Tuesday 9 a.m.
As winds aloft become southwesterly, mild, moist air from the Gulf of Mexico will spread all the way up the East coast. This weekend, temperatures can climb well into the 60s in Washington, D.C., and past 50 degrees in Boston. It will also be milder than average across most of the Great Lakes region through the start of the weekend.
After the mild spell, both the GFS (U.S. model) and ECMWF (European Model) show cold air advancing east and south. There are differences between the models as to how quickly and how far the first surge of cold air will advance. However, both suggest that once cold air takes over, it may be persistent. For example, the GFS ensemble mean (the model is run multiple times, then averaged) predicts that once it goes below freezing next week, it stays below freezing day and night for at least a week (the model runs out to 16 days). The video has more.
Regardless of when or how cold it gets, our dog Sam looks like he is ready. Very soon, Sam will complete his twelfth year as part of our family. As an American Eskimo dog, I suspect he naturally likes rolling around in the snow. He really liked the deep snow we had in the yard last week, so I patiently watched him play (even though I was getting cold). If you've had a beloved pet for a long time, I suspect you have shared the feelings I had watching Sam in the snow... that one of these days....
It was nice seeing Sam the Dog looking contented like he did a few years ago on a summer day...
Here is the severe weather outlook for today from the NWS Storm Prediction Center. Note at the bottom the population in each alert area is listed. Keep in mind that in any given severe weather situation, the number of individuals directly affected is far less than the number of people potentially threatened.
South of the cold front, the air has become rather polluted. Sunshine operating on the hazy air will help to generate ozone. This map shows expected air quality for today.
The most intense and concentrated lightning zone yesterday was not associated with the eastern low pressure area but rather with a low pressure and a virtually stationary front in the Plains.
In response to cold air aloft, daytime heating at ground level and available moisture, showers and thunderstorms will develop today from Pennsylvania and southern New Jersey on south through Virginia.
Rain will be followed by sunny days in the Ohio Valley and parts of the Appalachians, but it may take two to three days for clouds and the threat of showers to inch east of the Northeast and Middle Atlantic coast early next week.