549
ACUS11 KWNS 171743
SWOMCD
SPC MCD 171742
MOZ000-KSZ000-OKZ000-NEZ000-172015-
MESOSCALE DISCUSSION 0474
NWS STORM PREDICTION CENTER NORMAN OK
1242 PM CDT FRI APR 17 2026
AREAS AFFECTED...PORTIONS OF THE SOUTHERN/CENTRAL GREAT PLAINS INTO
THE MID-MISSOURI VALLEY
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 171742Z - 172015Z
PROBABILITY OF WATCH ISSUANCE...95 PERCENT
SUMMARY...NUMEROUS SEVERE THUNDERSTORMS ARE EXPECTED TO FORM
ALONG/AHEAD OF A COLD FRONT AND DRYLINE FROM NORTHERN MISSOURI
SOUTHWESTWARD INTO NORTHWESTERN OKLAHOMA THIS AFTERNOON. STORMS WILL
POSE A THREAT FOR ALL HAZARDS, INCLUDING HAIL TO 3-3.5+ INCHES IN
DIAMETER, VERY STRONG WIND GUSTS OF 60-80+ MPH, AND A COUPLE OF
TORNADOES (PERHAPS STRONG). WATCH ISSUANCE WILL BE NEEDED IN THE
NEXT 1-2 HOURS.
DISCUSSION...LATEST MESOANALYSIS DEPICTS A STRONGLY UNSTABLE AIR
MASS IN PLACE AHEAD OF A TRIPLE POINT OVER NORTHWESTERN OKLAHOMA AND
THE ASSOCIATED COLD FRONT/DRYLINE. TEMPERATURES IN THE UPPER-70S F
AND DEWPOINTS IN THE MID/UPPER-60S ARE CONTRIBUTING TO STRONG
INSTABILITY OF 2000-3000+ J/KG MLCAPE ACROSS THE REGION PER LATEST
MESOANALYSIS. LOW-LEVEL CONVERGENCE IS FORECAST TO LEAD TO
CONVECTION INITIATION NEAR THE TRIPLE POINT AND ALONG THE COLD
FRONT/PREFRONTAL CONFLUENCE ZONE THROUGH THE AFTERNOON. STRONG
SOUTHWESTERLY FLOW (50+ KTS AT 4-5 KM AGL PER REGIONAL VWPS) IS
CONTRIBUTING TO EFFECTIVE BULK SHEAR OF 40-50 KTS (LOCALLY GREATER
NEAR THE TRIPLE POINT), WHICH WILL SUPPORT SUPERCELLS WITH INITIAL
STORM FORMATION. STEEP MID-LEVEL LAPSE RATES (AS SAMPLED BY THE 12Z
OUN/TOP/SGF SOUNDINGS AND RECENT ACARS PROFILES), ELONGATED
HODOGRAPHS, AND AMPLE BUOYANCY WITHIN THE HAIL GROWTH ZONE WILL
SUPPORT THE POTENTIAL FOR HAIL OF 3-3.5+ INCHES IN DIAMETER. STRONG
DOWNDRAFTS (WITH WIND GUSTS UP TO 60-80 MPH) ARE ALSO POSSIBLE GIVEN
THE PRESENCE OF SOME DRIER MID-LEVEL AIR.
THE TORNADO THREAT REMAINS MORE UNCERTAIN AS DEEP-LAYER FLOW IS
LARGELY ORIENTED PARALLEL TO THE COLD FRONT, WHICH MAY YIELD COMPLEX
STORM MODE/INTERACTIONS. GIVEN THE POTENTIAL FOR SUPERCELLULAR MODE
AND STORM/OUTFLOW INTERACTIONS, AT LEAST SOME POTENTIAL FOR A COUPLE
OF TORNADOES (PERHAPS STRONG) APPEARS TO EXIST, HOWEVER. THIS
APPEARS MOST LIKELY WITH ANY SUPERCELL THAT IS ABLE TO REMAIN MORE
DISCRETE INTO THE EVENING HOURS WHEN A STRENGTHENING NOCTURNAL
LOW-LEVEL JET WILL YIELD INCREASINGLY CURVED LOW-LEVEL HODOGRAPHS.
TRENDS WILL CONTINUE TO BE MONITORED, AND A TORNADO WATCH WILL BE
NEEDED WITHIN THE NEXT 1-2 HOURS TO COVER THESE THREATS.
WITH TIME, THE DEVELOPMENT OF A FORWARD-PROPAGATING MCS IS
ANTICIPATED ACROSS MUCH OF THIS AREA, WITH AN ACCOMPANYING
TRANSITION TOWARDS SEVERE WIND GUSTS (80+ MPH WIND GUSTS POSSIBLE)
AND PERHAPS EMBEDDED TORNADOES AS THE PRIMARY THREATS.
..CHALMERS/MOSIER.. 04/17/2026
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...SGF...EAX...TSA...OAX...TOP...ICT...OUN...DDC...
LAT...LON 36559959 37359896 38879741 40089628 40419548 40519443
40279381 39679370 38659397 37659462 36669558 35639699
35079813 34999904 35509967 36559959
MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...75-90 MPH
MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN
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