Severe Weather 3-13 through 3-16-24

[cheese007]

Got another advace-forecast with a D6 15% including DFW and part of the Austin metro. Something to watch

[Ed, snow and hurricane fan]

Now a Day 4 15% risk in a similar area.  NWS FWD awaits the event moving into the range of the hi-res models.  ~40 knots deep shear, which is enough with a forecast near 2500 J/Kg MLCAPE and near 8 C/Kg mid level lapse rates (producing almost 60 TT) but low level shear only about 10 knots probably means not a giant tornado threat.  Which is what NWS said.  Not good news, we're going to Euless to visit my Mom, 90 years old.  May suggest a rental car to my wife.  We leave Wednesday, which will be in range of hi-res models.

[cheese007]

Slight risk added for the 13th as of today, with a large expansion of the risk area + hatching added for the 14th. Below is the discussion for the latter

SPC AC 120731

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0231 AM CDT Tue Mar 12 2024

   Valid 141200Z - 151200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE MIDDLE
   MISSISSIPPI VALLEY INTO EASTERN OKLAHOMA...EAST TEXAS...AND THE
   LOWER MISSISSIPPI VALLEY...

   ...SUMMARY...
   Strong to severe thunderstorms are possible across a large area from
   the Middle Mississippi Valley into eastern Oklahoma, East Texas, and
   the Lower Mississippi Valley on Thursday.

   ...Synopsis...
   A surface low is forecast to be over the NE/IA/MO border vicinity
   early Thursday morning, with a cold front extending southwestward
   from this low across eastern KS and central OK into the TX Hill
   Country. An expansive warm sector is expected to be in place east of
   this cold front, from the Mid MS Valley into the southern Plains and
   Lower MS Valley early Thursday morning, supported by the previous
   days' return flow. Showers and thunderstorms may be ongoing in the
   vicinity of a warm front extending north-northeastward from the
   surface low, but much of the warm sector is currently expected to be
   free from any early period storms.

   This broad warm sector is expected to destabilize throughout the day
   with two primary corridors of severe thunderstorms potential, one
   near the surface low from southern IA/northern MO into west-central
   IL and another farther south from eastern OK and east TX into LA and
   AR.

   ...Southern IA/Northern MO/West-Central IL...
   Upper 50s dewpoints are expected south of the warm front throughout
   the period. Despite this somewhat modest low-level moisture,
   moderate to strong buoyancy is still anticipated early in the
   afternoon as surface temperatures climb into the low 70s, supported
   by cold mid-level temperatures and resulting steep mid-level lapse
   rates. Low-level convergence near the surface low and warm front
   will likely result in convective initiation amid vertical wind
   profiles that support supercells. There may be a tendency for storms
   to move north of the warm front over time, but enough residence in
   the warm sector is anticipated for some storms to reach maturity.
   Any mature supercells would be capable of all severe hazards,
   including tornadoes, strong gusts, and very large hail. 

   ...Eastern OK and East TX into LA and AR...
   Weak surface troughing will likely interact with an increasingly
   unstable airmass across the region during the afternoon, with
   convective initiation anticipated around 18Z across southeast OK and
   northeast TX. Given robust buoyancy and moderate vertical shear,
   initial development will likely be supercellular and capable of all
   severe hazards, including very large hail. How the convection
   evolves after the initial more discrete storms remains uncertain,
   with some potential for development into more linear structures
   given the front-parallel deep-layer vertical shear. If upscale
   growth is realized, the resulting convective line would then push
   eastward into AR and LA, with some potential for damaging gusts.

   ..Mosier.. 03/12/2024

[cstrunk]

Tomorrow evening certainly looks interesting in the extreme NE Kansas area.

[Ed, snow and hurricane fan]

3 hours ago, cstrunk said:

Tomorrow evening certainly looks interesting in the extreme NE Kansas area.

Cap almost holds, but does break and STP(cin- MLCAPE higher than SBCAPE) almost 5 per 3km NAM just N of MCI tomorrow evening.  My BIL is coming down to DFW from MCI tomorrow.  SWODY 2 has hatched hail, not hatched tornadoes MKC area.  Thursday's SPC Southern Sig Severe looks more conditional, HRRR breaks cap near DFW, NAMs not so much.  Driving to Euless tomorrow.  FV# may be showing a supercell with a couple of hooks (maybe my imagination) a couple of counties NE of DFW Thursday late.  We decided not to rent a car.  My brother and my sister in-law will be safer in DFW.

 

Re-SWODY2's next update as SWODY1, I suspect Sig Severe for tornadoes as well as the existing one for NE Kansas.

