Alert archive / Texas / Mesoscale Discussions in 2008

Mesoscale Discussion 813

May 7, 200813 counties in Oklahoma; 41 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 7, 2008, 3:13 PM CDT for 13 counties in Oklahoma; 41 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 7, 2008, 3:13 PM CDT (20:13 UTC)
Expired
May 7, 2008, 5:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 54 counties

Atoka County, OK, Bryan County, OK, Carter County, OK, Choctaw County, OK, Coal County, OK, Garvin County, OK, Hughes County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, Murray County, OK, Pontotoc County, OK, Pushmataha County, OK, Anderson County, TX, Bastrop County, TX, Bell County, TX, Bosque County, TX, Collin County, TX, Cooke County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Ellis County, TX, Falls County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Grayson County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, McLennan County, TX, Milam County, TX, Montague County, TX, Navarro County, TX, Rains County, TX, Robertson County, TX, Rockwall County, TX, Smith County, TX, Tarrant County, TX, Travis County, TX, Van Zandt County, TX, Williamson County, TX, Wise County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 49 km from the middle of the area, began a volume at 20:17 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

Fort Worth, TX (KFWD), launched 12:00Z, 8.2 hours before the alert went out and 50 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 2008-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 72 joules per kilogram.LCLLFCEL10008507005003002001001 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 2008-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 196 square meters per square second.1939587897117Sfc1 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
72 J/kg
Mixed-layer CIN
-374 J/kg
Mixed-layer LCL
627 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
196 m²/s²
0-3 km storm-relative helicity
398 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 072013
SWOMCD
SPC MCD 072013 
TXZ000-OKZ000-072215-

MESOSCALE DISCUSSION 0813
NWS STORM PREDICTION CENTER NORMAN OK
0313 PM CDT WED MAY 07 2008

AREAS AFFECTED...PARTS OF CNTRL/NE TX INTO S CNTRL/ERN OK

CONCERNING...TORNADO WATCH 273...

VALID 072013Z - 072215Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 273 CONTINUES.

ADDITIONAL WW/S/ WILL PROBABLY BE NEEDED EAST/SOUTH OF WW 273 LATE
THIS AFTERNOON.

AS COLD MID-LEVEL CLOSED LOW CONTINUES TO DEVELOP EASTWARD ACROSS
THE TEXAS PANHANDLE REGION...ASSOCIATED SURFACE LOW IS NOW MIGRATING
INTO SOUTH CENTRAL OKLAHOMA.  TO THE SOUTH OF THE SURFACE
LOW...BENEATH SUBSIDENT DRY SLOT TO THE SOUTH/EAST OF THE MID/UPPER
CIRCULATION...THE DRY LINE IS IN THE PROCESS OF SLOWLY SHARPENING
...AND LIKELY WILL EXTEND NORTHEAST OF ARDMORE THROUGH AREAS NEAR/
EAST OF THE DALLAS/FORT WORTH METROPLEX INTO THE WACO/AUSTIN
VICINITY BY 23Z.  LOW-LEVEL WARM ADVECTION ALONG AND EAST OF THIS
FEATURE...IN CONJUNCTION WITH ADDITIONAL HEATING...SEEMS LIKELY TO
BECOME SUPPORTIVE OF INCREASING DISCRETE CONVECTIVE DEVELOPMENT. 
ACTIVITY APPEARS POSSIBLE AS FAR EAST AS A LOW-LEVEL CONFLUENT ZONE
NEAR THE 40 KT SOUTHERLY LOW-LEVEL JET AXIS EXTENDING NORTHWEST OF
HOUSTON INTO AREAS WEST OF THE ARKLATEX.

THOUGH MIXED LAYER CAPE IS EXPECTED TO SOMEWHAT MODEST...AROUND 1000
J/KG...STRONG DEEP LAYER SHEAR BENEATH A BROADLY CYCLONIC... 70-80
KT SOUTHWESTERLY 500 MB JET STREAK PROGRESSING ACROSS THE SOUTHERN
PLAINS SHOULD BE SUFFICIENT FOR SUPERCELLS.  AND...LOW- LEVEL
HODOGRAPHS APPEAR LIKELY TO REMAIN STRONG ENOUGH TO SUPPORT A RISK
FOR TORNADOES...IN ADDITION TO LARGE HAIL AND LOCALLY DAMAGING WIND
GUSTS.

..KERR.. 05/07/2008

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

ATTN...WFO...SHV...TSA...HGX...FWD...OUN...EWX...

33329787 34119769 34789727 35229605 34459537 33509509
32389522 31299588 30589652 29919746 29899837 31909770

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 6, 8:50 PM CDTMesoscale DiscussionSPCBeckham, Custer, Ellis, Greer, Harmon, Jackson and 4 more85 min
May 6, 9:51 PM CDTSevere Thunderstorm WatchSPCBeaver, Cimarron, Harmon, Jackson, Texas, Tillman7 hr
May 6, 9:59 PM CDTMesoscale DiscussionSPCWoods61 min
May 7, 12:04 AM CDTMesoscale DiscussionSPCBeaver, Beckham, Custer, Ellis, Greer, Harmon and 5 more86 min
May 7, 2:47 AM CDTMesoscale DiscussionSPCBeckham, Caddo, Comanche, Cotton, Custer, Greer and 5 more58 min
May 7, 7:07 AM CDTMesoscale DiscussionSPCAtoka, Carter, Cherokee, Cleveland, Coal, Creek and 25 more53 min
May 7, 7:33 AM CDTSevere Thunderstorm WatchSPCAdair, Cherokee, Delaware, Haskell, Latimer, LeFlore and 9 more5 hr
May 7, 9:52 AM CDTMesoscale DiscussionSPCAdair, Cherokee, Cleveland, Coal, Craig, Creek and 22 more83 min
May 7, 1:33 PM CDTTornado WatchSPCAtoka, Bryan, Carter, Cleveland, Coal, Cotton and 14 more6 hr
May 7, 4:47 PM CDTMesoscale DiscussionSPCHaskell, Latimer, LeFlore, McCurtain, Pushmataha88 min
May 7, 5:28 PM CDTTornado WatchSPCAdair, Cherokee, Choctaw, Craig, Creek, Delaware and 20 more8 hr
May 7, 6:35 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Choctaw, Coal, Johnston, Marshall55 min
May 6, 11:35 PM CDTMesoscale DiscussionSPCBandera, Edwards, Gillespie, Kerr, Kinney, Maverick and 4 more85 min
May 7, 11:59 AM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Callahan, Cottle, Crosby and 29 more91 min
May 7, 1:17 PM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Callahan, Cottle, Crosby and 29 more88 min
May 7, 3:42 PM CDTTornado WatchSPCAnderson, Bell, Ellis, Falls, Freestone, Henderson and 9 more6 hr

Nearby

Mesoscale Discussions in Texas, 2008Mesoscale Discussions in Oklahoma, 2008Every mesoscale discussion in 2008

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.