478  
FXUS64 KLCH 292223  
AFDLCH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LAKE CHARLES LA  
423 PM CST SUN JAN 29 2023  
   
..NEW SYNOPSIS, SHORT TERM, LONG TERM, MARINE
 
 
   
SYNOPSIS
 
 
ISSUED AT 336 PM CST SUN JAN 29 2023  
 
COPIOUS MOISTURE STREAMING OVER THE REGION, COMBINED WITH  
ISENTROPIC LIFT ATOP A WEAK BOUNDARY ALONG THE I-10 CORRIDOR IS  
PRODUCING SCATTERED TO NUMEROUS SHOWERS AND A FEW STORMS ALONG  
AND NORTH OF THIS ZONE. RADAR ESTIMATED RAINFALL TOTALS SUGGEST  
FROM ONE HALF TO 2 INCHES OF RAIN HAVE FALLEN ACROSS MUCH OF THE  
AREA, ALTHOUGH A FEW BANDS OF 2 TO 3 INCHES TOTALS ARE SEEN ACROSS  
PORTIONS OF SW AND S CNTL LA. WHILE SOME POCKETS OF HEAVIER  
RAINFALL HAVE BEEN NOTED, FLASH DATA HAS NOT SIGNIFICANTLY  
INCREASED SINCE THIS MORNING, AND OVERALL FLOOD CONCERNS HAVE BEEN  
MINIMAL.  
 
24  
 

 
   
SHORT TERM
 
 
(TONIGHT THROUGH TUESDAY NIGHT)  
ISSUED AT 336 PM CST SUN JAN 29 2023  
 
RECENT CAMS SHOW A GENERALLY DECREASING TREND IN CONVECTION  
TONIGHT, BUT A FEW MORE CLUSTERS OF HEAVIER SHOWERS WILL STILL BE  
POSSIBLE AND WITH SATURATED SOILS ACROSS THE REGION, THE RISK FOR  
FLOODING WILL CONTINUE UNTIL ACTIVITY DIMINISHES/WEAKENS.  
THEREFORE, WILL MAINTAIN THE FLOOD WATCH THROUGH THIS EVENING.  
 
GUIDANCE SHOWS HIGHER PWATS AND DEEPER MOISTURE EXITING EAST  
TONIGHT WHILE A WEAK COOL FRONT SLIDES SOUTH INTO THE REGION,  
EVENTUALLY STALLING ACRS S CNTL LA SOUTHWESTWARD ACROSS THE  
COASTAL WATERS. MODEST FORCING ALONG THE FRONT WILL MAINTAIN A LOW  
CHANCE FOR RAIN MONDAY.  
 
AS THIS RAIN EVENT WINDS DOWN, CONCERNS WILL SHIFT TOWARD THE  
POTENTIAL FOR FOG TONIGHT, AND POSSIBLY OVER THE NEXT FEW DAYS AS  
WELL. A SATURATED AND INCREASINGLY STABLE NEAR SURFACE AIRMASS,  
ALONG WITH WEAK TO NEAR CALM WINDS, WILL PROVIDE FAVORABLE  
CONDITIONS FOR FOG FORMATION OVERNIGHT. GUIDANCE HINTS AT  
VISIBILITIES LESS THAN A MILE ACROSS SOUTHERN PORTIONS OF THE AREA  
(I-10 SOUTHWARD) AND THIS WILL NEED TO BE MONITORED FOR POSSIBLE  
DENSE FOG ADVISORIES LATER AS CONFIDENCE ON TIMING AND COVERAGE  
ARE CURRENTLY LOW.  
 
AN ACTIVE PATTERN WILL PERSIST THROUGH MIDWEEK, AS A LONGWAVE  
TROUGH/LOW MEANDERS NEAR THE BAJA AND INTERMITTENT IMPULSES EJECT  
INTO THE SOUTHWESTERLY FLOW ALOFT. ANOTHER ROUND OF CONVECTION  
IS EXPECTED TO DEVELOP ACROSS TX MONDAY NIGHT AND SPREAD INTO THE  
AREA THROUGH TUESDAY.  
 
