6:40A-WED: NASTY STORMS EXPECTED LATE AFTERNOON INTO EARLY EVENING WITH POTENTIAL FOR A TORNADO, A MICROBURST, DAMAGING STRAIGHT LINE WINDS, HAIL, AND LOCALIZED FLASH FLOODING GENERALLY NORTH OF THE RT. 9 CORRIDOR IN WMASS/CMASS… COULDN’T WE ALMOST HAVE IT ALL? YES, SOME OF US COULD… 4-9PM TIMEFRAME… SHOWERS AND STORMS POSSIBLE THEREAFTER AS WELL LASTING AFTER MIDNIGHT, BUT SEVERE THREAT WOULD BE OVER BEFORE MIDNIGHT… COOLER/SHOWERY THURSDAY, STUFF HAPPENS FRIDAY AND SATURDAY, YELLOW-WHITE ORBALICIOUSNESS ON SUNDAY INTO EARLY NEXT WEEK, BUT TODAY I’M FOCUSED ON TODAY… 2022 CALL FOR REGIONAL FAN PHOTOS FOR INCLUSION IN MY NEXT WEATHER WALL CALENDAR IS OPEN THROUGH 9/26, PLEASE MESSAGE ME FOR INSTRUCTIONS/DETAILS…

Good morning folks, I don’t like to be the bearer of bad weather news, but for folks in the Berkshires, Taconics, western hilltowns and generally north of the Rt. 9 corridor in MA, on especially north of Rt. 2 on up into SVT and SWNH, you’ve got be weather aware today, as severe thunderstorms are expected.

Remember: t-storms are mesoscale, that means SMALL scale. And their damaging wind cores and hail cores can knock a dozen trees down in one neighborhood, and 1000 feet away it’s like nothing happened.

So unless we’re getting a derecho (widespread wind damage), which we’re not expected to today, the areas mentioned that will be most likely to see severe weather would see localized areas of wind, flood, and possibly hail damage.

Having prefaced this morning’s weather book accordingly, we’ll jump into the details below, but first a word from our local and delicious sponsor #Chomp.

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DISCUSSION:
We’ve got some fog in CMass and a few other spots, and also some low level stratus clouds. These will slowly break up as the morning progresses, leading to a partly sunny day at best, with likely more clouds than sunshine.

While this could tamp down the severe threat by limiting surface heating, I don’t think we’ll be able to keep today’s late-summer surge at bay.

A few showers will be possible later this morning into early afternoon, but no big whoop in the very near term.

HEAT INDEX OVER 90º FOR SOME
High temps are expected to reach the upper 70s to mid 80s for most of us, but if we can squeeze out some sunnier periods, portions of the southern valley could jump into the upper 80s, and heat indices for some of those locales could exceed 90º, with dewpoint temps surging well through the 60s, and reaching 70º in a few spots – summah!

SETUP
We’ve got a warm front that has tracked northeast of the WMass region.

We have a cold front pressing southeast into the eastern Great Lakes.

We have an upper level low moving into the Great Lakes, and wind maxima that will be helping to push strong wind shear into our region this afternoon, especially in northern MA, SVT and SWNH.

We are expecting strong instability to pool at the surface, and we have plenty of humidity and moisture to work with, and winds will gust out of the southwest up to 25mph at times.

We have the moisture, the lift/forcing, the instability and the wind shear maximizing in central VT, NH and western ME, with its southern extent down into the central/northern Taconics of eastern NY, SVT, SWNH, and northern MA, which leads us to…

SEVERE THUNDERSTORMS W/ MULTIPLE THREATS
–We’ll likely see two lines of storms
–The first will be the pre-frontal trough region, which could spawn a couple of supercells
–These supercells may produce tornadic activity, large hail, and damaging wind gusts with torrential rain
–These would move into the region on the earlier side of the 4-9pm timeframe
–Then we’d see a second squall line ahead of the actual cold front, which could move in during the latter half of that timeframe
–The threats there would be more like straight-line wind damage and large hail, with bow echo signatures (eastward-bulging radar signatures that indicate strong wind, and occasionally frontally-hinged tornadoes, but not usually)
–Again, we can’t rule out a tornado or two, or a microburst

Any storms should weaken as you travel further south of the Rt. 9 corridor in MA, down into CT/RI, as those storms will be outrunning the better dynamics to the north.

After the severe threat wanes later tonight, we will still see some showers, heavy at times, along with a few rumbles of thunder around or after midnight, quitting likely before dawn Thursday morning, with lows in the upper 50s to low 60s.

For Thursday, the front stalls toward the southern New England coastline, and high pressure builds into our northeast.

With clockwise flow, easterly wind develops into southern New England, with occasional showers at times, partly sunny to mostly cloudy skies, and highs in the upper 60s to low 70s with lows near 60º.

I think this potential tropical depression off of the eastern seaboard will generally stay out to sea, and not cause too many headaches in the WMass region for Friday and Saturday, but a few showers are possible at times with highs in the 70s and lows near 60º.

Sunday into early next week looks sunnier, drier, nicer, hooray!

For now, though, we stay glued to potential severe weather threats this afternoon and evening, so keep it tuned here, and I will be updating during the day and evening as this potential severe weather outbreak (for some north of the Rt. 9 corridor in MA, VT and NH) unfolds and develops.

Have a great day, and please stay tuned!