National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS64 KLUB 151139
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
639 AM CDT SAT MAR 15 2014

.AVIATION...
VFR CONDS LOOK TO PREVAIL FOR THE MAJORITY OF THIS TAF WINDOW.
GREATEST THREAT TO AVIATION ARRIVES THIS EVNG AND OVERNIGHT IN
THE FORM OF STRONG NLY WINDS SUSTAINED NEAR 30 KNOTS BEHIND A
STRONG COLD FRONT. COULD SEE OCCASIONAL MVFR VISBYS AT LBB FROM
BLDU...BUT CONFIDENCE IN THIS BECOMING PREDOMINANT IS NOT HIGH.

OTHER THREAT TO AVIATION WILL BE IN THE FORM OF SOME TSRA LATER
THIS MORNING AND ESPECIALLY THIS AFTN AS AN UPPER IMPULSE TRACKS
EAST FROM WHITE SANDS/NM. SHOULD INITIALLY SEE SCATTERED -SHRA
DEVELOP AT LBB THIS MORNING WITH SOME LOW VFR CIGS BEFORE A
NARROW WINDOW OF TSRA OPENS THIS AFTN DIRECTLY UNDER THE IMPULSE.
CURRENT THINKING IS TSRA WILL BE TOO ISOLATED AT LBB FOR AN
EXPLICIT TAF MENTION. CDS HOWEVER STANDS TO SEE A MUCH BETTER
CHANCE OF TSRA WITH FROPA THIS EVENING.

&&

.PREV DISCUSSION... /ISSUED 415 AM CDT SAT MAR 15 2014/

SHORT TERM...
WELCOME CHANCES FOR RAIN ARE IN THE OFFING FOR PARTS OF THE FORECAST
AREA COURTESY OF GULF MOISTURE ADVECTING NORTHWARD IN ADVANCE OF A
VORT MAX LOCATED OVER WHITE SANDS AT 08Z. EARLY A.M. SURFACE
OBSERVATIONS REVEALED AN AXIS OF 50+F DEWPOINTS IN THE EDWARDS
PLATEAU NORTHWEST TO THE EASTERN PERMIAN BASIN. INCREASING
ISENTROPIC ASCENT AHEAD OF THE VORT MAX WILL ONLY BOLSTER THIS
NORTHWARD ADVECTION OF MOISTURE IN THE COMING HOURS AND THIS IS
ALREADY APPARENT BY THE RECENT UPTICK IN VIRGA AND LOWERING CLOUD
BASES TO OUR SOUTHWEST. OPTED TO RAISE POPS TO HIGH CHANCE LEVELS
OFF THE CAPROCK LATER THIS MORNING GIVEN THESE TRENDS AND PLAUSIBLE
OUTPUT FROM VARIOUS HI-RES MODELS. HPC/S QPF FITS THIS THINKING AS
WELL...SO IT SHOULD NOT BE AN IMPOSSIBLE FEAT TO SQUEAK OUT
MEASURABLE PRECIP ESPECIALLY WITH PWATS AOA 0.75 INCHES.

THE MAIN PUSH OF ISENTROPIC PRECIP LOOKS TO EXIT OUR EASTERN
COUNTIES BY EARLY AFTERNOON AT WHICH POINT OUR ATTENTION WILL TURN
TO THE CENTER OF THE VORT MAX PASSING DIRECTLY OVER OUR SOUTHERN
ZONES BY PEAK HEATING. FAVORABLE TIMING OF THIS IMPULSE COMBINED
WITH INSOLATION UNDERNEATH A -22C COLD POCKET AT 500MB SURE FITS THE
PATTERN FOR SOME AFTERNOON TSTORMS. CAPE ON THE ORDER OF 400-800
J/KG NORMALLY DOESN/T CATCH OUR ATTENTION IN WEAK SHEAR ENVIRONMENTS
SUCH AS THIS...BUT WITH PROGGED INVERTED-V PROFILES AT TIMES AND
STRONG LIFT IN THE VICINITY OF THE VORT MAX...WE COULD EASILY HAVE
TO CONTEND WITH STRONG WIND GUSTS FROM MULTICELL STORMS.

