Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
940 PM PDT Tuesday Jul 22 2014
warmer through the end of the week as high pressure builds aloft
over The Four Corners region. The hottest days will be Thursday and
Friday when high temperatures will be 5 to 10 degrees above average.
A shallow marine layer will moderate temperatures near the coast.
Increasing monsoonal moisture over the weekend will bring increasing
humidities and also increase the chances for showers and
thunderstorms over the mountains Sunday.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
The trough off the coast will lift north this week and the heat will
build heat through Friday as the 599dm upper high over Colorado
builds toward the 4-corners region. The hottest days will be
Thursday and Friday when heights peak near 595dm over so-cal. Maximum
temperatures in the lowers deserts will peak near 115...and highs in the
inland Empire will top out between 100-105. Synoptic scale
subsidence will squash the marine layer below 1000 feet by weeks
end. Low cloud coverage will not be very widespread and limited to
the coastal zones the next few days. There will still be some
semblance of a shallow marine layer though...which will moderate
temperatures near the coast.
The 00z sounding showed dry southwest flow above 10000 feet and a
precipitable water of only 0.82". The winds aloft gradually shift
south Friday under the influence of the 4-corners high...and then
southeast over the weekend for a greater influx of middle and high
level moisture. Most of the moisture is elevated so the chance for
convection Saturday are too small to mention. Chances increase
Sunday when an easterly wave treks across Southern California
bringing greater instability.
Outlook for early next week...the upper level high settles over the
southwest and will continue to bring above average temperatures.
Prevailing southeasterly monsoon flow will bring small chances of
mountain convection with any shortwaves.
230330z...coast/valleys...sct/bkn low clouds with bases near 1000 feet
mean sea level and tops 1500 feet mean sea level will develop over the coastal waters by
early Wednesday morning. These clouds will push slowly inland after
23/0900z and affect portions of the beaches and coastal mesas.
Impacts for the coastal airports will be a brief low ceiling if the
clouds push far enough inland. Confidence is low to moderate on how
widespread and organized the cloud deck will be. Expect these low
clouds to erode back to the coast between 23/1300z-1600z. Low clouds
with similar bases and tops will push inland after 24/0500z Tuesday
Mountains/deserts...few clouds around 15000 feet and unrestricted
visibility through Wednesday night.
at 8 PM PDT...the San Clemente buoy was reported winds sustained 19
knots gusting to 23 knots. Gusty northwest winds will continue over the outer
coastal waters through early Thursday morning. Expect sustained
winds 15 to 20 knots...with gusts to 25 knots...which may be hazardous to
small craft. A Small Craft Advisory is in effect through 5 am
California...heat advisory from 11 am Thursday to 9 PM PDT Friday for the
Coachella Valley...Riverside County mountains...San Bernardino
County mountains...San Bernardino and Riverside County
valleys-the inland Empire...San Diego County deserts...San
Diego County mountains.
Pz...Small Craft Advisory for winds through 5 am PDT Thursday
for the waters from San Mateo Point to the Mexican border
extending 30 to 60 nm out including San Clemente Island.