The following forecast is provided by Joseph Botto, in conjunction with the instructor, as part of lab work for the Introduction to Meteorology course:
Summary: Surface low pressure, originally associated with Sandy, has finally moved far enough away (through the Canadian Maritime and into the North Atlantic Ocean) to allow surface high pressure to move in from the west. This will result in clear skies tonight and tomorrow before the next storm moves up the East Coast on Wednesday. As surface high pressure builds over Berkshire County tonight and becomes centered directly over us tomorrow, skies will become clear due to the large scale descent in the atmosphere associated with the surface high. Winds will also become calm tonight and remain light tomorrow as the pressure gradient becomes weak near the center of the high. With clear skies, calm winds and dry (dewpoint of 16 deg. F) air in place we will have an ideal radiational cooling night tonight and temperatures should drop into the teens countywide. Light winds and a low sun angle tomorrow will prevent us from breaking the radiation inversion (colder near the ground and warmer aloft) that develops by morning. Therefore, despite plentiful sunshine, it will remain unseasonably cold tomorrow with temperatures remaining in the 30s in most locations. It may creep into the low 40s in South County by afternoon. Although Tuesday night will again have ideal radiational cooling conditions early, clouds will begin to increase towards morning and a light easterly breeze will also develop. Therefore, temperatures will not be quite as cold as tonight but will still drop well into the 20s.
A weak surface low pressure system presently over the lower Mississippi Valley will gradually rotate around the base of the trough (southern dip) in the jet stream, along with the upper-level disturbance that is generating the surface low, into a location more favorable for development on the eastern side of the trough and out over the Gulf Stream by Wednesday. As a result, the surface low will deepen rapidly from a central pressure of 1008 mb on Tuesday evening to 990 mb by Wednesday evening when it will be located off the New Jersey coast. Conditions do not appear to be as favorable for development as they appeared a few days ago and, as such, it does not appear that this Nor’easter will be nearly as strong as looked like it might get earlier. The pressure gradient will be fairly strong and so the winds will be strong, but not nearly as strong as with Sandy. To put things in perspective, the record low central pressure with Sandy was 940 mb (compared with 990 mb for this storm). The big forecasting question is what type of precipitation we will get in Berkshire County from late Wednesday afternoon into Thursday morning AND how much we will get. A storm track to our east, with the surface low moving just to the east of Cape Cod and into the Gulf of Maine that this storm will follow is the classic track for a snowstorm, with us in the colder air to the northwest of the low. That would definitely be the case if this were winter. However, ocean water temperatures are still in the 50s and as the warmer air over the ocean circulates around the low and rides up over the cold, low-level air over Berkshire County, it could create a warm enough layer aloft to cause the snow to change to sleet. That is how things looked earlier. However, the European model (ECMWF) run from this morning has the storm a little farther to the east with our precipitation remaining all snow. This model has been the best in recent years. In addition, the most recent (1 pm) GFS model run shows a similar scenario. This would result in us getting all snow but getting less. Given this trend, all snow appears to be most likely but with a relatively light accumulation (e.g. 2-4″). However, with this scenario, we would be right on the western edge of the precipitation shield and so the forecast has a large degree of uncertainty with still 48 hours before the storm arrives. Even a slight shift in the projected storm track could change the forecast dramatically. More to come tomorrow…..
Monday Night
Clear, calm and cold.
Ideal radiational cooling conditions will permit temperatures to drop into the teens countywide. Low temperatures will be in the upper teens in most locations with mid teens in the usually colder valleys.
Light northwest winds becoming calm after midnight.
Tuesday
Mostly sunny and cold.
Temperature will remain in the 30s in most locations despite plentiful sunshine. However, it should feel warmer than the actual temperature with light winds and sunshine. High temperatures in the upper 30s in Pittsfield, near 40 in Williamstown, Adams and North Adams, low 40s in South County and mid 30s in the elevated terrain and hilltowns.
Winds light and variable.
Tuesday Night
Clear early with some increase in clouds after midnight. The clouds will mostly be high clouds but some mid-level clouds could arrive before morning.
It will be cold, but not as cold as Monday night due to some cloud cover and a bit of a breeze after midnight. Low temperatures in the low to mid 20s.
Calm in the evening. Easterly winds at 5-10 mph developing after midnight.
Wednesday
Partly cloudy in the early morning with increasing clouds, lowering and thickening, throughout the day. Snow likely developing late afternoon to early evening. Any accumulation should be light (an inch or two at most by evening).
It will remain fairly cold, with high temperatures in the mid 30s in Pittsfield, mid to upper 30s in Adams, North Adams and Williamstown, upper 30s in South County and low 30s over elevated terrain and the hilltowns.
Northeast winds (NAWEASTAH) increasing to 10-20 mph by afternoon.