ADDITIONAL LATE DAY AND EARLY EVNG TSTORMS ARE A FAIR BET ACROSS OUR
N-NERN ZONES ALONG A STRONG COLD FRONT ZIPPING SOUTH. THIS FRONT IS
TIED TO A NORTHERN STREAM TROUGH THAT WILL GRADUALLY PHASE WITH THE
AFOREMENTIONED VORT MAX TONIGHT. EARLIER FORECAST REMAINS ON TRACK
ALTHOUGH WE HAVE SCALED BACK MENTION AFTER 06Z AS THE NEWLY
DEVELOPED UPPER TROUGH AXIS LOOKS TO MAKE QUICK HEADWAY SOUTHEAST
NEAR THE I-20 CORRIDOR AHEAD OF DEEPENING SUBSIDENCE.

GREATEST THREAT BY THIS EVENING WILL BE FOR ADVISORY LEVEL WINDS
FOLLOWING THE FRONT. EVEN THOUGH THE CORE OF PRESSURE RISES TAKES
AIM IN THE PLAINS OF ERN NM...RESPECTABLE VALUES ACROSS OUR WESTERN
COUNTIES AND THE DEGREE OF COLD ADVECTION RESULTS IN PERIODS OF DRY
ADIABATIC LAPSE RATES THAT WILL MAXIMIZE MOMENTUM TRANSFER OF 30+
KNOTS AT TIMES. SINCE THIS THREAT IS OVER 12 HOURS OUT AND IS ONLY
FOR ADVISORY WINDS...WE WILL REFRAIN FROM BANGING THE GONG THIS FAR
IN ADVANCE AND LET THE DAY SHIFT DO THE HONORS AND REFINE THE THREAT
AREA EVEN FURTHER.

LONG TERM...
THE MOST PRESSING ITEM OF INTEREST DURING THIS ITERATION OF THE LONG
TERM FORECAST WILL BE THE MAGNITUDE AND DURATION OF STRONG WINDS
DURING THE LATE MORNING/EARLY AFTERNOON SUNDAY...ALONG WITH THE
POTENTIAL FOR LINGERING OR POSSIBLY EVEN REDEVELOPING PRECIPITATION
THROUGH THE EARLY AFTERNOON.

BY EARLY MORNING SUNDAY...THE COLD FRONT AND ITS ASSOCIATED INITIAL
SURFACE PRESSURE RISES WILL BE WELL THROUGH THE AREA...WHICH SHOULD
RESULT IN A MODEST RECESSION OF WIND SPEEDS ALTHOUGH PERHAPS ONLY ON
THE ORDER OF ABOUT 10 MILES AN HOUR OR SO.  HOWEVER...A MID LEVEL
MERIDIONAL JET STREAK IS EXPECTED TO LINGER OVER THE AREA THROUGH
THE DAY SUNDAY...WHICH WILL LIKELY RESULT IN A RAMP UP IN SURFACE
WINDS AS DIURNAL MIXING COMMENCES.  WHILE PERSISTENT COULD COVER AND
COLD AIR ADVECTION WILL PROHIBIT EXCEPTIONALLY DEEP MIXING...IT
SHOULD BE SUFFICIENT TO TAP INTO THE AFOREMENTIONED JET.  AS A
RESULT...WE COULD SEE ADVISORY LEVEL WINDS PERSIST THROUGH THE EARLY
AFTERNOON SUNDAY...BEFORE RAPIDLY TAPERING OFF DURING THE LATE
AFTERNOON AND EVENING HOURS.  MOST AREAS ARE LIKELY TO SEE PATCHY
BLOWING DUST AS WELL...ESPECIALLY ON THE CAPROCK.  AS FOR
PRECIPITATION...THE INITIAL ROUND OF SCATTERED SHOWERS ASSOCIATED
WITH THE FROPA WILL LIKELY BE THROUGH THE AREA BY 12Z...AND THIS
IS EXPECTED TO BE THE END OF MEANINGFUL PRECIPITATION FOR THE DAY.
HOWEVER...LATEST MODEL GUIDANCE...PARTICULARLY THE GFS...SUGGESTS
THAT THE UPPER WAVE RESPONSIBLE FOR OUR GUSTY COLD FRONT MAY BEGIN
TO DEEPEN AS IT PASSES JUST SOUTH OF OUR AREA....AND DEVELOPS A
MODEST TROWAL FEATURE AND ASSOCIATED DEFORMATION BAND DURING THE
AFTERNOON SUNDAY. CURRENT THINKING IS THAT THIS FEATURE AND ITS
QUICK BURST OF LIFT MAY BE A BIT OVERDONE...AND OPTED TO LEAVE OUT
MENTION OF PRECIPITATION BEYOND SUNDAY MORNING FOR NOW.
ALSO...OPTED TO BUMP TEMPERATURES FOR SUNDAY DOWN A FEW
DEGREES...GIVEN PERSISTENT CLOUD COVER AND COLD AIR ADVECTION
THROUGH THE DAY.

