Summary: Yesterday’s high temperature of 57 degrees in Pittsfield broke the record for the date by 8 degrees. The old record was 49 set in 1974. That record is rapidly becoming a thing of the past as a strong cold front at the leading edge of a deep trough in the jet stream passed through in the early morning hours. The jet stream wave pattern, now that we are moving into the cold trough, looks like it has decided to stop propagating and is, essentially, becoming what is called a “standing” wave for at least the next several days. Therefore, the western U.S. will remain under a warm ridge and we will be under a cold trough. As a result, it will be relatively cold in Berkshire County, with below normal temperatures, for the foreseeable future.

A strong west-northwesterly flow of cold air circulating between departing surface low pressure on the eastern side of the trough and high pressure on the western side of the trough will make it feel even colder for the next 24-36 hours. This cold wind will also pick up and carry lots of moisture off the Great Lakes into our region so we should remain relatively cloudy with a chance of a lake effect snow shower of flurry from time to time over the next couple of days as well.

Several small disturbances in the jet stream will rotate around the base of the trough through mid-week next week. Most of these will remain weak and well to our south. However, on Sunday, a somewhat stronger disturbance appears likely to generate a surface low pressure system off the Mid-Atlantic Coast. It is likely that we will get light snow accumulations from this system. Right now, it looks like around 1-3″. I will update this tomorrow…..

Thursday Night

Mostly cloudy and breezy. There is a good chance of a lake-effect snow shower or flurry, particularly after midnight. Probability of precipitation 50%. There may be a dusting in places.

Temperatures will not fall considerably due to the cloud cover and because the air is blowing over the relatively mild Great Lakes. Low temperature near 20 in most locations, mid to upper teens over the elevated terrain. Wind chill temperatures falling into the single digits.

Westerly winds at 10-15 mph, 15-20 mph over the elevated terrain with some gusts over 30 mph.

Friday

Mostly cloudy in the morning and into early afternoon with the chance of a lake-effect snow shower of flurry. Probability of precipitation 50%. It may become partly sunny later in the afternoon. It will be quite breezy and cold.

Temperatures will not rise much as even colder air progresses southeast out of Canada. High temperatures in the low 20s in Pittsfield, Adams, North Adams and Williamstown, mid 20s in Great Barrington and Sheffield, and upper teens to near 20 over the elevated terrain and hilltowns. Wind chill temperatures will remain in the single digits.

West-northwesterly winds increasing to 15-20 mph during the afternoon, 20-25 mph over the elevated terrain with higher gusts.

Friday Night

Partly cloudy and cold.

Temperatures will fall as skies partially clear and winds diminish overnight. Low temperatures near 10 in most locations, mid to upper single digits over the elevated terrain. Wind chill temperatures near zero.

West-northwesterly winds at 10-20 mph in the evening, shifting to westerly and diminishing after midnight, becoming relatively light at 5-10 mph by morning.

Saturday

Partly cloudy in the morning, becoming overcast during the afternoon as the disturbance mentioned in the “summary” approaches. Remaining cold. It won’t feel quite as cold as winds will be much lighter than the past 2 days.

High temperatures in the low 20s in Pittsfield, Adams, North Adams and Williamstown, mid 20s in Great Barrington and Sheffield, and upper teens over the elevated terrain and hilltowns.

Southwesterly winds at 5-10 mph.

I apologize for no forecast yesterday. Mondays are difficult as I teach all day and have a lab that runs til late afternoon. I may switch to making my forecasts on Tues, Thurs and Sun….I will let you know.

Summary: We will have a brief warmup through tomorrow and then we will return to seasonable temperatures….

Our amplified jet stream wave pattern is propagating eastward with the warm ridge (jet stream lifted well to our north….think of a mountain “ridge”) peaking over us late tonight and the cold trough (southward dip in the jet stream) which gave the Rockies a pretty good snowstorm yesterday approaching us on Wednesday. Under the ridge, it will be unseasonably warm tonight and Wednesday. The leading edge of the trough will move through as a strong cold front on Wednesday night, giving us a fairly prolonged bout of moderate to heavy rain. Berkshire County will likely see between 0.75″ and 1.25″ of rain with this frontal passage. Combined with melting of the wet snow/ice pack on the ground there could be some minor street and basement flooding.

As the jet stream lifts to our north late this afternoon and this evening a disturbance within the jet stream will give us a short bout of moderate rain showers this evening. Those showers are presently over western New York and into Ontario. It will remain well above freezing tonight. On Wednesday, despite overcast skies, we will likely reach 50 degrees as the dewpoints rise into the mid to upper 40s. Once the cold front passes it will turn windy and much colder on Thursday.

Tuesday Night

Overcast with occasional rain showers this evening, moderate at times, ending by midnight. Spotty drizzle with patchy fog forming after midnight. There could be a few isolated pockets of freezing rain early over the higher elevations. However, temperatures will be very close to freezing so I do not expect any significant problems. Probability of precipitation near 100%. Rainfall totals around 0.25″.

Temperatures in the mid to upper 30s in most locations this evening will begin to rise after midnight and will likely reach the low 40s by morning. Over the elevated terrain, temperatures will be in the low 30s this evening, rising to the upper 30s by morning.

Southeast winds at 5-10 mph, shifting to southerly after midnight.

Wednesday

Patch fog in the morning. Mostly cloudy to overcast skies and unseasonably warm. Showers likely developing during the late afternoon hours. Probability of precipitation rising to 70% by dark. Rainfall totals between 0.10″ and 0.20″.

High temperatures near 50 in Pittsfield, Adams, North Adams and Williamstown, low 50s in Great Barrington and Sheffield, and mid to upper 40s over the elevated terrain and hilltowns.

Southerly winds increasing to 10-15 mph during the afternoon.

Wednesday Night

Rain, moderate to heavy at times, ending between 3 and 7 am. Probability of precipitation 100%. Rainfall totals between 0.75″ and 1.25″.

Temperatures will hold steady, near 50, until the cold front passes shortly after midnight, then temperatures will drop through the 40s, reaching the mid to upper 30s by morning, low 30s over the elevated terrain.

Southerly winds increasing to 15-20 mph in the evening, 20-25 over the higher terrain, with gusts in the 30s. Winds will shift to southwesterly after midnight and westerly by morning.

Thursday

Partly cloudy, windy, and much colder. There is the slight chance of a snow shower in the morning. Probability of precipitation is 20%. No accumulation expected.

Temperatures will hold steady in the 30s in the morning and then fall during the afternoon. By nightfall, temperatures will fall to the upper 20s in Pittsfield, Adams, North Adams and Williamstown, near 30 in Great Barrington and Sheffield, and low to mid 20s over the elevated terrain and hilltowns.

Westerly winds will peak in the late morning to early afternoon at 20-25 mph in lower elevations and 25-30 over the elevated terrain. There will be gusts to 40 mph. Winds will diminish later in the afternoon.

I plan to post forecasts on Monday, Wednesday and Friday afternoons this semester, the same as when student forecasts are being posted in the Introduction to Meteorology course each autumn. However, when active weather is occurring I will post updates on other days. For this reason, I am posting a forecast for Monday since it appears Berkshire County will be receiving frozen precipitation….

Overrunning moisture associated with a warm front is generating a large band of precipitation over the upper Midwest this afternoon. This precipitation should reach us mid-morning tomorrow. Right now the time frame appears to be as follows: A burst of moderate to heavy snow should begin Monday morning around 9 or 10 am. The snow should continue off and on, until mid-afternoon. After the initial burst, the snow should be mostly light to moderate, although an occasional heavy burst could occur. Snowfall totals should be generally in the 1-3″ range with the heaviest amounts over the elevated terrain. Temperatures will be in the teens when the snow begins and should remain in the 20s during the afternoon. The ground is very cold from our recent cold spell so snow should easily accumulate on both grassy surfaces and paved surfaces. I suspect with road treatments the main thoroughfares will just become wet during the afternoon but snow could reaccumulate with any heavier bursts of snow. The snow should change to sleet (ice pellets) during the mid-afternoon, say around 3 pm or so. Sleet will likely continue off and on into the early evening, and possibly end as some freezing rain between 5 and 7 pm. Additional sleet accumulations of around 1/2″ are possible. During the evening, til around midnight, some light freezing rain or freezing drizzle is likely. I am not concerned that this freezing rain/drizzle will cause an icy glaze, as sometimes occurs when the freezing rain occurs suddenly before any other precipitation can impact the roads, because there will already be slush and salt on the roads from the earlier snow and sleet.

Roads should be most treacherous late morning when the snow is falling and temperatures are coldest. Travel could be a little treacherous during the evening commute with some sleet falling and a little slush on the roads. However, it should not be too bad as the precipitation will likely not be too heavy and most roads will have been plowed/salted by that point.

I will try to update this forecast later tonight or tomorrow early am after the evening computer model results are in and the radar can detect the precipitation shield as it approaches us….

Summary: The jet stream wave pattern has become less amplified, allowing the deep cold trough which has been over us for the past few days to flatten out so that the coldest arctic air can begin lifting out of our region. A weak surface low pressure system is zipping by to our south and there is an area of light snow from the northernmost part of its precipitation shield that is moving through the eastern Great Lakes and western NY. This area of light snow will pass through Berkshire County this evening. Accumulations should be very light, from a dusting to as much as an inch over the higher terrain.

After the low passes, and surface high pressure begins to build in, we will have a transitional day on Saturday, as the resulting west-northwest flow between these systems brings in lots of clouds and even the chance of a snow shower off the Great Lakes. Sunday should be a beautiful winter day as high pressure crests over us bringing sunny skies, relatively light winds and seasonably cold temperatures.

Early next week a trough in the jet stream wave pattern will dig in over the western U.S. and a warmer ridge will build over the eastern U.S.. As the surface high from Sunday moves east and the ridge begins to build in on Monday, the leading edge of milder air will lift over the cold air at the surface as a warm front. This will probably bring us some light snow late Monday into Monday night that will likely end as sleet and/or freezing rain overnight Monday. Although precipitation amounts should be very light there is some concern for any freezing rain that falls Monday night since road surfaces are VERY cold from our recent frigid weather. I will update this with Monday’s forecast.

In any case, much milder air will move in behind the warm front for Tuesday and, especially, Wednesday. We may get a bout of heavy rainfall on Thursday as the entire jet stream wave pattern progresses east and the leading edge of the trough from the western U.S. advances on us as a very strong cold front.

Friday Night

Becoming overcast with a period of very light snow likely this evening. The snow should only last a few hours and end by midnight. Probability of precipitation 70%. Accumulations will be very light, with most places only receiving a dusting. There may be as much as 1/2 inch to an inch over a few spots in the higher terrain. It should remain mostly cloudy after the snow ends.

Temperatures will drop in the evening as the precipitation arrives (dewpoints are still very low), but then hold fairly steady after midnight due to the cloud cover. Low temperatures near 10 in Pittsfield, North Adams, Adams and Williamstown, low teens in Great Barrington and Sheffield, and mid to upper single digits in the elevated terrain and hilltowns.

Winds will be light, shifting from west-southwesterly to north-northwesterly after midnight.

Saturday

Partly cloudy in the morning, becoming mostly cloudy in the afternoon. There is the chance of a snow shower or flurry late. Probability of precipitation 30%. No accumulation expected.

It will still be cold, with high temperatures in the mid teens in Pittsfield, mid to upper teens in Adams, North Adams, and Williamstown, upper teens in Great Barrington and Sheffield, and near 10 over the elevated terrain and hilltowns.

Northwest winds at 5-10 mph in the morning, increasing to 10-15 mph in the afternoon.

Saturday Night

Clearing during the evening. Mostly clear after midnight.

It will be cold, with low temperatures in the low to mid single digits, near zero over the elevated terrain.

Northwest wind at 5-10 mph.

Sunday

Mostly sunny and still cold. However, it will be slightly warmer than its been and the bright sun should make it feel downright warm compared to the weather we have had lately.

High temperatures of near 20 in Pittsfield, near 20 to low 20s in Adams, North Adams and Williamstown, low 20s in Great Barrington and Sheffield, and mid to upper teens in the elevated terrain and hilltowns.

Northwest winds at 5-10 mph.

Summary: BRUTAL!! Sorry, that’s the first thing that popped into my head after coming in from outside….

A very deep trough in the jet stream wave pattern continues to be centered over the eastern U.S., allowing arctic air to plummet southward over our region. This air mass will remain centered over us for the next 36 hours or so and we will continue to have very cold temperatures. Tonight will be generally clear. In addition, surface high pressure will crest over the region so winds will become light to calm. These conditions, together with a snow cover and a very low dewpoint (-9 deg right now) will give us very good radiational cooling conditions. As a result, temperatures will plummet overnight to their lowest levels of the season. I expect most locations to bottom out between -5 to -10 although some valley locations, particularly “depressions” and low points in the elevated terrain could drop below -10.

