561  
FXUS64 KLIX 100222  
AFDLIX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NEW ORLEANS LA  
922 PM CDT TUE AUG 9 2022  
   
UPDATE
 
 
MADE A FEW CHANGES TO THE FORECAST THIS EVENING AS A PERSISTENT  
AREA OF SHOWERS AND THUNDERSTORMS HAS ENTERED THE FORECAST AREA  
FROM THE NORTH AFFECTING THE NORTHWESTERN PORTIONS OF THE AREA.  
INCREASED RAIN CHANCES THROUGH THE NEXT SEVERAL HOURS AND  
REFRESHED THINGS A BIT AS WELL. WHILE THE AFOREMENTIONED SHOWERS  
AND THUNDERSTORMS SEEM TO BE WANING A BIT OVERALL IN INTENSITY,  
WILL BE MONITORING THE RAINFALL AMOUNTS AS THEY ARE MOVING FAIRLY  
SLOWLY.  
   
PREV DISCUSSION
 
/ISSUED 520 PM CDT TUE AUG 9 2022/  
 
SHORT TERM...ACTIVE DAY TODAY BUT DIDN'T QUITE SEEM AS ACTIVE AS  
YESTERDAY HOWEVER, STORMS MAY PERSIST LONGER INTO THE EVENING THAN  
PREVIOUS DAYS AS WE SEEM TO BE IN MORE OF A TROPICAL LIKE  
ENVIRONMENT LEADING TO AN INCREASE IN THE OCCURRENCE OF NOCTURNAL  
CONVECTION. THIS NOCTURNAL CONVECTION USUALLY MEANS CONVECTION  
CONTRACTS TOWARDS THE CENTER OF THE DISTURBANCE AND THAT COULD BE  
WELL WHAT HAPPENS TONIGHT. THE TROPICAL WAVE LEADING TO OUR STORMS  
IS NOW OVER COASTAL LA AND COASTAL MS WITH VERY BROAD ROTATION  
NEAR THE BRETON AND CHANDELEUR SOUNDS. THIS COULD CAUSE CONVECTION  
TO CONTRACT BACK CLOSER TOWARDS THE COAST OVERNIGHT AND COULD BE  
HEAVY AT TIMES.  
 
SO OVER THE NEXT 2 DAYS AND MAYBE EVEN FRIDAY WE WILL SEE ADDITIONAL  
HEAVY RAIN BUT IT MAY BE A LITTLE MORE WIDESPREAD AS WE WILL HAVE  
MULTIPLE FEATURES COMING TOGETHER. FIRST IS THE TROPICAL WAVE WE  
ARE CURRENTLY BEING IMPACTED BY AND THE WEAKENING TUTT MOVING  
ACROSS THE NORTHERN GULF. THE TUTT WILL BECOME LESS DEFINED OVER  
THE NEXT 24 HRS AS THE NORTHERN STREAM L/W TROUGH DIGS ACROSS THE  
APPALACHIANS AND A S/W UPSTREAM CONTINUES TO BREAK DOWN THE RIDGE  
AND MOVE INTO THE LOWER MS VALLEY. THIS WILL LEAD TO A FULL BLOWN  
TROUGH AXIS SETTING UP RIGHT ALONG THE WESTERN FRINGES OF OUR  
CWA. THERE IS ANOTHER TROPICAL WAVE MOVING THROUGH THE WESTERN  
CARIBBEAN AND IT APPEARS A PIECE OF IT BROKE OFF THE NORTHERN SIDE  
AND SURGED NORTHWEST THROUGH THE FLORIDA STRAITS THIS MORNING AND  
CONTINUED TO FLY ACROSS THE SOUTHEASTERN GULF. IF THERE IS STILL  
ANYTHING LEFT TO THAT IT COULD JUST ADD MORE LIFT AND LOW LEVEL  
MOISTURE TO THE AREA TOMORROW, LEADING TO BOTH WIDESPREAD  
CONVECTION AND STRONGER MORE EFFICIENT STORMS. LUCKILY RAIN DID  
NOT OVERACHIEVE OR AT LEAST WASN'T AS HEAVY WIDESPREAD. THAT SAID,  
SOME LOCATIONS STILL SAW NEAR 4" AND THERE WAS FLOODING AROUND  
HARAHAN. THIS IS ONLY AN EXAMPLE OF WHAT WE COULD SEE OVER THE  
NEXT FEW DAYS AND POSSIBLY OVER A LARGER AREA. BACK TO THE  
EFFICIENCY OF STORMS, PWS WILL MAY BE EVEN HIGHER TOMORROW WITH  
MODELS SUGGESTING PWS POSSIBLY APPROACHING 2.5", AND H85 THETA E  
AIR OF AROUND 340K MOVING INTO THE REGION. THE K INDEX COULD  
RANGE FROM 35-40C AND WILL ALSO BE MOVING INTO THE AREA (VALUES  
ABV 35 AND CLOSER TO 40 USUALLY INDICATE A HIGHER POTENTIAL FOR  
HEAVY RAIN). INSTABILITY WILL BE IN PLACE AS WELL SO MORE  
THUNDERSTORM THAN SHOWER WHICH WILL ALSO CONTRIBUTE TO THE HEAVY  
RAIN THREAT.  
 
