Summary: We remain under a sprawling ridge of high pressure, with the jet streamand its attendant storms/low pressure systems located to our north over southern Canada. This pattern will persist, with fair skies and mild temperatures through the remainder of the week. As the jet stream lifts even farther to our north on Tuesday and Wednesday, even warmer air will enter our region and high temperatures will climb well into the 70s on both days.

A weak wave will pull the jet stream south and its southern margin will come through, manifested as a weak cold front at the surface, Wednesday afternoon and evening. The front should come through dry, with nothing more than a thin band of clouds. Temperatures will be a little cooler on Thursday, but still above normal, reaching the low 70s on average, and skies should remain mostly sunny.

The weak front will move back over us as a weak warm front on Friday as the jet stream retreats back to the north. This will cause more cloudiness on Friday afternoon and night, with a chance of a few scattered showers.

Once the warm front passes, and the jet stream again lifts to our north again, the southwest flow around the semi-permanent subtropcal high pressure system (Bermuda High) to our southeast will push warmer, and even humid, air back into the region. Temperatures look to rise, once again, well into the 70s with at least some sunshine and little chance of rain over the weekend.

Monday Night

Clear, calm and seasonably cool. As on previous nights, patchy fog may form in valley locations

Low temperatures in the low 40s.

Calm winds.

Tuesday

Mostly sunny and warm.

High temperatures in the low to mid 70s in Pittsfield, North Adams, Adams and Williamstown; mid 70s in Stockbridge, Great Barrington and Sheffield and; near 70 to low 70s over the elevated terrain and hilltowns, depending on elevation.

Light west-northwesterly winds in the morning, increasing to 5-10 mph in the afternoon.

Tuesday Night

Clear and not quite as cool as previous nights.

Low temperatures generally near 50.

Light westerly winds.

Wednesday

Mostly sunny, breezy and even warmer. There may be a brief period of increased cloudiness as a weak cold front passes in the late afternoon.

High temperatures in the mid to upper 70s in Pittsfield, North Adams, Adams and Williamstown; upper 70s in Stockbridge, Great Barrington and Sheffield and; low to mid 70s over the elevated terrain and hilltowns, depending on elevation.

West-southwesterly winds increasing to 10-20 mph by early afternoon, with some stronger gusts, particularly over the higher terrain. Winds will shift to west-northwesterly with cold front passage late in the afternoon.

Thursday

Mostly sunny and slightly cooler, with high temperatures averaging in the low 70s. There may be an increase in high clouds during the afternoon.

Although there is no weather discussion on this page for Saturday, September 28, I have updated the forecast on the weather station page. Bottom line: continued fair and mild for the foreseeable future. The annoying little coastal storm will be well out to sea on Monday.

Summary: Ooops! The weak upper-level disturbance that I had mentioned would rotate through New England today created a more solid overcast than expected. The cloud cover also kept us quite cool (about 10 degrees cooler than expected, which is typical). Sorry about that…..Don’t worry though. The clouds will clear out tonight and we should still have a mostly sunny and mild weekend.

There now appears to be a fly in the ointment for early next week that MAY disrupt our long string of dry days. A low pressure system presently developing off the southeast coast will drift slowly north and to the east of Cape Cod on Monday. This relatively weak, and compact storm system could track close enough to the coast to give us some light rain or showers during the day on Monday as it passes slowly by on its way to the Canadian Maritime. However, right now it appears that the storm should track just enough to the east that we will only get some cloudiness from it Monday and Monday night and should still remain dry. The GFS model is the only one giving us any rain and, in my experience, that scenario is not particularly likely with this type of storm and track. However, I will update the situation over the weekend. It still appears that fair and mild weather will reappear on Tuesday or Wednesday as high pressure builds back in for the remainder of the week.

Friday Night

Cloudy skies early, then clearing as the evening progresses. Becoming clear after midnight.

Low temperatures in the low to mid 40s.

Calm winds.

Saturday

Mostly sunny and mild. Fair weather cumulus clouds may build up a bit during the afternoon, particularly over the elevated terrain, but there should still be more sun than clouds.

High temperatures near 70 in Pittsfield, North Adams, Adams and Williamstown; low 70s in Stockbridge, Great Barrington and Sheffield and; mid to upper 60s over the elevated terrain and hilltowns, depending on elevation.

