Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 821

May 19, 201134 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 19, 2011, 9:36 PM CDT for 34 counties in Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
May 19, 2011, 9:36 PM CDT (02:36 UTC)
Expired
May 19, 2011, 11:00 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
All 34 counties

Borden County, TX, Briscoe County, TX, Childress County, TX, Coke County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Dawson County, TX, Dickens County, TX, Donley County, TX, Fisher County, TX, Floyd County, TX, Garza County, TX, Glasscock County, TX, Gray County, TX, Hall County, TX, Hemphill County, TX, Howard County, TX, Irion County, TX, Kent County, TX, King County, TX, Lipscomb County, TX, Martin County, TX, Midland County, TX, Mitchell County, TX, Motley County, TX, Nolan County, TX, Reagan County, TX, Roberts County, TX, Scurry County, TX, Sterling County, TX, Stonewall County, TX, Tom Green County, TX, Wheeler County, TX

The radar

The Lubbock radar (KLBB), 119 km from the middle of the area, began a volume at 02:37 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 00:00Z, 2.6 hours before the alert went out and 173 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, Amarillo Airport, TX at 00:00Z on 2011-05-20Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Amarillo Airport, TX at 00:00Z on 2011-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.1939587897Sfc1 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
4539 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

386 
ACUS11 KWNS 200236
SWOMCD
SPC MCD 200236 COR
OKZ000-TXZ000-200400-

MESOSCALE DISCUSSION 0821
NWS STORM PREDICTION CENTER NORMAN OK
0936 PM CDT THU MAY 19 2011

AREAS AFFECTED...ERN TX PANHANDLE...WRN TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 200236Z - 200400Z

CORRECTED FOR WRN TX IN THE HEADER

PORTIONS OF THE ERN TX PANHANDLE AND W TX ARE BEING MONITORED FOR
THUNDERSTORM INITIATION/INCREASING COVERAGE. LARGE HAIL/DAMAGING
WIND GUSTS WILL BE POSSIBLE WITH ANY STORMS TONIGHT. A WW ISSUANCE
MAY BECOME NECESSARY DURING THE NEXT FEW HRS.

WV IMAGERY SHOWS AN UPPER DISTURBANCE MOVING EWD ACROSS SRN
AZ...WITH SIGNS OF INCREASING LARGE SCALE ASCENT BEGINNING TO SPREAD
ACROSS THE SRN HIGH PLAINS. MEANWHILE AT THE SURFACE...DRYLINE HAS
RETREATED WWD INTO PORTIONS OF WRN TX/FAR ERN TX PANHANDLE. ISOLATED
THUNDERSTORMS HAVE BEEN ONGOING ALONG THE DRYLINE SE OF CDS...WHILE
A NEW STORM HAS RECENTLY DEVELOPED WITHIN THE DRIER BOUNDARY LAYER
AIRMASS /WHERE DEWPOINTS ARE IN THE 30S AND 40S/ IMMEDIATELY S OF
LBB /LYNN COUNTY/. THIS NEW DEVELOPMENT LENDS SUPPORT TO SHORT TERM
MODEL GUIDANCE...WHICH SHOWS THUNDERSTORM DEVELOPMENT OCCURRING
ALONG THE MOISTURE/INSTABILITY GRADIENT OVER WRN TX/ERN TX PANHANDLE
BY 05Z. RUC FORECAST SOUNDINGS INDICATE THE PRESENCE OF STEEP
MIDLEVEL LAPSE RATES /7-8 C PER KM IN THE 700-500 MB LAYER/ AND
SURFACE DEWPOINTS IN THE 60S WILL SUPPORT MUCAPE VALUES IN EXCESS OF
1500 J/KG...WITH SHEAR PROFILES FAVORABLE FOR SVR STORMS/POSSIBLE
SUPERCELLS POSING A LARGE HAIL/DAMAGING WIND THREAT. IN
ADDITION...LOW-LEVEL HODOGRAPH STRUCTURE WILL SUPPORT A MARGINAL
TORNADO THREAT DURING THE INITIAL STAGES OF STORM DEVELOPMENT.

..GARNER.. 05/20/2011

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

ATTN...WFO...OUN...SJT...LUB...AMA...MAF...

LAT...LON   35039984 32519991 31220037 31090189 32140218 35810087
            36480046 36419992 35039984

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 19, 7:47 PM CDTMesoscale DiscussionSPCBaylor, Haskell, Knox, Wichita, Wilbarger118 min
May 19, 11:39 PM CDTSevere Thunderstorm WatchSPCBaylor, Borden, Childress, Coke, Cottle, Dickens and 19 more6 hr
May 20, 2:58 AM CDTMesoscale DiscussionSPCBaylor, Coke, Fisher, Foard, Glasscock, Haskell and 11 more92 min
May 20, 10:30 AM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Cherokee, Collin and 31 more60 min
May 20, 11:03 AM CDTTornado WatchSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 10 more7 hr
May 20, 12:08 PM CDTMesoscale DiscussionSPCAnderson, Bandera, Bastrop, Bell, Blanco, Bosque and 56 more67 min
May 20, 12:28 PM CDTSevere Thunderstorm WatchSPCAnderson, Bandera, Bastrop, Bell, Bexar, Blanco and 60 more10 hr
May 20, 1:28 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Franklin, Gregg, Harrison and 8 more62 min
May 20, 4:00 PM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Delta, Franklin and 18 more60 min
May 20, 5:34 PM CDTMesoscale DiscussionSPCAnderson, Bandera, Bastrop, Bell, Bexar, Blanco and 41 more116 min
May 20, 5:56 PM CDTTornado WatchSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 10 more3 hr

Nearby

Mesoscale Discussions in Texas, 2011Every mesoscale discussion in 2011

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.