ZCZC SPCSWODY1 ALL ACUS01 KWNS 061229 SPC AC 061229 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0729 AM CDT MON OCT 06 2003 VALID 061300Z - 071200Z THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 10 ENE CNM 45 WSW CVS 15 SE TCC 40 W AMA 10 E AMA 40 NW CDS 70 ESE LBB 40 ESE BGS 50 WSW SJT 40 NE P07 35 NW P07 40 W FST 10 ENE CNM. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SW IPL 55 W EED 40 SE LAS 40 NNE FLG 80 WNW TCS 10 N TCS 30 N ALM 25 ESE 4CR 20 W LVS 35 ESE ALS 30 SW LHX 35 WSW GCK 30 S GCK 40 SSW P28 20 SE CSM 30 N DUA 30 SE PGO 35 ENE LIT 35 NNW HSV 35 ESE CLT 15 ENE ILM. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 NNW 63S 50 NNW COD 40 NW RIW 10 WNW BPI 40 ENE MLD SUN 40 SSE BKE 30 SSW RDM 30 NNW 4BK. ...THERE IS A SLGT RISK OF SVR TSTMS FOR PORTIONS OF WRN TX AND ERN NM... ...SYNOPSIS... LARGE-SCALE PATTERN OVER THE CONUS WILL BECOME INCREASINGLY PROGRESSIVE THIS FORECAST AS STRONG UPPER-LEVEL JET APPROACHES THE PACIFIC NW COAST FROM THE W. SEVERAL WEAK PERTURBATIONS WILL TRANSLATE THROUGH THIS LONG WAVE PATTERN...WITH THE PRIMARY FEATURE OF INTEREST BEING ZONALLY-ORIENTED VORT MAX/MID-LEVEL COLD POOL WHICH WILL OVERSPREAD OK/TX PNHDL LATE THIS AFTERNOON/THIS EVENING FROM THE N. IN THE LOW-LEVELS...WEAK FRONTAL BOUNDARY CURRENTLY OBSERVED FROM THE TX PERMIAN BASIN ENEWD ACROSS NRN TX AND THEN INTO THE LOWER MS VALLEY...WILL REMAIN QUASI-STATIONARY OR SLOWLY MOVE SWD AS EXPANSIVE RIDGE AXIS IS MAINTAINED FROM THE NERN U.S. INTO THE CNTRL/SRN LOW PLAINS. ...SRN HIGH PLAINS... SLY/SELY LOW-LEVEL FLOW ALONG AND N OF AFOREMENTIONED SURFACE BOUNDARY WILL SUSTAIN A MOIST BOUNDARY-LAYER AIRMASS /SURFACE DEWPOINTS IN THE MID 50S TO LOWER 60S/ TODAY ACROSS ERN NM/WRN TX INTO WRN OK. THIS MOISTURE COUPLED WITH DIURNAL HEATING AND RELATIVELY STEEP LOW-/MID-LEVEL LAPSE RATES WILL CONTRIBUTE TO POCKETS OF MODERATE INSTABILITY WHERE MLCAPES WILL APPROACH 1000-1500 J/KG. THE PRIMARY CONCERN THIS FORECAST IS WHETHER LOW-LEVEL FORCING WILL BE SUFFICIENT TO INITIATE DEEP...MOIST CONVECTION WHERE THE GREATEST INSTABILITY AND VERTICAL WIND SHEAR WILL CO-EXIST. CURRENT MODEL GUIDANCE SUGGESTS THAT THE STRONGEST LOW-LEVEL WINDS AND RESULTANT UPSLOPE COMPONENT WILL OCCUR OVER SERN NM SWD INTO THE HIGHER TERRAIN OF SWRN TX. FARTHER N...ANY INITIATION FOCI CURRENTLY REMAIN MORE AMBIGUOUS WITH ONLY A WEAK SURFACE RESPONSE EXPECTED LATER TODAY AHEAD OF APPROACHING MID-LEVEL SHORTWAVE TROUGH. CURRENT THINKING IS THAT ISOLATED TSTMS WILL DEVELOP BY LATE AFTERNOON/EARLY EVENING ALONG ERN SLOPES OF HIGHER TERRAIN FROM SERN NM INTO SWRN TX WHERE LOW-LEVEL UPSLOPE WILL BE THE STRONGEST. OVER NERN NM...THE TX S PLAINS INTO THE TX/OK PNHDLS...CONFIDENCE IN TSTM DEVELOPMENT IS LOWER AS INITIATION WILL LIKELY BE DEPENDENT ON ANY MESOSCALE BOUNDARIES THAT MAY BECOME MORE EVIDENT LATER IN THE DAY. THE PRESENCE OF 25-30KT NWLY MID-LEVEL WINDS ABOVE SURFACE ELY/SELY COMPONENT WILL RESULT IN SUFFICIENT DEEP-LAYER SHEAR FOR STORM ORGANIZATION...WITH THE POTENTIAL FOR UPDRAFT ROTATION/SUPERCELL STRUCTURES. LARGE HAIL WILL BE THE PRIMARY SEVERE WEATHER THREAT GIVEN THE STEEP LAPSE RATES AND FAVORABLY LOW WBZ HEIGHTS. ELSEWHERE...SURFACE DEWPOINTS IN THE MID 60S TO AROUND 70F AND DAYTIME HEATING WILL LEAD TO AN INCREASINGLY UNSTABLE AIRMASS LATER THIS MORNING AND AFTERNOON AHEAD OF MCS CURRENTLY MOVING SEWD THROUGH CNTRL TX. ALTHOUGH DEEP-LAYER SHEAR WILL BE COMPARATIVELY WEAKER THAN POINTS TO THE W AND N...ISOLATED STRONG WIND GUSTS WILL BE POSSIBLE WITH THE MORE INTENSE CONVECTIVE ELEMENTS. ..MEAD/BANACOS.. 10/06/2003 ...NOTICE... FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3. THE INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED. $$ |