Friday 9 a.m.
For a few days, the GFS model (a major U.S. model) has suggested that conditions may be favorable for snow showers downwind from the Great Lakes and into the mountains from West Virginia northeastward in about two weeks. The timing and extend of the event is changing with each new model run, but we expect that in a 12- to 16-day forecast.
In the short range, we see a low pressure area affecting the Middle and North Atlantic states. Most of the rain last night was organized into a band that extended from the ocean west-northwest through Maryland, Delaware and southern New Jersey into southern Pennsylvania. Harrisburg, Pa., had 6.35 inches of rain through 8 a.m. EDT. This means they had nearly double the average rainfall for the entire month of October in just one day! No wonder there has been major street flooding and widespread flooding of creeks and streams.
This radar composite shows the main rain area as it existed just after 8 a.m. EDT. The rain was moving toward the west-northwest, tending to dissipate as it moves through western Pennsylvania.
Here is today's forecast video for the weekend, plus a peak at what it may look like at the end of the week after next.
...after all that, the point is that zone will be north of most of the eastern half of the country. It will be very warm to hot south of the jet stream. However, weakening cold fronts can advance south of the jet stream. then return north as the next disturbance in the flow approaches.
Yesterday, the temperature hit 92 at Newark, New Jersey, and 90 in Boston. The following map shows a northerly flow affecting the Northeast today, and so it will be noticeably cooler and less humid.
This map shows lightning strokes from 8 a.m. ET yesterday through 7:54 a.m. ET today. There was quite a bit of it in Utah, Colorado, New Mexico and Arizona. For the whole map, 156,172 lightning strokes were recorded.
Looking at the west-to-east upper air flow over New England well ahead of the storm, it seems like the hurricane should stay out at sea, However, as we look through the series of maps, we see the upper-air flow congealing into a strong eastern trough that helped the storm to come right up the coast instead of heading out to sea.
On this satellite picture, we can see the basically dry weather in the Eastern states. The cold front that will ease the midweek heat in the Northeast is shown by the band of thunderstorms in the Midwest. The thunderstorms may weaken and become more scattered as the front comes into the Northeast.
A storm in the tropical Atlantic is being observed for possible strengthening. This map shows the variety of models purporting to show where the center will go. Most solutions suggest it stays well offshore, but you will notice a few outliers suggesting more threat.