Central/Southern Plains Severe Weather Palooza (4/29 - 05/05)

[Chinook]

Convection-allowing models showing numerous storms from SE Colorado down into New Mexico, Texas, and Mexico. Each model shows the storms heading eastward, rather than stalling. This particular model has has a storm near Wichita Falls. The overall scenario looks very good, with mid-50's dew points, 0-6km shear of about 50 kt, and, as mentioned in the long SPC discussion, increasing storm relative helicity. By the way, the people of the region might freak out if they see a raindrop, let alone heavy rain or a tornado. Last rain over 0.01" at Tucumcari, NM was March 31st.

[andyhb]

Monday is trouble for S KS and OK. There will be early convection with the lead wave that passes through, but there is a signal across the board for recovery in its wake with upper 60s dewpoints returning towards the KS/OK border as a strong/progressive shortwave emerges from the Rockies. Should we see recovery and initiation, which I think is nearly certain in S KS and slightly less likely further south, it will take place in a very moist low level environment with hodographs favorable for tornadic supercells. There is regional severe event potential depending on how many storms develop.

[snowlover2]

New day 2 mentions EF3+ tornado possible.

Quote

 Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0101 AM CDT Sun May 01 2022

   Valid 021200Z - 031200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   OKLAHOMA AND SOUTHERN KANSAS...

   ...SUMMARY...
   A severe threat is expected to develop on Monday over the southern
   and central Plains eastward into the Ozarks. Large hail, wind damage
   and tornadoes will be possible Monday afternoon and evening. A
   marginal severe threat will also be possible across parts of
   west-central Texas and in the western Tennessee Valley.

   ...Southern and Central Plains...
   An upper-level trough will move eastward across the southern and
   central High Plains on Monday, as a 45 to 60 knot mid-level jet
   translates eastward through the base of the trough. At the surface,
   a low will move southeastward into northwest Oklahoma as a cold
   front advances southeastward across western Kansas and into western
   Oklahoma. By afternoon, a dryline will setup from a frontal triple
   point in western Oklahoma extending south-southwestward into
   northwest and west-central Texas. A warm front will advance
   northward across eastern Kansas and central Missouri. Surface
   dewpoints across the moist sector will be in the mid 60s F, where
   moderate instability is expected by afternoon. Convection is
   forecast to initiate ahead of the cold front from south-central
   Kansas into north-central Oklahoma during the late afternoon. Rapid
   thunderstorm intensification should occur with several clusters of
   strong to severe thunderstorms moving eastward from central and
   northern Oklahoma into eastern Kansas during the early evening.
   Isolated thunderstorms are expected further south-southwest along
   the dryline into parts of northwest and west-central Texas.

   The environment across the southern and central Plains may become
   very favorable for severe storms, depending upon early day activity
   shifting eastward away from the region. NAM forecast soundings from
   Wichita southward to Oklahoma City at 00Z/Tuesday are impressive
   loaded gun soundings. MLCAPE is forecast to be in the 2000 to 3000
   J/kg range, with 0-6 km shear from 50 to 60 knot. This is combined
   with 700 to 500 mb lapse rates near 8.0 C/km, and 0-3 km storm
   relative helicities of 450 to 500 m2/s2. This will be a high-end
   parameter space very favorable for supercells with large hail, wind
   damage and tornadoes. Hailstones of greater than 2 inches in
   diameter will be possible with the more intense supercell updrafts.
   As low-level shear ramps up during the late afternoon and early
   evening, tornadoes will be possible with the more intense
   supercells. Model forecasts show a strong low-level jet response
   across northeast Oklahoma. Supercells that develop to the west and
   northwest of the low-level jet should be associated with a threat
   for strong tornadoes, and an EF3+ tornado may occur. In addition,
   wind damage will be possible with supercells, and with organized
   short bowing line segments.

