help usher in a warmer air mass with 850hPa isotherms reaching +14C to +15C. Forecast soundings support deep boundary layer mixing as drier air rotating around the mid-level ridge advects into the region. This should support sfc temperatures to become very warm reaching into the upper 80s in the valley with low to mid 80s in the hill towns and upper 70s in the higher terrain. Dew points rise into the low to mid-60s making it feel quite muggy/uncomfortable. Initially clear skies Friday evening will trend cloudier overnight thanks to increased southwesterly flow contributing to moisture advection ahead of the slow approaching mature/closed low from the Great Lakes. Temperatures will be milder compared to previous nights thanks to increased cloud coverage with overnight lows in the low to mid 60s. It will continue to feel muggy as dew points remain elevated. The associated warm front/triple point from the approaching low will be slow moving and with sfc high pressure shifting into the Canadian Maritimes, southeasterly sfc flow will become established. This will keep skies cloudy and conditions muggy with the pressure gradient between the offshore high and incoming low tightening. This should support somewhat breezy southeasterly sfc winds with gusts up to 20kts at times. Cloudy skies and onshore flow will keep temperatures cooler with highs only topping out in the mid to upper 70s as remain ahead of the warm front. The incoming low remains slightly positively tilted and the stronger height falls will slowly spread from west to east through the day, initially reaching the southern Adirondacks and Mohawk Valley before spreading towards the Hudson Valley during the afternoon. Thus, we continue to show chance POPs for areas of showers Saturday morning rising to likely for the western/southern Adirondacks and Mohawk Valley with chance POPs spreading into the Hudson Valley by the afternoon. Areas in western New England should remain dry most of the day as they likely remain displaced far enough east. Given the cloudy skies most of the day, overall instability will be limited despite the muggy conditions. Therefore, we only show chance and slight chance for thunderstorms mainly west of the Hudson River where lapse rates will be a little steeper closer to the low. Areas to the east will be under more of the stable/marine influenced air mass. Cloudy skies continue Saturday night keeping conditions mild and muggy with overnight lows only in the mid to upper 60s. Areas of showers remain possible, especially west of the Hudson River, as the warm front and the associated low and mid level convergence approaches. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Continued chances for rain and some thunderstorms capable of heavy downpours continues Sunday into Monday as our slow moving upper level low gradually opens up as it progresses from the Great Lakes into the Northeast. Southerly flow ahead of the trough axis will support moisture advection with PWATs nearing or even slightly exceeding 1.50". Mostly cloudy skies will likely limit overall instability but elevated dew points in the 60s will likely support at least some instability. We therefore continue to message slight chance to chances for thunderstorms but likely to even categorical POPS (60 - 90%) for rain Sunday through Monday. There is potential for heavy downpours and repeated areas of heavy rain as deep southerly flow is maintained through the column within the moisture rich environment ahead of the approaching trough Sunday with the sfc cold front and trough axis tracking through on Monday. WPC considered introducing a slight risk in its Excessive Rainfall Outlook for Sunday - Monday but given uncertainty on the exact placement of any heavy rain plus antecedent dry conditions, we collaborated to just maintain a marginal risk at this time. Should confidence increase that heavy rain may result in flash flooding, we can revisit the need to upgrade to a slight risk in WPC`s ERO. Guidance has trended to show drier conditions finally arriving by Tuesday through Thursday as a large Canadian high pressure from Canada builds southward, ushering in a drier and much cooler air mass. Temperatures should actually run cooler than normal for mid to late August standard with high temperatures only rising into the 70s with overnight lows dropping into the 50s. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Through 00Z Saturday...VFR conditions start the TAF cycle at KALB/KGFL/KPSF/KPOU with some mid level and high clouds around, as well as some high level smoke. Expecting the mid and upper level trough to move away overnight near Nova Scotia with high pressure building in at the surface. The mostly clear skies and light to calm winds with recently wet ground at KGFL will allow IFR/LIFR radiational mist/fog and low stratus to form. We used a TEMPO group for IFR mist 04Z-07Z/FRI, and then went IFR/LIFR to 12Z/FRI. KPSF also should see radiational mist/fog form around 04Z-06Z and it continues to about 12Z/FRI. KALB/KPOU we placed some MVFR patchy mist and MIFG 09Z-12Z/FRI with less confidence with IFR conditions. The mist/fog should dissipate around 12Z/FRI with VFR conditions prevailing to the end of the TAF cycle at 00Z/SAT. Expect some sct-bkn cirrus and a few cumulus 5-6 kft AGL. The winds will become light to calm prior 04Z/FRI. The winds will be light from the south to southeast less than 10 KT from the late morning through the afternoon. Outlook... Friday Night: No Operational Impact. NO SIG WX. Saturday: Moderate Operational Impact. Breezy. Chance of SHRA...TSRA. Saturday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Sunday: High Operational Impact. Likely SHRA...TSRA. Sunday Night: High Operational Impact. Definite SHRA...TSRA. Monday: High Operational Impact. Definite SHRA...TSRA. Monday Night: High Operational Impact. Likely SHRA...TSRA. Tuesday: Moderate Operational Impact. Chance of SHRA. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Speciale/Wasula NEAR TERM...Speciale/Wasula SHORT TERM...Speciale LONG TERM...Speciale AVIATION...Wasula