Alert archive / Arkansas / Mesoscale Discussions in 2003

Mesoscale Discussion 957

May 13, 200312 counties in Arkansas; 8 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at May 13, 2003, 1:18 PM CDT for 12 counties in Arkansas; 8 counties in Oklahoma. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
May 13, 2003, 1:18 PM CDT (18:18 UTC)
Expired
May 13, 2003, 2:45 PM CDT
In force
87 min
Issued by
the Storm Prediction Center

Counties Benton County, AR, Crawford County, AR, Franklin County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Newton County, AR, Pope County, AR, Scott County, AR, Sebastian County, AR, Washington County, AR, Yell County, AR, Adair County, OK, Cherokee County, OK, Delaware County, OK, Haskell County, OK, LeFlore County, OK, Mayes County, OK, Muskogee County, OK, Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 38 km from the middle of the area, began a volume at 18:22 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

Springfield, MO (KSGF), launched 12:00Z, 6.3 hours before the alert went out and 154 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, Springfield, MO at 12:00Z on 2003-05-13Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 12:00Z on 2003-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 168 square meters per square second.19395878Sfc1 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
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.

431 
ACUS11 KWNS 131818
SWOMCD
SPC MCD 131818 
ARZ000-MOZ000-OKZ000-131945-

MESOSCALE DISCUSSION 0957
NWS STORM PREDICTION CENTER NORMAN OK
0118 PM CDT TUE MAY 13 2003

AREAS AFFECTED...NERN OK / NWRN AR

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 131818Z - 131945Z

RECENT SATELLITE/RADAR IMAGERY SUGGESTS CONVECTIVE COMPLEX HAS BEGUN
TO CHANGE CHARACTER OVER THE PAST HOUR. IT APPEARS AN INCREASING
WIND DAMAGE THREAT COULD BE DEVELOPING.  WW MAY BE NEEDED SHORTLY.

RECENT RADAR IMAGERY INDICATES ACTIVITY IN NERN OK/NWRN AR CONTINUES
TO BECOME MORE LINEAR WITH A WARM ADVECTIVE WING POKING INTO NWRN
AR/SWRN MO. THE MOST RECENT SURFACE ANALYSIS SHOWS A NONDESCRIPT
WARM FRONTAL BOUNDARY FROM NRN TX NWD THRU CNTRL OK WITH THE AREA OF
CONCERN ONLY WEAKLY UNSTABLE AT THE SURFACE WITH LESS THAN 500 J/KG
OF 50MB MIXED CAPE VALUES. HOWEVER...THE PRESENT CONVECTIVE COMPLEX
IS ABOVE THE BOUNDARY LAYER WITH TEMPERATURES FROM THE MID 60S INTO
THE LOW 70S AND DEWPOINTS FROM THE UPPER 50S INTO THE LOW 60S. SOME
BACKBUILDING IS POSSIBLE WITH INCREASING SWLY LOW-LVL INFLOW INTO
NCNTRL/ECNTRL OK...BUT THE AREA WITH THE MAIN WIND THREAT APPEARS TO
BE MOST LIKELY FROM NERN OK INTO EXTREME NWRN AR OVER THE NEXT HOUR. 

..NADEN.. 05/13/2003

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

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

34829320 34639394 34729469 35509564 36669523 36639443
36259336 35759290

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 13, 10:08 AM CDTMesoscale DiscussionSPCBenton97 min
May 13, 2:20 PM CDTSevere Thunderstorm WatchSPCCrawford, Franklin, Logan, Madison, Montgomery, Scott and 2 more6 hr
May 13, 3:33 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Logan, Madison, Scott, Sebastian and 1 more87 min
May 13, 5:45 PM CDTSevere Thunderstorm WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 22 more4 hr
May 13, 6:18 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 26 more87 min
May 13, 5:50 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Choctaw, Cleveland, Coal, Garvin and 7 more3 hr
May 13, 1:53 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Canadian, Cleveland, Creek, Garfield and 12 more97 min
May 13, 5:04 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Custer, Dewey and 11 more86 min

Nearby

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