000 FXUS64 KLUB 091647 AAA AFDLUB AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE LUBBOCK TX 1047 AM CST THU FEB 9 2012 .DISCUSSION... BASED ON CURRENT OBS/TRENDS...HAVE ADJUSTED POPS UP ACROSS THE NORTHERN AND FAR NORTHWESTERN ZONES LATE THIS MORNING. SOME LIGHT SHOWERS WILL CONTINUE TO SPREAD ACROSS THE AREA FROM NEW MEXICO AHEAD OF A FAST MOVING UPPER-TROUGH THAT IS PUSHING THROUGH THE SOUTH CENTRAL ROCKIES LATE THIS MORNING. WITH TOP-DOWN MOISTENING OCCURRING SOME LIGHT PRECIPITATION IS REACHING THE GROUND ACROSS THE FAR NORTHWESTERN ZONES. THIS TREND IS EXPECTED TO TRANSLATE SOUTH AND EASTWARD OVER THE COURSE OF THE AFTERNOON AND EVENING WITH THE PASSAGE OF THE AFOREMENTIONED UPPER-TROUGH AND ITS ASSOCIATED COLD FRONT. BEHIND THE FRONT IN THE PANHANDLE /WHERE SOME COLDER SUBFREEZING AIR IS PRESENT AT THE SURFACE/...SOME LIGHT ICING HAS CAUSED SOME TRAVEL ISSUES ON ROADWAYS. HOWEVER... TEMPERATURES ACROSS THE SOUTHERN PANHANDLE AND POINTS SOUTH REMAIN IN THE UPPER 30S TO MID 40S AS OF 16Z. THOUGH SOME WET-BULB COOLING FROM A PASSING SHOWER COULD DROP TEMPERATURES AROUND THE FREEZING MARK IN LOCALIZED AREAS...ANY LIGHT SNOW THAT MAY MIX IN WILL BE SHORT-LIVED AND SHOULD MELT ON IMPACT GIVEN THE WARMER SURFACE TEMPERATURES THIS MORNING. AS THE TROUGH SWINGS SOUTH AND EAST OF THE REGION BY THIS EVENING...ANY LIGHT SHOWERS WILL WANE IN OUR FAR SOUTHEASTERN ZONES BETWEEN 00-06Z OR SO. && .PREV DISCUSSION... /ISSUED 526 AM CST THU FEB 9 2012/ AVIATION... UPPER TROUGH MOVING ACROSS SRN ROCKIES THIS MORNING AND WILL BRING LOWERING CLOUDS THROUGH THE DAY WITH A CHANCE FOR SOME LIGHT SHOWERS LATE IN THE DAY INTO EARLY EVENING. MVFR CIGS POSSIBLE WITH THOSE SHOWERS BUT THEN SHOULD LIFT TOWARD 06Z. COLD FRONT TO MOVE THROUGH WITH THE UPPER TROUGH BTWN 18Z AND 00Z. PREV DISCUSSION... /ISSUED 400 AM CST THU FEB 9 2012/ SHORT TERM... A CLOSED UPPER LOW WILL REMAIN WELL SW OF THE FCST AREA OFF THE COAST OF BAJA CALIF TODAY AND TONIGHT. THE MORE IMPORTANT FEATURE FOR NW TEXAS WILL BE A FAST MOVING UPPER TROUGH THAT AT 08Z THIS MORNING WAS SWEEPING ACROSS THE 4-CORNERS REGION. TOP-DOWN MOISTENING WITH THE LIFT AHEAD OF THIS SYSTEM WILL GRADUALLY SEE CLOUD DECK LOWER WITH SOME SHOWER ACTIVITY POSSIBLE IN THE NWRN ZONES BY 18Z THEN ACROSS THE CENTRAL ZONES THIS AFTERNOON BEFORE EXITING ACROSS THE ERN THIRD OF THE FCST AREA THIS EVENING. FAST MOVING NATURE OF THIS SYSTEM WILL LIMIT AVAILABLE MOISTURE AND THUS IS EXPECTED TO KEEP PRECIP LIGHT. HOWEVER...IT DOES LOOK LIKE A GOOD ALBEIT NARROW WINDOW FOR PRECIP. HAVE INCREASED POPS NEAR THOSE OF MET MOS AND ALSO MOVED POPS FORWARD ABOUT SIX HOURS BASED ON FASTER MOVEMENT OF THIS SYSTEM THAN PREVIOUSLY ANTICIPATED. WITH INCREASING CLOUD COVER TODAY HAVE FAVORED COOLER MAV MOS NUMBERS FOR HIGHS TODAY. FASTER EGRESS OF THE TROUGH TONIGHT AND DRYING BEHIND IT SUGGEST COOLER TREND FOR OVERNIGHT LOWS PER MOS GUIDANCE LIKELY THE CORRECT DIRECTION. LONG TERM... PATTERN CHANGE FOR THE BETTER REMAINS ON THE HORIZON AS DEPRESSED HEIGHT ANOMALIES BECOME MORE COMMON THROUGHOUT THE SWRN CONUS. ELSEWHERE...DEEP MERIDIONAL FLOW ON THE BACK SIDE OF A POLAR VORTEX NEAR THE HUDSON BAY IS ALREADY IN THE PROCESS OF RELEASING ARCTIC AIR INTO THE CANADIAN PRAIRIES. AN