28/128 PM.
Night through morning low clouds will prevail through most of this week, with temperatures well below normal through at least Thursday. Modest warming likely to follow. Drizzle is possible especially near the foothills. Gusty winds will continue over the interior mountains and deserts, as well as southwest Santa Barbara County through at least early next week.
(tdy-Thu), 28/209 PM.
The upper trough situated over the Great Basin is expected to lift northeast into Monday. In tandem, a shortwave trough will dive due south along the British Columbia coast deepening some into Socal. The upper pattern will slow down with weak troughing continuing across the west into Thursday.
Moderate to strong onshore flow is expected to persist to the east through Thursday. Expected to weaken somewhat thereafter but likely to remain moderately onshore. Onshore flow to the north (LAX-BFL) is expected to increase some through Wednesday (peaking near 6mb). 500 mb heights are expected to decrease to near 577 dm Monday night. Then, will gradually rise through the remainder of the short-term (but remaining below average).
This will result in below average temperatures continuing through the period, coolest across the interior (8 to 15 F below normal). Night through morning low clouds will prevail through the week reaching into the interior valleys (Santa Clarita), and even in areas that usually do not see low clouds. Drizzle will be possible especially across the foothills due to the enhancement of orographic lifting. PWATs will be the highest across the LA Basin on Tuesday given the aforementioned synoptic setup. Would not be surprised to see even a few light showers across the foothills of San Gabriel Mountains.
Sundowners are expected again tonight. However, SBA-SMX gradient according to the ECWMF projections will likely fall into the negative 2 to 3 mb range. Likely to be insufficient for an wind advisory (30% chc) but localized wind gusts to 45 mph such as at Refugio is possible. Expecting the gustier winds to have a shorter duration. Evening NW winds across SW SB county will continue Monday into Tuesday (Sub-advisory). Better chance for advisory Wed & Thurs, but marginal if it materializes. Gusty winds will continue across the far interior thru the period. Any advisory level winds that develop will likely remain localized through Tuesday.
(Fri-Sun), 28/209 PM.
Good consensus among ensemble and deterministic guidance of high pressure building over the region Friday and Saturday. This will result in a warming trend into July 4th weekend as 500mb heights continue to rise and gradients trend offshore. Temperatures will likely warm even more into next week - however, there is quite the range in solutions. Stay tuned for updates.
28/1759z.
At 17Z at KLAX, the marine layer was 3800 ft deep. The top of the weak inversion was 10,000 feet with a temperature of 12 Celsius.
High confidence continues for VFR TAFs for KPMD KWJF with abnormally strong and persistent onshore winds. KPRB will likely stay clear with only a 20% chance of seeing clouds today or Monday.
Moderate confidence in ceilings at all other airports today. Moderate confidence in timing (+/- 3 hours) and flight categories (+/- 1 category. The rest should see ceilings, but coverage and timing will be difficult to predict as the inversion continues to weaken. Expect the marine layer to push back in tonight with most places seeing with the exception of KPMD and KWJF MVFR. Low to moderate chance some locations drop down to IFR.
KLAX, High confidence for ceilings today continue, moderate confidence Monday. Moderate confidence in timing (+/- 3 hours) and flight categories (+/- 1 category). 50% chance of southeast winds 8-10 knots 13-17Z tonight.
KBUR, High confidence in ceilings today, moderate confidence Monday. Moderate confidence in timing (+/- 3 hours) and flight categories (+/- 1 category). Southeast winds likely longer lasting than normal.
28/136 PM.
High confidence in Small Craft Advisory (SCA) level winds continuing for the outer waters from the Central Coast through San Nicolas Island through Monday morning, with some improvement still expected after. The nearshore Central Coast waters should continue to see SCA winds today focused this afternoon and evening, with chances decreasing Monday and Tuesday.
Moderate confidence in SCA winds over the western Santa Barbara Channel late this afternoon and evening once again, with lowering chances to follow. The rest of the waters will likely stay under SCA.
All waters will see short-period choppy seas into early next week.
Ca, NONE. PZ, Small Craft Advisory in effect until 3 AM PDT Monday for zones 645-650. (See LAXMWWLOX). Small Craft Advisory in effect until 9 AM PDT Monday for zones 670-673-676. (See LAXMWWLOX).
