Chicago Storm

Friday's dust storm was quite an experience... Never thought I'd ever report a DS at ORD.

Peak conditions...
ORD: DS 1/2SM G50MPH
MDW: +DS 1/4SM G60MPH

Info...
•The dust storm warning for Cook County was only the second ever issued for the county. 
•It was the first ever dust storm warning issued for downtown Chicago.
•Per Frank Wachowski, the last dust storm of this severity in the metro area was way back on May 10th, 1934.

ORD had a high temp of 94° on Thursday, which broke the record high maximum temp for the date of 91° (1962).

Chicago/O'Hare had a high temperature of 94° on May 15th, which broke the record high maximum temperature for the date of 91° (1962).

+DS 1/4SM G60MPH at MDW.

Should have been issued a half hour ago.

1 hour ago, sbnwx85 said:

New MD out for Illinois. Monster hail possible.

Mesoscale Discussion 0794
   NWS Storm Prediction Center Norman OK
   0322 PM CDT Thu May 15 2025

   Areas affected...Parts of central and northern Illinois

   Concerning...Severe potential...Watch possible 

   Valid 152022Z - 152215Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Large to very large hail and severe winds will be possible
   with supercells that can develop later this afternoon. Watch timing
   is uncertain but is possible later this afternoon.

   DISCUSSION...Cumulus are developing along an eastward moving dryline
   near the Mississippi River. Ahead of this boundary, a strongly
   unstable airmass is in place (low 90s F temperatures and mid 60s to
   low 70s F dewpoints). With the strongest mid-level ascent to the
   northwest of the region, timing of storm initiation as well as storm
   coverage are uncertain. However, given the lack of MLCIN, a isolated
   to widely scattered development appears possible later this
   afternoon. 45-55 kts of effective shear will support supercells. The
   primary hazards will be large to very large hail and severe winds.
   The tornado threat is expected to be less than farther north given
   the slightly veered low-level winds and more sizable
   temperature/dewpoint spreads at the surface.

   ..Wendt/Mosier.. 05/15/2025

only watch possible?

1 hour ago, iBrian said:

Has ORD hit a record high for the date, yet? My thermo was stuck at 93 while driving around.

Yes, it hit at least 93.

Most of the high res guidance has this now.

MODS, given the increasing severe weather threat on friday across the southern portion of the subforum, can we add 5/16 to the title?

To add the the above, if the Euro, which is sort of alone in with the idea right now, has any clue... Things could be more interesting southward.

Check out the significant dry line/bulge it depicts pressing across N and C IL. If frontal convergence can tighten up a bit more, and if that scenario were to be more realistic and gain support, then...

4 hours ago, CheeselandSkies said:

What doesn't look great about it to you? There are some potential failure modes to be sure but I think it checks a lot more boxes than that day did.

*Edit Annnnnd 12Z 3K NAM coming in hot (unlike any of the CAMs at this range for 4/28). Unusual for this model to resolve semi-discrete convection like this. These simulated cells are moving through a strongly unstable and sheared environment. The solution verbatim would also resolve a lot of the timing issues that have been shown on the coarser models (especially the GFS).

But, it really doesn't check more boxes, in a way. Capping, lack of frontal convergence (roughly south of the IL/WI border latitude), and the fact that the best dynamics are lifting further north into the Midwest/Western Great Lakes, are all significant concerns. The SPC overlooked concerns with that previous event and went with a balls to the wall approach...and failed. There is zero reason to do that once again this time across areas that are clearly more conditional.

Highest coverage of activity will most definitely be across MN/NE IA/WI, though I think quality will be a bit more in question there. South of there, it's really too conditional overall. S Wisconsin may have the greatest shot of the most interesting activity, as there may be a more optimal overlap of everything there. South of there, sure, the environment is great across IL, but the three aforementioned issues will be problematic.

Initial Day 3 outlook was surprisingly underwhelming. Gun-shy after the one they put out for April 28? But this setup looks a lot more concerning simply from a trough geometry standpoint.

Not fine according to 18z GFS.
Thursday May 22 (some spots stuck in the mid to upper 40s):

The day before Memorial Day (stuck in the low to mid 50s):

Backdoor cold front (and daily lake cooling) gonna suck.

On 5/2/2025 at 11:24 AM, Chicago Storm said:

i troll spartman, and then guidance flips.

i see how it is...

canceled.

On 4/30/2025 at 12:20 PM, Chicago Storm said:

another nice month on tap.

re-instated.

On 4/30/2025 at 12:20 PM, Chicago Storm said:

another nice month on tap.

i troll spartman, and then guidance flips.

i see how it is...

Another nice month? April was a washout. 
Even with a garbage blocking pattern taking place this weekend into next week....

another nice month on tap.

Topped out at 84° at ORD yesterday, which is the first official 80°+ day of the year for Chicago.

It was also just shy of a record high for the date as well.

Classic solid EML/deep summer setup tonight.

A heat burst is occurring in S IA currently, with anvil showers across N MO/S IA.

Oskaloosa, IA went from 76/64 to 81/43, with winds gusting to 69MPH.

looks like a non-event around here.

a marginal is questionable enough as it is, let alone an enhanced into portions of the CWA.

On 4/23/2025 at 5:49 AM, Baum said:

striking how old the years of the previous winters were with so little snow.

On 4/23/2025 at 5:56 AM, A-L-E-K said:

lakefront wx site?

Here's the list with OBS locations added.

I should note that 9 out of 10 of RFD's least snowy seasons also occurred between 1900 and 1940. So, it was just a period filled with a lot of clunkers. RFD's least snowiest season on record was 2.8" during the 1906/07 season.

Least Snowiest Snowfall Seasons
1. 9.8" - 1920/21 (Downtown/Loop)
2. 11.5" - 1921/22 (Downtown/Loop)
3. 12.0" - 1936/37 (South-side/U of Chicago)
4. 14.3" - 1948/49 (MDW)
5. 17.6" - 2024/25 (ORD)
6. 18.0" - 1898/99 (Downtown/Loop)
7. 18.2" - 1901/02 (Downtown/Loop)
8. 18.9" - 1924/25 (Downtown/Loop)
9. 19.0" - 1914/15 (Downtown/Loop)
9. 19.0" - 1912/13 (Downtown/Loop)

The 2024/25 snowfall season will finish as the 5th least snowiest on record for Chicago. Also of note, is that with this being the case, the season of 2011/12 has now dropped out of the top 10.

Least Snowiest Snowfall Seasons
1. 9.8" - 1920/21
2. 11.5" - 1921/22
3. 12.0" - 1936/37
4. 14.3" - 1948/49
5. 17.6" - 2024/25
6. 18.0" - 1898/99
7. 18.2" - 1901/02
8. 18.9" - 1924/25
9. 19.0" - 1914/15
9. 19.0" - 1912/13

Suicide weather yesterday, it returns tomorrow. TWC/Wunderground now says it might as well include some rain if they have maintained overcast skies for tomorrow over the past several days. So much for the 1st dry weekend of Spring 2025. 

Normally we would have at least one dry weekend or two every Spring, but I feel that this is just not going to be our year. Even wet springs like 2011 had some dry weekends.
The last time it rained EVERY SINGLE WEEKEND the entire Spring was in 2019. 

madwx a solid new addition for mid/longer range views.