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Yosemite National Park Monday, April 21st, 2018

aily Report - Yosemite National Park
Monday, April 21st, 2018
Today: Sunny. Highs 71 to 79 at 5000 feet...59 to 67 at 8000 feet.
Tonight: Mostly clear. Lows 39 to 49 at 5000 feet...28 to 38 at 8000 feet.
Tomorrow: Sunny. Highs 72 to 80 at 5000 feet...62 to 68 at 8000 feet.
Additional Point Forecast Weather Links:
YARTS Schedule Affected by Construction April 23-25
Construction on El Portal Road and Northside Drive will impact YARTS service this week. Due to the closure of Northside Drive, YARTS buses will not stop at the Visitor Center and (The) Majestic Yosemite Hotel. All visitors and employees must use stops at Half Dome Village and Yosemite Valley Lodge. Specific adjustments to arrival and departure times are subject to delays caused by construction and traffic congestion.  (J. Donovan)
Yosemite Valley Flood Narrative
On April 7th, Yosemite Valley experienced the 8th largest flood recorded at Pohono Bridge since 1917, the largest flood in 21 years. The Merced River peaked at Pohono Bridge at 6:15pm at 13.73 feet, flowing at 12,200 cubic feet per second (cfs). Upstream at the gage at Happy Isles, the Merced River peaked at 3:45pm at 10.09 feet, flowing at 8,000 cfs, which was the 6th largest on record at this gage since 1916. During the river’s peak, more than 60% of the river’s flow entered Yosemite Valley at Happy Isles, with the rest coming mainly from the numerous tributaries flowing into the valley. At Pohono Bridge, flood conditions occurred for nearly 30 hours, rising above 10 feet on April 7 at 08:00am and dropping below 10 feet on April 8 at 1:45pm. Floodwater inundated roads at numerous places, water depths ranged 2 - 4 feet at Chapel Meadow, Wosky Pond, Sentinel Cross, and El Cap Cross. 
The flood resulted from an unusual Spring atmospheric river of warm precipitation falling on a saturated snowpack and saturated soils. With the snowline higher than 12,000 feet, most of the precipitation falling in the Tuolumne and Merced River watersheds fell as rain. This combination of preexisting conditions and high snowline led to rapid runoff from most of the watershed area, generating flooding with only 2 – 4 inches of precipitation. This scenario differs from typical winter storms when the snowline is lower and a much smaller area of the watershed is contributing runoff. 
Interestingly, during rain-through-snow events it is generally thought that rain contributes most of the runoff, while smaller amounts of runoff are contributed by melted snow. However, during this storm, snow sensors in Yosemite measured larger amounts of snowmelt, in some places possibly doubling the amount of runoff. The amount of rain during the event ranged 2 – 4 inches, while snowmelt ranged 0.7 – 4.3 inches of liquid water.  During the afternoon of April 7, winter rangers in Tuolumne Meadows observed the Tuolumne River melting out rapidly, which was last observed during the historic flood of 1997. We are still investigating why such a large amount of snowmelt occurred.  (H. Forrester)
Room(s) for Rent
Rooms for rent in a beautiful, large 4+ bed/2.5 bath home, nestled in the hills off the 140, near the border of Mariposa and Midpines. Home is on 5 quiet acres, surrounded by great views which you can see from bedroom windows. $550/month per room, plus a portion of utilities. Email if you're interested.  (K. Indigo)
Scheduled Power Outage Wawona April 24 & 26
PG&E will be performing scheduled maintenance in the Wawona area. There will be 2 temporary short outages:
Tuesday April, 24th, 8:30am-9am
Thursday April 26th, 4pm-4:30pm
For more information contact Heather Gonzales, PG&E Outage Coordinator, at 726-5588.  (K. Bablitch)
Yosemite Valley Road Work
Final paving on Northside Drive between Bank 3-Way (Sentinel Dr.) and Camp 4 is planned for Monday April 23rd through Wednesday April 25th. The road segment will close and there will be temporary 2-way detours on Northside and Southside Drives. Shuttle bus routes from Yosemite Lodge will evolve throughout the 3 days. On Monday, shuttle buses will not be able to run east from the Yosemite Valley Lodge to Yosemite Village (instead they will head west to Pohono Bridge and circle back on Southside Drive). There may be short windows on Tuesday and Wednesday when shuttle buses may be able to travel east from the lodge. The next week, April 26th through April 30th, there will be two-way traffic through the area with short delays to finalize utility access points.
