BASIC PATTERN:
Large Scale Pattern –
- The support for active rain events in eastern North Pacific and in California will greatly decrease beginning 19-20th. A dry period will tend to maintain itself through the end of Jan.
- We note that the sea surface temperature anomalies and IVTinit continue a warm moist pattern across the Pacific from 170W to 120W…30-35N. There is support for troughing from the N California coast and Oregon WSW-ward.
- Precipitation Trend: Mainly dry through Jan 31. Rain dates in Feb: 2-6, 13-17, 18, 23-24.
- In Feb 2023, from NMME and CFSv2 models, there is a tendency for below normal temperature in N California. Above normal precipitation occurs in Humboldt-Del Norte Co’s of NW California, and the northern mountains area (Siskiyou’s). Consistently dry conditions are suggested for S California.
- March 2023 looks currently (from NMME Model) colder than normal, but with a chance for about normal snowfall for the NORCAL mountains, including N Sierras, NORCAL coastal mountains, the NE Plateau, and N Sierras per the NMME model.
- Precipitation anomaly drifts back to near normal in Apr and May. Daytime temperatures return to near or a little above normal in Apr-May, while nights are cold and tend to be clearer than usual, with risk of frosty nights in frost-prone valley areas.
FORECASTS FOR CALIFORNIA
Forecast for Northern and Central California:
Norcal PRECIPITATION: Jan 30-31, Feb 1-2,6, 12-15, 16-17, 22 and 24.
Norcal MILD SPELLS: Jan 23-24, 28, Feb 9-11 and 19-21.
Norcal COOL SPELLS: Jan 30-Feb 7, 12-18 and 22-24.
Norcal WINDS (dry cold winds): Feb 2, 5-7, 13-15, 17-18 and 23.
Norcal FROSTS/FREEZES: Jan 20-24, Feb 7-9, 18-20, 23 and 25.
Central Calif PRECIPITATION: Jan 30-31, Feb 1-6, 12-15, 16-17 and 20.
Central Calif MILD SPELLS: Jan 23-25, Feb 9-11 and 19.
Central Calif COOL SPELLS: Jan 30-31, Feb 1-7, 12-18 and 20-21.
Central Calif DRY COLD WINDS/FREEZE RISK: Jan 20-24, Feb 7-9 and 18-19.
Forecast for Southern California:
SOCAL RAINS: Feb 3-6, 14-16, 23-24.
SOCAL MILD TO WARM SPELLS: Jan 23-25, Feb 4, 10-11, 19 and 23-24.
SOCAL COOL OR COLD SPELLS: Jan 31-Feb 3, 5-8, 12-17 and 20-22.
SOCAL FROSTS/FREEZES: Jan 20-24, Feb 3-4, 9-10, 15, 18-19 and 22.
SOCAL SANTA ANAS: Jan 20-21, Feb 3-4, 9-10, 15, 18-19 and 22-23.
Forecast for Central Sierra Nevada:
Central Sierra Nevada Precipitation: Dates of rain or snow: Feb 1-6, 13-17, 23-24.
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The listings of dates normally included for hot and cold spells, and precipitation are very approximate. They are based on our CFSDaily and CFSDailyAI products; and present expected trends in precipitation and temperature (CFSDailyAI) to 4km. Our system gives some consideration to 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 April and May 2023
Highlights: Showery and breezy at times. Usual risk of frost during clear periods of early April, but cool breezy nights in April and May. Some showers are possible in late Apr and early to mid May.
Looking Ahead – Long Range Outlook - April 1 - May 31, 2023
NORCAL and Central California coastal valleys, and Central Valley: Drier than normal through the region in April. Near normal rainfall is indicated for May in most areas, with a few spots a little wetter than normal. In general, NMME has been appearing a little drier than the CFSv2 for California as a whole.
For SOCAL mountains westward to coast: This period currently appears about normal temperature in Apr seasonably cold with above normal risk of frost and freeze and freeze will increase if the pattern dries out. Precipitation in mountains and deserts...below normal for most areas except near normal in some mountain spots. Watch for above normal frequency of Santa Anas in Apr, warm days but abnormally cold nights. This forecaster is not confident in going for a drier than normal Apr and May. March appears to be colder than normal with repeated cold spells. The unusually cold and dry events (frost-freeze) in Apr for Central California may affect challenge to the water supply during the spring frost protection season in Arroyo Grande and the Paso Robles areas, and viticultural areas in the interior southern Salinas Valley.
(Terms and Definitions Used In This Weather Outlook)
Alan Fox & Zane Stephens...Fox Weather, LLC
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