MESOSCALE PRECIPITATION DISCUSSION 0840
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
459 PM EDT FRI SEP 29 2017

AREAS AFFECTED...FAR NORTHEAST AZ...CENTRAL/WESTERN NM...SOUTHWEST
CO

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

VALID 292055Z - 300055Z

SUMMARY...SCATTERED THUNDERSTORMS WITH INTENSE RAINFALL RATES OF
UP TO 1.5 INCHES/HR WILL BE CAPABLE OF PRODUCING SOME FLASH
FLOODING.

DISCUSSION...THE LATEST NON-OPERATIONAL GOES-16 10.3 MICRON/IR
IMAGERY IS SHOWING SOME ADDITIONAL COOLING AND EXPANSION OF
CONVECTIVE TOPS ACROSS AREAS OF NORTHEAST AZ...CENTRAL AND WESTERN
NM AND SOUTHWEST CO. THERE IS A FAIR DEGREE OF DIURNALLY ENHANCED
INSTABILITY IN PLACE WITH MUCAPE VALUES OF AS MUCH AS 1000 TO 1500
J/KG AND THIS COUPLED WITH AS MUCH AS 30 TO 40 KTS OF EFFECTIVE
BULK SHEAR IS FOSTERING THE DEVELOPMENT AND EXPANSION OF
MULTI-CELL CONVECTION. MUCH OF THE SHEAR IS BEING DRIVEN BY
STRONGER MID LEVEL WESTERLY FLOW SOUTH OF AN UPPER LOW SLOWLY
EXITING NORTHEAST UP ACROSS CENTRAL WY.

THE MOISTURE ENVIRONMENT FARTHER SOUTH IS RATHER UNIMPRESSIVE WITH
PWATS OF GENERALLY 0.5 TO 0.6 ACROSS THE REGION...BUT THE CELLS
HAVE BEEN SHOWING SOME ORGANIZATION GIVEN THE SHEAR AND THERE HAVE
BEEN SOME BACKBUILDING AND SMALL SCALE TRAINING TENDENCIES.

SOME ADDITIONAL DIURNAL HEATING WILL TEND TO FOCUS SOMEWHAT
STRONGER INSTABILITY PROFILES OVER THE NEXT COUPLE OF HOURS ALONG
WITH SOME ADDITIONAL CONVECTIVE CELL DEVELOPMENT. EXPECT RAINFALL
RATES OF AS MUCH AS 1.5 INCHES/HR...WITH SOME CONCERNS FOR
BACKBUILDING AND HIGHLY LOCALIZED TRAINING OF CELLS. THIS WILL
PROMOTE SOME FLASH FLOODING CONCERNS.

ORRISON

ATTN...WFO...ABQ...EPZ...FGZ...GJT...PUB...

ATTN...RFC...ABRFC...CBRFC...WGRFC...

LAT...LON   38000837 38000753 37470678 37010581 36460554
            35660553 34610562 33920581 33500616 33230672
            33190739 33330786 33970845 35150878 35770960
            36331001 36860990 37080923 37600894