202 FXUS64 KLUB 221750 AFDLUB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 1250 PM CDT WED MAY 22 2013 .AVIATION... VFR CONDITIONS WILL CONTINUE FOR NEXT 24 HOURS WITH MAINLY S-SE SURFACE WINDS. THE LOW-LEVEL JET WILL INCREASE TO AROUND 40 KTS TONIGHT. HOWEVER...SFC WINDS SHOULD REMAIN ELEVATED AND PREVENT LOW-LVL WIND SHEAR MENTION IN TAF. THERE IS ALSO A VERY LOW PROBABILITY OF TSRA IN THE VICINITY OF KCDS AROUND THE 10 UTC TO 15 UTC TIME FRAME. && .PREV DISCUSSION... /ISSUED 644 AM CDT WED MAY 22 2013/ AVIATION... VFR EXPECTED WITH SLOWLY BUILDING RIDGE ALOFT...MODERATE SURFACE LOW PRESSURE TROUGH...AND LOW LEVEL SOUTHERLY FLOW. RMCQUEEN PREV DISCUSSION... /ISSUED 453 AM CDT WED MAY 22 2013/ SHORT TERM... UPPER LEVEL HEIGHTS WILL BUILD ACROSS THE AREA TODAY IN ADVANCE OF A WEAK DISTURBANCE PULLING ACROSS THE CENTRAL ROCKIES. THIS WAVE WILL ATTEMPT TO BREECH THE RIDGE ACROSS THE SOUTHERN PLAINS THIS EVENING BUT SHOULD ENCOUNTER SUBSTANTIAL RESISTANCE TO THUNDERSTORM DEVELOPMENT. THE MOST RECENT WRF/NAM SOLUTION HAS COME MUCH MORE INTO LINE WITH THE GFS BUILDING A SUBSIDENCE CAPPING INVERSION BETWEEN ABOUT 500 MB AND 600 MB LATE THIS AFTERNOON INTO THE EVENING. AS THE WAVE PULLS THROUGH DURING THE EVENING WITH A 55KT JET MAXIMUM AT H300 MB ACROSS THE AREA...A LOW LEVEL JET ALSO WILL START TO DEVELOP ASSISTING IN PULLING MUCH BETTER MOISTURE AND INSTABILITY NORTHWARD INTO EASTERN ZONES. HOWEVER GIVEN THE TREND TOWARDS MORE CAPPING WE WILL RETAIN THE PREVIOUS DRY FORECAST THROUGH TONIGHT. SIGNALS OF A POSSIBLE MCS DEVELOPING FROM NORTHWEST OKLAHOMA SOUTHEASTWARD ARE STILL APPARENT VERY LATE TONIGHT...THOUGH REMAIN JUST OUT OF OUR AREA. STILL...THIS MAY LEAD TO AN OUTFLOW BOUNDARY OR AN INCREASE IN EAST OR SOUTHEAST WINDS FROM WESTERN OKLAHOMA WESTWARD LATE TONIGHT OR EARLY THURSDAY. LITTLE DISAGREEMENT WITH THE PREVIOUS TEMPERATURES AS WELL. RMCQUEEN LONG TERM... PROSPECTS CONTINUE TO BE LIKELY FOR SEVERE CONVECTION TO IMPACT THE EXTREME SOUTHERN TEXAS PANHANDLE...SOUTH PLAINS...AND ROLLING PLAINS THURSDAY AFTERNOON AND EVENING. MID TO UPPER RIDGING WILL AMPLIFY OVER THE HEART OF THE COUNTRY...EXTENDING FROM THE SOUTHERN PLAINS INTO CANADA. INCREASING MOISTURE WILL BE IN PLACE OWING TO THE PREVIOUS NIGHT/S LOW LEVEL JET USHERING RICHER GULF MOISTURE INTO THE AREA AS EVIDENCED BY DEWPOINTS CLIMBING INTO THE UPPER 50S TO LOWER 60S AHEAD OF THE DRYLINE...WHICH IS PROGGED TO MIX EAST SOMEWHERE IN VICINITY OF THE EDGE OF THE CAPROCK DURING PEAK HEATING. A BACKDOOR FRONT WILL APPROACH