Real-time Insights on the February 12-14 Precipitation Event

The seventh significant weather event of the water year was geographically extensive and brought significant rain and snow throughout the state (see radar image). The coastal regions saw the greatest impact in terms of % WY accumulation.

Event Analysis

We can assess the February 12-14 storm's impact using near real-time National Weather Service data. Be reminded, this data set is not fully representative and provides only an estimate of WY precipitation totals. 

Regional Highlights:

• ‍Region 1 (LKLA): No station data was reported for the Lower Klamath region during this event.
• ‍Region 2 (SYFA): The Sacramento, Yuba, Feather and American region had a 5.60% increase in WY precipitation from February 12-14. Sacramento and Blue Canyon Airports gained 7.00 and 8.47 percentage points, respectively.  While Redding only gained 3.22%, it has the highest total WY percentage from the Region 2 stations, with 91.35% of normal.

• Region 3 (RNSF): The San Francisco Bay area gained 9.29%, nearly identical to the event accumulation from the Feb 2-4 storm only 10 days before.  The station at San Jose International Airport gained nearly 12 percentage points in WY accumulation from the event.  Santa Rosa added another 2.64 inches, reaching an impressive 109.38% of WY normal—still the highest total WY percentage across all reporting stations.
• Region 4 (SNJQ, TBVL):  Precipitation totals in the San Joaquin and Tulare region rose by 8.34%.  Stockton received 1.41”, the most significant accumulation in the region, representing a gain of 10.48 percentage points.  ‍
• Regions 5 (CENT): The Central California Coast was a close second (to MJVE, discussed below) in terms of event impact, gaining 14.21 percentage points from February 12-14.‍
• Region 6 (KTKK): The Kern & Kings regions saw a 6.17% gain from this event.‍
• Region 7 (SCAL, MJVE):  Southern California and the Mojave Regions gained 10.51 and 14.43% of WY total from February 12-14. This was the most significant precipitation event for Region 7 so far this year (see plot below).

Water Year Perspective

The graph below highlights the impact of each significant precipitation event this water year, providing a clear view of each storm’s magnitude and reach within the broader context. The February 12-14 storm was the first of the water year to deliver significant precipitation across all eight NWS regions, increasing water year accumulation by at least 5% in each. Notably, Southern California and the Mojave (NWS Regions 7 and 8) saw their most substantial precipitation of the season. This was only the second time these regions received impactful precipitation, providing a much-needed boost in an otherwise drier-than-average start to the water year in the south.
‍

Some Relief for Southern California

This event is helping to improve drought conditions in central and southern California. The side-by-side drought conditions from before the event (2/11/25) and after (2/18/25) illustrate the change. The extent of extreme (red) and severe (orange) drought has noticeably decreased, especially in central and southern California, while moderate (yellow) and abnormally dry (light yellow) areas have expanded, replacing more severe conditions and signaling a shift toward drought relief.
‍

Northern Sierra, San Joaquin, and Tulare Basin

The 8-station, 5-station, and 6-station indices shown below provide insight into how the Feb 12-14 storm event impacted these regions. This year’s analogs (2017-18 and 2018-19) are shown alongside the current water year in each plot, with the timing of the Feb 12-14 event marked by a vertical red bar. 
‍

All three regions experienced a boost in precipitation during this period:  The Northern Sierra gained around 5.5 inches, the San Joaquin 6 inches, and the Tulare around 5 inches.  WY totals give perspective to these numbers: 

• The 8-station WY average is 53.20 inches; an approximate gain of 5.5 inches represents ~10%. 
• The 5-station WY average is 40 inches; a gain of 6 inches is ~15%.  
• The 6-station WY average is 28.3 inches; a gain of 5 inches represents an impressive ~18%. 

It’s interesting to note the accumulation curves for the current year falls between the analog years in the San Joaquin and the Tulare Basin.  In the Northern Sierra, the current year just slightly exceeds 2018-19.  We will investigate these patterns in more detail in the upcoming monthly report.