22/201 PM.
Hotter than normal conditions will continue through at least early next week, especially starting Thursday. The hot daytime and warm night conditions will bring elevated risks for heat illness. Thursday through Sunday will generally be the hottest of the next seven days. Gusty north winds will affect some areas through Friday.
(tdy-Sat), 23/200 AM.
Nothing but heat is in store for Srn CA for the short term (and most of the long term)
A very large and hot 597 dam upper high centered over the TX panhandle will slowly migrate westward to the 4 corners region Friday and will remain there on Saturday. Hgts will rise from 594 dam today to 596 dam Saturday (591 dam is normal for this time of year). There will be pretty consistent onshore flow to the east varying diurnally from 2 mb in the morning to ~6mb in the afternoon. There will be actual offshore flow from the north each morning (strongest this morning) turning weakly onshore in the afternoon.
Most max temps will rise 4 to 6 degrees today (the Central Coast will cool a degree or two). With the exception of the Central Coast max temps today will range from the upper 70s to lower 80s across the nearshore areas; the mid 80s to lower 90s for the inland coastal sections; the mid 90s to 106 degrees for the vlys and 100 to 106 degrees for the low mtn elevations and far interior. These max temps are 6 to 12 degree above normal. Max temps will not change much Friday, except the Central Coast will see about 5 degrees of warming. There may be a degree or two of cooling Saturday, but it will hardly be noticeable.
The temperatures will compounded by the greater than normal humidity resulting from the warmer than normal sea sfc temps and weak monsoon flow. The higher humidity and powerful inversion created by the subsidence from the upper high will also bring much higher than normal overnight lows each night.
The combination of above normal daytime highs and overnight lows along with the higher humidities will create a dangerous environment as people's bodies (those without AC) will be heat stressed day and night with no real recovery period. For all of these reasons heat advisories are in effect through Monday evening. Please see the product LAXNPWLOX for all of the details.
There will be a few areas and times within the Advisory Area that will meet warning criteria, but the long-duration Advisory make for a less complicated and easier to understand message. The risk for heat illness is high, especially for sensitive groups like the very young, the very old, those without air conditioning, and those active outdoors.
The offshore push from the north will likely keep the low clouds away from the beaches south of Pt Conception, but the onshore flow to the east will bring the typical night through morning low clouds and fog to the Central Coast.
The offshore push from the north will bring gusty winds to southern Santa Barbara County, the I-5 Corridor, and the western Antelope Valley this afternoon and evening as well as Friday Night afternoon and evening. The SBA south coast will likely need another wind advisory tonight and possibly again Friday night.
The upper high's position over the 4 corners will put it in a position for some monsoon flow leading to afternoon mtn convection. At this time it looks like the chc is less than 10 percent, but it is not zero.
(Sun-Wed), 23/308 AM.
The upper high will begin to move back east on Sunday. More importantly there will be an increase in the onshore flow and possible return of some morning low clouds across the csts. The low but non-zero threat of monsoon convection will remain over the mtns. Max temps will drop a few degrees but advisory level heat will continue.
Hgts fall some on Monday as the upper high continues to move to the east. Onshore flow continues to increase. This will bring a few more degree of cooling. There may be enough cooling to consider dropping a few areas from the heat advisories, but for now its prudent to leave them all in through Monday evening.
More cooling on Tuesday should be enough to eliminate the heat threat. By next Wednesday highs will still be above normal but only by 3 to 5 degrees.
Mdls remain consistent showing another round of heat developing at the end of next week.
23/1010z.
At 0822Z at KLAX, the marine layer was 800 ft deep. The top of the inversion was at 2300 ft with a max temperature of 27 C.
High confidence in VFR TAFs for KPMD, KWJF, KBUR, & KVNY.
Moderate confidence in TAFs for KSMX and KSBP. VFR transition could be off by 1 hour.
Fair confidence in the remainder of the TAFs with a 25 percent chc of IFR/LIFR conds 12Z-16Z.
KLAX, Fair confidence in TAF. There is a 25% chance of OVC004 conds 12Z-16Z. No significant east wind component expected.
KBUR, High confidence in TAF.
23/210 AM.
Widespread Small Craft Advisory (SCA) NW winds will likely continue through the weekend across the Outer Waters, with seas nearing 10 ft at times. There is a 30% chance of Gale Force wind gusts this afternoon and evening across the Outer Waters. SCA winds will spread into the nearshore waters along the Central Coast and SB Channel at times through the forecast period.
23/210 AM.
A long period, southern hemisphere swell will arrive later this week and will add to the continuing swell from Hurricane Fausto.
As a result, Beach Hazard Statements for Los Angeles and Ventura county coastlines remain in effect through the weekend. Refer to CFWLOX & SRFLOX for more details.
The Eastern Pacific looks to remain active over the next couple of weeks. This could result in additional southerly swells to impact the coastline.
Ca, Heat Advisory remains in effect until 8 PM PDT Monday for zones 38-88-342>345-348-351>353-355>358-368>382-548. (See LAXNPWLOX). Heat Advisory now in effect until 8 PM PDT Monday for zones 349-350. (See LAXNPWLOX). Wind Advisory remains in effect until 6 AM PDT early this morning for zones 349-351-352. (See LAXNPWLOX). Beach Hazards Statement in effect through Sunday evening for zones 354-362-366. (See LAXCFWLOX). Heat Advisory in effect from 10 AM this morning to 8 PM PDT Monday for zones 354-362-366-367. (See LAXNPWLOX). Extreme Heat Warning in effect from 10 AM this morning to 8 PM PDT Monday for zone 383. (See LAXNPWLOX). PZ, Small Craft Advisory in effect from noon today to 3 AM PDT Saturday for zone 645. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Friday for zone 650. (See LAXMWWLOX). Small Craft Advisory in effect from 3 PM this afternoon to 9 PM PDT this evening for zone 655. (See LAXMWWLOX). Small Craft Advisory in effect until 3 AM PDT Saturday for zones 670-673-676. (See LAXMWWLOX).
