Area Forecast Discussion
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FXUS64 KLUB 062031
AFDLUB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
331 PM CDT FRI MAY 6 2016

.SHORT TERM...
THE UPPER LOW CURRENTLY SEEN CHURNING OVER CALIFORNIA IN WATER VAPOR
IMAGERY THIS AFTERNOON IS PROGGED TO ELONGATE NORTHEAST THROUGH THE
FOUR CORNERS WITH A LEAD IMPULSE EMERGING OVER THE CENTRAL HIGH
PLAINS SATURDAY AFTERNOON. THE HIGH AMPLITUDE UPPER RIDGE DOWNSTREAM
OF THE LOW OVER THE SOUTHERN PLAINS THIS AFTERNOON WILL YIELD TO
INCREASING SOUTHWESTERLY FLOW ALOFT TONIGHT INTO SATURDAY. IN
ADDITION...A COUPLE OF WEAK DISTURBANCES WITHIN THE DEVELOPING
SOUTHWEST FLOW MAY GRAZE THE AREA FROM THE SOUTH LATE TONIGHT AND
AGAIN LATE SATURDAY...THOUGH THE BULK OF THE LARGE SCALE FORCING
WILL REMAIN NORTH OF THE AREA.

IN ADVANCE OF THE UPPER LOW WE HAVE ALREADY SEEN FALLING PRESSURES
TO OUR WEST COMBINE WITH THE SURFACE HIGH WELL TO OUR EAST CREATE A
FAIRLY TIGHT PRESSURE GRADIENT LOCALLY. THIS PRESSURE GRADIENT HAS
SUPPORTED SOUTHERLY WINDS SUSTAINED IN THE 20 TO 30 MPH RANGE ON THE
CAPROCK...WITH WINDS A NOTCH LOWER FURTHER EAST. THESE WINDS WILL
WEAKEN MODESTLY TONIGHT WITH THE LOSS OF DEEP MIXING ALONG WITH A
SLIGHT RELAXING OF THE PRESSURE GRADIENT. HOWEVER...SIMILAR
MAGNITUDE WINDS WILL RETURN SATURDAY AS A DRYLINE GRADUALLY SHARPENS
AND MIXES EASTWARD ACROSS THE SOUTH PLAINS. THE LATEST NWP SUGGESTS
A DRYLINE POSITION SOMEWHERE NEAR THE I-27/US-87 CORRIDOR BY PEAK
HEATING. GIVEN THAT DEWPOINTS ARE ONLY IN THE 40S AND 50S ALONG
COASTAL TEXAS...MOISTURE RETURN IN ADVANCE OF THE DRYLINE WILL BE
LIMITED...BUT WE SHOULD SEE DEWPOINTS SOMEWHERE NEAR THE 50 DEGREE
MARK. THIS WILL KEEP INSTABILITY ON THE LOWER SIDE...THOUGH WITH
STEEP MID-LEVEL LAPSE RATES WE COULD SEE MUCAPES AROUND 1000 J/KG BY
LATE AFTERNOON. ALTHOUGH UPPER SUPPORT WILL BE MINIMAL...WEAK
INHIBITION AND FORCING ALONG THE DRYLINE MAY BE ENOUGH TO INITIATE
ISOLATED TO WIDELY SCATTERED CONVECTION LOCALLY SATURDAY AFTERNOON
AND EVENING. IF STORMS DO FORM...STRONG DEEP LAYER SHEAR INCREASING
TO 40 TO 50 KNOTS COULD SUPPORT SOME ORGANIZATION...INCLUDING A HIGH-
BASED SUPERCELL OR TWO CAPABLE OF PRODUCING LARGE HAIL AND STRONG
DOWNBURST WINDS. BEFORE THEN...THERE IS A SLIM CHANCE OF AN ELEVATED
SHOWER OR STORM LATE TONIGHT INTO SATURDAY MORNING AS THE WEAK
SUBTROPICAL DISTURBANCE TRANSLATES BY...BUT DRY LOW-LEVELS WILL KEEP
PROSPECTS FOR MEASURABLE PRECIPITATION LOW.

