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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
800 PM CST MON DEC 22 2014

.DISCUSSION...
S WINDS HAVE DIMINISHED A BIT THIS EVENING TO 5-8 MPH...EXPECTED
TO DIMINISH FURTHER AFTER MIDNIGHT AS THE PRESSURE GRADIENT
RELAXES MORE WITH THE APPROACH OF THE FIRST WEAKER COLD FRONT. A
MIX OF LOW CEILINGS/PATCHY FOG...WHICH IS EXPECTED TO BECOME MORE
AREAS OF FOG AS THE NIGHT PROGRESSES OVER INLAND AREAS/NEARSHORE
WATERS AND LAKES/BAYS. WITH INCREASING POPS TOWARDS MORNING MAKES
FOR AN INTERESTING FORECAST MIXED WITH AREAS OF FOG AND RAINFALL
AFTER DAYBREAK. TEMPS WILL LIKELY ONLY FALL A FEW MORE DEGREES
BEFORE HOLDING STEADY FOR THE REMAINDER OF THE NIGHT.

DML

&&

.PREV DISCUSSION... /ISSUED 614 PM CST MON DEC 22 2014/ 

DISCUSSION...
FOR THE 00Z TAF PACKAGE.

AVIATION...
COMPLEX AVIATION FCST THE NEXT 24 HRS...WITH LOW CLOUDS AND
POSSIBLE FOG TONIGHT COUPLED WITH CONVECTION ASSOCIATED WITH
INCOMING CDFNT. IN REGARD TO THE FORMER...FAIRLY CONFIDENT IN LOW
CIGS DEVELOPING ACROSS THE AREA...THOUGH THE TIMING IS A BIT
UNCERTAIN. ALREADY AREAS OF IFR CIGS PER IR SATELLITE IMAGERY NEAR
THE COASTAL SITES...AND IN THE PROCESS OF TYPING THIS...AMDS HAVE
BEEN SENT FOR KBPT-KLCH-KARA. VSBYS ARE ALSO NOT CLEAR
CUT...THOUGH WITH WINDS ALOFT PROGGED TO REMAIN 15-25KT THROUGH
THE EVENING...THEN INCREASE TO 30KT AFTER MIDNIGHT...WIDESPREAD
DENSE FOG APPEARS UNLIKELY. IN TERMS OF CONVECTION...ISOLATED TO
SCATTERED SHOWERS ARE POSSIBLE DURING THE PRE-DAWN HOURS...BUT
THE BULK OF THE SHOWER/TSTM ACTIVITY IS EXPECTED TO HOLD OFF UNTIL
AFTER 12Z. FOR NOW...INSERTED VCTS AT THE COASTAL SITES AT
13Z...AND KAEX AT 16Z. FURTHER REFINEMENTS TO TIMING AND/OR THE
INCLUSION OF PREVAILING/TEMPO THUNDER CAN BE MADE IN SUBSEQUENT
FCSTS. 

13

PREV DISCUSSION... /ISSUED 421 PM CST MON DEC 22 2014/ 

SYNOPSIS...
LATEST UA AND WV ANALYSIS SHOWS AN UPR TROF OVER THE CNTL 
CONUS...EXTENDING S INTO TX. AT THE SFC...A WARM FRONT HAS LIFTED 
NORTH WITH GUSTY SWLY WINDS AND MUCH WARMER AND MOISTER AIR 
SPREADING OVER THE AREA. FURTHER WEST...A COLD FRONT EXTENDS SOUTH 
ACRS NRN/CNTL TX. 

24

TEMPERATURES ARE RUNNING NEARLY 20 DEGREES WARMER THAN THIS TIME 
YESTERDAY...WITH DEWPOINTS 10 TO 15 DEGREES HIGHER. SKIES HAVE 
BECOME PARTLY CLOUDY WITH AREA TEMPS APPROACHING 70 ACRS CNTL LA AND 
INTO THE MIDDLE 70S ACRS THE ACADIANA REGION. KLCH RADAR HAS BEEN 
FAIRLY QUIET FOR THE MOST PART ALTHOUGH A FEW VERY SMALL ISLTD 
SHOWERS HAVE BEEN NOTED ACRS S CNTL LA. 

DISCUSSION...
FOR TONIGHT...THE COLD FRONT TO THE WEST WILL APPROACH THE AREA. 
WITH ABUNDANT MOISTURE AHEAD OF THE FRONT...EXPECT ISLTD TO WIDELY 
SCT SHOWERS TO DEVELOP DURING THE EVENING AND OVERNIGHT. AS HAS BEEN 
THE CASE THE PAST COUPLE OF NIGHTS...THERE IS THE POTENTIAL FOR FOG 
TO DEVELOP AS WELL. CONFIDENCE NOT VERY HIGH REGARDING DENSE FOG 
POTENTIAL HOWEVER AND HAVE OPTED TO CARRY AREAS OF FOG MAINLY AFTER 
MIDNIGHT AND ALLOW FUTURE SHIFTS TO RE-ASSESS. TEMPERATURES WILL BE 
A LITTLE WARMER TONIGHT THAN LAST NIGHT WITH LOWS INTO THE MIDDLE 
50S NORTH...NEAR 60 SOUTH.  

