Chicago Storm

For myself, if I had to pick a single day it would be 6/20/2021. Chasing a QLCS 10 minutes from home at 11PM and being hit by an EF-3 tornado easily takes the cake, and will be hard to top. As for other events by weather type... ...Warm Season... Damaging Winds: 8/23/2007 derecho. This derecho raked across portions of the Midwest on this day. Walking home while the derecho hit, with tree and other debris flying around, was an experience for sure. Power was out for four to five days, with significant and widespread tree/property damage in the area. Hail: 6/26/2019. An isolated severe t'storm briefly perked up as it crossed the lake breeze, producing 2.25" hail and 50-60mph winds while home. This marked the biggest hail I have witnessed, while home or out chasing. Tornado: 6/20/2021. Chasing a QLCS about 10 minutes from home at 11PM and being hit by an EF-3 tornado is as good as it gets. Then, being in the damage path all night long, and out drone surveying damage the next day. An honorable mention goes to 10/4/2013, which was the day of the Wayne, NE EF-4 tornado. We ended up being hit by the outer edge of the ciculation, having windows blown out on our vehicle, while I was hanging out the window trying to hold my GoPro to the hood. Heat: 7/4-7/2012 heat wave. The hottest temperatures and longest duration of extreme heat I've experienced, with several days in a row of 100+ high temps. Being that the 4th of July is my favorite holiday, the overlap was perfect. ...Cold Season... Snow: GHD 1. It hit the marks for most snowfall in a single storm and 24hr period I've experienced, some of the top snowfall rates I've witnessed, and the most TSSN I've experienced in one storm. The wind, snow and accumulation combo easily puts it at the top of the list. Ice: I have yet to experience a significant ice storm, unfortunately. Cold: 1/30-31/2019. Although brief, this event featured the coldest temperatures and wind chills I can recall experiencing. Honorable mention would be 1/5-7/2019. The duration was much more significant versus severity, when compared to the 2019 event.

Quality info here.

You're still out here by ORD?

They went 2-5" in the WWA, so they are pretty close to it. I guess it's time to pull up BUFKIT and check it out.

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.