Wildfire and High Wind in Texas, April 25, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
701 AM CDT MON APR 25 2011

.AVIATION...
QUASI-STATIONARY FRONT WAS SITTING RIGHT ON TOP OF KLBB THIS
MORNING...WITH LIGHT AND VARIABLE WINDS AND LIFR CONDITIONS IN LOW
CLOUDS/FOG JUST TO THE EAST OF THE BOUNDARY /LESS THAN 10 MILES
FROM KLBB/. THE LOW CLOUDS AND FOG COULD THREATEN KLBB THE NEXT
HOUR OR TWO...BUT WITH LITTLE MOVEMENT OF THE CIGS OVERNIGHT...THINK
THE POOR FLYING CONDITIONS SHOULD REMAIN JUST EAST OF THE TERMINAL
BEFORE RAPIDLY SCOURING EASTWARD THROUGH THE MORNING HOURS AS WESTERLY
WINDS INCREASE AND SPREAD MUCH DRIER AIR ACROSS THE SOUTH PLAINS.
WINDS WILL BECOME SUSTAINED AROUND 25-30 KTS AT KLBB BY THIS
AFTERNOON AND THIS MAY CAUSE MINOR RESTRICTIONS IN BLDU...BEFORE
THE WINDS DROP OFF THIS EVENING. WINDS MAY REQUIRE AN AWW BEFORE
ALL IS SAID AND DONE...BUT IT IS NOT CLEAR CUT AND WILL HOLD OFF
ON ISSUING FOR NOW. KCDS IS CURRENTLY ENVELOPED IN LOW CLOUDS AND
FOG...BUT LIFR CONDITIONS THERE SHOULD IMPROVE BY LATE
MORNING...WITH VFR TOWARD OR SHORTLY AFTER MIDDAY. WINDS WILL BE
TRICKY AT KCDS AS THE ADVANCING BOUNDARY WILL LIKELY STALL
SOMEWHERE NEARBY THIS AFTERNOON. THERE IS ALSO AN OUTSIDE SHOT
KCDS COULD SEE A HIGH BASED SH/TSRA LATE THIS AFTERNOON OR EARLY THIS
EVENING...BUT CONFIDENCE IN THIS IS LOW AND HAVE LEFT OUT OF THE
TAF. THE STALLED BOUNDARY WILL THEN REGAIN VIGOR TO THE SOUTH
TONIGHT...WITH A NORTH TO EAST WIND SHIFT AT THE TERMINALS AND LOW
CHANCES OF BR OR LOW CIGS DEVELOPING TOWARD TUESDAY MORNING.

&&

.PREV DISCUSSION... /ISSUED 421 AM CDT MON APR 25 2011/

SHORT TERM...
TODAY/S PRIMARY FORECAST CONCERNS REVOLVE AROUND WIND AND FIRE
WEATHER...THANKS TO A PASSING UPPER LEVEL STORM SYSTEM THAT WILL
RACE ACROSS THE AREA TODAY.

COMPLICATING THE FORECAST IS THE SEMI-PERMANENT FRONT THAT HAS BEEN
LINGERING IN THE REGION. THE QUASI-STATIONARY FRONT STRETCHED
ROUGHLY FROM FRIONA TO LUBBOCK TO TAHOKA AND THEN MORE EASTWARD BACK
INTO NORTH TEXAS AS OF 8Z. NORTH AND EAST OF THE FRONT LOW CLOUDS
AND AREAS OF FOG HAVE FILLED IN WHILE MOSTLY CLEAR SKIES AND DRY AIR
WAS POSITIONED ACROSS THE WESTERN SOUTH PLAINS INTO EASTERN NM. THE
FRONT HAS RETREATED SLOWLY WESTWARD OVERNIGHT...BUT WILL QUICKLY
REGAIN AN EASTWARD MOMENTUM AS INCREASING WESTERLY TROPOSPHERIC FLOW
SPREADS ACROSS THE AREA THROUGH THE BASE OF THE PASSING TROUGH.
EXPECT THE FRONT TO PUSH THROUGH MOST OF THE CWA...THOUGH IT WILL
LIKELY HANG UP NEAR OR ACROSS THE EXTREME NE ZONES /AROUND KCDS/ BY
MID TO LATE AFTERNOON...THEN PLUNGE BACK SOUTHWARD THROUGH THE CWA
TONIGHT. HOWEVER...BEFORE IT DOES SO...A 60+ KT 500 MB JET WILL
SWING ACROSS THE SOUTH PLAINS TODAY...AND WITH PROGGED SOUNDINGS
INDICATING MIXING TO NEAR 600 MB...AND 850-700 MB MEAN FLOW AROUND
30 KTS...THIS SHOULD GARNER A SWATH OF SUSTAINED SPEEDS OF 25-35 MPH
OVER MUCH OF THE CAPROCK. THE ONLY QUESTION MARK MAY BE ACROSS OUR
EXTREME NORTHERN ZONES...WHERE THE STRONGEST WIND FIELDS MAY
NARROWLY ELUDE...IF THE LATEST SHORT RANGE GUIDANCE IS CORRECT.
STILL...GIVEN THAT IT WILL BE A CLOSE CALL...WILL MAINTAIN THE WIND
ADVISORY AS IS FOR NOW...BLANKETING OUR CAPROCK ZONES DURING THE
AFTERNOON HOURS. ADDITIONALLY...THE STRONG WINDS WILL COUPLE WITH
VERY WARM AND DRY CONDITIONS TO PRODUCE WIDESPREAD CRITICAL FIRE
WEATHER CONDITIONS /SEE THE FIRE WEATHER SECTION BELOW FOR
DETAILS/...IN ADDITION TO PATCHY BLOWING DUST.

