12Z CONVECTIVE OUTLOOK
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
PORTIONS OF SWRN KS...NWRN OK AND THE OK/TX PNHDLS...
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID MO VALLEY SWWD
INTO SRN HIGH PLAINS...
...SYNOPSIS...
UPPER LOW AND ATTENDANT SHORT WAVE TROUGH CURRENTLY LIFTING NEWD
THROUGH THE NRN AND CNTRL HIGH PLAINS WILL CONTINUE NEWD TODAY
THROUGH THE DAKOTAS AND UPPER MS VALLEY INTO ERN SASKATCHEWAN AND
MANITOBA BY MORNING. MEANWHILE...NEXT SHORT WAVE TROUGH
AND ASSOCIATED MID-LEVEL JET STREAK OVER THE GREAT BASIN WILL
TRANSLATE SEWD THROUGH THE FOUR CORNER REGION TODAY...EMERGING INTO
THE CNTRL AND SRN HIGH PLAINS TONIGHT.
IN THE LOW-LEVELS...SURFACE LOW ATTENDANT TO MAIN UPPER LOW WILL
DEVELOP NEWD FROM ERN ND INTO WRN ONTARIO BY THE END OF THE PERIOD
WHILE SECONDARY LEE CYCLONE CONSOLIDATES OVER SERN CO INTO NERN NM
LATER TODAY. WHILE ASSOCIATED COLD FRONT WILL ASSUME A SLOW EWD
PROGRESSION THROUGH THE NRN PLAINS AND UPPER MS VALLEY...THIS
BOUNDARY IS FORECAST TO BECOME QUASI-STATIONARY FROM ERN NEB/WRN IA
SWWD INTO CNTRL KS. SRN HIGH PLAINS CYCLOGENESIS MAY CAUSE WRN
EXTENSION OF THIS BOUNDARY TO RETREAT SLIGHTLY BY AFTERNOON OVER THE
NRN TX/OK PNHDLS AND FAR SWRN KS.
...UPPER MS VALLEY INTO MID MO VALLEY...
SCATTERED TSTMS ARE EXPECTED TO BE ONGOING AT THE ONSET OF THE
PERIOD ALONG FRONT...LARGELY DRIVEN BY DEEP LAYER FORCING FOR ASCENT
ASSOCIATED WITH UPPER LOW AND ATTENDANT SHORT WAVE TROUGH. CLOUDS
AND/OR PRECIPITATION WILL LINGER THROUGH MUCH OF THE DAY...LIMITING
DESTABILIZATION ESPECIALLY ACROSS THE ERN DAKOTAS INTO WRN MN.
LATEST MODEL GUIDANCE DOES SUGGEST THAT AIR MASS OVER ERN NEB/WRN IA
MAY DESTABILIZE SUFFICIENTLY SUCH THAT DIURNAL STORMS WILL BE
POSSIBLE BY AFTERNOON ALONG STALLED FRONT.
THE COMBINATION OF MLCAPES OF AROUND 1000 J/KG AND EFFECTIVE BULK
SHEARS /EBS/ OF 30-40 KT INDICATE THE POTENTIAL FOR ORGANIZED
STORMS...A FEW OF WHICH COULD BE SUPERCELLS WITH THE POTENTIAL FOR
MAINLY LARGE HAIL AND STRONG WIND GUSTS. TSTMS SHOULD GRADUALLY
EVOLVE INTO MORE A LINEAR STRUCTURE WITH TIME WITH THE HAIL/WIND
THREAT CONTINUING INTO THIS EVENING.
...KS INTO THE SRN HIGH PLAINS...
00Z REGIONAL SOUNDINGS ACROSS THE SRN PLAINS INDICATE THAT
BOUNDARY LAYER MOISTURE CONTINUES TO SLOWLY IMPROVE WITH MEAN MIXING
RATIOS OF 12-15 G/KG OBSERVED OVER THE LOWER ELEVATIONS OF TX/OK.
HOWEVER...OBSERVED SOUNDING DATA OVER THE SWRN U.S. INTO SRN HIGH
PLAINS SHOWED GENERALLY 6.5-7.0 C/KM MID-LEVEL LAPSE RATES WHICH
WILL TEMPER THE DEGREE OF WARM SECTOR INSTABILITY TODAY.
NONETHELESS...THE PRESENCE OF LOW/MID 60S DEWPOINTS AND DAYTIME
HEATING SHOULD CONTRIBUTE TO MLCAPES APPROACHING 1500-2500 J/KG BY
LATE AFTERNOON S OF FRONT.
TSTMS ARE EXPECTED TO BECOME INCREASINGLY LIKELY ALONG FRONT BY MID
TO LATE AFTERNOON FROM CNTRL KS SWWD INTO SWRN KS THE OK AND NRN TX
PNHDLS. ADDITIONAL STORMS WILL LIKELY INITIATE AT THIS TIME OVER
THE HIGHER TERRAIN OF S-CNTRL CO/N-CNTRL NM...PRIOR TO
MOVING/DEVELOPING EWD ALONG STATIONARY OR RETREATING FRONTAL
BOUNDARY.
THE STRONGEST DEEP LAYER VERTICAL SHEAR /EBS OF 45-55 KT/ WILL EXIST
OVER THE SRN HIGH PLAINS THROUGH THIS EVENING WITH EBS OF GENERALLY
30-40 KT FORECAST FARTHER E ALONG FRONT OVER CNTRL KS.
GIVEN THE DEGREE OF INSTABILITY...SUPERCELLS APPEAR LIKELY
ESPECIALLY ACROSS THE MODERATE RISK AREA. LARGE HAIL /SOME
SIGNIFICANT/ AND TORNADOES WILL BE THE PRIMARY SEVERE WEATHER
THREATS WITH THE MOST INTENSE STORMS. POTENTIAL FOR A STRONG
TORNADO OR TWO WILL EXIST THIS EVENING /00-03Z/ WITH ANY MATURE
SUPERCELLS AS 0-1 KM SRH INCREASES TO 200-300 M2/S2.
STORMS WILL LIKELY GROW UPSCALE INTO AN MCS OVERNIGHT WITH A HIGH
WIND AND HAIL THREAT SPREADING INTO CNTRL KS AND WRN OK.