Tuesday, 11:55 a.m.
I'm back from an extended weekend away. much of it spent in Middleville, Michigan, and the surrounding countryside. In my latest adventure into endurance sports, I participated in the National 24-hour Bike Challenge for the second year in a row. Last year I managed to rack up 226 miles before my legs and body told me enough was enough. This year, through better cross training, I managed 308.7 miles officially. I actually rode more like 321, as I got lost and off course during the first big loop of 123 miles, but they only gave me credit for hitting all of the checkpoints and that's it. Regardless, it was an epic event in my books!
The weather couldn't have been better. Cool in the morning on Saturday, then warm but not hot or humid during the afternoon hours, with temperatures peaking in the 70s. Then comfortable at night, back down in the middle to upper 50s, and there wasn't a lot of wind. That made it ideal for riding around the clock, and the record books for the event took a beating as a result. In fact, the new distance record was set (by someone in my 50-54 age bracket, of course!) at over 511 miles ridden in over 24 hours. Do the math, and you'll figure out that someone had to average over 21 miles an hour - assuming NO breaks. And if they took any breaks, that means they probably averaged over 22 mph - for 24 hours! That's insane! I guess 50 is the new 30, or something along those lines!
That cool weather is a thing of the past in most of the country. One of the more noteworthy items about the weather going forward is finally the lack of really cool, dry air from central Canada. Aside from the cool air that is now moving into the West thanks to the vigorous upper-level low over Idaho, there really won't be any cool days for a while. Here's what the afternoon 500mb chart looks like:
From that same image, you can also pick out the relatively high heights downstream over the East, with an upper-level ridge centered over the southern Appalachians. That's allowing some heat to move into the Ohio Valley, the lower Great Lakes and the mid-Atlantic states, though not without some issues. Examine the 850mb forecast for this evening:
You'll note the 15 C isotherm is very far to the north, as far north as it has been so far this year. There's a hint of 20 C air in northern Virginia and a ribbon of that kind of heat crossing the mid-Mississippi Valley. That's supportive of mid-90s F heat, and with dew point temperatures well into the 60s to over 70 degrees, it's pretty uncomfortable over a wide area.
You may also note a feature over southeastern Ontario/southwestern Quebec. That is a very weak low pressure area, with a similarly weak surface cold front. With and ahead of that feature, some powerful thunderstorms will roll out of Michigan and across upstate New York, grazing northern Pennsylvania. Some of them could wander through New England into northern New Jersey late this afternoon and tonight.
As the upper-level low tries to roll out of the Northwest into the northern Rockies toward the western Dakotas, it will pinch the upper-level ridge downstream, and a disturbance sneaking through that ridge will turn into a somewhat stronger cold front tomorrow night and Thursday. This front will march off the Northeast and mid-Atlantic coast later Thursday and Thursday night to effectively trim back the heat and humidity for a time. It's not like the air mass coming into the Northeast behind this is cool. It really won't be in the grand scheme of things, but it will at least be less humid - drier - with temperatures a few degrees below average. Here's the Friday temperature anomaly forecast:
South of this boundary, typical latter half of June heat and humidity will prevail, with temperatures at or above 90, but not by a lot, with mainly afternoon and evening thunderstorms. It won't be excessive, with records being set, or temperatures approaching 100, but it will certainly feel mighty uncomfortable, with no organized thunderstorm activity from Texas to South Carolina, if not North Carolina.
And after a cool period through midweek in the West, it will warm nicely in the coming days, with temperatures back up to normal or so by the weekend.
Two systems will delay the onset of warm weather in the Ohio Valley and the East over the next week or so, but then it should get warm all across the country heading into the Memorial Day weekend.
A turn to much colder air over the Northeast and mid-Atlantic states will set the stage for a rain and snow storm later this weekend before it turns much warmer later next week.
It's warm now, but will turn much colder this weekend, with a storm threat later Saturday into Sunday. Warmth will return by the second half of next week.
Though it is cold now east of the Mississippi, with a couple of opportunities for snow into the weekend, a blast of warmth is due for much of the country east of the Rockies next week.
Warm air will once again surge eastward from the Plains to the East Coast this weekend and early next week. A strong storm next Tuesday and Wednesday will then be followed by colder air later next week.
A storm in Southeast Texas will generate severe thunderstorms this afternoon and tonight, and some wet snow on its western flank as it heads into the Ohio Valley tomorrow.