Snowfall totals look to be a bit higher than forecast yesterday. I now expect snowfall totals to be 6-10″ by evening and 8-14″ total.

An update for tomorrow’s snowstorm:

It looks like the snow may arrive slightly earlier than it appeared yesterday. Otherwise, there is not much change. Snow should develop from south to north across the county sometime between 7 and 9 am. Snow will then continue throughout the day and into the evening. The snow will vary somewhat in intensity but will be heavy at times, particularly during the afternoon. Snow will begin to taper off during the evening and then end sometime around midnight, to as late as 2 am. It still appears that likely snowfall totals will be 6-12″ with the greatest amounts in the elevated terrain to the east in central and southern Berkshire. I am basing my totals predominantly on the European model which has been pretty consistent with this storm. However, the U.S. models have been making the storm “wetter” and wetter the last few runs. If those models are correct, we could end up with a widespread 12-16″. However, I am inclined to believe that 6-12″ is more likely. I will post again if I see a distinct change in the situation with tonight’s model runs.

Tuesday Night

Increasing clouds and turning colder, with a chance of light snow or a snow shower toward morning. Probability of precipitation 30%. No accumulation expected.

Low temperatures near 30.

West-northwesterly winds at 5-10 mph, becoming light north-northwesterly after midnight.

Wednesday

Snow developing from south to north between 7 and 9 am and then continuing, heavy at times, throughout the day. Becoming breezy during the afternoon. Probability of precipitation near 100%. Likely snowfall totals by evening 4-8″.

Temperatures holding fairly steady, or even falling a few degrees, throughout the day, in the upper 20s in Pittsfield, Lee, Stockbridge, Adams, North Adams, and Williamstown; near 30 in Great Barrington and Sheffield and; mid to upper 20s over the elevated terrain.

Northeasterly winds at 5-10 mph during the morning, becoming northerly at 10-15 mph during the afternoon.

Wednesday Night

Snow during the evening, tapering off and then ending sometime around midnight to 2 am. It will be cold and breezy. Probability of precipitation 80%. Likely total snowfall accumulations 6-12″, with the greatest amounts over the elevated terrain to the east in central and southern Berkshire.

Low temperatures in the low to mid 20s.

Northerly winds at 10-15 mph in the evening, shifting to northwesterly after midnight.

Thursday

Mostly cloudy and cold.

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

Northwesterly winds at 5-10 mph.

The following forecast is provided by Kim Grahn and Nick Staffin  as part of lab work for the Introduction to Meteorology course (ATM-145) under faculty (Joe Kravitz) supervision. The forecast discussion is mine (JK) ……

Unfortunately for anyone hoping to travel for Thanksgiving, it looks like Berkshire County, as well as a good portion of the Northeast, is in for a significant snowstorm on Wednesday. Unlike some coastal storms, this is a fairly high confidence forecast. It is unlikely that the storm will miss us completely, or change to rain. My best estimate 48 hours out is that we will see a fairly widespread 6-12″ accumulation, with the heaviest amounts over the elevated terrain in central and southern Berkshire.  Snow will likely spread from south to north across the county Wednesday morning, in the 8-11 am period, and then continue, heavy at times, through the afternoon and into the evening, tapering off in intensity during the evening hours, and then ending by midnight, or shortly thereafter. This will be a fairly quick moving storm, but it will be potent, with snow falling at an inch per hour at times.

As a curiosity to those interested in such things, the European model (ECMWF) has been incredibly consistent since Friday night with the track and intensity of this storm. The U.S. models were all over the place until coming into line with the European model between Sunday and Monday…..

The surface low that dragged its moisture laden warm front through here late last night and this morning has moved northward into northwestern Quebec. We are now, briefly in the “warm quadrant” of this storm until the cold front trailing southward from the low inches through here during the day on Tuesday. Tuesday will remain fairly mild but not as warm as today. As the cold front, which signals the leading edge of another cold trough in the jet stream wave pattern, moves through, it will stall just off the coast Tuesday night. A surface low pressure system will then develop along the front, just off the Southeast Coast, overnight Tuesday. It will then move rapidly northeastward along the front and intensify during the day on Wednesday, reaching Cape Cod by Wednesday evening, and then into the Canadian Maritime region overnight Wednesday.