TEMPERATURES WILL BE ON THE WARM SIDE AGAIN WITH PLENTY OF MIDDLE AND
UPPER 80S AGAIN TOMORROW AFTER LOWS TONIGHT IN THE UPPER 40S TO
50S.

.LONG TERM...
AN UPPER LEVEL VORT MAX LIFTING FROM THE BASE OF A LOW CENTERED
OVER THE NRN COLORADO ROCKIES SUNDAY WILL PUSH THE DRYLINE EWD
ACROSS THE FCST AREA...VERY LIKELY TO WITHIN 15 MILES...EAST OR
WEST...OF THE ERN BOUNDARY OF THE FCST AREA BY 21Z. THIS SHOULD
EFFECTIVELY LIMIT AFTERNOON PRECIP CHANCES ACROSS THE ROLLING
PLAINS TO 10 PCT OR LESS WHILE SPREADING LOW-END ADVISORY LEVEL
WINDS ACROSS THE SOUTH PLAINS. A SECOND LOBE OF VORTICITY DROPPING
INTO THE BASE OF THE TROUGH WILL DRAW THE DRYLINE BACK TO THE
WEST A BIT DURING THE EVENING...MAINLY ON THE SRN END...WITH THE
POTENTIAL FOR SOME CONVECTIVE DEVELOPMENT IN OR NEAR THE SERN
ZONES SUNDAY EVENING. THAT SECOND LOBE WILL ROTATE NEWD SUNDAY
NIGHT PUSHING THE DRYLINE TO THE EAST OF THE FCST AREA MONDAY. THE
UPPER LOW WILL EJECT ACROSS THE CNTL PLAINS MONDAY NIGHT. A COLD
FRONT ON THE BACK SIDE OF IT PROBABLY WILL NOT MAKE IT TO THE FCST
AREA...BUT ADDITIONAL EMPHASIS FROM ANOTHER UPPER LOW...THIS ONE
EJECTING ONTO THE NRN PLAINS TUESDAY NIGHT...WILL PUSH THE FRONT
THROUGH THE FCST AREA WEDNESDAY. UNTIL THEN TEMPS GENERALLY QUITE
A BIT ABOVE NORMAL...BOTH HIGHS AND LOWS.

TRANSITION IN THE PATTERN LATTER HALF OF THE WEEK. WITH LOW
AMPLITUDE FLOW ACROSS THE SRN HALF OF THE CONUS...NEAR ZONAL FLOW
FOLLOWED BY WEAK RIDGING HEADING INTO THE WEEKEND. SOME MODEST LOW
LEVEL MOISTURE AND POTENTIAL FOR WEAK CAPPING SUGGEST SMALL CHANCE
FOR PRECIP AT THIS POINT IN THE FCST PERIOD WHILE TEMPERATURES AT
LEAST BRIEFLY MODERATE TO NEAR SEASONAL NORMS.

&&

.FIRE WEATHER...
GUSTY...WARM AND DRY SOUTHERLY WINDS WERE CREATING PERIODS OF
CRITICAL FIRE WEATHER OVER A GOOD CHUNK OF THE SOUTHWEST TEXAS
PANHANDLE AND WESTERN AND CENTRAL SOUTH PLAINS THIS AFTERNOON. THESE
CONDITIONS WILL IMPROVE THIS EVENING AS WINDS WEAKEN AND RH VALUES
RISE...BUT A RETURN OF CRITICAL FIRE WEATHER IS LIKELY WEST OF THE
DRYLINE ACROSS THE WESTERN INTO THE CENTRAL SOUTH PLAINS SATURDAY
AFTERNOON. THE ONE BIG LIMITING FACTOR TO THE FIRE DANGER IS THE
FUELS WHICH HAVE GREENED UP...THOUGH RESIDUAL PATCHES OF CURED FUELS
FROM LAST YEAR DO STILL EXIST. GIVEN THE STATE OF THE FUELS...WE DO
NOT CURRENTLY ANTICIPATE ISSUING ANY FIRE WEATHER WATCHES OR RED
FLAG WARNINGS...BUT A FIRE DANGER STATEMENT MAY BE CONSIDERED GIVEN
THE REPEATED CRITICAL FIRE WEATHER THAT COULD LOCALLY RAISE THE
FIRE DANGER.

&&

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

$$

23/07



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