FXUS64 KLUB 251834
AFDLUB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
1234 PM CST FRI DEC 25 2009
.DISCUSSION...
HAVE BUMPED MAX TEMPS THIS AFTERNOON A FEW DEGREES IN MOST AREAS
BASED ON CURRENT DIURNAL TRENDS AS WELL AS INCREASED LIKELIHOOD OF
FREEZING FOG WITH THE EXCEPTION OF THE FAR SOUTHWEST WHERE SNOW
PACK IS QUICKLY VANISHING. SEE AVIATION DISCUSSION BELOW FOR
ADDITIONAL INSIGHT TO FREEZING FOG UNCERTAINTIES. 26
&&
.PREV DISCUSSION... /ISSUED 1204 PM CST FRI DEC 25 2009/
AVIATION...
CONCERN WITH THIS FCST PACKAGE FOCUSES ON THREAT FOR FREEZING
FOG THIS EVENING. WINDS WILL BE FAIRLY GENTLE THROUGH THE
PERIOD...BUT WITH THE EVAPORATION/SUBLIMATION OF THE EXISTING
SNOW PACK IN THE BDRY LAYER...MOISTURE IS EXPECTED TO INCREASE
SUBSTANTIALLY THIS AFTERNOON WITH SOME MODERATE MIXING.
HOWEVER...AS WINDS DROP OFF THIS EVENING UNDER CLEAR SKIES...EXPECT THE
BOUNDARY LAYER TO BECOME MORE STRATIFIED UNDER SUBSTANTIVE
INVERSION LEADING TO THE DEVELOPMENT OF FREEZING FOG. THUS
FAR...MODEL GUIDANCE HAS OVERDONE THE INCREASE IN SFC BASED
MOISTURE SOMEWHAT...BUT THINK THAT THIS WILL ONLY DELAY THE ONSET
A FEW HOURS. FCST CONFIDENCE OF FOG DENSITY IS LOW AND THERE IS
SOME RISK OF LIFR CONDITIONS OVERNIGHT AT BOTH TERMINALS...SO PLAN
ACCORDINGLY. HAVE HEDGED CONSERVATIVELY WITH THIS TAF ISSUANCE AND
OBSERVE MOISTURE TRENDS THIS AFTERNOON. 26
PREV DISCUSSION... /ISSUED 411 AM CST FRI DEC 25 2009/
SHORT TERM...
FRIGID TEMPERATURES THIS CHRISTMAS MORNING WILL UNDERGO GRADUAL
IMPROVEMENT THROUGHOUT THE DAY COURTESY OF AMPLE SUNSHINE...HOWEVER
AN IMPRESSIVE SNOWFIELD ALONG WITH LIGHT WESTERLY WINDS SHOULD LIMIT
LOW-LEVEL MIXING RESULTING IN MOST LOCALES SEEING JUST LOW 30S FOR
HIGHS. EXCEPTION TO THIS WILL BE IN THE EXTREME SWRN ZONES WHERE THE
SNOWPACK TERMINUS IS FOUND. MEANWHILE...DUAL UPPER LOWS IN THE MID
CONUS ARE FORECAST TO CONSOLIDATE WELL NORTHEAST OF WEST TX LATER
TODAY BEFORE THE WESTERNMOST LOW SPREADS A PV FILAMENT INTO THE SRN
PANHANDLE TONIGHT WITH PERHAPS A FEW MID LEVEL CLOUDS.
MAIN CHALLENGE HOWEVER CONCERNS THREAT FOR SOME FZFG OVERNIGHT GIVEN
A MOIST SURFACE LAYER AND LIGHT WINDS. GFS IS SUSPICIOUSLY MILD
OVERNIGHT IN SPITE OF DIMINISHED WINDS...CLEAR SKIES AND THE
RESIDENT SNOWFIELD...SO HAVE DISCARDED THIS SCENARIO IN FAVOR OF THE
NAM WHICH BETTER FITS THIS PATTERN. MULTIPLE POINT SOUNDINGS VIA THE
NAM DO REVEAL FAVORABLE HYDROLAPSE PROFILES IN THE LOWEST LEVELS AND
AMPLE SATURATION...THOUGH CALM WINDS AT TIMES MAY TEND TO OFFSET THE
FOG PROCESS RESULTING IN JUST FROST...SO FZFG MENTION WAS RESTRICTED
TO PATCHY FOR THE TIME BEING.
LONG TERM...
IT IS THE MORNING OF CHRISTMAS AND I AM BACK IN THE CHAIR
TO BRING YOU THE LONG-TERM DISCUSSION WITH A BIT OF CHRISTMAS FLAIR.
