Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
910 am PDT Sat Oct 10 2015
a heat advisory is in effect through 8 PM today for the coastal
and valley areas where it will be nearly as hot as it was yesterday.
Highs will range from 95 to 105. Mountains and deserts will very
warm too. A slow cooling trend will take place Sunday through
Wednesday. A low pressure system will move inland across California
next week and bring with it a slight chance of showers and
thunderstorms Wednesday and Thursday.
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
A heat advisory was issued this morning for the coastal and valley
areas today. The warm start to the day will lead to another
very hot afternoon. Morning lows were in the middle to upper 70s at
many locations west of the mountains.
Broken record department: the low of 77 at Lindbergh Field shattered
the old record (70) for the highest minimum temperature for this
date. The low of 77 is also the all-time highest minimum on record
for the month of October. The old record was 73 set on October 15th,
1961. Another indicator of just how unusually warm it was this
morning is that the average high at Lindbergh Field today is 73.
Coastal temperatures are higher than valley temperatures
this morning...primarily due to the easterly winds and downslope
warming that made it all the way to the beaches last night. The
winds were strongest near Camp Pendleton and Red Beach where
temperatures hovered around 80 most of the night. At 9 am the
temperature at both Red Beach and Carlsbad was 90. The Hot Spot was
Miramar which was already a blistering 94 degrees.
The easterly winds will abate by midday and a weak sea breeze will
spread across the coastal zones and into the valleys in the
*** From previous discussion ***
South flow develops over the coastal waters on Sunday and this
should bring a greater marine influence and greater coastal cooling
on Sunday. Cooling will then spread gradually inland through the
middle to latter part of next week with high temperatures still a
little above average for the latter part of next week.
The low pressure system that brought precipitation to Southern
California last Sunday and Monday continues to make a slow clockwise
loop with it moving from central Baja California today to farther off the
central Baja California coast by late Monday. It then moves toward the north
and then northeast...moving inland across central and Southern
California late Wednesday and Thursday...weakening and moving east
The circulation around this low pressure system will draw somewhat
higher precipitable water values into Southern California Monday
through Wednesday with the GFS generating some quantitative precipitation forecast over the
mountains and deserts Tuesday and Wednesday afternoons. For late
Wednesday into Thursday and Friday...far Southern California is in
relatively drier southwest flow aloft with higher precipitable water
values to the south and also closer to the center of the low
pressure as it moves into the central California coast. The European model (ecmwf)
remains drier in model quantitative precipitation forecast for Thursday versus the GFS...but MOS
numbers are not all that different for the two models. The forecast
has a slight chance of afternoon and early evening thunderstorms...
mainly for the mountains and deserts on Thursday followed by drying
into next weekend.
101515z...mostly clear with unrestricted visibilities through
Sunday. Local east winds gusting to 25 knots across mountain
ridges and below passes and Canyon West side of the mountains
will create moderate-strong uddfs and low level wind shear over and
west of the mountains through about 19z today. Some patchy
stratus and fog is possible after about 11/12z late tonight
over the coastal waters based around 400 feet mean sea level with tops
around 900 feet mean sea level. The confidence in the ksan taf forecast
of mainly clear conditions tonight through Sunday morning
is moderate to high. The risk of broken low clouds at ksan
Sunday morning is very low.
800 am...no hazardous marine weather is expected through Wednesday.
800 am...long-period southwest swells will continue for
strong rip currents...as well as elevated surf of 3 to 6 feet with
occasional sets to 7-8 feet at southwest facing beaches through
Monday. Today an additional 3-4 foot/14 second west swell will
help bring a boost in surf and rip current activity to
west-facing beaches. Southwesterly and west swell will gradually
diminish Sunday and Monday. By Tuesday into Wednesday a building
4-5 foot/13-15 second northwest swell could bring elevated
surf and strong rip currents to exposed west-facing beaches.
For more details...see the surf forecast...laxsrfsgx
..and the beach hazards statement...Laxcfwsgx.
Skywarn activation will not be needed today.
California...heat advisory until 8 PM PDT this evening for Orange County
coastal areas-Orange County inland areas-San Bernardino and
Riverside County valleys-the inland Empire-San Diego County
coastal areas-San Diego County valleys-Santa Ana Mountains
Beach hazards statement through Sunday evening for Orange County
coastal areas-San Diego County coastal areas.