459  
FXUS64 KLIX 181118  
AFDLIX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NEW ORLEANS LA  
618 AM CDT THU JUN 18 2026  
   
..NEW AVIATION
 
 
   
KEY MESSAGES
 
 
UPDATED AT 613 AM CDT THU JUN 18 2026  
 
- POTENTIAL FOR LIFE THREATENING FLASH FLOODING. A PARTICULARLY  
DANGEROUS AND LIFE THREATENING FLASH FLOOD SITUATION EXISTS WITH  
A HIGH RISK OF FLOODING ACROSS PORTIONS OF SOUTH MISSISSIPPI AND  
SOUTHEAST LOUISIANA, ESPECIALLY EAST OF INTERSTATE 55.  
CONSIDERABLE FLASH FLOODING IS LIKELY AND CATASTROPHIC FLASH  
FLOODING IS POSSIBLE TODAY.  
 
- A FLOOD WATCH IS IN EFFECT THROUGH FRIDAY MORNING FOR MOST OF  
SOUTHEAST LOUISIANA AS WELL AS ALL OF SOUTHWEST AND COASTAL  
MISSISSIPPI.  
 
- TORNADO WATCH 348 IN EFFECT UNTIL 6 AM CDT FOR MOST OF THE AREA.  
 
- DANGEROUS CONDITIONS FOR MARINERS OF SMALL CRAFT AND MINOR  
COASTAL FLOODING ON SOUTH FACING SHORES WEST OF THE MISSISSIPPI  
RIVER WILL PERSIST THROUGH TONIGHT AS POST TROPICAL CYCLONE  
ARTHUR MOVES INTO SOUTHWEST LOUISIANA.  
 
- EXTREME HEAT IS EXPECTED THIS WEEKEND. HEAT ADVISORIES WILL  
LIKELY BE ISSUED FOR HEAT INDEX VALUES OF AROUND 110 DEGREES.  
 

 
   
UPDATE
 
 
ISSUED AT 354 AM CDT THU JUN 18 2026  
 
UPDATED KEY MESSAGES FOR WPC'S HIGH RISK OF EXCESSIVE RAINFALL  
TODAY FOR PORTIONS OF THE AREA. LIKELY TO HAVE A FAIRLY LARGE  
STRIPE OF 6 TO 10 INCH RAINFALL WITH ISOLATED TOTALS SIGNIFICANTLY  
HIGHER FROM HOUMA AND THIBODAUX NORTHEASTWARD.  
 

 
   
SHORT TERM
 
 
(NOW THROUGH SUNDAY)  
ISSUED AT 1220 AM CDT THU JUN 18 2026  
 
POST TROPICAL CYCLONE ARTHUR HAS DEGENERATED TO A LOW PRESSURE  
AREA ALONG THE UPPER TEXAS COAST. THE REMNANTS WILL CONTINUE TO  
TRACK ACROSS WESTERN LOUISIANA OVERNIGHT AND WILL REACH THE  
CAROLINAS COASTLINES BY FRIDAY MORNING. WE'VE ALREADY SEEN SOME  
ROTATION IN RADAR DATA, AND EXPECT WE'LL HAVE SHORT-LIVED SPINUPS  
OVERNIGHT. ADDITIONALLY, WE REMAIN HIGHLY CONCERNED ABOUT EXTREME  
RAINFALL AMOUNTS OVERNIGHT. WE ALREADY HAD 2.3 INCH PRECIPITABLE  
WATER VALUES AT 00Z, WITH GUIDANCE INDICATING THAT VALUES NEAR 2.6  
INCHES ARE POSSIBLE/LIKELY OVERNIGHT AS A 35-40 KNOT LOW LEVEL JET  
PLUGS IN. THE 02Z HRRR, FOR INSTANCE, HAS A LARGE AREA OF RAINFALL  
TOTALS IN EXCESS OF 6 INCHES ACROSS THE AREA BY MID-AFTERNOON  
THURSDAY WITH SPOT TOTALS APPROACHING OR EXCEEDING 10 INCHES. IF  
THESE TOTALS, OR ANYTHING CLOSE ARE REALIZED, WE'RE PROBABLY  
LOOKING AT MAJOR FLOODING IN THOSE AREAS. NO CHANGES TO FLOOD  
WATCH ANTICIPATED. COULD STILL BE SCATTERED PRECIPITATION INTO  
THURSDAY EVENING ASSOCIATED WITH THIS SYSTEM BEFORE WE START  
SEEING SOME SLIGHT DRYING.  
 
WITH PRECIPITABLE WATER VALUES REMAINING NEAR 2 INCHES THROUGH  
SUNDAY, STILL PLENTY OF MOISTURE AVAILABLE FOR SCATTERED  
CONVECTION, EVEN WITHOUT LARGE SCALE FORCING TO AID IN PRODUCING  
LIFT. THE LARGE SCALE HEAVY RAINFALL THREAT WILL DIMINISH BEYOND  
THURSDAY EVENING, BUT LOCALIZED HEAVY RAIN STILL POSSIBLE. COULD  
ALSO SEE A FEW MICROBURSTS ON FRIDAY.  
 