FORTUNATELY...CONDITIONS WILL RECOVER QUICKLY ON MONDAY AS RIDGING
ALOFT QUICKLY BUILDS INTO THE AREA.  PRESSURE FALLS ACROSS THE HIGH
PLAINS IN RESPONSE TO AN APPROACHING TROUGH ACROSS THE NORTHERN
ROCKIES WILL LIKELY RESULT IN BREEZY SOUTHWEST SURFACE WINDS ACROSS
AT LEAST AREAS ON THE CAPROCK.  THIS SHOULD ALLOW TEMPERATURES TO
WARM WELL INTO THE 70S...AND MAY EVEN RESULT IN ELEVATED FIRE
WEATHER CONDITIONS JUST ONE DAY REMOVED FROM A CLOUDY...COOL...AND
WINDY DAY IN THE UPPER 40S.  BY TUESDAY MORNING...THE PREVIOUSLY
MENTIONED NORTHERN ROCKIES TROUGH WILL EJECT INTO THE PLAINS WELL TO
OUR NORTH...BUT WILL BRING A MID-LEVEL JET SQUARELY OVERHEAD AS IT
DOES SO.  THIS SHOULD RESULT IN BREEZY WESTERLY WINDS DURING THE
MORNING HOURS TUESDAY...FOLLOWED BY ANOTHER COLD FRONT DURING THE
DAY TUESDAY.  BEYOND TUESDAY...MOSTLY ZONAL FLOW ALOFT WILL SETTLE
INTO THE REGION AS ANOTHER WAVE PREPARES TO MOVE ACROSS THE NORTHERN
PLAINS.  MODELS ARE AT ODDS REGARDING SURFACE DETAILS...AS THE GFS
CONTINUES TO DEPICT RAPID MOISTURE RETURN INTO THE AREA AS EARLY AS
THURSDAY.  CURRENT THINKING IS THAT THIS IS LIKELY OVERDONE GIVEN
THE DEEP ZONAL FLOW ALOFT...BUT WILL BE MONITORED CLOSELY.  IN ANY
CASE...IT APPEARS TO BE A RELATIVELY WARM STRETCH... ALTERNATING
BETWEEN AROUND NORMAL FOLLOWING COLD FRONTS LATE TUESDAY AND
THURSDAY...TO SLIGHTLY ABOVE NORMAL IN BETWEEN.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        66  30  50  29  71 /  20  40  10   0   0
TULIA         67  34  48  28  74 /  30  50  10   0   0
PLAINVIEW     67  35  48  28  75 /  30  50  10   0   0
LEVELLAND     68  36  50  32  75 /  20  40  10   0   0
LUBBOCK       71  37  48  29  75 /  20  40  10  10   0
DENVER CITY   70  35  53  33  74 /  20  30  10   0   0
BROWNFIELD    70  37  51  32  75 /  20  30  10   0   0
CHILDRESS     69  39  50  29  72 /  30  50  10  10   0
SPUR          69  40  48  28  73 /  40  50  10  10   0
ASPERMONT     68  41  46  27  71 /  50  50  10  10   0

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

93