OTHER LESSER CONCERN IS THAT CONVECTION GENERATED WITHIN THE
RELATIVELY COLD UPPER TROUGH IN A LOW CAPE/CIN ENVIRONMENT ACROSS
THE TEXAS PANHANDLES COULD SNEAK INTO OR NE ZONES LATE THIS
AFTERNOON AND EARLY THIS EVENING BEFORE DISSIPATING. WRF-NAM AND
NCEP AND NSSL WRF RUNS ALL INDICATE THIS POSSIBILITY AND HAVE CHOSEN
TO INCLUDE SLIM SHOWER/STORM CHANCES OVER THE EXTREME SE TX
PANHANDLE IN THE 21-03Z TIMEFRAME.

HIGHS TODAY SHOULD RANGE FROM NEAR AVERAGE ACROSS THE NORTHERN ZONES
TO 5-10 DEGREES ABOVE AVERAGE SOUTH...WITH LOWS TONIGHT DIPPING INTO
THE 40S AND LOWER 50S BEHIND THE FRONT. THERE IS ALSO A SLIM SHOT AT
FOG DEVELOPMENT ACROSS THE CENTRAL AND/OR EASTERN ZONES LATE
TONIGHT...BUT CONFIDENCE IN THIS IS NOT VERY HIGH AND HAVE LEFT OUT
OF THE FORECAST FOR NOW.

LONG TERM...
WV IMAGERY SHOWS THE NEXT UPR-LVL SHORTWAVE TROUGH AND STRONG JET
STREAK JUST COMING ONSHORE IN THE PACIFIC NW. THIS TROUGH WILL
MOVE QUICKLY SEWD...PASSING ACROSS WTX ON TUESDAY. STRONG PRESSURE FALLS
IN ADVANCE OF THE TROUGH OVER NE NM/WRN PANHANDLES WILL QUICKLY ERODE THE
SHALLOW COOL AIRMASS IN THE WAKE OF MONDAY NIGHT/S FRONT. THE BELT OF
STRONGEST MID-LVL WINDS /70 TO 90 KTS AT 500 MB/ WILL NOT ARRIVE
UNTIL AFTERNOON BUT WIND SPEEDS NONETHELESS WILL BE RAMPING UP TUE
MORNING ACROSS THE WRN SPLNS...THEN SPREADING EAST ACROSS MOST OF THE
FA IN THE AFTERNOON. THERE ARE STILL A DISCREPANCY BETWEEN THE GFS
AND NAM REGARDING THE MAGNITUDE OF THE SFC WIND SPEEDS...LIKELY
TIED TO THE NAM DIGGING THE TROUGH SLIGHTLY FARTHER TO THE SOUTH
AND PERHAPS A TAD SLOWER THAN THE GFS. IF THE GFS IS CORRECT
ADVISORY LEVEL WINDS ARE LIKELY FOR MUCH OF THE CAPROCK BY
AFTERNOON WHILE THE NAM GENERALLY KEEPS THE WIND SPEEDS UNDER 30
MPH SUSTAINED. EXPERIENCE SUGGESTS LEANING TOWARD THE NAM WITH AN
ULJ OF THIS MAGNITUDE...BUT IN EITHER CASE...IT WILL BE A WINDY
DAY ACROSS MOST OF THE FA. COUPLED WITH VERY DRY CONDITIONS THE
FIRE DANGER WILL BE VERY HIGH TO EXTREME...AS DISCUSSED FURTHER
BELOW. IN ADDITION...THERE WILL BE LIKELY BE SOME LIFT ASSOCIATED
WITH THE JET STREAK AND SOME INSTABILITY CENTERED IN THE PANHANDLE
ASSOCIATED WITH THE COLD POCKET. FCST SNDGS ACROSS OUR N-NE ZONES
SHOW PERHAPS UP TO 500 J/KG OF MLCAPE TUE AFTERNOON. HIGH-BASED
RA/TSRA ACTIVITY IS EXPECTED TO DEVELOP TO OUR NORTH AND SOME OF
THIS COULD BRUSH OUR NRN ZONES. OF SOME CONCERN WILL BE THE CLOUD
BASES UP AROUND 600 MB WHICH WILL SUPPORT SOME EVAPORATIVE ENHANCEMENT
TO DOWNDRAFTS...ALREADY EMANATING FROM A LEVEL WITH STRONG WINDS.
THIS COULD LEAD TO A THREAT OF SVR WIND GUSTS AT THE
SFC...ALTHOUGH HOPEFULLY THE LOW CAPE WILL LIMIT THE STRENGTH OF
TSTMS. THE WINDS TURN NWERLY BY TUES EVENING BUT WILL CONTINUE TO BE
GUSTY AS THE CORE OF STRONGEST WINDS PASSES ALOFT COINCIDING WITH
STRONG SFC PRESSURE RISES. WINDS WILL SLACKEN FROM WEST TO EAST
LATE WED MORNING AND BECOME LIGHT BY WED EVENING AS SFC RIDGING
SETTLES IN ACROSS TX....LEADING TO A COOL NIGHT ACROSS THE FA.

