Graphic for MPD #0861
MESOSCALE PRECIPITATION DISCUSSION 0861
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
611 PM EDT WED OCT 04 2017

AREAS AFFECTED...OKLAHOMA

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

VALID 042045Z - 050245Z

SUMMARY...CONTINUED UPSTREAM REDEVELOPMENT IN SAME GENERAL
VICINITY AND OVERRUNNING SHOWERS ACROSS NORTHEAST OK WILL CONTINUE
FLASH FLOODING THREAT THROUGH THE EVENING HOURS.

DISCUSSION...20Z SFC MESOANALYSIS UTILIZING OK MESONET DEPICT A
WEAK 1022 WAVE NEAR SWO WITH AN EFFECTIVE WARM FRONT DRAPING
SOUTH-SOUTHEAST SW OF OKM TO S OF JSV TO S OF FSM. A STATIONARY
BOUNDARY EXTENDS WEST N OF JWG TOWARD HHF BOUNDING THE
UNSEASONABLE VERY MOIST GULF AIR MASS ACROSS SOUTHWEST OK.  A
FAIRLY AMPLIFIED SHORTWAVE ACROSS E KS AT THIS TIME SUPPORTS A
STRONGLY CONFLUENT LOW LEVEL FLOW PATTERN ACROSS NORTHWEST TX INTO
SW/S OK.  OUTFLOW AND STRONG MOISTURE CONVERGENCE ALONG AND SOUTH
OF THE BOUNDARIES CONTINUES TO ALLOW FOR ASCENT OF THE 2-2.25"
TOTAL PW AIR.  SOME DIFFERENTIAL HEATING ADVECTED INTO OK SUPPORTS
WEAK T/TD SPREAD WITH NEARLY MOIST LOW TO MID-LEVEL LAPSE RATES
ALLOWING FOR SOME MARGINAL INSTABILITY OF UP TO 750-1000 J/KG. 
THIS SUPPORTS SOME VERTICAL GROWTH FOR CONVECTION ALONG THE
SOUTHERN BOUNDARY CAPABLE OF 2"/HR RAIN RATES GIVEN EFFICIENT WARM
CLOUD PROCESSES...FURTHER DOWNSTREAM INTO NORTHEAST
OK...ISENTROPIC ASCENT PROFILES (WITH SATURATED SUB-CLOUD
ENVIRONMENT) ALLOW FOR MORE GENTLE YET EFFICIENT RAIN RATES OF
.5-1"/HR (REDUCING WITH DISTANCE FROM SOURCE WARM SECTOR).

MID-LEVEL DRY AIR CONTINUES TO ADVECT WSW ACROSS EAST CENTRAL TX
AS THE DEEPER MEAN ANTICYCLONE SHIFTS WEST.  THIS SHOULD DISRUPT
THE MOISTURE CHANNEL FROM CENTRAL NORTH TX SHIFTING IT WESTWARD. 
YET WITH THE EXITING WAVE INTO MO...THE CHANNEL WILL NARROW BUT
HAVE MORE OF A WESTERLY COMPONENT TAPPING THE MOISTURE ACROSS WEST
TX (WHICH IS STILL UNSEASONABLY MOIST). AS SUCH THE FRONTAL
BOUNDARY ASCENT CHANNEL AND CONVECTION WILL CONTINUE TO REGENERATE
UPSTREAM ALLOWING FOR REPEATING BETWEEN THE I-40 TO I-44 AREA
THROUGH THE EVENING...MAINTAINING THE THREAT FOR 1.5-2"/HR RAIN
RATES AND POCKETS OF 3-5" TOTALS THROUGH 03Z.  THIS FALLS IN LINE
WITH RECENT HRRR/HRRR V3 AND EXP. ARW2/NSSL-WRF SOLUTIONS.  FLASH
FLOODING IS CONSIDERED LIKELY DUE TO THE ONGOING RAINFALL OVER
SATURATED AREAS IN CENTRAL AND NORTHEAST OK BUT REMAINS SCATTERED
ACROSS WESTERN/SOUTHWEST OK THIS EVENING.  

GALLINA

ATTN...WFO...OUN...TSA...

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

LAT...LON   36959639 36939538 36799470 35589489 34909667
            34479781 34609923 35239982 35579986 35919940
            36119789 36629690


Last Updated: 611 PM EDT WED OCT 04 2017