Mesoscale Precipitation Discussion 0621
NWS Weather Prediction Center College Park MD
343 PM EDT Thu Aug 09 2018

Areas affected...Northern New Mexico, Southern Colorado

Concerning...Heavy rainfall...Flash flooding possible

Valid 091942Z - 100115Z

Summary...Thunderstorms will continue to develop along higher
terrain in southern Colorado and northern New Mexico this
afternoon. These storms may move slowly and eventually drift into
lower elevation areas as well. The slow storm motion may allow for
an inch or more of rainfall in an hour or less at some locations,
which could lead to flash flooding.

Discussion...GOES-16 and GOES-15 satellite imagery indicated
numerous thunderstorms initiating along higher terrain in southern
Colorado and northern New Mexico early this afternoon. The GOES-16
Convection RGB highlighted many thunderstorms of moderate
strength, with a few localized stronger updrafts with smaller ice
particles. The convective development is expected to continue into
the afternoon, with some mergers or consolidation possible given
the amount of vigorous convection in the region. An upper level
low was also centered near the NM-CO border, with a weakness in
the flow. Mean winds (850-300mb) across the outlined area were
generally around or less than 5 knots, and the strength and
pattern of the upper level flow should create some nearly
stationary thunderstorms, with a tendency to sit near areas of
higher terrain. The slow storm motions will favor rapid
accumulation of rainfall, with 1.0 to 1.5 in/hr rain rates
possible. Although the instability and moisture levels are not
particularly high for this time of year, they are sufficient to
produce 1 in/hr rain rates, and given the slow storm motions,
localized maxima of several inches of rain appear possible. This
could lead to flash flooding, particularly in smaller, narrow
basins or near burn scars.

Lamers

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

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

LAT...LON   38870584 38040465 36440361 34920457 34420591
            35390624 35960697 36940728 37560801 38300728