Mesoscale Discussion 2179

Issued

Dec 19, 2012, 7:07 PM CST (01:07 UTC)

Expired

Dec 19, 2012, 8:00 PM CST

In force

53 min

Issued by

the Storm Prediction Center

Chance of a watch

95%

The Western Arkansas radar (KSRX), 70 km from the middle of the area, began a volume at 01:07 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.

• Tornado Watch 686Dec 19, 7:35 PM CST
• Severe Thunderstorm Watch 687Dec 19, 9:55 PM CST

024 
ACUS11 KWNS 200107
SWOMCD
SPC MCD 200107 
ARZ000-MOZ000-TXZ000-OKZ000-KSZ000-200200-

MESOSCALE DISCUSSION 2179
NWS STORM PREDICTION CENTER NORMAN OK
0707 PM CST WED DEC 19 2012

AREAS AFFECTED...EASTERN OK/NORTHEAST TX/WESTERN AR/FAR SOUTHEAST
KS/SOUTHWEST MO

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 

VALID 200107Z - 200200Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SEVERE TSTM POTENTIAL IS LIKELY TO QUICKLY INCREASE THIS
EVENING ACROSS PORTIONS OF EASTERN OK/NORTHEAST TX INTO WESTERN AR
ALONG WITH ADJACENT PARTS OF EXTREME SOUTHEAST KS/SOUTHWEST MO. A
TORNADO WATCH WILL LIKELY BE NECESSARY FOR AT LEAST PORTIONS OF THIS
REGION WITHIN THE HOUR /LIKELY BY 02Z/.

DISCUSSION...00Z SURFACE ANALYSIS IS INDICATIVE OF A 996 MB SURFACE
LOW NEAR THE I-35 CORRIDOR OF NORTH-CENTRAL OK/SOUTH-CENTRAL
KS...WITH A STATIONARY FRONT OR SLOW-MOVING MOVING WARM FRONT
EXTENDING EASTWARD ACROSS FAR SOUTHEAST MO...IN ADDITION TO A
SOUTHEASTWARD-MOVING COLD FRONT AND A PRECEDING DRY LINE ACROSS
OK/NORTH-CENTRAL TX. THE ARRIVAL OF CONSEQUENTIAL DPVA/MASS RESPONSE
ASSOCIATED WITH A PLAINS UPPER TROUGH WILL LIKELY CONTRIBUTE TO
INCREASING CONVECTIVE DEVELOPMENT BY THE MID/LATE EVENING
HOURS...ALTHOUGH A RECENT CONVECTIVE INCREASE HAS ALREADY BEEN NOTED
IN LATIMER COUNTY OK PER RADAR IMAGERY AS OF 0115Z...AND MORE
ROBUSTLY IN VICINITY OF A PRE-FRONTAL TROUGH/DRYLINE NEAR THE RED
RIVER OF SOUTH-CENTRAL OK/NORTH-CENTRAL TX.

THE 00Z FORT WORTH OBSERVED SOUNDING WAS INDICATIVE OF RELATIVELY
LITTLE CINH...WITH A RELATIVELY STEEP LAPSE RATES PROFILE AND MLCAPE
AROUND 300 J/KG. SPC OBJECTIVE ANALYSIS OTHERWISE SUGGESTS THAT
LOW-LEVEL CINH EROSION CONTINUES TO OCCUR WITHIN THE WARM SECTOR
WHERE UPPER 50S/LOWER 60S F SURFACE DEWPOINTS ARE INCREASINGLY
PREVALENT.  

WITH A PROBABLE INCREASE /QUICK AT THAT/ IN STORM COVERAGE AND
INTENSITY BY MID-EVENING...VERY STRONG DEEP LAYER SOUTHWESTERLY
WINDS ABOVE THE SURFACE AND RESULTANT 70+ KT 0-6 KM SHEAR WILL
SUPPORT A MIXED-MODE OF SUPERCELLS AND THE EVOLUTION OF
SMALL/FAST-NORTHEASTWARD MOVING LINEAR SEGMENTS TONIGHT...WHICH IS
GENERALLY CONSISTENT BY VARIOUS HIGH-RES CONVECTION-ALLOWING
GUIDANCE. WHILE SEVERE HAIL WILL BE POSSIBLE WITHIN THE FIRST FEW
HOURS OF CONVECTIVE INITIATION...DAMAGING WINDS AND THE POSSIBILITY
OF A FEW TORNADOES SHOULD BE THE MORE PREVALENT RISKS.

..GUYER/WEISS.. 12/20/2012

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

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

LAT...LON   36699630 37519556 37699444 37839262 37319172 36009193
            33109389 32179713 33699677 36699630

Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Missouri, 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.