000
FXUS64 KLUB 181744
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
1244 PM CDT SAT MAY 18 2013

.AVIATION...
EXPECT VFR CONDITIONS TO REMAIN AT THE TERMINALS THIS TAF
CYCLE...WITH BREEZY SOUTH TO SOUTHWESTERLY WINDS THIS AFTERNOON
AND BREEZY WESTERLY WINDS TOMORROW AFTERNOON. KCDS WILL HAVE AN
OUTSIDE CHANCE OF A STORM LATE THIS AFTERNOON INTO EARLY THIS
EVENING...BUT PROSPECTS OF A DIRECT IMPACT ARE TOO LOW TO INCLUDE
IN THE TAF ATTM.

&&

.PREV DISCUSSION... /ISSUED 1131 AM CDT SAT MAY 18 2013/

UPDATE...
SHORTWAVE TROUGH THAT BROUGHT THE EXCITEMENT IN TERMS OF
HEAT BURSTS...SPOTTY LIGHT RAIN AND A FEW ELEVATED STORMS WAS NOW
EXITING TO OUR NORTHEAST...WITH THE NEXT UA TROUGH OF CONSEQUENCE
APPROACHING THROUGH THE DESERT SOUTHWEST. LIFT WITH THE WESTERN
NEGATIVELY TILTED TROUGH WAS INCREASING ACROSS MUCH OF NM AND WILL
CONTINUE TO SPREAD EASTWARD THIS AFTERNOON AND TONIGHT. THIS WILL
PROVIDE AT LEAST SOME UPPER LEVEL SUPPORT BY PEAK HEATING WITH THE
GREATEST UPPER FORCING PROGGED TO MOVE ACROSS LATE TONIGHT. AT THE
SFC...SOUTHERLY FLOW HAS DRAWN DEWPOINTS INTO THE LOWER AND MIDDLE
60S ACROSS THE EASTERN ZONES...THOUGH VEERING FLOW WAS ALSO
BRINGING IN MUCH DRIER AIR ACROSS THE WESTERN ZONES. IN
FACT...HUMIDITIES WERE ALREADY BELOW 10 PERCENT ACROSS THE FAR
NORTHWEST ZONES...WHERE COUPLED WITH INCREASING WINDS...THE FIRE
DANGER WILL BE HIGH. IT STILL APPEARS THE DRYLINE WILL SHARPEN
SOMEWHERE IN CLOSE PROXIMITY TO OUR EASTERN MOST ZONES BY MID TO
LATE AFTERNOON. STRONG HEATING/MIXING...WITH HIGHS CLIMBING UP
INTO THE TRIPLE DIGITS...COUPLED WITH CONVERGENCE ALONG THE
DRYLINE AND WEAK UPPER SUPPORT SHOULD BE ENOUGH TO BREAK THE
CAP...WITH ISOLATED TO WIDELY SCATTERED MOIST CONVECTION EXPECTED
TO DEVELOP AFTER 20Z. STRONG INSTABILITY EAST OF THE DRYLINE
COUPLED WITH SUFFICIENT DEEP LAYER SHEAR WILL ALLOW STORMS TO
RAPIDLY BECOME SEVERE...WITH SUPERCELLULAR MODES LIKELY.
RELATIVELY HIGH LCLS AND RATHER WEAK 0-1 KM SHEAR WOULD SUGGEST
LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE PRIMARY MODE WITH
THE INITIAL DEVELOPMENT...THOUGH STRONG INSTABILITY COULD
COMPENSATE SOMEWHAT AND PROVIDE A LOW TORNADO CHANCE. LOW-LEVEL
WIND SHEAR WILL INCREASE THIS EVENING AS THE LOWER WIND FIELDS
STRENGTHEN AND BACK AND LCLS GRADUALLY LOWER. BIGGEST QUESTION
FOR OUR CWA IS IF AND FOR HOW LONG CONVECTION CAN STAY IN OUR
AREA. OF THE GUIDANCE THAT DEVELOPS STORMS IN OUR EASTERN ZONES
LATE THIS AFTERNOON...MOST SHOW THE ACTIVITY QUICKLY SHIFTING EAST
OF THE FA...WHICH WOULD KEEP OUR WINDOW FOR SEVERE WEATHER QUITE
NARROW. THERE MAY BE A RISK FOR REDEVELOPMENT ALONG THE DRYLINE IN
OUR FAR EASTERN ZONES LATE TONIGHT AS THE LARGE SCALE SUPPORT
PEAKS...THOUGH MOST GUIDANCE DOES NOT SHOW THIS SCENARIO...WITH
THE COOLING LOWER ATMOSPHERE REMAINING CAPPED. WEST OF THE
DRYLINE...ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS WILL EXIST
AND THE RED FLAG WARNING AND FIRE DANGER STATEMENT REMAIN VALID
FOR THIS AFTERNOON AND EVENING. THE ONGOING FORECAST HAD A GOOD
HANDLE ON ALL OF THIS AND ONLY MINOR TWEAKS WERE MADE THIS MORNING.