Over the next few days, disturbances in the jet stream will rotate around the base of the trough and generate weak surface lows that will move by to our south and then move northeast off the coast, following the jet stream. On Thursday, a surface low will move by way to our south and we will not even be within its cloud shield. However, this low will impact our weather as it develops off the coast and tightens the pressure gradient over us (between the low and the arctic high just to our northwest) and increase wind speeds considerably. As a result, Thursday will be much like today with very cold temperatures and brutal wind chill temperatures. Temperatures Thursday night should, once again, be below zero but probably not as cold as tonight since a breeze will persist. However, wind chill temperatures will be extremely low.

On Friday, the trough will begin to flatten out a bit, allowing the coldest air to begin to lift out of our region. Temperatures should finally reach the teens (yipee!). Another disturbance will rotate through the base of the trough. However, the slight shift (flattening) in the jet stream will enable the surface low which develops to our south to move closer than the previous one. Even though earlier this week it looked like we would get more significant accumulations from this “storm”, it now looks like the low will be weaker and move quickly out to sea. We will probably only get an inch or two at best Friday night. Surface high pressure will rebuild behind the departing low giving us a tranquil, albeit still cold, weekend. A trough will dig into the western U.S. early next week (snowstorm for the Rockies) and this shift in the jet stream pattern will enable a ridge to develop over the eastern U.S., allowing much milder air to flood into the region. We will likely see temperatures in the 40s by Wednesday. So, if the cold air is getting you down, relief is in sight…..

Wednesday Night

Mostly clear and extremely cold.

Low temperatures will be between -5 and -10 in most locations with a few of the colder valley locations, particularly “depressions” and low points over the elevated terrain between -10 and -15.

West-northwest winds at 5-10 mph this evening, becoming light to calm after midnight.

Thursday

Mostly sunny and very cold. Becoming very breezy, with brutal wind chills, particularly later in the afternoon.

High temperatures will be near 10 in Pittsfield, Adams, North Adams and Williamstown, the low teens in Great Barrington and Sheffield, and mid single digits over the elevated terrain and hilltowns. However, wind chill temperatures will be very low, from -5 to -20.

Northwesterly winds at 5-10 mph early will increase to 10 to 15 mph during the late morning hours. West-northwesterly winds will increase to 15-20 mph during the afternoon, 20-25 mph over the elevated terrain, with gusts of 30-40 mph.

Thursday Night

Mostly clear. There will be an increase in thin mid to high level clouds toward daybreak.

Temperatures will again drop below zero. Low temperatures will likely be between -2 and -8. However, wind chill temperatures will be dangerously low, between -20 and -30 at times.

West-northwesterly winds of 15-20 mph in the evening, decreasing to 10-15 mph after midnight.

Friday

The sun will be dimmed by mid and high level clouds during the morning. Clouds will thicken and lower during the afternoon. There is a chance of a little light snow or a snow shower late. Probability of precipitation 30%. No accumulation expected.

High temperature in the mid teens in Pittsfield, mid to upper teens in Adams, North Adams and Williamstown, upper teens in Great Barrington and Sheffield, and low teens in the elevated terrain and hilltowns.

West-northwesterly winds at 10-15 mph early, diminishing to 5-10 mph late morning to early afternoon and then becoming light later in the afternoon.

Summary: A low amplitude ripple has developed along the polar front, which passed to our south yesterday. A very weak surface low pressure system and associated upward motion in the atmosphere has developed in response to this low amplitude wave in the jet stream, as this wave creates divergence in the wind flow aloft. As the low moves by to our south and out to sea, Berkshire County will see some intermittent light snow develop this afternoon and into this evening. Off and on snow showers will continue through the night as the low pulls away and the west-northwesterly winds behind it (counterclockwise flow around low pressure) begin to generate some lake-effect snow showers. So, essentially, we will see a combination of what we call “system” snow and “lake-effect” snow overnight tonight. All of this snow, no matter what is causing it (and no matter what you call it) will not amount to much in the way of accumulations. Most locations will see accumulations in the 1-2″ range although there could be 3″ in a few spots in the elevated terrain to the east.

