River Summary
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8
000
SRAK48 PACR 222307
RVAAK
AKZALL-172300-

ALASKA SPRING BREAKUP SUMMARY
NWS ALASKA PACIFIC RIVER FORECAST CENTER ANCHORAGE AK
330 PM ADT MAY 22 2017

...SPRING BREAKUP SUMMARY FOR ALASKA....

FLOOD WARNING/WATCHES:
None

Alaska Breakup Summary Notable Events from Past 24 hours -

Breakup is complete on the Yukon with only isolated chunk ice moving
at various locations on the river. Much of the Kobuk river is now open, with
reports of some ice still at the mouth and headwaters.  The Noatak still has ice
at its mouth but this is deteriorating. North Slope rivers are starting to move
with some open water.

Current State wide flood potential -
The flood potential from snowmelt and ice jams throughout most of Alaska this
spring is now rated as low. As a result of slowly rising temperatures and a
lack of snow in parts of the interior, breakup has become thermal rather than
dynamic which means many breakup fronts and low water.

WEATHER -

The heavy rain that has contributed to highwater conditions in some smaller
streams in Southeast Alaska is tapering in the northern Panhandle. Precipitation
may continue to fall in the the southern Panhandle through midweek. The North
Gulf Coast and Southwest Alaska are likely to see precipitation return Tuesday
High temperatures on the North Slope and the Brooks range will
be in the mid 40s. The Climate Prediction Center expects below normal
temperatures over the Southwest mainland and increased propbabilities of
above normal temperatures over the North Slope and the Panhandle, 6 to 10 days
out. For this same period precipitation is likely to be above normal in the
North and western parts of the state and below normal along the Gulf Coast and
over Southeast Alaska.

For weather, ice, and snow conditions, please refer to
http://www.weather.gov/aprfc/FGAK78PACR and for various snow graph options
refer to the APRFC website at http://www.weather.gov/aprfc or the NRCS website
at http://www.nrcs.usda.gov/wps/portal/nrcs/main/ak/snow/

Recent Breakup Activity Across the State:

*********************************************************************
*EVEN THOUGH A PARTICULAR RIVER OR REACH MAY BE DESCRIBED AS MOSTLY *
*OPEN OR OPEN... IT IS STILL POSSIBLE FOR RUNS OF ICE AND DEBRIS TO *
*MOVE THROUGH AS HEADWATERS UPSTREAM BREAKUP.  PLEASE USE CAUTION AT*
*ALL TIMES WHEN ATTEMPTING TO NAVIGATE RIVERS.                      *
*********************************************************************

SUSITNA RIVER...
The Susitna River is open.

SKWENTNA AND YENTNA RIVER..
The Yentna and Skwentna Rivers are open.

TANANA RIVER..
The Tanana river is open to the mouth.

COPPER RIVER...
The Copper River is open from the headwaters to Chitina. Satellite
imagery shows some ice possible in the canyon.

KUSKOKWIM...
The river is open with isolated ice chunks moving downriver.

YUKON RIVER...
The river is open with isolated ice chunks moving downriver.

KOYUKUK RIVER...
The river is mostly open.

KOBUK RIVER...
Kobuk, Shungnak and Ambler all reported Breakup has occurred in those villages.

SAGAVANIRKTOK RIVER...
Breakup has begun in some locations.

THE FOLLOWING TABLE GIVES AN ESTIMATION OF FLOOD POTENTIAL FOR
VARIOUS LOCATIONS AROUND THE STATE AND BASIN RUNOFF VOLUMES.
---------------------------------------------------------------------
SNOWMELT RUNOFF VOLUME...EXPECTED WATER VOLUME FROM SNOWMELT DURING
                         THE MELT SEASON.

FLOOD POTENTIAL...THE LIKELIHOOD OF FLOODING FROM SNOWMELT AND/OR
                  ICE JAMS.  THIS IS INITIALLY CALCULATED BASED ON THE FLOOD
                  FREQUENCY FOR THE 2000 TO 2015 HISTORICAL RECORD AND ADJUSTED
                  TO REFLECT CURRENT CONDITIONS.

*  AVERAGE BREAKUP DATES ARE FOR THE PERIOD 1980 THROUGH 2015 AND ARE
      CALCULATED FOR LOCATIONS WITH AT LEAST 5 YEARS OF DATA.
** ACTUAL BREAKUP DATE FOR THIS YEAR
---------------------------------------------------------------------

                      SNOWMELT   FLOOD      AVERAGE  NO. OF  FORECAST
RIVER - REACH         RUNOFF     POTENTIAL  BREAKUP  YEARS   BREAKUP
                      VOLUME                DATE *    USED    DATE
-------------         ---------- ---------  -------  ------  --------
Southeast Panhandle

Kenai River                                                   Open

Anchor River        Below Average  Low       04/14     11     4/13**

Matanuska River     Below Average            04/30      8     Open

Susitna River       Below Average
  Gold Creek                       Low       05/03      8    04/29**
  Sunshine                         Low       05/03     27    04/29**

Yentna River        Below Average
  Lake Creek                       Low       05/01     25     4/25**

Skwentna River      Below Average
  Skwentna                         Low       04/30     21     4/24**

Copper River Basin  Below Average
  Gakona Rvr @ HWY                 Low       05/01     29     4/28**
  Gulkana Rvr @ HWY                Low       04/29     28     4/28**

Chena River         Above Average
  Chena Lakes Project
  Fairbanks                      Low-Mod     04/26     24     4/29**

Tanana River        Above Average
  Chisana @ Northway               Low       04/26     27     4/25**
  Salcha                         Low-Mod                      4/27**
  Fairbanks                        Low       04/29     18     5/01**
  Nenana                           Low       04/30     37     5/01**
  Manley                           Low       05/04     27     5/07**

Kuskokwim River     Below Average
  Nikolai                          Low       04/23     31     4/23**
  McGrath                        Low-Mod     05/05     37     5/04**
  Stony River                      Low       05/02     29     4/26**
  Sleetmute                      Low-Mod     05/02     28     4/27**
  Red Devil                      Low-Mod     05/05     31     4/28**
  Crooked Creek                  Low-Mod     05/06     31     5/03**
  Aniak                          Low-Mod     05/07     34     5/03**
  Kalskag                          Low       05/07     28     5/04**
  Tuluksak                         Low       05/08     25     5/07**
  Akiak                            Low       05/10     31     5/07**
  Kwethluk                       Low-Mod     05/10      6     5/06**
  Bethel                           Low       05/11     37     5/06**
  Napakiak                         Low       05/12     22     5/08**

Yukon River (Upper)   Average
  Dawson, YT                                 05/04     36     5/03**
  Eagle                         Low-Mod      05/04     36     5/04**
  Circle                          Mod        05/08     33     5/08**
  Fort Yukon                    Low-Mod      05/10     33     5/11**
  Beaver                          Low        05/10     21     5/12**
  Stevens Village               Low-Mod      05/11     20     5/13**
  Rampart                         Low        05/11     22     5/13**

Yukon River (Middle)  Average
  Tanana                          Low        05/08     32     5/10**
  Ruby                            Low        05/09     31     5/09**
  Galena                        Low-Mod      05/11     36     5/11**
  Koyukuk                       Low-Mod      05/09     12     5/11**
  Nulato                        Low-Mod      05/10     21     5/12**
  Kaltag                          Low        05/12     31     5/10**
  Anvik                           Low        05/14     30     5/11**

Yukon River (Lower)   Average
  Holy Cross                      Low        05/15     30     5/06**
  Russian Mission                 Low        05/16     31     5/06**
  Marshall                      Low-Mod      05/15     25     5/10**
  Pilot Station                   Low        05/16     20     5/05**
  Mountain Village                Low        05/19     30     5/11**
  Alakanuk/Emmonak                Mod        05/21     32     5/14**

Koyukuk River         Average
  Bettles                         Low        05/10     35      5/8**
  Allakaket                       Low        05/10     31      5/9**
  Hughes                        Low-Mod      05/11     30      5/9**

Seward Peninsula      Average
  Buckland                        Mod        05/20     26      5/14**

Kobuk River           Average
  Kobuk                         Low-Mod      05/14     33      5/12**
  Shungnak                        Low        05/17     27      5/14**
  Ambler                          Low        05/18     33      5/14**

Noatak River          Average
  Noatak                          Low        05/19     22  05/16-05/22

Brooks Range - North  Average
  Colville @ Umiat                Low        05/25     17  05/22-05/28
  Colville @ Colville           Low-Mod      06/04     19  06/01-06/07

Sagavanirktok River   Average
  Dalton HWY                    Low-Mod      **/**


For more detail and to see a flood potential map refer to our website at
http://www.weather.gov/aprfc/

The next spring breakup summary is scheduled at 4 PM ADT Tuesday May 23 2017

$$
jec




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.