THE UPPER TROF WILL BE SLOW TO MOVE EAST THRU WEDNESDAY AS SHORTWAVE 
ENERGY TRANSLATES SOUTHWARD ON THE BACKSIDE OF THE TROF INTO 
TX...BRINGING ABOUT A DEEPENING OF THE TROF OVER THE MIDWEST AND SRN 
PLAINS. AS THIS HAPPENS...THE SFC WAVE WILL DEVELOP OVER S TX ALONG 
THE FRONT AND MOVE QUICKLY NE TOWARD THE LA COAST DURING THE DAY
TUESDAY. LIFT ASSOCIATED WITH THE SYSTEM COMBINED WITH DEEP
MOISTURE WILL BRING ABOUT NMRS TO WIDESPREAD SHOWERS AND SCT TSTMS
DURING THE DAY TUESDAY. INSTABILITY SHOULD BECOME ADEQUATE...IN
CONCERT WITH DECENT SHEAR AND STRENGTHENING LOW LVL JET...FOR SOME
STORMS TO BECOME STRONG TO SVR DURING THE AFTN MAINLY OVER THE
SERN HALF OF THE AREA FROM APPROXIMATELY SABINE PASS NE TO
MARKSVILLE.

RAIN CHCS WILL TAPER OFF FM WEST TO EAST TUESDAY EVENING AS THE SFC 
LOW LIFTS NE...BRINGING THE COLD FRONT THROUGH THE REGION. COLDER 
AIR WILL FILTER INTO THE REGION BEHIND THE FRONT. CLOUD COVER WILL 
BE SLOW TO CLEAR ON WEDNESDAY...AND THE LACK OF INSOLATION COMBINED 
WITH COLD AIR ADVECTION WILL KEEP AFTN HIGHS ON THE COOL SIDE WITH 
TEMPS IN THE LOW TO MIDDLE 50S. CHRISTMAS DAY LOOKS TO BE QUITE NICE 
WITH CLEAR SKIES. MORNING LOWS WILL BE CHILLY WITH TEMPERATURES IN 
THE 30S...POSSIBLY FLIRTING WITH THE FREEZING MARK ACRS PORTIONS OF 
THE LAKES REGION OF SE TX INTO CNTL LA. 

THROUGH THE EXTENDED...ZONAL FLOW WILL BECOME ESTABLISHED LATE IN 
THE WEEK AS ANOTHER TROF DEEPENS OVER THE WRN CONUS. MODEL GUIDANCE 
BEGINS TO DIVERGE SOMEWHAT REGARDING THE STRENGTH/TIMING OF THE NEXT 
SHORTWAVE CROSSING THE SRN PLAINS NEXT WEEKEND. THE ECMWF/CANADIAN 
HAVE BEEN TRENDING TOWARD A MORE AMPLIFIED AND SLOWER TROF THAN THE 
GFS. LIKEWISE...RAIN CHANCES ARE A BIT MORE ROBUST PER THE EC/CMC WHILE
THE GFS IS DRIER. LEANED TOWARD THE WPC SOLUTION WHICH SHOWED SOME
PREFERENCE TOWARD THE SLOWER SOLUTIONS OF THE CANADIAN AND THE
ECMWF FOR SFC FEATURES...HOWEVER TEMPERED THE SUPERBLEND MODEL SOLUTION
POPS AS CONFIDENCE IS NOT ALL THAT GREAT DUE TO THE LACK OF MODEL
CONSISTENCY/CONTINUITY. CARRIED POPS IN THE CHC RANGE FOR SATURDAY
WHICH RAIN CHCS DECREASING SUNDAY WITH THE PASSAGE OF ANOTHER
FRONT.

24

MARINE...
A LT TO MODT ONSHORE FLOW WILL CONTINUE THROUGH TUESDAY. A COLD
FRONT WILL CROSS THE COASTAL WATERS TUESDAY AFTN WITH STRONG
OFFSHORE FLOW DEVELOPING IN ITS WAKE. SMALL CRAFT ADVISORY
CONDITIONS ARE EXPECTED TUESDAY NIGHT INTO WEDNESDAY. OFFSHORE
FLOW WILL WEAKEN BY THURSDAY WITH ONSHORE FLOW GRADUALLY
DEVELOPING BY LATE THURSDAY AS HIGH PRES MOVES EAST. ANOTHER FRONT
WILL MOVE THROUGH THE AREA NEXT WEEKEND.

24

&&

.PRELIMINARY POINT TEMPS/POPS...
KLCH  58  67  43  55  37 /  20  80  20  10  10 
KBPT  58  66  43  55  37 /  20  70  20  10  10 
KAEX  54  63  41  52  33 /  20  80  30  10  10 
KLFT  60  69  46  55  37 /  20  80  30  10  10 

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT EXERCISE CAUTION TUESDAY AFTERNOON FOR THE FOLLOWING 
     ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 
     20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA 
     OUT 20 NM...COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO 
     INTRACOASTAL CITY LA OUT 20 NM...WATERS FROM INTRACOASTAL 
     CITY TO CAMERON LA FROM 20 TO 60 NM...WATERS FROM CAMERON 
     LA TO HIGH ISLAND TX FROM 20 TO 60 NM...WATERS FROM LOWER 
     ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM. 

&&

$$

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