Light easterly winds.

Saturday Night

Clear, calm and seasonably cool.

Low temperatures generally in the low 40s.

Calm winds.

Sunday

Sunny and mild.

High temperatures near 70 in Pittsfield, North Adams, Adams and Williamstown; low 70s in Stockbridge, Great Barrington and Sheffield and; mid to upper 60s over the elevated terrain and hilltowns, depending on elevation.

Light southeasterly winds.

Monday

Increasing clouds and cooler. There is a chance of light rain or showers in the afternoon but it is more likely that we will remain dry.

Summary: Boring, boring, boring…..but in a good way! There is not much to say that I haven’t already said earlier this week. Surface high pressure will continue to dominate our weather and will crest right over Berkshire County over the weekend. As I indicated yesterday, there may be a bit more cloudiness on Friday, particularly during the afternoon. It should be mostly sunny in the morning. During the afternoon it will likely be partly cloudy (more sun than clouds) in the lower elevations but partly sunny (more clouds than sun) over the elevated terrain. The weekend still looks mostly sunny and mild, with high temperatures averaging from mid to upper 60s over the elevated terrain to low 70s in the lower elevations in South County. There will likely be some buildup of fair weather cumulus clouds during the afternoon, particularly over the elevated terrain but there should still be a good amount of sunshine everywhere.

Thursday Night

Mostly clear, calm and seasonably cool.

Low temperatures in the low to mid 40s.

Calm winds.

Friday

Mostly sunny in the morning. More cloudiness during the afternoon, with partly cloudy skies (more sun than clouds) in the lower elevations and partly sunny (more clouds than sun) in the elevated terrain.

High temperatures in the upper 60s in Pittsfield, North Adams, Adams and Williamstown; near 70 in Stockbridge, Great Barrington and Sheffield and; low to mid 60s over the elevated terrain and hilltowns, depending on elevation.

Light northerly winds.

Friday Night

Clearing in the evening. Becoming mostly clear and calm.

Low temperatures again in the low to mid 40s.

Calm winds.

Saturday

Mostly sunny and continued mild.

High temperatures near 70 in Pittsfield, North Adams, Adams and Williamstown; low 70s in Stockbridge, Great Barrington and Sheffield and; mid to upper 60s over the elevated terrain and hilltowns, depending on elevation.

Winds light and variable.

Sunday

Mostly sunny and mild with high temperatures little changed from Saturday.

Summary: Our quiet fall weather pattern appears ready to hold its ground, even into the long-range (7-10 days) forecast model runs, with dry weather and seasonable temperatures continuing into next week. A broad area of surface high pressure over eastern North America will continue to dominate our weather through the weekend. A weak cold front will give us a slight chance of a shower Sunday night or early Monday before high pressure is re-established next week.

In the more immediate future, the cut-off low over the Canadian Maritime only slung its low clouds back as far west as the easternmost highlands of Berkshire County this afternoon, so that most of the county once again saw clear blue skies today. It appears that the low pressure system will be moving more rapidly eastward over the next few days as it is picked up by the jet stream. Therefore, my outlook has become more optimistic and I believe we should see mostly sunny skies again on Thursday. There will likely be a bit more cloudiness on Friday as a very weak upper-level disturbance rotates through New England from north to south along the back edge of a trough in the jet stream. Still, Friday should be a dry day and skies will only be partly cloudy.

Saturday and Sunday should see a return to full sunshine as the jet stream ridge and surface high pressure become centered over the eastern U.S. Temperatures should be mild over the weekend, with highs possibly reaching into the low 70s.

Wednesday Night

Clear and calm with seasonably cool temperatures. A few areas of patchy fog developing toward morning in some valley locations.

Low temperatures in the low to mid 40s.

Calm winds.

Thursday

Mostly sunny (< 25% cloud cover) and mild. It may be partly cloudy (25-50% cloud cover) over the elevated terrain at times during the afternoon.

High temperatures in the upper 60s in Pittsfield, North Adams, Adams and Williamstown; near 70 in Stockbridge, Great Barrington and Sheffield and; mid 60s over the elevated terrain and hilltowns.

Light northerly winds.

