Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
867 FXUS66 KLOX 220011 AFDLOX Area Forecast Discussion...UPDATED National Weather Service Los Angeles/Oxnard CA 411 PM PST Thu Nov 21 2024 .SYNOPSIS...21/146 PM. Increasing clouds but dry weather expected through Friday afternoon. Rain chances will develop along the Central Coast Friday evening then spread across Los Angeles and Ventura Counties Saturday. Another round of rain is expected later Sunday into Monday. && .SHORT TERM (TDY-SUN)...21/218 PM. A large and powerful cyclone continues to spin off the Pacific Northwest coast. It has been drifting west along 50N with smaller upper lows as far south as 40N pinwheeling around each other. This overall pattern is expected to remain through at least early next week. In the meantime southwest California will be on the very southern edge of a couple of rain bands that will move through the area starting later Friday. Most of the ensemble solutions continue to strongly favor low impacts locally. The first impulse Friday night into Saturday (LA County mainly late morning to mid afternoon Saturday), will be the weaker of the two. This will be a 2-5 hour period of light rain in most areas with rain rates under a tenth of an inch per hour and totals under a quarter inch (except upslope areas of NW SLO County and southwest SB County where amounts up to a half inch are possible. Sunday will be dry for most of the day except along the Central Coast when the next band of rain from this cyclone arrives in the late morning into the afternoon. .LONG TERM (MON-THU)...21/228 PM. After around a 24-36 hour period of little to no rain, a second and slightly stronger system will come through the area Sunday into Monday and possibly lingering into Tuesday, though the lions share of the rain falling later Sunday into Monday. Ensembles have trended weaker with this one, though still at least a little stronger than the first batch due to a stronger southerly flow component that will provide a slight boost to the rain amounts and rates as well as a longer duration of rain. As a result, upslope areas such as NW SLO County and southern Santa Barbara County could receive 1-2 inches of rain with peak rates around a third of an inch per hour. Still well below any thresholds for flooding or debris flows. Outside of the upslope areas, rain amounts of a half to one inch expected. While most of the system will be over by Monday evening, the area will remain in a moist westerly flow through Tuesday with off and on light rain possible through the day. Overall, a fairly gloomy damp day. Ensembles now show much lower rain chances for the latter half of next week with slowly warming temperatures, though still slightly below normal through the period. && .AVIATION...22/0009Z. At 2300Z at KLAX, there was no marine layer. There was a surfaced based inversion with a top at 1900 ft and a temperature of 20 C. Overall, moderate confidence in 00Z TAF package. For tonight into Friday morning at KPRB, KSMX, and KSBP, MVFR/IFR cigs are expected. There is a 40% chance for minimum cigs to be off by a category (LIFR flight cat possible). There is a 30% chance for cigs to become IFR at KOXR and MVFR at KCMA tonight. There is a 30% to 40% chance cigs become IFR or lower from 10z to 20z at KLGB. Arrival times of cigs/vsby restrictions may be off +/- 2 hours. Otherwise, high confidence in VFR conditions, and light winds expected. KLAX...Moderate confidence in 00Z TAF. There is a 30% chance of BKN005-BKN015 from 10z to 18z. No significant easterly wind component. KBUR...High confidence in 00Z TAF. && .MARINE...21/314 PM. Lingering areas of 10-11-ft seas warrant Small Craft Advisories (SCAs) across the northern and central Outer Waters (PZZ670/PZZ673) through early this evening. May consider short- lived SCA into tonight for the outer waters south of Point Mugu, as waves are reaching 10-11 feet over western portions. There will be a 20% chance for SCA winds over PZZ670 and northern PZZ673 Friday afternoon and evening. Otherwise, SCA conditions are unlikely across the coastal waters through next week. Areas of light rain will occur at times this weekend through next week. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 9 PM PST this evening for zones 670-673. (See LAXMWWLOX). && $$ PUBLIC...MW AVIATION...Black MARINE...Cohen SYNOPSIS...MW weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox