Hoosier

Noticed the 12z Euro had more MUCAPE than the GFS. Not a huge value by any means, but would probably suggest a bit more of a threat than the GFS. The timing of this would be atypical, but not unheard of. Severe threat could begin by daybreak in IL.

So you want snow, beavis? Just head to the Los Angeles metro area. Seriously though, I wonder how often something like this happens out there. Especially the blizzard warning. Not familiar with that area at all. URGENT - WINTER WEATHER MESSAGE National Weather Service Los Angeles/Oxnard CA 340 AM PST Thu Feb 23 2023 CAZ053-054-232100- /O.CON.KLOX.WS.W.0002.000000T0000Z-230224T1200Z/ /O.CON.KLOX.BZ.W.0001.230224T1200Z-230226T0000Z/ Ventura County Mountains-Los Angeles County Mountains- Including the cities of Lockwood Valley, Mount Pinos, Acton, and Mount Wilson 340 AM PST Thu Feb 23 2023 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY... ...BLIZZARD WARNING REMAINS IN EFFECT FROM 4 AM FRIDAY TO 4 PM PST SATURDAY... * WHAT...Winter Storm Warning through late Thursday with low elevation snow, strong winds and very cold wind chills. For the Blizzard Warning, heavy snow, winds gusting up to 80 mph, and near zero visibility. Total snow accumulations from 6 to 12 inches likely between 2000-4000 feet up to 2 and 5 feet of above 4000 feet. Isolated amounts to between 7 and 8 feet at higher elevations. Major mountains passes will be affected by significant snowfall. * WHERE...Ventura County Mountains and Los Angeles County Mountains. * WHEN...For the Winter Storm Warning, until 4 AM PST Friday. For the Blizzard Warning, from 4 AM Friday to 4 PM PST Saturday. * IMPACTS...Travel could be very difficult to impossible. Very strong winds could cause extensive tree damage. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. Travel should be restricted to emergencies only. If you must travel, have a winter survival kit with you. If you get stranded, stay with your vehicle. The latest road conditions from CalTrans are available by calling 1 800 4 2 7 7 6 2 3.

Assuming the strength of the low for early next week holds up, should get a decent wind event in the sub. And it's coming in strong, not a late bomber pulling into Canada, which will get the typically less prone southern sub into the game for high winds.

Lapse rates suck come Monday, but despite the poor instability, I expect at least an isolated severe threat to materialize in the Ohio Valley and potentially up to the southern Lakes. Very strong wind fields with good signals for a line or broken line of storms moving rapidly across the region. Damaging winds would certainly be the main threat, but I wouldn't rule out an isolated tornado. Directional shear isn't the greatest but there's some modest turning in the profiles, while speed shear is very good. This may get going relatively early in the day on Monday as well... maybe even potentially carrying over from the Plains.

Kind of depends on how you define heavy snowfall and significant ice, but assuming you have reasonable definitions for each, the snowfall is going to be more likely in general (maybe a different story as you head into the southern US, but not sure). So many failure modes for getting significant ice compared to a heavy snow. Although you wouldn't know it this year for a good portion of the sub lol

Would be wild on the west side of the low as it peaks in MO/IL. Extreme 850 mb winds. Obviously have to take this particular solution with a 1000 grains of salt, but I think it is an indication that the pattern could produce something pretty significant for somebody.

Sub 960 mb. Holy ****

00z Euro going ape. 965 mb low near STL. Not sure I've seen that modeled before.

Alluded to this in the storm thread, but figured I'd bring it over here for more detail. While the storm of 2/22/2023 will largely be forgettable for Chicago, this calendar day managed to pull off a combination that is quite uncommon. 1) have a high in the 30s 2) have 1"+ of precip 3) have less than 1" of snow The above combination has now happened only 14 times since 1884-85 (the first year that snow records are available), so it's about a 1 in 10 year occurrence over the long haul. For some comparison to a different season, Chicago has officially hit 100 or higher a total of 65 times. That is over 4 times as much as what occurred today. Of course it's not exactly apples to apples -- you either hit 100 or you don't, and that's that -- while this requires all 3 conditions of highs in the 30s, 1" precip, less than 1" of snow to be met. But you get the idea. Here is the list of all calendar days with highs in the 30s, 1"+ precip, and less than 1" of snow in Chicago. All of these would've largely been a cold rain or some combination of rain and freezing rain. Snow amounts for each date are listed last. Everything else is self explanatory. 11/10/1898: 36/33, 1.20", 0 4/16/1921: 36/31, 1.97", 0.1" 11/29/1930: 38/18, 1.19", 0.1" 3/12/1939: 35/31, 1.10", T 2/6/1942: 35/35, 1.98", T 4/19/1947: 39/36, 1.40", 0 1/18/1949: 35/17, 1.11", 0.2" 3/26/1959: 39/35, 1.40", 0 12/11/1983: 38/33, 1.03", 0 12/27/1988: 39/15, 1.03", 0.1" 4/4/2003: 39/32, 1.22", 0 2/16/2006: 37/22, 1.09", T 3/24/2016: 39/30, 1.09", T 2/22/2023: 36/33, 1.20", 0

Almost everywhere in northern IL is at least a degree or two above freezing now. Not gonna get a lot of ice melting off while 33-34 though, especially now with it being nighttime.

Indeed. Even half of that accreting in the main band would probably be like a 1 in 100 year event for a given location.

Gonna be a race as far as how much ice can melt before the winds pick up. One thing I'd say is that it seemed like the wind potential had trended downward a bit when I last checked into it. 50+ mph gusts would've been really bad.

I keep imagining if the icing was farther south to encompass more of the metro. Yikes.

This is an excellent summary. I think this event will also be remembered for the relative lack of impact on most roads throughout the bulk of the event (maybe things will get a little more questionable now with the loss of daytime). It's a good reminder that it really doesn't matter how mild the winter has been overall or in the lead-up to the storm when it comes to getting icing on elevated/colder objects, but it is a factor for road impacts.

Obviously but 18z GFS had an insane ice storm toward the end of the run. Some areas get freezing rain for like 36 hours. Catastrophic may not be a strong enough word.

Sucky day for anybody working outside in LAF. You already knew it was going to suck farther north.

It's torching just south of there in Crawfordsville. Tricky when you're near a large gradient.

Not totally sure, but it seems like it makes sense. All else being equal, something like 32/29 seems like it would be better for accretion than 32/32.

That is a neat observation.

One of the ugliest wx days I can remember in a while. Stuck at 34-35 degrees all afternoon with mod-hvy rain. I'd take heavy snow in April over this any day. Today is just nasty with no redeeming value since it's too warm for ice.

Gotta think that dews staying 2-3 degrees below freezing (at least per ASOS sites) and the brisk winds have been helping the cause.

Whatever areas end up on the northern side of the freezing rain zone with little/no sleet will have the worst ice and tree/powerline impacts. Those areas may remain a tick colder at the surface than the southern part of the freezing rain zone, plus the warm layer aloft won't be quite as warm.

The number to beat is 4" of sleet.

By default. It basically has no other choice but to trend weaker in this case.

About 976 mb, back in February 1960. The record low pressure at Little Rock is around 980 mb. So basically, the Euro is pushing the boundaries.