Hoosier

Rochelle got down to 41.

00z HRRR/RAP/NAM all drop dews under 40 tomorrow in/around Chicago.

Quite a temperature gradient progged across that front next week. South of it should manage 90+ in some areas, while it will be a far different story on the other side.

I would call 0.96" in the past 30 days terrible. Especially since the temps haven't been cool.

Pretty impressive what has happened there. It was 84/60 an hour ago.

RH is down to ~20% at ORD. 85/39

Just your routine 95 to 35. Not really familiar with Denver climo, but that amount of snow strikes me as unusually early even for them.

Looks like the high likely was 88. May have been able to buy another degree or so if the cloud deck hadn't come in prior to the frontal passage.

Based on precip departure maps, parts of Ashtabula county have been running significantly below average.

There's a time series feature on the drought monitor site where you can look down to cwa level or even county/city level. No idea how long it's been there but I just discovered it. Anyway, you have to go back to 2012 to find the last time that so much of Chicago metro was in D1 or higher. It briefly snuck into far southern parts of the metro in fall 2013. Goes to show how wet it has been overall during the past several years.

86 now This should be a close one. Warming probably cuts off after about 2 more hours, so the race is on to squeak out 4 more degrees.

GFS looks to be taking some steps away from its previous solutions. Maybe we will sort of end up in a compromise between Wednesday's 12z Euro and Wednesday's 12z GFS, but lots of runs to go.

Already 84 at ORD. Normally that would make 90 very likely, but we are dealing with a frontal passage later to complicate things.

The data cutoff is Tuesday at 8 am eastern, and while some areas received decent rain on Tuesday, I'm not sure that single rain would have had any significant impact on this map.

88 at ORD and Midway. A bit of an overperformance. Dews have actually dropped into the 40s at both sites.

LOT's take is that there is not much room for a compromise solution. The main player in building the central CONUS trough early next week is stalled near the Aleutians, so the forecast will be highly dependent on when (or how much of) that energy is displaced into mainland North America. Additionally, guidance shows a significant divergence in solutions by mid-week, producing about as large of a disparity in the forecast as one could see a week out. Raw deterministic max temps by mid-week vary by as much as 40 degrees between the GFS (50s) and ECMWF (around 90), owing entirely to whether the central CONUS trough becomes cut off (ECMWF) vs. ejecting northeast through the Great Lakes (GFS). The potential for a highly baroclinic boundary to stall across the Upper Great Lakes/Mississippi River Valley ahead of the Great Plains trough will lead to a rather active period with heavy rain and periods of potentially strong to severe convection somewhere in the region Monday into Wednesday. The CWA is precariously close to this boundary in guidance, so prepare for the potential of significant changes in the forecast next week. Statistically speaking, the forecast spectrum is quite binary and produces more of a double bell curve...either unseasonably warm and dry or unseasonably cold and wet with, low probabilities of something in between. Kluber

Does Euro still have a bias with cutoffs or is that a thing of the past?

Hopefully we get a favorable wind direction.

Some issues/questions for Sunday, but wind fields aren't one of them. That part looks decent.

Ever seen 0C 850 mb progged into southern Iowa/northern Missouri prior to the middle of September? Not some 300 hour thing either. While I'd have to think it is overdone, could we see 850's in the low-mid single digits?

I wonder if Vegas will outsnow Kitchener this winter.

Just out of curiosity, I took a look at Rockford's stats for the summer and they had their 6th warmest summer on record. So yes, there was some local "enhancement" around Chicago, but it was one of the warmer summers across the area. As far as Chicago, here is more from LOT: Public Information Statement National Weather Service Chicago IL 401 PM CDT Tue Sep 1 2020 /501 PM EDT Tue Sep 1 2020/ ...A Look Back at the Climate for Meteorological Summer (June, July, August) 2020 for Chicago and Rockford... At Chicago, the average high temperature for the summer season was 86.2 degrees, which is 4.3 degrees above the 1981 to 2010 average. The average low temperature was 67.1 degrees, which is 5.4 degrees above normal. The mean temperature for the season was 76.7 degrees, which is 4.9 degrees above normal.

Somebody measured a 25 mb pressure drop in 7 minutes in the derecho. You don't even get that drop rate in the eyewall of most (if not all) hurricanes.

The system progged for next week looks like one of those classic sign of the changing season systems. If it comes together right, could be nasty cool on the northwest side by early Sept standards.