Thursday Night

Partly cloudy and calm with patchy fog developing toward morning.

Low temperatures again in the low to mid 40s.

Calm winds.

Friday

Variable amounts of clouds throughout the day, averaging out to partly cloudy skies, so there should be more sun than clouds.

High temperatures in the upper 60s in Pittsfield, North Adams, Adams and Williamstown; near 70 in Stockbridge, Great Barrington and Sheffield and; mid 60s over the elevated terrain and hilltowns.

Light north-northeasterly winds.

Saturday and Sunday

Mostly sunny and mild with high temperatures around 70 to the low 70s.

Summary: There is not much change to the weather scenario or forecast since yesterday’s discussion. Our weather will be primarily influenced by a ridge of high pressure (full atmosphere) building over the region and its attendant surface high pressure system through at least the weekend. This will gives us dry, generally fair weather and seasonable temperatures for the foreseeable future. As stated yesterday, low level moisture rotating around a cut-off low pressure system over the Canadian Maritime will result in a buildup of clouds during the day Wednesday through Friday, mostly during the afternoon as the atmosphere destabilizes a bit. Aside from some patchy early morning fog, skies should be mostly sunny during the morning with a mixture of clouds and sun during the afternoons. We should see a return to mostly sunny skies over the weekend with high temperatures near 70 (lets hope!!).

Tuesday Night

Mostly clear and seasonably cold. Patchy fog developing toward morning.

There is no significant risk of frost tonight. Low temperatures generally near 40, with some upper 30s over the elevated terrain and in wind sheltered valleys.

Northwesterly winds at 5-10 mph this evening, becoming light after midnight.

Wednesday

After any fog burns off it  will be mostly sunny early, with some build up of low clouds as the day progresses, primarily during the afternoon. There will be a mixture of clouds and sun during the afternoon.

High temperatures in the mid to upper 60s in Pittsfield, North Adams, Adams and Williamstown; upper 60s in Great Barrington and Sheffield and; low to mid 60s over the elevated terrain and hilltowns, depending on elevation.

North-northwesterly winds at 5-10 mph.

Wednesday Night

Partly cloudy and calm with patchy fog developing toward morning.

Night quite as cold, with low temperatures generally in the low 40s.

Calm winds.

Thursday

The weather should be similar to Wednesday…..After any fog burns off it  will be mostly sunny early, with some build up of low clouds as the day progresses, primarily during the afternoon. There will be a mixture of clouds and sun during the afternoon.

High temperatures in the mid to upper 60s in Pittsfield, North Adams, Adams and Williamstown; upper 60s in Great Barrington and Sheffield and; low to mid 60s over the elevated terrain and hilltowns, depending on elevation.

Light winds, varying between northwesterly and northeasterly.

The two day Berkshire County forecast (below the summary) has replaced the Weather Underground forecast linked to BCC’s homepage. Just click on the blue “Weather Station” text (right below the temperature) in the upper-left hand corner of the BCC homepage (www.berkshirecc.edu). This will take you to a webpage hosted by our weather station manufacturer, Rainwise. The page contains streaming data from our own weather station (on the roof of Hawthorne). The forecast on the right side of the page (which used to be by Weather Underground) is now my (Joe Kravitz) forecast taken from the bottom of this post. I will continue to post that forecast on this page with a more detailed and extended forecast discussion (the “Summary” section). Beginning in mid-October, the forecasts will be made by students (working with me) in my Introduction to Meteorology course (ATM-145) as part of lab work for the course. The “Summary” forecast discussion will continue to be posted by me. They will be making their forecasts on Monday, Wednesday and Friday. I will post on the other days of the week as conditions warrant and will continue to post once the semester ends.

Summary: Just a reminder, anything in red, underlined text in this summary is a link to a weather map, usually from one of the forecast models. At the top of the map it states when the model was run (usually 12 UTC, which is 8 am local time) and when the forecast map is “valid” (meaning when the forecast is for, when the map will look like that). Keep in mind that the time is UTC, which is the same as Greenwhich Mean Time. 12 UTC is 8 am (Daylight Savings Time) and 00UTC is 8 pm…….

