Area Forecast Discussion

WHAT HAS CHANGED

Tornado Watch #507 cancelled. Reduced rainfall chances for the next few hours across most of southern VT, western MA, and eastern NY outside of the mid Hudson Valley and SE Catskills given current radar trends.

KEY MESSAGES

1) Additional showers/thunderstorms across western NYS will track eastward later this evening, though should be weakening in intensity, with showers/storms with locally heavy rain redeveloping across portions of the mid Hudson Valley, SE Catskills and NW CT later this evening.

2) Tranquil weather with temperatures trending slightly above normal Thursday into this weekend.

DISCUSSION

KEY MESSAGE 1...

As of 8 PM EDT, band of showers/storms associated with warm advective regime has shifted mainly east of the region. However, additional isolated/scattered showers and thunderstorms across NE PA will continue expanding northeast this evening. Additional locally heavy downpours will be possible with these as they expand into the mid Hudson Valley, SE Catskills and NW CT region.

Elsewhere, showers/thunderstorms across western NY will continue tracking east/northeast, reaching the SW Adirondacks and western Mohawk Valley later this evening, and possibly as far east as the Capital Region, Schoharie County and Lake George region toward or just after midnight. Although can not rule out some spotty gusty winds with this convection, widespread severe weather looks unlikely given loss of diurnal heating. Patchy/areas of fog may develop overnight, especially in areas which received prior locally heavy rainfall.

The warm sector shifts eastward tomorrow as the main cold front and trough axis swings into the Northeast. Given the early arrival of the cold front pushing into the eastern NY by 15 - 18 UTC, the highest chance for the warm sector to have enough time to destabilize before the strongest forcing arrives look to be in areas mainly east of the Hudson River, especially in western New England. The latest Day 2 SPC Outlook continues to place a marginal (level 1 of 5) risk for severe weather in southern Berkshire and Litchfield Counties where there is a favorable overlap of 500-1000J/kg of SB CAPE and 40-45kts of deep layer shear. Latest CAMs shows an initial line of showers developing along the incoming cold front late morning that grows upscale into line segments and storm clusters as it enters western New England and the more unstable environment mainly after 17-18 UTC. Damaging winds will also again be the main hazard through late afternoon before the front finally pushes eastward into New England. Otherwise, humidity will trend downwards behind the cold front from west to east through the day with clearing skies.

KEY MESSAGE 2...

We will enjoy a stretch of pleasant and dry weather Thursday through this weekend as high pressure builds overhead. Temperatures trend upwards Friday into the weekend as high pressure builds off shore promoting southwesterly return flow but we do not expect oppressive heat. Another shortwave approaches late this weekend into early next week but there is still uncertainty on timing and placement of any showers or convection.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

VFR to MVFR conditions begin the 22/00z TAF period. Between 1z and 6z, MVFR to IFR ceilings begin and continue through the 9-12z timeframe. For MVFR to IFR visibilities due to fog development is likely at KPSF between 3z and 6z before stratus clouds become more dominate and decrease fog development. Otherwise after 12z, ceilings gradually improve back to VFR and continue through the end of the TAF period. Winds continue to be light and variable into the overnight hours before becoming westerly ranging between 10 and 15 knots for tomorrow afternoon.

Outlook...

Wednesday Night: No Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. Thursday Night: No Operational Impact. NO SIG WX. 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.

ALY WATCHES / WARNINGS / ADVISORIES

CT...None. NY...None. MA...None. VT...None.