19/120 PM.
A cooling trend will continue through mid week as an approaching storm brings a return to onshore flow. Light to moderate rain is expected late Monday into Tuesday, focused over San Luis Obispo County with minimal impacts. Widespread gusty west to northwest winds will follow Wednesday through Friday.
(tdy-Wed), 19/200 PM.
Another quiet day of weather on Monday as a cold upper level low slowly marches south down the West coast. Gradients continue to trend onshore meaning cooling will reach farther inland with increasing chances for some morning marine layer near the coast Monday and Tuesday mornings.
Ensemble members are in reasonably good agreement now with the timing of the approaching cutoff low and the resulting rain amounts. Most the solutions are indicating rain beginning late Monday night along the Central Coast and by Tuesday afternoon in LA County, give or take a few hours. Ensemble mean rain amounts are between a half and one inch for the Central Coast and around a quarter inch or less across LA/Ventura Counties. SLO County (and adjacent coastal waters) will be in a marginally favorable position for thunderstorms Tuesday morning with some models showing 500mb temps dropping to around -25c which is one factor in the higher rain amounts there and the rapid drop off in amounts to the south. Peak rain rates in SLO County expected to be around a half inch per hour.
Most of the rain will taper off by Tuesday late afternoon or evening. However, moist west to northwest flow will continue across SLO and northern Santa Barbara Counties overnight and shift to interior SLO County and the northern mountains from northeast Santa Barbara County east to the Grapevine region. These areas will be susceptible to some light upslope showers through Wednesday morning with snow levels around 5000 feet. Rain/snow amounts would be minimal but there could be a dusting of snow above that level.
By Wednesday afternoon most areas will be experiencing gusty west to northwest winds, generally 20-35 mph, but with some gusts as high as 40-50 mph in parts of interior SLO County, the mountains and Antelope Valley. Will likely be needing wind advisories in many areas.
(Thu-Sun), 19/214 PM.
Thursday and Friday will generally be free of any weather impacts with mostly clear skies and temperatures near to slightly below normal. This may continue through the weekend and into next week, however there are quite a few models indicating at least some very light rain, possibly as early as Saturday night along the Central Coast and Sunday morning in LA County. Most solutions show amounts under a quarter inch, and at least half of those, mainly south of Pt Conception, from nothing to a tenth of an inch.
19/2230z.
At 2200Z at KLAX, the marine layer was 700 feet deep. The top of the inversion was 2300 feet with a temperature of 17 degrees Celsius.
For 00Z TAF package, high confidence in CAVU conditions for KPRB, KSBA, KBUR, KVNY, KPMD and KWJF.
For KSBP, there is a 30% chance of LIFR/VLIFR conditions 09Z-16Z.
For KSMX, KLAX, KSMO, KLGB, KOXR and KCMA, there is a 30-40% chance that CIG/VSBY restrictions do not develop. If they do arrive, timing could be +/- 3 hours of current forecast and flight categories could be off by 1-2 categories.
KLAX, Moderate confidence in 00Z TAF. There is a 30% chance that CIG/VSBY restrictions do not develop. If they do develop, timing of arrival could be +/- 3 hours of current 08Z forecast and flight category could be +/- 1 category from current forecast. No significant easterly wind component is expected.
KBUR, High confidence in 00Z TAF as CAVU condition are expected through the period.
19/1147 AM.
A system will move through the coastal waters Monday afternoon through Wednesday morning bringing a chance of showers to much of the area. Cannot rule out a thunderstorm or two across the northern waters Tuesday morning.
SCA level southerly winds are possible along the cold front. By Wednesday afternoon into the evening hours, SCA level NW winds will develop south of Point Conception. These winds will likely expand to include the majority of waters by Thursday afternoon. SCA winds may persist into the weekend at least for some waters.
Ca, NONE. PZ, NONE.
