Todays Severe weather TX OK KS & MO T-storms elsewhere see maps livewxradar/modules.php?name=Content&pa=showpage&pid=37 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0744 AM CDT TUE APR 01 2014 VALID 011300Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS NW TX -- MID-AFTN INTO EARLY EVENING... ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS ERN KS/WRN MO TONIGHT... ...SYNOPSIS... PROGRESSIVE UPPER-AIR PATTERN FCST TO CONTINUE THROUGH PERIOD. STG/COMPACT SHORTWAVE TROUGH AND EMBEDDED LOW -- NOW EJECTING NEWD ACROSS WI...WRN LS AND MN ARROWHEAD -- WILL MOVE EWD ACROSS UPPER GREAT LAKES AND SRN/CENTRAL ONT. FARTHER W...COMPLEX AREA OF TROUGHING...WITH EMBEDDED VORTICITY MAXIMA OVER GREAT BASIN AND OFFSHORE NRN CA -- IS EVIDENT IN MOISTURE-CHANNEL IMAGERY. THIS REGIME IS EXPECTED TO EVOLVE INTO POSITIVELY TILTED TROUGH FROM YELLOWSTONE REGION SWWD ACROSS NV AND COASTAL CENTRAL CA BY 12Z. VERY WEAK SRN-STREAM PERTURBATION NOW OVER CENTRAL/SRN BAJA SHOULD MOVE NEWD ACROSS NRN MEX TO TX BIG BEND REGION BY 00Z...TOO FAR S TO INFLUENCE SVR POTENTIAL DESCRIBED BELOW. 11Z SFC ANALYSIS SHOWED COLD FRONT -- RELATED TO INITIAL MID-UPPER LEVEL SHORTWAVE TROUGH -- FROM WRN LOWER MI AND NRN INDIANA SWWD ACROSS SERN MO. FRONT BECAME QUASISTATIONARY FROM THERE SWWD TO WEAK WAVE LOW OVER NW TX...BETWEEN DYS/CDS/SPS..THEN EXTENDED GENERALLY WWD TO SERN NM. DRYLINE WAS DRAWN FROM LOW SSWWD TO NRN COAHUILA JUST W DRT. DRYLINE IS FCST TO RETREAT NWWD TOWARD TX CAPROCK FROM MID-LATE AFTN THROUGH OVERNIGHT HOURS...WHILE WARM FRONT MOVES NNWWD ACROSS OK AND NWRN AR. ...NW TX -- MID-AFTN INTO EARLY EVENING... PROBABILITIES ARE MAINTAINED WITH ONLY SMALL SPATIAL ADJUSTMENTS...FOR SUPERCELL RISK WITH ATTENDANT LARGE HAIL AND SVR WIND. MAIN LIMITING/UNCERTAINTY FACTORS WILL BE PRESENCE OF STG ANTECEDENT CAPPING...AND STRENGTH OF LIFT REQUIRED TO OVERCOME THAT. DRYLINE IS EXPECTED TO MIX EWD THEN RETREAT WWD THIS AFTN INTO EARLY EVENING...AS MOISTURE ADVECTION/TRANSPORT CONTINUES TO ITS E. STG DIABATIC HEATING AND BOUNDARY-LAYER MIXING IS EXPECTED ALONG MOST OF DRYLINE...ENOUGH THAT NEARBY MOIST-SECTOR DEW POINTS MAY DECREASE FOR 2-3 HOURS AROUND 22Z BEFORE RISING AGAIN. HEATING MAY BE TEMPERED SLIGHTLY BY PATCHES OF VARIABLY THICK CIRRUS...AS EVIDENT IN 12Z MAF RAOB AND UPSTREAM IR IMAGERY ATTM...AND IN HIGH-RH UPPER LEVELS IN FCST SOUNDINGS. THAT LENDS SOME UNCERTAINTY TO VIGOR OF LIFT...AS DOES BACKING OF DRYLINE LATE. STILL...AREAS OF TCU SHOULD DEVELOP ATOP DEEPLY MIXED BOUNDARY LAYER AND NEAR DRYLINE DURING 21-00Z TIME FRAME...AMIDST 1500-2000 J/KG MLCAPE AND 40-50 KT EFFECTIVE SHEAR MAGNITUDE. ONE OR TWO SUPERCELLS MAY EVOLVE FROM THAT CONVECTION...PERHAPS WITH SOME SPLITTING IN EARLY STAGES BEFORE HODOGRAPHS BECOME MORE STRONGLY CURVED. ANY SUCH STORMS LASTING PAST ABOUT 23Z WILL BE MET BY INCREASING MOISTURE FROM SLY/SELY INFLOW SECTOR. ORGANIZED STORM-SCALE ROTATION WILL BE NEEDED IN ORDER TO MAINTAIN UPDRAFT CONTINUITY PAST ABOUT 00Z...AS MLCINH INCREASES BOTH WITH TIME AND WITH EWD EXTENT. TORNADO POTENTIAL APPEARS TOO LOW/CONDITIONAL AND BRIEF FOR MORE THAN MRGL PROBABILITIES ATTM...THOUGH ONE CANNOT BE RULED OUT. SFC-BASED CONVECTION IS EXPECTED TO DISSIPATE THIS EVENING AS CAPPING BECOMES TOO STG WHILE NEAR-SFC PARCELS DIABATICALLY COOL. ...ERN KS/WRN MO TONIGHT... TSTMS MAY DEVELOP THIS AFTN IN THIS REGION...RELATED TO ELEVATED WAA CONVEYOR CHARACTERIZED BY MEAGER MOISTURE. SUCH ACTIVITY SHOULD POSE LITTLE OR NO SVR THREAT. ANOTHER ROUND OF CONVECTION WITH SCATTERED TSTMS IS FCST TO DEVELOP MAINLY AFTER 06Z ACROSS PORTIONS SRN/ERN KS AND MOVE GENERALLY EWD INTO WRN MO PRIOR TO 12Z. ELEVATED SUPERCELLS AND ORGANIZED MULTICELLS ARE POSSIBLE...OFFERING LARGE HAIL. DURING 06-12Z TIME FRAME...RAPIDLY INCREASING MOISTURE IS EXPECTED WITHIN AIR MASS BEING ISENTROPICALLY LIFTED TO LFC N OF SFC WARM FRONT. AS THIS OCCURS BENEATH STEEP MIDLEVEL LAPSE RATES...TIME SERIES OF FCST SOUNDINGS REASONABLY SUGGESTS NEAR-SATURATION OF LAYER NEAR 850 MB WITH DEW POINTS 12-14 DEG C...AND REMOVAL OF CINH. ELEVATED MUCAPE 2000-2500 J/KG IS POSSIBLE INVOF KS/OK BORDER...DIMINISHING NWD AND ALSO WITH TIME OVER ERN KS AS CONVECTIVE COVERAGE BLOSSOMS. SOME SUPERCELLS ROOTED ALOFT ARE POSSIBLE...GIVEN FCST EFFECTIVE SRH/SHEAR MAGNITUDE OF 200-300 J/KG AND 45-55 KT RESPECTIVELY. AS SUCH...LARGE HAIL IS EXPECTED TO BE PRIMARY CONCERN. ..EDWARDS/SMITH.. 04/01/2014
Posted on: Tue, 01 Apr 2014 16:07:07 +0000