 

 

[cheese007]

ENH added for D1 around KC but no sig-tor hatching as of 8AM

[Quincy]

Kansas and Missouri are the areas to watch late this afternoon into this evening. A tornado threat could develop near I-70 along the warm front, but we’ll have to see how narrow the warm sector is and if storms outrun the front. 

Right now, dew points are confined to the 40s across much of Kansas, but lower 60s dews have surged into northeastern Oklahoma. 

At one point there was some concern about convective initiation near the dryline in Oklahoma. That seems unlikely at this point. A non-zero shot, as a few outlier models (6z RGEM) still try to convect there. Very shallow moisture will likely preclude any development. Even if something were to initiate, it would likely be short lived. 

Tomorrow looks interesting over a larger area with a broad warm sector anticipated. Evolution of overnight storms into early tomorrow morning will be a factor to watch. Stay tuned. 

[Ed, snow and hurricane fan]

80% SPC watch probs NE Kansas and NW Missouri.  By NE Kansas, I mean not just a corner, meso bubble almost to Hays.

[Chinook]

A few storms developing near Topeka's radar look like they could get going into supercell mode.

[Sydney Claridge]

59 minutes ago, Chinook said:

A few storms developing near Topeka's radar look like they could get going into supercell mode.

Looks like they have. This looks like some serious rotation near Alta Vista, KS:

[nwohweather]

Looks like they have. This looks like some serious rotation near Alta Vista, KS:

Holy God that’s a beast. They have it on the weather channel right now

[SchaumburgStormer]

This thing is probably picturesque. Awesome

radar presentation. 

[SchaumburgStormer]

PDS warning, then the new one upstream is “radar indicated rotation”. They can probably update that, it is for sure producing 

[Chinook]

I think this was the highest of the measured wind speeds

 

[cheese007]

Vince Waelti on YouTube seems to have a good angle 

[Sydney Claridge]

9 minutes ago, SchaumburgStormer said:

This thing is probably picturesque. Awesome

radar presentation. 

It’s also pretty interesting to see all of this happening near a radar site, too.

The storms over the Kansas City metro also bear watching; the atmosphere there (per SPC Mesoanalysis) also seems primed for potential tornadic activity. Fortunately those storms seem to be behaving themselves (rotation-wise), but I did notice some weak rotation around Shawnee. It’s not really “behaving” though; there’s a hailstorm in the KC metro now.

[Chinook]

a couple of possible tornadoes now

[Chinook]

this was a tornado by a spotter report

[Chinook]

new confirmed tornado at Hoyt

Quote

HAZARD...Damaging tornado and baseball size hail.

SOURCE...Weather spotters confirmed tornado northwest of Hoyt.

IMPACT...Flying debris will be dangerous to those caught without
         shelter. Mobile homes will be damaged or destroyed. Damage
         to roofs, windows, and vehicles will occur.  Tree damage is
         likely.

 

[cheese007]

10% tor added for D1 and a slight risk added for Austin/San Antonio area for D2

 

[Quincy]

12z soundings show an unseasonably unstable air mass already in place (for early day, mid-March standards) with some capping. 

However, guidance erodes capping quite quickly with some model solutions initiating storms prior to midday. 

Wind profiles aren’t ideal, but should be sufficient for initial supercells. Given the background environment, you could see a few intense supercells form. I’d expect complex storm modes/interactions with time, but if a storm can thread the needle, significant severe is certainly a possibility. 

[Stx_Thunder]

2 hours ago, cheese007 said:

10% tor added for D1 and a slight risk added for Austin/San Antonio area for D2

 

SPC is likely going to expand that current D2 Slight Risk south-east going into tomorrow. GFS & Euro showing sufficient DL & effective shear around 50 Kts over southern half of TX Friday afternoon/evening (Del Rio - Houston line, south), with an unusually backed south-easterly 850mb flow happening right ahead of a slowing/stalling front. Because of a cutoff 500mb Low out west that’ll be edging a little closer by then with stronger shortwaves aloft in the SS obviously trailing in from it.

But even through Friday night over STX, latest runs are showing CIN weakening more through the night with more storms popping up over the Rio Grande plains around Laredo overnite, going east. And with all that projected positive 850mb theta advection going on beneath steep ML lapse rates and sufficient shear, could still have some pretty powerful storms & supercells going on overnite into Saturday. Even if a little elevated.

I see they also have a D3 marginal risk outlined over Laredo area toward San Antonio. But that’ll probably also be upgraded to a slight risk or at least in Deep STX if the front is still hanging around here until early Sunday. Can be earlier frontal push if mature MCS happens Saturday morning (which is good possibility seeing these things in the past around here). But this whole setup with a cutoff Low out west ahead a very modified warm sector in mid March (already 70F+ DPs on TX coast this morning), is unusual to say the least. There’s definitely going to be a lot of built-up instability that storms can tap into over southern half of TX (with enough lift), Friday afternoon/night.

