Station Name: MERCED R A HAPPY ISLES BRIDGE NR YOSEMITE CA
Data Source: Water Data - usgc.gov

Elevation Above Sea Level: 4,095 feet

Nearest Address:
Happy Isle Loop Rd
Yosemite Valley, CA 95389
Mariposa County

GPS Coordinates: 37.73131496, -119.5590514

Nearby Water Temperatures

Winter Storm Watch issued April 19 at 5:35PM PDT until April 22 at 5:00PM PDT by NWS Hanford CA

Effective: Sun April 19, 2026, 5:35 PM
Expires: Mon April 20, 2026, 2:00 AM

* WHAT...Heavy snow possible. Total snow accumulations 3 to 5 inches above 7,000 feet, with 12 to 18 inches possible at the highest elevations of the Sierra Nevada. Winds could gust as high as 75 mph along the Sierra crest. * WHERE...Kaiser to Rodgers Ridge, Kings Canyon NP, Sequoia NP, Upper San Joaquin River, and Yosemite NP outside of the valley. * WHEN...From late Monday night through Wednesday afternoon. * IMPACTS...Roads, and especially bridges and overpasses, will likely become slick and hazardous. Visibilities may drop below 1/4 mile due to falling and blowing snow. Travel could be very difficult to impossible. The hazardous conditions could impact the Tuesday morning and evening commutes. Strong winds could cause tree damage.

Monitor the latest forecasts for updates on this situation. Persons are urged to stay indoors until conditions improve. If you must go outside, dress in layers. Several layers of clothes will keep you warmer than a single heavy coat. Cover exposed skin to reduce your risk of frostbite or hypothermia. Gloves, a scarf, and a hat will keep you from losing your body heat. Persons should delay all travel if possible. If travel is absolutely necessary, drive with extreme caution and be prepared for sudden changes in visibility. Leave plenty of room between you and the motorist ahead of you, and allow extra time to reach your destination. Avoid sudden braking or acceleration, and be especially cautious on hills or when making turns. Make sure your car is winterized and in good working order.

Winter Storm Watch issued April 19 at 9:11AM PDT until April 22 at 5:00PM PDT by NWS Sacramento CA

Effective: Sun April 19, 2026, 9:11 AM
Expires: Mon April 20, 2026, 5:00 PM

* WHAT...Heavy snow possible above 5000 feet. Total snow accumulations of up to 12 to 18 inches, with up to 2 feet at the highest peaks. Minor accumulations of up to 2 inches possible down to 4500 feet. Southwest winds could gust as high as 50 mph. * WHERE...Sierra Nevada and southern Cascades above 5000 feet, including Highway 50, Interstate 80 and Lassen National Park. * WHEN...From late Monday night through Wednesday afternoon. * IMPACTS...Travel could be very difficult. The hazardous conditions could impact the Tuesday and Wednesday commutes. * ADDITIONAL DETAILS...Snow levels initially 6000 to 7000 feet Monday night, lowering to 5500 to 6500 feet Tuesday, and down to 4500 to 5500 feet Wednesday. Heaviest snowfall expected Tuesday afternoon and evening.

Check the latest road conditions from Caltrans online at quickmap.dot.ca.gov or dial 5 1 1.

Winter Storm Watch issued April 19 at 9:20AM PDT until April 22 at 5:00PM PDT by NWS Reno NV

Effective: Sun April 19, 2026, 9:20 AM
Expires: Mon April 20, 2026, 9:30 AM

* WHAT...Heavy snow above 8000 feet. Snow accumulations of 6 to 12 inches above 8000 feet with up to 18 inches on highest mountain peaks. Up to 4 inches of snow possible for communities along Highway 395. Wind gusts of 40 to 50 mph across lower elevations and up to 80 mph along ridges. * WHERE...Mono County. * WHEN...From Tuesday morning through Wednesday afternoon. * IMPACTS...Travel could be very difficult through Sierra passes. The hazardous conditions could impact the Tuesday and Wednesday commutes. Strong winds could cause damage to trees and power lines. * ADDITIONAL DETAILS...Strong and gusty winds are anticipated Monday and Tuesday with potentially damaging winds Tuesday afternoon. Heaviest snowfall expected late Tuesday morning through Tuesday afternoon. Locally greater snow totals are possible with heavier snow showers. Isolated lightning is also possible along the Sierra crest Tuesday and Wednesday afternoons.

Monitor the latest forecasts for updates on this situation.

Lake Wind Advisory issued April 19 at 12:07PM PDT until April 20 at 10:00PM PDT by NWS Reno NV

Effective: Sun April 19, 2026, 12:07 PM
Expires: Mon April 20, 2026, 10:00 PM

* WHAT...Southwest winds 10 to 20 mph with gusts up to 35 mph on northeast California and eastern Sierra lakes, including Lake Tahoe where wave heights of 1 to 3 feet are expected. * WHERE...Greater Lake Tahoe Area, Lassen-Eastern Plumas-Eastern Sierra Counties, and Mono County. * WHEN...From 11 AM to 10 PM PDT Monday. * IMPACTS...Small boats, kayaks and paddle boards will be prone to capsizing and should remain off lake waters until conditions improve. * ADDITIONAL DETAILS...Impacted lakes include Eagle Lake, Lake Davis, Frenchman Lake, Stampede and Boca reservoirs, Donner Lake, Lake Tahoe, Bridgeport Reservoir, Mono Lake, and Crowley Lake.

Check lake conditions before heading out and be prepared for a sudden increase in winds and wave heights. Consider postponing boating activities on the lake until a day with less wind.