Graphic for MPD #0581
 
MESOSCALE PRECIPITATION DISCUSSION 0581
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
836 PM EDT FRI OCT 16 2015
 
AREAS AFFECTED...SOUTHERN AZ 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 170035Z - 170600Z
 
SUMMARY..CONVECTION DEVELOPING IN A HIGH MOISTURE CONTENT
ENVIRONMENT AHEAD OF A POTENT SHORT WAVE OVER THE BAJA PENINSULA
COULD PRODUCE FLASH FLOODING THROUGH THE LATE EVENING HOURS.

DISCUSSION...CONVECTION IS INCREASING ON A LOW LEVEL CONVERGENCE
ZONE (SEEN ON THE LATEST VISIBLE SATELLITE IMAGES) ACROSS A
PORTION OF SOUTH CENTRAL AZ. THE CONVECTION IS DEVELOPING IN AN
AREA OF OF 1000-1500 J/KG MLCAPE (THOUGH THE CONVECTION IS
BATTLING LINGERING CIN NEAR THE CONVERGENCE ZONE). PRECIPITABLE
WATER VALUES HAVE INCREASED IN THE MID LEVEL SOUTHERLY FLOW...WITH
GPS SOUNDINGS VALUES NEAR 1.50 INCHES) 

A POTENT SHORT WAVE OVER THE CENTRAL BAJA PENINSULA APPROACHES
NORTHERN MEXICO DURING THE MID TO LATE EVENING HOURS...PROVIDING
SYNOPTIC SCALE ASCENT FOR PRECIPITATION PRODUCTION. THE LATEST
RAP/HRRR SOLUTIONS SUGGEST INSTABILITY (IN THE FORM OF 1000-1500
J/KG OF MUCAPE) REMAINS IN PLACE THROUGH 17/06Z...SUPPORTIVE OF AT
LEAST SCATTERED CONVECTION ACROSS SOUTHERN AZ.

WHILE THERE IS A SIGNATURE IN THE HIGH RESOLUTION GUIDANCE FOR
HEAVY RAINFALL THROUGH 17/06Z...THERE WAS SOME SPREAD ON THE
PLACEMENT. THE 12Z WRF-ARW/NMMB ARE THE FURTHEST EAST...BETWEEN
110W AND THE AZ/NM BORDER. THE 18Z REGIONAL GEM WAS THE FURTHEST
WEST...ON THE WESTERN EDGE OF THE DEEPER MOISTURE PLUME. AT THIS
POINT...IT APPEARS AS THOUGH THE BEST JUXTAPOSITION OF THE DEEP
MOISTURE/INSTABILITY SHOULD BE SOMEWHERE IN BETWEEN. 

ALL MODELS SHOW THE POTENTIAL FOR 1-2 INCH RAINFALL AMOUNTS. ONE
HOUR FLASH FLOOD VALUES ARE CLOSE TO THESE NUMBERS. GIVEN THE
POTENTIAL FOR HIGH RAINFALL RATES...THERE IS A RISK FOR FLASH
FLOODING THROUGH 17/06Z.

HAYES

ATTN...WFO...PSR...TWC...

ATTN...RFC...CBRFC...

LAT...LON   33161058 32380989 30940994 30921141 32411198 
            


Last Updated: 836 PM EDT FRI OCT 16 2015