Chicago Storm

LOT AFD for @Hoosier... "IN FACT, LAKE TEMPERATURES OF +10 TO +11C AND 850MB TEMPERATURES OF -6 TO -7C AS WELL AS INVERSION HEIGHTS PUSHING 11,000-12,000 FEET WILL GENERATE AS MUCH AS 250-350 J/KG OF LAKE-INDUCED CAPE FROM LATE TUESDAY AFTERNOON THROUGH EARLY WEDNESDAY MORNING, LEADING TO CONCERN THAT LAKE ENHANCEMENT TO SNOW MAY "OVERACHIEVE" IN SPITE OF MARGINAL SURFACE TEMPERATURES. INTERESTINGLY, THE 12Z HREF SHOWS SPLOTCHY 20-30% PROBABILITIES OF SNOW RATES >1"/HR BETWEEN 2-3 PM TUESDAY AND 3-4 AM WEDNESDAY ACROSS THE NORTHERN CHICAGO SUBURBS. PERHAPS MORE CONCERNING IS THE 12Z HREF 24-HOUR LOCAL PROBABILITY-MATCHED MEAN QPF OF 0.75-1.00" ACROSS LAKE, COOK, AND NORTHEASTERN DUPAGE COUNTIES. WHEN APPLYING A STANDARD 10:1 SNOW RATIO, IT'S EASY TO SEE HOW SNOW TOTALS MAY GET OUT OF HAND. HOWEVER, WITHOUT A PERSISTENT BAND HITTING THE SAME AREA FOR HOURS AND HOURS, IT MAY BE TOUGH TO TRULY REALIZE THE SNOWFALL AMOUNTS ADVERTISED BY INDIVIDUAL HIGH RESOLUTION CAMS THAT INFORM THE HREF. FOR NOW, WE WILL CAUTIOUSLY ADVERTISE AN ADDITIONAL 2-3 INCHES OF SNOW ON TOP OF WHAT FALLS IN THE MORNING KEEPING IN MIND OUR FORECAST MAY BE WAY TOO LOW."

In the LOT CWA (Even the MKX CWA)? Yea, I'd agree.

Easy toss. There was hope that the elevation correction earlier this year would fix the overzealous LE output, but clearly it didn’t. .

There’s going to be several periods of snow/mixed precip between Monday and Thursday. .

Had a few heavier snow showers while both at home and at ex home today, some of which were enough to dust all non-paved surfaces with a tenth or two of snowfall accumulation. .

Two issues with that… Most guidance did show snow that far north, and most guidance did show the potential for more snow than offices down there were forecasting, was was ranging from no snow up to 0.5”. On the flip side…There was very little support among guidance for anything really over 3” or so. So nonetheless, that band of 4-8” is still a surprise in the end. There was actually an event like this, which I believe may have been last winter, down in East-Central Illinois. It also occurred overnight/early morning, and dropped a localized/unexpected area of 6”+ snow.

And to follow up on the follow up... Below is the list of all years on record in Chicago to feature a November with 4.0"+ total snowfall. As you can see, the following December is usually split potential for above/below normal snowfall, and usually seasonal total snowfall ends up above average. 1891: 6.8"......5.5"......26.8" 1893: 7.5"......12.1".....48.2" 1895: 14.5".....3.4"......52.5" 1896: 4.2"......1.3"......41.2" 1927: 14.9".....10.0".....29.3" 1940: 14.8".....4.1"......49.0" 1941: 5.2"......1.7"......40.5" 1947: 6.2"......6.4"......40.6" 1950: 7.0"......27.1".....60.0" 1951: 14.3".....33.3".....68.3" 1953: 7.6"......5.4"......28.4" 1954: 5.7"......8.2"......44.2" 1955: 5.9"......2.1"......26.2" 1959: 6.6"......10.4".....44.1" 1972: 5.5"......10.3".....66.9" 1974: 5.1"......16.3".....53.7" 1975: 10.8".....11.7".....53.3" 1977: 6.3"......19.2".....64.3" 1978: 7.1"......31.4".....95.3" 1980: 5.1"......9.7"......48.8" 2002: 4.7"......8.0"......42.2" 2004: 5.1"......0.6"......29.0" 2015: 11.2".....4.5"......63.5" 2018: 12.7".....1.4"......44.8"

To follow up on this... November snowfall totals in Chicago the past 20 years. As you can see, it has generally been all or nothing, with only a few in between. 2002: 4.7" 2003: T 2004: 5.1" 2005: 1.9" 2006: 0.4" 2007: 0.3" 2008: 0.6" 2009: T 2010: T 2011: T 2012: T 2013: 0.9" 2014: 2.8" 2015: 11.2" 2016: T 2017: 0.1" 2018: 12.7" 2019: 3.7" 2020: 0.7" 2021: T

A normal November has snowfall opportunities. We're just not used to it.

Watch next week. Not a slam dunk given several moving pieces, but potential is there. Best looking November pattern for widespread cold and some snow potential across such a large portion of the sub-froum, since Nov 2019.

the deed has been done.

As usual, for the non-thread worthy events.

Record broken here at ORD. Peak of 76 so far.

Every November day needs to be like today. .

An fyi... The GFS is set to be upgraded on Nov 29th.

That later time has come. The pattern has continued to evolve, and as such, will bring the most widespread/consident and coldest temperatures of the season to the region for the upcoming middle 1/3rd of November. Additonally, we could potentially see a synoptic snow opportunity or two across the region... However, with such a volatile pattern and a ton of moving pieces, it isn't guranteed. Nonetheless, the upcoming pattern is in large part being forced by the continued movement of the MJO through phases 7-8-COD and movement/streching of the SPV. The middle 1/3rd of November will predominately feature conistent/deep troughing from Canada down through the heart of the CONUS, allowing for the aforementioned colder temperatures to take up residence across much of the region for this period. Additionally, while a -EPO (GOA ridging) will be in place for this period, the setup will be favorable for waves to break through the ridge and top the ridge, eventually making it down into SW Canada and the Western US. This is where storm system opportunity could possibly arise for the region, but again...it's not a given, due to the deep mean trough across Canada/CONUS. Moving forward into the last 1/3rd in November, it will be interesting to watch how things evolve. The MJO will is projected to propogate from the COD and back into phases 5-6. This would support a return to more mild conditions. However, there is also support for continued movement/alteration of the SPV, which could potentially take up residence in Northern Canada by the end of the middle 1/3rd of Nov/early last 1/3rd of November. That could potentially combat things. More on the final 1/3rd of November eventually...

Cool/cold and dry… As bad as it gets. .

Still within high wind warning criteria, though. You know I'm a stickler with many things though...

NWS sort of being redundant, issuing severe t’storm warnings for the forced line of convective showers, while already having a high wind warning in effect that covers it. Nonetheless, looks like area wide in the metro has experienced 45-60MPH wind gusts overnight and this morning. DPA was a luckily isolated location, having a 77MPH wind gust with the line of showers a bit ago.

I dig the large leaves, makes it have a tropical-esque appearance.

Pines are my second favorite type tree. Red pines and white pines, in particular.

It depends on how hardy of a palm tree it is. Less hardy ones need to be boxed with a heater, while the most hardy may survive with a garden blanket and a frost blanket.

There ya go. I have several recommendations when the time comes.

Still have some things going in the garden out here in the suburbs as well. .

sounds like we need a mod. i’ll volunteer. .