MESOSCALE PRECIPITATION DISCUSSION 0183...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1054 PM EDT WED JUL 09 2014
CORRECTED FOR TYPOS IN THE SECOND PARAGRAPH
AREAS AFFECTED...CENTRAL NE INTO CENTRAL KS
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 100245Z - 100845Z
SUMMARY...SCATTERED THUNDERSTORMS WITH HEAVY RAIN CORES COULD
TRAIN ACROSS PORTIONS OF CENTRAL NE AND CENTRAL KS OVER THE NEXT
SEVERAL HOURS AS CELLS BACKBUILD ACROSS NE. A FEW INSTANCES OF
FLASH FLOODING COULD OCCUR.
DISCUSSION...A COLD POOL HAS BECOME ESTABLISHED ACROSS CENTRAL AND
EASTERN NE IN ASSOCIATION WITH SCATTERED CONVECTION ACROSS THE
REGION, LEAVING AN OUTFLOW BOUNDARY ACROSS PORTIONS OF CENTRAL NE
AND NORTH-CENTRAL KS. EARLIER, A TRAINING BAND SET UP PRODUCING
2-4" OF RAIN IN A SHORT TIME ACROSS NORTHEAST NE. INFLOW AT 850
HPA IS INCREASING, CURRENTLY IN THE 30-40 KT RANGE, WHICH HAS BEEN
LEADING TO CELL BACKBUILDING ACROSS NE OVER THE PAST FEW HOURS.
PRECIPITABLE WATER VALUES ARE 1.50-1.75", AROUND THE 90TH
PERCENTILE FOR MID JULY. UPSTREAM CAPES ARE IN THE 1000-2000 J/KG
RANGE. THIS ENVIRONMENT MEETS THE THRESHOLD OF THE WET MULTI-CELL
ENVIRONMENT.
AS 850 HPA INFLOW INCREASES SLIGHTLY FURTHER, REMAINING MORE THAN
DOUBLE THE 850-400 HPA MEAN WIND, PRECIPITATION EFFICIENCY SHOULD
REMAIN HIGH, IF NOT INCREASE SLIGHTLY, ACROSS THE REGION.
CONVECTION SHOULD REMAIN ELEVATED OVER THE OUTFLOW BOUNDARY DUE TO
THE PRESENCE OF SOME CIN IN THE REGION, PER THE 12Z ARW, AS IT
CONTINUES DROPPING SOUTHWARD THROUGH KS. THE MEAN 700 HPA 12C
ISOTHERM SHOULD PRECLUDE WESTERN NE AND WESTERN KS FROM MORE THAN
AN ISOLATED FLASH FLOOD THREAT, BUT WOULD ALSO MAINTAIN THE HIGH
CAPE RESERVOIR AS THUNDERSTORM ACTIVITY SHOULD NOT EXHAUST THE
SUPPLY OVERNIGHT. AS 850 HPA WINDS VEER DUE TO THE MOVEMENT OF A
SHORTWAVE TROUGH THE REGION, THE ACTIVITY SHOULD EXTEND INTO
CENTRAL KS BY 09Z. THE LATEST NSSL WRF, SPC WRF, HRRR, AND
PARALLEL NAM CONEST APPEAR TO BE CAPTURING THE EXPECTED
PRECIPITATION PATTERN THE BEST (USING ARW AND RAP MASS FIELDS AS A
GUIDE). RAINFALL RATES UP TO 2.5" AN HOUR ARE EXPECTED, WHICH
COULD DROP A QUICK 2-4" LOCALLY DUE TO CELL TRAINING AS ADVERTISED
WITHIN THE MESOSCALE QPF GUIDANCE. A FEW INSTANCES OF FLASH
FLOODING COULD OCCUR.
ROTH
ATTN...WFO...TOP...ICT...GID...LBF...DDC...GLD...
ATTN...RFC...ABRFC...MBRFC...
LAT...LON 38089848 38769974 40720088 41700058 41829896 40389792
38779745 38089848
Last Updated: 1054 PM EDT WED JUL 09 2014