Alert archive / Arkansas / Mesoscale Discussions in 2003

Mesoscale Discussion 2521

November 18, 20034 states

The Storm Prediction Center issued this mesoscale discussion at Nov 18, 2003, 9:55 AM CST for 4 states. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Nov 18, 2003, 9:55 AM CST (15:55 UTC)
Expired
Nov 18, 2003, 11:00 AM CST
In force
65 min
Issued by
the Storm Prediction Center
All 69 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Conway County, AR, Crawford County, AR, Franklin County, AR, Garland County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Montgomery County, AR, Newton County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sevier County, AR, Van Buren County, AR, Washington County, AR, Yell County, AR, Cherokee County, KS, Crawford County, KS, Labette County, KS, Barry County, MO, Barton County, MO, Christian County, MO, Dade County, MO, Douglas County, MO, Greene County, MO, Jasper County, MO, Lawrence County, MO, McDonald County, MO, Newton County, MO, Ozark County, MO, Stone County, MO, Taney County, MO, Adair County, OK, Atoka County, OK, Cherokee County, OK, Choctaw County, OK, Coal County, OK, Craig County, OK, Delaware County, OK, Haskell County, OK, Hughes County, OK, Latimer County, OK, LeFlore County, OK, Mayes County, OK, McCurtain County, OK, McIntosh County, OK, Muskogee County, OK, Nowata County, OK, Okfuskee County, OK, Okmulgee County, OK, Ottawa County, OK, Pittsburg County, OK, Pushmataha County, OK, Rogers County, OK, Sequoyah County, OK, Tulsa County, OK, Wagoner County, OK

The radar

The Western Arkansas radar (KSRX), 63 km from the middle of the area, began a volume at 15:46 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, 3.9 hours before the alert went out and 136 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 2003-11-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 357 joules per kilogram.LCLLFCEL10008507005003002001001 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, Springfield, MO at 12:00Z on 2003-11-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 square meters per square second.1939587897117136Sfc1 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
357 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
576 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

525 
ACUS11 KWNS 181556
SWOMCD
SPC MCD 181555 
ARZ000-MOZ000-OKZ000-KSZ000-TXZ000-181700-

MESOSCALE DISCUSSION 2521
NWS STORM PREDICTION CENTER NORMAN OK
0955 AM CST TUE NOV 18 2003

AREAS AFFECTED...NERN OKM / SERN KS / SWRN MO / WRN AR

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 181555Z - 181700Z

INCREASE IN CONVECTIVE COVERAGE / INTENSITY IS EXPECTED ACROSS THIS
REGION.  NEW WW WILL BE LIKELY BE REQUIRED IN THE NEXT 1 TO 2 HOURS.


CLEARING CONTINUES ACROSS ERN OK / WRN AR ATTM WHERE DEWPOINTS
REMAIN IN THE UPPER 50S AND LOW 60S BEHIND CONVECTIVE LINE.  WITH
DAYTIME HEATING ACROSS THIS REGION BENEATH RAPIDLY COOLING MID-LEVEL
TEMPERATURES...AIRMASS WILL CONTINUE TO DESTABILIZE.  

THUNDERSTORMS ARE QUICKLY DEVELOPING ACROSS NERN OK JUST AHEAD OF
MAIN UPPER TROUGH.  EXPECT STORMS TO INCREASE / MOVE EWD INTO AR AND
SRN MO OVER THE NEXT FEW HOURS.  SUFFICIENT DEEP-LAYER SHEAR FOR
ORGANIZED STORMS COMBINED WITH VERY STEEP LAPSE RATES / COLD
MID-LEVEL TEMPERATURES WILL BE SUPPORTIVE OF LARGE HAIL ACROSS THIS
REGION.  ADDITIONALLY...LOCALLY DAMAGING WINDS MAY BE POSSIBLE WITH
A FEW OF THE STRONGER STORMS.

..GOSS.. 11/18/2003

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

ATTN...WFO...LZK...SGF...SHV...TSA...ICT...FWD...OUN...

37369541 37789422 36989216 34349276 33669377 33999619
35259649

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 17, 7:48 PM CSTMesoscale DiscussionSPCCalhoun, Columbia, Hempstead, Lafayette, Little River, Miller and 3 more87 min
Nov 18, 1:29 AM CSTMesoscale DiscussionSPCArkansas, Clay, Cleveland, Craighead, Crittenden, Cross and 21 more3 hr
Nov 18, 1:55 AM CSTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clay and 34 more6 hr
Nov 18, 10:55 AM CSTSevere Thunderstorm WatchSPCBenton, Calhoun, Clark, Conway, Crawford, Dallas and 24 more5 hr
Nov 18, 1:11 PM CSTMesoscale DiscussionSPCBenton, Clark, Conway, Crawford, Dallas, Franklin and 22 more2 hr
Nov 18, 2:50 PM CSTSevere Thunderstorm WatchSPCArkansas, Ashley, Baxter, Boone, Bradley, Calhoun and 38 more5 hr
Nov 18, 4:44 PM CSTMesoscale DiscussionSPCArkansas, Ashley, Baxter, Boone, Bradley, Calhoun and 34 more2 hr
Nov 18, 7:35 AM CSTMesoscale DiscussionSPCCape Girardeau, Mississippi, Scott115 min

Nearby

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