Monday 10 a.m.
A loosely organized storm in the Plains will move east and transform into well-organized, gale-producing storm off the East coast. That's the easy part. The challenge is assessing how far north the heavy snow extend. The reason that is so important is that, within a distance of about 150 miles, accumulations can range from a covering to well over a foot.
With many situations, we see a track curving to the northeast as the main storm strengthens offshore. This happens because the upper-air trough helping to support and steer the storm gets deeper, and the flow ahead of it becomes more southerly. Last night's GFS predicted exactly that, and if taken literally, suggests 18 inches of snow for Boston Wednesday night and Thursday after dumping more than 6 inches on New York City.
However, there is a blocking pattern in place over northern New England and eastern Canada. If the block holds, the storm will detour out to sea instead of turning up the coast. That's exactly what the European model predicted last night and why it projects less than inch of snow for both New York City and Boston. Meanwhile, both models predict at least 6 inches of snow for Chicago. Here's my morning video.
This map is a working draft of our snow accumulation predictions. Please check our latest videos and stories to learn more about this developing situation.
It is not going to snow any time soon, but in any type of weather the flag is a symbol of freedom. This holiday weekend we celebrate the contributions of those who were there to defend the freedoms we enjoy in these times.
Once again, the rain will miss much of central and northern New England. The region has been in a dry spell, as evidenced by its appearance on this U.S Drought Monitor map.
A cold front crossed the Northeast yesterday. Looking at these maps, which show morning temperatures yesterday versus readings around the same time today, we can see that the biggest drop in temperatures occurred around the lower Great Lakes.
Much of eastern New England has been in a dry spell ever since the last snow melted. More dry weather is on the way from tomorrow through the end of the week. This radar image taken at mid-morning Tuesday is peppered with showers.
Cooling will also occur from Wisconsin into western Michigan as a cold front moves eastward. This map shows the arrangement of fronts and the area of relatively warm air between the two cool air masses:
The worst storms later in the weekend will precede the cold front that brings cooler air back into the Northeast next week. This map shows the threat as outlined by the NWS Storm Prediction Center: