Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1143 AM EST Sun Nov 15 2026
Day 3
Valid 12Z Tue Nov 17 2026 - 12Z Wed Nov 18 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE FLORIDA EAST COAST AND THE SOUTHWEST U.S....

West...
An upper-trough and accompanying cold front will progress eastward
from the West Coast into the Interior West on Tuesday. Increasing
moisture along and with the frontal passage will lead to scattered
showers and thunderstorms at lower elevations across the Desert
Southwest given precipitable water values on the order of 1 inch in
the Lower Deserts. The fact that the system being progressive is
one factor against the potential for floooding. Despite that...a
Marginal Risk was introduced mainly in the west facing terrain of
northern Arizona...generally at or below 6500 feet (with
precipitation more likely to fall as snow at elevations above 7000
ft). Present indications are that hourly rainfall rates of 1.25
inches are possible whenever/wherever cells can align or merge or
mesocyclones manage to form. Rainfall this intense could lead to
issues in dry washes/arroyos or burn scars.

Eastern Florida...
Surface high pressure parked over the central Appalachians will
keep persistent eastly low-level flow in place across much of the
eastern Florida peninsula on Tuesday into early Wednesday morning
from the Geogia line to Lake Okeechobee (in broad geographic
terms), Precipitable water values of 1.25-1.5" are forecast, and
the low- level flow should bring instability off the warmer than
average Gulf Stream. Effective bulk shear should be sufficient for
organized convection. Hourly rain amounts as high as 1.75" would
be possible wherever short, training bands manage to materialize.
Maintained the Marginal Risk area introduced on Saturday for
portions of Eastern Florida with few changes needed.

Bann

Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt