MERCED RIVER - YOSEMITE NP AT HAPPY ISLES (HPIC1)
Latitude: 37.73º NLongitude: 119.56º WElevation: 4017 FeetForecast Type: Official Location
Location: Mariposa County in CaliforniaBulletin Group: San JoaquinRiver Group: San Joaquin
Issuance Time: Apr 21 2026 at 1:28 PM PDTNext Issuance: Apr 22 2026 at 9:00 AM PDT
Action/Monitor: N/A Minor Flood: 7.5 FeetModerate Flood: 10.0 FeetMajor Flood: 13.27 Feet

# Tabular Observed and Forecast Hydrograph Information
#
# Location: Merced River - Yosemite NP at Happy Isles (HPIC1)
#
# File Generation Time:  04/21/2026 at 01:28 PM PDT
# Data Interval:  1 Hour
#
# Most Recent Date & Time of Maximum Observed:  04/19/2026 at 06:00 AM PDT
# Maximum Observed Stage:                       3.78 Feet
# Maximum Observed Flow:                        681 cfs
#
# Earliest Date & Time of Maximum Forecast:     04/25/2026 at 11:00 PM PDT
# Maximum Forecast Stage:                       3.99 Feet
# Maximum Forecast Flow:                        785 cfs
#
# OBSERVED
#
# Date & Time  (Local)    Stage (Feet)     Flow (cfs)     Trend     Observed Status
# ---------------------------------------------------------------------------------
  04/16/2026 01 PM PDT            3.66            626                        Normal
  04/16/2026 02 PM PDT            3.64            617         -              Normal
  04/16/2026 03 PM PDT            3.63            612         -              Normal
  04/16/2026 04 PM PDT            3.63            612         0              Normal
  04/16/2026 05 PM PDT            3.62            608         -              Normal
  04/16/2026 06 PM PDT            3.61            603         -              Normal
  04/16/2026 07 PM PDT            3.67            630         +              Normal
  04/16/2026 08 PM PDT            3.69            639         +              Normal
  04/16/2026 09 PM PDT            3.71            649         +              Normal
  04/16/2026 10 PM PDT            3.76            672         +              Normal
  04/16/2026 11 PM PDT            3.75            667         -              Normal
  04/17/2026 12 AM PDT            3.75            667         0              Normal
  04/17/2026 01 AM PDT            3.76            672         +              Normal
  04/17/2026 02 AM PDT            3.75            667         -              Normal
  04/17/2026 03 AM PDT            3.74            663         -              Normal
  04/17/2026 04 AM PDT            3.75            667         +              Normal
  04/17/2026 05 AM PDT            3.72            653         -              Normal
  04/17/2026 06 AM PDT            3.71            649         -              Normal
  04/17/2026 07 AM PDT            3.69            639         -              Normal
  04/17/2026 08 AM PDT            3.67            630         -              Normal
  04/17/2026 09 AM PDT            3.68            635         +              Normal
  04/17/2026 10 AM PDT            3.65            621         -              Normal
  04/17/2026 11 AM PDT            3.56            581         -              Normal
  04/17/2026 12 PM PDT            3.58            590         +              Normal
  04/17/2026 01 PM PDT            3.57            586         -              Normal
  04/17/2026 02 PM PDT            3.55            577         -              Normal
  04/17/2026 03 PM PDT            3.56            581         +              Normal
  04/17/2026 04 PM PDT            3.60            599         +              Normal
  04/17/2026 05 PM PDT            3.55            577         -              Normal
  04/17/2026 06 PM PDT            3.54            573         -              Normal
  04/17/2026 07 PM PDT            3.54            573         0              Normal
  04/17/2026 08 PM PDT            3.55            577         +              Normal
  04/17/2026 09 PM PDT            3.61            603         +              Normal
  04/17/2026 10 PM PDT            3.62            608         +              Normal
  04/17/2026 11 PM PDT            3.65            621         +              Normal
  04/18/2026 12 AM PDT            3.67            630         +              Normal
  04/18/2026 01 AM PDT            3.69            639         +              Normal
  04/18/2026 02 AM PDT            3.70            644         +              Normal
  04/18/2026 03 AM PDT            3.71            649         +              Normal
  04/18/2026 04 AM PDT            3.72            653         +              Normal
  04/18/2026 05 AM PDT            3.68            635         -              Normal
  04/18/2026 06 AM PDT            3.69            639         +              Normal
  04/18/2026 07 AM PDT            3.69            639         0              Normal
  04/18/2026 08 AM PDT            3.70            644         +              Normal
  04/18/2026 09 AM PDT            3.67            630         -              Normal
  04/18/2026 10 AM PDT            3.64            617         -              Normal
  04/18/2026 11 AM PDT            3.64            617         0              Normal
  04/18/2026 12 PM PDT            3.62            608         -              Normal
  04/18/2026 01 PM PDT            3.62            608         0              Normal
  04/18/2026 02 PM PDT            3.60            599         -              Normal
  04/18/2026 03 PM PDT            3.59            594         -              Normal
  04/18/2026 04 PM PDT            3.58            590         -              Normal
  04/18/2026 05 PM PDT            3.54            573         -              Normal
  04/18/2026 06 PM PDT            3.55            577         +              Normal
  04/18/2026 07 PM PDT            3.56            581         +              Normal
  04/18/2026 08 PM PDT            3.60            599         +              Normal
  04/18/2026 09 PM PDT            3.62            608         +              Normal
  04/18/2026 10 PM PDT            3.65            621         +              Normal
  04/18/2026 11 PM PDT            3.70            644         +              Normal
  04/19/2026 12 AM PDT            3.73            658         +              Normal
  04/19/2026 01 AM PDT            3.74            663         +              Normal
  04/19/2026 02 AM PDT            3.75            667         +              Normal
  04/19/2026 03 AM PDT            3.76            672         +              Normal
  04/19/2026 04 AM PDT            3.74            663         -              Normal
  04/19/2026 05 AM PDT            3.76            672         +              Normal
  04/19/2026 06 AM PDT            3.78            681         +              Normal
  04/19/2026 07 AM PDT            3.77            677         -              Normal
  04/19/2026 08 AM PDT            3.75            667         -              Normal
  04/19/2026 09 AM PDT            3.76            672         +              Normal
  04/19/2026 10 AM PDT            3.73            658         -              Normal
  04/19/2026 11 AM PDT            3.71            649         -              Normal
  04/19/2026 12 PM PDT            3.72            653         +              Normal
  04/19/2026 01 PM PDT            3.68            635         -              Normal
  04/19/2026 02 PM PDT            3.68            635         0              Normal
  04/19/2026 03 PM PDT            3.69            639         +              Normal
  04/19/2026 04 PM PDT            3.64            617         -              Normal
  04/19/2026 05 PM PDT            3.64            617         0              Normal
  04/19/2026 06 PM PDT            3.62            608         -              Normal
  04/19/2026 07 PM PDT            3.62            608         0              Normal
  04/19/2026 08 PM PDT            3.61            603         -              Normal
  04/19/2026 09 PM PDT            3.63            612         +              Normal
  04/19/2026 10 PM PDT            3.64            617         +              Normal
  04/19/2026 11 PM PDT            3.66            626         +              Normal
  04/20/2026 12 AM PDT            3.64            617         -              Normal
  04/20/2026 01 AM PDT            3.70            644         +              Normal
  04/20/2026 02 AM PDT            3.69            639         -              Normal
  04/20/2026 03 AM PDT            3.66            626         -              Normal
  04/20/2026 04 AM PDT            3.69            639         +              Normal
  04/20/2026 05 AM PDT            3.67            630         -              Normal
  04/20/2026 06 AM PDT            3.67            630         0              Normal
  04/20/2026 07 AM PDT            3.66            626         -              Normal
  04/20/2026 08 AM PDT            3.65            621         -              Normal
  04/20/2026 09 AM PDT            3.66            626         +              Normal
  04/20/2026 10 AM PDT            3.62            608         -              Normal
  04/20/2026 11 AM PDT            3.63            612         +              Normal
  04/20/2026 12 PM PDT            3.61            603         -              Normal
  04/20/2026 01 PM PDT            3.62            608         +              Normal
  04/20/2026 02 PM PDT            3.61            603         -              Normal
  04/20/2026 03 PM PDT            3.58            590         -              Normal
  04/20/2026 04 PM PDT            3.55            577         -              Normal
  04/20/2026 05 PM PDT            3.54            573         -              Normal
  04/20/2026 06 PM PDT            3.54            573         0              Normal
  04/20/2026 07 PM PDT            3.52            564         -              Normal
  04/20/2026 08 PM PDT            3.52            564         0              Normal
  04/20/2026 09 PM PDT            3.52            564         0              Normal
  04/20/2026 10 PM PDT            3.51            560         -              Normal
  04/20/2026 11 PM PDT            3.57            586         +              Normal
  04/21/2026 12 AM PDT            3.57            586         0              Normal
  04/21/2026 01 AM PDT            3.54            573         -              Normal
  04/21/2026 02 AM PDT            3.58            590         +              Normal
  04/21/2026 03 AM PDT            3.57            586         -              Normal
  04/21/2026 04 AM PDT            3.56            581         -              Normal
