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
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page