Alert archive / Oklahoma / Mesoscale Discussions in 2003

Mesoscale Discussion 960

May 13, 20037 counties in Arkansas; 9 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 13, 2003, 3:33 PM CDT for 7 counties in Arkansas; 9 counties in Oklahoma. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: May 13, 2003, 3:33 PM CDT (20:33 UTC)
Expired: May 13, 2003, 5:00 PM CDT
In force: 87 min
Issued by: the Storm Prediction Center

Counties Crawford County, AR, Franklin County, AR, Logan County, AR, Madison County, AR, Scott County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Cherokee County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, McIntosh County, OK, Muskogee County, OK, Sequoyah County, OK, Wagoner County, OK

The radar

The Western Arkansas radar (KSRX), 37 km from the middle of the area, began a volume at 20:35 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

Springfield, MO (KSGF), launched 12:00Z, 8.6 hours before the alert went out and 208 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1853 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 168 m²/s²
0-3 km storm-relative helicity: 173 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.

000 
ACUS11 KWNS 132034
SWOMCD
SPC MCD 132033 
ARZ000-OKZ000-132200-

MESOSCALE DISCUSSION 0960
NWS STORM PREDICTION CENTER NORMAN OK
0333 PM CDT TUE MAY 13 2003

AREAS AFFECTED...ERN/NERN OK...WRN/NWRN AR

CONCERNING...SEVERE THUNDERSTORM WATCH 361...

VALID 132033Z - 132200Z

A SCATTERED LINE OF CONVECTION CONTINUES TO AFFECT PORTIONS OF WW
#361 IN ERN/NERN OK INTO WRN/NWRN AR. WW EXPECTED TO REMAIN IN
EFFECT THRU EXPIRATION WITH AN ADDITIONAL ISSUANCE FURTHER SOUTH A
POSSIBILITY.

RADAR/SATELLITE IMAGERY INDICATES CONVECTION CONTINUES TO MOVE SSE
/320 DEGREES/ AT AROUND 25 KT INTO ERN OK...WRN/WCNTRL ARK. RECENT
SURFACE MESOANALYSIS SHOWS THE AIRMASS IN THESE AREAS IS RATHER
STABLE WITH TEMPERATURES IN THE MID-UPPER 70S AND DEWPOINT VALUES
FROM THE UPPER 50S INTO THE MID 60S. THIS TEMPERATURE-DEWPT.
COMBINATION YIELDS 100MB MIXED CAPES FROM 250-1000 J/KG IN THESE
AREAS WITH THE HIGHER INSTABILITY VALUES IN ECNTRL OK. MOST RECENT
SURFACE OBJECTIVE ANALYSIS FIELDS INDICATES WEAKEN CIN VALUES FROM
AN OKMULGEE-PITTSBURGH COUNTY LINE WHERE DEWPOINTS HAVE CREPT BACK
INTO THE UPPER 60S HELPING 100MB MIXED CAPES TO RISE TO BETWEEN
1000-1500 J/KG.

EXPECT ERN PORTIONS OF CONVECTIVE SEGMENT TO GRADUALLY WEAKEN AS IT
APPROACHES A MORE STABLE BOUNDARY LAYER REGIME IN CNTRL/WCNTRL
AR...WHILE FURTHER WEST...INTO ECNTRL OK CONVECTION SHOULD REMAIN
STRONG FOR THE NEXT SEVERAL HOURS. RECENT MESONET REPORTS INDICATE
WIND GUSTS TO BETWEEN 35-45 KTS AMIDST THE RELATIVELY STABLE REGIME
IN ERN OK...SO CONVECTION HAS BEEN STRONG ENOUGH TO MIX STRONGER
WINDS DOWN TO THE SURFACE AND EXPECT THIS TREND TO CONTINUE AS
CONVECTION MOVES MORE SWD INTO HASKELL/SEQYOYAH/MUSKOGEE/AND
MCINTOSH COUNTIES.

..NADEN.. 05/13/2003

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

ATTN...WFO...LZK...TSA...

34459384 34719550 35209590 36299586 36089356

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 13, 10:08 AM CDT	Mesoscale Discussion	SPC	Benton	97 min
May 13, 1:18 PM CDT	Mesoscale Discussion	SPC	Benton, Crawford, Franklin, Johnson, Logan, Madison and 6 more	87 min
May 13, 2:20 PM CDT	Severe Thunderstorm Watch	SPC	Crawford, Franklin, Logan, Madison, Montgomery, Scott and 2 more	6 hr
May 13, 5:45 PM CDT	Severe Thunderstorm Watch	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 22 more	4 hr
May 13, 6:18 PM CDT	Mesoscale Discussion	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 26 more	87 min
May 13, 5:50 AM CDT	Mesoscale Discussion	SPC	Atoka, Bryan, Choctaw, Cleveland, Coal, Garvin and 7 more	3 hr
May 13, 1:53 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Blaine, Canadian, Cleveland, Creek, Garfield and 12 more	97 min
May 13, 5:04 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Beckham, Blaine, Caddo, Custer, Dewey and 11 more	86 min

Nearby

Mesoscale Discussions in Oklahoma, 2003 Mesoscale Discussions in Arkansas, 2003 Every 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.