Once the surface low pulls away, the northwest flow around the low will pull down even colder arctic air out of Canada for Tuesday through Thursday, the coldest air of the season. High temperatures will probably hold steady in the low teens on Tuesday and will likely not get out of the single digits on Wednesday. Overnight lows will be near zero both Tuesday and Wednesday night. How frigid overnight lows get depends on how much clearing we get and how light the winds get. Right now Wednesday night looks like the coldest night with lows probably below zero. There will be a fairly persistent west-northwesterly breeze so it will feel even more frigid with wind chill temperatures below zero and as much as 10-20 degrees below zero at times.

We still look on track to get a “moderate” snowstorm late Friday into Saturday. At this point it looks like about 3-6″. The wave in the jet stream generating the surface low looks somewhat positively tilted (with a “forward” facing tilt) and progressive (moving quickly) so it looks like a fast moving storm without particularly heavy snow.

Monday Afternoon and Night

Overcast with intermittent light snow developing late this afternoon and continuing through this evening. The snow will become even more intermittent and showery after midnight. Probability of precipitation 90%. Accumulations most likely in the 1-2″ range for most locations although there could be up to 3″ in a few spots over the elevated terrain to the east.

Temperatures will hold near 20 during the evening and then drop after midnight. Low temperatures by morning will be in the low teens in Pittsfield, Adams, North Adams and Williamstown, mid teens in Great Barrington and Sheffield, and upper single digits in the elevated terrain and hilltowns.

Light southerly winds this evening, shifting to west-northwesterly just before midnight and increasing to 10-15 mph after midnight. Winds will increase to 15-20 mph over the elevated terrain with some gusts over 30 mph.

Tuesday

There will be variable amounts of clouds, depending on where the lake-effect snow shower bands set up. On average it will be partly sunny (50-75% cloud cover) to mostly cloudy (75-95%). Skies may clear a bit late in the afternoon. There is a good chance of a snow shower. Probability of precipitation 50% (probability of snow in any given location). Some locations may receive a dusting.

Temperatures will not rise much and it will feel even colder with a stiff west-northwesterly breeze. High temperature in the low to mid teens in Pittsfield, Adams, North Adams and Williamstown, mid teen in Great Barrington and Sheffield, and near 10 in the elevated terrain and hilltowns. Wind chill temperatures will be in the single digits below zero at times.

West-northwesterly winds at 10-15 mph, 15-20 mph over the elevated terrain with higher gusts.

Tuesday Night

Becoming partly cloudy. There is still the chance of a snow shower, mostly during the evening. Probability of precipitation 30%.

Low temperatures will fall to near zero in most locations, with 0 to -5 degrees in the elevated terrain and hilltowns. Wind chill temperatures -10 to -15 at times.

West-northwesterly winds will lighten up a bit and will average around 5-10 mph in most locations.

Wednesday

Partly to mostly cloudy, breezy and frigid.

High temperature in the upper single digits in Pittsfield, Adams, North Adams and Williamstown, near 10 in Great Barrington and Sheffield, and low to mid single digits in the elevated terrain and hilltowns. Wind chill temperatures from -10 to -20 at times.

West-northwesterly winds at 10-15 mph, 15-20 mph in the elevated terrain with higher gusts.

Summary: If you liked today’s weather then you are sure to love the forecast for next week…..

As surface high pressure moves to our east on Saturday, the “return” southerly flow will bring us a brief warm up Saturday into early Sunday before arctic air returns for the majority of the the workweek. An Alberta Clipper low will scoot by to our north on Sunday and drag its trailing arctic cold front across the region, opening the door for an Arctic air mass, presently over central and western Canada, to plunge into the Northeast. The frontal passage will likely be accompanied by some scattered snow showers and snow squalls. Then, as the surface high pressure system builds in from Canada behind the front, the cold westerly and northwesterly flow being generated as this high advances will produce a fairly prolonged period of lake-effect snow in western and central NY that could reach us with a few snow showers. We could see an inch or two in places, however, I do not expect much in the way of accumulating snow from either of these events.