After the low pulls out, the cold trough will move slowly eastward, becoming centered over our region by Friday morning. Therefore, cold will return for Thursday and Friday. High temperatures will likely remain in the 20s both days, with lows Thursday night in the teens. With a fresh snow cover an clearing skies, temperatures could drop into the single digits by Saturday morning. Temperatures should then moderate over the weekend with temperatures back in the 40s by Sunday.

I will update the forecast for Wednesday’s storm tomorrow afternoon……

Monday Night

Clearing, except for a veil of high, thin clouds. Unseasonably mild.

Low temperatures in the mid 40s.

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

Tuesday

Sunshine through a veil of high, thin clouds.

Temperatures holding fairly steady throughout the day, with high temperatures in the upper 40s in Pittsfield, Lee, Stockbridge, Adams, North Adams, and Williamstown; near 50 in Great Barrington and Sheffield and; mid 40s over the elevated terrain.

West-southwesterly winds at 8-12 mph.

Tuesday Night

Increasing clouds and colder, becoming overcast by morning.

Low temperatures near 30, upper 20s over the elevated terrain.

Westerly winds at 5-10 mph, becoming light northwesterly after midnight.

Wendesday

Snow developing from south to north across the county during the morning, most likely during the 8-11 am time period. Snow, heavy at times through the afternoon and into the evening, tapering off during the evening and ending around midnight or during the early morning hours. Probability of precipitation 90%. Widespread snow accumulation of 6-12″ likely.

High temperatures in the low 30s early in Pittsfield, Lee and Stockbridge, Adams, North Adams and Williamstown; low to mid 30s in Great Barrington and Sheffield and; near 30 over the elevated terrain. Once snow develops temperatures will likely fall into the upper 20s, mid 20s over the elevated terrain.

Light northwesterly winds in the morning, shifting to north-northeasterly and increasing to 5-10 mph in the afternoon.

The following forecast is provided by Ryan Mercer as part of lab work for the Introduction to Meteorology course (ATM-145) under faculty (Joe Kravitz) supervision. The forecast discussion is mine (JK) ……

The cold trough in the jet stream wave pattern centered over our region will, finally, lift out and allow warmer air south of the jet stream to work its way in, as a ridge builds over us for Sunday and Monday. Surface high pressure will crest to our south tonight and then begin to move off the coast during the day on Saturday. As a result, we will have fair skies tonight and Saturday, with slightly milder temperatures on Saturday. A weak warm front, extending well to the east from a surface low pressure system in the northern Great Plains will lift slowly through Berkshire County late Saturday afternoon and Saturday night. This will result in occasional light scattered showers. Things could get a little tricky as temperatures will likely be around or just below freezing at the surface over a good part of the county, particularly over the elevated terrain until about midnight, when the front finally pushes through and temperatures rise above freezing. Therefore, the precipitation is likely to be sleet and freezing rain for a time during the evening. Even though temperatures will be close to freezing and the precipitation will be light, the ground is probably below freezing given how cold it has been. Therefore it won’t take much freezing rain to create some slippery spots.

After the front passes, it will be milder on Sunday, with a mix of clouds and sun and temperatures in the 40s. Meanwhile, a stronger surface low pressure system moving north from the Gulf Coast will merge with the one moving east from the Great Plains and move through the Great Lakes Sunday night. This stronger low will drag another warm front through here after midnight Sunday and into Monday morning. We will see a period of heavier rain with this stronger front, on the order of 0.50″, and this precipitation will be all rain, with temperatures well above freezing. After the front passes through on Monday, temperatures will soar to near 60 degrees. 

On Tuesday, the cold front trailing south from the surface low departing into Canada will begin to move slowly east as another amplified trough in the jet stream moves back over us with colder air for Wednesday through Friday. As the cold front moves through on Wednesday, a surface low pressure system will develop along it, off the Mid-Atlantic coast, and move northeastward. The European model has been bringing this low close enough to the coast that we see a few inches of snow here on Wednesday but the U.S. long-range model (GFS) has it further off the coast, so that we don’t get any precipitation. I will update this situation on Monday…….

