Area Forecast Discussion
Issued by NWS Albany, NY

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000 FXUS61 KALY 291836 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 236 PM EDT Fri May 29 2020 .SYNOPSIS... Warm and humid conditions continue through today with showers and thunderstorms, especially during the afternoon and evening ahead of an approaching cold front. Some storms could become severe. The cold front exits Saturday morning and cooler and drier weather is expected the rest of the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 236 PM EDT...Severe Thunderstorm Watch #234 in effect for all of eastern Upstate New York through 9 PM EDT. Our region remains situated within a rather warm and humid environment. With a southerly flow at low levels, dewpoints remain in the upper 60s early this afternoon. Visible satellite imagery shows plenty of breaks in the clouds over most of the area, which has allowed valley temps to surge into the lower to middle 80s. The warmest temps are right around the Capital Region, where temps have reached up to 89 degrees according to KALB ASOS and NYS Mesonet observations. Showers and thunderstorms have been increasing in coverage and strength across the region, especially across the Saratoga Springs-Glens Falls area, where a thunderstorm produced lots of lightning is now capable of severe winds as well. As the upper level forcing continues to get closer, the combination of MLCAPE of around 1500 J/kg and 0-6 km bulk shear of 30+ knots will allow for additional severe storms through the evening. As the convection over western New York heads eastward, 3km CAMs suggest some organization into lines or linear clusters will occur for the late afternoon into the evening hours. This activity will need to be monitored for a more widespread threat for severe storms across our area as they move from west to east. The main threat with any strong storms will be damaging winds. Midlevel lapse rates are expected to be around 6 to 6.5 C/Km by later today, which is enough to sustain updrafts but not necessarily enough to accelerate updrafts, which with the high wet bulb freezing levels suggests some hail potential but hail may contribute more to enhancing downdrafts and wind damage. Low level shear will be enough for some rotating storms, especially as shear increases late in the afternoon and toward evening. An isolated tornado cannot be ruled out. Low level dew points well into the 60s to near 70 and low lifted condensations levels also support the potential for an isolated tornado. Locally heavy rain is also possible if training can set up with ponding of water on roadways and low lying areas. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... The severe weather threat continues this evening until some diurnal cooling begins and instability decreases. Low level jet energy strengthens through the evening, suggesting the damaging wind and isolated tornado threat continues until the organized storms associated with the pre frontal trough exit. After midnight, thunderstorms should be confined to the southern Berkshires, mid Hudson Valley and NW CT. Due to decreasing instability with cooling temperatures, much of the severe weather threat should end by that time also. Still, some locally heavy rain is possible through the early morning hours in lingering thunderstorms. Some partial clearing is likely as the low level winds shift to west and northwest and low level cold advection begins to spread across our region. There is one more piece of upper energy that will track north and east of our region and the leading edge of the core of coldest air will track through Saturday afternoon and evening. There could be isolated showers north of the Mohawk Valley Saturday afternoon along the leading edge of this reinforcing cooler air. Highs Saturday in the 70s but near 80 mid Hudson Valley and mid to upper 60s southern Adirondacks. Clearing and cooler Saturday night and Sunday with highs Sunday in the 60s to near 70 but 50s higher terrain. Will have to keep an eye on some frost potential in the southern Adirondacks for Sunday night. && .LONG TERM /MONDAY THROUGH THURSDAY/... The period starts out on Monday with an upper level trough axis gradually moving eastward into New England during the morning, with a cyclonic northwest flow regime still lingering through much of the day. The best forcing will be east of our region, so at this time only isolated showers are expected. It will be a cool day, with temperatures a good 10 degrees below normal for early June. Dry and cool conditions in store for Monday night, as a ridge of high pressure builds in from the south and west. Tuesday should feature continued dry conditions, along with a slight moderation in temperature as the low level flow shifts from northwest to southwest. Northwest flow aloft will be theme of the week, with occasional disturbances moving through. The first disturbance looks to move across the region Tuesday night bringing scattered showers. Models then start to diverge, with the chaotic/fast flow regime persisting. Typical large dispersion in the guidance with regards to the placement and track of quick-moving disturbances. Given a relatively high confidence in the flow pattern and low confidence in timing/coverage of showers associated with disturbances, will mention mainly chance pops from Wednesday through Thursday. At this time it appears instability would be limited with near normal temperatures and dewpoints not overly moist (40s to mid 50s). Will mention just slight chance of thunder west of the Hudson Valley. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... NWS WSR-88D Radars showing isolated to scattered showers and thunderstorms developing across New York State north and west of the mid Hudson Valley. Chances for scattered thunderstorms will increase across the Albany Forecast Area during the late afternoon into the evening. Have included tempo for thunder in TAFs as latest convective allowing models show coverage to increase substantially this afternoon. Scattered showers and thunderstorms will linger through much of the evening, as a slow moving cold front progresses eastward. Cold front should be east of the TAF sites by mid morning Saturday and winds will become more west to northwest tomorrow. Winds today will be southerly around 10-15 kt with gusts of 20-25 kt, especially at KALB/KPSF. Stronger winds gusts will be possible within any thunderstorms later this afternoon and evening. Winds will shift to the west tomorrow morning after the cold front passes. Outlook... Saturday: Moderate Operational Impact. Chance of SHRA. Saturday Night: No Operational Impact. NO SIG WX. Sunday: Low Operational Impact. Breezy. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: Low Operational Impact. Slight Chance of SHRA. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... A warm and humid conditions continue through today with showers and thunderstorms, especially during the afternoon and evening ahead of an approaching cold front. Some storms could become severe. The cold front exits Saturday morning and cooler and drier weather is expected the rest of the weekend. The humid conditions along with chances for rain through tonight will keep RH values above 60 percent. Cooler and drier air will be in our area Saturday with RH values falling to the 50 to 65 percent range by afternoon. South winds through tonight will gust to 20 mph. Winds shift to west and northwest early Saturday morning at around 15 mph. Winds could gust to 20 mph Saturday afternoon. && .HYDROLOGY... Through tonight, a warm and humid airmass will interact with an approaching cold front to generate showers and thunderstorms. Locally heavy downpours can be expected, but widespread hydrological issues are not anticipated. Long-term conditions remain dry, with portions of Herkimer and Hamilton Counties in abnormally dry conditions (D0) per latest Drought Monitor. Basin average QPF of 0.50 to 1.25 inches here may help conditions. Elsewhere, basin average totals of 0.50 inches or less are expected. Locally heavy rain is likely in thunderstorms with some areas seeing ponding of water on roadways and low lying areas but no river flooding is expected. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...NAS NEAR TERM...Frugis/NAS SHORT TERM...NAS LONG TERM...JPV AVIATION...SND FIRE WEATHER...NAS HYDROLOGY...NAS is the U.S. government's official web portal to all federal, state and local government web resources and services.