Tuesday 9 a.m.
Cold air is blasting into the Northeast this morning. Between midnight and 8 a.m., Philadelphia had a drop from 51 to 35, Boston 49 to 35 and New York City 51 to 35. Showers changed to snow, but no accumulation has occurred on city streets and it will dry out this afternoon.
The high pressure area marking the center of the cold air mass will be over South Carolina by Thursday morning, and the southwesterly flow behind it will run from Texas to New England. At first, it will be sunny during the warmup. However, as much from the Gulf states advances, clouds will pop up, and perhaps showers will reach the I95 corridor Sunday and Monday. No new cold fronts will reach the Northeast in the meantime.
This pressure map shows tight packing of lines where cold air is temporarily dammed up against the Appalachians. Across New York state and New England, the chilly air was flowing south more readily.
A cold front that will cross the Northeast and Middle Atlantic states this afternoon and evening will trigger showers and, in some places, a thunderstorm. Once the front is offshore, a high pressure area from the Midwest will take over for the weekend.
This map shows the high pressure area that is promoting cool, dry weather in the Northeast today. The low pressure area on the left side of the map is associated with a cold front that will send showers eastward tomorrow.
With fine weather likely on most of the days ahead through early next week, leaf viewing will be a cool experience for many, especially in areas highlighted on this map showing the typical progression of peak fall colors:
This map is a forecast of the upper air flow early on Saturday, Oct. 16. It shows a mild to warm pattern for the Great Lakes and Northeast. The second map is for two weeks from today. Northern snow showers, anyone?
...with almost 16 inches of rain in Myrtle Beach, South Carolina, and more than 20 inches around Charleston. You don't find amounts like that anywhere in the historic record for this area. This picture shows the radar-estimated rainfall over South Carolina between Friday afternoon and mid morning today:
This map shows where Hurricane Joaquin was just before 8 a.m. ET. You can also see the stripe of clouds centered just of the Middle and North Atlantic coasts.