Mar 26, 2012; 10:14 AM ET
Monday, 11:40 A.M.
In keeping with the somber mood within AccuWeather.com today, the weather seems to be taking a little time off. It's not that we won't have any weather, but that it will not be as active as it has been, nor as active as it can be in late March given all of the variation across the country.
The biggest change is taking place in the Northeast and mid-Atlantic today, where a strong and fast-moving cold front is sweeping away the last of the balmy weather that had been commonplace in the past couple of weeks. Over the weekend there was enough cloudiness and moisture combined with an east-to-northeast wind flow to cool off much of New England and the mid-Atlantic states, but now a much colder air mass is drilling into these areas behind the front.
Unfortunately, there will be a steep price paid in many areas for that incredible run of early season warmth. Temperatures will drop well below freezing tonight, and probably below 28 degrees for a long enough period overnight to cause some problems to the flowers and trees and fruit trees that have gone into some degree of bloom weeks earlier than would normally be the case. I'm not sure I want to see the results of this damage in the coming days and weeks.
The area of frost potential will be much more confined tomorrow night to areas from around the Hudson Valley into New England. Not only will high pressure be fading fast to the east, but high clouds will be rapidly advancing in from the west, and they should help to keep frost from forming any place father west tomorrow night. By then, though, much of the damage will have taken place from the cold shot tonight.
Not all of the record heat is over, though. A few more record highs fell on Sunday out over the western Plains and eastern Rockies, and a few more will be erased this afternoon. The danger over the Front Range of the Rockies is that of wild fires this afternoon and evening, as strong winds gusting over 50 mph at times will lower the humidity to around 10 percent this afternoon. Red flag warnings have been hoisted over much of eastern Colorado, and with an overall lack of moisture during the late winter and spring, the threat is very high for wildfires to not only get started, but to grow rapidly. Fortunately, the winds will abate tonight. However, there is little moisture forecast for these areas into the weekend, and it will remain warm. Another round of strong winds may be due in late Saturday and Sunday, raising the risk of wild fires even more at that time.
The storm that delivered rain to Southern California yesterday and brought an early end to the NASCAR race is the same feature that is generating all the wind in the eastern Rockies today. In the wake of it, the Southwest will be dry this afternoon into tomorrow, but another upstream feature will send rain back to the Northwest coast and into northern California later tomorrow and tomorrow night into Wednesday.
A piece of that system will move across the northern Rockies Thursday, and then out onto the northern Plains, but will not have a lot of moisture to work with initially. Still, southerly winds ahead of it will transport enough Gulf moisture northward to bring the dew points way up, generate a fair amount of clouds, and, eventually, scattered showers and thunderstorms. The combination of all of the above will keep overnight lows up near or even above the normal highs for late March in the central and northern Plains once again, leading to some phenomenal temperature departures.
With all of that warmth quickly returning to the Plains this week, some of it will try to come eastward. The feature that cross the northern Plains this afternoon and tonight will help draw that warmth into the western Ohio Valley and parts of the Midwest tomorrow, then to the mid-Atlantic on Wednesday. However, after that, the upper level trough re-establishes itself later this week along and off the Northeast coast, which means this round of warming will be quite short, and nowhere near as strong as last week's run of warmth.
Then, when you look at what is happening downstream, you get the impression any subsequent system coming across the Plains late this week will also be forced to turn southeastward in time:
That high over low block that may only temporarily set up should be enough to force the late-week feature southeastward over the weekend, preventing warm air from ever reaching the Lakes and Northeast to end the month.
No comments:
Post a Comment