417  
FXUS64 KLCH 272151  
AFDLCH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LAKE CHARLES LA  
451 PM CDT THU APR 27 2017  
   
DISCUSSION
 
 
GENERALLY PLEASANT CONDITIONS ACROSS THE AREA THIS AFTERNOON WITH  
PLENTY OF SUN AND TEMPERATURES IN THE UPPER 70S/MID 80S. WHAT  
REMAINS OF THE FRONT THAT PUSHED THROUGH THE AREA YESTERDAY IS  
ALREADY BEGINNING TO SHOW SIGNS OF RETREATING NORTHWARD THROUGH  
THE NW GULF.  
 
SOUTHERLY FLOW IS PROGGED TO RETURN TO THE AREA TONIGHT, WHICH  
WILL BEGIN THE PROCESS OF USHERING GULF MOISTURE BACK INTO THE  
REGION. THIS PROCESS WILL ACCELERATE LATE TONIGHT INTO EARLY  
FRIDAY AS THE AFOREMENTIONED WARM FRONT LIFTS NORTH THROUGH THE  
AREA, AND A DEEPER/STRONGER SOUTHERLY FETCH BECOMES ESTABLISHES  
COURTESY OF AN INITIAL LEE CYCLONE OVER THE CENTRAL/SOUTHERN  
PLAINS. SOME LIGHT SHOWER ACTIVITY IS POSSIBLE EARLY TOMORROW IN  
ASSOCIATION WITH THE RETREATING WARM FRONT, WITH A THUNDERSTORM  
OR TWO OVER EAST CENTRAL LA BY AFTERNOON. GUIDANCE OTHERWISE  
INDICATES AN UNSTABLE BUT CAPPED ATMOSPHERE WITH LITTLE IN THE WAY  
OF ANY FORCING MECHANISMS. SOUTH WINDS OVER THE COASTAL COUNTIES  
AND PARISHES WILL NEAR WIND ADVISORY CRITERIA, BUT LOOK TO  
GENERALLY REMAIN JUST BELOW. THUS, A CLOUDY, SOMEWHAT BREEZY, AND  
WARM DAY IS ON TAP.  
 
THE INITIAL LEE CYCLONE IS FORECAST TO WEAKEN AND LIFT OUT TO THE  
NE ON FRI, ONLY TO BE QUICKLY REPLACED BY ANOTHER OVER THE TX  
PANHANDLE FRI NIGHT, FURTHER STRENGTHENING LOW LEVEL WINDS FIELDS.  
WINDS ON SAT WILL ALMOST CERTAINLY EXCEED WIND ADVISORY CRITERIA,  
WITH FREQUENT GUSTS TO 35 MPH EXPECTED ALONG AND SOUTH OF THE I-10  
CORRIDOR. GLOBAL MODELS DIVERGE A BIT ON CONVECTIVE PROSPECTS SAT,  
WITH THE ECMWF AND CMC GENERATING ACTIVITY DURING THE AFTERNOON,  
AS AN APPARENT SUBTLE SHORTWAVE EJECTS OUT AHEAD OF THE MAIN UPPER  
TROF STILL PROGGED TO BE JUST EAST OF THE FOUR CORNERS. LESS  
CONVECTIVE INHIBITION AND GREATER SHEAR ARE PROGGED, SO ANY DEEP  
CONVECTION THAT CAN GET GOING WILL HAVE SOME SEVERE POTENTIAL  
DURING THE AFTERNOON/EVENING HOURS.  
 
BY THE OVERNIGHT PERIOD, AS THE UPPER TROF AND ASSOCIATED SFC LOW  
BEGIN TO LIFT OUT TWD THE E/NE, THE TRAILING CDFNT WILL PUSH INTO  
E TX ACCOMPANIED BY WIDESPREAD SHOWERS AND THUNDERSTORMS, AND  
CONTINUE EAST THROUGH LA DURING THE DAY ON SUNDAY. THERE REMAINS  
SOME SPREAD IN MODEL GUIDANCE REGARDING THE SPEED/TIMING OF THE  
FRONTAL PASSAGE, BUT THEY AREA IN GENERALLY GOOD AGREEMENT THAT  
MOST OF THE RAIN SHOULD BE EAST OF THE AREA BY SUN EVENING.  
 
WHILE MOISTURE CONTENT WILL BE IMPRESSIVE (PWATS IN EXCESS OF 2")  
THE RELATIVE SPEED OF THE SYSTEM WILL HELP MITIGATE WIDESPREAD  
FLOODING CONCERNS, THOUGH LOCALLY HEAVY RAIN IS CERTAINLY  
POSSIBLE, AND HAS BEEN ADDED TO THE GRIDDED FORECAST. DEEP  
CONVECTION IN PARTICULAR WILL BE CAPABLE OF VERY HIGH RAINFALL  
RATES. THERE WILL ALSO BE AN ACCOMPANYING SEVERE WEATHER RISK  
GIVEN FORECAST PARAMETERS, WITH ALL MODES SEEMINGLY IN PLAY.  
 
DRY AND MILD WEATHER EXPECTED IN THE WAKE OF THE FRONT SUNDAY  
NIGHT INTO TUESDAY, WITH GOOD RAIN CHANCES RETURNING MID TO LATE  
WEEK AS ANOTHER UPPER TROF TAKES AIM AT THE REGION.  
 
13  
 

 
   
MARINE
 
 
EAST WINDS WILL GRADUALLY BECOME MORE SOUTHERLY AND INCREASE  
TONIGHT AS SURFACE HIGH PRESSURE MOVES OFF TOWARD THE NORTHEAST  
AND PRESSURES FALL OVER THE CENTRAL AND SOUTHERN PLAINS. MODEST  
ONSHORE FLOW WILL CONTINUE TOMORROW, AND BECOME QUITE STRONG AND  
GUSTY FRIDAY NIGHT AND SATURDAY AS A COLD FRONT APPROACHES THE  
AREA. GUSTS IN EXCESS OF GALE FORCE ARE POSSIBLE SATURDAY AND  
SATURDAY NIGHT. THIS STRONG SOUTHERLY FLOW WILL ALSO RESULT IN  
ABOVE NORMAL TIDE READINGS THE NEXT FEW HIGH TIDE CYCLES,  
ESPECIALLY SATURDAY AND SUNDAY MORNINGS. WINDS WILL SUBSIDE AND  
BECOME NORTHWESTERLY FROM WEST TO EAST ON SUNDAY AS THE COLD FRONT  
PUSHES THROUGH THE AREA. WIDESPREAD SHOWERS AND THUNDERSTORMS ARE  
EXPECTED AHEAD OF AND ALONG THE FRONT.  
 
13  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
AEX 65 87 75 85 / 20 20 20 40  
LCH 69 85 76 82 / 20 10 20 50  
LFT 72 87 77 86 / 20 10 10 40  
BPT 70 86 77 84 / 20 10 20 50  
 

 
   
LCH WATCHES/WARNINGS/ADVISORIES
 
 
LA...NONE.  
TX...NONE.  
GM...SMALL CRAFT EXERCISE CAUTION FROM MIDNIGHT CDT TONIGHT THROUGH  
FRIDAY MORNING FOR GMZ450-452-455-470-472-475.  
 

 
 

 
 
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