
Overall, we will see increasing temperatures through the next week along with an increasing dew points. Despite sunny skies the last few days, anomalously cold air aloft has limited high temperatures over the region. Clear skies have also allowed for notable radiational cooling. This will be no different tonight and tomorrow night, as temperatures dip into the 40's.
Cyclonic flow and cold pool aloft will maintain some instability over New England tomorrow, so similar to today, we will likely see a diurnal increase in clouds. However, moisture is very limited, so precipitation is not expected.
Wednesday, cyclonic flow departs / negative vorticity advection. Surface high pressure will move into place. The column will be very dry so should maintain sunny skies through the day. Highs making it to the upper 70's.
By Wednesday night, winds back to the southwest ahead of the next piece of energy dropping into the Great Lakes. This will transport warmth and moisture northward overnight and into Thursday morning. Expect clouds and showers through the morning. The cloudiness should limit high temperatures despite 850mb temps reaching 15C. Surface based instability may lack as a result, however cold air aloft should help elevated convection to develop and a chance for thunderstorms has been inserted into the forecast accordingly.
Friday through Saturday, shortwave remains to our west, but there is more confusion in the model guidance as to a focus for precipitation over the region. We will have the moisture available, but organized precipitation remains questionable. At this point kept Friday dry but cloudy and showers possible Saturday. Sunday, the trough lifts northeast which could drag a final boundary across the region triggering a few showers. In addition, model guidance has been developing a wave along the boundary and riding it northeast, which could mean an even wetter forecast mainly for eastern New England.
Monday, should see partial clearing with dry conditions. Pattern-wise, model guidance continues to push toward more zonal flow by next week. Although maintaining above normal high latitude heights, below normal heights begin building over polar latitudes / finally a neutralization of the Artic Oscillation. At this point I'm expecting a westward shift in the trough axis toward the Ohio Valley, and ridging building slowly over the west Atlantic.
|posted by Sam Lillo @ 7/13/2009 08:33:00 PM