973  
FXUS64 KLCH 290856  
AFDLCH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LAKE CHARLES LA  
356 AM CDT SAT JUL 29 2017  
   
DISCUSSION
 
 
A DIGGING UPPER LEVEL TROUGH OVER THE EASTERN US WILL SWING AN  
UNUSUAL LATE JULY "COLD FRONT" THROUGH THE AREA THIS AFTERNOON  
THROUGH TONIGHT. CONVECTION NEAR THE FRONT IS ALREADY ONGOING THIS  
MORNING ACROSS PARTS OF NORTHERN LOUISIANA INTO CENTRAL  
MISSISSIPPI AND THIS ACTIVITY WILL GRADUALLY SINK SOUTH THROUGH  
THE DAY. FORECAST SOUNDINGS FROM THE GFS, EURO AND NAM ARE  
INDICATING A MID AND UPPER LEVEL MOISTURE SURGE AS THE FRONT  
APPROACHES RESULTING IN A DRAMATIC RISE IN PRECIPITABLE WATER  
VALUES BY THIS AFTERNOON TO NEAR 2.5 INCHES. THIS COMBINED WITH  
OBSERVATIONS OF THE ONGOING CONVECTION HAS LED ME TO ADD HEAVY  
RAINFALL WORDING TO THE TEXT FORECAST PRODUCTS FOR THIS AFTERNOON  
AND TONIGHT. BROAD QPF VALUES AREN'T ALL THAT IMPRESSIVE AS THE  
ACTIVITY IS EXPECTED TO CONTINUE MOVING FROM NORTH TO SOUTH, BUT  
THE HEAVY RAINFALL COULD RESULT IN SOME MINOR STREET FLOODING IN  
THE USUAL URBAN AND POOR DRAINAGE AREAS.  
 
AS IS TYPICAL WITH SUMMER FRONTS, NO SIGNIFICANT CHANGE IN DAILY  
HIGH TEMPERATURES WILL BE REALIZED. HOWEVER, THE FRONT WILL USHER  
IN SOMEWHAT DRIER AIR DROPPING DEWPOINTS FROM THE MID TO UPPER  
70'S BACK INTO THE MORE TOLERABLE UPPER 60'S. THIS DRIER AIR MAY  
ALLOW OVERNIGHT LOWS TO DROP A FEW DEGREES WITH UPPER 60'S  
POSSIBLE ACROSS PARTS OF CENTRAL LOUISIANA AND LOWER 70'S ALONG  
THE I-10 CORRIDOR. THE COOLEST NIGHT WILL BE MONDAY MORNING.  
 
THE AIRMASS BEGINS TO MODERATE BY MONDAY AFTERNOON WITH DEWPOINTS  
SLOWLY INCREASING. LOW END RAIN CHANCES RETURN TUESDAY WITH RAIN  
CHANCES INCREASING FURTHER FOR THE SECOND HALF OF THE WEEK AS  
ANOTHER UPPER TROUGH DIGS SOUTH ACROSS THE EASTERN US. THE EURO  
GFS AND CANADIAN ALL ATTEMPT TO SWING ANOTHER FRONTAL SYSTEM  
THROUGH THE AREA NEXT WEEKEND ALTHOUGH THERE IS CONSIDERABLE  
DIFFERENCE WITH REGARDS TO STRENGTH AND TIMING. THAT SAID, THE  
SIMPLE FACT THAT ALL THREE AGREE ON WHAT WOULD BE ANOTHER  
UNSEASONABLE FRONT AT DAYS 7 AND 8 IS PRETTY IMPRESSIVE BY ITSELF.  
ANYTHING TO TAKE THE EDGE OFF THE AUGUST HEAT IS FINE BY ME.  
 
JONES  
 

 
   
MARINE
 
 
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL MOVE OVER THE  
COASTAL WATERS LATE THIS EVENING INTO EARLY SUNDAY MORNING IN  
ADVANCE OF AN APPROACHING COLD FRONT. WINDS BEHIND THE FRONT WILL  
TURN OFFSHORE SUNDAY AND MONDAY BEFORE TURNING BACK ONSHORE  
TUESDAY. RAIN CHANCES INCREASE ONCE AGAIN BY WEDNESDAY THROUGH THE  
END OF THE WEEK AS AN UPPER LEVEL TROUGH DIGS SOUTH ACROSS THE  
EASTERN US.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
AEX 90 69 90 69 / 60 20 10 10  
LCH 92 76 91 73 / 40 50 10 10  
LFT 91 74 90 72 / 60 40 10 10  
BPT 93 75 90 72 / 30 40 10 10  
 

 
   
LCH WATCHES/WARNINGS/ADVISORIES
 
 
LA...NONE.  
TX...NONE.  
GM...NONE.  

 
 

 
 
PUBLIC...66  
 
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