Contractors will pave the Yosemite Falls Parking area from April 26th through May 4th. Contractors will pave the Camp 4 Parking area May 7th and 8th.
Visitors may park at the Yosemite Falls and Yosemite Village parking lots. In addition, parking at Camp 4 and Yosemite Falls Parking areas will open in selected parking bays this Friday at the close of the work day through Wednesday, May 2nd. This parking is for day use only with the exception of Camp 4 campers.  (L. Acree)
Southside Drive Delays April 23-27
From Monday April 23rd thru Friday April 27th crews will be completing geotechnical borings at Pohono Bridge and Happy Isles Bridge as part of a bridge preservation project in Yosemite Valley.  There will be single lane traffic control with flaggers so please use caution when traveling through the construction zone. This work is scheduled to be complete in one week, by Friday, April 27th. The following delays should be anticipated while traveling across these two bridges next week:
Monday thru Friday
6am to 5:30pm –  Traffic delays up to 15 minutes  (M. Pieper)
Caltrans Construction Update For SR 49 and Surrounding Area
Caltrans advises that damage to State Routes (SR) 49 and 132, sustained after heavy rains on March 22nd, resulted in long term closures. SR 49 is closed for 36 miles between SR 120 and Bear Valley Road. SR 132 is closed for one half mile between Granite Springs and Piney Creek Roads. Completion dates are unknown at this time. Additionally, a Caltrans contractor has begun repaving 34 miles of SR 108 and SR 120 in Tuolumne County. Work began on April 2nd and is expected to continue into October. Motorists can expect lane closures and one-way traffic control, with flaggers and 10-minute delays.  (J. Donovan)
Northside Drive Traffic Pilot Beginning April 13th
Beginning late Friday morning, April 13th, Northside Drive will be reconfigured as a one-way two lane road at the Lower Falls intersection for westbound traffic. Traffic from Camp 4 and the Yosemite Falls Parking area will use Lodge Drive to head back to the Lower Falls intersection. There a right turn heads east on Northside Drive toward Yosemite Village. As a reminder, Lodge Drive is signed with a speed limit of 15 MPH. The goal of this pilot is to improve pedestrian safety and the overall efficiency of the Lower Falls intersection.  (J. Hoeflich)
Glacier Point Road
Road crews have begun snow removal operations on the Glacier Point Road beyond Badger Pass. The gate at Chinquapin is now closed and locked. There is no public access. Administrative Access will be authorized only between Chinquapin and Badger. Recreational activities such as bicycling will not be allowed on the road during this time.  (E. Scott)
El Portal Road Delays Update 3/28
Crews have re-mobilized to finish working on the storm damage repairs from last year.  Delays will continue up to Memorial Day weekend. Crews will be working on the El Portal Road between the western Park boundary (Yosemite View Lodge) and the Big Oak Flat Intersection. There will be single lane traffic control with flaggers and pilot car operations, so please use caution when traveling thru the construction zone. This work is scheduled to be completed by Memorial Day weekend. The following delays should be anticipated while traveling the El Portal Road between the western park boundary and the Big Oak Flat Intersection:
Monday thru Friday
6am to 8am –  Traffic delays up to 15 minutes
8am to 3:30pm -- Traffic delays up to 30 minutes
3:30pm to 5:30pm -- Traffic delays up to 15 minutes  (M. Pieper)
Museum/District Building Electrical Rehab Project
This project will rehabilitate the electrical system in the Museum/District Building by installing grounding in the existing electrical circuits. The Contractor mobilized on Monday, December 18th and the project is expected to run for 6 months. The 8 parking stalls to the west of the building between the sidewalk on the south and the south end of the fence to the north will become the Contractor's staging areas.  (K. White)