Graphic for MPD #0313
MESOSCALE PRECIPITATION DISCUSSION 0313
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
346 PM EDT SUN JUN 17 2018

AREAS AFFECTED...EASTERN ID...WESTERN WY...EXT NORTHERN UT

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

VALID 171946Z - 180046Z

SUMMARY...STRONG DYNAMIC FORCING WITH POTENTIAL FOR
REPEAT/TRAINING STORMS MAY POSE HIGHLY LOCALIZED FLASH FLOODING
RISK THROUGH THIS EVENING.

DISCUSSION...DEEP CLOSED LOW OVER NW NV IS ANGLING SOUTHEAST AND
WITH MID-LEVEL DEFORMATION EXTENDING NE BUT SHIFTING WEST HAS
BROADENED UPPER LEVEL FLOW FOR INCREASING DIFFLUENCE.  3H JET IS
ALREADY REDUCING IN SPEED OVER THE AREA OF CONCERN WITH
UNDERCUTTING JET THROUGH THE GREAT BASIN ALLOWING FOR STRONG RIGHT
EXIT DYNAMICS TO INCREASE DIVERGENCE AND SPIN UP VORTICITY CENTER
SOUTH OF THE AREA OF DISCUSSION.  THIS WILL PROVIDE VERY STRONG
DYNAMIC ASCENT ALOFT WITH THE DIVERGENCE AND DPVA AND ALLOW FOR
INCREASED EASTERLY LOW LEVEL FLOW TO ADVECT MODEST LOW LEVEL
MOISTURE AND BRING TDS INTO THE UPPER 40S AND LOWER 50S.  EARLY
MORNING/AFTERNOON SOLID INSOLATION HAS ALLOWED FOR INCREASED
SURFACE TEMPS TO SUPPORT INSTABILITY GROWTH TO 1000 J/KG FOR
UPDRAFT VIGOR.  THIS SHOULD SUPPORT RAIN RATES INITIALLY AROUND
.5-.75"/HR RATES TRENDING TOWARD HIGHER EFFICIENCY LATER (UP TO
1"/HR) THIS EVENING  AS LOCAL MID-LEVEL PROFILES MOISTEN WITH
INITIAL DOWNDRAFTS/CELL EVAPORATION.  

CURRENT RADAR TRENDS SHOW BROKEN N-S ORIENTED BAND FROM KRXE
TOWARD KEVW.  GENERALLY UNIDIRECTIONAL CLOUD BEARING FLOW SUPPORTS
A TRAINING PROFILE BUT WITH SOME PROPAGATION VECTORS TOWARD THE
INFLOW EAST...IDEAL TRAINING MAY BE A BIT LIMITED BUT GIVEN
STRENGTH OF UPSTREAM DYNAMICS...REPEAT DEVELOPMENT IS LIKELY. 
HI-RES CAMS SUGGEST MAX TOTALS SCATTERED THROUGH THE AREA OF
CONCERN OF 1.5-2" OVER A 2-3 HOUR TIME PERIOD.  AS SUCH HIGHLY
LOCALIZED FLASH FLOODING IS POSSIBLE GIVEN LOW FFG VALUES IN THE
REGION ESPECIALLY OVER E ID AND NEAR THE TETON/JACKSON RANGES. 

GALLINA

ATTN...WFO...PIH...RIW...SLC...

ATTN...RFC...CBRFC...MBRFC...NWRFC...

LAT...LON   44431098 44371063 44121015 43720984 43210946
            42750906 42480908 42050920 41610959 41071024
            41141144 42051170 42521183 42991196 43321203
            43951208 44221191 44381160


Last Updated: 346 PM EDT SUN JUN 17 2018