234
ACUS11 KWNS 190311
SWOMCD
SPC MCD 190310
OKZ000-190445-
MESOSCALE DISCUSSION 0781
NWS STORM PREDICTION CENTER NORMAN OK
1010 PM CDT MON MAY 18 2026
AREAS AFFECTED...PORTIONS OF NORTHERN OKLAHOMA
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 190310Z - 190445Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...THE SEVERE THREAT MAY INCREASE OVER NORTHERN OK OVER THE
NEXT FEW HOURS AS STORMS BACK-BUILD SOUTHWESTWARD ALONG A SOUTHWARD
DRIFTING COLD FRONT. SEVERE GUSTS ARE THE MAIN THREAT, THOUGH AN
INSTANCE OR TWO OF HAIL OR A TORNADO ARE POSSIBLE. CONVECTIVE TRENDS
ARE BEING MONITORED FOR THE NEED OF A WW ISSUANCE.
DISCUSSION...ROBUST MULTICELLULAR CONVECTION, WITH A HISTORY OF
MEASURED SEVERE GUSTS, HAS BEEN STEADILY BACK-BUILDING
WEST-SOUTHWESTWARD ALONG AND IMMEDIATELY BEHIND A SOUTHWARD SAGGING
COLD FRONT. DESPITE WEAK UPPER SUPPORT, STRONG LOW-LEVEL CONVERGENCE
HAS BEEN SUPPORTING PERSISTENT CONVECTIVE DEVELOPMENT, ESPECIALLY
GIVEN A 50 KT SOUTHERLY LOW-LEVEL JET BISECTING THE COLD FRONT
NEARLY PERPENDICULARLY. AHEAD OF THE FRONT, UPPER 60S F SURFACE
DEWPOINTS BENEATH 8-9 C/KM MID-LEVEL LAPSE RATES ARE YIELDING 3000+
J/KG MLCAPE PER THE 00Z OUN/LMN SOUNDINGS AND 02Z MESOANALYSIS.
THESE SAME DATA SOURCES ALSO DEPICT SIZEABLE LOW-LEVEL HODOGRAPHS
WITH 300 M2/S2 EFFECTIVE SRH AND 40+ KTS OF EFFECTIVE BULK SHEAR. AS
SUCH, THE AMBIENT ENVIRONMENT CLEARLY SUPPORTS SEVERE POTENTIAL.
THE PRIMARY UNCERTAINTY IS HOW FAR SOUTHWEST CONVECTION WILL
INITIATE ALONG THE SOUTHWARD-SAGGING FRONT, AND THE TIMING FOR
STORMS TO PROPAGATE INTO OK. THE CURRENT THINKING IS THAT STORMS
CAPABLE OF SEVERE GUSTS WILL EVENTUALLY PROPAGATE SOUTHWARD INTO
NORTH-CENTRAL AND NORTHEAST OK. AN INSTANCE OR TWO OF SEVERE HAIL
COULD ACCOMPANY THE STRONGER STORM CORES, AND A TORNADO CANNOT BE
RULED OUT IF A ROBUST UPDRAFT CAN OUTPACE THE COLD FRONT. CONVECTIVE
TRENDS WILL CONTINUE TO BE MONITORED FOR CONVECTIVE PROPAGATION INTO
OK.
..SQUITIERI/MOSIER.. 05/19/2026
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...TSA...OUN...
LAT...LON 36779919 36929821 36999709 36969623 36739582 36449572
36099589 35879664 35809745 35909809 36089856 36429904
36779919
MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page