NOW THERE ARE SOME NEGATIVES AND IT DOES LOOK LIKE THESE COULD BE  
EASILY OVERCOME BUT IT STILL WILL HAVE SOME NEGATIVE INFLUENCE ON  
HEAVY RAIN POTENTIAL. FIRST IS NO REAL STRONG SIGNAL OF LL  
CONVERGENCE. YES LL MOISTURE WILL MOVE IN AND INCREASE BUT THERE IS  
NOT A REAL STRONG DELINEATION AND JUST A GRADUAL INCREASE. (THE  
LL CONVERGENCE ON THURSDAY THOUGH WILL BE IN PLACE). SECOND, THERE  
ISN'T ANY STRONG SIGNAL OF UPPER LEVEL DIVERGENCE. LOOKING AT  
SATELLITE THERE IS BETTER DIVERGENCE OVER THE CENTRAL AND EASTERN  
GULF BUT IT DOENS'T LOOK LIKE THAT WILL MOVE NORTH, YET. BOTH OF  
THESE ARE GENERALLY FEATURES THAT WILL ENHANCE THE HEAVY RAIN  
POTENTIAL BUT GIVEN ALL OF THE OTHER FEATURES AND HOW EFFICIENT  
RAIN HAS BEEN ALREADY SUGGESTS LOCALLY HEAVY RAIN IS LIKELY. AS  
FOR A FLASH FLOOD WATCH WE WILL HOLD OFF RIGHT NOW MAINLY BECAUSE  
WE LACKED WIDESPREAD HEAVY RAINFALL TODAY AND ALL OF THE RIVERS  
ARE STILL FAIRLY LOW. THIS SHOULD PROVIDE ENOUGH STORAGE AND  
POTENTIAL TO KEEP THINGS UNDER CONTROL FOR MOST OF THE AREA. NOW  
UNDERSTAND THAT ANY OF THE POPULATION CENTERS IT DOESN'T MATTER IF  
IT RAINED TODAY, LAST WEEK, OR LAST YEAR, IT ONLY TAKE THE RIGHT  
STORM OR STORMS TO SIT OVER THESE AREAS JUST LONG ENOUGH TO  
QUICKLY LEAD TO WATER COLLECTING AND FLOODING THE TYPICAL LOW  
LYING AREAS.  
 
THURSDAY IS STILL THE GREATEST CONCERN BECAUSE NOW IT LOOKS LIKE WE  
WILL HAVE SOME LOW LEVEL SUPPORT/FOCUS AS A BOUNDARY THAT IS  
CURRENTLY DRAPED ACROSS THE SOUTHERN PLAINS, MID MS VALLEY, AND OH  
VALLEY GETS ANOTHER PUSH TOMORROW AND THURSDAY AND IS EXPECTED TO  
MOVE INTO THE AREA. ALL OTHER INGREDIENTS WE HAVE IN PLACE  
TOMORROW WILL STILL BE IN PLACE THURSDAY FOR THE MOST PART AND  
EVEN THOUGH UPPER LEVEL DIVERGENCE ISN'T GREAT, THERE IS A HINT  
IT COULD IMPROVE JUST ENOUGH AS OTHER UPPER LEVEL FEATURES MOVE  
INTO PLACE AND JUST LEADING TO BETTER DIVERGENCE BY DEFAULT. THIS  
WILL ONLY INCREASE THE RISK FOR HEAVY RAIN AND POSSIBLY MORE  
WIDESPREAD. CAMS ARE STARTING TO FINALLY COME INTO THE TIME FRAME  
AND ARE SHOWING THE POTENTIAL FOR HEAVY RAIN AS WELL. DON'T TAKE  
THE LOCATION FOR GOSPEL HOWEVER LOOKING AT THE CAMS AS A BAROMETER  
FOR POTENTIAL WIDESPREAD 2-4 INCHES WITH LOCALLY HIGHER VALUES  
GREATER THAN 7 INCHES ARE BEING ADVERTISED OVER THE NEXT 48 HRS.  
SO THE POTENTIAL IS THERE JUST NOT QUITE CONFIDENT ENOUGH OF A  
LOCATION BUT IT APPEARS THE GREATEST THREAT FOR FLASH FLOODING  
POTENTIAL WOULD BE SOUTH OF THE MS BORDER DOWN AND ALONG I-10 AND  
EAST ACROSS COASTAL MS. THERE IS A GOOD CHANCE SOME BAND DEVELOPS  
AND TRAINS OVER AN AREA ESPECIALLY THURSDAY AND WHERE THAT OCCURS  
WILL LIKELY HAVE THE GREATEST IMPACT. IF WE GET A LARGE AREA OF  
HEAVY RAIN TOMORROW THEN WE WILL LIKELY NEED A FLASH FLOOD WATCH  
FOR PORTIONS OF THE AREA THURSDAY, MAYBE AS EARLY AS WEDNESDAY  
NIGHT.  
 
FRIDAY MODELS HAVE EVOLVED A LITTLE NOW INDICATING THAT THE RIDGE  
WILL WILL BEGIN TO PINCH THE BOTTOM OF THE L/W TROUGH AND COULD  
BREAK OFF A PIECE AT THE BASE LEADING TO A MID LEVEL CUTOFF LOW OR  
ANOTHER TUTT SITTING OVER THE AREA FRIDAY. THAT WOULD STILL INDICATE  
NUMEROUS SHOWERS AND THUNDERSTORMS MOST OF THE DAY BUT THE OLD  
BOUNDARY WILL CONTINUE TO SLOWLY WORK SOUTH AS IT TRIES TO MODIFY.  
DUE TO THE SLOWER MOVEMENT WE WOULDN'T LIKELY SEE A MORE PRONOUNCED  
AIRMASS SHIFT TILL THIS WEEKEND. /CAB/  
 
LONG TERM...  
 
MEDIUM RANGE GUIDANCE AGREE THAT BY SATURDAY, THE TUTT LOW WOULD BE  
OUT OF THE AREA AND INTO TEXAS. THIS WOULD GIVE WAY TO NORTHERLY MID  
TO UPPER LEVEL FLOW GIVEN THE POSITION OF THE H5 RIDGE OVER THE  
CENTRAL PLAINS. GENERALLY, WITH THE NORTHERLY FLOW, THIS WILL BRING  
DRIER AIR INTO THE MID AND UPPER LEVELS, CAUSING STORM DEVELOPMENT  
TO BE LATER IN THE AFTERNOON. THIS WILL ALLOW MORE DAYTIME HEATING  
AND A RISE IN MAXIMUM TEMPERATURES EACH DAY. ON THE OTHER HAND, THE  
HEATING WILL ALSO INCREASE INSTABILITY. SINCE THE MID LEVEL DRY AIR  
WILL BE IN PLACE, THE STRONGER STORMS COULD POSE A GUSTY WIND  
THREAT.  
 
