Area Forecast Discussion
Issued by NWS

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114
FXUS64 KLUB 211146
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
646 AM CDT TUE APR 21 2015

.AVIATION...
VFR CONDITIONS THROUGH THE PERIOD. LIGHT WINDS THIS MORNING WILL
EVENTUALLY BECOME SOUTHEASTERLY LATER THIS AFTERNOON INTO THE EVENING.
THERE IS A SLIGHT CHANCE OF SHOWERS OR THUNDERSTORMS LATER
TONIGHT IN THE VICINITY OF KCDS BUT CONFIDENCE TOO LOW AT THIS
POINT TO INCLUDE IN TAFS. THUNDERSTORMS CANNOT BE RULED OUT
ENTIRELY AT KPVW AND KLBB LATER THIS EVENING BUT CHANCES ARE LOW
AND DO NOT WARRANT MENTION IN TAFS AT THIS TIME.

&&

.PREV DISCUSSION... /ISSUED 534 AM CDT TUE APR 21 2015/

SHORT TERM...
DRYLINE APPEARS TO ESTABLISH ITSELF JUST OFF THE CAPROCK BY LATE
AFTERNOON TODAY WITH THE 50 DEWPOINT ISODROSOTHERM STRUGGLING TO
MAKE IT FAR ENOUGH WEST ONTO THE CAPROCK. GIVEN THE MEAGER GULF
MOISTURE RETURN AND VARYING MAGNITUDE OF CAPPING ISSUES...ALONG
WITH CONFLUENT FLOW ALOFT ACROSS WEST TEXAS CANNOT SEE A SCENARIO
THAT ALLOWS FOR ANY SHOWER OR THUNDERSTORM DEVELOPMENT. WHICH IS
SUPPORTED BY THE HIRES NAM...GFS AND ECMWF ALL FAILING TO INITIATE
CONVECTION IN OUR AREA LATER TODAY/EARLY THIS EVENING ALONG AND
OUT AHEAD OF THE DRYLINE. OPERATIONAL NAM HINTS TOWARD CONVECTION
IN THE HIGHER TERRAIN OF SE NM INTERACTING WITH THE RETREATING
DRYLINE LATER IN THE EVENING POSSIBLY REACHING SOUTHWEST ZONES
ALONG THE TX/NM BORDER. NOT GIVING MUCH CREDENCE TO THAT
PARTICULAR SOLUTION. DUE TO THE VERY POOR HANDLING OF OVERNIGHT
CONVECTION MONDAY INTO TODAY. INITIALLY HAD NO CATEGORICAL POPS
FOR THE AFTERNOON/EVENING PERIOD BUT DID BUMP UP TO SLIGHT CHANCE
POPS TO BETTER ALIGN WITH NEIGHBORS.

AFTER MIDNIGHT THE NAM AND GFS INDICATE LOOSELY ORGANIZED
CONVECTION OUT OF NE NM INTO THE TEXAS PANHANDLE. RIGHT NOW THAT
ACTIVITY IS WELL NORTH OF OUR CWA BUT IF IT WERE TO DROP FAR
ENOUGH SOUTH AND INTERACT WITH A RETREATING DRYLINE WE COULD SEE
SOME ISOLATED ACTIVITY OVERNIGHT IN OUR NORTHERN ZONES BUT EVEN
THAT IS A FAR REACH AT THIS POINT GIVEN THE LARGE SURFACE DEWPOINT
DEPRESSIONS AND LACK OF INSTABILITY ALOFT IN THE PROFILES.

ADDING TO THE DIFFICULTY TO INITIATE STORMS WILL BE THE LACK OF
SURFACE BASED CAPE DUE TO MODEST CLOUD COVER WHICH IS LIKELY THE
REASON GUIDANCE HAS LOWERED HIGHS FOR TUESDAY BY ROUGHLY A DEGREE
OR TWO ACROSS OUR AREA...GENERALLY IN THE MID TO UPPER 70S. CLOUD
COVER OVERNIGHT WILL KEEP LOWS INTO WEDNESDAY MILD GENERALLY IN
THE LOW TO MID 50S WITH A USUAL COOL POCKET IN OUR NORTHWEST ZONES
INTO THE MID 40S.

