25/118 PM.
Hotter than normal conditions will continue for the foreseeable future, generally hottest through Sunday. Slight cooling is expected Monday through Wednesday, with heat increasing again Thursday into the weekend. The hot daytime and warm night conditions will bring elevated risks of heat-related illness. Gusty NW winds will affect SW Santa Barbara County at times, with gusty onshore winds over the interior.
(Sat-Tue), 25/818 PM.
Overall, latest models in good synoptic agreement through the short term period. At upper levels, high pressure centered near the 4 Corners will slowly wobble eastward through the period. At the surface, moderate onshore flow will continue to the east with weak to moderate northwesterly flow at times.
Forecast-wise, main issue in the short term will continue to be the heat. Highs today topped out in the mid 90s to 104 across the valleys and interior sections. Given the synoptic pattern, will expect H5 heights and thicknesses to slowly decrease through Tuesday. So, Sunday will likely be the warmest day with a bit of cooling for most areas Monday and Tuesday. With warm overnight low temperatures, conditions will remain rather uncomfortable. Heat Risk grids indicate moderate to high heat risk will continue through Monday. So, current suite of HEAT ADVISORIES, as well as the EXTREME HEAT WARNING for the Antelope Valley, are looking good through Monday evening.
Secondary concern for the short term will be winds, specifically Sundowner winds across southern Santa Barbara county. Based on high resolution data, northerly offshore pressure gradients peak Sunday evening and again Monday evening (SBA-SMX gradients forecast to be -3.7 mb). So, there will be some gusty northerly winds across the Santa Ynez Range, especially the western half, and Wind Advisories may be needed, beginning tomorrow.
Tertiary concern, and a minor one at that, will be some influx of mid-level moisture on Sunday. At this time, the convective threat does not look too scary. However, there will be a 5-10% chance of thunderstorms over the LA and Ventura county mountains Sunday afternoon. If any thunderstorms do form, there will be the threat of dry lightning.
Given the hot temperatures, as well as low surface humidity and gusty winds, there will be elevated to potentially brief critical fire weather conditions across interior sections through the period. Any grass fires will likely spread very quickly. Additionally, mixing heights will be quite high. So, there will be the potential for some significant, plume-dominated, fire behavior if any fires ignite.
(Wed-Sat), 25/117 PM.
The large area of high pressure will continue to impact the region through the long term. The center of the high pressure will move slightly east Tuesday through Wednesday, bringing some relief from the heat, but only by a few degrees. Coastal areas will see the most noticeable drop in temperatures as onshore gradients strengthen, allowing low clouds and fog to expand some. Additionally, PWATs will finally drop below 1 inch by Tuesday afternoon, meaning it will be/feel less humid than it has been these past few weeks.
The majority of the ensemble solutions show the ridge of high pressure pushing back to the west around Friday or Saturday of next week. This will likely push temperatures back up a few degrees, but the warming may be mainly focused over the mountains and interior valleys as the onshore flow changes little. Thankfully, PWATs are not forecast to increase drastically like they have over the last week or two of warm ups the region has had, which means the air will feel drier than it has.
26/0117z.
At 0005Z at KLAX, the marine layer was 900 ft deep. The top of the inversion was near 2600 ft with a temperature of 29 Celsius.
High confidence in VFR conditions through Sunday at KPRB, KSBP, KSBA, KBUR, KVNY, KPMD AND KWJF. Low confidence in coastal TAFs. If low clouds do form, LIFR to IFR expected on the Central Coast, with IFR conds for the Ventura and LA Coast. There is a 30-40 percent chance of any coastal site (except KSBA which has VFR forecast) remaining clear, or that CIGs will be patchy or short lived. Timing could be off by +/- 2 hours. Gusty onshore winds will continue to affect KPMD and KWJF.
KLAX, For the 00Z TAF, High confidence in VFR conds through 06Z, followed by low confidence through 16Z-18Z. IFR to MVFR conds forecast from 08Z-17Z but timing could be off by +/- 2 hours. In addition, there is a 30% chance of no restrictions, or that CIGs form intermittently, or for a short period of time. High confidence in any east wind component staying under 6 knots.
KBUR, High confidence in the 00Z TAF with VFR conds through Sunday afternoon with typical winds.
25/846 PM.
For the outer waters, moderate to high confidence in the current forecast. Small Craft Advisory (SCA) level winds can be expected most of the time through Thursday night. Local gale force gusts will be possible tonight, with periods of gales possible through the week. SCA level steep and choppy seas are also expected due to the consistent, moderate to strong winds.
For the inner waters north of Point Sal, generally high confidence in the current forecast. SCA level wind gusts should be prevalent much of the time through Wednesday evening followed by conds dropping below SCA levels for Thursday and Thursday night. Steep choppy seas are expected much of the time as well.
For the southern inner waters, moderate to high confidence in the current forecast. The western Santa Barbara Channel will likely see SCA level wind gusts at times mainly in the afternoon and evening hours through Tuesday night. Otherwise and elsewhere, conds will remain below SCA levels through Thursday night.
25/847 PM.
A long period (20-22 seconds) southern hemisphere swell will add to the continuing swell from Hurricane Fausto. This swell will result in an increased risk of dangerous rip currents across the coastal beaches, as well as elevated surf of 3-6 ft across the Los Angeles and Ventura County Beaches. In addition there are strong longshore currents, and powerful breaking waves due to the very long periods. Dangerous conditions have been reported from area beaches, with the highest hazard on exposed south to southwest facing beaches.
A Beach Hazard Statement is in effect at least through the weekend for Los Angeles and Ventura County beaches and the Central Coast beaches.
The Eastern Pacific will remain active with Hurricane Genevieve forecast to track from a location SW of mainland Mexico NWWD to a point well west of southern Baja over the next 5 days. This will result in additional southerly swells to impact the coastline through the middle of next week. As a result, the Beach Hazards Statement has been extended through Wednesday for south and southwest facing beaches.
Ca, Heat Advisory remains in effect until 8 PM PDT Monday for zones 38-88-342>345-348>358-362-366>382-548. (See LAXNPWLOX). Beach Hazards Statement in effect through Wednesday afternoon for zones 340-346-354-362-366. (See LAXCFWLOX). Extreme Heat Warning in effect until 8 PM PDT Monday for zone 383. (See LAXNPWLOX). PZ, Small Craft Advisory in effect until 3 AM PDT Tuesday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 6 PM PDT Sunday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect until 5 PM PDT Monday for zones 670-673-676. (See LAXMWWLOX).
