Mesoscale Discussion 2182

Issued

Dec 19, 2012, 10:22 PM CST (04:22 UTC)

Expired

Dec 19, 2012, 11:45 PM CST

In force

83 min

Issued by

the Storm Prediction Center

The Western Arkansas radar (KSRX), 102 km from the middle of the area, began a volume at 04:22 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.

316 
ACUS11 KWNS 200423
SWOMCD
SPC MCD 200422
MOZ000-ARZ000-TXZ000-OKZ000-200545-

MESOSCALE DISCUSSION 2182
NWS STORM PREDICTION CENTER NORMAN OK
1022 PM CST WED DEC 19 2012

AREAS AFFECTED...FAR EASTERN OK/EXTREME SOUTHEAST KS/NORTHEAST TX TO
WESTERN AR/SOUTHERN MO

CONCERNING...TORNADO WATCH 686...

VALID 200422Z - 200545Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 686 CONTINUES.

SUMMARY...DAMAGING WIND/ISOLATED TORNADO POTENTIAL CONTINUES WITHIN
TORNADO WATCH 686...ESPECIALLY A CORRIDOR FROM NORTHEAST
TX/SOUTHEAST OK INTO NORTHWEST AR/SOUTHWEST MO. ADDITIONAL PARTS OF
CENTRAL/NORTHERN AR AND SOUTH-CENTRAL MO WILL BE MONITORED THROUGH
LATE EVENING/OVERNIGHT FOR A NEED OF AREAL WATCH EXPANSION AND/OR AN
ADDITIONAL WATCH...ALTHOUGH SUCH A NEED IS NOT CERTAIN.

DISCUSSION...AS OF 04Z...A NEARLY CONTINUOUS BAND OF STRONG TO
SEVERE TSTMS CONTINUES TO CONSOLIDATE AND SPREAD EAST-NORTHEASTWARD
WITHIN A CORRIDOR FROM NORTHEAST TX/SOUTHEAST OK INTO NORTHWEST
AR/SOUTHWEST MO...WITH A SURFACE COLD POOL GRADUALLY BECOMING MORE
APPARENT ACROSS EXTREME EAST-CENTRAL/SOUTHEAST OK. A 55 KT WIND GUST
WAS RECENTLY /329Z/ MEASURED AT FORT SMITH AR. LINE-LEADING
SEMI-DISCRETE STORMS /SOME WITH PERIODIC ROTATION/ HAVE ALSO BEEN
COMMON IN WEST-CENTRAL/NORTHWEST AR AND SOUTHERN MO.

ACCENTUATED BY THE DEEPENING PHASE OF THE CYCLONE
TONIGHT...INCREASING DEEP LAYER FORCING FOR ASCENT AND A HIGHLY
SHEARED ENVIRONMENT WILL PROMOTE THE SUSTENANCE OF A FORCED
LINE/QLCS ACROSS SOUTHERN MO/MUCH OF AR TO THE ADJACENT
ARKLATEX...EVEN WITH MINIMAL BUOYANCY /AS LOW AS A FEW HUNDRED J PER
KG SBCAPE/. DAMAGING WINDS WILL REMAIN POSSIBLE INTO THE
OVERNIGHT...ALONG WITH THE POTENTIAL FOR A FEW TORNADOES WITH ANY
EMBEDDED MESO-VORTICES/SEMI-DISCRETE SUPERCELLS.

AN ISOLATED SEVERE THREAT MAY DEVELOP TO THE EAST-NORTHEAST OF
CURRENT TORNADO WATCH 686...ALTHOUGH SURFACE DEWPOINTS HAVE
GENERALLY BEEN DECREASING OVER THE PAST FEW HOURS ACROSS EASTERN
AR/SOUTHEAST MO OWING TO RESIDUAL LOW-LEVEL ANTICYCLONIC
TRAJECTORIES. WHILE THIS PUTS AVAILABLE INSTABILITY/STORM VIGOR A
BIT INTO QUESTION WITH EASTWARD EXTENT...FORCING/VERTICAL SHEAR WILL
BE CONSEQUENTIAL AND INCREASING STORM-SCALE ORGANIZATION MAY
NONETHELESS MAINTAIN A SEVERE THREAT ACROSS AR/SOUTHERN MO
OVERNIGHT. CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED INTO THE
OVERNIGHT FOR AN ADDITIONAL WATCH.

..GUYER.. 12/20/2012

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

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

LAT...LON   33649565 35039451 36069390 37309325 37869101 37199055
            35089203 33729290 33649565

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