MESOSCALE PRECIPITATION DISCUSSION 0592
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
321 PM EDT WED OCT 21 2015
 
AREAS AFFECTED...MUCH OF NM/NORTH TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 211920Z - 212320Z
 
SUMMARY...SCATTERED CONVECTION TRACKING OVER AREAS WITH LOW FLASH
FLOOD GUIDANCE COULD RESULT IN FLASH FLOODING THROUGH THE LATE
AFTERNOON.

DISCUSSION...CONVECTION IS INCREASING IN COVERAGE ACROSS MUCH OF
NM AND FAR NORTH TX IN RESPONSE TO DIFFLUENCE AHEAD OF A CLOSED
MID LEVEL LOW OVER AZ. ACROSS CENTRAL NM...CONVECTION IS FORMING
WHERE CIN HAS BEEN ERASED AND MLCAPE VALUES HAVE JUMPED TO BETWEEN
1000-1500 J/KG. MOISTURE VALUES HERE ARE RELATIVELY LOW...WITH
PRECIPITABLE WATER VALUES NEAR 0.80 INCHES. 850-400 MB WINDS HAVE
BACKED WITH THE APPROACH OF THE MID LEVEL SYSTEM...AND HAVE BECOME
BETTER ALIGNED WITH THE CORFIDI VECTORS... SUGGESTING
TRAINING/BACKBUILDING COULD BE THE MAIN FLASH FLOOD THREATS. THREE
HOUR FLASH FLOOD GUIDANCE VALUES ARE AS LOW AS 1.00 TO 1.50
INCHES...ESPECIALLY OVER HIGHER TERRAIN AND AREAS THAT SAW
RAINFALL THIS TIME YESTERDAY. THE COMBINATION OF REPEAT CELLS AND
LOWER FLASH FLOOD GUIDANCE VALUES SUGGESTS FLASH FLOODING IS
POSSIBLE.

FURTHER EAST...CONVECTION IS FOLLOWING A SURFACE TROUGH STRETCHING
ACROSS NORTH TX FROM SOUTHEAST NM. THESE STORMS HAVE BEEN SEVERE
WEATHER DOMINATED...WITH DRY AIR IN THE MID LEVELS. LOW LEVEL
INFLOW OF 20-25 KNOTS (AS SEEN ON REGIONAL VWP) IS IN PLACE...AND
THE LOW LEVEL INFLOW IS TRANSPORTING PRECIPITABLE WATER VALUES
BETWEEN 1.00 TO 1.25 INCHES INTO THE REGION. THE CIN HERE IS STILL
IN PLACE...AND MAY HAMPER ADDITIONAL CONVECTION TRYING TO MOVE
NORTH ACROSS FAR WEST TX.

THREE HOUR FLASH FLOOD GUIDANCE VALUES HERE ARE ALSO AS LOW AS
1.00 TO 1.50 INCHES ACROSS PORTIONS OF SOUTHEAST NM AND NORTH TX.
THE CONVECTION SHOULD CONTINUE TO BE ORIENTED SOUTHWEST TO
NORTHEAST PER CORFIDI VECTORS...AND REPEAT CELLS WILL RAISE THE
THREAT FOR FLASH FLOODING.

THE LATEST HIGH RESOLUTION GUIDANCE (INCLUDING THE LATEST HRRR AND
RAP) DOES NOT CONTAIN ANY STRONG SIGNALS FOR FLASH FLOODING...WITH
THE BEST AGREEMENT FOR HEAVY RAIN ACROSS EASTERN NM AND FAR NORTH
TX. BECAUSE OF THE UNCERTAINTY...FLASH FLOODING IS ONLY CONSIDERED
POSSIBLE.

HAYES

ATTN...WFO...ABQ...AMA...EPZ...LUB...MAF...

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

LAT...LON   36450258 36390133 35130125 34360163 33170343 
            32070531 31910612 31920623 32160756 32570817 
            33540842 34750836 35150821 35640801 36030775 
            36100750 35890702 35730658 35730404 
!