MESOSCALE PRECIPITATION DISCUSSION 0248
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
937 PM EDT THU MAY 31 2018

AREAS AFFECTED...SOUTHERN MO...NORTHERN AR

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 010140Z - 010640Z

SUMMARY...CONVECTION TRAINING EARLY OVER SOUTHERN MO IS EXPECTED
TO MORPH INTO AN ORGANIZED CONVECTIVE CLUSTER THAT AFFECTS
NORTHERN AR DURING THE EARLY MORNING HOURS. FLASH FLOODING IS
POSSIBLE FROM BOTH SYSTEMS THIS EVENING INTO THE OVERNIGHT.

DISCUSSION...REGION RADARS ACROSS SOUTHERN MO SHOWED CONVECTIVE
DEVELOPING ALONG A LOW LEVEL CONVERGENCE AXIS EXTENDING FROM
CENTRAL KS INTO WESTERN KY. THE GOES-16 CLEAN IR LOOP FEATURED
BURSTS OF COLDER CLOUD TOPS WITH THE CONVECTION...AS IT FEEDS ON
2000-3000 J/KG OF MLCAPE (THE 00Z SGF SOUNDING SHOWED 3000+ J/KG
OF SBCAPE). IN ADDITION...THE GOES-16 IR LOOP SHOWED INDICATIONS
OF BACKBUILDING ACROSS SOUTHERN MO...AS THE 850-300 MB MEAN WIND
REMAINS FROM THE WEST.

THE LOW LEVEL CONVERGENCE AXIS ALSO SITS IN AN AXIS OF 1.75/2.00
INCH PRECIPITABLE WATER AIR (WHICH IS MORE THAN TWO STANDARD
DEVIATIONS ABOVE THE MEAN). IN THIS DEEP MOISTURE...THE KSGF RADAR
HAS SHOWN HOURLY RAINFALL RATES NEAR 2.00 INCHES OVER SOUTH
CENTRAL MO. HOWEVER...THE PRESENCE OF DRY AIR IN THE MID LEVELS OF
THE 00Z SGF SOUNDING SUGGEST THAT THESE VALUES COULD BE HAIL
CONTAMINATED.

THE POTENTIAL FOR TRAINING IN THE DEEP MOISTURE AXIS SHOULD
MAINTAIN A THREAT OF FLASH FLOODING OVER SOUTHERN MO THROUGH AT
LEAST 01/04Z...WHERE THE MOST RECENT HRRR SHOWED LOCAL HOURLY
RAINFALL RATES NEAR 2.00 INCHES OVER SOUTHERN MO. THE FACT THE THE
CONVECTION HAS REMAINED SCATTERED THUS FAR HAS LIMITED THE FLASH
FLOOD THREAT.

THERE IS A MULTI MODEL SIGNAL FOR SHORT WAVE ENERGY CROSSING THE
LOW LEVEL CONVERGENCE TO SPIN UP A CONVECTIVE CLUSTER OVER
SOUTHERN MO AFTER 01/04Z. AS THE CONVECTIVE CLUSTER (OR MCS)
DEVELOPS... THERE WILL BE A WINDOW OF OPPORTUNITY FOR TRAINING ON
THE SOUTHERN FLANK OF THE CLUSTER ACROSS NORTHERN AR. AS THE
CLUSTER BECOMES BETTER ORGANIZED...IT SEEMS AS THOUGH THE CLUSTER
MAY BECOME FORWARD PROPAGATING...LESSENING THE THREAT FOR FLASH
FLOODING.

THE MOST RECENT HRRR HAS CONTINUED THAT MODELS TREND OF PRODUCING
AN AXIS OF 3.00 TO 5.00 INCHES OF RAINFALL OVER NORTHEAST
AR...MAINLY AFTER 01/05Z. GIVEN THE MOISTURE IN PLACE...RAINFALL
AMOUNTS OF 3.00+ INCHES ARE CERTAINLY POSSIBLE. HOWEVER...IT IS
NOT YET CLEAR IT THERE WILL BE SUFFICIENT TRAINING AS THE SYSTEM
EVOLVES TO PRODUCE AS MUCH AS 5.00 INCHES OF RAIN. BECAUSE OF
THIS...FLASH FLOODING IS ONLY CONSIDERED POSSIBLE AT THIS TIME.

HAYES

ATTN...WFO...LSX...LZK...MEG...PAH...SGF...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...

LAT...LON   37409151 37319010 35948969 35059036 34779120
            35299239 36489385 37139317