A SECOND ISSUE OVER THE WEEKEND WILL BE HEAT STRESS. WE'LL LIKELY  
SEE AT LEAST SOME SUNSHINE AT TIMES FRIDAY THROUGH THE WEEKEND  
THAT WILL ALLOW TEMPERATURES TO GET INTO THE LOWER, OR POSSIBLY  
MIDDLE 90S IN MANY AREAS. WITH DEW POINTS LIKELY IN THE UPPER 70S  
TO NEAR 80, AND LOTS OF RESIDUAL MOISTURE ON THE GROUND, IT'S  
GOING TO BE STEAMY. LIKELY TO HAVE HEAT INDEX VALUES NEAR OUR 108  
DEGREE CRITERIA FOR HEAT ADVISORIES IN MANY AREAS ON FRIDAY AND  
POSSIBLY AGAIN ON SUNDAY. THIS WILL BE ADDRESSED ONCE WE GET PAST  
THE RAINFALL AND TORNADO ISSUES THIS MORNING. OVERNIGHT LOWS MAY  
HAVE TROUBLE GETTING BELOW 80 DEGREES FOR SEVERAL NIGHTS.  
 

 
   
LONG TERM
 
 
(SUNDAY NIGHT THROUGH WEDNESDAY)  
ISSUED AT 1220 AM CDT THU JUN 18 2026  
 
RIDGING SETS UP OVER THE NORTHERN GULF FOR THE FIRST HALF OF NEXT  
WEEK. HOWEVER, SHORTWAVES WILL BE TRACKING WEST TO EAST JUST NORTH  
OF THE LOCAL AREA. IF WE ARE GOING TO HAVE A DAY THAT IS  
COMPLETELY DRY, IT'LL PROBABLY BE MONDAY. SIMILAR TO THE WEEKEND,  
WE'LL HAVE TO MONITOR FOR POTENTIAL HEAT ADVISORIES, ESPECIALLY  
MONDAY. FOR TUESDAY AND WEDNESDAY, THE QUESTION WILL BE EXACTLY  
WHEN STORMS DEVELOP. IF THEY DEVELOP EARLY ENOUGH IN THE DAY, THAT  
WOULD BLUNT THE HEAT SOMEWHAT. FOR NOW, WILL STICK WITH THE NBM  
FORECAST TEMPERATURES WITH SEVERAL DAYS SEEING HIGHS IN THE LOWER  
AND MIDDLE 90S.  
 

 
   
AVIATION
 
 
(12Z TAFS)  
ISSUED AT 613 AM CDT THU JUN 18 2026  
 
LARGE AREA OF SHRA/TSRA MOVING ACROSS MOST TERMINALS EARLY THIS  
MORNING WITH IFR OR LOWER CONDITIONS. MAIN EXCEPTIONS ARE KHUM AND  
KBTR, WHERE CONVECTION HAS MOVED EAST FOR NOW. EASTERN TERMINALS  
COULD STILL SEE GUSTS TO AROUND 40 KNOTS AS CONVECTION MOVES  
THROUGH. THE CURRENT AREA OF CONVECTION SHOULD BE EAST OF ALL  
TERMINALS BY 18Z, BUT WITH ABUNDANT MOISTURE STILL IN PLACE,  
AFTERNOON HEATING COULD REDEVELOP TSRA. EXPECT ANY REMAINING  
PRECIPITATION TO DISSIPATE AFTER SUNSET, BUT MVFR CEILINGS COULD  
REDEVELOP BEFORE SUNRISE.  
 

 
   
MARINE
 
 
ISSUED AT 1220 AM CDT THU JUN 18 2026  
 
STRONG SOUTHERLY WINDS OF 20 TO 25 KNOTS WITH GUSTS OF 30 KNOTS  
WILL REMAIN IN PLACE OVER THE COASTAL WATERS THROUGH TONIGHT AND  
INTO THURSDAY AND SEAS OF 6 TO 9 FEET CAN BE EXPECTED IN THE OPEN  
GULF WATERS. SMALL CRAFT ADVISORIES REMAIN IN EFFECT DUE TO THESE  
CONDITIONS. MOVING INTO THE WEEKEND AND EARLY NEXT WEEK, A BROAD  
AREA OF HIGH PRESSURE WILL BUILD BACK OVER THE EASTERN GULF  
WATERS. PERSISTENT ONSHORE WINDS OF 10 TO 15 KNOTS AND SEAS OF 2  
TO 4 FEET CAN BE EXPECTED FROM FRIDAY THROUGH EARLY NEXT WEEK.  
 

 
   
LIX WATCHES/WARNINGS/ADVISORIES
 
 
LA...FLOOD WATCH THROUGH FRIDAY MORNING FOR LAZ034>037-039-046>048-  
056>058-064-071-076>087-089-090-092-094-096-098>100.  
 
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CDT FRIDAY FOR GMZ529-531>536-  
541-543-551-553-554-557-570-572-575-577.  
 
MS...FLOOD WATCH THROUGH FRIDAY MORNING FOR MSZ068>071-077-083>088.  
 
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CDT FRIDAY FOR GMZ531>536-541-  
543-551-553-554-557-570-572-575-577.  
 

 
 

 
 
SHORT TERM...RW  
LONG TERM....RW  
AVIATION...RW  
MARINE...RW  
 
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