HIGH TEMPS WEDNESDAY WILL ONLY BE IN THE UPPER 60S TO MIDDLE 70S
BUT THEY WILL BE WARMING BACK UP QUICKLY AS NW FLOW IS QUICKLY
REPLACED BY WEST AND THEN SW FLOW ALOFT. SFC WINDS WILL COME
AROUND TO THE SOUTH ON THU WITH TEMPS BACK IN LOWER 80S...FOLLOWED
BY TEMPS AROUND 90 BY FRI ACCOMPANIED BY BREEZY CONDITIONS AS LEE
TROUGH DEEPENS IN RESPONSE TO A STRONG SHORTWAVE MOVING ACROSS
THE NRN ROCKIES. AS THIS TROUGH MOVES INTO THE PLAINS
SATURDAY...IT WILL DRIVE ANOTHER FRONT SWD INTO THE AREA LIKELY
RESULTING IN COOLER TEMPS SAT AND SUN. THE ECMWF SPLITS THE TROUGH
AND DIGS SOME ENERGY INTO THE SW...NOT REFLECTED IN THE GFS...BUT
IN EITHER CASE...MOISTURE RETURN LOOKS INSUFFICIENT FOR MEANINGFUL
PRECIP CHANCES THROUGH THE WEEKEND INTO EARLY NEXT WEEK.

FIRE WEATHER...
MOIST CONDITIONS WERE IN PLACE EARLY THIS MORNING FROM THE SOUTHERN
PANHANDLE AND CENTRAL SOUTH PLAINS THROUGH THE ROLLING PLAINS.
HOWEVER...DRY AIR POISED ACROSS THE WESTERN SOUTH PLAINS INTO
EASTERN NM WILL QUICKLY ADVANCE OVER THE AREA TODAY AS WESTERLY
WINDS SUSTAINED AT 20-30 MPH AT THE 20 FT LEVEL DEVELOP ACROSS MUCH
OF THE SOUTH PLAINS AND ROLLINGS. THESE GUSTY WINDS WILL COMBINE
WITH TEMPERATURES 5-10 DEGREES ABOVE AVERAGE...HUMIDITIES DROPPING
BELOW 15 PERCENT /BELOW 10 PERCENT ACROSS MUCH OF THE SOUTH PLAINS
AND SOUTHERN ROLLING PLAINS/ AND NEAR RECORD DRY FUELS TO CREATE
CRITICAL FIRE WEATHER CONDITIONS. THE ONLY PLACE THAT MAY ESCAPE THE
CRITICAL CONDITIONS WILL BE THE EXTREME SOUTHEAST TEXAS PANHANDLE
WHERE A QUASI-STATIONARY FRONT MAY STALL OUT THIS AFTERNOON AND KEPT
WINDS LIGHTER AND HUMIDITIES HIGHER. THUS...A RED FLAG WARNING HAS
BEEN ISSUED FOR ALL BUT THE HALL...CHILDRESS AND COTTLE COUNTIES FOR
THIS AFTERNOON AND EARLY EVENING. CONDITIONS WILL IMPROVE TONIGHT AS
WINDS DROP OFF AND THE QUASI-STATIONARY FRONT RETURNS SOUTHWARD WITH
IMPROVED HUMIDITIES. HOWEVER...THE FRONTAL PASSAGE WILL ALSO BRING A
NORTHERLY OR EASTERLY WIND SHIFT WHICH COULD CREATE PROBLEMS FOR
ANY ONGOING FIRE FIGHTING OPERATIONS.

