Friday 10:40 a.m.
Chilly air is advancing into the Northeast this afternoon, and in many locations, tonight's chill will rival all-time records for the date. That's because the high pressure area marking the center of the chilly air mass will be right over the I95 corridor tomorrow morning, causing clear and calm conditions. Then, once the high moves to the east, a south to southwest flow of warmer air will become established. By Sunday afternoon, temperatures will be in the 60s throughout southern New England and 70 or higher farther south.
Strong thunderstorms from the middle of the country will head toward the western Great Lakes. The severe weather section at accuweather.com can be very helpful in explaining how these storms may affect you.
Tomorrow morning will be chilly in the Middle and North Atlantic states. Sam The Dog seems to like his early trip outside on cold mornings. I think it makes him appreciate the great usefulness of his fur coat.
We always look back at our previous forecasts to try to learn from episodes in which we believe we could have done better. The following satellite picture shows dry weather today in just the area that originally looked like it would have more rain.
In other words, while late summers in Phoenix have gotten wetter during the last few years, Boston has become drier. Is there anything more momentous or general that we can say about this?
This enhanced infrared satellite picture shows the cold front in the Northeast and the moisture wrapping around Odille on the southwest part of the map.
Across the Central and Northern states, thunderstorms are less common at this time of year than in late spring and summer. One area that has had more thunderstorms than usual recently is across the Desert Southwest.
Last week, I mentioned that longer range computer models were suggesting a major warmup by next weekend. More recent runs have backed off on the that idea. However, there is extreme uncertainty beyond the next 7-10 days. This can be seen by looking at the following map.
n the forecast office, we often track cold fronts with pressure maps like these. The examples are from 4AM and 10 AM today. You can see that the northern part of the front is moving more quickly than the southern end. The arrival of the front signals the start of the cooling trend that is spreading east.