Friday Night

Mostly clear and cold. 

Low temperatures in the mid teens, low teens over the elevated terrain.

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

Saturday

Mostly sunny in the morning, increasing cloudiness with the chance of a light sleet or freezing rain shower late. Probability of precipitation 30%. 

High temperatures in the mid 30s in Pittsfield, Lee, Stockbridge, Adams, North Adams, and Williamstown; mid to upper 30s in Great Barrington and Sheffield and; low 30s over the elevated terrain. However, temperatures will fall back to near freezing after sunset.

Southwesterly winds at 5-10 mph.

Saturday Night

Cloudy with occasional, scattered light showers likely. The precipitation should fall as sleet and then freezing rain during the evening and then change to plain rain after midnight. Probability of precipitation 60%. Likely rainfall totals around 0.10″.

Temperatures will be at or just below freezing in the lower elevations before midnight and upper 20s to near 30 over the elevated terrain. Temperatures should rise above freezing everywhere after midnight.

Southwesterly winds at 5-10 mph, becoming light after midnight.

Sunday

A mix of clouds and sun and milder. There is likely to be more clouds than sun to the north and more sun than clouds to the south.

High temperatures in the mid to upper 40s in Pittsfield, Lee and Stockbridge, Adams, North Adams and Williamstown; upper 40s in Great Barrington and Sheffield and; low to mid 40s over the elevated terrain. 

Light southwesterly winds, shifting to southerly in the afternoon.

Sunday Night and Monday

Increasing cloudiness Sunday evening with rain developing just after midnight and continuing into Monday morning. Rain should taper off by mid-morning. Low clouds and some occasional sprinkles and drizzle will likely persist into the afternoon. Overnight lows near 40 will occur in the evening, with temperatures rising through the 40s after midnight. Highs on Monday in the mid to upper 50s.

The standing, amplified jet stream wave pattern persists, with a ridge over the eastern Pacific and western North America and a trough over central and eastern North America. This is permitting unusually cold arctic air over the central to eastern U.S. to be repeatedly reinforced as cold arctic pools of air slide south into the base of the trough. This pattern has persisted since last week. One of these pools of arctic air is residing over us today and tomorrow. As this unusually cold air flows over the still warm Great Lakes on strong westerly winds a band of heavy lake-effect snow is being generated and persisting to the south of Buffalo. Four feet of snow have already fallen and up to six feet may fall by the time winds shift and weaken tomorrow.

The next reinforcing shot of arctic air will be moving in from Thursday night into Saturday. Then it looks like the pattern will change, at least temporarily, as the trough lifts out on Saturday, the jet stream pattern flattens out (becomes zonally [west to east] oriented) and a milder ridge builds in for Sunday and Monday. Temperatures will likely reach the 50s on Monday. However, it looks like the cold trough may re-establish itself over the eastern U.S. again by mid-week next week.

It will be quite cold tonight, with temperatures falling into the low to mid teens with wind chills near zero. However, the strong westerly winds will limit radiational cooling and keep us from getting anywhere near the record low temperature of 6° F. Surface high pressure will build in from the south tomorrow and this will keep skies mostly sunny but it will remain unseasonably cold despite the sunshine. There is the chance for a few snow showers Wednesday evening as a weak “warm” front moves through the county. This warm front is extending eastward from a weak surface low pressure center being generated over the Great Lakes by the next pool of arctic air diving into the base of the trough. Once the warm front moves through it will be slightly milder on Thursday with temperatures rising into the 30s. However, as the surface low in the Great Lakes rides northeast along the eastern edge of the trough it will drag its trailing cold front through here during the day on Thursday. The frontal passage will not generate any precipitation but temperatures will, once again, drop down into the teens Thursday night and only rise into the 20s on Friday.

Tuesday Night

Mostly clear, breezy and unseasonably cold.

Low temperatures in the mid teens, low teens over the elevated terrain and mid to upper teens in South County. Wind chills in the single digits.

West-southwesterly winds at 10-15 mph with gusts 20-25 mph.

Wednesday

Mostly sunny and continued cold but with diminishing winds.

