000 FXUS64 KLUB 271122 AFDLUB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 522 AM CST FRI NOV 27 2009 .AVIATION... VFR CONDITIONS EXPECTED THROUGHOUT THE TAF PERIOD. SOUTHWESTERLY WINDS WILL BECOME SLIGHTLY BREEZY THIS AFTERNOON DUE TO A SURFACE LOW PRESSURE SYSTEM NEAR THE SOUTH PLAINS. FORECAST MODELS HINT AT A MOISTENING IN THE LOWER LEVELS...POSSIBLY INDUCING FOG/HAZE AT BOTH TAF SITES. HAVE KEPT THE MENTION OUT AT THIS TIME DUE TO UNCERTAINTY...AND WILL AMEND AS NECESSARY. && .PREV DISCUSSION... /ISSUED 417 AM CST FRI NOV 27 2009/ SHORT TERM... MAIN SYNOPTIC FEATURE FOR THE SHORT TERM FORECAST CONTINUES TO BE THE UPPER SHORTWAVE TROUGH...LOCATED ACROSS THE BAJA OF CALIFORNIA/WESTERN MEXICO. THE UA DISTURBANCE WILL CONTINUE TO TRANSLATE EAST ACROSS MEXICO...NEARING FAR WEST TEXAS DURING THE AFTERNOON HOURS. THERE IS A BIT OF DISCREPANCY AMONGST GUIDANCE MODELS REGARDING THE TEMPORAL EXTENT OF THE AFOREMENTIONED SHORTWAVE...AS THE GFS AND ECMWF ARE THE QUICKEST /NEARING THE CWA THIS EVENING/ VERSUS THE SLOWER NAM SOLUTION /ACROSS FAR SOUTHWEST TEXAS DURING THE SAME TIME PERIOD/. WILL SIDE WITH THE CONSENSUS WHICH WILL CONTINUE TO STREAM HIGH CLOUD DECKS ACROSS THE CWA...AND IT WILL INDUCE A TIGHTENED PRESSURE GRADIENT WHICH WILL INCREASE THE SOUTHWESTERLY SFC WINDS. THUS...THIS DOWNSLOPE COMPONENT /AND INCREASING MID TO HIGH LEVEL THICKNESS VALUES/ WILL WARM TEMPS WELL ABOVE SEASONAL NORMS AS THE UPPER RIDGE SLIDES EAST. ADDITIONALLY...THIS DRYING AFFECT COULD PROMOTE CONCERNS FOR FIRE WEATHER POTENTIAL...HOWEVER WINDS SHOULD REMAIN BELOW CRITICAL LEVELS. EARLY SATURDAY MORNING...WINDS ALOFT WILL SHIFT TO A MORE SOUTHWESTERLY COMPONENT AS A CUTOFF LOW DIVES SOUTHEAST ACROSS CENTRAL CALIFORNIA. SFC WINDS SHOULD BE AROUND 8 TO 10 KNOTS OVER NIGHT TONIGHT...LIKELY KEEPING TEMPS ABOVE FREEZING LEVELS ACROSS MOST LOCATIONS. LONG TERM... ALBEIT GRADUAL...CONFIDENCE HAS INCREASED WITH RESPECT TO THE SPLITTING TROF CURRENTLY AFFECTING THE PACIFIC NORTHWEST. BY SATURDAY MORNING...BASE OF SAID TROF SHOULD CLOSE OFF A MID- LEVEL LOW OVER SOCAL ALLOWING A DEEPER AND MORE MOIST SWLY FLOW TO OVERSPREAD WEST TX. MOST FAVORABLE FORCING SHOULD UNFOLD BY SUNDAY MORNING AS BOTH A COLD FRONT AND AN UPPER JET/S RRQ OCCUPY THE CWA. IN LIGHT OF THIS...POPS WERE TRENDED HIGHER AREA WIDE. PRECIPITATION TYPE NOW APPEARS TO BE PREDOMINANTLY RAIN FOR THIS EVENT BEFORE MIXING WITH SNOW SUN EVENING AND OVERNIGHT AS THICKNESSES GRADUALLY LOWER. WILL CONTINUE TO HIGHLIGHT POTENTIAL FOR SOME MINOR SNOW ACCUMULATIONS ACROSS OUR WESTERN ZONES IN THE SPS AND HWO. PROGRESSIVE NATURE TO THE NORTHERN STREAM TROF SHOULD BRING ABOUT DRIER CONDITIONS BY MONDAY WHILE THE UPPER LOW REMAINS POISED IN NORTHERN MEXICO. RATHER GOOD AGREEMENT IS NOW IN PLACE AMONG THE ENSEMBLES AND OPERATIONAL RUNS IN LIFTING THIS LOW EAST ACROSS THE BIG BEND BY WEDNESDAY. THIS TRACK WOULD STILL BE SUPPORTIVE OF LOW END POPS ACROSS OUR SOUTHERNMOST ZONES...HOWEVER THE FILLING NATURE OF THE SYSTEM BY THIS TIME SHOULD KEEP WINTRY PRECIPITATION VERY LIMITED. BEYOND THIS TIME...SIGNALS STILL POINT TO THE DEVELOPMENT OF A SHARP PACIFIC COAST RIDGE. ALTHOUGH ECMWF AND GFS DIFFER ON THE EXTENT OF THE NORTHERLY FLOW DOWNSTREAM OF THIS RIDGE...HAVE SIDED WITH THE COLDER SOLUTIONS SHOWN BY THE MORE CONSISTENT CMC AND ECMWF. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 68 32 70 33 43 / 0 0 0 30 40 TULIA 70 36 72 34 44 / 0 0 0 20 40 PLAINVIEW 70 38 74 36 45 / 0 0 0 20 40 LEVELLAND 70 37 73 40 47 / 0 0 0 20 40 LUBBOCK 71 39 76 40 47 / 0 0 0 20 40 DENVER CITY 69 37 73 42 51 / 0 0 0 20 40 BROWNFIELD 70 37 75 41 50 / 0 0 0 20 40 CHILDRESS 74 40 76 40 50 / 0 0 0 10 40 SPUR 72 37 76 41 52 / 0 0 0 10 40 ASPERMONT 72 44 76 44 53 / 0 0 0 10 40 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 29