MESOSCALE PRECIPITATION DISCUSSION 0223
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
259 AM EDT TUE MAY 29 2018

AREAS AFFECTED...EASTERN CO...NORTHWEST KS...EX SOUTHWEST NEB

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 290700Z - 291200Z

SUMMARY...SLOW MOVING/TRAINING CONVECTION ACROSS SATURATED GROUNDS
LIKELY TO LEAD TO FLASH FLOODING THROUGH 12Z.

DISCUSSION...06Z SFC ANALYSIS DEPICTS SURFACE LOW OVER SE CO WITH
INVERTED TROF EXTENDING NORTH THEN ANGLING ACROSS EXT NW KS TO
JUST SOUTH OF MCK.  AN OUTFLOW BOUNDARY FROM EARLIER CONVECTION
LAYS W-E FROM THE INVERTED TROF INTO NW KS SOUTH OF I-70.  AS
DISCUSSED IN MPD 221 CONVECTION HAS DEVELOPED DUE TO STRONG MST
CONVERGENCE ALONG THE INVERTED TROF WHICH IS GENERALLY COINCIDENT
WITH NARROW (NOT DETECTED BETWEEN KPUX AND KGLD) ELEVATED 7H DRY
SLOT FROM THE CT AIR ON SWLY FLOW...WHILE STRONG LLJ AT 850MB AND
NORTHERN BRANCH OF RETURN COOL CONVEYOR ACROSS NW KS/SW NEB (25KT
850MB VWP AT KGLD) AND 45 TO 50KT SWLY LLJ PER KDDC VWP ARE
PROVIDING VERY STRONG MOISTURE CONVERGENCE AND ADVECTION TO
SUPPORT 2000 J/KG MUCAPES AS WELL TO MAINTAIN THESE THUNDERSTORMS.
 THIS MOISTURE FLUX WITH SFC TDS IN THE MID TO UPPER 50S WILL
SUPPORT RATES UP TO 1.0"/HR...THOUGH SATURATED PROFILES AND SLOW
MOTIONS WILL UPTICK THIS TO GREATER THAN 1.5"/HR. 

SHORTWAVE ROUNDING THE BROADER BASE OF THE LARGE SCALE TROF OVER
SOUTH CENTRAL CO IS LIFTING NORTHWARD TOO PROVIDING DPVA WITH
MODEST DIFFLUENCE FOR EVACUATION OF THE UPDRAFTS.  THIS IS
SUPPORTING A WEDGE SHAPED 10UM IR CLOUD SHIELD INDICATIVE OF
POTENTIAL FOR BACKBUILDING/STATIONARY REDEVELOPMENT.  MEAN CELL
MOTION IS GENERALLY ENE ALONG THE LINE OF CONVERGENCE BUT
500-1000MB THICKNESS SHOWS RAPID DIVERGENCE INTO SW NEB SUGGESTING
PILING/MERGERS POSSIBLE ACROSS SW NEB/NW KS AS THE COMPLEX FURTHER
EXPANDS.  RADAR MOSAIC SUGGESTS SOME DRY AIR ENTERTAINMENT HAS
LEAD TO WEAK OUTFLOW/COLD POOL GENERATION TO PROPAGATE THE COMPLEX
EASTWARD SLOWLY.  THE RADAR ALSO SHOWS ISENTROPIC UPGLIDE OVER THE
W-E BOUNDARY TO DEVELOP SCATTERED BUT INCREASING DEVELOPMENT DOWN
STREAM...FURTHER WETTING THE GROUNDS BEFORE THE MAIN LINE. 

HI-RES CAMS SEEM TO BE HANDLING THE DEVELOPMENT WELL BUT MAY BE
UNDER PLAYING SOME OF THE MST FLUX INTO THE COMPLEX AND TOTALS
APPEAR LESS THAN EXPECTED WOULD EXPECT AN ADDITIONAL 2-4" LIKELY
POSSIBILITY HIGHER IF CELLS/OUTFLOW DO NOT DOMINATE AND CELLS LOCK
TO LARGER SCALE ASCENT THAT APPROACHES FROM THE WEST.  GIVEN THE
THREAT AND POTENTIAL FOR MOVING TOWARD RAWLINS/THOMAS COUNTIES
WHERE HEAVY RAINFALL FELL EARLIER TONIGHT AND COMPROMISED FFG
VALUES BELOW AND 1"/1HR 1.5"/3HR...FLASH FLOODING IS CONSIDERED
LIKELY THROUGH 12Z.

GALLINA

ATTN...WFO...BOU...DDC...GID...GLD...PUB...

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

LAT...LON   40330077 40289999 40019964 39449949 38979989
            38710040 38570088 38310223 38400364 38690403
            39080391 39580296 40090185