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

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

Wednesday Night

Becoming overcast with a chance of a snow shower in the evening. The greatest chance will be in North County. Clearing skies after midnight. Probability of precipitation 30%. A dusting of snow is possible in a few spots, predominantly in North County.

Low temperatures near 20.

South-southwesterly winds at 5-10 mph.

Thursday

Mostly sunny in the morning, a mix of sun and clouds in the afternoon. Slightly milder than previous days.

High temperatures in the low to mid 30s in Pittsfield, Lee, Stockbridge, Adams, North Adams and Williamstown; mid 30s in Great Barrington and Sheffield and; near 30 to low 30s over the elevated terrain.

South-southwesterly winds at 5-10 mph in the morning, shifting to west-southwesterly and then westerly during the afternoon.

The forecast for the upcoming “storm” has not changed greatly from Friday. However, I would like to give a detailed forecast for the timeline of events as I see it…..

It looks like the precipitation should move in a little earlier than it appeared a few days ago, with snow developing from south to north between 1 and 3 am tonight. It looks like we should get a quick “burst” of snow that lasts for an hour or two, which then changes to rain and freezing rain between about 3 and 6 am from south to north. It looks like we should get a fairly widespread snow accumulation of around 1″ with perhaps only a coating in parts of South County where the changeover to liquid precipitation will likely occur sooner. There could be as much as 2″ in a few spots over the elevated terrain, in North County in particular. There most likely will only be intermittent light rain and freezing rain or drizzle from between around 6 or 7 am til around 9 or 10 am. Temperatures should remain fairly close to freezing during this period. It will likely be at or just above freezing in the lower elevations and at, or just below freezing in spots over the elevated terrain. I suspect the roads during the morning will just have a bit of slush on them due to the combination of snow with a little freezing rain on top over the elevated terrain and they may just be wet if the road surfaces are treated, which I suspect they will be given the “Winter Weather Advisory” which has been issued by the National Weather Service. At lower elevations the main roads will probably just be wet, with a little slush on the secondary roads. Given that snow will fall first, it is unlikely that an icy glaze will form, particularly this early in the season, even though it has been quite cold lately.

The precipitation should change to plain rain everywhere in the county by noon or 1 pm and temperatures will likely rise into the 40s from late afternoon into the evening. Rain will fall, moderate at times, from late morning through late afternoon, and then taper off and end during the evening. Temperatures will begin to plummet late in the evening, once the surface low passes and drags its cold front through. However, precipitation should end well before temperatures fall back below freezing. Hopefully, roads will have a chance to dry a good deal before the drop in temperatures but there could be some icy spots on Tuesday morning. A band of lake-effect snow showers will likely set up over the county on Tuesday morning so there could be a dusting of snow in spots as well. However, the main story for Tuesday, and on through Wednesday as well, will be the unusual cold for this time of year. Temperatures should hold steady in the 20s during the day on Tuesday, with winds picking up to 15-25 mph. During the afternoon, the temperatures will begin to fall through the 20s and into the teens by evening with wind chill temperatures falling into the single digits.

Sunday Night

Overcast with snow developing from south to north between about 1 and 3 am. A quick “burst” of snow is likely before a changeover to rain and freezing rain from south to north between about 3 and 6 am. Rain, freezing rain and/or drizzle becoming light and intermittent by 7 am. Probability of precipitation 90%. Likely snowfall totals before the changeover generally about 1″ with only a coating in some parts of South County and as much as 2″ in spots over the elevated terrain in central and northern Berkshire. 0.10″ or less of icing.

Low temperatures in the upper 20s.

Light south-southwesterly winds, shifting to east-southeasterly after midnight.

Monday

Light and intermittent rain, freezing rain and drizzle until between about 9 and 11 am. Temperatures will be close to freezing, likely at or just above in the lower elevations and at or just below over the elevated terrain during this period. Rain becoming moderate at times from late morning through the remainder of the day. Precipitation becoming plain rain countywide by early afternoon. Probability of precipitation near 100%. Likely rainfall totals around 0.50″. Up to 0.10″ of icing possible in spots over the elevated terrain.

Temperatures near freezing during the morning, rising through the 30s and into the 40s during the afternoon and into the evening.

East-southeasterly winds at 5-10 mph, shifting to south-southwesterly during the afternoon.