High temperatures should be in the teens at best from Monday through Thursday, with low temperatures generally in the low single digits. Winds will be strong early in the week and wind chills may drop to 10 to 20 below at night. The high pressure system will crest over the area on Wednesday and Thursday and conditions will remain very cold but more tranquil than Monday and Tuesday. Low temperatures may drop below zero on Tuesday and Wednesday night, however, radiational cooling conditions will not be ideal with a breeze and some cloud cover on Tuesday night. The best bet for frigid temperatures appears to be Wednesday night as the surface high crests over the region and skies clear and winds die down.

Low pressure should return on Friday. It is too early to tell whether we will get mixed precipitation or snow from this low.

Friday Night

Increasing clouds this evening, becoming overcast after midnight.

Temperatures will fall under clear skies in the evening into the low teens in Pittsfield, mid teens in Adams, North Adams, Williamstown, Great Barrington and Sheffield, and into the upper single digits in the elevated terrain. As clouds move in and the south-southwesterly breeze picks up overnight temperatures will rise, so that by daybreak temperatures should be near 20 to the low 20s in most locations.

South-southwesterly winds at 5-10 mph this evening, increasing to 10-15 mph after midnight.

Saturday

Mostly cloudy in the morning, becoming partly cloudy in the afternoon. It will be breezy and much milder.

High temperatures should be in the upper 30s in Pittsfield, near 40 in Adams, North Adams, Williamstown, Great Barrington and Sheffield, and mid to upper 30s over the elevated terrain and hilltowns.

South-southwesterly winds at 10-15 mph.

Saturday Night

Becoming mostly cloudy. There is the chance of a snow shower toward daybreak as the cold front approaches. Probability of precipitation 30%.

Temperatures will not drop much with significant cloud cover and a south-southwesterly breeze. Low temperatures should be in the low 30s in most locations, near 30 in the elevated terrain and hilltowns.

South-southwesterly winds at 10-15 mph.

Sunday

Mostly cloudy, windy and turning colder, particularly during the afternoon. There is the chance of a snow shower or squall during the morning as the cold front passes through and then a chance of a lake-effect snow shower toward evening. Probability of precipitation 40%. There will likely be a dusting in places. A few isolated locations, particularly over the elevated terrain could see as much as a half inch or so.

High temperatures of low to mid 30s will occur early and then temperatures will begin to drop as the cold front passes during the morning. Temperatures will fall through the 20s during the afternoon.

South-southwesterly winds of 10-15 mph early, shifting to west-northwesterly during the morning hours. Wind speeds will increase with the wind shift to 15-20 mph with 20-25 mph over the elevated terrain. There will likely by gusts to 30-40 mph with the frontal passage.

Summary: It looks like our early January thaw is coming to an end. The polar front has moved through and is now stalled to our south in a southwest to northeast orientation. A surface low pressure system has developed along the front and is moving northeast toward our region. From last week til a few days ago it looked like this storm would pass well to our south. However, I have noticed that the computer models in the past year or two have had a southern bias to the storm tracks initially, with the track shifting north over time. I believe this is due to the recent warming of our climate system which is not ingrained into the model’s parameterization (approximation) schemes yet.

In any case, it now looks like we will get a bit of a snow “storm” late tonight and tomorrow. The snow should spread over the county from south to north around 4 or 5 am. There will likely be 1-2″ accumulation by 7 or 8 am. The snow will continue off and on for most of the day. It will be mostly light but there are likely to be a few moderate bursts in some areas. The snow should end around nightfall. Total accumulations should be in the 3-6″ range in most locations. However, as per usual, there may be totals in the hilltowns, particularly to the southeast that could reach 7 or 8″. The precipitation should remain snow for the vast majority of the county. There is a slight chance that some sleet or freezing rain could mix in during the day tomorrow in the southernmost parts of the county (i.e. from Sheffield south).

It will then turn seasonably cold but quiet, with nothing more than a few lake effect snow showers for Thursday and Friday. It will be a bit milder on Saturday and early Sunday (highs in the 30s on Saturday) before an Alberta Clipper scoots by to our north on Sunday and drags an arctic cold front through. This may lead to some arctic cold early next week.

Tuesday Night

Clouds lowering and thickening with snow developing from south to north in the early morning hours, around 4 or 5 am. Probability of precipitation near 100%. Snowfall accumulations an inch or two by the morning commute.