Our repeating weather pattern continues….Following the passage of a cold front on Saturday night, a broad area of surface high pressure is building back into the Northeast and will dominate our weather for the remainder of the entire work week and possibly right through next weekend. The large -scale subsidence (sinking) in the atmosphere associated with this system will result in dry weather for the foreseeable future. This type of system should also result in sunny and clear weather for the entire week (like it did last week). Unfortunately, this week is somewhat different, due to a cut-off type low pressure system developing over the Canadian Maritime region. This system will sit and spin for several days and, after a sunny day on Tuesday, the counterclockwise flow around the low will begin to spin moisture, in the form of some low clouds, back over New England. This should result in a pretty good cloud cover (mostly cloudy) in eastern New England from Wednesday into Friday. Berkshire County will be on the western edge of this cloud cover but right now it looks like variably cloudy/partly cloudy for those three days (W, Th and F). There is, however, very little risk of any rain on those days, it just won’t be as sunny as we might like.

Temperatures will moderate during the course of the week, with high temperatures generally rising from the low 60s on Tuesday to the mid to upper 60s for Wednesday through Friday. Temperatures will likely reach back up into the unseasonable 70s over the weekend as the cut-off low pulls away and mostly sunny skies return.

The National Weather Service in Albany has issued another frost advisory tonight as frost is likely in many locations with low temperatures in the low to mid 30s. A light wind should persist in many areas, which will likely limit the frost. Frost is most likely in the valleys and low spots over the elevated terrain.

Monday Night

Clear and cold.

There is the risk of frost, particularly in wind sheltered valleys and low spots over the high terrain. Low temperatures generally in the mid 30s, with some low 30s over the elevated terrain.

West-northwesterly winds at 5-10 mph, becoming light (< 5 mph) northwesterly after midnight.

Tuesday

Mostly sunny, breezy and seasonably cool, although slightly milder than Monday.

High temperatures in the low to mid 60s in Pittsfield, North Adams, Adams and Williamstown; mid 60s in Great Barrington and Sheffield and; upper 50s over the elevated terrain and hilltowns.

Northwesterly winds at 10-15 mph with gusts to 20 mph. Winds 10-20 mph with gusts to 25 over the elevated terrain. Winds diminishing toward evening.

Tuesday Night

Generally clear with patchy fog and some scattered low clouds developing toward morning.

Night quite as cold, with low temperatures near 40.

Light northwesterly winds.

Wednesday

Mixed clouds and sun as low-level moisture begins to rotate in around the cut-off low over the Canadian Maritime. There should be more sun than clouds in the morning although there could be a bit more cloud cover developing in the afternoon.

Temperatures will remain seasonable with high temperatures in the mid to upper 60s in Pittsfield, North Adams, Adams and Williamstown; upper 60s in Great Barrington and Sheffield and; low 60s over the elevated terrain and hilltowns.

North-northwesterly winds at 5-10 mph.

Summary: Unfortunately, despite all of the beautiful weather we had during the work week, although not a total washout, this weekend our string of beautiful clear and sunny days will come to an end.

The cloud cover forecast for Saturday is a very tough call, but I will try to give as much detail into my thought process as I can…… Fog should develop in most locations overnight tonight. Once the fog burns off we will be squeezed between the edge of a low cloud bank to our south and east (due to a minor disturbance now off the mid-Atlantic coast being drawn north over New England by a strong southerly flow) and an approaching strong cold front (presently located over the Great Lakes). It is now starting to look like the cloud cover associated with the cold front should hold off for most of the day. If the disturbance stays to our south and east it could turn out to be a fairly sunny and warm day (once the fog burns off) before the clouds from the approaching cold front arrive by late afternoon/early evening. However, there is a pretty good chance that the low cloud bank associated with the disturbance will move over Berkshire County and gives us a pretty cloudy day. In fact, if this occurs, there is even the chance that we could get a few scattered sprinkles or light showers falling out of those low clouds. Right now, I tend to lean toward the second, cloudier, scenario. I will update this if I can tomorrow morning. In any case, at least temperatures will be relatively mild.

A band of rain associated with the advancing cold front will move through late Saturday night, with the bulk of the rain falling between midnight and early Sunday morning. Although the band is relatively narrow, it is moving slowly and will contain some periods of fairly heavy rain. We should get a pretty good dousing, with likely rainfall amounts between 0.50″ and 1.00″. Showers may linger into Sunday morning and even after any rain ends, the low clouds should hang tough into the afternoon. We may see some clearing later in the afternoon on Sunday but it will be breezy and much cooler than previous days.

