Mesoscale Discussion 1821

Issued

Oct 7, 2014, 3:52 AM CDT (08:52 UTC)

Expired

Oct 7, 2014, 5:15 AM CDT

In force

83 min

Issued by

the Storm Prediction Center

Chance of a watch

20%

The Memphis radar (KNQA), 123 km from the middle of the area, began a volume at 08:52 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.

040 
ACUS11 KWNS 070852
SWOMCD
SPC MCD 070852 
TNZ000-KYZ000-MOZ000-ARZ000-071015-

MESOSCALE DISCUSSION 1821
NWS STORM PREDICTION CENTER NORMAN OK
0352 AM CDT TUE OCT 07 2014

AREAS AFFECTED...PARTS OF S CNTRL/SERN MO...NERN AR...ADJACENT WRN
TN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 070852Z - 071015Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...THE RISK FOR SEVERE SURFACE GUSTS WITH EVOLVING STORMS
APPEARS LOW...BUT LOCALLY SEVERE HAIL MAY REMAIN POSSIBLE AT LEAST
INTO THE 11-13Z TIME FRAME.  A WATCH IS NOT CURRENTLY
ANTICIPATED...BUT TRENDS ARE BEING MONITORED.

DISCUSSION...VIGOROUS ONGOING CONVECTIVE DEVELOPMENT...NORTH THROUGH
SOUTH SOUTHEAST OF WEST PLAINS MO...APPEARS TO HAVE BEEN SUPPORTED
BY AN AREA OF ENHANCED FORCING FOR LARGE-SCALE ASCENT...LARGELY DUE
TO LOW-LEVEL WARM ADVECTION DRIVEN BY A 40-50 KT WESTERLY 850 MB
SPEED MAXIMA.  THE LATEST RAPID REFRESH SUGGESTS THAT THIS FEATURE
WILL NOSE FROM SOUTHWESTERN MISSOURI TOWARD WESTERN KENTUCKY AND
TENNESSEE DURING THE NEXT FEW HOURS...BUT ASSOCIATED FORCING FOR
UPWARD VERTICAL MOTION MAY BEGIN TO WEAKEN TOWARD THE 11-13Z TIME
FRAME.

UNTIL THIS OCCURS.../IN THE PRESENCE OF STRONG VERTICAL
SHEAR/...THERMODYNAMIC PROFILES CHARACTERIZED BY RELATIVELY COOL
MID-LEVEL TEMPERATURES AND LINGERING WEAK TO MODESTLY STEEP
MID-LEVEL LAPSE RATES...SUPPORTING CAPE LOCALLY AS HIGH AS 1000
J/KG...MAY REMAIN SUPPORTIVE OF SEVERE HAIL IN ISOLATED TO WIDELY
SCATTERED STRONGEST CELLS.  IT MAY NOT BE OUT OF THE QUESTION THAT
ACTIVITY COULD CONSOLIDATE INTO A MORE ORGANIZED CLUSTER ACROSS
PARTS OF NORTHEASTERN ARKANSAS AND THE MISSOURI BOOTHEEL INTO
WESTERN TENNESSEE.  HOWEVER...WITH ANY DEVELOPING SURFACE COLD
POOL...THE RISK FOR WIND GUSTS REACHING SEVERE LIMITS SEEMS LIKELY
TO REMAIN LOW...OR AT LEAST SHORTLY-LIVED...DUE TO THE WEAKENING
FORCING FOR ASCENT...AND THE RELATIVELY COOL/STABLE DOWNSTREAM
BOUNDARY LAYER.

..KERR/KERR.. 10/07/2014

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

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

LAT...LON   37029185 37079030 36468913 35668911 35148974 35509100
            36229205 37029185

Mesoscale Discussions in Arkansas, 2014Mesoscale Discussions in Missouri, 2014Mesoscale Discussions in Tennessee, 2014Every mesoscale discussion in 2014

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.