MESOSCALE PRECIPITATION DISCUSSION 0511
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
320 PM EDT SUN JUL 22 2018

AREAS AFFECTED...CA SIERRAS...MTN RANGES OF CENTRAL AND EASTERN
NV...

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

VALID 221920Z - 230100Z

SUMMARY...NEAR RECORD DEEP MOISTURE AND SLOW CELL MOTIONS ACROSS
STEEP SLOPES POSE FLASH FLOODING RISK THIS AFTERNOON INTO EVENING.

DISCUSSION...12Z SOUNDINGS FROM REV AND LNK ARE RUNNING NEAR THE
MAX MOVING AVERAGE WELL ABOVE 95TH PERCENTILE OF MOISTURE WITH TPW
OF 1.04" AND 0.95" RESPECTFULLY.EVEN TDS IN THE MID-50S ARE
OBSERVED IN THE EASTERN SLOPES OF THE SIERRAS FROM BIH TO BLU/RNO.
 WHILE THE MEAN SHORTWAVE IS ROTATING AWAY ACROSS UT/WY THE
ANTICYCLONIC UPPER LEVEL FLOW STILL FEEDS THE RIGHT ENTRANCE TO A
40-50KT 250MB JET THAT FROM MONO/INYO COUNTY TOWARD NORTHERN UT. 
THIS IS PROVIDING MODERATE BROAD SCALE ASCENT AND INCREASED LOW
LEVEL CONVERGENCE FOR THE MOUNTAIN CONVERGENCE CIRCULATION.  CIRA
LAYERED PW LOOP SHOW THIS JET CIRCULATION WELL TOO WITH MID-LEVEL
MOISTURE POOLING IN THE COL BETWEEN THE UPPER LOW OFF SHORE AND
THE EASTWARD MOVING SHORTWAVE...MAXIMIZING THIS MOISTURE FOR THIS
ASCENT.  AS SUCH MID-LEVEL CLOUD BEARING FLOW IS LIMITED SO CELLS
WILL BE VERY SLOW MOVING AND GIVEN THE AMPLE MOISTURE...RATES OF
1" TO 1.5"/HR ARE LIKELY AND TOTALS OF 1-2" ARE PROBABLE WITH
ISOLATED SPOTS GREATER THAN 3" POSSIBLE POSING FLASH FLOODING, MUD
AND DEBRIS FLOWS ESPECIALLY INSIDE AND DOWNSTREAM FROM BURN SCARS.


GALLINA

ATTN...WFO...HNX...LKN...REV...STO...VEF...

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

LAT...LON   40691481 40211419 38721432 38001585 37691734
            36961792 36381819 36481856 36711875 37811971
            39282091 40332169 40602089 39181945 39621773
            40591617