Monday Night

A few lingering rain showers and mild during the evening, then mostly cloudy, becoming breezy and sharply colder. A few scattered snow showers and flurries are possible after midnight. There could be a dusting in spots.

Low temperatures in the mid 20s, low 20s over the elevated terrain.

West-southwesterly winds at 5-10 mph early becoming west-northwesterly and increasing to 10-15 mph after midnight.

Tuesday

More clouds than sun, windy and unseasonably cold. A few scattered snow showers and flurries are possible in the morning. Probability of precipitation 30%. There could be a dusting in spots.

Temperatures will hold steady into the afternoon with high temperatures in the mid 20s in Pittsfield, Lee, Stockbridge, Adams, North Adams and Williamstown; mid to upper 20s in Great Barrington and Sheffield and; low 20s over the elevated terrain. Temperatures will fall through the 20s over the course of the afternoon and into the teens by evening with wind chill temperatures falling into the single digits.

Westerly winds at 10-20 mph, with gusts to 30-35 mph.

 

There is no student forecast today…..

The tail end of some lake-effect snow bands will rotate north to through the county this evening. These will give us nothing more than the chance of a few scattered flurries/light snow showers. After these pass through, skies will begin to clear overnight as a sprawling surface high pressure system presently centered over the Midwest, moves eastward and becomes centered over the East Coast during the day on Saturday. This will result in a good amount of sunshine but unseasonably cold temperatures for Saturday.

As the surface high moves to our east Saturday night and Sunday, southwesterly flow around the backside of the high will drive warmer air from the south up and over the cold air here at the surface. This broad area of rising air will result in a building cloud cover later Saturday night and a mostly cloudy day on Sunday. Essentially, what will be happening is that the polar front, which passed through our area as a cold front last night, will begin moving back to the north as a warm front. It will be slightly milder Sunday, but temperatures will still be below average.

In the meantime, as the broad, unseasonably cold, trough in the jet stream wave pattern that has been covering a good part of North America, begins to flatten out over the weekend (why the front is moving back to the north) and temperatures moderate, a bit, across the country, another pool of arctic air will begin to descend southward into the base of the trough. This pool of cold air will plunge into the base of the trough over the central U.S. on Sunday and Sunday night. This will serve to amplify the trough and develop surface low pressure along the Gulf Coast, along the southeastern edge of the trough Sunday night. This surface low will then ride rapidly northeastward along the stalled polar front directly toward Berkshire County during the day on Monday. Right now, it looks like the low will pass directly over southern New England and into the Gulf of Maine by Monday night. With this track, the low will likely draw enough “overriding” warm air (aloft) inland to turn the majority of precipitation to liquid form.

The most likely scenario for this “storm” is that snow will develop sometime Monday morning. We may get an inch or two (or three) of snow before it changes to freezing rain and then rain during the afternoon. Rain should end during the evening hours. There could be enough cold air locked in at the surface that freezing rain may persist for awhile during the afternoon, particularly over the elevated terrain to the north, so that will be something to keep an eye on. I will try to update this forecast on Sunday…..

After the low passes, the cold pool previously discussed, will shift eastward, becoming centered just to our west on Tuesday. In addition, the low which passed through on Monday will intensify as it moves into the Canadian Maritime region. The strong pressure gradient between this departing low and strong high pressure building into the eastern U.S. will generate very strong winds over us. Bottom line….if you think this is bad, wait until Tuesday and Wednesday, when we are likely to see lows in the teens and highs in the 20s and wind chills in the single digits (help!! its too early for this….).

Friday Night

Chance of a few scattered snow flurries this evening, particularly in central and northern Berkshire. Scattered flurries could persist past midnight in North County. Probability of precipitation 30%.  No accumulation expected. Clearing skies after midnight in South County and partial clearing to the north.

Low temperatures near 20, upper teens over the elevated terrain.

West-northwesterly winds at 5-10 mph this evening, becoming light.

Saturday

Mostly sunny but cold.

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

West-northwesterly winds at 5-10 mph.

Saturday Night

Mostly clear in the evening, then increasing clouds after midnight.

Low temperatures in the low to mid 20s.

