National Weather Service California Nevada River Forecast Center Department of Commerce National Oceanic and Atmospheric Administration National Weather Service

*** 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.
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MERCED RIVER - YOSEMITE NP AT HAPPY ISLES (HPIC1)
Latitude: 37.73º NLongitude: 119.56º WElevation: 4017 Feet
Location: Mariposa County in CaliforniaBulletin Group: San JoaquinRiver Group: San Joaquin
Issuance Time: Jun 16 2025 at 6:03 AM PDTNext Issuance: Jun 17 2025 at 9:00 AM PDT
Action/Monitor: N/A Minor Flood: 7.5 FeetModerate Flood: 10.0 FeetMajor Flood: 13.27 Feet

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
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Raw streamflow data is provided by the US Geological Survey (USGS).
View US Geological Survey (USGS) Data for this station location.

Verification - Historical Graphical RVF
Month:  
Day:  
Year:  
Cycle:  
To view other verification locations, use our Historical Graphical River Forecast Interface.
Historical Stage/Flow Data
Water Year
Peak Discharge (cfs)
Stage (feet)
Date
 Most Recent 5 Years
2024
2,980
6.80
May 19, 2024
2023
4,980
8.42
May 23, 2023
2022
2,430
6.25
Oct 25, 2021
2021
1,410
5.02
May 7, 2021
2020
2,160
5.96
Apr 30, 2020
 Historical High Stage/Flow Events (Period of Record - Aug 1915 to Present) - Ranked by Flow
1997
10,100
13.27
Jan 2, 1997
1956
9,840
12.73
Dec 23, 1955
1951
9,260
11.55
Nov 18, 1950
Location Photographs
ESRI™ Locator Map
Flood Impacts
13.27 FeetFlood of Record: 1/2/97. $178 million in damage to Yosemite Valley.
10.0 FeetNorthside Drive at Wosky Pond, Southside Drive at Chapel Meadow, El Capitan crossover, and Sentinel crossover are impassable to vehicles.
8.2 FeetSwinging Bridge overtops. Water on road at Northside Drive, Southsie Drive, El Capitan crossover, and Sentinel crossover.
7.5 FeetFlood Stage. Housekeeping camp and Yosemite Valley backpacker campground begin to flood.
7.0 FeetNorth Pines and Lower Pines campgrounds begin flooding.
Official 7 Day National Weather Service Forecast   (CAZ324)
Today: Sunny. Highs 65 to 79. South winds up to 10 mph increasing to southwest 15 to 20 mph in the afternoon.

Tonight: Colder, clear. Lows 43 to 49. Southwest winds 5 to 15 mph shifting to the north up to 5 mph after midnight.

Saturday: Sunny. Highs 59 to 71. Southwest winds up to 10 mph shifting to the west in the afternoon.

Saturday Night: Clear. Lows 42 to 50. West winds 10 to 15 mph shifting to the northeast after midnight.

Sunday: Warmer, sunny. Highs 65 to 77. Southeast winds up to 5 mph shifting to the southwest 5 to 15 mph in the afternoon.

Sunday Night: Clear. Lows 48 to 56.

Monday through Tuesday Night: Mostly clear. Highs 69 to 84. Lows 51 to 62.

Wednesday through Thursday: Clear. Highs 77 to 91. Lows 57 to 65.
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 San Joaquin Valley-Hanford 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.