Weather Outlook — February 28 - March 25, 2025

LARGE SCALE SUMMARY

1. NORCAL Rain dates from combined GFS, WRF, Fox Weather's MtnRT, and the CFSv2 text outlook issued Feb 25, 2025:  For Central California, Rain Dates in coastal valleys are mainly Mar 2-3, 9-12, 14-15, 18-19, 25-27, 29-31. Dates of main precipitation centers from CFSv2 are: Feb 28-Mar 1 showery. Mar 2-3 rain/showers, 4-5 (rain and showers), 7-10 light showers. 14-18 mostly light rain or showers.  Periods of moderate to local heavy rain are possible Mar 21-26.
2. Support for troughing continues in the central N Pacific from about 130-145W (mainly NE to N of Hawaii), and at 160W to near the Dateline is N to NW of Hawaii. SOCAL rains are possible on Mar 11, 14, 16.  Arizona rains are possible on Mar 22.
3. Most of the rains in March bypass Southern California. As usually occurs in spring, a few cutoff lows develop or move across SOCAL.
4. For forestry, the next wet spells appear for following dates— rains and snows Mar 2-3, 9-12, 14-15, and 18-19. In addition to the CFSv2, we also use GFS, WRF and our MtnRT maps based on GFS=>WRF.

NEAR TERM OUTLOOK — February 28 – March 25 

• NORCAL: Precipitation dates in coastal valleys are : Mar 2-3, 9-12, 14-15,1 8-19, 25. Mild/dry periods: Cool to near seasonally average temperatures. Cool periods occasional low snow levels: Mar 1, 2, 3. North Sierra Precipitation: Feb 28, Mar 1, 2, 3. Central Sierra Precipitation: Feb 28,Mar 1, 2, 3.
• Central California: Precipitation: Feb 28, Mar 1, 2, 3, 9-12, 14-15
  19. Mild dry periods alternate with cold and (snow in mountains), frosts/freezes mid March.
• Southern California: Precipitation Mar 1, 2, 3.  More rains occur in SOCAL about 15th Mar and again 22 Mar. Mostly light showers are suggested at this time. Several nights have freezes in the normally colder 
  valleys, on nights in which clearings occur for a time overnights/early mornings between fronts/rain events
• Southern California Deserts. Colder than average during rainy periods. Rainfall amounts below average. Rain dates in SOCAL Deserts: Mar 2-3, 15, 22.

MEDIUM TERM OUTLOOK:  March 25 - April 25

• North half of California: Near average precipitation with slightly colder than average. Frosts: greater number of frost/freezes than average.
• South half of California:  Below average precipitation with a near average temperature. Near to little above average number of frosts/freezes in valleys of SOCAL, especially north part, i.e. valleys of 
  San Luis Obispo, Santa Barbara, Ventura Counties. The Riverside Valley, Ramona(San Diego Co) areas will also dip briefly into the 30s.

LONG TERM OUTLOOK: Apr 25 — May 25 

• North half of California:  Near to a little above average precipitation, highest precipitation anomaly will be at the North Coast Mendocino Co north in first half of April.  Temperatures well above average Sacramento Valley, and well above average in central to southern Sierras (warm nights on slopes with inversion conditions). Frosts: greater number of frost/ freezes than average in mid Apr, recovering to near or a little above average number of frosts/freeze only slightly above average number of frosts/freezes by May 1.
• South half of California: Below average precipitation with above average temperature. We will still see some frosts in valleys of Southcentral California, including San Luis Obispo and Santa Barbara Coís.  Turning warmer than average in SOCAL mountain areas overnights (peaks and slopes due to inversion conditions as high pressure tends to build more frequently in late April to first week of May, even though valleys are still seasonably cool.

LONGER TERM OUTLOOK: May 25-June 30

• Northern California:  Temperatures recurrently above average for the early summer period, precipitation remaining below average. For valleys and mountains of Northern California, 
  Warmer and drier than average during late spring and first month of summer (June).     
• Southern California:  For the valleys of Southern California:  Warmer and drier than average during   late spring and the first month of early summer (June). 

Figures: Alan Fox, Text: Alan Fox, Fox Weather, LLC.

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