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
503 FXUS61 KALY 131955 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 355 PM EDT Thu Jun 13 2024 .SYNOPSIS... Dry weather is expected through the first half of tonight, but there is a chance for showers and thunderstorms tomorrow mainly during the afternoon and evening. A few storms could be strong to severe south and east of the Capital District. Then, cooler and drier weather returns for the weekend. Temperatures warm up significantly heading into next week, with temperatures and humidity potentially approaching dangerous levels Tuesday through Thursday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 3:55 PM EDT...Flat upper ridging remains over our region, with surface high pressure located well to our east over the Atlantic. South/southwest flow around the high and warm advection have lead to daytime highs climbing into the mid 80s for many valley areas under partly to mostly clear skies. Additionally, a surface low is now developing to the north of the Great Lakes in association with a potent upper shortwave... Tonight, the surface low deepens to sub-990 mb as it and the upper shortwave track north of the Great Lakes into eastern Canada. Ahead of these features, a weak upper impulse and pre- frontal trough will cross our region, potentially leading to a few showers and possibly an embedded thunderstorm across the Adirondacks. Coverage of showers and thunderstorms gradually spreads further south and east the second half of the night, with a few showers potentially getting to the Capital District around sunrise. With increasing clouds and winds remaining light, it will be on the warmer side with lows mainly in the 60s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... By tomorrow morning, the surface low will be located well to our north, with the trailing cold front approaching from the west. A second upper impulse will help drive this cold front southeastwards through our region tomorrow, which will result in showers and thunderstorms developing across the region. With a warm and relatively moist airmass ahead of the front, a few of these storms could be strong to severe with SPC having placed areas mainly south and east of Albany in a slight risk for severe storms. Highs will be mainly in the upper 70s north and west of the Capital District, with mid 80s possible in the Mid Hudson Valley and western CT. With the approaching cold front, upper shortwave, and the right entrance of the upper jet nearby, there will be decent forcing for ascent so showers should be fairly widespread tomorrow afternoon. Regarding the severe potential, the HREF mean suggests SBCAPE values of up to 1000-1500 J/kg overlapping with 30-40 kt of deep-layer shear. The shear profile is relatively top-heavy, but should still be sufficient for some organized convection. Any initially discrete cells should grow upscale into a line or line segments with the relatively strong forcing and unidirectional shear profile. With low-level dry air and relatively steep low-level lapse rates, damaging winds look to be the main threat with storms, but straight to slightly counterclockwise turning hodographs and strong storm-relative flow aloft also suggest the potential for a few storms to also contain large hail, especially before convection congeals into a line. The best chance for any severe storms looks to be from around noon through 00z, again focused south and east of the Capital District. One potential "failure mode" for severe weather is if morning showers/non-severe convection end up tracking further south and east than currently expected. If the morning showers make it south and east of the Capital District, then the risk for severe weather later in the day would be lower. Locally heavy rain is also possible with any storms, but with PWATs "only" around 1.5 inches, progressive storm motions, and dry antecedent conditions we are not expecting widespread hydro issues. Of course, the typical nuisance urban/poor drainage flooding is always possible should any of these heavier rainfall rates move over any urban areas. Showers and storms may linger into the evening tomorrow, but should come to an end between 00z and midnight. Things should dry out behind the cold front, with cooler and drier air being advected into the region. Lows will be in the upper 40s for the ADKs to mainly 50s elsewhere. Saturday and Sunday...We remain in a cool/dry advection regime behind the cold front, with surface high pressure building into the region with northwest flow aloft. It will be much cooler on Saturday with highs in the 60s for the terrain to 70s in the valleys. With the high directly overhead Saturday night, it will be quite cool with most areas dropping into the 40s and even a few upper 30s possible in the high terrain. Sunday remains dry but will be slightly warmer with highs mainly in the 70s. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... Long term period begins Sunday night with surface high pressure sliding off the east coast of New England. A warm front will lift northeastwards across the region late in the overnight period, so lows will be a few to several degrees warmer than the previous night with lows in the 50s to around 60. Monday, we get into south/southwest return flow and warm advection around the periphery of the upper high. Upper ridging begins to build over the eastern half of the CONUS, so it will be quite a bit warmer than the previous couple days with highs in the mid 80s. This will be the start of a significant warming trend, as the upper ridge continues to amplify over the eastern US through the middle of next week. Ensemble guidance is in good agreement that most of our area will be within the 594 dam contour, with some deterministic guidance suggesting we may see 600 dam heights at 500 mb somewhere in the Mid Atlantic or Northeast. 850 mb temperatures climb into the low 20s Celsius, which will translate to surface temperatures in the 90s for many of our valley areas each day Tuesday through Thursday. With dew points well into the 60s each day, afternoon heat index values are may potentially reach or exceed 100 degrees for many valley areas Tuesday through Thursday. Heat advisories will likely be needed as we get closer to this event, with excessive heat warnings not completely out of the question. Overnight lows will be in the upper 60s to around 70, so even at night it will remain quite warm and muggy. Forecast confidence is relatively high that we will see hot/humid weather next week, although just how hot it gets remains somewhat uncertain. One potential factor that could lower temperatures slightly is an upper shortwave that will be tracking around the northern periphery of the ridge sometime Monday or Tuesday. All sources of guidance have this feature, although they differ on its track and timing. Where this feature tracks, there will be a few more clouds with isolated to scattered afternoon showers and thunderstorms, which could locally reduce temperatures. At this point, the greatest chance for a few showers or thunderstorms looks to be mainly north of I-90. Even if the "cooler" scenario were to play out, we would still likely see many areas reach or exceed heat advisory criteria Tuesday through Thursday. Confidence decreases for the middle and end of next week with most sources of guidance suggesting the ridge will break down at some point, but it is too soon to tell exactly when this will happen. The CPC is still expecting temperatures to average above normal for the 8-14 day timeframe. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... Through 18z/Fri...VFR conditions will remain in place into this evening with some fair weather cumulus and high cirrus around. A cold front will slowly approach the region overnight into Friday morning. A few rain showers may develop ahead of the front prior to daybreak near KALB/KGFL and near or after daybreak at KPSF. Cigs/vsbys may remain in the VFR range within these showers. Showers and thunderstorms are expected to develop between 16-18z/Fri, mainly affecting KALB/KPSF/KPOU. With the timing of these showers closer to the end of the current TAF period, will refer to later TAF issuances for further details. Wind will be south to southwesterly at around 10 kt this afternoon into this evening before decreasing to less than 10 kt tonight into Friday morning (except remaining around 10 kt at KALB). Outlook... Friday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. 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. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Main NEAR TERM...Main SHORT TERM...Main LONG TERM...Main AVIATION...Rathbun