CNRFC - Hydrology - River Guidance - Graphical RVF

*** IMPORTANT *** Week of June 16 - Website Data Outage - Due to a major computer upgrade the week of June 16, nearly all data on the CNRFC web site will not be updated. We anticipate the down time to be approximately 4 days. The latest deterministic hydrologic forecasts for official forecast points will continue to be available at the National Water Prediction Service during this time.

Location:

SAN JOAQUIN RIVER - PATTERSON (PATC1)

Latitude: 37.49º N	Longitude: 121.08º W	Elevation: 97 Feet
Location: Stanislaus County in California		Bulletin Group: San Joaquin		River Group: San Joaquin

Issuance Time:

Jun 20 2025 at 11:22 AM PDT

Next Issuance:

Jun 21 2025 at 9:00 AM PDT

Action/Monitor: 48.0 Feet

Minor Flood: 54.7 Feet

Moderate Flood: 57.3 Feet

Major Flood: 58.3 Feet

Plot Type:

Please Note:
1) Each individual timeseries plotted on the graphical river forecast can be toggled on and off by clicking the legend entry above. If the "Observed (Raw Data)" contains bad data and is toggled off, the plot will scale to the remaining timeseries.

2) At extremely low river flows, the "Observed (Raw Data)" may show readings below the lower end of the available rating table, while the "Observed (Simulated)" will only show values at the bottom of the rating table, creating a potential discrepancy between the two readings.

Observed Data Credit
	Raw streamflow data is provided by the California Department of Water Resources. View California Department of Water Resources Data for this station location.

Historical Stage/Flow Data
Water Year	Peak Discharge (cfs)	Stage (feet)	Date
Most Recent 5 Years
2024	5,740	41.64	Mar 7, 2024
2023	24,500	52.24	Mar 27, 2023
2022	1,190	33.41	Dec 31, 2021
2021	1,770	34.50	Feb 1, 2021
2020	3,120	37.40	Oct 2, 2019
Historical High Stage/Flow Events (Period of Record - Oct 1969 to Present) - Ranked by Flow
1983*	28,700	51.26	Mar 4, 1983
2006*	27,612	50.97	Apr 10, 2006
2017	25,600	51.71	Feb 22, 2017
1980*	24,900	50.57	Feb 25, 1980
2023	24,500	52.24	Mar 27, 2023
1938*	--	50.50	Jun 13, 1938
1986*	23,000	49.65	Mar 18, 1986

* Discharge affected by regulation or diversion
** Most recent continuous record back to Oct 1969 with segmented periods back to Apr 1938

Location Photographs
Upstream Photo	Gage House Photo	Downstream Photo

ESRI™ Locator Map

Flood Impacts
58.3 Feet	Stages above 58.3 feet result in flooding outside the levee. Top of levee.

Official 7 Day National Weather Service Forecast (CAZ019)

Today: Sunny. Highs 74 to 84. Northwest winds up to 15 mph with gusts to around 30 mph.

Tonight: Clear. Lows 47 to 55. West winds 10 to 15 mph with gusts to around 35 mph.

Saturday: Sunny, breezy. Highs 74 to 84. Northwest winds 10 to 15 mph increasing to 15 to 25 mph in the afternoon. Gusts up to 35 mph.

Saturday Night: Clear. Lows 51 to 61. Northwest winds 10 to 20 mph with gusts to around 30 mph.

Sunday: Sunny. Highs 80 to 88. Northwest winds 10 to 15 mph with gusts to around 25 mph.

Sunday Night: Clear. Lows 52 to 58.

Monday: Sunny. Highs 85 to 93.

Monday Night: Clear. Lows 55 to 63.

Tuesday: Mostly sunny. Highs 86 to 94.

Tuesday Night through Thursday: Clear. Lows 54 to 64. Highs 87 to 97.

Product Disclaimer

This river graphic is not intended to serve as a substitute for official flood watches, warnings, advisories, or statements issued by the NWS Sacramento Weather Forecast Office. Observations are preliminary and subject to change. River levels identified as "forecast" should be consistent with those contained in official NWS products. River levels identified as "guidance" have significant uncertainty due to future weather or reservoir regulation and are provided for planning purposes only.

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Verification - Historical Graphical RVF
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