Light westerly winds becoming southwesterly after midnight.

Sunday

Although there may be a few sunnier periods, particularly during the mid to late morning, skies should be mostly cloudy for the majority of the day. It will become a bit breezy in the afternoon.

It will be a bit milder, but still fairly cold for mid November. High temperatures in the mid to upper 30s in Pittsfield; upper 30s in Lee, Stockbridge, Adams, North Adams and Williamstown; upper 30s to near 40 in Great Barrington and Sheffield and; low to mid 30s over the elevated terrain.

South-southwesterly winds at 5-10 mph, increasing to 10-15 mph in the afternoon.

Sunday Night and Monday

Becoming overcast Sunday night, with snow developing Monday morning. Snow will likely change to freezing rain and then rain during the afternoon. Pockets of freezing rain could persist, particularly over the elevated terrain to the north. Snow accumulations 1-3″. Possible icing over the elevated terrain. Rain and freezing rain ending during the evening.

It now appears that the surface low pressure system developing along the arctic front that was mentioned in yesterday’s forecast is developing more rapidly and closer to the coast. Therefore, it now looks like a fairly continuous period of, mostly light, snow will develop this evening around 8pm and continue til around 2am. Temperatures will, initially be above freezing in the lower elevations, so it will have trouble “sticking” at first. However, the southern track of the storm means locations in South County will get a greater liquid equivalent. The most likely snow accumulations should be 1-2″ in South County, with the higher amounts over the elevated terrain, where as much as 3″ could fall in some of the favored locations, such as Becket and Otis. In central Berkshire, 1/2″-2″ is likely, with the higher amounts over the elevated terrain. In North County, a coating to 1″ is most likely, with as much as 2″ in some spots over the elevated terrain to the east (e.g. Savoy, Florida).

The following forecast is provided by Shai Lev as part of lab work for the Introduction to Meteorology course (ATM-145) under faculty (Joe Kravitz) supervision. The forecast discussion is mine (JK) ……

A cold front at the leading edge of a deep trough in the jet stream wave pattern moved through today with a few showers accompanied by a steep drop in temperatures from about 60°F to 42°F within a 2 hour period late morning into early afternoon. As this cold trough moves over the region our temperatures will fall and remain below average through the weekend. Temperatures tonight will fall into the mid 20s with highs tomorrow generally in the low 40s. As the coldest pool of air within the trough approaches Thursday, a second “arctic” cold front at its leading edge will plow through Thursday evening with a line of snow showers and snow squalls. Expected accumulations are a dusting in most places, to as much as an inch in some heavier squalls over the elevated terrain. After this front passes, a weak surface low will develop along it. However, this low should pass off the coast well to our east and will likely not impact us.

Once this “arctic” front passes through, temperatures will turn even colder, with highs in the 30s Friday through Sunday and overnight lows near 20. On Monday, it looks like a stronger surface low will develop along the eastern margin of the trough and ride northeastward toward Berkshire County. The computer models have been struggling with consistency with this storm, however, it looks to me like we are most likely to get a mixture of precipitation, probably mostly rain as the low passes right over us, or at least very close to the coast, allowing “milder” air to move in off the ocean. However, this event is still 5 days away so I will update this with my Friday forecast.

Wednesday Night

Mostly clear and colder. Some cloudiness will build in toward daybreak.

Low temperatures in the mid 20s, some low 20s over the elevated terrain.

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

Thursday

Partly cloudy early, then increasing clouds and cooler than previous days.

High temperatures near 40 to the low 40s in Pittsfield, Lee, Stockbridge, Adams, North Adams, and Williamstown; low 40s in Great Barrington and Sheffield and; upper 30s over the elevated terrain.

Northwesterly winds at 5-10 mph in the morning, becoming light west-northwesterly in the afternoon.

Thursday Night

Mostly cloudy and seasonably cold. A band of snow showers with some embedded snow squalls is likely late in the evening. The most likely time period is between 9 pm and 1 am. Probability of precipitation 70%. Likely snowfall totals a dusting to 1″. Some clearing toward daybreak.

Low temperatures in the mid 20s.

Northwesterly winds at 5-10 mph.

Friday

A mix of clouds and sun and cold.

