Chicago Storm

If things hold as modeled currently, it wouldn't be surprising. Especially with synoptic wind gusts over 45MPH likely as is.

high winds>heavy rain.

Haven't had a chance to put anything out regarding the upcoming period until now, but we are definitely seeing the most volatile weather pattern we have seen in many months coming up for the first half of November (And likely beyond), in part thanks to the MJO still rolling along and the PV on the move. The upcoming first 1/3rd of November, as everyone can see, will start off mild sub-forum wide. This is due to the continued -PNA, favoring Western US troughing through the period...Combined with little to no upstream blocking (+NAO). This pattern is fairly consistent with the progression of the MJO we have been seeing. This will lead to a fairly mild opening 8 days of the month across pretty much the entire sub-forum. Later in this opening 1/3rd of the month, things will trend cooler across northern portions of the sub-forum...Which is also when our members up in Duluth and Bo-land will see increasing chances for synoptic snows. This alteration of things will be due to larger scale changes, as the pattern will continue evolving with time as we eventually head into the middle 1/3rd of November. But more on that at a later time...

We have definitely entered the most active and wettest pattern we have been in since July. The next two weeks will have a parade of storm systems on the regular.

the world would be a better place if this guy didn’t exist. .

hoosier wins this one. .

Talk about a last minute/in event shift. Imagine if that were a few months from now… .

ORD was 79’d. 82 MDW. .

i enjoy drought when it could potentially lead to hotter temps (late spring/summer/early fall). drought at this time of year does nothing for me though.

The end of the month period is quickly approaching, and it will feature the most significant pattern change we have seen since the spring and an MJO helping to aide in the change, as it continue to progress through phases 5-7. The -NAO/pseudo West Coast rex block pattern/+PNA that has been in place for this middle 1/3rd of October will be breaking down, being replaced by significant and deep Western/Central US troughing for a good portion of the final 1/3rd of October, with increasing GOA/Aleutian troughing (+EPO/WPO) as well. This will all lead to the increasingly advertised bout of Indian Summer conditions, from late this week through very early next week. In addition to the period of mild temps, there could very well be some level of severe weather threat with the significant ejecting through the Central US on Sun/Mon (Pending instability/moisture return issues in the wake of the current trough). Beyond this things will be in flux a bit, with a secondary trough sliding into the west and then likely ejecting east through the Canadian Prairies and the Central US...But small differences could determine whether there's a second bout of Indian Summer conditions or more seasonal fall like conditions, with another associated storm system as well.

GFS being the GFS. A lot in flux though coming up for the final 1/3rd of the month and into early November, with the biggest pattern change we’ve seen since the spring and MJO moving as well. .

First T of snow on the new season today in Chicago and Rockford.

Chicago area folks should be watching the potential for the first flakes of the season on Monday, associated with an inverted trough featuring swinging through the Great Lakes. (Along with portions of WI/MI/N IN/N OH).

I was surprised they had gone with one yesterday, due to the likelihood of clouds being an issue. Early next week is the real widespread freeze, and likely a hard freeze at that. .

Negligible cape, but a high shear/forced environment. A day like this many times will not “do it” and will almost always fly under the radar. On the rare occasion it works out, this is what you get.

Nothing really supported what is occurring right now. .

Couplets galore right now showing up on TMKE. .

Yea, not going to blame them on this one for once. .

That’s is…unexpected. .

The first 1/3rd of this month has essentially panned out as expected. Looking forward to the next 1/3rd of the the month (11-20th), we are going to see some changes on tap. For the first time in a while we will be seeing a formidable -NAO, from late this week through early next week. At the same time, we will be seeing a rex block take shape along the West coast the middle of this week, continuing into early next week. There will also be the re-introduction of Aleutian/GOA troughing, which had recently relaxed a bit. This will lock in a significant trough across the Hudson region, our sub-forum and the Northeast. In the wake of mild temps today-Wed and some rain chances Tue/Wed, this upcoming period looks chilly and dry overall. During this period we'll likely see several additional chances for frost/freeze conditions across the sub-forum, as well as the chance for some synoptic flakes across portions of the MW/GL.

i don’t even know how one comes up with such a splotchy map, unless it’s some random ms paint drawing. .

this isn’t looking so hot right now. .

one that melts on contact. .

For the first 1/3rd of October (Through close to the 10th-ish), things look to remain as they generally have been. Feels like I've said this about 50 times over the past few months, but for this first chunk of October we will see a continuation of the general pattern we have seen dominate a good portion of the summer and the pattern we are currently in. The constant troughing centered around the Hudson/Greenland, which has been relentless, will continue to be the focus for weather in most of our sub-forum. All in all, this will lead to generally zzz and dry weather activity wise, and a fall-like temperature regime for the first 1/3rd of the month. One wildcard to watch will be the potential for the splitting of the newly formed seasonal PV in the Arctic. The GEFS were showing this in the very extended, and as time goes on, they continue to latch onto this idea even more-so. That could alter things for the end of the first 1/3rd of the month and second 1/3rd of the month.

Everything has panned out pretty much as expected for mid to late Sept...With the heat wave in mid Sept, followed by a return to a similar pattern as to what has dominated much of the summer (Pictured below). Oct thoughts to come in a later post, but not much change expected to start.