A storm system passing to our west will be remembered mostly as a rain storm. But first, there will be a brief period of winter weather. First, for tonight, temperatures may be a bit complicated, as we'll have an opportunity to radiate for the first half of the night, then clouds will increase ahead of the storm system. In general, though, since most of the clouds will be of the high variety, think radiational cooling will be pretty good. Low temperatures should range from the low 20s in the normally-colder spots, to around 30 along the south coast.
For tomorrow, overrunning (warm air moving on top of a cold air mass) will bring precipitation into the area. Thermal profiles, especially aloft, are cold enough to support snow everywhere. Right now, the timing looks to be from around noon in the southwest to mid afternoon in the northeast. Most places will not see a lot of accumulation of snow. Please refer to the snowmap at the end of the discussion. In general, a statewide average for snowfall accumulations will be around an inch. A few areas, such as in the Oxford-Waterbury hills may see a localized two inch amount. Some locations east of Interstate 91 and South of Interstate 91 may not see any snow at all. But in general, around an inch looks to be the best bet. By rush hour, snow will be in the process of turning to rain along the south coast, and by midnight the changeover should be complete in the north.
Then is the next problem. Along the south coast, temperatures will probably be in the 33-35 degrees at their lowest point even when the snow is falling, and then only rise from there. Therefore, most accumulations should be restricted to colder surfaces, and there is no concern about freezing rain. However, further north, temperatures will probably fall into the 28-30 degree range, allowing snow to accumulate everywhere and also creating a small window of concern for freezing rain. In general, the time frame in question is between 10 PM and 6 AM for freezing rain and freezing drizzle in these areas. Fortunately, this is when traffic is the lowest. However, with it being dark, it would be that much more dangerous for anyone driving. Up to a tenth of an inch of ice could accumulate in those areas.
The only caveat would be if evaporational cooling allows temperatures to fall more than progged. We'll need to keep an eye on dew points tomorrow to see how much the atmosphere may potentially cool. This won't be resolved until the time of the event, unfortunately.
Phase Two of this storm will occur Wednesday, as the actual low pressure system tracking to our west spreads its precipitation into the area. This precipitation should be all rain everywhere, as temperatures rise rapidly. There will probably be a break between the two rounds of precipitation, during the late morning hours on Wednesday in the Southwest and midday hours in the Northeast. However, timing and placing these breaks is often futile until the event begins. There will also be lingering low level moisture during this time frame, so there could very well be spotty drizzle during this break. Phase Two will then begin in earnest, with rain becoming steadier and heavier as the event goes on. During Wednesday night (the timing is a bit uncertain still, so we'll just say during the night), there will also be numerous thunderstorms as the cold front nears. Some of these thunderstorms could coalesce into a squall line late Wednesday night and produce wind gusts in excess of 50 MPH!
As far as non-thunderstorm winds go during the event, it will be breezy tomorrow, but not overly windy. Winds will then diminish for a time on Wednesday (probably coincident with the break in the precipitation), then when the low center and cold front get closer, winds will increase rapidly with gusts up to 40 MPH. As mentioned above, winds could gust in excess of 50 MPH with any stronger thunderstorms! In addition, very warm air will move into the state for a few hours Wednesday night! It is very probable that aside from a few sheltered valleys, most of the state exceeds 60 degrees for an hour or two!
Rain ends during the morning hours on Thursday, as the cold front passes. The air immediately behind this cold front is not overly cold, so we still expect high temperatures to crack 50. The combination of a second, stronger cold front's approach, and an upper level low will trigger more showers during the day Thursday. Temperatures will begin to rapidly fall Thursday night and precipitation should begin to change to sleet and snow, but no accumulations are expected.
On Friday, much colder air will move in behind the front. Once again, some snow showers are possible, especially up over the Litchfield Hills, where a dusting could accumulate. Highs on Friday will generally be in the 40-45 degree range.
The weekend will generally be fair and tranquil, with temperatures pretty close to normal. Saturday morning could briefly be quite cold, especially in the north, but daytime highs will likely be near 40 Saturday and in the low 40s Sunday.
Then on Monday, as a cold front approaches, temperatures may get briefly much warmer, followed by a shot of rain with the frontal passage. Highs on Monday should approach 50 degrees, so any precipitation should be rain.
Looking further into the long range, blocking may develop in two key areas: one over the Western half of North America, and the other over Greenland, which could force us into a cold and potentially snowy pattern in the first ten days of March, so winter may not be done just yet!
Now, here are a few maps to illustrate the upcoming storm system graphically!
First, this is our snow and ice accumulation map. As you can see, there won't be big accumulations anywhere, but icing is always dangerous. Areas outlined in icing should use extra caution.