High temperatures in the mid 30s in Pittsfield, Lee and Stockbridge, Adams, North Adams and Williamstown; mid to upper 30s in Great Barrington and Sheffield and; low 30s over the elevated terrain. 

West-northwesterly winds at 5-10 mph.

There is no student forecast today…..

Two more mild days and then the weather in Berkshire County will turn decidedly wintry, probably for an extended period. Interestingly, this distinct change in the weather pattern all starts with a tropical system in the western Pacific Ocean. Super typhoon Nuri has undergone what is called an “extratropical transition” whereby it looses its tropical characteristics and takes on the characteristics of a midlatitude storm as it moves north out of the tropics and begins to interact with the jet stream. This interaction with the jet stream is greatly amplifying the jet stream wave pattern and this amplification is propagating eastward over North America. It is like Nuri is yanking on a rope (the jet stream) which generates a wave along the rope that travels down the rope (you can try this at home!!??). This process is called “downstream development”. The warm tropical air and cyclonic flow around Nuri, presently in the North Pacific, is generating a very strong ridge in the jet stream wave pattern over the eastern Pacific that is extending way north into the Arctic. As a result, a very deep trough is plunging south into the U.S., bringing cold arctic air with it. It appears that once this wave pattern becomes established, it is likely to take on a “standing wave” configuration where the amplified wave is maintained over a long period as the pattern itself generates storms that continually reinforce the overall jet stream pattern and prevent the wave from propagating eastward. Bottom line….it looks like temperatures will drop below average on Thursday and stay that way for the next 7-10 days as the cold trough sets up over the eastern U.S. and stays there. 

As disturbances drop into the base of the trough and generate surface low pressure systems along the eastern side of the trough we will be under the threat that they could move up the coast close enough to us to give us snow. The first of these will be on Thursday night but the disturbance and resulting low will be weak and it looks like a dusting to 1″ would be a likely accumulation if the low passes close enough to the coast. A stronger coastal storm is possible in the Sunday/Monday time period but it is too early to determine the track or strength of that low.

For the more immediate time period, as the previously mentioned trough begins to dive into the central U.S. today it has resulted in a warm ridge developing (part of the “downstream development” I mentioned) over the Northeast. As a result, temperatures surpassed 50 today and will likely surge well into the 50s on Tuesday. There may be some low clouds tomorrow as a moist southeasterly low-level flow off the ocean develops around an ocean storm well to our east. We are likely to see some, mostly light, rain showers early Wednesday as this moist flow interacts with an approaching strong cold front (signifying the eastern edge of the trough). As the front passes through Wednesday morning, temperatures will likely drop slowly in the afternoon from morning highs in the 50s. Temperatures will drop into the 20s Wednesday night and then struggle to reach 40 on Thursday. High temperatures will then not exceed the 30s from Friday through Sunday.

Monday Night

Mostly clear. Some low cloudiness developing toward morning.

Low temperatures in the low to mid 30s.

Light south-southeasterly winds.

Tuesday

A mix of sun and clouds and unseasonably mild.

High temperatures in the upper 50s in Pittsfield, Lee, Stockbridge, Adams, North Adams, and Williamstown; near 60 in Great Barrington and Sheffield and; mid 50s over the elevated terrain.

South-southeasterly winds at 5-10 mph.

Tuesday Night

Mostly cloudy and unseasonably mild. There is the chance of a shower, mostly light, toward morning. Probability of precipitation 40%. Likely rainfall totals 0.05″ or less.

Low temperatures near 50.

Light southeasterly winds.

Wednesday

Mostly cloudy and mild, with scattered showers likely in the morning, mostly light. Mostly cloudy and turning breezy and noticeably cooler during the afternoon. Probability of precipitation 60%. Likely rainfall totals 0.10″ or less. 

High temperatures will likely occur during the morning with highs in the mid 50s in Pittsfield, Lee and Stockbridge, Adams, North Adams and Williamstown; mid to upper 50s in Great Barrington and Sheffield and; low 50s over the elevated terrain. Temperatures will then drop into and through the 40s over the course of the afternoon.

Light southeasterly winds in the morning, shifting to northwesterly and increasing to 10-15 mph in the afternoon.