MESOSCALE PRECIPITATION DISCUSSION 0474
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
429 PM EDT WED JUL 12 2017

AREAS AFFECTED...CENTRAL AND EASTERN CO

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

VALID 122029Z - 130229Z

SUMMARY...THUNDERSTORMS ARE BEGINNING TO DEVELOP ACROSS CENTRAL
AND EASTERN CO.  WITH INCREASING MOISTURE, INSTABILITY, AND
UPSLOPE FLOW, HOURLY RAIN RATES UP TO 2.5" AND LOCAL AMOUNTS UP TO
4" APPEAR POSSIBLE.

DISCUSSION...A COLD FRONT IS DROPPING THROUGH EASTERN CO.  THE
FLOW ALOFT IS SOUTHWESTERLY AND DIVERGENT AHEAD OF AN ELONGATED
UPPER LOW NEAR THE NV/UT/AZ BORDER JUNCTION.  THUNDERSTORMS ARE
STARTING TO DEVELOP ACROSS CENTRAL AND EASTERN CO NEAR THE
BOUNDARY AND AN INVERTED TROUGH/CO CONVERGENCE ZONE NEAR THE FRONT
RANGE.  PRECIPITABLE WATER VALUES RANGE BETWEEN 0.75-1.5" PER THE
RAP ANALYSIS.  MLCAPE VALUES ARE 250-1000 J/KG PRESENTLY.  INFLOW
AT 700 HPA IS NORTHEAST AT 15 KTS INTO THE REGION, ACTING TO
INCREASE MOISTURE AND INSTABILITY.  EFFECTIVE BULK SHEAR IS NEAR
35 KTS PER SPC MESOANALYSES.

CIN SHOULD CONTINUE TO ERODE WHICH SHOULD FOSTER A SHARP INCREASE
IN CONVECTIVE ACTIVITY OVER THE NEXT COUPLE HOURS.  THERE ARE
HINTS WITHIN THE 12 GFS-BASED GDI THAT THUNDERSTORMS SHOULD BECOME
SCATTERED TO NUMEROUS AROUND 00Z NEAR THE FRONT RANGE OF CENTRAL
AND SOUTHEAST CO.  UPSLOPE FLOW IS FORECAST TO MAGNIFY INTO
SOUTHEAST CO WITH TIME AS THE FRONT DROPS INTO NORTHEAST NM, WHICH
SHOULD CAUSE NEW ACTIVITY TO FORM IN AREAS FARTHER SOUTH. 
ORGANIZED CONVECTION SHOULD MOVE EAST-NORTHEAST AT 15 KTS PER
FORWARD PROPAGATION VECTORS AND PARALLEL TO THE 1000-500 HPA
THICKNESS PATTERN WHICH WOULD DOUBLE CLOUD-BASED INFLOW,
ATTEMPTING TO MOVE INTO AN INSTABILITY POOL EXPECTED NEAR THE
CO/KS BORDER.  WITH THE MEAN 850-400 HPA FLOW NO MORE THAN 10-15
KTS, AND STORM BASED INFLOW EXPECTED TO BE DOUBLE THAT,
PRECIPITATION EFFICIENCY IS EXPECTED.  HOURLY RAIN RATES TO 2.5"
AND LOCAL AMOUNTS TO 4" COULD OCCUR NEAR STATIONARY CELLS, CELL
MERGERS, AND IN AREAS WHERE SHORT PERIODS OF CELL TRAINING OCCUR.

ROTH

ATTN...WFO...ABQ...BOU...GJT...GLD...PUB...

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

LAT...LON   39970526 39960319 39790210 38590211 37370267
            36890408 37040605 38090653 39560602