Note: This will be my last post until Monday, October 14 or Tuesday, October 15
Summary: The cold frontal squall line came through Berkshire County slightly earlier than expected yesterday with a burst of heavy rain and gusty winds between 4 and 4:30 pm. The BCC weather station reported a maximum gust of 39 mph at 4 pm. Other gusts reported were 40 mph at the Pittsfield airport and 40 mph in Peru. This, however, was enough to bring down a few trees across the county. Interestingly, by the time the squall line reached Berkshire, since we did not have much in the way of surface layer heating (sunshine), there was not even enough instability to generate much in the way of lightning and thunder. The Storm Prediction Center had numerous reports of wind damage across the Northeast but NO hail or tornado reports. Although there were some pre-frontal rain showers (some came through here early to mid afternoon), no supercell thunderstorms (most tornadoes form in this type of storm) formed in advance of the squall line. All of the wind damage was from “straight-line” winds from the frontal squall line. Just to note, tornadoes are relatively rare in these squall lines, and when they develop they are usually weak (EF0, EF1). Rainfall totaled 0.41″ at the BCC weather station and also 0.41″ at the Lanesboro mesonet station but all other reported rainfall totals were between 0.50″ (Savoy) and 0.95″ (Alford).
Surface high pressure is building into the region today following the frontal passage resulting in clear skies and more seasonable temperatures and dewpoints. As mentioned yesterday, this high pressure system will try to hold its own against a pesky surface low pressure system which is developing off the Carolina coast along a stalled portion of the cold front (same one that barreled through here). [Some of the moisture wrapped up in this low is actually remnants from TS Karen]. This low will try to advance north into the Northeast but will probably be held at bay by the high pressure system building over the Northeast. If it weren’t for this little storm we would see clear blue skies from now through the weekend. Instead, it appears the storm will spread a layer of high and mid-level clouds over us Thursday and Friday so that skies may become relatively cloudy during the afternoon Thursday and through Friday morning. The U.S. mid/long-range forecast model (GFS) keeps us relatively dry, with the precipitation staying to our south for the most part, but the European model (ECMWF) has widespread showers spreading over Berkshire County Thursday afternoon into Friday morning. Therefore, it is not a high confidence forecast for that period, particularly since the low will be spinning around without much in the way of steering currents. At this point, I would keep at least the chance of showers in the forecast for Thursday afternoon through Friday, particularly for South County. Right now, it appears that the storm will begin to dissipate and drift out to sea and surface high pressure will build back in from the north, allowing sunny skies to return for most of Columbus Day weekend.
Tuesday Night
Mostly clear, calm and cold with frost in many locations.
Low temperatures in the low to mid 30s. The coldest temperatures and greatest risk for frost is in elevated valley locations.
Calm winds.
Wednesday
The sun will be dimmed at times by afternoon high clouds, otherwise mostly sunny.
High temperatures in the low 60s in Pittsfield, North Adams, Adams and Williamstown; low to mid 60s in Lee, Stockbridge, Great Barrington and Sheffield and; upper 50s to near 60 over the elevated terrain and hilltowns, depending on elevation.
Easterly winds at 5-10 mph.
Wednesday Night
Increasing clouds.
Low temperatures in the low 40s.
Calm winds.
Thursday
Mostly cloudy with a chance of showers late in the day. Probability of precipitation 30%.
High temperatures near 60 in Pittsfield, North Adams, Adams and Williamstown; low 60s in Lee, Stockbridge, Great Barrington and Sheffield and; mid to upper 50s over the elevated terrain and hilltowns.
Light northeasterly winds.
Thursday Night
Mostly cloudy with a chance of showers, particularly over South County. Probability of precipitation 50%.
Low temperature in the mid to upper 40s.
Light northeasterly winds.
Friday
Mostly cloudy with a chance of showers in the morning, partly sunny in the afternoon. A little milder, with high temperatures averaging in the mid 60s.