BASIC PATTERN:
Large Scale Pattern –
- The latest version of CFSv2 outlook maps shows January with above normal rainfall for California. This is a change from previous outlook maps.
- First half of Jan: Still is a chance for above normal rainfall from troughs and forcing of troughs near the central - S California coast from weak MJO influence and support for troughing near N Baja California.
- January: Colder than normal N California, and near normal temperatures central Sierras. Above normal rains Siskiyou’s, North Coast and Plateau and N Sierras. Above normal snowfall in the central and S Sierras as well. Near normal temperatures SOCAL and SE California deserts->Arizona. For SOCAL… wetter than normal during first 10 days of Jan and briefly in late Jan, followed by a drier pattern in Feb.
- February: After a rain during the first few days of Feb, it turns very dry in all of California, including SOCAL. There is a chance for near normal rainfall in far N California, Siskiyou Mountains, and coast Humboldt Co north. Freezes in SOCAL and Central Calif early in the month during 4-7th, then turning to warmer days midmonth after a period of blustery cold fronts 9 Feb to mid month. Frosts continue unusually frequent agricultural valley areas through Feb.
- March: Somewhat dry in most of California, but with above normal precipitation in far N California Humboldt Co north, and in the mountains (northern Sierras, and Siskiyou’s). Near or above normal frost risk in NW California (Mendocino/Sonoma/Napa Co’s and near normal frost risk S Sacramento Valley and Central California. March 2022 appears unusually dry in SOCAL after some rains during 1-5th and 15th Mar.
- After subnormal rains last year, and some more dry periods during the rainy months this winter, the water budget deficit continues problematic, despite the Sierra snows of Dec and Jan.
- Recurrent NW flow from an area of colder than normal sea surface will tend to support more frequent frost/freeze events than usual for Jan and Feb, including SOCAL citrus and avocado regions.
FORECASTS FOR CALIFORNIA
- We shift to a predominantly cold and showery for most of Jan 2022, then drier than normal for 26-29 Jan.
- Precipitation Trend: : The main dates of precipitation are: Main rains and mountain snows occur Jan 3-5, 12-13, 22-25, Jan 30-Feb 3.
- N and Central California Dates of Precipitation- Jan 3-5, 12-13, 22-25, Jan 30-Feb 2
Forecast for Northern and Central California - Jan 2-Feb 3
NORCAL Rains: Jan 3-5, 12-13, 22-25, Jan 30-Feb 2.
CENTRAL CALIF Rains: Jan 4-5, 13, 23-25, Jan 31-Feb 2.
WARM SPELLS: Jan 9-11, 19-21, 28-29.
COLD SPELLS: Jan 2-5, 12-16, 23-26, Jan 30-Feb 4.
FRONTS WITH RAINS: Jan 3, 12, 22-24 and 31.
FROST AND FREEZE: Jan 5-8, 14-17, 25-28.
Forecast for S California – Jan 2-Feb 3
SOCAL RAINS: Jan 4-5, 12, 22, 24, 31. .
SOCAL WARM SPELLS:. Jan 7-11, 16-21, 29.
SOCAL COOL OR COLD SPELLS: Jan 3-6, 13-14, 22-26, 31-Feb 2
FRONTS WITH RAINS:. Jan 4-5, 12, 22, 24, 31.
Frosts may follow on:. Jan 3, 6-8, 13-15 and 26-28
Sierra Nevada - Jan 2-Feb 3
Dates of mountain rains and snows are: Jan 3-5, 12-13, 22-25, 30-31-Feb 1
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The listing of dates normally included for hot and cold spells, and precipitation are based on our CFSDaily and CFSDailyAI forecast products, and present expected trends in precipitation and temperature (CFSDailyAI) to 4km. Our system gives some consideration of terrain and coastal influence. We consider the CFSv2 as one of the better ways to represent basic weather down in the sub-monthly time scale beyond the 15 day GFS or monthly maps from CFSv2 or NMME.
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Southern California Deserts Outlook for Jan 2-31, 2022:
Highlights: Predominantly cold, and occasionally wet for the deserts is suggested for first week or two of Jan 2022. It appears to turn warmer during the last third of Jan following a midmonth showery period, and some freezes on 21-23 Jan. Best chances for freezes are in the dry cool airmasses behind cold fronts, after dry downslope winds subside.
Looking Ahead – Long Range Outlook
Feb 1 – Mar 31, 2022 - N and Central California:
Summary – N and Central California: Colder than normal is expected across northern and central California for Feb , and nightly frosts-freezes about Feb 1 – 8. We return to a period of windy frontal passages with sparse or small rains during 9-16 Feb but again some frosts overnights. This is followed by dry and warmer days during 18-25 Feb, with recurring frosts-freezes at nights. Possible frontal passages with rains late Feb through the first week of Mar. A shift to near or above normal rainfall and Sierra snow again is possible during this wet period during the first half of Mar. We suggest, from this scenario, that risk of frost in the Delta is seasonable up through late Mar.
Feb 1 – Mar 31. 2022 – For SOCAL:
Summary - Feb will have near or below normal nighttime lows for S California, San Luis Obispo Co and south, and continued cool with recurring frosts/freezes. There is support for a continuation in frost/freeze frequency in end of Jan and through Feb from dry cold fronts maintaining cold dry airmasses into SOCAL coastal valleys. The frost risk in Feb – early March includes counties of Ventura, interior Orange, Riverside, and interior San Diego as well. The southern deserts have decreased frost risk in latter Feb and Mar.
CFSv2 monthly guidance suggests some dry troughs coming south through the Sierra Nevada and Great Basin into SOCAL and Arizona at times during Feb and most of Mar. There is often not much rain for California in such patterns, but plenty of opportunity for frost and freeze in the prime cool-season food-crop areas of the southern deserts and western Arizona during non-windy periods. Again, the best chance of frost /freeze will be following dry cold frontal passages and after dry downslope winds subside. Cold inversions and subsequent freeze events develop more readily when winds are light and the air mass aloft is cool and dry.
(Terms and Definitions Used In This Weather Outlook)
Alan Fox & Zane Stephens...Fox Weather, LLC
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