733
AWUS01 KWNH 270932
FFGMPD
MOZ000-ARZ000-OKZ000-KSZ000-271430-
MESOSCALE PRECIPITATION DISCUSSION 0538
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
531 AM EDT SAT JUN 27 2026
AREAS AFFECTED...NORTHEAST OK, FAR SOUTHEAST KS, SOUTHWEST MO,
NORTHWEST AR
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 270930Z - 271430Z
SUMMARY...SHOWERS AND THUNDERSTORMS WITH 1-2"/HR RAIN RATES WILL
CONTINUE FOR A FEW MORE HOURS THIS MORNING. BRIEF TRAINING OF
THESE RATES COULD PRODUCE 2-3" OF RAIN WITH LOCALLY HIGHER
AMOUNTS, LEADING TO INSTANCES OF FLASH FLOODING, ESPECIALLY ATOP
VULNERABLE SOILS.
DISCUSSION...THE REGIONAL RADAR MOSAIC EARLY THIS MORNING
INDICATES CONTINUED DEVELOPMENT OF SHOWERS AND THUNDERSTORMS
ACROSS NORTH-CENTRAL OK AND FAR SOUTHERN KS. THIS ACTIVITY IS
BLOSSOMING IN RESPONSE TO SEVERAL FORCING MECHANISMS, INCLUDING A
SHORTWAVE EXITING THE TX PANHANDLE, A SLOWLY VEERING 45 KT LLJ
CONVERGING ACROSS CENTRAL OK, AND AN EMBEDDED MCV NOTED IN
REFLECTIVITY. THE RESULTANT ASCENT IS OCCURRING WITHIN ROBUST
THERMODYNAMICS CHARACTERIZED BY PWS MEASURED BY GPS OF 1.9 - 2.1
INCHES, OVER THE 90TH PERCENTILE FOR THE DATE, OVERLAPPING MUCAPE
OF 2000-300 J/KG. THIS HAS PRODUCED RECENT HOURLY RAINFALL
MEASURED VIA MRMS OF 1-1.5", LEADING TO A FEW SCATTERED FFWS FROM
THE LOCAL WFOS OVERNIGHT.
THE RECENT HIGH-RES GUIDANCE IS NOT EXCITED ABOUT REDEVELOPING
CONVECTION THE NEXT SEVERAL HOURS, SO CONFIDENCE IS MODEST AS TO
HOW THIS CONVECTION WILL EVOLVE. HOWEVER, EVEN AS THE LLJ VEERS
DIURNALLY THROUGH THE MORNING, IT SHOULD STILL MAINTAIN STRONG
THERMODYNAMIC ADVECTION NORTHEASTWARD, AND WILL LIKELY CONTINUE TO
EXCEED THE MEAN 850-300MB WINDS FOR SEVERAL MORE HOURS. THIS
SUGGESTS FURTHER CONVECTIVE DEVELOPMENT, WITH THE SHORTWAVE AND
MCV PROVIDING LOCALLY BACKED AND ACCELERATED FLOW TO ADDITIONALLY
SUPPORT THUNDERSTORM DEVELOPMENT. WITH THE ENVIRONMENT EXPECTED TO
REMAIN QUITE FAVORABLE FOR HEAVY RAINFALL RATES, ADDITIONAL
THUNDERSTORMS WILL LIKELY (>60% CHANCE FROM BOTH THE REFS AND
HREF) CONTAIN RAINFALL RATES OF 1-2"/HR. WHILE CELLS SHOULD BE
PROGRESSIVE TO THE ENE AROUND 20 KTS, REPEATING ROUNDS OF
CONVECTION ARE EXPECTED, LEADING TO RAINFALL THAT HAS A 30-40%
CHANCE OF EXCEEDING 3".
MOST CONCERNING FOR THE CONTINUING FLASH FLOOD RISK IS THAT ANY
HEAVY RAINFALL ASSOCIATED WITH THIS CONVECTION WILL BE OCCURRING
ATOP VERY VULNERABLE SOILS. 7-DAY RAINFALL HAS BEEN 300-600% OF
NORMAL, EVEN EXCLUDING OVERNIGHT RAIN, PRODUCING 0-40CM SOIL
MOISTURE THAT IS ALMOST UNIFORMLY ABOVE THE 95TH PERCENTILE. THIS
HAS CREATED COMPROMISED FFG THAT IS AROUND 2"/3HRS, BUT IS LOCALLY
AS LOW AS JUST 0.25"/3HRS. THIS INDICATES THAT EVEN AS STORMS MOVE
PROGRESSIVELY EASTWARD AND BEGIN TO WEAKEN AS THE LLJ VEERS, ANY
HEAVY RAIN COULD RESULT IN ADDITIONAL INSTANCES OF FLASH FLOODING
DUE TO THE SENSITIVITY OF THE SOILS ACROSS THE REGION.
WEISS
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...ICT...LSX...LZK...OUN...PAH...SGF...TSA...
ATTN...RFC...KRF...MSR...ORN...TUA...NWC...
LAT...LON 37939254 37849165 37299114 36969108 36529123
36039191 35449390 35169517 35059604 35439711
36089787 36589802 36939775 37059679 37069617
37069583 37309494 37529394 37769347
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