Mesoscale Discussion 140

Issued

Feb 20, 2012, 5:37 PM CST (23:37 UTC)

Expired

Feb 20, 2012, 7:30 PM CST

In force

113 min

Issued by

the Storm Prediction Center

The Tulsa radar (KINX), 61 km from the middle of the area, began a volume at 23:40 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.

623 
ACUS11 KWNS 202338
SWOMCD
SPC MCD 202337
MOZ000-ARZ000-OKZ000-KSZ000-TXZ000-210130-

MESOSCALE DISCUSSION 0140
NWS STORM PREDICTION CENTER NORMAN OK
0537 PM CST MON FEB 20 2012

AREAS AFFECTED...PORTIONS ERN OK...ERN KS...WRN AR...SWRN MO.

CONCERNING...SEVERE THUNDERSTORM WATCH 33...34...

VALID 202337Z - 210130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
33...34...CONTINUES.

EACH WW MAY BE CLEARED FROM W-E ONCE PRIMARY CONVECTIVE BAND PASSES.
SVR POTENTIAL IS EXPECTED TO DIMINISH WITH EWD EXTENT AND WITH TIME
ACROSS WW 34...AS TSTMS MOVE INTO PROGRESSIVELY WEAKER MLCAPE
ENVIRONMENT.  HOWEVER...THREAT FOR DAMAGING GUSTS MAY CONTINUE E OF
AREAS WHERE OBJECTIVE ANALYSES INDICATE LITTLE OR NO MLCAPE...GIVEN
INHERENT UNCERTAINTIES REGARDING THEIR RESOLUTION OF FAST-EVOLVING
AND MRGL MESOSCALE PARAMETERS.

23Z SFC MESOANALYSIS SHOWED CYCLONE OVER S-CENTRAL NEB OVER
HSI/GRI/JYR AREA...COLD FRONT SWD ACROSS CENTRAL KS TO NEAR END THEN
SSWWD PAST SPS/ABI TO BETWEEN SJT-FST.  DRYLINE WAS ANALYZED AHEAD
OF COLD FRONT...FROM NEAR EWK SSEWD TO JUST E SWO...THEN SSWWD NEAR
ADM AND OVER FTW AREA.  COLD FRONT SHOULD CATCH DRYLINE DURING NEXT
3-4 HOURS OVER OK AND N-CENTRAL TX.  COMBINED BOUNDARY SHOULD MOVE
EWD TO NEAR OK/AR BORDER BY ABOUT 04Z...WHILE ACTING AS WRN BOUND OF
CONVECTIVE POTENTIAL.  HOWEVER...BULK OF ACTIVITY SHOULD REMAIN IN
ZONE OF LOW-LEVEL CONVERGENCE PRECEDING THAT BOUNDARY...WHICH
PRESENTLY IS TRANSLATING EWD 35-40 KT...WITH FASTER NEWD MOTIONS FOR
INDIVIDUAL CELLS/BOWS.  NRN FRINGE OF THIS ZONE WILL MOVE MORE
SLOWLY NEWD ACROSS NERN KS...WITH MORE WIDELY SCATTERED CONVECTIVE
COVERAGE.

SFC MOIST AXIS...WITH DEW POINTS MAINLY MID-40S F EXCEPT FOR LOW 50S
NEAR RED RIVER...WAS DRAWN ABOUT 50 NM AHEAD OF TSTM BAND.  TSTMS
WILL OVERTAKE THAT AXIS THROUGH 01Z.  HOWEVER...MODIFIED FCST
SOUNDINGS SUGGEST MLCAPE 50-200 J/KG MAY PERSIST AS FAR E AS SWRN
MO/NWRN AR AND TOP AREA IN SUPPORT OF AT LEAST SPORADIC SVR THREAT.
STG DEEP-LAYER WIND FIELDS ARE EVIDENT -- E.G. 3-4 KM AGL WINDS
70-75 KT IN PRC PROFILER...60-70 KT AT INX VWP...AND 55-65 KT AT NDS
PROFILER.  THIS STG FLOW WILL SHIFT ENEWD WITH TIME AND IN STEP WITH
TSTM BAND...UNTIL CONVECTION DISSIPATES DUE TO LACK OF INSTABILITY.
IN MEANTIME...POTENTIAL EXISTS FOR MOMENTUM TRANSFER TO SFC IN FORM
OF DAMAGING GUSTS...ESPECIALLY INVOF EMBEDDED BOW/LEWP
MESOCIRCULATIONS.

FARTHER N...REF SPC MESOSCALE DISCUSSION 139 FOR SHORT-TERM SVR
THREAT ACROSS PORTIONS NRN KS AND SRN NEB.

..EDWARDS.. 02/20/2012

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

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

LAT...LON   33929725 35169637 36619628 38129638 38819677 39299708
            39429635 39329577 39159527 38459454 37909362 36339355
            35379390 34389490 34019578 33799681 33929725

Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Kansas, 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.