WPC Met Watch |
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Mesoscale Precipitation Discussion: #0466 (2018) |
(Issued at 323 AM EDT MON JUL 16 2018
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MPD Selection |
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MESOSCALE PRECIPITATION DISCUSSION 0466
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
323 AM EDT MON JUL 16 2018
AREAS AFFECTED...CENTRAL KANSAS
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 160723Z - 161145Z
SUMMARY...THUNDERSTORMS SHOULD CONTINUE TO TRAIN OVER PORTIONS OF
CENTRAL KANSAS IN THE EARLY MORNING HOURS. RAIN RATES TO AROUND 2
IN/HR WILL BE POSSIBLE WITH THE POTENTIAL FOR FLASH FLOODING WHERE
STORMS ARE MOST PERSISTENT.
DISCUSSION...A NW-SE ORIENTED BAND OF CONVECTION HAD DEVELOPED
OVER CENTRAL KANSAS BETWEEN 05-07Z IN THE INTERSTATE-70
CORRIDOR...AND WAS BEGINNING TO BACKBUILD TO THE NORTHWEST NEAR
HAYS. THE MEAN FLOW VECTORS IN THIS REGION ARE VERY WEAK (10 KNOTS
OR LESS) AND GENERALLY ALIGNED PARALLEL TO THE CURRENT CONVECTIVE
BAND...AS ARE THE BACKBUILDING STORM MOTION VECTORS. THIS SHOULD
FAVOR CONTINUED TRAINING AND LONGER RESIDENCE TIMES OF HEAVY RAIN
IN INDIVIDUAL LOCATIONS... PARTICULARLY CENTERED ON RUSSELL AND
ELLSWORTH COUNTIES. 60+ MINUTE RADAR LOOPS FROM KICT SHOW HARDLY
ANY EFFECTIVE STORM MOTION...THE CONVECTION APPEARED TO BE SITTING
STILL...AND THIS WILL LIKELY LEAD TO A LOCALIZED SWATH OF HEAVY
RAINFALL. LOCAL TOTALS IN EXCESS OF 4 INCHES WILL BE
POSSIBLE...AND KICT RADAR DUAL POL ESTIMATES ALREADY SHOW RAIN
RATES AROUND 2 IN/HR IN THE STRONGEST CONVECTION. THIS MESOSCALE
SETUP AND RADAR TRENDS SHOULD THEREFORE SUPPORT A RISK OF FLASH
FLOODING IN CENTRAL KANSAS EARLY THIS MORNING.
PRECIPITABLE WATER VALUES BETWEEN 1.5 AND 2.0 INCHES AND
TALL...NARROW CAPE PROFILES WILL FAVOR HIGHER RAINFALL EFFICIENCY
AND THE HEAVY RAIN RATES ALREADY CITED. THE MAIN LIMITING FACTOR
APPEARS TO BE TIME FRAME AND HOW LONG LOW-LEVEL CONVERGENCE WILL
BE ABLE TO SUSTAIN THE CONVECTION. RIGHT NOW THE THUNDERSTORMS
WERE DEVELOPING IN A ZONE OF ENHANCED CONVERGENCE...BUT THIS MAY
BEGIN TO WEAKEN IN A FEW HOURS. UNTIL THEN...SLOW-MOVING AND
NEARLY STATIONARY CONVECTION APPEARS LIKELY TO CONTINUE.
LAMERS
ATTN...WFO...DDC...GID...GLD...ICT...TOP...
ATTN...RFC...ABRFC...MBRFC...
LAT...LON 39469973 39239829 38759705 38059721 38119823
38689977 39210025
Last Updated: 323 AM EDT MON JUL 16 2018
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