879
AWUS01 KWNH 152032
FFGMPD
MOZ000-ARZ000-160100-
MESOSCALE PRECIPITATION DISCUSSION 1089
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
431 PM EDT MON SEP 15 2025
AREAS AFFECTED...NORTH TO SOUTH CENTRAL MISSOURI...FAR
NORTH-CENTRAL ARKANSAS...
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 152030Z - 160100Z
SUMMARY...BAND OF SLOW MOVING PULSE-LIKE CONVECTION WITH
1.5-1.75"/HR AND WIDELY SCATTERED LOCALIZED TOTALS TO 2"+ IN 1-3
HOURS. LOCALIZED FLASH FLOODING AND LOW-WATER CROSSING ISSUES ARE
POSSIBLE THROUGH EVENING.
DISCUSSION...A NARROW RIBBON OF ENHANCED MOISTURE AND LOW-LEVEL
THETA-E IS BEING SQUEEZED BY OBLIQUE PASSING OF VERY BROAD/STRONG
UPPER-LEVEL TROUGH OVER MUCH OF THE NORTHWEST CONUS AND RETURN
FLOW UNDER THE CLOSED RIDGE OVER THE GREAT LAKES. THIS RIBBON OF
1.5-1.75" EXTENDS ALONG THE UPPER MISSISSIPPI RIVER THROUGH MO
INTO CENTRAL ARKANSAS. SOLID SURFACE HEATING WITH TEMPERATURES
INTO THE LOW 90S OVER MID 60S TDS SUPPORTED FAIRLY UNSTABLE
ENVIRONMENT WITH 2000-2500 J/KG OF MLCAPE ALONG THE EASTERN/UPWIND
EDGE OF THE DEEPER MOISTURE PLUME.
THE DEEPER LAYER CONFLUENCE, ALONG WITH WEAKENED CAP RESULTED IN
INITIAL THUNDERSTORMS, THOUGH RECENT UPTICK HAS BEEN NOTED OVER A
MUCH LONGER LENGTH OF THE INSTABILITY/MOISTURE AXIS. STRONG
UPDRAFTS WITH NUMEROUS OVERSHOOTING TOPS DOTTING THE LENGTH OF THE
CONVECTIVE LINE, FROM SHELBY TO OSAGE TO TEXAS AND TO HOWELL
COUNTY IN MO, BECOMING MORE SCATTERED FURTHER SOUTH WHERE
MID-LEVEL CONVERGENCE IS SLIGHTLY REDUCED (NOSE OF RETURN FLOW
ACROSS SOUTH-CENTRAL MO).
VERY OBLIQUE RIGHT ENTRANCE DIVERGENCE AND SUBTLE 20KT EFFECTIVE
BULK SHEAR MAY ALLOW FOR SOME VERTICAL DISCONNECT TO THE
UP/DOWNDRAFT COUPLETS TO SUPPORT A FEW UPDRAFT CYCLES, THOUGH
OVERALL ORGANIZATION IS FAIRLY WEAK AND CELL LONGEVITY IS LIKELY
TO BE LIMITED TO 1-2 HOURS. HOWEVER, VERTICAL LOADING TO THE
DOWNDRAFT AND VERY SLOW CELL MOTIONS MAY ALLOW FOR RATES OF
1.5-1.75"/HR AND MAY RESULT IN WIDELY SCATTERED 2"+ TOTALS IN LESS
THAN 2HRS. OVERALL, THE GROUNDS ARE QUITE DRY WITH 0-40CM
RELATIVE SOIL MOISTURE AT OR BELOW 30%, SO WHILE FFG VALUES ARE
VERY HIGH, THEY MAY BE DISCOUNTING THE INITIAL HARDER/IMPERMEABLE
NATURE BEFORE EVENTUAL INFILTRATION OCCURS, AND GIVEN THE SHEER
RATE, THE INITIAL RUNOFF MAY BE HIGHER THAN EXPECTED, RESULTING IN
WIDELY SCATTERED FLASH FLOODING CONDITIONS, ESPECIALLY NEAR
LOW-WATER CROSSINGS THAT DOT THE AREA AND THEREFORE IS CONSIDERED
POSSIBLE OVER THE NEXT 3-4 HOURS.
GALLINA
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...EAX...LSX...LZK...SGF...
ATTN...RFC...KRF...MSR...ORN...NWC...
LAT...LON 40379249 39809183 39149162 37979136 37299133
36429134 36109214 36389272 36909316 38189353
39829328 40369283
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