The Great California Storm of April 19-23, 1880

The Great California Storm of April 19-23, 1880

Could a single big late–season storm have a significant impact on the California drought? A 'Hail Mary' storm event? Normally by this time of the year (April 10th) California would have already received at least 90% of its rainy-season precipitation total and any additional rain or snowfall would have little impact so far as the current drought is concerned. However, back in late April 1880, one of the most intense storms ever to pound the state occurred. Here are the details.

One the wettest storms in central California history occurred on April 20-23, 1880. This was an extraordinary storm: Sacramento experienced its greatest 24-hour rainfall on record when 7.24” fell on April 20-21 and its two-day total was an astonishing 8.37” and, with a storm total of 8.81”, these are all still-standing records for the city.



Accumulated rainfall curve for Sacramento, California during the great storm of April 19-21, 1880. This remains the city’s greatest rainstorm on record. Source: Meteorology of Hydrologically Critical Storms in California, Hydrometeorological Report No. 37.

Sacramento’s 14.02” total for the month of April 1880 is the 2nd greatest monthly total for any month of the year since their records began in 1850. San Francisco was on the southern edge of the heaviest precipitation band but still picked up an impressive 3.20” on April 20-21 and 6.43” for the week of April 14-21. Its monthly total of 10.06” remains its wettest April on record since measurements began in 1850. In Napa Valley, north of San Francisco, an amazing 14.70” fell in 24 hours at Mt. St. Helena and 14.70” was also measured at Helen Mine further north. These figures still stand as the greatest April 24-hour rainfalls in California records. Other storm totals included 11.42” at Nevada City, 10.28” in Grass Valley (both in the Sierra foothills northwest of Sacramento), and 9.72” at Healdsburg, 8.88” in St. Helena (Napa Valley), and 7.34” in San Rafael (Marin County).



Isohyetal map of central California for the April 19-22, 1880 storm event. Southern California received much lighter amounts with Los Angles reporting just 1.43” in 24 hours on April 22-23. Source: Meteorology of Hydrologically Critical Storms in California, Hydrometeorological Report No. 37.

In the Sierra Nevada snow accumulations were off the charts. An amazing 194” (over 16 feet!) of snow fell at the railway depot Norden on April 20-23 at an elevation of about 7500’. If this figure was true, it would constitute the greatest single-storm snowfall on record for the contiguous U.S. The snow was so heavy it collapsed snow sheds over the railway near Summit (Donner Pass area). Summit depot itself recorded 298” (almost 25 feet) of snow during the month of April 1880, Emigrant Gap totaled 201”, and Truckee 124”. It is not clear how much of these totals were generated during the storm itself but it is likely a majority of the monthly snow totals were derived from the April 19-23 event. There were reports of Sierra streams disappearing as snow slides filled streambeds at higher elevations.

Synoptically, this was a high-latitude cold storm that originated in the Gulf of Alaska and came ashore in northern California on April 20th with a minimum pressure of around 1002 mb. The center of the low continued to intensify (to 998 mb) after moving inland (a very rare occurrence) to a position near Red Bluff where it made a small loop before filling in over the course of the following 24-36 hours. Although this was a ‘cold’ storm, the prodigious amounts of precipitation indicate that the system must have tapped into a sub-tropical flow of moisture from the Pacific (a so-called ‘atmospheric river’).



The estimated track of the low and its frontal positions during the storm of April 19-23, 1880. Source is Hydrometeorological Report No. 36, Washington D.C., October 1961.





Sea level synoptic charts for the period of 4 a.m. PT, April 20th to 4 a.m. PT April 22nd. Source: Meteorology of Hydrologically Critical Storms in California, Hydrometeorological Report No. 37.

One of the other unusual characteristics of the storm was how cold it was for a system so late in the season. The snow level was 3500’ at the beginning of the storm on April 20th, rose to 5700' at one point on April 21st, and then fell back to 4000’ towards the end of the storm.

So, if something like this storm were to happen this year, what impact would it have on the current drought? Obviously it would have a major impact given the huge amount of snow that fell in the Sierra. At the lower elevations, it would bring the seasonal precipitation up to normal levels for the northern half of the state. Unfortunately, the odds of such an event occurring are slim at best. According to the publication Historic Rainstorms of California, published by the California Department of Water Resources in 1997, the 1880 storm was a once in 2000-year event for Sacramento.

REFERENCES:

Meteorology of Hydrologically Critical Storms in California Hydrometeorological Report No. 37, U.S. Dept. of Commerce, Weather Bureau, Washington D.C., December 1962. Report prepared by Robert Weaver.

Historic Rainstorms in California: A Study of 1,000-Year Rainfalls California Department of Water Resources, Sacramento, California, August 1997.

Interim Report: Probable Maximum Precipitation in California Hydrometeorological Report No. 36, (reprinted with revisions of October 1969) Washington D.C., October 1961.

Christopher C. Burt
Weather Historian