  04/21/2026 05 AM PDT            3.58            590         +              Normal
  04/21/2026 06 AM PDT            3.59            594         +              Normal
  04/21/2026 07 AM PDT            3.60            599         +              Normal
  04/21/2026 08 AM PDT            3.61            603         +              Normal
  04/21/2026 09 AM PDT            3.55            577         -              Normal
  04/21/2026 10 AM PDT            3.56            581         +              Normal
  04/21/2026 11 AM PDT            3.55            577         -              Normal
  04/21/2026 12 PM PDT            3.54            573         -              Normal
  04/21/2026 01 PM PDT            3.53            568         -              Normal
#
# FORECAST
#
# Date & Time  (Local)    Stage (Feet)     Flow (cfs)     Trend     Forecast Status
# ---------------------------------------------------------------------------------
  04/21/2026 02 PM PDT            3.52            564                        Normal
  04/21/2026 03 PM PDT            3.52            564         0              Normal
  04/21/2026 04 PM PDT            3.52            564         0              Normal
  04/21/2026 05 PM PDT            3.52            564         0              Normal
  04/21/2026 06 PM PDT            3.53            568         +              Normal
  04/21/2026 07 PM PDT            3.54            573         +              Normal
  04/21/2026 08 PM PDT            3.55            577         +              Normal
  04/21/2026 09 PM PDT            3.55            577         0              Normal
  04/21/2026 10 PM PDT            3.56            581         +              Normal
  04/21/2026 11 PM PDT            3.56            581         0              Normal
  04/22/2026 12 AM PDT            3.54            573         -              Normal
  04/22/2026 01 AM PDT            3.53            568         -              Normal
  04/22/2026 02 AM PDT            3.51            560         -              Normal
  04/22/2026 03 AM PDT            3.49            551         -              Normal
  04/22/2026 04 AM PDT            3.47            543         -              Normal
  04/22/2026 05 AM PDT            3.45            535         -              Normal
  04/22/2026 06 AM PDT            3.43            526         -              Normal
  04/22/2026 07 AM PDT            3.41            518         -              Normal
  04/22/2026 08 AM PDT            3.39            510         -              Normal
  04/22/2026 09 AM PDT            3.37            502         -              Normal
  04/22/2026 10 AM PDT            3.35            494         -              Normal
  04/22/2026 11 AM PDT            3.33            486         -              Normal
  04/22/2026 12 PM PDT            3.32            482         -              Normal
  04/22/2026 01 PM PDT            3.31            478         -              Normal
  04/22/2026 02 PM PDT            3.30            474         -              Normal
  04/22/2026 03 PM PDT            3.29            471         -              Normal
  04/22/2026 04 PM PDT            3.28            467         -              Normal
  04/22/2026 05 PM PDT            3.28            467         0              Normal
  04/22/2026 06 PM PDT            3.28            467         0              Normal
  04/22/2026 07 PM PDT            3.29            471         +              Normal
  04/22/2026 08 PM PDT            3.29            471         0              Normal
  04/22/2026 09 PM PDT            3.30            474         +              Normal
  04/22/2026 10 PM PDT            3.31            478         +              Normal
  04/22/2026 11 PM PDT            3.32            482         +              Normal
  04/23/2026 12 AM PDT            3.32            482         0              Normal
  04/23/2026 01 AM PDT            3.32            482         0              Normal
  04/23/2026 02 AM PDT            3.32            482         0              Normal
  04/23/2026 03 AM PDT            3.31            478         -              Normal
  04/23/2026 04 AM PDT            3.31            478         0              Normal
  04/23/2026 05 AM PDT            3.30            474         -              Normal
  04/23/2026 06 AM PDT            3.29            471         -              Normal
  04/23/2026 07 AM PDT            3.28            467         -              Normal
  04/23/2026 08 AM PDT            3.27            463         -              Normal
  04/23/2026 09 AM PDT            3.25            455         -              Normal
  04/23/2026 10 AM PDT            3.23            448         -              Normal
  04/23/2026 11 AM PDT            3.22            444         -              Normal
  04/23/2026 12 PM PDT            3.20            437         -              Normal
  04/23/2026 01 PM PDT            3.19            433         -              Normal
  04/23/2026 02 PM PDT            3.19            433         0              Normal
  04/23/2026 03 PM PDT            3.19            433         0              Normal
  04/23/2026 04 PM PDT            3.19            433         0              Normal
  04/23/2026 05 PM PDT            3.21            440         +              Normal