TEMPERATURES TONIGHT INTO MONDAY WILL BE GOVERNED BY THE PROGRESS  
OF THE FRONTAL BOUNDARY, WHICH IS EXPECTED TO STRETCH FROM ROUGHLY  
NATCHEZ MS TO CAMERON LA BY EARLY MONDAY. AHEAD OF THE BOUNDARY,  
TEMPERATURES WILL REMAIN IN THE 60S OVERNIGHT, WHILE THE COOLEST  
TEMPERATURES WILL STAY BACK TO THE NW ACROSS INTERIOR SE TX, WHERE  
LOWS ARE EXPECTED TO FALL TO AROUND 50 DEGREES. A SIMILAR  
DISTRIBUTION IS EXPECTED ON MONDAY, WITH HIGHS RANGING FROM THE  
UPPER 50S NEAR THE LAKES REGION OF SE TX TO THE LOWER 70S ACROSS  
ACADIANA WHERE THE FRONT WILL BE VERY SLOW TO EXIT OFF THE COAST.  
TEMPERATURES WILL GRADUALLY LOWER TO NEAR SEASONAL VALUES (PLUS OR  
MINUS A FEW DEGREES) BY TUESDAY AS NORTHERLY WINDS BRING A COOLER  
AIRMASS INTO THE AREA.  
 
24  
 

 
   
LONG TERM
 
 
(WEDNESDAY THROUGH NEXT SATURDAY)  
ISSUED AT 336 PM CST SUN JAN 29 2023  
 
AS WE START THE LONG-TERM PORTION OF THE FORECAST PERIOD, OUR OLD  
FRONTAL FEATURE IS PROGGED TO STILL BE HANGING AROUND OVER THE  
COASTAL WATERS WHILE SFC HIGH PRESSURE WILL BE CENTERED OVER THE  
OHIO VALLEY AND RIDGING SWWD OVER THE FORECAST AREA. MEANWHILE, AS  
THE NEXT PACIFIC STORM SYSTEM GRADUALLY CROSSES THE SWRN CONUS, THE  
FLOW ALOFT WILL BE TURNING MORE SWRLY, WITH THE DEVELOPING  
OVERRUNNING PATTERN AND LINGERING MOISTURE MAINTAINING CLOUDY/DREARY  
CONDITIONS OVER THE FORECAST AREA. ADD TO IT ANOTHER DISTURBANCE  
CAUGHT IN THE MID-LEVEL FLOW ALOFT AND ITS ASSOCIATED INCREASING  
LIFT, ELEVATED RAIN CHANCES WILL CONTINUE FOR AT LEAST THE NWRN 1/4  
OF THE FORECAST AREA (WHERE LIFT LOOKS TO BE MAXIMIZED) INTO  
WEDNESDAY EVENING. RAIN CHANCES THEN FURTHER INCREASE AND SPREAD  
ACROSS THE REMAINDER OF THE FORECAST AREA WEDNESDAY NIGHT INTO  
THURSDAY AS THE SYSTEM CONTINUES TO FILL/EJECT ENEWD. THIS FEATURE  
SHOULD HELP INITIATE SFC LOW DEVELOPMENT OVER THE NWRN GULF...WITH  
THE LOW THEN EXPECTED TO LIFT NEWD TOWARD THE FORECAST AREA, HELPING  
ENHANCE LIFT OVER THE REGION.  
 
FORECAST SOUNDINGS INDICATE PWAT VALUES INCREASING AGAIN TO AROUND  
1.7 INCHES (WELL ABOVE THE 90TH PERCENTILE PER SPC SOUNDING CLIMO)  
AS MOISTURE CONTINUES TO STREAM OVERHEAD FROM THE GULF. WITH THE  
ADDITIONAL RAINFALL (MEAN AREAL QPFS RANGING FROM 1/2 TO 1 INCH) ON  
TOP OF ALREADY WET SOILS, THE WRN 1/2 OF THE FORECAST AREA HAS BEEN  
PLACED IN A MARGINAL RISK (DAY 4 STILL EXPERIMENTAL) FOR EXCESSIVE  
RAINFALL FOR THE WEDNESDAY/WEDNESDAY NIGHT PERIOD BY WPC. THEN  
MOVING INTO THURSDAY, WITH MUCH OF THE FORECAST AREA PROGGED TO GET,  
ON AVERAGE, AROUND ANOTHER INCH, WHICH HAS LED WPC TO INCLUDE THE  
BULK OF THE AREA IN A MARGINAL RISK FOR THURSDAY, WITH THE EXTREME  
NRN AREAS IN A SLIGHT RISK.  
 
