Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Diego California
909 PM PST Tuesday Feb 9 2016
clear and unseasonably warm through early next week under a
strong high pressure ridge aloft. The ridge will weaken as low
pressure approaches from the Pacific by the middle of next week.
This system will bring onshore flow...cooling...and our next chance
Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
Satellite imagery showed patchy high clouds over socal this evening.
The winds had dropped off to around 15 to 25 miles per hour...with a few higher
gusts on the windiest coastal slopes and below the San Gorgonio Pass
even though the surface pressure gradient was still a healthy 13 mbs
offshore from Tonopah. The 00z Miramar sounding still showed slight
warming compared to yesterday evening...but the low-level easterly
winds had decreased considerably. At 8 PM PST...temperatures west of
the mts ranged from the 60s to middle 70s. Dewpoints were creeping up
along the coast from the 30s into the 40s locally.
Numerous record maximum temperatures were broken today across the region with
many areas cracking the 90 degree mark. Tomorrow looks similar under
Even though the mega ridge aloft is deflating...500h and thickness
over California will remain anomalously high for middle February. The surface
high over the intermountain west will continue near 1030 mbs through
Thursday morning...before weakening. This will favor at least weak
offshore flow most areas and very low relative humidity. By Friday...a
weak trough will be poised off the coast...ready to advance inland
and weaken during the coming weekend. This should bring a period of
onshore flow and slightly higher humidity before high pressure
rebuilds aloft...and at the surface over the Great Basin for more
warm and dry weather early next week.
After about Tuesday...the ridge moves east and the outlook muddies as a
complex trough develops over the far eastpac and slides into California
around midweek. Medium range guidance has come up with a wide
range of solutions trying to piece together the arrival and intensity
of this system...but most solutions have a trough capable of at
least some light precipitation Wednesday/Thursday time frame. Given that...and
climatology...a slight chance of showers is warranted and has been
introduced at the end of the forecast period until we get a clearer
picture of the potential.
100430z...clear skies and unrestricted visible will prevail through
830 PM...no hazardous marine weather is expected through Sunday.
east to northeast winds of 15 to 20 miles per hour with higher gusts are still
likely through and below the passes and canyons...and along the
coastal mountain slopes and foothills through midday Wednesday. This...
combined with well above average temperatures and very low min relative humidity
values of around ten percent Wednesday afternoon...will continue an
elevated wildfire threat for several hours...but not as high as on
Tuesday when wind was more of a factor. Daytime temperatures will
continue well above average until the weekend when modest cooling is
expected with a brief onshore push. The dry and warm weather will
continue into next week.
Even though fuels have been drying after days of full sun...very low
relative humidity...and gusty winds in many areas...the winds are dropping off...so
the issuance of fire weather products is not expected.
Skywarn activation will not be needed on Wednesday.