  04/23/2026 06 PM PDT            3.24            451         +              Normal
  04/23/2026 07 PM PDT            3.29            471         +              Normal
  04/23/2026 08 PM PDT            3.41            518         +              Normal
  04/23/2026 09 PM PDT            3.48            547         +              Normal
  04/23/2026 10 PM PDT            3.55            577         +              Normal
  04/23/2026 11 PM PDT            3.60            599         +              Normal
  04/24/2026 12 AM PDT            3.63            612         +              Normal
  04/24/2026 01 AM PDT            3.66            626         +              Normal
  04/24/2026 02 AM PDT            3.68            635         +              Normal
  04/24/2026 03 AM PDT            3.70            644         +              Normal
  04/24/2026 04 AM PDT            3.72            653         +              Normal
  04/24/2026 05 AM PDT            3.73            658         +              Normal
  04/24/2026 06 AM PDT            3.71            649         -              Normal
  04/24/2026 07 AM PDT            3.69            639         -              Normal
  04/24/2026 08 AM PDT            3.67            630         -              Normal
  04/24/2026 09 AM PDT            3.65            621         -              Normal
  04/24/2026 10 AM PDT            3.62            608         -              Normal
  04/24/2026 11 AM PDT            3.60            599         -              Normal
  04/24/2026 12 PM PDT            3.58            590         -              Normal
  04/24/2026 01 PM PDT            3.58            590         0              Normal
  04/24/2026 02 PM PDT            3.58            590         0              Normal
  04/24/2026 03 PM PDT            3.58            590         0              Normal
  04/24/2026 04 PM PDT            3.59            594         +              Normal
  04/24/2026 05 PM PDT            3.61            603         +              Normal
  04/24/2026 06 PM PDT            3.66            626         +              Normal
  04/24/2026 07 PM PDT            3.70            644         +              Normal
  04/24/2026 08 PM PDT            3.76            672         +              Normal
  04/24/2026 09 PM PDT            3.81            696         +              Normal
  04/24/2026 10 PM PDT            3.86            720         +              Normal
  04/24/2026 11 PM PDT            3.90            740         +              Normal
  04/25/2026 12 AM PDT            3.91            745         +              Normal
  04/25/2026 01 AM PDT            3.92            750         +              Normal
  04/25/2026 02 AM PDT            3.93            755         +              Normal
  04/25/2026 03 AM PDT            3.93            755         0              Normal
  04/25/2026 04 AM PDT            3.93            755         0              Normal
  04/25/2026 05 AM PDT            3.93            755         0              Normal
  04/25/2026 06 AM PDT            3.91            745         -              Normal
  04/25/2026 07 AM PDT            3.88            730         -              Normal
  04/25/2026 08 AM PDT            3.85            715         -              Normal
  04/25/2026 09 AM PDT            3.83            705         -              Normal
  04/25/2026 10 AM PDT            3.79            686         -              Normal
  04/25/2026 11 AM PDT            3.78            681         -              Normal
  04/25/2026 12 PM PDT            3.76            672         -              Normal
  04/25/2026 01 PM PDT            3.75            667         -              Normal
  04/25/2026 02 PM PDT            3.75            667         0              Normal
  04/25/2026 03 PM PDT            3.75            667         0              Normal
  04/25/2026 04 PM PDT            3.76            672         +              Normal
  04/25/2026 05 PM PDT            3.78            681         +              Normal
  04/25/2026 06 PM PDT            3.82            700         +              Normal
  04/25/2026 07 PM PDT            3.86            720         +              Normal
  04/25/2026 08 PM PDT            3.90            740         +              Normal
  04/25/2026 09 PM PDT            3.93            755         +              Normal
  04/25/2026 10 PM PDT            3.97            775         +              Normal
  04/25/2026 11 PM PDT            3.99            785         +              Normal
  04/26/2026 12 AM PDT            3.99            785         0              Normal
  04/26/2026 01 AM PDT            3.98            780         -              Normal
  04/26/2026 02 AM PDT            3.97            775         -              Normal
  04/26/2026 03 AM PDT            3.96            770         -              Normal
  04/26/2026 04 AM PDT            3.95            765         -              Normal
  04/26/2026 05 AM PDT            3.94            760         -              Normal
#
# NOTE 1: Stages are rounded to the nearest hundredth (.01) of a foot.
# NOTE 2: Flows are rounded to the nearest (1) cfs.
# NOTE 3: Trends are determined using hourly change in unrounded stage and flow.
# NOTE 4: Maximum Values are determined using unrounded stage and flow.