LONG TERM...
ONGOING CONVECTION STEMMING FROM OVERNIGHT STORMS...COURTESY OF A
NOCTURNAL LOW LEVEL JET...MAY STILL BE IN VICINITY OF THE FAR
SOUTHEAST PANHANDLE/EASTERN ROLLING PLAINS COME DAYBREAK WEDNESDAY.
LINGERING OUTFLOW BOUNDARIES FROM THIS ACTIVITY WILL ONLY FURTHER
ADD TO BUSY SURFACE FIELDS...CHARACTERIZED BY A CLOSED LOW IN
EASTERN NEW MEXICO WITH AN ATTENDANT WARM/QUASI-STATIONARY FRONT
DRAPED ACROSS THE SOUTHERN HIGH PLAINS ALONG WITH A DRYLINE IN
VICINITY OF THE CAPROCK. NEGATIVELY TILTED RIDGING WILL BUILD IN
ALOFT ALLOWING WARMER AIR TO SPILL IN OUT OF THE SOUTHWEST...RAISING
CONCERNS AS TO AFTERNOON INITIATION ALONG THE DRYLINE DUE TO
CAPPING. THE PRESENCE OF A SUBTROPICAL JET ALOFT AND PLENTY OF DEEP
LAYER SHEAR SHOULD HELP PROMOTE STORM GENERATION ALONG/EAST OF THE
DRYLINE IN THE PRESENCE OF ANY SHORTWAVE PERTURBATIONS MOVING
OVERHEAD. INCREASING LOW LEVEL FLOW AND SUBSEQUENT LENGTHENING
HODOGRAPHS SHOULD PROMOTE ELEVATED STORMS INTO THE EVENING AND
OVERNIGHT HOURS...ESPECIALLY IN CLOSE PROXIMITY TO THE SOUTHERN
EXTENT OF THE SYNOPTIC FRONTAL BOUNDARY WHERE ENHANCED DIRECTIONAL
SHEAR WILL HELP BALANCE A DEVELOPING COLD POOL ORIGINATING FROM A
NOCTURNAL MCS. WILL THUS MAINTAIN HIGHEST POPS ACROSS THE FAR
SOUTHEAST PANHANDLE INTO THE NORTHEASTERN ROLLING PLAINS WHERE THIS
SETUP APPEARS MORE FAVORABLE TO DELIVER STORMS.

THURSDAY/S CHANCES FOR STORMS WILL HEAVILY DEPEND ON WHAT
MATERIALIZES OVERNIGHT WEDNESDAY INTO THURSDAY IN TERMS OF OUTFLOW
BOUNDARY PROPAGATION AND ASSOCIATED SURFACE BOUNDARY POSITIONING.
INCREASING SOUTHWESTERLY FLOW AHEAD OF A NEGATIVELY TILTED UPPER
LOW EJECTING OUT OF SOUTHERN CALIFORNIA TOWARD THE FOUR CORNERS
REGION WILL SEND THE AFOREMENTIONED WARM FRONT NORTHWARD THROUGH
THE CENTRAL PLAINS AS LEE TROUGHING IN THE FRONT RANGE ATTEMPTS TO
HOLD THE DRYLINE NEAR THE CAPROCK ESCARPMENT BY PEAK HEATING.
STORMS WILL ONCE AGAIN HAVE THE BEST CHANCE TO FIRE ACROSS THE
LOWER ROLLING TERRAIN...BUT INCREASING WARMTH ALOFT WILL IN ALL
LIKELIHOOD FURTHER STRENGTHEN THE CAP.

UPPER LOW LOOKS TO MOVE INTO WESTERN KANSAS BY LATE FRIDAY
AFTERNOON/EARLY EVENING...POSSIBLY SPELLING A WINDY DAY WITH
SUSTAINED SPEEDS APPROACHING 25-30 MPH. DRY DOWNSLOPE WINDS WILL
SEND THE DRYLINE WELL EAST OF THE ROLLING PLAINS AND LEAD TO A
TOASTY DAY WITH TEMPERATURES MAINLY IN THE 80S.

SHORTWAVE RIDGING WILL THEN TAKE HOLD SATURDAY BEFORE A DISTURBANCE
MOVES TOWARD THE PLAINS BY THE END OF THE WEEKEND. STILL QUESTIONS
AS TO THE STRENGTH/SPEED OF THIS UPPER WAVE WHICH WILL HAVE A
NOTABLE IMPACT ON MOISTURE RETURN...BUT SLIGHT CHANCE POPS OUT EAST
SEEM WARRANTED AT THIS JUNCTURE BEFORE RIDGING AND DRY CONDITIONS
ENSUE FOR EARLY-MID WEEK WITH TEMPERATURES HOLDING NEAR CLIMO.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        75  43  81  43 /   0  20  20  10
TULIA         75  52  78  47 /   0  20  20  20
PLAINVIEW     76  52  78  49 /   0  20  20  20
LEVELLAND     78  53  81  49 /  10  20  20  10
LUBBOCK       78  54  82  52 /   0  20  20  10
DENVER CITY   78  54  83  50 /   0  20  20   0
BROWNFIELD    79  56  83  51 /   0  20  20  10
CHILDRESS     77  55  76  57 /  10  20  30  40
SPUR          77  57  79  55 /   0  20  30  20
ASPERMONT     79  60  81  60 /  10  20  30  20

&&

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

$$

55/99/

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