Mesoscale Discussion 1897

Issued

Sep 5, 2012, 5:31 PM CDT (22:31 UTC)

Expired

Sep 5, 2012, 7:00 PM CDT

In force

89 min

Issued by

the Storm Prediction Center

235 
ACUS11 KWNS 052231
SWOMCD
SPC MCD 052231 
KYZ000-TNZ000-MSZ000-MOZ000-ARZ000-060000-

MESOSCALE DISCUSSION 1897
NWS STORM PREDICTION CENTER NORMAN OK
0531 PM CDT WED SEP 05 2012

AREAS AFFECTED...NORTHEAST AR AND WESTERN/MIDDLE TN TO
CENTRAL/EASTERN KY

CONCERNING...SEVERE THUNDERSTORM WATCH 620...621...

VALID 052231Z - 060000Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
620...621...CONTINUES.

SUMMARY...DAMAGING WINDS AND PERIODIC SEVERE HAIL WILL REMAIN
POSSIBLE THROUGH EARLY EVENING...ESPECIALLY ACROSS PORTIONS OF
NORTHEAST AR AND WESTERN/NORTHERN TN...AND TO A LESSER EXTENT ACROSS
EASTERN KY. SEVERE TSTM WATCHES 620/621 CONTINUE. ALSO MONITORING
FOR AN ADDITIONAL WATCH /40 PERCENT PROBABILITY/ ACROSS PORTIONS OF
TN/FAR EASTERN AR/FAR NORTHERN MS...ALTHOUGH THE NEED FOR A NEW
WATCH IS UNCLEAR AND/OR LOCAL WFO EXTENSION/S MAY BE MORE PRUDENT.

DISCUSSION...WITH A SURFACE COLD POOL/MESO-HIGH NOTED ALONG THE OH
RIVER VICINITY...AN EXTENSIVE NORTHEAST-SOUTHWEST ORIENTED SQUALL
LINE CONTINUES TO SLOW BUT STEADILY PROGRESS EAST-SOUTHEASTWARD
ACROSS EAST-CENTRAL/SOUTH-CENTRAL KY INTO NORTHERN PORTIONS OF
MIDDLE TN. FARTHER SOUTHEAST...SOMEWHAT MORE ISOLATED AND MORE
VIGOROUS TSTMS ARE OCCURRING IN VICINITY OF THE MO
BOOTHEEL/NORTHEAST AR/WESTERN TN AS OF 2215Z. 

SIMILAR TO CURRENT TRENDS...THE STRONGEST TSTMS ARE LIKELY TO
PERSIST THROUGH EARLY EVENING ACROSS FAR EASTERN AR AND
WESTERN/NORTHERN TN AND PERHAPS EVENTUALLY FAR NORTHERN PORTIONS OF
MS/NORTHWEST AL. HERE...THE AIRMASS REMAINS WARM/UNSTABLE WITH
TEMPERATURES IN THE LOWER 90S F AND MLCAPE ESTIMATED TO BE ON THE
ORDER OF 2000-2500 J/KG. REGIONAL WSR-88D VWPS DERIVED WINDS FORM
OHX/PAH/HPX SAMPLE A STEADY INCREASE IN WEST-NORTHWEST WINDS
ALOFT...WHICH WILL AID STORM ORGANIZATION AS STORMS CONTINUE TO
CONGEAL/SPREAD SOUTHEASTWARD THROUGH EARLY EVENING. DAMAGING WINDS
AND SOME SEVERE HAIL WILL REMAIN POSSIBLE PRIOR TO EVENTUAL
POST-SUNSET COOLING OF THE BOUNDARY LAYER AND A PROBABLE DIMINISHING
INTENSITY TREND.

..GUYER.. 09/05/2012

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

ATTN...WFO...MRX...JKL...ILN...LMK...OHX...PAH...MEG...LZK...

LAT...LON   35329114 36119028 36618798 36888600 37868472 38458414
            38408351 37068366 36038583 34988883 35329114

Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in Kentucky, 2012Mesoscale Discussions in Arkansas, 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.