BASIC PATTERN:
Large Scale Pattern –
- Remainder of Jan: Predominantly dry for all of California. This is about equally true for both Jan and Feb. Warmer than normal conditions continue overall, but there will be some cold periods, especially in late Jan.
- February: Freezes in SOCAL and Central Calif early in Feb, then we turn to warmer days midmonth after a period of blustery cold fronts. Frosts continue unusually frequent in agricultural valleys during Feb.
- March: Somewhat dry in most of California, but with a chance for near normal precipitation in far N California Humboldt Co north, and in the mountains (northern Sierras, and Siskiyou’s). Above normal frost risk in NW California (Mendocino/Sonoma/Napa Co’s and near or above normal frost risk S Sacramento Valley and Central California. March 2022 appears unusually dry in SOCAL.
- Despite abundant and widespread snowfalls in the Sierras (Dec, but much lower amounts in Jan), the water budget deficit continues problematic into March.
- 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
Precipitation Trend: The main dates of precipitation are:
Main rains and mountain snows occur Jan 23-28, 31, Feb 3, Feb 6-8.
N and Central California Precipitation Dates- Jan 23-26, 31, Feb 3, Feb 6-9.
Forecast for Northern and Central California:
NORCAL Rains: Jan 23-28, 31-Feb 1, Feb 3-4 and 6-8.
CENTRAL CALIF Rains: Jan 24-27, Feb 1, 4, and 8-9.
WARM SPELLS: Jan 14-16, 22-23, 29-30, and Feb 12-14.
COLD SPELLS: Jan 24-26, 31-Feb 1, 3-5, and 6-10.
FRONTS WITH RAINS: Jan 23, 31, Feb 3 and 6.
FROST AND FREEZE: Jan 14-17, 27-28, Feb 2, 5, and 10-13.
Forecast for S California:
SOCAL RAINS: Jan 23-26, Feb 3 and 8-10.
SOCAL WARM SPELLS:. Jan 14-21, 29-30, Feb 8 and 13-16.
SOCAL COOL OR COLD SPELLS: Jan 23-27, Feb 3-8 and 9-11.
Frosts may follow on:. Jan 27-29, Feb 6-7 and 11-13.
FRONTS WITH RAINS:. Jan 23, 25, Feb 4 and 8.
Sierra Nevada:
Dates of mountain rains and snows are: Jan 23-28, 31-Feb 1, 4, and 6-8.
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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 Feb 1 – Mar 31, 2022:
Highlights: The CFSv2 model shows a return to near or a little above normal temperatures for SOCAL in Feb, and warmer/drier than normal for Mar. Best chances for freezes in Feb and Mar are in the dry cool airmasses behind cold fronts, after dry downslope winds diminish or subside. The CFSv2 model is suggesting a trend towards warmer than normal days in Mar. If this occurs, then frosts may become less frequent than normal.
Looking Ahead – Long Range Outlook
Feb 15 – Apr 15, 2022 - N and Central California:
Summary – N and Central California: We list here the trends from the North American MultiModel Ensemble (NMME) with regard to an overall statement on the upcoming frost season.
NORCAL and Central California: Below normal temperatures for both Feb and Mar 2022. Slightly below normal temperatures for Apr 2022. NMME results for April 2022 show near normal rain in the Delta and Northern California, and near normal temperature for Apr.
From CFSv2 numerical guidance: We return to a period of windy frontal passages with sparse or small rains during 15-22 Feb but again some frosts overnights. This is followed by dry and warmer days during 18-25 Feb, with recurring frosts and freezes at nights in valleys. Possible frontal passages with rains late Feb through the first week or two of Mar. A shift to near normal rainfall and Sierra snow again is possible during this wetter period in the first half of Mar. We suggest, from this scenario, that risk of frost in the Delta is seasonable up through late Mar.
Feb 15 – Apr 15. 2022 – For SOCAL mountains westward to coast:
Summary - Results from NMME for SOCAL Feb-Apr: Warmer than
normal. Drier than normal Feb and Mar, but near normal rainfall for April (a month of usually meager rainfall).
From CFSv2 numerical guidance: Feb will have near or below normal nighttime lows for S California, San Luis Obispo Co and south, and continued cool with some frosts/freezes. There is support for a continuation in frost/freeze frequency through most of Feb a few dry cold fronts maintaining cold dry airmasses into SOCAL coastal valleys.. The frost risk in Feb, and again in 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 troughs coming south through the Sierra Nevada and Great Basin into SOCAL and Arizona at times during Feb and again in Mar. There is not much rain for California in this pattern, but opportunity exists for frost and freeze in the prime late winter-early spring 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.
In summary, after the robust storms during Dec, and a possible up-tick of rains in early to mid March, and possibly in April, it appears that we are more likely to have a drier than normal ending to the rainy season, comprising Feb, Mar, and Apr.
(Terms and Definitions Used In This Weather Outlook)
Alan Fox & Zane Stephens...Fox Weather, LLC
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