Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
200 PM PDT Wednesday Jul 23 2014
dry and warmer through the end of the work week as high pressure
builds over the region. The hottest days will be Thursday and Friday
when high temperatures will be 5 to 10 degrees above seasonal
averages. A shallow marine layer will moderate temperatures near the
immediate coast...with only patchy low clouds at the coast during
the nights and mornings. Increasing monsoonal moisture over the
weekend will bring a slight chance for showers and thunderstorms
over the mountains during the afternoon and evening on Saturday and
Sunday. Drier conditions return for the first half of next week.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Clear this afternoon...except for some middle and high clouds streaming
in from the southeast. Current temperatures are mostly 3 to 7
degrees higher than this time yesterday.
Dry SW flow aloft will continue through Friday as the upper level
high centered over Colorado/nm expands westward into socal. This will
bring warmer conditions...primarily for inland areas. Daytime
temperatures will peak on Thursday at about 5 to 10 degrees above
seasonal averages. Temperatures will be highest in the lower
deserts...with some locations in the Coachella Valley and San Diego
County deserts near 116 degrees. Friday will be about as warm...then
temperatures moderate somewhat for the weekend as southeast flow brings
some sub-tropical moisture into the region. The influx of moisture
will also bring a slight chance of afternoon/evening showers and
thunderstorms over the mountains on Sat and sun. Because most of the
moisture will be above 700 mb...any storms that do form will likely
produce only light rain but could produce locally gusty and erratic
winds along with the occasional lightning strike.
For the first half of next week...numerical models are in better
agreement...reducing the amount of monsoonal moisture and all but
eliminating the chances for convection. This drying trend will allow
inland temperatures to rebound...increasing to about 5 degrees above
The building high pressure aloft will keep the marine layer very
shallow...with only patchy low clouds and fog at the coast during
the nights and mornings.
232000z...coast/valleys...VFR conditions through this evening.
Stratus...with bases around 800 feet mean sea level and tops near 1200
feet mean sea level...will develop along the coast early Thursday
morning. Coverage of low clouds will be patchy...and may develop
around 5-10 sm inland by middle Thursday morning. Visibility will lower
to around 1-3 sm due to fog/mist where stratus nears higher terrain.
Low clouds and low visibility will clear by middle to late Thursday
morning. Forecaster confidence in coastal aerodromes remaining
few/scattered from low clouds tonight is moderate.
Mountains/deserts...few clouds at or above 15000 feet and unrestricted
visibility through Thursday afternoon.
100 PM PDT...northwest winds of 15 to 20 knots...with gusts to 25 knots...will
continue over the outer coastal waters through early Thursday
morning. Strongest winds will be near San Clemente Island...mainly
during the afternoons and evenings. A Small Craft Advisory for winds
remains in effect through 5 am Thursday.
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 until 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.