SOME OF THE MEDIUM RANGE MODELS HINT AT A MID LEVEL DISTURBANCE IN  
THE H5 FLOW AROUND THE PERIPHERY OF THE RIDGE AND INTO OUR AREA  
AROUND THE SATURDAY INTO SUNDAY TIMEFRAME. SURFACE TROUGHING SEEMS  
TO SET UP BECAUSE OF THIS AND THE AFOREMENTIONED TROUGH COULD SERVE  
AS A FOCUS FOR RAINFALL. CONFIDENCE IS NOT HIGH WHEN THIS WILL OCCUR  
BECAUSE OF THE DIFFERENCES IN TIMING AS SOLUTIONS VARY BETWEEN THIS  
OCCURRING ANYWHERE BETWEEN SATURDAY AND SUNDAY. REGARDLESS, WE WILL  
RETURN TO NORTHERLY FLOW THEREAFTER AS THE MODELS AGREE THAT THE  
RIDGE'S POSITION WILL STAY THE SAME. /JMZ/  
 
AVIATION...  
 
18Z TAF PACKAGE...CONVECTION IS THE GREATEST IMPACT  
THROUGH THE AFTERNOON AND EARLY EVENING. SOME LOW CIGS ARE  
IMPACTING TERMINALS OFF AND ON LEADING TO TEMPO MVFR CIGS BUT  
OVERALL AS LONG AS THESE SITES REMAIN CONVECTION FREE THEY SHOULD  
REMAIN IN VFR STATUS. AFTER CONVECTION WINDS DOWN ALL TERMINALS  
WILL MOVE BACK INTO VFR STATUS IF NOT ALREADY THERE BUT AROUND  
9/10Z WE COULD SEE THE SAME ISSUES WE HAVE BEEN FOR THE LAST FEW  
DAYS WITH IFR AND POSSIBLY LIFR CIGS ALONG WITH PATCHY IFR VSBYS.  
THE MOST LIKELY TIME TO SEE THESE IMPACTS WILL BE FROM 9-13Z AND  
PROBABLY OVER THE SAME LOCATIONS LIKE MCB AND BTR. /CAB/  
 
MARINE...  
 
PERSISTENT ONSHORE FLOW WILL CONTINUE INTO TOMORROW. BY  
TOMORROW AND WEDNESDAY NIGHT, A WEAK LOW PRESSURE SYSTEM IN THE  
CENTRAL GULF COULD PUSH WINDS AND SEAS HIGHER. THIS LOW WILL TRACK  
INTO TEXAS BY FRIDAY, AND WINDS ARE EXPECTED TO DROP BACK TO 10  
KNOTS OR LESS. ADDITIONALLY, WINDS AND SEAS WILL BE HIGHER NEAR  
ANY THUNDERSTORM ACTIVITY THAT DEVELOPS TODAY AND THAT ALSO  
INCLUDES THE POSSIBILITY OF WATERSPOUTS.  
 
TIDES WILL BE A PROBLEM THROUGH OUT THE WEEK. THE SOUTHEASTERLY  
WINDS WILL BE IN PLACE ACROSS MUCH OF THE GULF AND THIS WILL OCCUR  
IN COMBINATION WITH THE SPRING TIDE. THIS WILL CAUSE SOME TIDAL  
ISSUES IN THE KNOWN TROUBLE SPOTS AND A COASTAL FLOOD ADVISORY  
REMAINS IN EFFECT THROUGH MIDDAY THURSDAY.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
MCB 70 86 70 86 / 30 90 30 90  
BTR 73 89 73 87 / 50 90 20 90  
ASD 74 88 73 87 / 10 90 40 90  
MSY 76 87 76 87 / 10 90 30 90  
GPT 75 87 74 87 / 20 90 50 90  
PQL 74 87 73 87 / 20 90 50 90  
 

 
   
LIX WATCHES/WARNINGS/ADVISORIES
 
 
LA...COASTAL FLOOD ADVISORY UNTIL 1 PM CDT THURSDAY FOR LAZ066>070-  
076-078.  
 
GM...NONE.  
MS...COASTAL FLOOD ADVISORY UNTIL 1 PM CDT THURSDAY FOR MSZ080>082.  
 
GM...NONE.  

 
 

 
 
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