   A severe threat should develop south-southwestward into northwest
   Texas and west-central Texas to the east of the dryline, but
   convective coverage will be more isolated there. Large hail and wind
   damage would be possible with supercells that form in the late
   afternoon and early evening.

 

[Chinook]

5 minutes ago, snowlover2 said:

New day 2 mentions EF3+ tornado possible.

 

I'd say there is a strong case for a tornado outbreak in Oklahoma, as long as they can hit the 70's after the morning storms.

[cheese007]

30% contour added for central OK to just north of the DFW metro on D4

[WhiteoutWX]

Agree that Monday definitely has some higher end potential. Similar to Friday the best forcing with the wave will be in Kansas. Right now I’d say south central Kansas/north-central OK and eastward along the warm front present the best chance for initiation and tornado threat. I’m much more skeptical we see initiation further south into central Oklahoma given the track of the wave and residual capping, but not out of the realm of possibilities we could get a storm to go, which if it did would also be in a concerning environment.

[Quincy]

That early day convection can throw several variables into the equation. Some favorable and others potentially unfavorable:

Convection can leave outflow boundaries.

Early day moisture could also help limit mixing, keeping LCLs a bit lower and a slightly more saturated boundary layer.

Flip side, too much cloud cover could limit surface heating.

If early convection is too robust, that could augment wind fields a bit. 

With that said, this does show a regional signal, where even morning convection could have little to no affect, as rapid recovery takes place in the afternoon. 

I compared this setup to last Friday and synoptically, it is very similar.

Differences: 
Slightly faster. Convection seems likely by early afternoon in Kansas. The system is also a nudge farther south. 06z NAM was showing heights falling as far south as I-40 in Oklahoma by 18-21z. This should be a bit alarming. 

I also noticed less mid-level dry air and somewhat better moisture (think mean mixing ratios) through the column.

[Powerball]

Hi-Res models are now looking really chaotic with convection evolution this evening.

Some are even bringing a MCS through the Metroplex, with little activity in OK.

[Powerball]

46 minutes ago, Powerball said:

Hi-Res models are now looking really chaotic with convection evolution this evening.

Some are even bringing a MCS through the Metroplex, with little activity in OK.

It seems the Hi-Res models are struggling with whether the corfidi vectors or instability gradient will drive storm propagation, provided it does organize into a complex.

The former would support a more NE-ward trajectory, and the latter would support a more SE-ward trajectory.

[Powerball]

 

[Chinook]

WRF-NSSL really has a large cluster of storms, stretching some 150-200 miles along I-20. I wonder if this is possible.

[Powerball]

 

[Powerball]

 

[Powerball]

 

[weatherextreme]

Looks like the SPC thinking some intense tornado's might be possible from the current Tornado watch area.

 

Primary threats include... A few tornadoes likely with a couple intense tornadoes possible"

 

60/30 Probs.

[Powerball]

5 minutes ago, weatherextreme said:

Looks like the SPC thinking some intense tornado's might be possible from the current Tornado watch area.

 

Primary threats include... A few tornadoes likely with a couple intense tornadoes possible"

 

60/30 Probs.

Also, they're calling for hail up to 4" in diameter.

It's not often you see that with a watch box.

[Powerball]

FWD has added a severe wording to their grids tomorrow, with likely PoPs tonight and 50% PoPs tomorrow

[Powerball]

 

[Witness Protection Program]

A little bit here, a little bit there, maybe we can chip away a little at the drought.

[Witness Protection Program]

Aaand we've got a tor warn nw of Odessa

 

[Powerball]

 

[Powerball]

 

[Powerball]

5 minutes ago, Witness Protection Program said:

Aaand we've got a tor warn nw of Odessa

 

 

[Chinook]

3-d view of tornado warned storm at Andrews a few minutes ago

 

two updrafts

[Powerball]

 

[Powerball]

 

[Powerball]

"Wind-driven softball size hail"

 

 

[Powerball]

 

[Powerball]

 

[Powerball]