Wednesday, 11:30 a.m.
On Monday's post, I mentioned three main worries about the forecast in general going forward. One dealt with heavy, excessive rain in two areas, one stretching from the Midwest into the Ohio Valley through the heart of the week and the other east of the Appalachians from Friday into next week. Of those two, the one is ongoing, and we've seen several inches of rain and flash flooding overnight and this morning in northern Illinois, southernmost Wisconsin, and now into northern Indiana. We're not out of the woods yet with the heavy rainfall potential as the upper-level trough now rotating across the Midwest turns the corner and heads into the Great Lakes and Ohio Valley tonight and tomorrow. Look at the 12z 26 June NAM total precipitation forecast from this morning through tomorrow evening:
If you expand this out through Saturday, you'll begin to see how this feature stalls, and the rains can pile up over parts of the central and northern Appalachians and adjacent areas:
And we haven't really even talked about how the pattern amplification now underway will help to strengthen a western upper-level ridge, as well as a similar one off the East Coast, with a deepening upper-level trough stuck in between, and how that will lead to a persistent corridor of moisture and the potential for excessive rains over areas that are already wet from so much rain already this month! That's a subject for another day as it draws closer.
On that Monday post, I also talked about two other areas of concern, both dealing with the worry over forest fires. One was the central and southern Rockies, the other Alaska. Well, here's the morning update on that. From the USDA Forest Service, the latest scoop on their map of active wild fires in the general area:
Four new, large fires broke out in Alaska yesterday, bringing the total there to nine in additional to many smaller blazes:
In Alaska, there may be some relief on the way next week as the upper-level ridging finally breaks down and pulls moisture into the state from the Pacific and hopefully leads to sufficient showers that will help bring those blazes under control.
There may also be some token relief over the weekend in Colorado as a few thunderstorms appear likely to bubble up along the Divide. My worry is that will mean little real rain for the areas that need it, and yet they could spark more fires or cause gusty winds in the vicinity of those already in existence. The upper-level ridge will also get pinched westward a bit early next week, so there may be some nominal rain chances farther west in the state and across New Mexico. That said, the danger of new or expanded blazes in the region will likely go up, not down, between now and the weekend. The whole area is basically a tinder box that is bracing for a match to ignite things.
The polar vortex will roll south-southeastward over the next three days, descending upon the Great Lakes and Northeast this weekend with the coldest air mass of the winter season.
A wave of low pressure will clip the mid-Atlantic coast late tomorrow and tomorrow night, possibly resulting in some snow. A stronger storm could bring snow to parts of the East next week.
A deepening storm coming out of the Rockies and head for the Great Lakes will dump heavy snow from Colorado to Wisconsin and Minnesota, while springlike warmth will fuel severe thunderstorms from the Ohio Valley to the Gulf Coast.
Despite the historical snowfall from the Blizzard of 2016, a warm surge later this weekend and early next week will wipe out most of the snow that fell during the storm.
A major nor'easter will bring heavy, wind-blown snow through the mid-Atlantic region later Friday through Saturday, sparing much of New England of its fury.
A deepening storm heading for the East Coast Friday night may paralyze parts of the mid-Atlantic with heavy snow and strong winds through Saturday.