Severe WX March 17 - 20, 2020 Severe Threat

[Taylor Campbell]

All modes look possible across a wide area next few days.

 

[gangstonc]

If anybody has any time to dissect this a bit, i would love to see it. I’m under a lot of stress right now and having some weather to read about would help.

 

[Bevo]

We currently have a tornado warning in Throckmorton County, far west of Fort Worth. Otherwise, looks like a broken line of storms headed through DFW Metro overnight. Greater threat seems to be tomorrow/Thursday.

 

[Kory]

Nothing looks particularly impressive, but tomorrow and Thursday look like typical spring time thunderstorms with some isolated/scattered severe weather. Tomorrow's problem looks like capping, so a lot of storms will be elevated with hail, but if some cellular convection can become surface based, then a few tornadoes are not out of the question (mainly across West/Central Texas).

I think Thursday's threat will depend on antecedent convection. Lots of morning convection could overturn the atmosphere and create instability issues that may limit severe weather. But shear parameters in place across MO/AR look like they could support a conditional tornado threat if instability materializes.

 

[Kory]

I'm marginally intrigued by Sunday-Tuesday timeframe out this way in AL/TN/MS. A very low amplitude shortwave will be kicking out of the West and may support a smaller threat or multiple out this way during that extended time frame.

 

[patdawg1]

WOUS64 KWNS 180203
WOU3

SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 53
NWS STORM PREDICTION CENTER NORMAN OK
903 PM CDT TUE MAR 17 2020

SEVERE THUNDERSTORM WATCH 53 REMAINS IN EFFECT UNTIL 1200 AM CDT
FOR THE FOLLOWING LOCATIONS

TXC059-081-083-095-103-105-137-151-207-235-253-327-353-371-383-
399-413-417-431-435-441-443-447-451-461-465-180500-
/O.CON.KWNS.SV.A.0053.000000T0000Z-200318T0500Z/

TX
. TEXAS COUNTIES INCLUDED ARE

CALLAHAN COKE COLEMAN
CONCHO CRANE CROCKETT
EDWARDS FISHER HASKELL
IRION JONES MENARD
NOLAN PECOS REAGAN
RUNNELS SCHLEICHER SHACKELFORD
STERLING SUTTON TAYLOR
TERRELL THROCKMORTON TOM GREEN
UPTON VAL VERDE
$$


ATTN...WFO...SJT...MAF...EWX...


Sent from my iPhone using Tapatalk

 

[Bevo]

That big fat Throckmorton county cell is severe-warned and has been floating around for a little over an hour on its journey. 65mph+ winds and quarter-size hail.

 

[Bevo]

Jacksboro cell is dead.Meanwhile, that cell that blew through Graford has been going strong in cycles for a while. Could be yucky if it can tighten its couplet.

 

[Kory]

HRRR has repeatedly taken a supercell across western/northern portions of DFW metroplex this afternoon.

 

[Bevo]

HRRR has repeatedly taken a supercell across western/northern portions of DFW metroplex this afternoon.

Do you think this could be a "if it happens, it's ugly" event similar to what occurred in October? I'm not sure what the capping situation looks like across the Metro right now (if any) but I've been seeing occasional peeks of sunlight this morning.
Supercells really start to pop off SW of Metro in HRRR around 4-5 PM and after.

 

[warneagle]

SPC has introduced a 10% hatched area.

 

[Bevo]

Augh. That's what I was afraid of. Way too close for comfort...

 

[TornadoFan]

Latest HRRR model.

 

[TornadoFan]

Tomorrow has been upgraded to an Enhanced risk with a 10% tornado area as well.

Storm Prediction Center Oct 1, 2024 0600 UTC Day 2 Convective Outlook

Severe weather, tornado, thunderstorm, fire weather, storm report, tornado watch, severe thunderstorm watch, mesoscale discussion, convective outlook products from the Storm Prediction Center.

www.spc.noaa.gov

 

[TornadoFan]

Alot of CAPE in place already.

 

[Bevo]

Do y'all think they'll upgrade the threat level with the next Day 1 in about 10 mins?
New Mesoscale Discussion.

Mesoscale Discussion 0193
NWS Storm Prediction Center Norman OK
0249 PM CDT Wed Mar 18 2020

Areas affected...Parts of the Texas South Plains and Big Country
into the Red River Valley

Concerning...Severe potential...Watch likely

Valid 181949Z - 182145Z

Probability of Watch Issuance...80 percent

SUMMARY...The initiation of discrete thunderstorm development
appears increasingly likely by 6-7 PM CDT, and could commence as
early as 4-5 PM CDT across the Big Country near Abilene, in an
environment increasingly conducive to the formation of supercells.
The primary severe hazards initially are probably large hail and
locally strong surface gusts, but potential for tornadoes could
begin to increase by early evening.

DISCUSSION...Southwesterly mid/upper flow remains broadly
anticyclonic with rising mid-level heights across much of the
region. However, it is and should remain at least weakly difluent,
and model output continues to suggest this may transition at
mid-levels to broadly cyclonic with weak height falls, as a subtle
perturbation overspreads the region by 21-00Z. As this occurs,
there probably will be at least some tempering of increasing
lower/mid tropospheric inhibition, which is ongoing in association
with the northward advection of warmer elevated mixed-layer air.

Daytime heating of a moist boundary layer (surface dew points in the
lower to mid 60s) already appears to be contributing to mixed-layer
CAPE of 1000-2000 J/kg, as winds around 500 mb begin to increase to
40-50 kt. By the time storms initiate, the environment probably
will be conducive to supercells.

Low-level forcing to focus and support thunderstorm initiation
remains a little unclear, but weak low-level warm advection may
contribute to lift. Convection allowing guidance, particularly the
last few runs of the High Resolution Rapid Refresh, suggest
convection may initiate across the Big Country, near Abilene, as
early as 21-22Z.

Low-level hodographs are initially rather modest in size, and may
remain so until after 00-02Z, when near surface wind fields may
begin to back to south/southeasterly, while 850 mb flow begins to
strengthen to 30-40 kt, as the primary upstream short wave begins to
accelerate toward the Southwestern international border area.
However, strongest storms may still pose a risk for large hail,
locally damaging wind gusts and perhaps a brief tornado or two into
early evening.

..Kerr/Dial.. 03/18/2020

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FWD...OUN...SJT...LUB...MAF...

LAT...LON 34320009 34229790 33399738 32459856 30919950 30950086
31770126 34320009

 

[Kory]

I see no need to upgrade.

 

[TornadoFan]

Storms starting to go up south of I-20 and southwest of Abilene

 

[Bevo]

Woop, there it is:

SEL4

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 54
NWS Storm Prediction Center Norman OK
440 PM CDT Wed Mar 18 2020

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of
Southern Oklahoma
West Central Texas

* Effective this Wednesday afternoon from 440 PM until Midnight
CDT.

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

SUMMARY...Scattered intense thunderstorms are expected to develop
this afternoon and spread across the watch area through the evening.
Large hail and damaging winds will occur with the strongest cells.
Through the evening, parameters will become favorable for a few
tornadoes as well.

The tornado watch area is approximately along and 70 statute miles
north and south of a line from 30 miles south of Ardmore OK to 10
miles west southwest of Big Spring TX. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU4).

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.

&&

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 24035.

...Hart

Tarrant/Dallas/Denton county not included, but probably should stay alert.

 

[Kory]

Storm mode went to the crapper real fast today. That put a lid on things.