357
AWUS01 KWNH 031831
FFGMPD
NMZ000-AZZ000-040000-

Mesoscale Precipitation Discussion 0546
NWS Weather Prediction Center College Park MD
231 PM EDT Wed Jul 03 2024

Areas affected...Southeastern AZ...Southwest & Western NM...

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

Valid 031830Z - 040000Z

SUMMARY...Slow moving monsoon thunderstorms capable of .75-1"/hr
rates and spots of 1-1.5" may pose possible widely scattered
incidents of flash flooding.

DISCUSSION...Overall meteorological conditions continue to
downtrend relative to prior days; however, lingering above average
low level moisture, full insolation and favorable mid to upper
level orientation within the gap between two ridges and modest
outflow channel to the northeast across NM should spur widely
scattered thunderstorms in the next few hours.   GOES-E satellite
suite shows an old MCV across northwest Chihuahua with downstream
deformation zone providing solid cloud cover diminishing
insolation there.  To the west, peripheral enhanced moisture still
resides in SE AZ in the upper 50s to low 60s Tds and total PWats
near 1.25" especially along/the southern most counties of SE AZ/SW
NM.  RAP analysis shows a trough of cooler temps at 5H across NE
to east-central AZ, aiding cooling aloft and steepening lapse
rates.  This is also supporting northwesterly flow aiding
convergence with southerly/southwesterly flow across SE AZ toward
the Black Mountain range.  As such, instability is increasing with
pockets of up to 2000 J/kg of SBCAPE along the northwest edge of
the mid-level cloud cover.  Upslope mountain flow is starting to
result in increased convective development on the peaks;
eventually this will expand off peak and reach deeper moisture
inflow to support .75-1"/hr rates toward peak heating in 2-3
hours.

Steering flow is weak in the larger scale mid-level trough, but
with limited organization; pulse convection is likely the main
mode and should result in some spots of 1-1.5" through 00z; but in
a widely scattered to scattered nature.  Given the grounds are
saturated (where it isn`t barren rock), run-off should be above
average, especially over SE AZ where precipitation anomalies are
400-600% of normal and soil conditions are in the upper 5th
percentiles.  Though with more conditional organization to cells,
slightly reduced moisture (and localized flux) than prior days,
flash flooding is considered possible in that widely scatter-shot
distribution along and northwest in the MPD area of concern.

Gallina

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

ATTN...WFO...ABQ...EPZ...FGZ...TWC...

ATTN...RFC...CBRFC...WGRFC...NWC...

LAT...LON   34390764 33640728 32750763 31420823 31260950
            31251094 31521171 31971165 32541108 32941067
            33450997 34000967 34070878