PREV DISCUSSION... /ISSUED 517 AM CDT SAT MAY 18 2013/

SHORT TERM...
TWO BANDS OF VERY LIGHT VIRGA SHOWERS CONTINUE MOVING NORTHEAST
ACROSS THE FAR SOUTHEASTERN TEXAS PANHANDLE AND ROLLING PLAINS THIS
MORNING. THIS IS DUE TO A WEAK UPPER LEVEL DISTURBANCE MOVING
THROUGH ALONG WITH A LOW LEVEL JET INTERACTING WITH THE DRYLINE.
THIS SHOULD WRAP UP BY SUNRISE BEFORE THE MERCURY STARTS TO CLIMB
AGAIN. DEEP MIXING WILL OCCUR AS SKIES CLEAR FROM WEST TO EAST THIS
MORNING AND LEAD TO HIGHS IN THE MID 90S ACROSS THE NORTHWEST TO THE
LOW 100S INTO THE ROLLING PLAINS. CHILDRESS IS FORECAST TO HIT 101
DEGREES TODAY WHICH WOULD BREAK THE PREVIOUS RECORD OF 99 FOR THE
DATE.

AN UPPER TROUGH CURRENTLY ENTERING THE GULF OF CALIFORNIA WILL
CONTINUE TO SLIDE EAST TODAY AND INCREASE FORCING FOR ASCENT
ACROSS THE REGION AS HEIGHTS FALL. THE DRYLINE WILL MIX QUICKLY EAST
AHEAD OF THIS FEATURE...POSSIBLY MIXING EAST OF THE ROLLING PLAINS
THIS AFTERNOON. HOWEVER...A DEEPENING SURFACE LOW ACROSS THE
TEXAS/OKLAHOMA PANHANDLES SHOULD KEEP THE DRYLINE WITHIN REACH SO
THAT IT RETREATS BACK ACROSS THE ROLLING PLAINS AND EXTREME
SOUTHEAST PANHANDLE THIS EVENING.

DEEP LAYER SUPPORT WILL BE MAXIMIZED THIS EVENING AND EARLY TONIGHT
AS THE PREVIOUSLY MENTIONED NEGATIVELY TILTED TROUGH SWINGS INTO
SOUTH CENTRAL NEW MEXICO. AN INTENSIFYING LOW LEVEL JET WILL ALSO
DEVELOP AND USHER IN RICHER MOISTURE AHEAD OF THE
DRYLINE...LENGTHENING HODOGRAPHS AND STRENGTHENING SHEAR PROFILES TO
SUPPORT ORGANIZED UPDRAFTS. EVEN THOUGH COVERAGE MAY BE
LIMITED...BELIEVE WHAT DOES DEVELOP WILL BE STRONG TO
SEVERE...CAPABLE OF PRODUCING LARGE HAIL...GUSTY WINDS TO 60
MPH...AND AN ISOLATED TORNADO. STORM ROOTS WILL BECOME INCREASINGLY
ELEVATED AS SURFACE COOLING COMMENCES POST-SUNSET...LEADING TO MORE
OF A HAIL THREAT AS THE EVENING WEARS ON. CONDITIONS WILL DRY OUT
AFTER MIDNIGHT AS THE TROUGH AND SURFACE LOW PUSH EAST AND PULL
DRIER AIR ACROSS THE AREA.

LONG TERM...
AN ACTIVE WEATHER PATTERN IN STORE DURING THE NEXT WEEK WHICH SOME
EXCITEMENT INTO NEXT WEEKEND...MORE ON THAT LATER.

UPPER LEVEL LOW WILL BECOME ESTABLISHED FROM THE NEG TILTED TROUGH
ACROSS THE WESTERN USA.  THIS LOW WILL UNDERGO MATURATION LATE THIS
WEEKEND INTO EARLY NEXT WEEK ACROSS THE NORTH CENTRAL PLAINS WHILE A
LOBE OF ENERGY ROTATES AROUND THIS PARENT LOW REACHING THE FOUR
CORNERS BY MONDAY AFTERNOON.  BY LATE TUESDAY AFTERNOON...
NORTHWESTERLY FLOW RETURNS TO THE AREA AS ANOTHER DEEP LOW COMES
ASHORE THE PACIFIC NORTHWEST COAST.  RIDGING WILL BUILD INTO THE
CENTRAL CONUS SERVING TO BLOCK EWRD PROGRESSION OF NORTHWESTERN LOW.