For tomorrow, overrunning (warm air moving on top of a cold air mass) will bring precipitation into the area. Thermal profiles, especially aloft, are cold enough to support snow everywhere. Right now, the timing looks to be from around noon in the southwest to mid afternoon in the northeast. Most places will not see a lot of accumulation of snow. Please refer to the snowmap at the end of the discussion. In general, a statewide average for snowfall accumulations will be around an inch. A few areas, such as in the Oxford-Waterbury hills may see a localized two inch amount. Some locations east of Interstate 91 and South of Interstate 91 may not see any snow at all. But in general, around an inch looks to be the best bet. By rush hour, snow will be in the process of turning to rain along the south coast, and by midnight the changeover should be complete in the north.
Then is the next problem. Along the south coast, temperatures will probably be in the 33-35 degrees at their lowest point even when the snow is falling, and then only rise from there. Therefore, most accumulations should be restricted to colder surfaces, and there is no concern about freezing rain. However, further north, temperatures will probably fall into the 28-30 degree range, allowing snow to accumulate everywhere and also creating a small window of concern for freezing rain. In general, the time frame in question is between 10 PM and 6 AM for freezing rain and freezing drizzle in these areas. Fortunately, this is when traffic is the lowest. However, with it being dark, it would be that much more dangerous for anyone driving. Up to a tenth of an inch of ice could accumulate in those areas.
The only caveat would be if evaporational cooling allows temperatures to fall more than progged. We'll need to keep an eye on dew points tomorrow to see how much the atmosphere may potentially cool. This won't be resolved until the time of the event, unfortunately.
Phase Two of this storm will occur Wednesday, as the actual low pressure system tracking to our west spreads its precipitation into the area. This precipitation should be all rain everywhere, as temperatures rise rapidly. There will probably be a break between the two rounds of precipitation, during the late morning hours on Wednesday in the Southwest and midday hours in the Northeast. However, timing and placing these breaks is often futile until the event begins. There will also be lingering low level moisture during this time frame, so there could very well be spotty drizzle during this break. Phase Two will then begin in earnest, with rain becoming steadier and heavier as the event goes on. During Wednesday night (the timing is a bit uncertain still, so we'll just say during the night), there will also be numerous thunderstorms as the cold front nears. Some of these thunderstorms could coalesce into a squall line late Wednesday night and produce wind gusts in excess of 50 MPH!
As far as non-thunderstorm winds go during the event, it will be breezy tomorrow, but not overly windy. Winds will then diminish for a time on Wednesday (probably coincident with the break in the precipitation), then when the low center and cold front get closer, winds will increase rapidly with gusts up to 40 MPH. As mentioned above, winds could gust in excess of 50 MPH with any stronger thunderstorms! In addition, very warm air will move into the state for a few hours Wednesday night! It is very probable that aside from a few sheltered valleys, most of the state exceeds 60 degrees for an hour or two!
Rain ends during the morning hours on Thursday, as the cold front passes. The air immediately behind this cold front is not overly cold, so we still expect high temperatures to crack 50. The combination of a second, stronger cold front's approach, and an upper level low will trigger more showers during the day Thursday. Temperatures will begin to rapidly fall Thursday night and precipitation should begin to change to sleet and snow, but no accumulations are expected.
On Friday, much colder air will move in behind the front. Once again, some snow showers are possible, especially up over the Litchfield Hills, where a dusting could accumulate. Highs on Friday will generally be in the 40-45 degree range.
The weekend will generally be fair and tranquil, with temperatures pretty close to normal. Saturday morning could briefly be quite cold, especially in the north, but daytime highs will likely be near 40 Saturday and in the low 40s Sunday.
Then on Monday, as a cold front approaches, temperatures may get briefly much warmer, followed by a shot of rain with the frontal passage. Highs on Monday should approach 50 degrees, so any precipitation should be rain.
Looking further into the long range, blocking may develop in two key areas: one over the Western half of North America, and the other over Greenland, which could force us into a cold and potentially snowy pattern in the first ten days of March, so winter may not be done just yet!
Now, here are a few maps to illustrate the upcoming storm system graphically!
First, this is our snow and ice accumulation map. As you can see, there won't be big accumulations anywhere, but icing is always dangerous. Areas outlined in icing should use extra caution.
The next map is projected winds just above the surface, valid around midnight Wednesday night. You can see winds are very strong just above the surface, and any stronger thunderstorms should bring down these strong winds!
Finally, the last map is total precipitation through Thursday afternoon. As you can see, this event will be a significant precipitation maker- with over 2 inches for most of the state, except a little less in the north and west.
That's all for now!
-GP!
-GP!
