Monday, 11:35 a.m.
My time is short, but the nuts and bolts of this week's forecast are NOT about Debby, the weakened tropical storm that is rolling around aimlessly at the moment off the coast of the Florida Panhandle. It is beginning to move slowly northeastward and should drift in that general east or northeast direction over the next couple of days, continuing to lash the Florida Peninsula with heavy rain and gusty winds.
The presence of Debby, however, is helping have an impact on the current weather and the weather to come, specifically as it relates to heat. Look at the upper-level flow pattern today:
The large-scale features are very impressive! The deepening trough coming into the East, though, is going to be blunted a bit by all of the heat being thrown off Debby to the north. That heat is manifesting itself in record or near-record heat across the South and into the eastern Rockies. Look at the highs from Sunday:
The incredible heat will easily expand eastward this week, faster than I had thought last week. And what heat it is going to be. Look at the latest NAM projected 850mb temperatures for Thursday evening:
The air mass that promoted the mid- to upper 90s kind of heat in the mid-Atlantic into portions of New England last Wednesday through Friday had 850mb temperatures of +21C or maybe +22C. This has +15 and higher for places like Chicago, St. Louis, and Columbus, and it is expanding rapidly eastward. That may well mean temperatures over 100 over a LARGE area of the country by Thursday. The NAM 2-meter temperature forecast concurs:
This could just obliterate records this week, as the heat will return to the East by Friday and linger into Saturday before ANY kind of cooling can take place, and even then, it may be tough to get it back to normal for a while. In other words, you might want to start preparing now for a run of just unrelenting heat and probably some oppressive humidity in the coming days, if it hasn't already started for you!
The record warmth of recent days will be replaced by a much colder air mass following a cold front moving from the Ohio Valley to the East. Rain will change to snow in the higher ground of upstate New York and northern New England.
Nicole crossed Bermuda Thursday morning as a major hurricane. Two storms will blast the Northwest with high winds and heavy rains in the next 72 hours, forcing warmer air out into the nation's midsection.
Matthew is a dangerous hurricane bearing down on the east coast of Florida. While it ravages Florida and parts of the Southeast into the weekend, it will spare the Northeast of its fury.
Major Hurricane Matthew is now a significant threat to the entire Eastern Seaboard Thursday through the weekend with with potentially destructive winds and excessive rains.
Heavy rain will soak drought-stricken areas of the mid-Atlantic over the next couple of days. Focus will then shift to Matthew and its potential to impact the Eastern Seaboard with more heavy rain later next week.
Summer has ended astronomically, but from a meteorological standpoint, there's plenty more warm weather heading into October from the Plains to the East.