554  
AWUS01 KWNH 300358  
FFGMPD  
MSZ000-LAZ000-300800-  
 
MESOSCALE PRECIPITATION DISCUSSION 0054  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1056 PM EST SUN JAN 29 2023  
 
AREAS AFFECTED...SOUTH-CENTRAL/SOUTHEAST LA...SOUTHERN MS  
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE  
 
VALID 300355Z - 300800Z  
 
SUMMARY...ADDITIONAL BANDS OF SHOWERS AND THUNDERSTORMS MAY  
CONTINUE TO FOSTER SOME FLASH FLOODING CONCERNS GOING THROUGH  
MIDNIGHT.  
 
DISCUSSION...THE LATEST RADAR IMAGERY CONTINUES TO SHOW MULTIPLE  
BANDS OF HEAVY SHOWERS AND THUNDERSTORMS ADVANCING ACROSS AREAS OF  
SOUTH-CENTRAL/SOUTHEAST LA AND INTO SOUTHERN MS. THE ACTIVITY IS  
BEING DRIVEN BY THE APPROACH OF A WELL-DEFINED SHORTWAVE CROSSING  
THE LOWER MS VALLEY WHICH IS INTERACTING WITH A VERY MOIST  
SOUTHWEST LOW-LEVEL JET OF 30 TO 40+ KTS CROSSING THE CENTRAL GULF  
COAST AND OVERRUNNING A QUASI-STATIONARY FRONT DRAPED ACROSS THE  
REGION.  
 
OVERALL, THE NOSE OF INSTABILITY IS RATHER MODEST, BUT THE  
LOW-LEVEL JET IS FAVORING AN AXIS OF MUCAPE VALUES OF 500 TO 1000  
J/KG ALONG AND JUST NORTH OF THE WEST/EAST FRONTAL ZONE JUST NORTH  
OF THE GULF COAST. FORCING ASSOCIATED WITH THE WARM ADVECTION  
PATTERN AND SHORTWAVE DYNAMICS ALOFT WILL CONTINUE TO INTERACT  
WITH THE THE AVAILABLE THERMODYNAMICS TO YIELD AT LEAST BROKEN  
COVERAGE OF SHOWERS AND THUNDERSTORMS GOING THROUGH 06Z (12AM CST).  
 
THE CONVECTION IS GENERALLY ALIGNED WITH THE DEEPER LAYER STEERING  
FLOW OUT OF THE WEST-SOUTHWEST, AND THIS IS YIELDING SUFFICIENT  
LEVELS OF CELL-TRAINING FOR THERE TO BE CONTINUE TO BE AT LEAST  
SOME EXCESSIVE RAINFALL CONCERNS. SOME STREET FLOODING HAS BEEN  
REPORTED RECENTLY IN PORTION OF LINCOLN COUNTY, MS WHERE CELLS  
HAVE BEEN REPEATING OVER THE SAME AREA OVER THE LAST COUPLE OF  
HOURS.  
 
PWS ARE NEAR 1.5 INCHES, AND WITH THE AFOREMENTIONED INSTABILITY  
AND FORCING STILL TRAVERSING THE CENTRAL GULF COAST REGION, THE  
RAINFALL RATES SHOULD STILL REMAIN RATHER HIGH AND CAPABLE OF  
REACHING 1 TO 2 INCHES/HOUR.  
 
THE 00Z HREF GUIDANCE SUGGESTS THERE COULD STILL BE A WINDOW FOR  
AN ADDITIONAL 2 TO 3 INCHES OF RAIN LOCALLY, AND SOME OF THESE  
ADDITIONAL RAINS MAY OVERLAP WITH AREAS THAT WERE HIT WITH HEAVIER  
RAIN EARLIER IN THE DAY. CONSEQUENTLY, THERE SHOULD BE AT LEAST A  
LOCALIZED THREAT OF ADDITIONAL FLASH FLOODING OVER THE NEXT FEW  
HOURS GOING THROUGH MIDNIGHT.  
 
ORRISON  
   
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...JAN...LCH...LIX...MOB...  
 
ATTN...RFC...LMRFC...NWC...  
 
LAT...LON 32128961 32048869 31528852 31058885 30548991  
30289066 30129185 30419232 30869207 31519075  
 
 
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