Mesoscale Discussion 1990

Issued

Sep 26, 2012, 1:26 PM CDT (18:26 UTC)

Expired

Sep 26, 2012, 3:00 PM CDT

In force

94 min

Issued by

the Storm Prediction Center

Chance of a watch

40%

The Paducah radar (KPAH), 178 km from the middle of the area, began a volume at 18:28 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.

286 
ACUS11 KWNS 261826
SWOMCD
SPC MCD 261826 
KYZ000-INZ000-ILZ000-TNZ000-MOZ000-ARZ000-262000-

MESOSCALE DISCUSSION 1990
NWS STORM PREDICTION CENTER NORMAN OK
0126 PM CDT WED SEP 26 2012

AREAS AFFECTED...SOUTHERN MO/NORTHERN AR INTO NORTHWEST TN/WESTERN
KY/SOUTHERN IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 261826Z - 262000Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTMS ARE EXPECTED TO CONTINUE TO INCREASE ACROSS SOUTHERN
MO/NORTHERN AR INTO SOUTHERN IL/WESTERN KY/NORTHWEST TN THROUGH
MID/LATE AFTERNOON...WITH THE STRONGEST TSTMS CAPABLE OF DAMAGING
WINDS/SEVERE HAIL. WHILE A WATCH IS NOT
IMMINENT/CERTAIN...DEVELOPMENTAL TRENDS WILL BE MONITORED FOR A
POSSIBLE SEVERE TSTM WATCH.

DISCUSSION...AHEAD OF A CLUSTER OF SHOWERS/FEW TSTMS ACROSS
NORTHEAST OK/FAR SOUTHWEST MO AS OF MIDDAY...STRONGER CELLULAR
CONVECTION HAS RECENTLY /SINCE 1730Z/ INCREASED ACROSS FAR SOUTHERN
MO/NORTHWEST AR/FAR NORTHEAST OK. THIS APPEARS TO BE OCCURRING IN
VICINITY OF A REMNANT EARLY DAY OUTFLOW BOUNDARY ACROSS SOUTHERN MO.
HEATING/DESTABILIZING AIRMASS ASIDE...THIS DEVELOPMENT APPEARS TO BE
FURTHER AIDED BY AN EASTWARD-MOVING SHORTWAVE TROUGH/POSSIBLE MCV
ACROSS SOUTHEAST KS/NORTHEAST OK. WHILE EXISTING CLOUD COVER
/ESPECIALLY ACROSS SOUTHERN MO/ WILL BE AT LEAST SOMEWHAT HINDER THE
DEGREE OF HEATING AND DESTABILIZATION...DEVELOPMENT OF 1000-2000
J/KG MLCAPE WILL ACCOUNT FOR SOME STRONGER/SUSTAINED UPDRAFTS THIS
AFTERNOON.

THIS IS ESPECIALLY THE CASE GIVEN THAT SOMEWHAT ENHANCED MID
TROPOSPHERIC FLOW...LIKELY ASSOCIATED WITH THE AFOREMENTIONED
MID-LEVEL IMPULSE...WILL SPREAD EASTWARD ACROSS THE REGION. RECENT
WSR-88D VWP DATA FROM TULSA WSR-88D IS INDICATIVE OF 40+ 0-6 KM
SHEAR. THIS MAY PROVE SUFFICIENT FOR SOME SEMI-ORGANIZED STRUCTURES
INCLUDING SOME MARGINAL SUPERCELL STRUCTURES...AND EVENTUALLY SMALL
BOWING SEGMENTS AS UPSCALE GROWTH MAY GRADUALLY OCCUR. WHILE THE
OVERALL SCOPE OF THE SEVERE THREAT IS A BIT UNCERTAIN IN THE SHORT
TERM...DAMAGING WINDS/SEVERE HAIL WILL BE POSSIBLE AT LEAST ON AN
ISOLATED BASIS THIS AFTERNOON.

..GUYER/MEAD.. 09/26/2012

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

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA...

LAT...LON   37279215 37579058 38138833 37778765 36468847 35609012
            35299427 36709312 37279215

Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Missouri, 2012Mesoscale Discussions in Illinois, 2012Every mesoscale discussion in 2012

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.