Marine Weather and Tide Forecast for Williams, MA

NEAR TERM /THROUGH FRIDAY/
Key Messages:

- Severe Thunderstorm Watch in effect through 9 PM for all of eastern New York and western New England. Scattered thunderstorms will have the capability of producing damaging wind gusts, flooding rainfall and frequent lightning. Hail possible within the strongest storms as well.

_ Heat Advisory remains in effect for portions of the Hudson Valley where heat index values will climb around to above 95 degrees this afternoon.

Discussion:

As of 730 PM, widely scattered showers and embedded storms continue to develop over eastern NY into western New England early this evening as as our main shortwave trough seen on the latest water vapor imagery is finally tracking into western NY resulting in stronger forcing for ascent. The main sfc cold front is pushing through central NY with a line of showers/embedded storms now approaching the Mohawk Valley.
While IR satellite imagery does not show cloud top temperatures cooling which would signify intensifying updrafts, the air mass ahead of the line is still quite warm/humid with some elevated instability ranging 1-2k J/kg and plenty of deep layer shear 30-40kts as seen on the 00 UTC ALY sounding. Will continue to keep an eye on radar trends but expect a period of showers to push through this evening from west to east with perhaps a few rumbles of thunder. CAMs are not enthusiastic about additional severe weather but given the increased forcing, will still keep a close eye and maintain the severe thunderstorm watch through 9 PM. Activity should wane by Midnight, as nocturnal cooling takes over the surface cold front crosses the area from west to east.

Lows overnight will fall into the upper 50s to mid 60s. Winds will be switching to the west behind the front and become rather gusty for the late night hours thanks to a decent pressure gradient in place. Some gusts up to 30 mph are possible through daybreak Friday.

SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/
Key Messages:

-Despite wind gusts likely remaining below wind advisory criteria, breezy conditions on Friday morning could lead to some downed tree limbs.

Discussion:

Behind the departing cold front, good mixing and a strong pressure gradient will allow for gusty winds on Friday, especially in the morning hours. Some gusts may reach 20-35 mph.
NBM probabilities for gusts over 40 mph are fairly low for most places (highest value is around 30% for the Berkshires), so we probably won't reach wind advisory criteria. However, these gusts are somewhat uncommon for this time of year and with fully-leaved trees (and fairly wet soils), some downed trees or limbs are possible. Otherwise, skies will be partly to mostly sunny on Friday. It will be noticeably cooler and less humid with temps only in the mid 70s to low 80s and dewpoints back down into the 50s.

For Friday evening into Friday night, some scattered showers and possible thunderstorms may spread from west to east towards our western and southern areas, although this somewhat uncertain at this time. Another front will be approaching from the northwest and some activity may race out ahead of the front and spread into our area from the west. At this point, no severe storms are expected, but some localized downpours can't be ruled out.
Otherwise, it should stay partly cloudy into Friday night with lows in the mid 50s to mid 60s.

Temps will start to rise once again on Saturday, with valley highs back up into the 80s and dewpoints creeping back up into the 60s. Most of Saturday looks dry, although some showers and thunderstorms are possible for Saturday evening into Saturday night, as an MCS may spread into the our from the northwest.
Models have some differing ideas regarding the exact timing of this feature, but a cluster of showers and storms could track across the area at some point for late Saturday into the overnight (or even linger into early Sunday). It will remain mild and muggy into Saturday night with lows staying around 70.

LONG TERM /SUNDAY THROUGH THURSDAY/
Key Messages:

- High confidence exists in a prolonged period of dangerously hot and humid conditions beginning early through the middle of next week with the most dangerous of these conditions falling to Monday and Tuesday. Heat Advisory and/or Extreme Heat Warnings will likely be needed.

Discussion:

An early-season heat wave is expected to impact the region during the long term period. Model guidance (including the latest 12z GFS and ECMWF) shows a strong upper level ridge at 500 hpa setting up along the eastern portion of the CONUS for late in the weekend into early next week. A 598 dm ridge looks to be centered just southwest of the area and 850 hpa temps will be rising as high as +20 to +22 C.

The latest NBM shows some impressive values for this far out.
The mean values from the latest NBM show max temps in the mid to upper 90s for the Hudson Valley, including the Capital Region for both Monday and Tuesday. NBM probabilities for max temps on Monday exceeding 100 degrees is 75% for Albany (which hasn't officially occurred since 1953) and nearly 90% for Poughkeepsie.
With dewpoints in the 70s, heat index (feels-like temperatures)
will be over 100 degrees in many valley areas and could be as high as 110 degrees, which is fairly unusual for this part of the country. NWS Heat Risk categories reach Major (Level 3 of 4)
for both Monday and Tuesday. This could be a historic heat outbreak and Heat Advisories and/or Extreme Heat Warnings will likely be needed for much of the area. While Sunday will start to be hot, the extreme heat looks to be Monday and Tuesday, with temps starting to possibly lower by Wednesday.

After any morning showers/convection on Sunday, the developing strong ridge should prevent any convection from Sunday afternoon through at least Tuesday. Skies will be mostly clear through this time. Next chance for any convection could be Wednesday, as some activity tries to run across the top of the ridge.

AVIATION /02Z FRIDAY THROUGH TUESDAY/
Through 00z Saturday...VFR conditions prevail early this evening but with the main cold front now approaching from our west, additional widely scattered showers and a few storms are popping up ahead of a more organized line of showers and embedded thunderstorms. This line of showers/isolated storms does not currently have any severe weather associated with it but given we still have hot and humid air in place ahead of it, we cannot completely rule out an isolated strong storm. Not enough confidence to place TSRA in the latest TAF update but used a TEMPO group to outline the timing of the incoming line of showers from 02 UTC to 06 UTC. MVFR vis/cigs are possible during this window. If any storms will impact a terminal, we handle with an amendment.

After the main line of showers exits around or shortly after Midnight from west to east, VFR cigs/vis return but winds turn gusty and quite strong for this time of year. Expecting winds to shift to the west to west-northwest and become sustained 6-14kts with gusts up to 25-30kts (strongest at ALB and PSF).
The strongest wind occur late tonight through tomorrow morning before gradually weakening through the afternoon but still rather gusty (20-25kts). Winds do not diminish until near the end of the TAF period (23 - 00 UTC/Fri).

Outlook...

Friday Night: No Operational Impact. NO SIG WX.
Saturday: Low Operational Impact
Slight Chance of SHRA
TSRA.
Saturday Night: Moderate Operational Impact
Chance of SHRA
TSRA.
Sunday: Low 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: Low Operational Impact
Slight Chance of SHRA
TSRA.

CLIMATE
Record high temperatures for June 23 and June 24:

June 23 Albany, NY: 96 degrees set in 1888 Poughkeepsie, NY: 94 degrees set in 1965 Glens Falls, NY: 95 degrees in 1894

June 24: Albany, NY: 96 degrees set in 1943 Poughkeepsie, NY: Poughkeepsie, NY: 94 degrees set in 2013 Glens Falls, NY: 95 degrees in 1914

ALY WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
MA...None.
VT...None.