570
AWUS01 KWNH 100655
FFGMPD
AZZ000-100854-

Mesoscale Precipitation Discussion 1176
NWS Weather Prediction Center College Park MD
254 AM EDT Fri Oct 10 2025

Areas affected...southern/central Arizona

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

Valid 100654Z - 100854Z

Summary...Isolated flash flood potential continues as convection
drifts north-northeastward across the discussion area.  Rain rates
of around 0.5 inch/hr are possible at times through 11Z/3a PDT.

Discussion...Scattered shower/isolated thunderstorm activity has
been persistent for most of the evening, although steady
north-northeastward movement has tended to keep rain rates in
check (generally under 0.5 inch/hr).  Recent radar/satellite
indicate a subtle uptick in convection generally from the Phoenix
area southward to the International Border region that may be tied
to a weak mid-level wave approaching the area.  Subtle confluence
at both 700mb and 850mb may also be contributing to the modest
increase in convective activity.  Lightning data has also shown an
uptick in vicinity of the storms.  Deep layer flow in excess of 20
knots will continue to support northward movement of cells,
although if strengthening continues, areas of localized training
could bump rain rates into the 0.5 inch/hr range.  PW values
exceeding 1.5 inch and marginal instability (around 500 J/kg
MUCAPE) are supportive of heavier rainfall with the more dominant
activity.

As typical for the region, low-lying areas and burn scars that
experience heavier rainfall could result in an instance or two of
flash flooding for the next few hours.  The longer-term
persistence of this activity is in question, however, as
convergence/confluence may weaken some later tonight (after 10Z).
As such, a conditional threat for flash flooding could continue
around southern/central Arizona for the next few hours while cells
persist.

Cook

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

ATTN...WFO...FGZ...PSR...TWC...

ATTN...RFC...STR...NWC...

LAT...LON   35201135 34631040 32081113 31821276 32391397
            34051318