EXTENSION OF THIS MODIFYING AIRMASS IS STILL EXPECTED FOR ARRIVAL ON THE SOUTH PLAINS THIS SATURDAY. IN SPITE OF SERIOUS RUN-TO-RUN CONTINUITY ISSUES WITH THE GFS /E.G. 00Z RUN IS OVER 250 MILES FARTHER SOUTH WITH THE COLD FRONT BY 00Z SUN THAN YESTERDAY/S 12Z RUN/...WILL GIVE THE NOD TO THE FASTER ECMWF ESPECIALLY CONSIDERING THE SOURCE REGION OF THIS AIRMASS. ONLY COMFORT OFFERED BY THE GFS IS WITH ITS ENSEMBLE MEAN MOS GUIDANCE WHICH HAS NOW PLUMMETED SATURDAY/S HIGHS INTO THE UPPER 30S...WHICH SEEMS FULLY PLAUSIBLE GIVEN THE PATTERN AND A NET INCREASE IN POST-FRONTAL STRATUS THROUGH THE DAY. THE FIRST IN A SERIES OF SHORTWAVE TROUGHS WILL BE FOUND PASSING OVER THE COLORADO PLATEAU LATE IN WEEKEND BEFORE LIFTING EAST OF THE CWA ON MONDAY WHILE MINORING OUT. DID NOT ADJUST POPS MUCH AT ALL FROM BEFORE AS THE BRUNT OF THE WARM AIR ADVECTION AND HEIGHT FALLS STILL APPEAR TO UNFOLD DURING THE DAY SUNDAY. MOST PERTINENT QUESTION IS HOW MUCH MOISTURE AHEAD OF A CUTOFF LOW SOUTH OF OUR SHORTWAVE TROUGH CAN BE ADVECTED NORTHWARD? ECMWF IS SLIGHTLY MORE MERIDIONAL WITH THE MID-LEVEL FLOW THAN THE GFS AND AS A RESULT REMAINS THE MOST GENEROUS WITH QPF. OPEN AND PROGRESSIVE STRUCTURE OF THIS WAVE CERTAINLY LEAVES SOMETHING TO BE DESIRED FOR A SIGNIFICANT PRECIP EVENT...BUT UNFORTUNATELY THIS STORM MAY BE REMEMBERED FOR ITS WINTRY PRECIP MODE RATHER THAN HOW MUCH PRECIP IS MEASURED IN THE END. WITH ABUNDANT MOISTURE ADVECTION/STRATUS SAT NIGHT THROUGH SUNDAY...THE DIURNAL TEMP CURVE SHOULD BE NARROWED TO ONLY A HANDFUL OF DEGREES IN MOST PLACES. WHILE STILL THREE DAYS OUT...THERMODYNAMIC PROFILES REMAIN SUPPORTIVE OF FROZEN PRECIP INITIALLY SUN MORNING /PERHAPS ALL SNOW/ UNTIL A CHANGEOVER ENSUES FROM SOUTH-TO-NORTH WITH PELLETS/FZRA/AND ALL RAIN IN SOME AREAS AS AN ELEVATED WARM NOSE STRUCTURE EVOLVES. IF THE COLD SURFACE HIGH WAS NOT LOCATED SO FAR TO OUR NORTHEAST BY SUN MORNING THEN THIS CHANGEOVER TO RAIN WOULD BE IN JEOPARDY. BUT AS IT STANDS NOW STOUT SOUTHERLY FLOW FROM 850-700MB SHOULD DEEPEN AND EVENTUALLY OVERWHELM THE SHALLOW COLD AIRMASS. CONFIDENCE IN POPS IS STILL BELOW 50 PERCENT...SO WILL CONTINUE TO HIGHLIGHT THIS WINTRY THREAT IN THE HWO. ROBUST WESTERLY FLOW IN THE WAKE OF SUNDAY/S TROUGH COULD MAKE FOR A WINDY/DUSTY AND VERY MILD MONDAY IF THE GFS IS CORRECT...ALTHOUGH THE ECMWF IS MUCH STRONGER WITH S/W RIDGING AT THIS TIME AND CONSEQUENTLY WEAKER WITH WINDS AND A BIT COOLER WITH TEMPS. ALSO...ANY AMOUNT OF SNOW/ICE ACCUMULATIONS COULD HIJACK MILD TEMPS. NEXT TROUGH /POTENTIALLY FAR MORE VIGOROUS/ IS SCHEDULED TO ARRIVE WED OR THU...BUT WOULD STILL PREFER TO SEE BETTER NWP AGREEMENT SURROUNDING THIS WAVE/S TIMING BEFORE INSERTING POPS IN ANY ONE PERIOD OR WORSE...BLANKETING A 48 HOUR WINDOW. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 41 25 53 25 41 / 60 10 0 0 10 TULIA 47 28 51 24 35 / 60 20 0 0 10 PLAINVIEW 51 28 52 25 36 / 60 20 0 0 10 LEVELLAND 52 30 54 28 43 / 50 20 0 0 10 LUBBOCK 53 31 54 27 39 / 50 20 0 0 10 DENVER CITY 51 32 55 29 53 / 30 30 0 0 10 BROWNFIELD 51 31 55 29 48 / 40 30 0 0 10 CHILDRESS 50 34 54 25 36 / 50 60 10 0 10 SPUR 54 34 56 28 40 / 40 50 10 0 10 ASPERMONT 59 39 57 29 44 / 20 50 10 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 22