Area Forecast Discussion
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FXUS64 KLUB 031721
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
1221 PM CDT SUN MAY 3 2015

.AVIATION...
VFR CONDITIONS EARLY THIS AFTERNOON AS SOUTH TO SOUTHWEST WIND
SPEEDS HAVE PICKED UP A BIT /13-17 KTS/...WITH HIGHEST SPEEDS
NOTED AT KCDS. FEW-SCT VFR DECKS PASS OVERHEAD. ISOLATED
-SHRA/-TSRA ARE EXPECTED TO DEVELOP WEST OF KLBB AND KPVW LATE
THIS AFTERNOON/EARLY THIS EVENING...AND COULD DRIFT EAST AND
POSSIBLY IMPACT THE SAID TERMINALS. CONFIDENCE IS NOT HIGH TO
INSERT A PREVAILING LET ALONE A TEMPO...THOUGH A PROB30 WOULD BE
MORE SUFFICIENT BUT UNABLE INSERT A PROB30 WITHIN THE FIRS 9
HOURS OF A TAF. AS SUCH...WILL HOLD OFF ON AN INSERT AT THIS TIME
BUT WILL OF COURSE AMEND AS NECESSARY. WIND SPEEDS WILL DECLINE TO
AOA 10 KTS AOA 04/06Z. OVERNIGHT...CLOUD DECKS WILL DETERIORATE TO
MVFR AS LOW LEVEL MOISTURE INCREASES. CAN NOT RULE OUT LIGHT VFR
FOG BUT WILL LEAVE OUT THE FOG MENTION FOR NOW. -SHRA MAY LINGER
WEST OF THE KLBB AND KPVW OVERNIGHT AS WELL. MVFR DECKS WILL
PERSIST THROUGH LATE MONDAY MORNING/EARLY AFTERNOON...WHILE
COMPUTER MODELS INDICATE THE POTENTIAL FOR -SHRA/-TSRA DEVELOPING
SOUTH OF KLBB AND IMPACTING SAID TERMINAL AS WELL AS KPWV BY LATE
MONDAY MORNING. HAVE INSERTED A PROB30 FOR THIS POTENTIAL.

&&

PREV DISCUSSION... /ISSUED 405 AM CDT SUN MAY 3 2015/

SHORT TERM...
AFTER THE RECENT QUIET STRETCH OF WEATHER THINGS WILL BEGIN TRENDING
TOWARD THE MORE ACTIVE SIDE...STARTING TODAY. THE UPPER RIDGE THAT
HAS BEEN PROVIDING THE WARM AND DRY CONDITIONS OF LATE IS BEGINNING
TO SHIFT EASTWARD. THIS WILL OPEN THE DOOR FOR A PROLONGED PERIOD OF
UNSETTLED SOUTHWEST FLOW ALOFT. IN FACT...ONE WEAK SHORTWAVE TROUGH
EMBEDDED IN THE DEVELOPING SOUTHWEST ACROSS NORTHERN CHIHUAHUA AND
SOUTHWEST NEW MEXICO SHOULD BE WELL TIMED TO PROVIDE A LITTLE ADDED
LARGE SCALE LIFT LATER THIS AFTERNOON INTO THIS EVENING. THE ONE
LIMITING FACTOR TODAY WILL BE THE LOW-LEVEL MOISTURE...AS 08Z
DEWPOINTS ARE MOSTLY IN THE LOWER TO MIDDLE 40S ON THE
CAPROCK...WITH UPPER 40S AND LOWER 50S COMMON FURTHER EAST OVER THE
LOWER ELEVATIONS. BREEZY SOUTHERLY WINDS THIS AFTERNOON WILL ATTEMPT
TO HOLD THE MOISTURE IN TODAY...BUT IT STILL APPEARS DEEP MIXING
WILL LIKELY DROP DEWPOINTS INTO THE 30S NEAR THE TX/NM LINE THIS
AFTERNOON AS A DIFFUSE DRYLINE TAKES SHAPE.

ALL INDICATIONS ARE THAT STRONG HEATING COUPLED WITH THE FORCING
ALONG/NEAR THE DRYLINE/SURFACE TROUGH AND WEAK UPPER SUPPORT SHOULD
BE ENOUGH TO ERODE ANY CAP AND LEAD TO THE DEVELOPMENT OF SCATTERED
HIGH-BASED CONVECTION THIS AFTERNOON. THE CONVECTION WILL INITIALLY
DEVELOP ACROSS EASTERN NEW MEXICO INTO THE WESTERN SOUTH PLAINS BY
MID- TO LATE AFTERNOON BEFORE SPREADING SLOWLY EASTWARD. DEEP
LAYER SHEAR WILL BE ON THE LOW SIDE TODAY WITH PROGGED MLCAPE CAPE
GENERALLY AOB 1000 J/KG ACROSS THE WESTERN ZONES...SO THIS SHOULD
LIMIT STORM ORGANIZATION AND STRENGTH. HOWEVER...A DEEP AND DRY
SUB-CLOUD LAYER COULD PROMOTE A FEW STRONG TO SEVERE WIND GUSTS
WITH ANY STRONG CORES ALOFT. IN ADDITION...VERY STEEP MID-LEVEL
LAPSE RATES MAY ALSO LEND TO BRIEF BOUTS OF SMALL HAIL WITH THE
MOST ROBUST UPDRAFTS. UNFORTUNATELY...THE RELATIVELY DRY LOW-
LEVELS WILL LIMIT PRECIPITATION EFFICIENCY AND OVERALL RAIN
COVERAGE/AMOUNTS. STILL...IT DOES APPEAR COVERAGE WILL BE
WIDESPREAD ENOUGH TO CONTINUE SOLID CHANCE POPS ACROSS MUCH OF THE
SOUTHWEST TEXAS PANHANDLE AND WESTERN SOUTH PLAINS LATE THIS
AFTERNOON INTO THIS EVENING.

AS THE ACTIVITY EDGES EASTWARD THIS EVENING IT WILL ENCOUNTER BETTER
MOISTURE AND INSTABILITY...BUT ALSO INCREASING INHIBITION. THE
INCREASING CIN WILL LIKELY LIMIT HOW FAR EAST THE CONVECTION CAN
PROPAGATE AND MOST GUIDANCE SUGGESTS A RATHER SHARP CUTOFF FOR THE
CONVECTION SOMEWHERE NEAR THE I-27/US-87 CORRIDOR TO THE EASTERN
EDGE OF THE CAPROCK. THE BULK OF THE ACTIVITY SHOULD FADE LATE THIS
EVENING...THOUGH ENOUGH MID-LEVEL MOISTURE AND LIFT COULD KEEP A FEW
SHOWERS GOING AFTER MIDNIGHT. IN ADDITION...A MORE SIGNIFICANT SURGE
OF LOW-LEVEL MOISTURE SHOULD FINALLY MAKE ITS WAY INTO THE SOUTHERN
ZONES BY EARLY MONDAY...COMPLETE WITH STRATUS AND THE PROMISE OF
MORE WIDESPREAD RAIN TO COME OVER THE NEXT COUPLE OF DAYS.

REGARDING TEMPERATURES...TODAY WILL BRING ANOTHER WARM EARLY MAY
DAY...WITH AFTERNOON HIGHS WELL INTO THE 80S. TONIGHT WILL BE
MILD...BOTTOMING OUT IN THE UPPER 50S AND LOWER 60S FOR MOST
LOCALES.

LONG TERM...
LOCALLY HEAVY RAINFALL POSSIBLE MONDAY NIGHT AND TUESDAY...

THE BULK OF THE FORECAST REMAINS ON TRACK FOR SOME SIGNIFICANT
RAINFALL ACROSS THE FORECAST AREA MONDAY AND TUESDAY...LIKELY TO
BE ACCOMPANIED BY SOME SEVERE WEATHER AS WELL.

DURING THIS PERIOD AN UPPER LOW WILL TRACK OUT OF SRN CA/NRN BAJA
NEWD ACROSS THE 4-CORNERS AREA...WITH THE TROUGH AXIS PASSING
ACROSS OUR AREA LATE TUESDAY...MOVING PERHAPS JUST SLIGHTLY
SLOWER THAN PREVIOUS MODEL ITERATIONS. AHEAD OF THE MAIN
TROUGH...WE EXPECT A FAIRLY WELL-DEFINED LEAD WAVE TO PASS ACROSS
WEST TEXAS...AND PROVIDE THE INITIAL IMPETUS FOR CONVECTIVE
DEVELOPMENT MONDAY AFTERNOON. FAIRLY RICH LOW-LVL MOISTURE SHOULD
ALREADY BE IN PLACE...WITH THE DRYLINE HAVING RETREATED INTO ERN
NM SUNDAY NIGHT. DESPITE MORNING STRATUS AND COOLER SURFACE
TEMPS...MONDAY/S HIGHS ARE EXPECTED TO BE MAINLY IN THE MIDDLE TO
UPPER 70S...COOLING TEMPS ALOFT AND STEEP LAPSE-RATES SHOULD
ALLOW FOR CINH TO ERODE QUICKLY AND T-STORM DEVELOPMENT THROUGH
THE AFTERNOON HOURS. ALTHOUGH CONVECTION MAY OCCUR PRETTY MUCH
ANYWHERE...WE/LL FOCUS ON THE WRN AND ESPECIALLY THE SW SPLNS
WHICH WILL BE LOCATED UNDERNEATH THE STRONGER ASCENT AND
INSTABILITY. CAPES IN THIS AREA MAY REACH 2000 J/KG OR SO AND THIS
AREA WILL ALSO BE ON THE NRN PERIPHERY OF STRONGER MID-LVL FLOW
ASSOCIATED WITH THE SUB-TROPICAL JET. THIS WILL RESULT IN A
THREAT OF SEVERE THUNDERSTORMS...GENERALLY TO THE SOUTH AND WEST
OF LUBBOCK. FARTHER TO THE NORTH AND EAST...DIMINISHING CAPE AND
SHEAR SHOULD LIMIT THE SEVERE POTENTIAL.

