ZCZC SPCSWODY1 ALL ACUS01 KWNS 121255 SPC AC 121255 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0755 AM CDT TUE AUG 12 2003 VALID 121300Z - 131200Z GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 W CZZ 45 NNE TRM 35 SW LAS 35 ESE EKO 25 NW BOI 35 S BKE 40 ESE RDM 70 NNE LMT 45 NNE MFR 10 SSE EUG 50 ENE BLI ...CONT... 20 WNW RRT 50 E DIK 45 NNW RAP 40 SSW BFF 10 N CAO 40 NW MAF BGS 25 E P28 35 WSW IRK 30 ENE RFD 15 SSE OSC ...CONT... 40 WNW 3B1 40 NW EPM ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A BELT OF STRONG SWLYS WILL EXIST ACROSS THE PACIFIC NW AND NRN ROCKIES TODAY AS AN UPPER-RIDGE DOMINATES THE INTERMOUNTAIN WEST AND NRN PLAINS STATES. AT THE SFC...A COLD FRONT WILL MOVE SWD ACROSS MT WITH A LEE TROUGH IN PLACE ACROSS THE HIGH PLAINS. ...SRN AND ERN TX/ERN OK/ERN AR/WRN LA... ALTHOUGH LOW-LEVEL MOISTURE HAS BEEN DEPLETED SOMEWHAT ACROSS THE SRN PLAINS...SFC DEWPOINTS IN THE MID TO UPPER 60S F STILL EXIST. SFC HEATING WILL LIKELY RESULT IN LOW-END MODERATE INSTABILITY ALONG THE TX COASTAL PLAIN BY AFTERNOON WITH MLCAPE VALUES OF 1000 TO 1200 J/KG. FORECAST SOUNDINGS SHOW SLIGHTLY STEEPER LAPSE RATES WILL EXIST ACROSS NE TX AND ERN OK WHICH SHOULD RESULT IN STRONGER INSTABILITY THERE THIS AFTERNOON WITH MLCAPE OF 1500 TO 2500 J/KG. SCATTERED CONVECTION ONGOING ACROSS FAR NERN TX WILL LIKELY EXPAND THIS MORNING AS INSTABILITY AND LARGE-SCALE FORCING INCREASES SOME AHEAD OF A VORT MAX MOVING SWD THROUGH ERN KS EVIDENT ON WV IMAGERY. FORECAST SOUNDINGS SHOW WEAK DEEP LAYER SHEAR ACROSS THE REGION SUGGESTING THE MODE OF CONVECTION WILL BE PULSE IN NATURE. THE STRONGER INSTABILITY AND SLIGHTLY STEEPER LAPSE RATES ACROSS NERN TX AND ERN OK MAY POSE A MINIMAL THREAT FOR ISOLATED HAIL HOWEVER THE WEAK SHEAR SHOULD LIMIT THE POTENTIAL BELOW SLIGHT RISK CRITERIA. OTHERWISE...A MARGINAL THREAT FOR A FEW WET MICROBURSTS SHOULD EXIST FROM ERN OK SWD ACROSS THE TX COASTAL PLAIN. ...MT/ERN WY... A WEAK SHORTWAVE MOVING NEWD ACROSS FAR WRN WY WILL INCREASE LARGE-SCALE ASCENT ACROSS CNTRL MT TODAY. CONVECTION ASSOCIATED WITH THE WAVE IS ONGOING ACROSS FAR SWRN MT AND ERN ID. THIS CONVECTION WILL LIKELY EXPAND IN COVERAGE WITH NEW CONVECTION DEVELOPING ACROSS SRN MT AND ERN WY THIS AFTERNOON. SFC DEWPOINTS IN THE 50S AND LOWER 60S WILL BE IN PLACE WHICH COUPLED WITH STRONG SFC HEATING...SHOULD RESULT IN LOW-END MODERATE INSTABILITY BY AFTERNOON ACROSS SERN MT WITH MARGINAL INSTABILITY EXPECTED OVER SCNTRL MT. FORECAST SOUNDINGS SHOW THE STRONGEST DEEP LAYER SHEAR OF 45 KT WILL REMAIN OVER THE MTNS OF SCNTRL MT WITH WEAKER SHEAR FORECAST FARTHER EAST WHERE INSTABILITY WILL BE STRONGER. THIS SUGGESTS A FEW ORGANIZED STORMS WILL BE POSSIBLE ESPECIALLY IN LOCALIZED AREAS OF GREATER INSTABILITY AND SHEAR. IF STRONG CONVECTION DEVELOPS...THE ACTIVITY WOULD BE ISOLATED WITH A MARGINAL THREAT FOR MICROBURSTS AND/OR HAIL CONSIDERING THE INVERTED V PROFILES AND STEEP LAPSE RATES. BUT THE SEVERE WEATHER THREAT SHOULD BE TOO LOW FOR A SLIGHT RISK ATTM. ...ERN AZ/WRN NM... AS SFC TEMPS HEAT UP LATE THIS MORNING...MOUNTAIN CONVECTION WILL LIKELY DEVELOP ALONG THE MOGOLLON RIM AND WRN NM PEAKS. FORECAST SOUNDINGS SHOW ONLY MARGINAL INSTABILITY AND SHEAR PROFILES IN PLACE THIS AFTERNOON WHICH WILL LIMIT THE SEVERE WEATHER POTENTIAL. HOWEVER...AN ISOLATED DAMAGING WIND GUST COULD OCCUR AS THE STRONGER CELLS MATURE LATE THIS AFTERNOON. ..BROYLES/TAYLOR.. 08/12/2003 ...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. $$ |