Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 430

April 21, 20166 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2016, 4:57 AM CDT for 6 counties in Texas. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued: Apr 21, 2016, 4:57 AM CDT (09:57 UTC)
Expired: Apr 21, 2016, 6:30 AM CDT
In force: 93 min
Issued by: the Storm Prediction Center

Counties Coke County, TX, Coleman County, TX, Concho County, TX, Runnels County, TX, Taylor County, TX, Tom Green County, TX

The radar

The San Angelo radar (KSJT), 65 km from the middle of the area, began a volume at 09:59 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

Midland Regional, TX (KMAF), launched 00:00Z, 10.0 hours before the alert went out and 209 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2940 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: -1 m²/s²
0-3 km storm-relative helicity: 97 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

999 
ACUS11 KWNS 210958
SWOMCD
SPC MCD 210957 
TXZ000-211130-

MESOSCALE DISCUSSION 0430
NWS STORM PREDICTION CENTER NORMAN OK
0457 AM CDT THU APR 21 2016

AREAS AFFECTED...PORTIONS OF CENTRAL TX

CONCERNING...SEVERE THUNDERSTORM WATCH 100...

VALID 210957Z - 211130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 100
CONTINUES.

SUMMARY...ISOLATED HAIL AND GUSTY WINDS MAY PERSIST ANOTHER HOUR OR
TWO ACROSS PORTIONS OF WEST-CENTRAL TX. A NEW WATCH IS NOT EXPECTED
AT THIS TIME DOWNSTREAM OF WW 100.

DISCUSSION...EARLIER LINE OF MARGINAL TO SEVERE THUNDERSTORMS HAS
DIMINISHED EXCEPT FOR A BOWING SEGMENT MOVING INTO RUNNELS COUNTY IN
WEST-CENTRAL TX. THIS CONVECTION IS MOVING INTO AN AREA WHERE
OUTFLOW FROM EARLIER STORMS HAS LIKELY FURTHER STABILIZED LOW LEVELS
AND RESULTED IN NORTH TO EASTERLY LOW LEVEL WINDS.
FURTHERMORE...LATEST RADAR DATA SUGGESTS OUTFLOW FROM THE CURRENT
BOW IS STARTING TO SURGE EAST/SOUTHEASTWARD. MRMS MESH CONTINUES TO
INDICATE AT LEAST MARGINALLY SEVERE HAIL IS STILL POSSIBLE. STEEP
LAPSE RATES ARE PRESENT...BUT DEEP LAYER SHEAR WEAKENS WITH EASTWARD
EXTENT...WHERE INHIBITION ALSO INCREASES. AS SUCH...A WEAKENING
TREND IS EXPECTED. WHILE A MARGINAL SEVERE THREAT MAY PERSIST
ANOTHER HOUR OR TWO...A NEW WATCH IS NOT EXPECTED AT THIS TIME
DOWNSTREAM OF SEVERE THUNDERSTORM WATCH 100.

..LEITMAN.. 04/21/2016

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

ATTN...WFO...SJT...

LAT...LON   32009926 31739918 31499924 31319944 31289972 31300031
            31370076 31550094 31830095 32040058 32260041 32410021
            32379972 32009926

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, 9:40 AM CDT	Mesoscale Discussion	SPC	Brazoria, Chambers, Hardin, Liberty, Tyler	2 hr
Apr 21, 2:14 PM CDT	Mesoscale Discussion	SPC	Cameron, Hidalgo, Kenedy, Willacy	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.