Colorado Mesoscale Discussion

Areas affected…Central/Northern NM…Southern CO

Concerning…Heavy rainfall…Flash flooding likely

Valid 031805Z – 032305Z

SUMMARY…Convective initiation expected soon across
central/northern NM and southern CO for what should be an active
day for monsoonal showers and thunderstorms. Some flash flooding
will be possible this afternoon.

DISCUSSION…The latest GOES-16 Geocolor satellite imagery is
showing a build-up of CU and TCU over the higher terrain of the
Sangre De Cristo mountains from northern NM and into southern CO,
and also farther back to the west along portions of the San Juan
mountains. This will lead to more widespread convective initiation
going through the afternoon hours with monsoonal showers and
thunderstorms becoming more numerous.

The latest RAP analysis does show a rather notable pool of
instability across areas of far northeast NM, southeast CO and the
OK/TX Panhandles involving the High Plains where boundary layer
heating and elevated surface dewpoints are focusing as much as
1000 to 2000 j/kg of MLCAPE. The low-level flow is generally out
of the east-northeast across these areas and extending west to the
eastern slopes of the higher terrain and especially the Sangre De
Cristo range. This more favorable thermodynamic environment in
conjunction with orographics and terrain-induced circulations will
favor slow-moving and locally anchored showers and thunderstorms
over the terrain by mid-afternoon, with cells then advancing
gradually off the terrain as storm scale cold pools evolve.
Steering currents aloft though will be rather weak given the
position of the deep layer ridge over the Four Corners region.

PWATs across the MPD threat area are gradually rising and are
expected to reach 1.5 to 2 standard deviations above normal by
late-afternoon. Moisture was relatively concentrated in the
300/500 mb layer of the 12Z KABQ RAOB sounding, with a tad more
dry air noted below this down to the surface. However, the
persistent low-level easterly fetch across eastern NM should
transport more moisture westward from the High Plains and will
facilitate additional moistening of the column through the
afternoon.

The latest hires model guidance favors as much as 2 to 3 inches of
rain, with locally higher amounts going through the late-afternoon
hours. Some flash flooding will be possible as a result, and this
will especially be the case in and around any burn scar locations.

Orrison

…Please see www.wpc.ncep.noaa.gov for graphic product…

ATTN…WFO…ABQ…EPZ…GJT…PUB…

ATTN…RFC…ABRFC…CBRFC…WGRFC…

LAT…LON 38430569 38400538 38170507 37840475 36820426
35850444 35080500 34010519 33010516 32510532
32530578 32830599 33490613 33860653 34350663
34950660 35460687 35850719 36230756 37130743
37680778 38020760 38220717 38160670 37710635
37280622 37010592 37120566 37410557 37870568
38190584

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