andyhb

6 minutes ago, WaryWarren said:

He's too busy posing for selfies in Rolling Fork.

To be fair, he also has raised a lot of money for the community. You can't fault him for that.

Come on, seriously now. You just don't see output like that from the 3 km NAM.

HRRR solutions later are likely going to be pretty nuts if the 3 km NAM is already this aggressive across the warm sector (with supercellular storm modes).

Early 3 km NAM runs certainly don't do anything to suppress this potential. Impressive parameter space across the entire warm sector.

Think we're going to need a specific thread for 4/4 given the potential magnitude of Tuesday's threat, but we have a large D7 15% area outlined in the latest D4-8.

Quote

However, on Tuesday, as the upper trough ejects
   east and spreads intense deep-layer southwesterly flow over the
   Lower/Mid-MS Valley to the Ohio Valley, a sharp cold front will
   surge east. Rich gulf moisture across a broad warm sector will
   supply plenty of instability, and potentially widespread severe
   thunderstorms will once again be possible across the Mid-MS/Lower OH
   Valley toward the Mid-South and TN Valley.

Quote

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0236 AM CDT Wed Mar 29 2023

   Valid 311200Z - 011200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF THE MID-MISSISSIPPI VALLEY TO THE MID-SOUTH...

   ...SUMMARY...
   Potentially intense and widespread severe thunderstorms are expected
   Friday afternoon into the overnight hours across portions of the
   Middle Mississippi Valley and Mid-South vicinity, eastward to the
   Lower Ohio and Tennessee Valleys. Damaging gusts and tornadoes will
   be the main hazards with this activity.

   ...Arklatex to the Mid-MS Valley and eastward to the OH/TN
   Valleys...

   Widespread, regional episode of severe thunderstorms is possible on
   Friday.

   An intense mid/upper trough is forecast to eject eastward across the
   Plains to the central U.S. on Friday. Intense deep-layer
   southwesterly flow will accompany this system, with a 100+ kt 500 mb
   jet expanding over much of the Midwest. As the upper trough deepens
   during the afternoon and evening, a 60-70 kt southwesterly low-level
   jet will overspread much of the risk area. These flow fields will
   favor a fast-moving squall line shifting across the Mid-MS
   Valley/Mid-South toward the Lower OH and TN Valleys. 

   At the surface, strong southerly low-level flow will transport 60s F
   dewpoints northward. Near-60 F dewpoints are expected as far north
   as eastern IA to northern IL and then central IN as the surface low
   tracks east/northeast from IA early in the day, to southern Ontario
   by Saturday morning. While some questions remain regarding moisture
   with north and east extent into the OH Valley, forecast soundings
   indicate at least a few hundred J/kg MLCAPE will exist during the
   evening as far east as the I-65 corridor in KY/TN. Given intense
   flow fields, a threat for damaging gusts will persist from MO/IA
   into the Lower OH Valley.

   Across IA/MO, initial supercell development is possible near the
   surface low/triple point. Fast moving storms may produce possibly
   significant damaging gusts and tornadoes. Upscale growth into a QLCS
   is expected to occur rapidly given strong forcing/vertical shear.

   Further south into the Mid-South and vicinity, large-scale ascent
   will be somewhat weaker further removed from the upper trough.
   However, flow fields will remain intense and a mixed mode of
   supercells and linear convection is expected. All severe hazards
   (damaging gusts, tornadoes and isolated hail) are expected by late
   afternoon into the evening hours.

   ..Leitman.. 03/29/2023

Somehow the 00z Euro came in and outdid last night's 00z run in terms of insanity. A 971 mb low with plenty of moisture access. Absolute bomb.

Will just report my tweet here for the ensemble means, which all indicate that Tuesday could be a big day.

1 hour ago, CheeselandSkies said:

Also notable that the 00Z NAM forecast dewpoint in east-central Iowa for 21Z tomorrow is 7 degrees. In 48 hours that's supposed to be nearly 60.

In fact, last couple of NAM runs (especially 00Z) suggesting the northern end of this setup might struggle with moisture return moreso than previously thought. That cold high pressure tomorrow is really gonna wipe it out. OTOH it is the NAM so... And the precip fields even appear to be popping an arc of semi-discrete convection in that classic sweet spot just southeast of the surface low.
 

Probably because it's almost -20 degrees at 500 mb and below freezing at 700 mb yielding extreme 0-3 km CAPE and low-level lapse rates.

12z GFS/GEFS is also incredible in the Tuesday-Wednesday window next week.

00z Euro for 4/4, holy mother of god...

5 minutes ago, cyclone77 said:

I'll be down at Lake of the Ozarks Thu/Fri so no chasing for me with this.  Will definitely be following it though as it looks pretty interesting.  Nice to see a setup in the forecast.  

You could take a... "detour" to Eastern AR perhaps.

500 mb presentation on the Euro is a classic for a significant severe event in the Midwest.

CSU MLP is going off for Friday with a massive 45% hatched area.

That’s a very large 30% in the D5.

Strong tornado ongoing WNW of Tuskegee AL.

00z models look nasty for Friday in portions of the sub-forum. A couple of them have what would probably be a significant severe weather outbreak from the Mid MS Valley to the western Lakes.

Some very high end solutions here in the GEFS.

And now up to 21...

Report from another forum of the situation in Amory MS.

Death toll looks to be up to at least 14.

7 dead per county coroner in Sharkey Co. MS (Rolling Fork area).

That was a devastating hit on the northern portion of Amory.

Absolutely violent tornado heading for Amory, and that is not a small town.

Debris above 30k feet with this thing, very likely violent.

Large wedge tornado in progress near Rolling Fork, MS.

06z HRRR, holy mother of god…

SPC outlook makes it seem like they were quite close to a high risk, but the disagreement from the CAMs held them off.