Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 433

April 21, 20164 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2016, 2:14 PM CDT for 4 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 21, 2016, 2:14 PM CDT (19:14 UTC)
Expired: Apr 21, 2016, 4:15 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Cameron County, TX, Hidalgo County, TX, Kenedy County, TX, Willacy County, TX

The radar

The Brownsville radar (KBRO), 90 km from the middle of the area, began a volume at 19:16 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

Brownsville Intl, TX (KBRO), launched 12:00Z, 7.2 hours before the alert went out and 92 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1909 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 565 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: -22 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

061 
ACUS11 KWNS 211914
SWOMCD
SPC MCD 211914 
TXZ000-212115-

MESOSCALE DISCUSSION 0433
NWS STORM PREDICTION CENTER NORMAN OK
0214 PM CDT THU APR 21 2016

AREAS AFFECTED...DEEP SOUTH TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 211914Z - 212115Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ADDITIONAL STORMS ARE EXPECTED TO DEVELOP OVER A PORTION
OF DEEP SOUTH TEXAS THIS AFTERNOON INTO EARLY EVENING AND POSE A
MODEST THREAT FOR LOCALLY STRONG WIND GUSTS AND MARGINALLY SEVERE
HAIL. A WW IS NOT ANTICIPATED.

DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS A CONVECTIVE OUTFLOW
BOUNDARY FROM NEAR KINGSVILLE TO LAREDO MOVING SWD. THE SEABREEZE
HAS MOVED INLAND AND IS LOCATED FROM NEAR BROWNSVILLE TO JUST WEST
OF CORPUS CHRISTI WHERE AN ISOLATED STORM WITH MARGINAL SUPERCELL
STRUCTURES HAS DEVELOPED AND IS MOVING SWD ALONG THE BOUNDARY.
ADDITIONAL STORMS ARE LIKELY...PARTICULARLY WHERE CONVERGENCE IS
MAXIMIZED AS THE OUTFLOW BOUNDARY INTERSECTS THE SEABREEZE.
OBJECTIVE ANALYSIS INDICATES THE ATMOSPHERE TO BE MODERATELY
UNSTABLE WITH STEEP MID-LEVEL LAPSE RATES. ISOLATED DOWNBURST WINDS
AND SOME HAIL WILL REMAIN POSSIBLE AS STORMS DEVELOP IN THIS
ENVIRONMENT THIS AFTERNOON.

..DIAL/GUYER.. 04/21/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...BRO...

LAT...LON   27199761 26429739 25959732 26089791 26279822 26869848
            27109808 27199761

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 20, 8:17 PM CDT	Severe Thunderstorm Watch	SPC	Armstrong, Baylor, Briscoe, Carson, Childress, Collingsworth and 23 more	6 hr
Apr 20, 8:22 PM CDT	Mesoscale Discussion	SPC	Duval, Jim Hogg, Starr, Webb, Zapata	83 min
Apr 20, 9:40 PM CDT	Mesoscale Discussion	SPC	Cottle, Crosby, Dickens, Fisher, Foard, Garza and 7 more	65 min
Apr 20, 11:35 PM CDT	Mesoscale Discussion	SPC	Crosby, Fisher, Garza, Haskell, Jones, Kent and 5 more	55 min
Apr 21, 1:16 AM CDT	Mesoscale Discussion	SPC	Borden, Callahan, Coke, Coleman, Dawson, Fisher and 19 more	89 min
Apr 21, 1:44 AM CDT	Severe Thunderstorm Watch	SPC	Borden, Coke, Dawson, Gaines, Glasscock, Howard and 7 more	4 hr
Apr 21, 4:57 AM CDT	Mesoscale Discussion	SPC	Coke, Coleman, Concho, Runnels, Taylor, Tom Green	93 min
Apr 21, 9:40 AM CDT	Mesoscale Discussion	SPC	Brazoria, Chambers, Hardin, Liberty, Tyler	2 hr
Apr 21, 2:36 PM CDT	Mesoscale Discussion	SPC	Brewster, Crockett, Edwards, Pecos, Terrell, Val Verde	2 hr

Nearby

Mesoscale Discussions in Texas, 2016 Every mesoscale discussion in 2016

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.