FROM THE CENTRAL/SOUTHERN GREAT PLAINS DURING THE AFTERNOON...CREATING INCREASED LOW LEVEL CONVERGENCE AND HELICITY ALONG THE DRYLINE/FRONT INTERFACE. INSTABILITY WILL BE PLENTIFUL AHEAD OF THE DRYLINE AND LOOKS TO BE FURTHER ENHANCED BY A SHORTWAVE TROUGH MOVING THROUGH THE RIDGE AND COOLING TEMPERATURES ALOFT. THE TIMING OF THIS PERTURBATION WILL HAVE AN IMPACT ON SYNOPTIC FORCING FOR ASCENT...PERHAPS COUPLING WITH THE RIGHT ENTRANCE REGION OF A STRENGTHENING SUBTROPICAL JET. LOW LEVEL SPEED SHEAR WILL RECEIVE A BOOST HEADING INTO THE EVENING AS A 30-40 KNOT LOW LEVEL JET DEVELOPS AND LENGTHENS ALREADY CURVED HODOGRAPHS. BELIEVE INITIATION WILL TAKE PLACE ACROSS THE EXTREME SOUTHERN PANHANDLE INTO THE ADJACENT ROLLING PLAINS WHERE THE DRYLINE AND BACKDOOR FRONT MEET BY MID AFTERNOON...BEFORE MOVING SOUTHWEST IN CONJUNCTION WITH THE FRONT AND RETREATING DRYLINE INTO THE EVENING. LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THREATS AREAWIDE...WHILE A CONDITIONAL TORNADO THREAT WILL EXIST BASED ON WHERE HELICITY/DIRECTIONAL SHEAR ARE ENHANCED DUE TO BACKED WINDS ALONG THE FRONT. PRECIPITABLE WATER VALUES IN THE INCH TO INCH AND A HALF RANGE WILL ALSO PROMOTE LOCALLY HEAVY DOWNPOURS. DRYLINE WILL CONTINUE RETREATING FRIDAY BY ENTERING NEW MEXICO THANKS TO SOUTHEASTERLY LOW LEVEL FLOW ON THE BACKSIDE OF SURFACE HIGH PRESSURE ACROSS THE EASTERN HALF OF THE COUNTRY AND LEE TROUGHING NEAR THE FRONT RANGE. THIS WILL FAVOR WESTERN ZONES IN TERMS OF THUNDERSTORM DEVELOPMENT FRIDAY INTO THE WEEKEND AS THE DRYLINE PROVIDES THE FOCUS FOR INITIATION. AN UPPER LOW/TROUGH WILL BEGIN TO MIGRATE OFF THE PACIFIC COAST INTO EARLY NEXT WEEK ALLOWING THE DRYLINE TO BEGIN MIXING FARTHER EAST INTO THE SOUTH/ROLLING PLAINS. WILL MAINTAIN A DRY FORECAST AFTER SUNDAY AS PROGRESSION OF THIS SYSTEM AND DRYLINE PLACEMENT WILL DICTATE STORM CHANCES. TEMPERATURES WILL HOLD NEAR NORMAL...GENERALLY RANGING IN THE MID 80S TO MID 90S FOR HIGHS WITH LOWS IN THE UPPER 50S TO MID 60S UNDERNEATH A SOUTHWESTERLY FLOW REGIME. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 87 57 86 59 82 / 0 10 20 30 30 TULIA 88 59 86 62 83 / 0 10 40 40 20 PLAINVIEW 89 61 87 64 84 / 0 10 30 40 20 LEVELLAND 90 63 89 64 84 / 0 10 20 30 20 LUBBOCK 90 65 90 66 86 / 0 10 20 40 20 DENVER CITY 90 64 93 65 85 / 0 10 20 20 20 BROWNFIELD 92 65 90 65 86 / 0 10 20 30 20 CHILDRESS 91 63 88 65 85 / 10 10 60 60 20 SPUR 91 63 90 67 88 / 10 10 30 50 20 ASPERMONT 93 67 92 69 91 / 10 10 20 40 20 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 33