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SRAK48 PACR 212300
ACRRVAAK
AKZALL-222200-
HYDROLOGIC OUTLOOK
NWS ALASKA PACIFIC RIVER FORECAST CENTER ANCHORAGE AK
300 PM ADT THU MAY 23 2013
...SPRING BREAKUP OUTLOOK FOR ALASKA... THE SPRING BREAKUP FLOOD
POTENTIAL THROUGHOUT ALASKA IS CURRENTLY RATED AS MODERATE FOR MOST OF
THE STATE. THIS FORECAST IS BASED ON OBSERVED SNOWPACK...ICE THICKNESS
REPORTS AND LONG RANGE TEMPERATURE FORECASTS. MODERATE TO MAJOR
FLOODING HAS AFFECTED THE YUKON COMMUNITIES OF EAGLE AND CIRCLE.
CURRENTLY FLOOD WATCHES ARE IN EFFECT ON THE YUKON RIVER FROM BEAVER
TO TANANA.
SHORT TERM FLOOD OUTLOOK- INCREASED SNOWMELT DUE TO WARMING
TEMPERATURES ACROSS INTERIOR ALASKA WILL CAUSE RIVER AND STREAMS TO
RISE STEADILY INTO NEXT WEEK. THIS WILL INCREASE THE FLOOD THREAT ON
THE LOWER KUSKOKWIM RIVER AND LOWER YUKON RIVER NEXT WEEK. IN ADDITION
SIGNIFICANT WATER LEVEL INCREASES WILL OCCUR ON RIVERS AND STREAMS IN
SOUTHCENTRAL ALASKA DURING THE NEXT 10 DAYS SOME MINOR FLOODING IS
POSSIBLE.
ICE - MAY 1ST ICE THICKNESS MEASUREMENTS ARE AVAILABLE FOR A LIMITED
NUMBER OF SITES IN ALASKA. THEY INDICATE THAT ICE THICKNESS WAS
GENERALLY BETWEEN 100 AND 150 PERCENT OF NORMAL. ICE CONTINUES TO
SLOWLY DETERIORATE OVER MUCH OF ALASKA.
SNOW - AN ANALYSIS OF THE MAY 1 SNOWPACK BY THE NATURAL RESOURCES
CONSERVATION SERVICE (NRCS) INDICATED A MUCH ABOVE NORMAL SNOWPACK
OVER MUCH OF THE STATE. SIGNIFICANT APRIL SNOW ACTUALLY INCREASED THE
SNOWPACK ACROSS THE STATE. THIS REMAINING SNOWPACK COULD BE ENOUGH TO
PRODUCE SIGNIFICANT SNOWMELT RUNOFF PEAKS AND POTENTIAL FLOODING IF
SUBJECTED TO A RAPID WARMING PATTERN. THIS SNOWMELT FLOODING COULD
OCCUR IN AREAS WHERE THE RIVER ICE HAS ALREADY CLEARED OUT OR HAS
BECOME ROTTEN IN PLACE IF THE WARMING IS SUDDEN AND ABOVE NORMAL.
FOR MORE DETAILS ON THE SNOWPACK.. PLEASE REFER TO THE VARIOUS SNOW
GRAPH OPTIONS AT THE APRFC WEB SITE AT HTTP://APRFC.ARH.NOAA.GOV OR
ON THE NRCS WEB SITE AT
HTTP://WWW.AK.NRCS.USDA.GOV/SNOW/DATA/CURRENT.HTML
WEATHER - WARMER THAN NORMAL TEMPERATURES ARE EXPECTED ACROSS MUCH OF
THE STATE FOR THE NEXT 10 DAYS. INCREASED SNOWMELT WILL OCCUR ALONG
WITH SIGNFICANT DECAY OF ICE REMAINING IN THE YUKON AND KUSKOKWIM
RIVERS AS WELL AS RIVER ACROSS THE NORTH SLOPE AND NORTHWEST PART OF
THE STATE.
AREAS OF SOUTHCENTRAL ALASKA THAT RECEIVED SIGNIFICANT RAINFALL LAST
FALL LIKELY HAVE HIGHER THAN NORMAL GROUNDWATER LEVELS. THESE AREAS
ARE MORE SUSCEPTIBLE TO MINOR FLOODING AND DRAINAGE ISSUES IN THE
EVENT OF A RAPID WARM UP.