STRONG WINDS WILL SPREAD ACROSS THE AREA ON TUESDAY...COMBINING
WITH A RAPIDLY DRYING AIRMASS TO PRODUCE CRITICAL FIRE WX
CONDITIONS ACROSS THE CAPROCK...AND INTO THE ROLLING PLAINS BY
AFTERNOON. THERE IS SOME QUESTION WHETHER OR NOT THE DRY AIR WILL
MOVE INTO THE FAR SE PANHANDLE AND NRN ROLLING PLAINS BEFORE A
NRLY WIND SHIFT BRINGS A COOLER AND MORE MOIST AIRMASS LATE IN THE
DAY...BUT FOR NOW A FIRE WEATHER WATCH REMAINS IN EFFECT ACROSS
THE ENTIRE AREA. RH VALUES UNDER 10 PERCENT AND SUSTAINED WIND
SPEEDS AROUND 30 MPH MAY RESULT IN AN EXTREMELY CRITICAL FIRE
DANGER ACROSS THE FAR SW PANHANDLE AND WRN SPLNS.

DRY AND BREEZY NW FLOW FOLLOWS ON WEDNESDAY...BUT COOLER TEMPS
WILL TEMPER THE FIRE THREAT. WARMER TEMPS AND INCREASING SW
BREEZES WILL RETURN ON FRIDAY...POSSIBLY RESULTING IN THE NEXT
BOUT WITH CRITICAL FIRE WX CONDITIONS.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        76  40  76  38  70 /  10  10  10  10   0
TULIA         79  43  76  41  69 /  10  10  10  10   0
PLAINVIEW     80  45  79  41  70 /  10  10  10  10   0
LEVELLAND     84  45  83  44  74 /   0   0   0  10   0
LUBBOCK       85  49  82  46  73 /   0   0   0  10   0
DENVER CITY   85  45  87  46  76 /   0   0   0  10   0
BROWNFIELD    85  45  86  46  75 /   0   0   0  10   0
CHILDRESS     80  47  78  48  73 /  20  20  10  20  10
SPUR          88  51  85  49  75 /   0   0  10  10   0
ASPERMONT     91  51  87  51  76 /   0  10  10  10   0

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR
THE FOLLOWING ZONES: TXZ021>024-027>031-033>044.

FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR THE FOLLOWING ZONES: TXZ021>044.

WIND ADVISORY FROM NOON TODAY TO 8 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: TXZ021>024-027>030-033>036-039>042.

&&

23

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE LUBBOCK TX
618 AM CDT MON APR 25 2011

TXZ021>044-261130-
PARMER-CASTRO-SWISHER-BRISCOE-HALL-CHILDRESS-BAILEY-LAMB-HALE-
FLOYD-MOTLEY-COTTLE-COCHRAN-HOCKLEY-LUBBOCK-CROSBY-DICKENS-KING-
YOAKUM-TERRY-LYNN-GARZA-KENT-STONEWALL-
618 AM CDT MON APR 25 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE EXTREME SOUTHERN TEXAS
PANHANDLE...SOUTH PLAINS AND ROLLING PLAINS.

.DAY ONE...TODAY AND TONIGHT

FIRE WEATHER

CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP ACROSS MUCH OF THE
AREA TODAY AS ABOVE AVERAGE TEMPERATURES COMBINE WITH VERY DRY
AIR...GUSTY WESTERLY WINDS AND NEAR RECORD FUEL DRYNESS. A RED FLAG
WARNING IS IN EFFECT FOR THE ENTIRE CAPROCK AND MOST OF THE
ROLLING PLAINS THIS AFTERNOON AND EVENING.

NON PRECIPITATION

WESTERLY WINDS SUSTAINED AT 25 TO 35 MPH ALONG WITH PATCHY BLOWING DUST
WILL DEVELOP ACROSS MUCH OF THE CAPROCK THIS AFTERNOON. A WIND
ADVISORY IS IN EFFECT THIS AFTERNOON FOR LOCATIONS ON THE CAPROCK.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A FIRE WEATHER WATCH IS IN EFFECT TUESDAY AFTERNOON AND EVENING
FOR THE OUTLOOK AREA DUE TO THE COMBINATION OF STRONG
WINDS...AND EXTREMELY DRY CONDITIONS. CRITICAL FIRE
WEATHER CONDITIONS ARE POSSIBLE AGAIN BY LATE IN THE WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.