Tuesday 11 a.m.
Today and part of tomorrow will be mild in the I95 corridor, and mild weather is likely to return at the end of the week. That leaves a December sandwich (chilly weather slicing in) in the period from late tomorrow through Thursday night in place. For the moment, real winter has gone a-rye.
The models have offered a wide variety of possibilities recently, but so far when storms have shown up, they are preceded or accompanied by mild air. Here's another one on the long-range GFS (for Dec. 19). Snow lovers in the Great Lakes and perhaps northern New England may cheer this, but farther south, rain is likely.
One note: there do seem to be several potential precipitation producers for the dry areas in the Ohio Valley and Great Lakes during the next week or two.
The upper-air flow forecast for this evening shows the trough that helps to support rainfall ahead of the cold front.
After reaching the 80s today from NYC to Boston, it might not be that warm again through much of next week.
A noticeable push of cooler air will spread southward from Ontario and Quebec into the eastern Great Lakes and New England between tomorrow and Saturday.
A cold front from eastern Canada will slide southward along the East coast between late Friday and the end of the weekend. For the area from Philadelphia to Boston, where temperatures will reach the summery 80s each day through Friday, it will mean a noticeable change to cooler weather.
Average high temperatures in Chicago and New York City are in the mid-70s now, but for the next several days, temperatures will run 8-15 degrees above those long-term averages. Supporting this warmth is a flow aloft that originates over the Southwest:
Rain was common in the Northeast this morning, though Boston was still waiting as of 9 a.m. Their summer dry spell has continued.