MESOSCALE PRECIPITATION DISCUSSION 0207
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1204 PM EDT THU MAY 11 2017

AREAS AFFECTED...PORTIONS OF THE KS/OK BORDER

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

VALID 111603Z - 112203Z

SUMMARY...CONVECTION HAS BEGUN TO FORM ALONG THE WESTERN KS/OK
BORDER AS CIN ERODES ACROSS THE REGION.  HOURLY RAIN RATES UP TO
1.5", WITH LOCAL AMOUNTS OF 2-4", COULD LEAD TO ISSUES OVER
PARTIALLY SATURATED SOILS.

DISCUSSION...AN INVERTED TROUGH FROM A WAVE OF LOW PRESSURE IN
NORTH CENTRAL OK HAS CAUSED A THUNDERSTORM TO FORM ALONG THE
WESTERN OK/KS BORDER -- AN INITIAL SIGN THAT CIN IS ERODING ACROSS
THE REGION.  PRECIPITABLE WATER VALUES ARE 1-1.4" PER GPS
INFORMATION FROM 12-13Z, CONFIRMED BY 12Z UPPER AIR FLIGHTS IN THE
AREA.  INFLOW AT 850 HPA IS 25-40 KTS FROM THE WARM SECTOR, WHERE
MLCAPES ARE 1000-2000 J/KG.  BULK SHEAR IN THE 0-6 KM LAYER IS
30-50 KTS PER RECENT SPC MESOANALYSES.

THE EXPECTATIONS ARE FOR MORE THUNDERSTORM ACTIVITY TO FORM AND
EXPAND EASTWARD NEAR THE KS/OK BORDER AS CIN FURTHER ERODES. 
THUNDERSTORMS WITH HEAVY RAIN ARE EXPECTED TO TRACK INITIALLY
EAST-NORTHEAST AT 25 KTS BEFORE TURNING MORE EASTWARD WITH TIME. 
WITH WEAKENING 850-400 HPA WINDS ACROSS THE AREA, THUNDERSTORMS
ARE EXPECTED TO BE QUITE EFFICIENT AT PRODUCING HEAVY RAIN WITH
SLOWER MOVING PULSE ACTIVITY BEING FORCED TO MERGE INTO QUICKER
MOVING MORE ORGANIZED CELLS.  CELL TRAINING SHOULD BECOME AN
INCREASING CONCERN WITH TIME.  RECENT SATELLITE IMAGERY INDICATES
THAT THE BOUNDARY ACROSS NORTHEAST OK SHOULD SHIFT UP TOWARDS THE
KS BORDER IN THE THERMAL FIELD OVER THE NEXT HOUR OR TWO WHERE
DIFFERENTIAL HEATING SHOULD TAKE OVER BETWEEN CLOUDY AND
INCREASINGLY PARTLY CLOUDY REGIONS, WHICH SHOULD BE THE PRIMARY
FOCUS.  THE MESOSCALE GUIDANCE SHOWS RELATIVELY GOOD AGREEMENT ON
THE SCENARIO AND RAINFALL PATTERN EXPECTED.  HOURLY RAIN RATES UP
TO 1.5", WITH LOCAL AMOUNTS OF 2-4", COULD LEAD TO FLASH FLOODING.

ROTH

ATTN...WFO...DDC...ICT...OUN...SGF...TSA...

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

LAT...LON   37979694 37629444 36409402 35969683 36739934
            37219995 37649964