Alert archive / Oklahoma / Mesoscale Discussions in 2003

Mesoscale Discussion 839

May 8, 200320 counties in Oklahoma; 4 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 8, 2003, 1:57 AM CDT for 20 counties in Oklahoma; 4 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 8, 2003, 1:57 AM CDT (06:57 UTC)
Expired
May 8, 2003, 4:00 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 24 counties

Atoka County, OK, Beckham County, OK, Bryan County, OK, Carter County, OK, Coal County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Jefferson County, OK, Johnston County, OK, Kiowa County, OK, Love County, OK, Marshall County, OK, Murray County, OK, Pontotoc County, OK, Stephens County, OK, Tillman County, OK, Cooke County, TX, Fannin County, TX, Grayson County, TX, Montague County, TX

The radar

The Altus AFB radar (KFDR), 74 km from the middle of the area, began a volume at 06:57 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 watches that followed

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

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 7.0 hours before the alert went out and 125 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, Norman, OK at 00:00Z on 2003-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1026 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, Norman, OK at 00:00Z on 2003-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 123 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
1026 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
1110 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
300 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.9

Open this sounding in Storm Lab

The text

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

863 
ACUS11 KWNS 080657
SWOMCD
SPC MCD 080657 
OKZ000-TXZ000-080900-

MESOSCALE DISCUSSION 0839
NWS STORM PREDICTION CENTER NORMAN OK
0157 AM CDT THU MAY 08 2003

AREAS AFFECTED...SRN OK...PORTIONS N-CENTRAL TX

CONCERNING...TORNADO WATCH 293...

VALID 080657Z - 080900Z

PAIR OF POTENTIALLY TORNADIC SUPERCELLS CONTINUES MOVING EWD ACROSS
S-CENTRAL OK...EXPECTED TO MOVE ACROSS PORTIONS GARVIN/MURRAY/CARTER
COUNTIES THEN HEADED FOR PORTIONS
PONTOTOC/JOHNSTON/MARSHALL/BRYAN/COAL COUNTIES NEXT FEW HOURS.
ADDITIONAL WW MAY BE REQUIRED ACROSS PORTIONS S-CENTRAL/SERN OK NEAR
EXPIRATION TIME OF WW 293 IF CONVECTIVE TRENDS WARRANT.

BECAUSE OF THEIR SIZE...PROFUSE PRECIP PRODUCTION AND CLOSE
PROXIMITY -- 20-25 NM SEPARATION BETWEEN CIRCULATIONS -- NRN STORM
MAY INGEST OUTFLOW OR PRECIP FROM SRN STORM AND WEAKEN...HOWEVER IN
INTERIM WILL MAINTAIN THREAT OF DESTRUCTIVE HAIL AND TORNADOES.

MUCAPE 2500-4000 J/KG INDICATED IN MODIFIED RUC SOUNDINGS OVER
AREA...ALONG WITH 0-3 KM SRH 300-500 J/KG RANGE.  LATTER IS CLOSELY
CORROBORATED BY OBSERVED FWD VWP HODOGRAPH...WHICH SHOWS 50-60 KT
LLJ IMPINGING UPON THIS ACTIVITY.  ALTHOUGH LOW LEVEL AIR MASS
REMAINS VERY MOIST AND SUPPORTIVE OF SEVERE TSTMS...AND DRYLINE
REMAINS W OF REGION...INCREASING CINH OVERNIGHT ACROSS AREA SUGGESTS
PROBABILITIES FOR ADDITIONAL DEVELOPMENT ARE DIMINISHING FROM SW-NE.
 ACCORDINGLY...WW MAY BE CLEARED FROM SW-NE OR W-E AS TRENDS
INDICATE LITTLE POTENTIAL FOR STORM GENESIS.

..EDWARDS.. 05/08/2003

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

ATTN...WFO...FWD...OUN...

34549998 35379995 34669602 33239604 33419708

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 7, 8:01 PM CDTMesoscale DiscussionSPCBeckham, Caddo, Comanche, Cotton, Greer, Harmon and 4 more59 min
May 7, 10:35 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Cherokee, Cleveland and 29 more55 min
May 7, 10:35 PM CDTTornado WatchSPCBeckham, Bryan, Carter, Coal, Comanche, Cotton and 13 more5 hr
May 7, 10:55 PM CDTSevere Thunderstorm WatchSPCAdair, Alfalfa, Beckham, Blaine, Caddo, Canadian and 39 more5 hr
May 7, 11:51 PM CDTMesoscale DiscussionSPCBeckham, Bryan, Carter, Coal, Comanche, Cotton and 13 more54 min
May 8, 1:18 AM CDTMesoscale DiscussionSPCAdair, Blaine, Cherokee, Craig, Custer, Delaware and 19 more3 hr
May 8, 1:55 AM CDTSevere Thunderstorm WatchSPCCraig, Delaware, Grant, Kay, Nowata, Osage and 2 more5 hr
May 8, 3:50 AM CDTSevere Thunderstorm WatchSPCAdair, Atoka, Bryan, Cherokee, Choctaw, Coal and 25 more3 hr
May 8, 3:51 AM CDTMesoscale DiscussionSPCOttawa3 hr
May 8, 5:02 AM CDTMesoscale DiscussionSPCAdair, Atoka, Cherokee, Choctaw, Coal, Creek and 24 more2 hr
May 8, 6:20 AM CDTTornado WatchSPCHaskell, Latimer, LeFlore, Sequoyah3 hr
May 8, 12:49 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Garfield, Grant, Kingfisher, Kiowa and 1 more3 hr
May 8, 1:35 PM CDTTornado WatchSPCAlfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 24 more7 hr
May 8, 3:34 PM CDTMesoscale DiscussionSPCAlfalfa, Caddo, Canadian, Carter, Cleveland, Comanche and 25 more116 min
May 8, 4:47 PM CDTMesoscale DiscussionSPCCanadian, Cleveland, Grady, Lincoln, Logan, McClain and 3 more58 min
May 8, 5:31 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Coal, Craig, Creek, Delaware and 17 more59 min
May 8, 5:45 PM CDTTornado WatchSPCAdair, Cherokee, Coal, Craig, Delaware, Haskell and 17 more5 hr
May 8, 6:38 PM CDTMesoscale DiscussionSPCAdair, Carter, Cherokee, Cleveland, Coal, Craig and 35 more2 hr
May 7, 8:15 PM CDTTornado WatchSPCBosque, Coryell, Ellis, Erath, Freestone, Hamilton and 7 more6 hr
May 8, 2:43 PM CDTMesoscale DiscussionSPCArcher, Bosque, Brown, Burnet, Callahan, Clay and 28 more62 min
May 8, 3:40 PM CDTTornado WatchSPCArcher, Brown, Callahan, Clay, Coleman, Comanche and 18 more5 hr

Nearby

Mesoscale Discussions in Oklahoma, 2003Mesoscale Discussions in Texas, 2003Every mesoscale discussion in 2003

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.