Low temperatures in the mid 20s for most locations, with low 20s over the elevated terrain and hilltowns.

Light northwesterly winds shifting to easterly after midnight.

Wednesday

Occasional light snow, with a few moderate bursts in places, ending by nightfall. Probability of precipitation 100%. An additional snowfall accumulation of 2-4″ is likely. Total snowfall accumulations of 3-6″, with the least in the valleys, particularly to the south, where temperatures will be milder, and the most in the higher terrain. There could be some isolated 7 or 8″ totals in the elevated terrain and hilltowns.

High temperatures should be in the upper 20s in Pittsfield, near 30 in Adams, North Adams and Williamstown, low 30s in Great Barrington and Sheffield, and mid to upper 20s over the elevated terrain and hilltowns.

Light east-northeasterly winds.

Wednesday Night

Overcast in the evening with partial clearing after midnight. There is the slight chance of a lake-effect snow shower or flurry toward morning. Probability of precipitation 20%.

Temperatures will not drop much with significant cloud cover and a west-southwesterly breeze. Low temperatures should be in the mid 20s in most locations, mid to upper 20s to the south, and low 20s in the elevated terrain and hilltowns.

Southwesterly winds at 5-10 mph in the evening, shifting to westerly and increasing to 10-15 mph after midnight.

Thursday

Variably cloudy (will average out partly to mostly cloudy), and seasonably cold with a cold west-northwesterly breeze. There is the slight chance of a lake-effect snow shower or flurry in the morning. Probability of precipitation 20%.

High temperatures near 30 in Pittsfield, Adams, North Adams and Williamstown, low 30s in Great Barrington and Sheffield, and mid 20s over the elevated terrain and hilltowns.

Westerly winds in the morning shifting to northwesterly in the afternoon. Wind speeds of 10-15 mph with 15-20 mph over the elevated terrain.

Summary: A warm front is lifting through the region this afternoon and evening with a few bands of rain showers. The last of these, and what appears to be the heaviest should move through early this evening. Temperatures are above freezing in most locations, however, temperatures are at or slightly below freezing over the higher terrain (e.g. Peru at 30 deg.) so watch out for some slick spots (mostly on walks and driveways) in those locations this evening. After the early evening band of rain there should only be a few lingering light showers or spotty drizzle for the rest of the overnight. Temperatures will rise above freezing in all locations by midnight as milder and more humid air moves in behind the front.

The warm front passage will open the door to an unseasonably mild weekend. Unfortunately, the subtropical airmass moving in behind the front also has a high moisture content. Therefore, low clouds will be quite stubborn and difficult for the low sun-angle to burn off both weekend days. Therefore, we should remain mostly cloudy with only some occasional breaks in the overcast. The best chance for sunshine is late on Saturday and during the late morning and early afternoon on Sunday. Despite the lack of sunshine, temperatures should still reach the 40s on Saturday and even the 50s in most locations on Sunday.

There is the slight chance of a few stray showers late on Sunday afternoon as the cold front at the leading edge of a cold trough in the jet stream advances eastward. This front should pass through with some showers Sunday night with a return to more seasonable temperatures but relatively dry weather early next week. It should still be relatively mild on Monday as we transition to the cooler polar airmass behind the front. A weak low developing along the front on Monday looks like it will pass out to sea well to our south. For you snow lovers and winter sports enthusiasts I don’t see anything to suggest any significant snowstorms for us, even in the long-range models. The snow cover will get wet this weekend and then, unfortunately, freeze solid next week…..

Friday Night

Overcast with  occasional rain showers this evening, mostly during the early evening. There may be a few isolated pockets of freezing rain over the elevated terrain. However, temperatures are over 30 degrees everywhere so there shouldn’t be much ice buildup. Watch for slick spots on walks and driveways in particular. Showers should taper off late this evening and there should only be a few scattered light showers and spotty drizzle after midnight. Probability of precipitation 100%. Rainfall totals generally around 0.10″.

Temperatures will rise a few degrees overnight to near 40 in Great Barrington and Sheffield, mid to upper 30s in Pittsfield, North Adams, Adams and Williamstown, and low to mid 30s over the elevated terrain and hilltowns.

Light southeasterly winds shifting to southerly after midnight.

