Wednesday 10 a.m.
Temperatures a mile overhead in the Northeast today would support afternoon ground-level temperatures well up in the 80s today... if this were July. In July, the sun climbs high in the sky. Mornings warm quickly; soon it is very warm or hot. Not so fast in October, though. The longer nights allow more time for the temperature to drop to the saturation point, and soon fog forms.
The fog prevents much solar energy from the reaching the ground to cause warming. If there are higher clouds around like there are at many places today. the warming process is delayed further... and before we know it the sun is sinking back toward the horizon. The changing amounts of clouds and fog can wreak havoc on temperature forecasts. Despite this, we can say confidently that temperatures in Middle and North Atlantic states will run higher than the long-term averages for this time of year.
Fog may redevelop late tonight and longer tomorrow morning. On Friday, however, slightly drier air will advance from the west and southwest... and with the breeze picking up, it could turn out to be the warmest day of the week. A cold front will arrive and be followed by noticeably cooler air for the weekend. The cold front is associated with a low pressure area that will cause heavy snow across parts of the far North Central states and adjacent Canada. This video shows the expected progression of events:
Dense fog has often proven to be very challenging for painters and photographers. You can see why with this image from a webcam overlooking the area between the Statue of Liberty and the buildings of Manhattan.
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.