It still looks like another sunny work week as surface high pressure rebuilds over the Northeast. It will be chilly on Monday, despite sunshine, but temperatures will moderate as the week progresses, probably reaching the 70s again by later in the week.

Friday Night

Clear for a good part of the night with fog developing in many locations toward morning. Fog will be thickest in valley locations.

Low temperatures in the low 50s.

Light south-southeasterly winds.

Saturday

Fog likely burning off during the morning, then variable amounts of cloudiness. Although I think more clouds than sun is most likely (see discussion above) it could turn out to be a fairly sunny and warm day if the cloud bank associated with a weak disturbance stays to our south and east. There is the chance of a few sprinkles/light showers during the afternoon. Probability of precipitation 30%. Any rainfall amounts should be 0.05 inches or less.

It will be relatively mild, although high temperatures will depend heavily on the amount of sunshine. Most likely high temperatures in the low 70s in most locations with some upper 60s over the elevated terrain.

South-southeasterly winds at 10-15 mph.

Saturday Night

Becoming overcast in the evening with rain developing after midnight and continuing, heavy at times, til morning. A few embedded rumbles of thunder are possible (not likely) but there is no risk for severe thunderstorms. Probability of precipitation 90%. Likely rainfall amounts between 0.50″ and 1.00″.

Low temperatures in the upper 50s in most locations with mid 50s over the elevated terrain.

South-southeasterly at 10-15 mph shifting to westerly as the cold front passes near daybreak.

Sunday

The steady rain should end in the early morning although scattered showers are still possible for most of the morning. A low overcast should linger for a good part of the day although there may be some clearing mid to late afternoon. It will be breezy and much cooler than previous days.

Temperatures will not rise much, peaking near 60 in most locations, mid to upper 50s over the elevated terrain. Temperatures will begin to fall through the 50s later in the afternoon.

West-northwesterly winds at 10-15 mph with some higher gusts, particularly over the elevated terrain.

Summary: The autumn pattern which has developed appears likely to continue for the foreseeable future. The surface high pressure system, which has been dominating our weather all week, will hang on for another 1-2 days. Friday should be much like today, with clear skies and warm temperatures. A strong cold front will approach from the west on Saturday. After any fog burns off it should become mostly sunny and mild, with an increase in clouds during the afternoon. A slow moving band of rain/showers associated with the cold front should arrive sometime Saturday evening and continue for a good part of the night. It still appears that the rain/showers may hang on into Sunday morning and the rest of the day will likely be cloudy and much cooler than in recent days. Although the global U.S. model (GFS) has been persistent in keeping it raining in Berkshire County into early Sunday afternoon, the higher resolution NAM model and the European (ECMWF) model have the rain clearing out by daybreak. The ECMWF model even has skies clearing out on Sunday (Go Europe!!). My gut (experience?) tells me that the showers will probably end early but the low cloud cover will linger. I will update this situation with tomorrow’s forecast. In any case, it should become breezy and much cooler on Sunday. As the cold front finally clears the county, there will likely be a return to fair skies as another surface high pressure system builds in and becomes camped over the region for most, if not all, of next week. Monday will probably be the coolest day of the season so far, despite sunny skies, with temperatures in the 50s. The airmass will modify as the week progresses, with temperatures in the 60s most days, and possibly even into the 70s again by late week.

Thursday Night

Clear and calm with seasonably cool temperatures. Fog may develop in a few locations.

Low temperatures in the low to mid 40s countywide.

Calm winds.

Friday

Sunny and continued unseasonably warm.

It will likely even be a few degrees warmer than Thursday, with high temperatures in the mid to upper 70s in Pittsfield, Adams, North Adams and Williamstown; upper 70s in Great Barrington and Sheffield and low to mid 70s over the elevated terrain.

Light southerly winds (< 5 mph) increasing to 5-10 mph during the afternoon.

Friday Night

Generally clear. However, fog and some low clouds will likely develop and become fairly widespread after midnight.

It will be milder with low temperatures near 50.

