Graphic for MPD #0554
MESOSCALE PRECIPITATION DISCUSSION 0554
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
332 PM EDT MON JUL 24 2017

AREAS AFFECTED...SOUTHEASTERN NV...EXT EASTERN CA...NORTHWEST
AZ...SOUTHWEST UT

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

VALID 241930Z - 250000Z

SUMMARY...VERY HIGH MOISTURE AVAILABILITY WITH MID TO UPPER LEVEL
SUPPORT SUPPORTS ORGANIZED AND EFFICIENT RAINFALL PRODUCTION.

DISCUSSION...GOES-16 MESO VISIBLE IMAGERY DENOTES CONVECTION
BREAKING OUT ACROSS HIGHER TERRAIN (MT. COLLINGTON) ACROSS
NV...AND RAP ANALYSIS FIELDS SUGGEST RAPIDLY ERODING CINH ACROSS
SE NV WHERE POOL OF INCREASED INSTABILITY WHERE EARLY MORNING
INSOLATION HAS INCREASED SBCAPES TO 2500 J/KG.  WHILE 12Z VEF
SOUNDING INDICATED INVERTED V WITH LOW LEVEL DRY
LAYER...PERSISTENT LOW LEVEL MST ADVECTION FROM THE EASTERN SIDE
OF THE EASTERLY MOVING WAVE (CURRENTLY NEARING THE S NV TIP FROM
LA PAZ COUNTY AZ) IS PROVIDING SOLID MOISTURE FLUX TO PROVIDE A
BETTER SUB-CLOUD ENVIRONMENT FOR EFFICIENT RAINFALL PRODUCTION.
ADDITIONALLY THOUGH FLOW IS WEAK...85-7H FLOW IS ALSO CONVERGENT
ACROSS SE NV/NW AZ AS FLOW TURNS ANTICYCLONIC TO THE DEEP
SOUTHWESTERLY FLOW FURTHER NORTH IN NV/UT.  ALOFT RIGHT ENTRANCE
TO SPEED MAX ACROSS CENTRAL CA SIERRAS PROVIDES EXCELLENT OUTFLOW
TO MAINTAIN UPDRAFT STRENGTH.   ALL OF THIS CONTRIBUTES TO STRONG
CONVECTION WITH THE CAPABILITY OF INTENSE RAINFALL RATES
APPROXIMATELY SIMILAR TO AVAILABLE IN THE LOCAL COLUMN (VERY NEAR
TPW VALUE).  THESE RATES COULD BE AS GREAT AS 2"-2.25"/HR VERY
NEAR THE MCV ACROSS NW AZ.  GIVEN RECENT WET GROUND CONDITIONS AND
POTENTIAL HYDROPHOBIC SOILS...MUCH WILL BE RUNOFF AND LEAD TO
LOCALIZED FLASH FLOODING CONCERNS.  THIS WILL BE PARTICULARLY TRUE
ACROSS RUGGED TERRAIN OR WITHIN THE SLOT CANYONS OF SW UT.  

GALLINA

ATTN...WFO...FGZ...PSR...SLC...VEF...

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

LAT...LON   38881186 38231123 37381152 36571162 35571176
            34451198 33931314 33741389 34051460 35361598
            36711635 37391591 38061433


Last Updated: 332 PM EDT MON JUL 24 2017