THE MAIN STORM IS PAST AND WHAT SNOW WILL REMAIN ON THE GROUND
WILL DETERMINE HOW TEMPERATURES MANAGE TO REBOUND.
THE CLOSED LOW OVER THE GREAT LAKES WILL BE SLOW TO MOVE OUT
AND NORTHWESTERLY FLOW ALOFT THROUGH LATE SATURDAY ISN/T IN DOUBT.
ALL THESE CONDITIONS TOGETHER WILL LIKELY KEEP TEMPERATURES COOL
SO GOING ON THE COLD SIDE OF MOS TEMPERATURES WILL BE THE RULE.
TEMPERATURES STAY COOL WITH MID TO UPPER 40S FOR HIGHS
AND LOWS IN THE TEENS TO NEAR 20 IS WHAT I CAN SURMISE.
ANOTHER WEAK FRONT SUNDAY KEEPS WARM AIR AT BAY
BUT CHANGES ARE ON THE HORIZON STARTING EARLY ON MONDAY.
A DEEPENING TROF IN THE WEST WILL CHANGE THE FLOW UPSTAIRS
SOUTHWESTERLY FLOW ALOFT BY LATE MONDAY IS WHAT THE NWP DECLARES.
RETURN FLOW TRIES TO SET UP AS THE TROF PUSHES EAST
AND I REMAIN UNSURE HOW MUCH MOISTURE THE GULF WILL RELEASE.
THE TIMING REMAINS SIMILAR BUT WITH A WEAKER APPROACHING TROF...
WILL IT REMAIN JUST AS WEAK OR WILL IT CUT OFF?
I HAVE MY DOUBTS BASED ON MODEL PERFORMANCES THIS LAST TIME
FEW CHANGES WERE MADE EXCEPT TO NICKLE AND DIME.
POPS REMAIN LOW FOR TUESDAY INTO MIDWEEK...
AND I WARMED TEMPERATURES A BIT AS MODELS REMAIN QUITE OBLIQUE.
SNOW COULD FALL EARLY THEN SWITCH TO A MIX OR ALL RAIN...
THE RIGHT FORECAST THIS FAR OUT REALLY IS QUITE A PAIN.
COOLER WEATHER WILL SLIDE IN AFTER THE PASSAGE OF THE STORM
BUT THE MODELS DIVERGE AFTERWORDS...THEY JUST WON/T CONFORM.
THURSDAY THE TROF AXIS IS OVER THE CENTRAL PLAINS
BUT DIFFERENCES IN SURFACE WINDS ARE CAUSING ME GREAT PAINS.
NORTHERLY IN THE EURO BUT WESTERLY IN THE OTHER TWO...
GFS AND CANADIAN FAVOR WARMER SO I WILL WAIT AND REVIEW.
ANOTHER STRONG TROF THURSDAY THE EURO IS STARTING TO MAKE...
FAVORING COOLER TEMPERATURES WHICH HOPEFULLY ISN/T A MISTAKE.
THE LAST THE DAYS OF THE FORECAST WILL BE LEFT COOL AND DRY
TO SEE HOW THE MODELS CHANGE...FLIP-FLOP...AND TRY TO COMPLY.
LITTLE SLEEP I HAVE HAD AS SHOWN BY MY RED EYES...
SO IF I HAVE LEFT SOMETHING OUT I DO APOLOGIZE.
WE STRIVE TO DO OUR BEST IN ALL THAT WE DO
EVEN THOUGH THE SCHEDULE IS STRANGE AND OUR SLEEP IS ASKEW.
FORECASTING IS FUN FOR MY FELLOW FORECASTERS AND I...
THE SHIFT WORK IS HARD WHICH I CANNOT DENY.
BUT WE ARE HERE TO SERVE YOU AND WILL CLOSE OUT AS I CITE
MERRY CHRISTMAS FROM NWS LUBBOCK AND TO ALL A GOOD NIGHT!
JORDAN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 9 39 15 41 12 / 0 0 0 0 0
TULIA 10 38 17 42 15 / 0 0 0 0 0
PLAINVIEW 10 39 15 42 16 / 0 0 0 0 0
LEVELLAND 12 40 18 45 17 / 0 0 0 0 0
LUBBOCK 13 40 17 44 19 / 0 0 0 0 0
DENVER CITY 20 44 21 47 20 / 0 0 0 0 0
BROWNFIELD 14 43 22 47 18 / 0 0 0 0 0
CHILDRESS 17 41 20 43 23 / 0 0 0 0 0
SPUR 16 43 23 46 22 / 0 0 0 0 0
ASPERMONT 20 44 26 47 22 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26/99/26
