Monday 10:40 a.m.
Just before 11 a.m., The National Hurricane Center officially called a storm near Jamaica T.D. 18, the 18th tropical depression of this year's tropical storm/hurricane season. It is likely to strengthen, so naming it Sandy would be the next step.
There is a significant historical precedent for a storm to form around where this is located... and then turn into a real hurricane. In 1878, a storm formed near Jamaica (near where the new storm is) then became a Category 2 hurricane and moved right up the East coast. The center passed east of Florida, then came ashore in eastern North Carolina and stayed inland until it turned almost straight east over the southern parts of Vermont and New Hampshire. There was extensive damage from the Carolinas to New England, and more than 71 people were killed. This storm came to be known as the Gale of '78.
A history of the storm was prepared by David M. Roth and High D. Cobb III of the National Weather Service in 2000. They point out that aside from Hurricane Hazel in 1954, all hurricanes with somewhat similar tracks occurred in the 19th century. Here is the storm track, as shown in the article referenced:
Now, since the newest storm has not yet had much impact, it could be asked why the new development could be important. In this video, there is one map from last evening's ECMWF (European) Model. A storm like the one depicted would be disastrous in the Middle Atlantic states, threatening death and serious injury and causing billions of dollars in damage.
Here is one of the maps that looks so threatening:
If this were to actually happen and hurricane-force winds hit places like Philadelphia and New York City, there would be a major storm surge, massive power outages, flooding rain.... and then least a foot or two of heavy wet snow near and southwest of Somerset, Pa., in the Laurel Highlands and in Garrett County, Md.
But how likely is this event? At this point, it would be irresponsible to say it is likely at all. The model showing it has changed the track with successive runs, and other models, such as the GFS, have the storm tracking well east of the area targeted on the map. Here is the GFS model forecast for the same area at the exact same time. The difference is awesome.
In the meantime, the weather seems almost anything but threatening in the Middle Atlantic states. Temperatures will be above average all week, and no rain is forecast in the I-95 corridor from Philadelphia south past Washington, D.C., all week.
A deck of clouds about a half-mile overhead spread westward from the Atlantic to much of the I95 corridor from DC to Boston early this morning. These cloud decks can be a forecaster's nightmare in the spring because ...
The map below the video is one of the GFS solutions for where the southeast storm will be early Saturday. The precipitation is predicted to be farther north than suggested by other models.
It is freezing cold in the Northeast this morning, but this map shows that much more mellow mildness has reached the Plains.
Extensive precipitation straddles both sides of the cold front that was moving through central New York and central Pennsylvania as of mid morning. This radar shows the distribution of rain and snow; some temperatures are added.
The cold front approaching the East shows up quite well in this pressure analysis. Several temperatures are plotted to give you a sense for how much the temperature changes behind the cold front. At Chicago, it went from 60 at 4 a.m. to 39 at 5:19, a 21-degree drop in little more than an hour.
Temperatures on Sunday and Monday will range from the 60s in parts of New England to near 80 in Maryland and Virginia. However, a strong cold front will then trigger and perhaps a few thunderstorms as it ushers in air that will be 30-40 degrees colder than it will be ahead of the cold front.