Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service San Diego California
550 PM PDT Monday Jul 28 2014
drier air moving into the region will limit thunderstorm chances to
the mountains on Tuesday and Wednesday...then diminish chances for
the remainder of the week. Near normal temperatures will continue
through mid-week...then increase to slightly above normal through
the weekend. High pressure aloft will continue a shallow marine
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Thunderstorm activity had diminished over the area by 6 PM PDT.
The possibility of isolated to scattered showers and thunderstorms
will continue this afternoon...mainly over the far inland
valleys...mountains and deserts. Although there is plenty of
monsoonal moisture across the area...widespread storm activity is
not expected at this time from subsidence trailing behind the
disturbance aloft. Storms that do develop could generate heavy
rain...localized flash flooding...gusty winds and cloud-to-ground
The aforementioned upper-level high pressure will shift south
Tuesday...shifting the upper-level flow from southeast to SW. This will
help transport some middle and upper-level moisture to the area from
Tropical Storm Hernan. Clouds and virga are expected from the SW
flow. However...isolated thunderstorms will be possible Tuesday
and Wednesday afternoon...mainly over mountain peaks.
The high will then build west over SW California Thursday through the
end of the week...which will help to dry out the
atmosphere...remove the possibility of thunderstorms and slightly
increase high temperatures to a few degrees above normal through
Friday. 28/1200 UTC European model (ecmwf)/GFS/Gem model runs hint at precipitation
returning to the mountains and deserts possibly by the end of next
weekend. Since they have been inconsistent for the past few runs
and disagree on timing...have left storms out of the forecast for
now. The marine layer will remain fairly shallow and patchy...with
low clouds and fog restricted mainly to the coast and coastal
282000z...coasts/valleys...a patchy low cloud deck with bases
near 1000 feet mean sea level and tops 1300 feet mean sea level should develop over the
coastal waters tonight and move up to 5 sm inland between 28
/0900z-1300z... affecting ksan...kcrq...and ksna. Confidence of a
broken/overcast layer occurring at these airports is low to moderate. Sky clear
conds expected during the day Tuesday.
Mountains/deserts...multiple scattered-broken cloud layers at or above 8000
feet mean sea level.
115 PM PDT...no hazardous marine weather expected tonight through
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.