193 FXUS64 KLUB 180459 AFDLUB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 1159 PM CDT FRI MAY 17 2013 .UPDATE... QUICK UPDATE TO ADD ISOLATED THUNDERSTORMS OVERNIGHT WITH DISTURBANCE SLOWLY PASSING OVERHEAD. RMCQUEEN && .AVIATION... STRONG WINDS WILL CONTINUE TO DEVELOP JUST OFF THE DECK EARLY SATURDAY MORNING WHICH WILL CREATE BREEZY WINDS AT THE SURFACE AT KLBB. FOG AND LOW CIG DEVELOPMENT IS ALSO IN DOUBT AT KCDS BUT A SLIGHT CHANCE AT LIGHT VSBY RESTRICTIONS STILL EXIST. SOUTH TO SOUTHWEST WINDS WILL INCREASE LATE SATURDAY MORNING IN RESPONSE TO A DEEPENING SURFACE PRESSURE TROUGH. && .PREV DISCUSSION... /ISSUED 706 PM CDT FRI MAY 17 2013/ AVIATION... FOG AND LOW CIGS ARE NOT ANTICIPATED TO BE AS EXTENSIVE AS FRIDAY MORNING WITH A STRONG LOW LEVEL JET FORMING JUST OFF THE SURFACE THIS EVENING. THIS WILL KEEP WINDS ELEVATED AT KLBB. THE LOW LEVEL JET MAY ALSO KEEP LOWERED VSBYS AND CIGS FROM AFFECTING THE KCDS TERMINAL. PREV DISCUSSION... /ISSUED 328 PM CDT FRI MAY 17 2013/ SHORT TERM... THE HEAT IS ON...WITH 1930Z TEMPERATURES IN THE MIDDLE AND UPPER 90S ACROSS THE CAPROCK WITH EVEN A FEW TRIPLE DIGITS NOTED ACROSS THE SOUTHERN ROLLING PLAINS. SOMEWHAT COOLER AIR WAS IN PLACE ACROSS THE FAR NORTHEAST ZONES WHERE BACKED FLOW...IMPROVED MOISTURE AND THE LATE CLEARING OF THE STRATUS HAVE KEPT TEMPERATURES IN THE 80S TO THIS POINT. AS OF THIS WRITING...RADAR WAS SHOWING THE DRYLINE NEARLY STATIONARY AND POSITIONED FROM NEAR WAYSIDE TO MCADOO TO DICKENS...THEN BENDING MORE EASTWARD. UP TO THIS POINT ONLY A VERY LIMITED CUMULUS FIELD WAS SEEN LOCALLY ALONG THE DRYLINE /IN FLOYD COUNTY/...WITH MORE ROBUST DEVELOPMENT NOTED ALONG THE DRYLINE NEAR KBKD THEN SOUTH-SOUTHWESTWARD TO NEAR KBBD. LATEST HIGH-RESOLUTION GUIDANCE CONTINUES TO FAVOR THE LATTER AREA FOR ROBUST SCATTERED CONVECTION LATE THIS AFTERNOON...WHILE CAP WILL LIKELY HOLD FIRM LOCALLY. OBVIOUSLY...IF DEEP MOIST CONVECTION CAN GET GOING HERE...STRONG INSTABILITY AND MODEST 0-6 KM SHEAR WOULD SUPPORT A SEVERE THREAT...THOUGH PROSPECTS FOR CI ARE HIGHLY CONDITIONAL. THE DRYLINE WILL RETREAT WESTWARD TONIGHT BUT WILL ALSO INTERACT WITH A STRENGTHENING SOUTHERLY LLJ DEVELOPING IN ADVANCE OF AN APPROACHING WESTERN TROUGH. THIS WILL TEND TO LIMIT THE BEST MOISTURE FLUX TO THE FAR NORTHEASTERN ZONES WHERE ANOTHER SHORTER BOUT OF LOW CLOUDS AND FOG WILL BE POSSIBLE EARLY SATURDAY. IN ADDITION...AN UPPER DISTURBANCE WILL LIFT FROM FAR NORTHERN MEXICO AND ACROSS THE CAPROCK LATE TONIGHT. SEVERAL NWP MODELS DO INDICATE LIGHT QPF ACROSS THE WESTERN ZONES LATE TONIGHT AS LIFT WITH THIS WAVE MOVES ACROSS. HOWEVER...IT WILL BE QUITE DRY IN THE DEEP SUB-CLOUD LAYER SO CHANCES FOR MEASURABLE PRECIPITATION FROM ANY ELEVATED SHOWERS WILL BE TOUGH TO COME BY. THE WESTERN TROUGH WILL DRAW CLOSER ON SATURDAY RESULTING IN HEIGHT AND PRESSURE FALLS AND A TIGHTENING SFC PRESSURE GRADIENT. THIS WILL MEAN INCREASINGLY BREEZY CONDITIONS...WITH THE DRYLINE PROGGED TO SHARPEN SOMEWHERE IN THE ROLLING PLAINS BY MID TO LATE AFTERNOON. IT APPEARS THE LARGE SCALE SUPPORT MAY BE A BIT DELAYED...AND RELATIVELY WARM TEMPERATURES ALOFT WILL TEND TO LIMIT CONVECTIVE CHANCES...BUT ENOUGH FORCING ALONG THE DRYLINE WILL BE PRESENT TO PROVIDE AT LEAST A SLIGHT CHANCE OF STORMS BY LATE IN THE AFTERNOON. MODEST INSTABILITY AND SHEAR COULD SUPPORT ISOLATED STRONG/SEVERE HIGH-BASED CONVECTION. WEST OF THE DRYLINE...GUSTY SOUTHWESTERLY WINDS WILL CREATE ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS. LOWS TONIGHT WILL BE MILD...ESPECIALLY ACROSS THE EASTERN HALF OF THE FA WHERE BETTER MOISTURE LEVELS WILL RESIDE WITH BREEZY LATE NIGHT WINDS. ACROSS THE NORTHWEST ZONES...LIGHTER WINDS AND LESS MOISTURE SHOULD ALLOW TEMPERATURES TO DROP NICELY INTO THE UPPER 50S AND LOWER 60S...WHILE LOWS OUT EAST WILL BE IN THE UPPER 60S AND LOWER 70S. HIGHS SATURDAY WILL AGAIN BE TOASTY...RANGING FROM THE MIDDLE 90S ACROSS THE SOUTHWEST PANHANDLE TO AROUND OR JUST ABOVE 100 DEGREES OFF THE CAPROCK. LONG TERM... EARLY TO MIDWEEK UPPER PATTERN TO SEE A TROUGH OVER THE NRN AND CNTL PLAINS MOVE SLOWLY EWD TO THE MS VALLEY WITH FLAT TO WEAKLY CYCLONIC FLOW OVER THE SRN HIGH PLAINS. UNFORTUNATELY THAT PATTERN THIS TIME OF YEAR SHOULD SHIFT THE DRYLINE TO THE EAST OF THE FCST AREA SUNDAY AND MONDAY WITH POTENTIAL FOR A WEAK FRONTAL BOUNDARY TO MOVE INTO THE AREA SUNDAY NIGHT BEFORE RETREATING MONDAY. STRONGER FRONTAL PASSAGE WILL COME TUESDAY AS THE LAST BIT OF ENERGY ASSOCIATED WITH AFOREMENTIONED TROUGH SHIFTS EWD WITH THE MAIN TROUGH. AFTER VERY WARM TEMPERATURES SUNDAY AND MONDAY THE FRONT WILL BRING SOME RELIEF WITH TEMPERATURES BRIEFLY NEAR NORMAL VALUES. THE LATTER HALF OF THE WEEK WILL SEE AN AMPLIFICATION OF THE UPPER PATTERN WITH A RIDGE BUILDING OVER THE PLAINS AND A LONG WAVE TROUGH DEVELOPING ALONG THE WEST COAST. THIS LATTER FEATURE APPEARS TO BE FURTHER TO THE WEST WITH EACH MODEL RUN...SO IN THE END THE UPPER RIDGE MAY WIN OUT FOR THURSDAY AND FRIDAY. HOWEVER...STILL SOME PRECIP SIGNAL SHOWING IN THE 12Z RUNS WITH POTENTIAL FOR THE FCST AREA TO BE JUST ON THE CYCLONIC SIDE OF THE UPPER RIDGE. FURTHERMORE THE NEAR-MERIDIONAL NATURE OF THE UPPER TROUGH WOULD SUPPORT DRAWING LOW LEVEL MOISTURE FARTHER WWD AND POTENTIAL FOR THE DRYLINE TO STAY FARTHER WEST EACH DAY...POSSIBLY AS FAR BACK AS THE NM STATE LINE. AS A RESULT...ALTHOUGH STILL RATHER UNCERTAIN REGARDING PRECIP POTENTIAL AS A WHOLE PATTERN SUGGESTS BRINGING SLIGHT CHANCE MENTION FOR BOTH THURSDAY AND FRIDAY BACK TO THE WEST. FIRE WEATHER... WEST OF THE DRYLINE...GUSTY SOUTHWESTERLY WINDS WILL CREATE ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS SATURDAY AFTERNOON AND EARLY EVENING. TEMPERATURES WILL CLIMB WELL INTO THE 90S PUSHING RH VALUES DOWN TOWARD 5 PERCENT. ONLY QUESTION MARK WILL BE THE WINDS WHICH WILL LIKELY RESIDE AROUND THE LOW END OF RED FLAG CRITERIA. THUS...WILL MAINTAIN THE FIRE WEATHER WATCH IN PLACE FOR TOMORROW AFTN/EVNG AND LET THE OVERNIGHT SHIFT MAKE A FINAL CALL ON WHETHER TO UPGRADE TO A RED FLAG WARNING OR A FIRE DANGER STATEMENT. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 58 93 55 89 53 / 20 0 0 0 0 TULIA 61 95 56 91 52 / 20 10 0 0 0 PLAINVIEW 61 96 56 93 53 / 20 10 0 0 0 LEVELLAND 62 97 58 93 56 / 20 0 0 0 0 LUBBOCK 65 98 58 95 57 / 20 10 0 0 0 DENVER CITY 62 95 59 93 58 / 20 0 0 0 0 BROWNFIELD 62 98 59 95 59 / 20 0 0 0 0 CHILDRESS 68 100 61 98 61 / 10 20 10 0 10 SPUR 66 102 58 99 61 / 10 10 10 0 0 ASPERMONT 72 101 69 101 64 / 10 20 20 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR THE FOLLOWING ZONES: TXZ021>024-027>030-033>036-039>042. && $$ 05/99