ON SUNDAY MORNING...DRYLINE SHOULD START OFF ACROSS OUR EASTERN
ZONES THUS LEAVING THE AREA HOT AND DRY. IT WOULD APPEAR THAT
ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS WILL OCCUR ONCE AGAIN
ON SUNDAY AFTERNOON AS WIND SPEEDS RAMP UP TO THE 20 TO 25 MPH
RANGE. NWP IS STRONGER WITH THE LATE SUNDAY COLD FRONT THIS
MORNING AND GIVEN THE STRENGTH AND RESULTS OF THIS MORNINGS TROUGH
WHICH GENERATED SOME HIGH BASED SHOWER ACTIVITY...THIS NEW FOUND
STRENGTH APPEARS PLAUSIBLE. THE NAM IS MOST ASSERTIVE WITH THE
PROGRESSION OF THE FEATURE. WHICH BY IN LARGE MAY MAKE IT
MOST...BUT PERHAPS NOT ALL THE WAY ACROSS THE CWFA. SURFACE LOW
LOOKS TO REMAIN OVER THE EASTERN HALF OF THE AREA ON MONDAY
KEEPING THINGS QUITE WARM AND DRY. INTO THE EVENING HOURS...A MUCH
MORE PRONOUNCED COLD FRONT MAKES THROUGH WITH THE GFS DEPICTING
POST-FRONTAL PRECIPITATION. HOWEVER...THE MODEL APPEARS TOO MOIST
AND WILL CONTINUE THE FCST THINKING THAT THIS WILL YIELD YET
ANOTHER DRY FRONTAL PASSAGE THOUGH AREAS TO OUR NORTH AND EAST
WILL HAVE A BETTER CHANCE OF STORMS. FCST GUIDANCE HAS TRENDED
LOWER ON TUESDAY/S HIGH AND GIVEN THE EVOLUTION OF THE
SYSTEM...THIS TOO SEEMS REASONABLE AND ADJUST TEMPS COOLER TUE/WED
AS A RESULT. INTO LATE WEEK...MORE EXCITING PROSPECTS FOR
PRECIPITATION ARE LOOKING TO COME TOGETHER AS PERSISTENT SWRLY
FLOW ALOFT ALLOWS INCREASING MOISTURE INTO THE REGION THEN
ASSISTED BY A SLUG OF PACIFIC MOISTURE LATE THURSDAY. WITH PWAT
VALUES INCREASING UP TO WELL OVER AN INCH THIS LOOKS LIKE IT COULD
YIELD THE BEST PROMISE OF MEANINGFUL RAINFALL IN SOME TIME...AND
WE`LL TAKE WHAT WE CAN GET!

FIRE WEATHER...
DAY 1
CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP WEST OF AN EASTWARD
MIXING DRYLINE THIS AFTERNOON. THE PREVIOUSLY ADVERTISED FIRE
WEATHER WATCH HAS BEEN UPGRADED TO A RED FLAG WARNING ACROSS
WESTERN AND CENTRAL PORTIONS OF THE EXTREME SOUTHERN TEXAS
PANHANDLE...SOUTH PLAINS...AND FAR WESTERN ROLLING PLAINS.
TEMPERATURES WILL CLIMB INTO THE MID 90S TO NEAR 100 DEGREES WITH
MINIMUM RELATIVE HUMIDITIES IN THE SINGLE DIGITS. 20 FOOT WINDS
WILL INCREASE TO 20 MPH OR SLIGHTLY ABOVE THUS WARRANTING THE
UPGRADE TO A WARNING. WILL ISSUE A RANGELAND FIRE DANGER STATEMENT
FOR AREAS JUST EAST OF THOSE IN THE WARNING.

DAY 2-3
CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE ONCE AGAIN
SUNDAY AFTERNOON OVER MUCH OF THE SAME AREA COVERED BY THE WARNING
THIS MORNING AS DRY CONDITIONS COMBINE WITH BREEZY AFTERNOON
WINDS. TO AVOID PRODUCT CONFUSION...WILL HOLD OFF ON SECOND RED
FLAG PRODUCT FOR SUNDAY AT THIS TIME. WHILE FIRE WEATHER
CONDITIONS MAY EASE ON MONDAY TO SOME EXTENT...ELEVATED TO NEAR
CRITICAL CONDITIONS MAY OCCUR DURING THE AFTERNOON AS WELL.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        56  87  54  83  49 /   0   0   0   0   0
TULIA         57  92  56  88  52 /   0   0   0   0   0
PLAINVIEW     57  94  58  89  53 /   0   0   0   0   0
LEVELLAND     59  94  57  90  54 /   0   0   0   0   0
LUBBOCK       59  96  60  91  55 /   0   0   0   0   0
DENVER CITY   60  92  59  90  55 /   0   0   0   0   0
BROWNFIELD    60  95  60  92  55 /   0   0   0   0   0
CHILDRESS     63  95  62  92  58 /  20   0   0   0   0
SPUR          59  98  64  94  60 /  10   0   0   0   0
ASPERMONT     69  99  65  97  62 /  20   0   0   0   0

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>024-027>030-033>036-039>042.

&&

$$

23/99/99