T-STORMS MAY REALLY GET GOING ACROSS ERN NM AND THE WESTERN SOUTH
PLAINS MONDAY EVENING AS THE LLJ CRANKS UP IN RESPONSE TO THE
INCOMING TROUGH. GUIDANCE IS IN BROAD AGREEMENT SHOWING A SWATH OF
HIGH QPF NEAR THE STATE LINE AND EXTENDING NEWD INTO THE SRN TX
PANHANDLE EARLY TUESDAY MORNING. THE GFS HAS AT TIMES SHOWN A
SECOND HIGH QPF SIGNAL ACROSS THE NRN PERMIAN BASIN...WHICH IF IT
OCCURRED COULD INTERCEPT SOME OF THE MOISTURE HEADING
NEWD...SOMETHING TO WATCH FOR. WITHIN THIS SWATH...WE COULD SEE
THE TRAINING OF MODERATE TO HEAVY THUNDERSTORMS WHICH WILL BRING
THE THREAT OF HEAVY RAINFALL /2-3 INCHES WITH LOCALLY HIGHER
AMOUNTS/ AND POSSIBLE FLOODING. A FLOOD WATCH MAY BE CONSIDERED
FOR PORTIONS OF THIS AREA.

THE TUESDAY FORECAST WILL DEPEND GREATLY ON THE LOCATION AND
EXTENT OF OVERNIGHT AND EARLY MORNING CONVECTION AND ANY OUTFLOW
BOUNDARY/IES/. THE BEST INDICATIONS ARE THAT WE WILL HAVE ONGOING
STORMS TUESDAY MORNING...CONCENTRATED ACROSS THE FAR SRN TX
PANHANDLE. THIS ACTIVITY MAY LAY DOWN A BOUNDARY WHICH MAY BECOME
THE FOCUS FOR ADDITIONAL DEVELOPMENT TUESDAY
AFTERNOON...ESPECIALLY IF WE CAN GET SOME PARTIAL CLEARING.
AFTERNOON AND EVENING T-STORM DEVELOPMENT WILL FAVOR AREAS TO THE
SOUTH OF THE OUTFLOW BOUNDARY...WHERE THE BETTER POTENTIAL
INSTABILITY SHOULD RESIDE. MID-LVL FLOW WILL STRENGTHEN
CONSIDERABLY TUESDAY AND DEEP-LAYER SHEAR SHOULD BE MORE THAN
SUFFICIENT TO SUPPORT ROTATING UPDRAFTS PROVIDED THERE IS ENOUGH
BUOYANCY. HOWEVER...WITH SURFACE FIELDS LIKELY TO BE MESSY AND THE
UNCERTAINTY WITH CAPE PRODUCTION...THE SEVERE THREAT SEEMS HIGHLY
CONDITIONAL AT THIS TIME. FINALLY...THE DRYLINE MAY OR MAY NOT
MOVE BACK INTO WEST TEXAS TUESDAY.

WE SHOULD SEE A BREAK IN THE ACTION WEDNESDAY ALTHOUGH THE DRYLINE
WILL LIKELY LINGER SOMEWHERE IN THE ROLLING PLAINS AND SUPPORT A
CHANCE OF AFTERNOON AND EVENING T-STORMS IN THAT AREA. THU INTO
FRI...THE WESTERN CONUS TROUGH RELOADS WITH AN UPPER LOW DIGGING
SWD THROUGH THE GOLDEN STATE. ENERGETIC SW FLOW ALOFT AND A
SLOSHING DRYLINE WILL MAINTAIN DIURNAL T-STORMS CHANCES EACH DAY
FOR ROUGHLY THE EASTERN 2/3RDS OF THE FORECAST AREA POSSIBLY INTO
SATURDAY AS WELL. SMALL IMPULSES MOVING THROUGH THE SW FLOW ARE
DIFFICULT TO TIME...BUT THERE APPEAR TO BE SUCH IMPULSES INCOMING
BOTH THURSDAY AND FRIDAY. AFTER TUESDAY...TEMPS FOR THE UPCOMING
WEEK SHOULD BE SEASONABLE.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        54  75  54  71 /  30  40  80  70
TULIA         57  75  56  68 /  30  20  70  80
PLAINVIEW     58  74  56  69 /  30  20  70  80
LEVELLAND     59  75  57  73 /  40  40  80  70
LUBBOCK       61  75  58  73 /  20  30  70  70
DENVER CITY   58  76  57  76 /  30  40  80  60
BROWNFIELD    59  76  58  77 /  30  40  70  60
CHILDRESS     61  79  60  71 /  10  20  50  70
SPUR          59  76  58  71 /  10  20  60  70
ASPERMONT     61  79  61  74 /   0  20  50  70

&&

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

$$

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