Winds diminishing and becoming calm.

Saturday

Fog and low clouds should burn off during the morning (I hope fairly quickly). It will likely become mostly sunny for a time late morning into early afternoon. Clouds will increase and thicken as the afternoon progresses, becoming overcast by sunset.

High temperatures are a little uncertain because so much depends on how much sunshine any particular location gets. However, with at least some cloud cover in the offing it should be cooler than recent days, although temperatures should remain mild. Most likely, high temperatures will be in the  low 70s in Pittsfield, Adams, North Adams and Williamstown, low to mid 70s in Great Barrington and Sheffield and upper 60s to near 70 over the elevated terrain and hilltowns depending on elevation.

Light southerly winds early, increasing to 10-15 mph.

Saturday Night and Sunday

Rain and showers developing during the mid to late evening and continuing through most of the night. Probability of precipitation 80%. Rainfall totals around 0.50″. There is a chance for showers early Sunday and low clouds should linger for a good part of the day. It will become breezy and much cooler, with temperatures topping out around 60 during the morning and then holding steady or even dropping into the 50s as the afternoon progresses.

Summary: Surface high pressure will continue to dominate our weather for the next several days. As a result skies will be clear to partly cloudy through Friday with virtually no threat for rain. As the high pressure system moves slowly to our east, the clockwise flow around it will bring warmer air, with a bit more humidity and cloudiness, into the region on southwest winds toward the later part of the week. In fact, temperatures should rise into the 70s Thursday through Saturday, which is several degrees above normal for this time of year (normal high is ~ 67°).

The next wave in the jet stream will bring another cold front through over the weekend, giving us a period of rain and/or showers beginning Saturday evening or overnight Saturday. Unfortunately, it is starting to look as if the front will move very slowly and the rain will likely continue into Sunday as well. Following frontal passage, surface high pressure will again build in, giving us fair weather for most of next week (poor timing, I hope we aren’t getting into one of these repetitive cycles where it rains on the weekend and then is nice all week). Actually, the pattern which we appear to be moving into is a fairly typical (dry) autumn pattern where surface high pressure systems are, only periodically, interrupted by relatively short bursts of rain or showers triggered by cold front passages. The reason this pattern tends to occur in autumn is because the jet stream is still relatively weak, since meridional (north-south) temperature gradients have yet to strengthen (as they will as winter approaches and the sun continues its southward migration). Therefore, waves in the jet stream tend to be flat/shallow and are thus only able to develop weak surface low pressure systems (along the eastern side of the wave trough). This weak surface low pressure tends to track to our north and only drag its trailing cold front over us. This is because the jet stream has begun its southward progression but is still, generally, to our north. Since the air that the cold fronts are lifting is cooler, drier and more stable than in the summer, the cold front passages tend to be drier and lack thunderstorms. Once the jet stream troughs lift back to our north (once the weak wave passes) surface high pressure will build back in until the next weak jet stream wave approaches with the next cold front.

On a more immediate note, it will be clear, calm and dry again tonight so there is, once again, the risk of frost in Berkshire County tonight. I think the frost may be less widespread than last night since dewpoints have risen slightly (into the low 40s). However, the air will be very calm for the entire night (didn’t calm until after midnight last night) so I think we will get enough radiational cooling so that many places will again have frost.

Tuesday Night

Clear, calm and cold.

There is, once again, the risk of frost. Low temperatures in the mid to upper 30s with a few low 30s in some of the colder valley locations.

Calm winds.

Wednesday

Sunny and milder.

High temperatures in the upper 60s in Pittsfield, Adams, North Adams and Williamstown, low 70s in Great Barrington and Sheffield and mid 60s over the elevated terrain and hilltowns.

Light west-southwesterly winds.

Wednesday Night

Clear, calm and seasonably cool.

It will be slightly milder than previous nights with low temperatures near 40 countywide.

Calm winds.

Thursday

Mostly sunny and mild.

High temperatures in the low to mid 70s in Pittsfield, Adams, North Adams and Williamstown, mid 70s in Great Barrington and Sheffield and near 70 to the low 70s over the elevated terrain and hilltowns.

Light west-southwesterly winds in the morning, becoming southwest at 5-10 mph in the afternoon.