620
FXUS64 KLUB 182336
AFDLUB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
636 PM CDT MON MAR 18 2019
AVIATION
VFR WILL PREVAIL THE NEXT 24 HOURS, THOUGH CLOUDS WILL BEGIN TO
THICKEN TUESDAY AFTERNOON AHEAD OF A WEAK COLD FRONT. THE FROPA
WILL LIKELY OCCUR AROUND OR JUST AFTER THE END OF THE FORECAST
WINDOW AT THE NORTHERN TERMINALS. BEFORE THEN, SOUTHERLY TO
SOUTHWESTERLY WINDS WILL BECOME A LITTLE BREEZY ON TUESDAY.
PREV DISCUSSION
/ISSUED 216 PM CDT MON MAR 18 2019/
DISCUSSION...
UNUSUAL FOR EARLY SPRING IN WEST TEXAS, ANEMIC WINDS WERE THE
STORY NOT JUST AT THE SURFACE BUT ALL THROUGHOUT THE TROPOSPHERE.
THIS WAS DUE TO A WEAK UPPER LOW CRAWLING EAST ACROSS FAR WEST
TEXAS THIS AFTERNOON IN BETWEEN TWO BRANCHES OF THE POLAR JET TO
ITS NORTH AND SOUTH. BESIDES A SMATTERING OF HIGH CLOUDS AND SOME
BOUNDARY LAYER CUMULUS PRECEDING THIS DECAYING LOW, NO IMPACTS ARE
EXPECTED THROUGH TONIGHT AS THIS LOW CONTINUES TO WEAKEN BEFORE
EVENTUALLY SHEARING APART TOMORROW MORNING OVER THE HILL COUNTRY.
SOME OF THIS SHEARING WILL BE AIDED BY A TROUGH CARVING SOUTHWARD
WITHIN THE STRONGER BRANCH OF THE POLAR JET. THIS DEEPER TROUGH
STILL APPEARS CAPABLE OF SUPPORTING A FEW VERY LIGHT RAIN SHOWERS
TOMORROW AFTERNOON, GENERALLY IN OUR SOUTHWEST PANHANDLE COUNTIES
NEAR A COLD FRONT. RAIN CHANCES BY TUE NIGHT LOOK TO FOCUS MORE
ALONG THE TRAILING FN LAYER ALOFT WHICH IS PROGGED TO TRANSLATE
VERY LITTLE NORTH OR SOUTH FROM OUR PANHANDLE COUNTIES ALL NIGHT
LONG. BACKGROUND ASCENT TOMORROW NIGHT CERTAINLY LOOKS MORE
FAVORABLE COMPARED TO THE AFTERNOON GIVEN IMPROVING PVA AHEAD OF
THE UPPER TROUGH AXIS AND DECENT UPPER DIVERGENCE AT TIMES.
FOLLOWING TUESDAY NIGHT'S TROUGH AND COLD FRONT, COOL SURFACE
RIDGING ENSUES ON WEDNESDAY UNDERNEATH A PROGRESSIVE LONGWAVE
RIDGE. MODELS ARE IN GOOD AGREEMENT THAT THIS RIDGE WILL LOITER A
BIT LONGER THROUGH THURSDAY AND SERVE TO KEEP MOST/ALL OF THE
REGION DRY BEFORE AN INFLUX OF SUBTROPICAL MOISTURE ARRIVES THU
NIGHT AND ESPECIALLY FRI AHEAD OF A SLOW MOVING CLOSED LOW THROUGH
THE FOUR CORNERS. MEANWHILE, LOW LEVEL MOISTURE RECOVERY LOOKS TO
MAKE GREAT STRIDES THANKS TO DEEP MERIDIONAL FLOW ADVECTING GULF
MOISTURE NORTHWARD. THIS PROCESS SHOULD ESTABLISH AN AXIS OF PWATS
0.75" OR GREATER BY FRIDAY OVER MOST OF THE REGION COLLOCATED
WITH DECENT MID-LEVEL LAPSE RATES AROUND 8*C/KM WHICH WOULD EASILY
BE SUPPORTIVE OF THUNDER. HOWEVER, MLCAPE AS A WHOLE APPEARS
SUBDUED FOR MOST OF THE DAY ON FRIDAY UNDERNEATH THICK CLOUDS AND
MARGINAL INSOLATION, SO THE SEVERE THREAT COULD BE TEMPERED IN
FAVOR OF OCCASIONAL HEAVY RAIN GIVEN SUCH DEEP SOUTHERLY FLOW FROM
THE SURFACE TO 300 MB AND POTENTIAL FOR TRAINING CELLS. SUPERBLEND'S
BULLISH POPS WERE KEPT LARGELY ON TRACK GIVEN THE FAVORABLE PATTERN
AND LONG RESIDENCE TIME OF MOISTURE AND ASCENT, BUT THE GREATEST
WINDOW FOR PRECIP APPEARS TO OPEN FRIDAY NIGHT AS THE UPPER
CYCLONE ATTAINS A NEGATIVE TILT AND SPREADS THE RRQ OF AN UPPER
JET ACROSS THE REGION IN CONCERT WITH AMPLE HEIGHT FALLS AND A
PACIFIC FRONT. WHILE THE DETAILS CONCERNING THE EVOLUTION OF THIS
STORM SYSTEM ARE SIMILAR BETWEEN THE MODELS, THE ECMWF AND TO A
LESSER EXTENT THE CMC HAVE TRENDED MUCH FASTER AND DEEPER WITH THE
LOW THAN THE GFS BY EARLY SATURDAY. WE DID MODIFY RAIN CHANCES ON
SATURDAY TOWARD THIS FASTER THEME AS MORE OF THE GEFS MEMBERS
ALSO SUPPORT THIS THINKING OF PRECIP SHIFTING OFF THE CAPROCK BY
DAYBREAK.
A LIGHTLY UNSETTLED NORTHWEST FLOW REGIME LOOKS TO ENSUE BY THE
END OF THE WEEKEND INTO EARLY NEXT WEEK AS A SERIES MINOR TROUGHS
CREST A DEVELOPING RIDGE ACROSS THE INTERMOUNTAIN WEST, BUT THE
TIMING OF THESE WAVES IS TOO MUCH OF AN UNKNOWN THAT WE'LL REFRAIN
FROM ENTERTAINING ANY ADDITIONAL POPS PARTICULARLY SINCE PWATS
WILL BE DEPLETED TO 1/4" OR LOWER FOLLOWING FRIDAY NIGHT'S TROUGH.
TEMPS IN GENERAL LOOK TO REMAIN NEAR OR A BIT BELOW SEASONAL
NORMS WITH FORTUNATELY NO THREAT OF STRONG WINDS ANYTIME SOON.
LUB WATCHES/WARNINGS/ADVISORIES
NONE.
23
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page