Saturday

It will average out mostly cloudy, with a stubborn low cloud cover, and unseasonably mild. It will likely be overcast in the morning with some more peeks of sun during the afternoon but it will be difficult for the sun, at such a low angle this time of year, to “burn off” (evaporate) these clouds.

High temperatures should be in the low 40s in Pittsfield, Adams, North Adams and Williamstown, low to mid 40s in Great Barrington and Sheffield, and near 40 over the elevated terrain and hilltowns. Should the sun make an unexpected, more prolonged appearance in the afternoon, add a few degrees to these highs.

Light southerly winds.

Saturday Night

Overcast and unseasonably mild. Fog may develop over the snowpack in some locations. There could be some spotty light drizzle.

Temperatures will not drop much with the low cloud cover and humid airmass. Expect temperatures to bottom out in the upper 30s to near 40 in most locations.

Light southerly winds.

Sunday

Overcast early with some patchy fog and spotty drizzle. As the day progresses we should see a few breaks in the overcast. There is the slight chance of a shower during the late afternoon. Probability of precipitation 20%. It will be very mild for this time of year.

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

Southerly winds increasing to 8-12 mph.

Summary: A weak cold front moved through this afternoon accompanied by overcast skies but nothing more than a few sprinkles of rain. A surface high pressure system will build in behind the front and give us clearing skies tonight and a mostly sunny day tomorrow. However, the airmass associated with this system is actually of subtropical origin so temperatures will remain above normal tomorrow, although a stiff northwesterly breeze will make it feel colder.

The jet stream wave pattern will become more amplified over the next few days with a trough of cold arctic air digging southward over the western U.S. and a warm ridge of subtropical air building north over the eastern U.S. The southern dip in the jet stream will pick-up a weakening cut-off low pressure system, presently meandering over Texas, and lift it through the center of the country and into the Great Lakes region by Friday. As the subtropical surface high pressure system moves to our east Thursday night, the southerly flow on its western side (clockwise flow around high pressure) will push the warm front extending eastward from the dissipating cut-off low through our region. This frontal passage will be accompanied by some scattered rain showers, but nothing too significant. Believe it or not, this will allow even warmer air to flood into the region over the weekend. We could even see 50 degrees at some point. The record high temperature for Pittsfield is 57 for both weekend days but I think, at this point, that those records are fairly safe.

The entire jet stream wave pattern will progress slowly eastward and the eastern edge of the cold trough (polar front) may finally move through our region as a cold front on Monday. This will allow more seasonable temperatures to move back in. The long-range models are suggesting that a weak surface low could form along the polar front to our south on Wednesday. It is still very early to evaluate this situation, however, right now it looks like the jet stream will have flattened out considerably by then so the low should be weak and progress rapidly eastward.

Wednesday Night

Mostly clear and becoming breezy.

Despite the colder air moving in and clear skies, the strong breeze will not permit much radiational cooling. Low temperatures will likely bottom out in the mid to upper 20s in most locations with low to mid 20s in the elevated terrain and hilltowns.

Winds shifting to the west-northwest in the evening and increasing to 15-20 mph by midnight, 20-25 mph over the elevated terrain. Some gusts to 30-35 mph are likely. Winds will begin to diminish a little by daybreak.

Thursday

Mostly sunny. Temperatures will be slightly above normal, however, a stiff northwest breeze will make it feel much colder than the thermometer reading.

High temperatures should be in the mid to upper 30s in Pittsfield, Adams, North Adams and Williamstown, upper 30s in Great Barrington and Sheffield, and low to mid 30s over the elevated terrain and hilltowns.

Northwest winds at 10-15 mph, 15-20 mph over the elevated terrain will become light late.

Thursday Night

Clear, calm and seasonably cold, with some increase in clouds toward daybreak.

It should be a good radiational cooling night with clear skies, calm winds and a snow cover. Expect temperatures to drop into the teens throughout the county with mid to upper teens in the elevated terrain and low teens in the valleys.

Calm winds.

Friday

Increasing and thickening clouds in the morning. Overcast with a good chance of a few scattered rain showers in the afternoon. Probability of precipitation 50%. Rainfall totals should be less than 0.10 inches.

High temperatures in the upper 30s in Pittsfield, Adams, North Adams and Williamstown, near 40 in Great Barrington and Sheffield, and mid 30s over the elevated terrain and hilltowns.

Southerly winds at 5-10 mph.