Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 840

June 2, 202124 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 2, 2021, 4:56 PM CDT for 24 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jun 2, 2021, 4:56 PM CDT (21:56 UTC)
Expired
Jun 2, 2021, 7:30 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 24 counties

Austin County, TX, Bastrop County, TX, Bell County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Fayette County, TX, Grimes County, TX, Harris County, TX, Lampasas County, TX, Lee County, TX, Liberty County, TX, Llano County, TX, Milam County, TX, Mills County, TX, Montgomery County, TX, Robertson County, TX, San Jacinto County, TX, San Saba County, TX, Travis County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 45 km from the middle of the area, began a volume at 21:57 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 9.9 hours before the alert went out and 265 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 12:00Z on 2021-06-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 12:00Z on 2021-06-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
914 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

407 
ACUS11 KWNS 022157
SWOMCD
SPC MCD 022156 
TXZ000-030030-

Mesoscale Discussion 0840
NWS Storm Prediction Center Norman OK
0456 PM CDT Wed Jun 02 2021

Areas affected...central and southeast Texas

Concerning...Severe potential...Watch unlikely 

Valid 022156Z - 030030Z

Probability of Watch Issuance...20 percent

SUMMARY...Storms may increase in coverage along a front from the
Austin area toward Houston. Isolated strong wind gusts or marginal
hail cannot be ruled out.

DISCUSSION...Moderate instability with 2000-2500 J/kg MLCAPE has
developed along and south of a stalled front extending from central
into southeast Texas this afternoon. Winds in the low levels are
weak, but increasing winds aloft in the mid to high levels may
support a few southeastward-moving clusters as storms develop near
the front. Other storms ongoing near San Angelo may also persist
southeastward near the boundary, with marginal wind or hail threat.
Currently, it appears expected severe coverage downstream of watch
233 may not warrant a new watch, but one could be needed should
storms become better organized with any substantial wind threat.

..Jewell/Thompson.. 06/02/2021

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

ATTN...WFO...HGX...FWD...EWX...SJT...

LAT...LON   29769699 30199814 30589890 30929921 31259927 31459904
            31549851 31079639 30639493 30299468 29879477 29599507
            29539548 29769699

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 1, 7:24 PM CDTMesoscale DiscussionSPCAndrews, Borden, Cochran, Crosby, Dawson, Floyd and 11 more96 min
Jun 2, 6:14 AM CDTMesoscale DiscussionSPCArcher, Baylor, Fisher, Haskell, Jones, Knox and 5 more2 hr
Jun 2, 1:28 PM CDTMesoscale DiscussionSPCAndrews, Coke, Concho, Dawson, Ector, Gaines and 11 more2 hr
Jun 2, 2:50 PM CDTSevere Thunderstorm WatchSPCAndrews, Borden, Coke, Concho, Crockett, Dawson and 19 more6 hr

Nearby

Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.