Tuesday, 11:10 a.m.
The weather has already turned volatile across the central and southern Plains early this morning, and it will get worse over the next 24 hours before the weather quiets down later tomorrow night and Thursday with the passage of a cold front off the East Coast. Why has the weather turned so violent so far north in late January? Hopefully this graphic will set the table:
There are really two storms in play right now. One is crossing Wisconsin and heading over central Lake Superior. It is helping draw a record warm air mass northward through Illinois into extreme southern Wisconsin at this hour. The second storm is forming in central Oklahoma, and that will be the one to do most of the damage over the next 24 to 36 hours. The dew point temperatures south and east of that developing low are over 60. For this time of the year, that is really, really high, and with so much cold air amassing north of the border, it's really little wonder why the severe weather potential is so high for the rest of today and tonight and tomorrow.
The severe weather aspect of this storm is but one facet of many to the storm. Another, of course, is the record warmth surging northward ahead of it. Chicago broke their record for the date by sunrise, and even though it won't get much warmer during the day, it underscores how balmy this air mass is. Yesterday, Topeka set their all-time January record of 77, besting the old standard by 3 degrees. Rest assured that more records will tumble today and tomorrow from the southern Plains and Mississippi Valley all the way into the East.
Still another side of this storm is the heaviest of the precipitation. Granted, the NAM model tends to suffer from some degree of convective feedback, so its quantitative precipitation forecast (QPF) tends to be somewhat bloated. Still, you can get a sense of the rainfall potential with the storm by looking at the total precipitation being spit out by the model from its 7 a.m. initialization time through 7 a.m. Thursday:
The key isn't there, so the yellow areas are at least 2 inches being produced by the model over that 48-hour window, with a pocket of red over upstate New York at over 3 inches. Many areas shaded with the lightest blue and purple colors are projected to get at least 1 inch of rain.
There will be some snow, but it won't be a lot for most areas. Most of it will be limited to parts of Kansas tonight, spreading into southern and eastern Iowa later tonight and tomorrow morning (including northwestern Missouri), then cutting across southern and eastern Wisconsin and northern portions of Illinois tomorrow as the storm darts by and the colder air rushes in before the precipitation can cut off.
Finally, there is the bitter, arctic air. It will be every bit as cold across the Dakotas and Minnesota later tonight and tomorrow through Thursday, with Minneapolis in danger of having a second sub-zero day Thursday after doing it for the first time in over four years last Monday. This cold air will drill across the Great Lakes and Ohio Valley behind the cold front later tomorrow and tomorrow night, reaching the mid-Atlantic and New England coasts later Thursday and Thursday night.
As the cold air rushes downstream, it will move over ground that will be largely devoid of snow cover. It's all gone in the Ohio Valley, and the southern edge will retreat in Michigan in the next 24 hours. Most of what snowcover is left in Pennsylvania will disappear tomorrow, while the snow will easily diminish in southern New York state, if not largely go away there, too. Even in southern New England, the snow you picked up yesterday doesn't stand a chance tomorrow into tomorrow night as temperatures and dew points at least reach the 40s, and, in many cases, into the 50s.
So, as the cold air comes east, it should begin to lose a little of its bite. That doesn't mean it won't be dramatically colder by week's end in the East, but that the departures from normal won't be nearly as big as they will be in the Dakotas and Minnesota into Wisconsin and Iowa tomorrow and Thursday into Friday. And that may be something worth noting going into next week, as there are signs the cold may not be as bad going forward after this shot comes and goes later this week into this weekend.
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.