[Ed, snow and hurricane fan]

Visiting family in HEB area of DFW.  Expecting storms to fire pretty much overhead late afternoon and mature as they move E past us.  3km NAM shows >4000 J/Kg MLCAPE just E of here.  I expect the storms to mature quickly, updraft helicity after storm initiation down here less impressive than I'd have expected.

 

If I see anything cool, I'll snap storms to the E lit by the early evening light and post them.

[cheese007]

D1 sigtor added

[cstrunk]

Man, the last few runs of the HRRR look pretty nasty for a pretty big area of NE TX, E OK, and NW AR. Lots of individual cells/supercells this afternoon/evening. 

[cheese007]

50/30 tor probs

URGENT - IMMEDIATE BROADCAST REQUESTED
   Tornado Watch Number 42
   NWS Storm Prediction Center Norman OK
   1110 AM CDT Thu Mar 14 2024

   The NWS Storm Prediction Center has issued a

   * Tornado Watch for portions of 
     Central/eastern Oklahoma
     North-central Texas

   * Effective this Thursday morning and evening from 1110 AM until
     600 PM CDT.

   * Primary threats include...
     A few tornadoes and a couple intense tornadoes possible
     Widespread large hail and scattered very large hail events to 3
       inches in diameter likely
     Scattered damaging wind gusts to 70 mph possible

   SUMMARY...Supercell thunderstorms will continue to increase in
   coverage and intensity through the afternoon, while posing a threat
   for very large hail, severe/damaging winds, and a few tornadoes.

   The tornado watch area is approximately along and 65 statute miles
   east and west of a line from 45 miles east northeast of Tulsa OK to
   65 miles southwest of Sherman TX. For a complete depiction of the
   watch see the associated watch outline update (WOUS64 KWNS WOU2).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A Tornado Watch means conditions are favorable for
   tornadoes and severe thunderstorms in and close to the watch
   area. Persons in these areas should be on the lookout for
   threatening weather conditions and listen for later statements
   and possible warnings.

   &&

   OTHER WATCH INFORMATION...CONTINUE...WW 40...WW 41...

   AVIATION...Tornadoes and a few severe thunderstorms with hail
   surface and aloft to 3 inches. Extreme turbulence and surface wind
   gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
   storm motion vector 24035.

   ...Gleason/Goss

[Stx_Thunder]

The last time I had a similarly projected (severe) convective/MCS scenario happening around here in Southern TX in mid March (and at night) was back in 2016. Before that, on March 13, 2007. Even though the 2016 one had significant damaging winds in the region, I didn’t lose power. But the 2007 one I did. Though I don’t think the 2016 one had a Cutoff Low involved.

2016 one: https://www.weather.gov/crp/031816_highwind_hail
 

https://www.spc.noaa.gov/exper/archive/event.php?date=20070313

The 2007 one had a non-severe (but restrengthened near coast) MCS, two nights prior and closer to sunrise. Tuesday evening March 13th, discrete supercells popped up around Laredo and Rio Grande plains area then gradually consolidated into a fairly linear but powerful MCS. Propagating east and came right through and off the mid TX coast, fully intact around midnight. I even got to see hail come down which is hard to come by here around the mid-lower TX coast. Very frequent lightning also of course. But there was more of a southwesterly 850mb flow and a thick stratus inversion deck in the low-levels that formed later that evening so I couldn’t see zip lightning out west outside until it got close.

That very following morning behind the MCS on 14th (Wednesday), a few elevated supercells popped up near Victoria and headed toward Houston in the mid day.

[Powerball]

Dry line ia already pretty close to ripping per the visible satellite. There's a nice looking agitated CU field expending down into Big Country.

[Stx_Thunder]

6 hours ago, Quincy said:

12z soundings show an unseasonably unstable air mass already in place (for early day, mid-March standards) with some capping. 

However, guidance erodes capping quite quickly with some model solutions initiating storms prior to midday. 

Wind profiles aren’t ideal, but should be sufficient for initial supercells. Given the background environment, you could see a few intense supercells form. I’d expect complex storm modes/interactions with time, but if a storm can thread the needle, significant severe is certainly a possibility. 

That 12Z Dallas/Fort Worth sounding has wet bulb zero (WBZ) height inside the large hail zone. But Effective shear at 36 Kts is much more meager for supercells than further north in OK at 67.

BRN shear value at 40 is barely in the supercell range also.

[Quincy]

Pretty meh so far across the Oklahoma/Ozarks portion of the threat some. Messy storm modes and somewhat veered low level winds. 

It will be interesting to see if anything goes up near the Red River later as the low-level jet increases. Otherwise the near-term tornado threat in Oklahoma is quite low.