FOR MORE INFORMATION ON THE OUTLOOKS FOR THIS SPRING PLEASE REFER TO
THE CLIMATE PREDICTION CENTER WEB SITE AT
HTTP://WWW.CPC.NCEP.NOAA.GOV/INDEX.PHP
RECENT BREAKUP ACTIVITY:
*********************************************************************
*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 BREAK UP. PLEASE USE CAUTION AT*
*ALL TIMES WHEN ATTEMPTING TO NAVIGATE RIVERS. *
*********************************************************************
SUSITNA RIVER... THE ICE IS OUT ON THE YENTNA AND SKWENTA RIVERS. ICE
RUNS AND SOME IN PLACE ICE EXISTS IN THE SUSITNA RIVER NEAR ITS MOUTH
AND ABOVE CURRY. WATER LEVELS ARE REPORTED TO BE LOW.
COPPER RIVER... THE GAKONA AND GULKANA RIVERS ARE MOSTLY OPEN NEAR
THEIR CONFLUENCE WITH THE COPPER RIVER. THE COPPER RIVER IS REPORTED
TO HAVE SOME OPEN LEADS HOWEVER A LOT OF ICE STILL REMAINS IN THE
CHANNEL ABOVE COPPER CENTER AND ICE CONDITIONS ON THE COPPER RIVERARE
UNKNOWN DOWNRIVER FROM CHITINA.
TANANA RIVER.. THE RIVER IS MOSTLY OPEN FROM NORTHWAY TO OLD MINTO.
THE ICE IS SHIFTING IN VICINITY OF MANLEY.
KUSKOKWIM RIVER... THE TRIPOD AT MCGRATH TRIPPED LAST NIGHT. DOWN
RIVER FROM MCGRATH TO SLEETMUTE THE ICE IS SHIFTING IN PLACE.
DOWNRIVER FROM SLEETMUTE TO CROOKED CREEK THE RIVER IS MOSTLY OPEN.
TEN MILES DOWN RIVER FROM NAPAIMUTE THE ICE IS JAMMED AND WATER LEVELS
ARE REPORTED TO BE HIGH IN NAPAIMUTE. THE ICE IS LIFTED AND ROTEN IN
THE ANIAK AREA AND WATER IS REPORTED TO COMING UP SLOWLY.
KOYUKUK RIVER... ICE AT BETTLES IS ROTTING WITH LOTS OF OVERFLOW AND
SOME SHIFTING BREAKUP SHOULD OCCUR IN THE NEXT DAY OR TWO.
YUKON RIVER... DAWSON WENT OUT LATE WEDNESDAY THE 15TH. THE ICE MOVED
IN EAGLE AFTER MIDNIGHT AND INTO THE EARLY MORNING OF MAY 17TH BEFORE
JAMMING AND CAUSING MODERATE FLOODING IN EAGLE. THE ICE JAM RELEASED
AND A SURGE OF WATER CAUSED MAJOR FLOODING IN CIRCLE SUNDAY MAY 19TH.
THE ICE JAM THAT FORMED 12 MILES UPRIVER FROM FORT YUKON REMAINS IN
PLACE HOWEVER WATER HAS CUT A CHANNEL ALONG THE RIVER BANK ALLOWING
FOR A SLOW RELEASE OF WATER DOWN PAST FORT YUKON. THE BREAKUP FRONT IS
CURRENTLY LOCATED APPROXIMATELY 20 MILES DOWNRIVER FROM BEAVER WHERE
THERE ARE CURRENT FLOOD WATCHES FOR BEAVER... STEVENS VILLAGE...
RAMPART AND TANANA.
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. SNOWMELT FLOODING COULD OCCUR SEPARATELY
FROM ICE JAMS FLOODS OR IN CONJUNCTION WITH THEM
* AVERAGE BREAKUP DATES ARE FOR THE PERIOD 1970 THROUGH 2012 AND ARE
CALCULATED FOR LOCATIONS WITH AT LEAST 5 YEARS OF DATA.
