FXUS64 KLCH 261029
AFDLCH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
429 AM CST THU NOV 26 2009
.DISCUSSION...
SFC OBS AND SATELLITE IMAGERY INDICATES A CRYSTAL CLEAR AND COOL
MORNING ONGOING ACROSS THE FORECAST AREA. READINGS ARE GENERALLY
IN THE UPPER 30S OVER THE NRN 1/2 OF THE AREA...LOWER 40S ALL BUT
THE IMMEDIATE COAST SRN 1/2. WATER VAPOR IMAGERY SHOWS SHORTWAVE
ROUNDING THE GREAT LAKES UPPER LOW APPROACHING THE LOWER
MISSISSIPPI VALLEY. THIS FEATURE IS PULLING A REINFORCING COOL
FRONT INTO THE REGION...AT LAST CHECK MOVING OUT OF SWRN AR AND
INTO NWRN LA PER LATEST SFC ANALYSIS.
SHOULD BE A FINE THANKSGIVING DAY ACROSS THE FORECAST AREA WITH
MOSTLY CLEAR SKIES AND COOL TEMPERATURES AS THE COOL FRONT TO OUR
NORTH SLIDES THROUGH THE REGION. LOWER DEWPOINTS BEHIND THE FRONT
WILL SET THE STAGE FOR THE COOLEST TEMPS OF THE SEASON TO DATE TO
OCCUR TONIGHT. DEWPOINTS ARE FORECAST TO RUN IN THE LOWER 30S...
LUCKILY THERE ARE A COUPLE OF FACTORS IN PLAY WHICH SHOULD KEEP
TEMPS FROM FALLING ALL THE WAY TO THE DEWPOINT AND THUS REMAINING
ABOVE FREEZING. ATTM THE CENTER OF THE SFC HIGH IS PROGGED TO
REMAIN OVER S-CNTL TX WHICH SHOULD KEEP JUST ENOUGH OF A GRADIENT
IN PLACE TO KEEP WINDS FROM GOING COMPLETELY CALM. IN ADDITION CIRRUS
SHOWING UP ON SATELLITE IMAGERY OVER THE GULF THIS MORNING WILL GRADUALLY
CREEP NWD TOWARD THE AREA WHICH MAY ALSO PROVIDE A LITTLE BIT OF A
BLANKET TONIGHT. THUS AM CURRENTLY FORECASTING MINS TONIGHT IN THE
MID TO UPPER 30S...HOWEVER WOULD NOT BE SURPRISED IF EITHER OR
BOTH OF THE PREVIOUSLY MENTIONED FACTORS DONT MATERIALIZE WHICH
WOULD ALLOW TEMPS TO FALL A LITTLE LOWER. BUT AS STATED PREVIOUSLY
WOULD EXPECT SOME FROST TO DEVELOP OVER THE NRN ZONES BY SUNRISE
FRIDAY.
FRIDAY AND FRIDAY NIGHT WILL REMAIN ON THE DRY SIDE AS THE SFC
HIGH SLIDES PAST THE AREA. SET UP OF RETURN FLOW OFF THE GULF WILL
ALLOW A WARMING TREND TO DEVELOP. INCREASING MOISTURE WILL COMBINE
WITH AN APPROACHING SHORTWAVE AND WEAK ISENTROPIC LIFT TO ALLOW
FOR THE DEVELOPMENT OF WIDELY SCATTERED SHOWERS BY SATURDAY NIGHT.
FUN PART OF THE FORECAST BEGINS SUNDAY AS STORM SYSTEM BEGINS TO
DEVELOP OVER THE 4-CORNERS REGION. INCREASING ENERGY ALOFT
EJECTING NEWD AHEAD OF THE SYSTEM WILL INDUCE A SFC LOW TO DEVELOP
OVER NERN TX WHICH WILL PULL A COLD FRONT ACROSS THE REGION
MONDAY AFTERNOON. LIFT WILL BE FURTHER INCREASED BY GOOD JET
POSITIONING ALOFT AT TIME OF FROPA. ATTM AM GOING WITH 50/50 POPS FOR
MONDAY BUT CERTAINLY RAIN CHANCES WITH THIS EVENT COULD GO HIGHER
AS WE GET CLOSER TO THE EVENT. WILL LET LATER SHIFTS BETTER REFINE
SEVERE THREAT FOR MONDAY BUT ATTM THUNDER LOOKS FAIRLY LIKELY.
BEYOND MONDAY MODEL SOLUTIONS DIFFER BY ABOUT 12 HOURS AS CUTOFF
LOW ALOFT PUSHES PAST THE REGION LIKELY PRODUCING ANOTHER ROUND OF
PRECIP. FASTER GFS BRINGS THIS FEATURE ACROSS ON TUESDAY NIGHT
WHILE SLOWER ECMWF LAGS THIS SYSTEM TIL WEDNESDAY. USED THE GFS
FOR THIS FORECAST ALTHOUGH WITH THE AMOUNT OF UNCERTAINTY INVOLVED
JUST KEPT A SMALL POP IN THE FORECAST ALL THE WAY THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.MARINE...THE COOL FRONT CROSSING THE REGION TODAY WILL INDUCE
ANOTHER ROUND OF STRONGER NRLY WINDS OVER THE COASTAL WATERS.
WINDS OVER THE OFFSHORE ZONES COULD HIT 20 KNOTS FOR A TIME THIS
AFTERNOON BUT FOR NOW HAVE ELECTED TO WORD CWF WITH 15-20 KNOTS
AND INSERT CAUTION WORDING ATTM. WINDS WILL DIMINISH BEGINNING
TONIGHT AS THE HIGH APPROACHES WITH LIGHT WINDS EXPECTED INTO THE
WEEKEND. STRONG OFFSHORE FLOW EXPECTED AGAIN LATE MONDAY WITH THE
FROPA.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 65 39 65 46 70 / 0 0 0 0 10
KBPT 65 39 66 48 71 / 0 0 0 0 10
KAEX 61 35 64 41 68 / 0 0 0 0 10
KLFT 62 37 64 43 69 / 0 0 0 0 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
25
