464
AWUS01 KWNH 100834
FFGMPD
ALZ000-MSZ000-LAZ000-101330-
MESOSCALE PRECIPITATION DISCUSSION 0013...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
334 AM EST SAT JAN 10 2026
CORRECTED FOR CONCERNING LINE: FLASH FLOODING LIKELY
AREAS AFFECTED...EASTERN LOUISIANA...SOUTHERN MISSISSIPPI
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY
VALID 100830Z - 101330Z
SUMMARY...PRE-FRONTAL CONFLUENCE BAND ACTIVATING WITHIN NARROW
REMAINING INSTABILITY AXIS IN PROXIMITY TO MOISTURE AXIS ENOUGH TO
SUPPORT 1.75-2"/HR RATES. CELL MOTIONS SUPPORT SOME SHORT-TERM
REPEATING THOUGH ALREADY SATURATED/FLOODED AREAS. AS SUCH,
LOCALIZED FLASH FLOODING IS LIKELY TO OCCUR AGAIN THROUGH EARLY
MORNING.
DISCUSSION...GOES-E 10.3UM AND REGIONAL RADAR DEPICT AN AREA OF
INCREASING CONVECTIVE DEVELOPMENT ALONG A LOW LEVEL CONFLUENCE
LINE EXTENDING FROM NEAR MARSH ISLAND ACROSS BATON ROUGE, LA
TOWARD MCCOMB MS BEFORE INTERSECTING WITH A BROADER WEST TO EAST
RAINFALL REINFORCED OUTFLOW OR EFFECTIVE ISENTROPIC BOUNDARY. RAP
ANALYSIS DEPICTS A NARROW INSTABILITY AXIS WITH 1500-1750 J/KG OF
MLCAPE AND GENERALLY ALIGNS WITH THE WESTERN EDGE OF SLIGHTLY
HIGHER LOW LEVEL MOISTURE WHERE TDS CLIMB ABOVE 70 A FEW DEGREES.
VWP ALSO NOTE AN INCREASE IN LOW LEVEL WIND SPEEDS TOWARD 40+KTS
AND REMAIN FAIRLY UNIDIRECTIONAL THROUGH 500MB WELL AHEAD OF THE
FRONTAL ZONE. AS SUCH, THERE REMAINS A FAVORABLE TRAINING
ORIENTATION FOR THE CONVECTION. SPC MCD 18 ALLUDES TO FAVORABLE
SHEAR ENVIRONMENT FOR SOME ROTATING CELLS AS WELL, FURTHER
INCREASINGLY MOISTURE FLUX CONVERGENCE ALLOWING FOR RATES TO REACH
1.75-2"/HR POTENTIALLY. UPSTREAM COLD FRONT IS STARTING TO PRESS
EASTWARD, BUT THERE REMAINS A FEW HOURS OF POTENTIAL TRAINING OF
THESE CELLS. THIS MATCHES MOST CLOSELY TO THE 00Z ARW SOLUTION AS
WELL AS RECENT RAP RUNS THOUGH OTHER RAPID REFRESH GUIDANCE
PROVIDES SOME INCREASED CONFIDENCE TO THIS EVOLUTION.
UNFORTUNATELY, THE ORIENTATION APPEARS TO INTERSECT LOCATIONS THAT
HAD RECEIVED OVER 4" YESTERDAY AFTERNOON. THIS HAS RESULTED IN
COMPROMISED FFG VALUES BELOW 2"/HR FOR SOLID PORTION OF THE MPD
AREA OF CONCERN AND WITH 1-2 HOURS OF TRAINING SPOTS OF ADDITIONAL
2-3" ARE PROBABLE AND WOULD LIKELY RESULT IN LOCALIZED FLASH
FLOODING TO OCCUR ONCE AGAIN ACROSS FAR NORTHERN EAST LOUISIANA
INTO SOUTHERN MS. COMBINE THIS WITH ANY REMAINING CONVECTIVE
CELLS ALONG THE COLD FRONT PASSING THROUGH BY 14-15Z, CONSIDER THE
POTENTIAL FOR FLASH FLOODING TO ONCE AGAIN BE LIKELY ACROSS THIS
AREA INTO THE EARLY MORNING HOURS.
GALLINA
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...BMX...JAN...LIX...MOB...
ATTN...RFC...ALR...ORN...NWC...
LAT...LON 33058867 32998809 32558766 31878777 31448828
31178870 30878924 30549032 30359117 30689162
31319135 31909091 32838963
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