** INDICATES ACTUAL BREAKUP DATE
---------------------------------------------------------------------
SNOWMELT FLOOD AVERAGE NO. OF FORECAST
RIVER - REACH RUNOFF POTENTIAL BREAKUP YEARS BREAKUP
VOLUME DATE * RECORD DATE
------------- ---------- --------- ------- ------ --------
SOUTHEAST PANHANDLE ABOVE
KENAI RIVER ABOVE
ANCHOR RIVER ABOVE 04/16 10
MATANUSKA RIVER ABOVE 04/30 8
SUSITNA RIVER ABOVE
GOLD CREEK LOW-MOD 05/03 9
SUNSHINE LOW-MOD 05/02 28 5/19-5/21
YENTNA RIVER AVERAGE
LAKE CREEK LOW-MOD 05/01 22 5/14**
SKWENTNA RIVER AVERAGE
SKWENTNA LOW-MOD 05/03 19 5/13**
COPPER RIVER BASIN AVERAGE
GAKONA RVR @ HWY LOW 05/02 25 5/19-5/21
GULKANA RVR @ HWY LOW 05/01 29 5/19-5/21
CHENA RIVER ABOVE
CHENA LAKES PROJECT LOW
FAIRBANKS LOW 04/28 26 5/15**
TANANA RIVER ABOVE
NORTHWAY LOW 04/21 31 5/08**
SALCHA MODERATE 5/15**
FAIRBANKS LOW 04/29 14 5/16**
NENANA LOW-MOD 05/04 39 5/21**
MANLEY LOW-MOD 05/01 23 5/23-5/24
KUSKOKWIM RIVER AVERAGE
NIKOLAI LOW 04/24 30 5/09**
MCGRATH LOW 05/07 39 5/22**
STONY RIVER LOW 05/05 25 5/20**
SLEETMUTE LOW 05/05 24 5/20**
RED DEVIL MODERATE 05/06 27 5/21**
CROOKED CREEK MODERATE 05/07 27 5/22
ANIAK MODERATE 05/08 34 5/23-5/25
KALSKAG LOW-MOD 05/08 24 5/24-5/26
TULUKSAK LOW-MOD 05/10 21 5/25-5/28
AKIAK LOW-MOD 05/10 27 5/25-5/28
KWETHLUK MODERATE
BETHEL LOW-MOD 05/12 42 5/26-5/29
NAPAKIAK LOW-MOD 05/13 19 5/26-5/29
YUKON RIVER (UPPER) ABOVE
DAWSON, YT 05/06 43 5/15**
EAGLE MODERATE 05/05 35 5/17**
CIRCLE MODERATE 05/09 31 5/19**
FORT YUKON MODERATE 05/10 30 5/21**
BEAVER MODERATE 05/11 18 5/22**
STEVENS VILLAGE MODERATE 05/12 18 5/23-5/25
RAMPART MODERATE 05/12 18 5/24-5/26
YUKON RIVER (MIDDLE) ABOVE
TANANA MODERATE 05/10 28 5/24-5/27
RUBY LOW 05/11 29 5/25-5/28
GALENA MODERATE 05/13 29 5/25-5/29
KOYUKUK MODERATE
NULATO MODERATE 05/12 17 5/25-5/29
KALTAG LOW 05/14 37 5/26-5/30
ANVIK LOW 05/16 26 5/27-5/30
YUKON RIVER (LOWER) ABOVE
HOLY CROSS LOW 05/16 26 5/27-5/30
RUSSIAN MISSION LOW 05/15 28 5/27-5/31
MARSHALL MODERATE 05/15 22 5/27-5/31
PILOT STATION LOW 05/17 16 5/28-6/01
MOUNTAIN VILLAGE LOW 05/19 26 5/28-6/02
ALAKANUK/EMMONAK MODERATE 05/23 28 5/29-6/03
KOYUKUK RIVER AVERAGE
BETTLES LOW 05/09 31 5/24-5/26
ALLAKAKET LOW 05/10 26 5/25-5/30
HUGHES MODERATE 05/10 32 5/25-5/31
SEWARD PENINSULA BELOW
BUCKLAND RIVER BELOW
BUCKLAND MODERATE 05/18 23 5/26-5/31
KOBUK RIVER BELOW
KOBUK MODERATE 05/16 33 5/25-5/30
SHUNGNAK LOW 05/18 23 5/26-5/31
AMBLER LOW 05/18 30 5/26-5/31
NOATAK RIVER BELOW
NOATAK LOW 05/20 18 5/28-6/02
ROOKS RANGE - NORTH AVERAGE
COLVILLE @ UMIAT LOW 05/24 13 6/01-6/06
COLVILLE @ COLVILLE LOW-MOD 06/01 16 6/07-6/11
FOR MORE DETAIL AND TO SEE A FLOOD POTENTIAL MAP REFER TO OUR WEB
SITE AT HTTP://APRFC.ARH.NOAA.GOV.
THE NEXT SPRING BREAKUP OUTLOOK IS SCHEDULED AT 2 PM FRIDAY
MAY 24.
$$
DPS
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