325  
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  
 
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