AS THE DAMPENING SHORTWAVE/ASSOCIATED SFC LOW PUSH EWD, PRECIP  
SHOULD END FROM WEST TO EAST BY THURSDAY NIGHT, LEAVING BEHIND A  
DRIER REMAINDER OF THE FORECAST PERIOD. A BRIEF SHOT OF CAA BEHIND  
THE DEPARTING LOW WILL USHER IN COOLER CONDITIONS FOR FRIDAY/FRIDAY  
NIGHT BEFORE HIGH PRESSURE BUILDS PAST THE REGION, WITH THE  
DEVELOPING SRLY FLOW ALLOWING FOR A MODERATION OF TEMPS THROUGH THE  
WEEKEND.  
 
25  
 

 
   
AVIATION
 
 
(18Z TAFS)  
ISSUED AT 1029 AM CST SUN JAN 29 2023  
 
POOR FLYING CONDITIONS WILL PERSIST THROUGH THE PERIOD AS  
WIDESPREAD SHRA/TSRA CONTINUE OVER THE REGION BEFORE DIMINISHING  
DURING THE EVENING AND OVERNIGHT. CIGS WILL WILL LIKELY VARY  
BETWEEN MVFR AND IFR LEVELS THROUGH THE AFTERNOON, BEFORE SETTLING  
INTO IFR CATEGORIES THIS EVENING. CONVECTION WILL GRADUALLY  
DIMINISH BY 06Z TONIGHT, WHILE A WEAK FRONTAL BOUNDARY WILL SLIDE  
SOUTHWARD TONIGHT, STALLING ACROSS SOUTHERN LA. THIS WILL RESULT  
IN LIGHT/VARIABLE OR NEAR CALM WINDS, AND COMBINED WITH A NEAR  
SATURATED SURFACE LAYER, WILL LEAD TO THE POTENTIAL FOR WIDESPREAD  
LIFR CIGS AS WELL AS IFR/LIFR VISBY REDUCTIONS IN FOG.  
 
24  
 

 
   
MARINE
 
 
ISSUED AT 336 PM CST SUN JAN 29 2023  
 
A LIGHT TO MODERATE ONSHORE FLOW WILL GRADUALLY SHIFT EAST TO  
NORTHEAST LATE TONIGHT INTO MONDAY AS A COLD FRONT MOVES INTO THE  
AREA. A FEW SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE ALONG THE  
FRONT. MEANWHILE, THE RISK FOR SEA FOG WILL INCREASE, ESPECIALLY  
OVER THE NEARSHORE WATERS AND LAKES AND BAYS TONIGHT AS A  
SATURATED AIRMASS MOVES OVER RELATIVELY COOLER SHELF WATERS.  
 
A DENSE FOG ADVISORY HAS BEEN ISSUED FOR THE NEARSHORE WATERS AND  
COASTAL LAKES AND BAYS AS SEVERAL MEMBERS OF GUIDANCE HAVE SHOWN A  
SIGNAL FOR VISIBILITIES LESS THAN ONE MILE. NBM ALSO SHOWS UP TO  
A 40 PERCENT PROBABILITY OF VISIBILITIES LESS THAN ONE MILE AS  
WELL, LENDING DECENT CONFIDENCE TO THE FORECAST. PERIODS OF SEA  
FOG WILL BE POSSIBLE OVER THE NEXT FEW DAYS AS THE WEAK FRONT  
MEANDERS NEAR THE COAST.  
 
WINDS WILL GRADUALLY TURN MORE ONSHORE WEDNESDAY NIGHT AS ANOTHER  
FRONT FORMS OVER THE SOUTHERN PLAINS. THIS FRONT WILL MOVE  
THROUGH THE AREA ON THURSDAY, ACCOMPANIED BY ANOTHER ROUND OF SHOWERS  
AND STORMS. IN THE WAKE OF THE FRONT, WINDS WILL SHIFT OFFSHORE  
AND STRENGTHEN.  
 
24  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
AEX 56 63 46 53 / 80 20 20 40  
LCH 59 68 55 63 / 50 20 20 30  
LFT 64 72 57 66 / 60 30 10 20  
BPT 57 65 55 63 / 60 20 20 40  
 

 
   
LCH WATCHES/WARNINGS/ADVISORIES
 
 
LA...FLOOD WATCH UNTIL MIDNIGHT CST TONIGHT FOR LAZ027>033-041>045-  
052-073-074.  
 
TX...FLOOD WATCH UNTIL MIDNIGHT CST TONIGHT FOR TXZ180-201-215-216-  
259>262.  
 
GM...DENSE FOG ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM CST MONDAY FOR  
GMZ430-432-435-450-452-455.  
 

 
 

 
 
SHORT TERM...24  
LONG TERM....25  
AVIATION...24  
 
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