AGAK78 PACR 182300
HMDACR

HYDROMETEOROLOGICAL DISCUSSION
NWS ALASKA-PACIFIC RIVER FORECAST CENTER ANCHORAGE AK 
300 PM ADT MON AUG 18 2003

...FLOOD POTENTIAL... 
THE FLOOD WARNING FOR THE YENTNA RIVER AND ITS TRIBUTARIES WAS CANCELLED
MONDAY MORNING.  WATER LEVELS CRESTED SUNDAY EVENING AND HAVE DROPPED BELOW
FLOOD STAGE.  ADDITIONAL RAIN IS FORECAST FOR TUESDAY HOWEVER AMOUNTS ARE
NOT EXPECTED TO CAUSE SIGNIFICANT RISES ON THE YENTNA.  WHILE RIVER LEVELS
WILL REMAIN VERY HIGH THROUGH MIDWEEK THEY ARE NOT EXPECTED TO REACH FLOOD
STAGE.  

THE POTENTIAL FOR LARGE SCALE FLOODING IS CURRENTLY LOW ACROSS THE
REMAINDER OF THE STATE OF ALASKA.

...HYDROMETEOROLOGICAL CONDITIONS...................................
FINALLY THE SOUTHERN MAINLAND SHOWED SIGNS OF DRYING OUT.  CONSIDERABLE
RAINFALL ONLY FELL ACROSS THE EXTREME SOUTHERN PANHANDLE WHERE SHELTER COVE
RECEIVED 2.32" AND ANNETTE RECEIVED 2.17" FOR THE 24 HOUR PERIOD ENDING AT
4AM.  THE PESKY SURFACE LOW OVER THE COOK INLET REGION RUNG ITSELF OUT OF
AVAILABLE MOISTURE.  SCATTERED SHOWERS IN THE SUSITNA VALLEY BROUGHT
BETWEEN 0.25 AND 0.50 INCHES OF RAIN.  

ON MONDAY SURFACE HIGH PRESSURE BUILT OVER THE GULF OF ALASKA AND EXTENDED
INLAND OVER THE KENAI PENINSULA.  CLEARING SKIES WERE WELCOME TO
SOUTHCENTRAL ALASKA AFTER ONE WEEK OF PERSISTENT CLOUDS AND RAINFALL.  THE
SYSTEM THAT BROUGHT OVER 2" OF RAIN TO SOME SOUTHERN PANHANDLE LOCATIONS
HAS EXITED NORTHEAST INTO NORTHERN BRITISH COLUMBIA.  SOME LIGHT WRAPAROUND
MOISTURE BROUGHT SOME LIGHT RAIN TO THE FORTYMILE COUNTRY AND ALONG THE
NORTH SLOPES OF THE WRANGELLS.          

THE UPPER LOW OVER THE BERING SEA THAT HAS BEEN FORCING THE PERSISTENT
WEATHER PATTERN THIS PAST WEEK FINALLY BEGINS TO DRIFT SOUTHEASTWARD.  IT
IS FORECAST TO BE POSITIONED BETWEEN THE PRIBILOFS AND BRISTOL BAY BY
TUESDAY MORNING AND OVER THE NORTHERN GULF OF ALASKA BY WEDNESDAY EVENING. 
A DEVELOPING WAVE SOUTH OF THE ALEUTIANS WILL EVENTUALLY FORM A SURFACE LOW
AND GET ENTRAINED INTO THE UPPER TROUGH AS IT DIGS SOUTHEASTWARD.  ANOTHER
ROUND OF RAIN IS EXPECTED TO HIT SOUTHCENTRAL ALASKA MONDAY NIGHT INTO
TUESDAY.  AFTER PASSAGE OF THIS TROUGH AND ASSOCIATED FRONT A MODERATE
UPPER RIDGE BUILDS ALONG 180.  THIS RIDGE SHOULD BRING DRIER NORTHWESTERLY
FLOW ALOFT FOR SOUTHCENTRAL ALASKA. 

FREEZING LEVELS LOWERED SLIGHTLY FROM EARLY SUNDAY TO EARLY MONDAY. 
FREEZING LEVELS SLOPED FROM 4000 FT ALONG THE WEST COAST TO 6000 FT ALONG A
PRUDHOE BAY-FAIRBANKS-CORDOVA LINE.  THE SOUTHEAST PANHANDLE HAD FREEZING
LEVELS BETWEEN 6000 AND 8000 FT. 

...HYDROLOGIC CONDITIONS...
THE MAIN AREA OF HYDROLOGIC CONCERN IS IN THE WESTERN SUSITNA VALLEY. 
ALTHOUGH THE FLOOD WARNING HAS BEEN CANCELLED RIVER LEVELS WILL REMAIN VERY
HIGH THROUGH MIDWEEK. 

WATER LEVELS ON THE YUKON RIVER AT EAGLE ARE HOLDING STEADY BUT ARE MUCH
BELOW AVERAGE LEVELS.  THE YUKON AT THE BRIDGE IS SLOWLY RISING WITH BELOW
NORMAL WATER LEVELS.  AT PILOT STATION YUKON RIVER LEVELS ARE ABOVE
NORMAL AND RECEDING.  

THE KOBUK AND KOYUKUK RIVERS ARE RUNNING HIGH DUE TO RECENT MODERATE
RAINFALL LAST WEEK ALONG THE SOUTHERN SLOPES OF THE CENTRAL AND WESTERN
BROOKS RANGE.

TANANA RIVER LEVELS AT FAIRBANKS AND NENANA ARE ABOVE NORMAL BUT SLOWLY
RECEDING.

THE KUSKOKWIM RIVER CRESTED SATURDAY AT MCGRATH AND SUNDAY AT LISKYS
CROSSING.  THE LOWER KUSKOKWIM CONTINUES TO RISE.  

THE KENAI RIVER AT COOPER LANDING CRESTED ON SUNDAY AND IT SHOULD CREST
TODAY AT SOLDOTNA.  RIVER LEVELS ARE CURRENTLY RUNNING SLIGHTLY ABOVE
NORMAL.

LARGER RIVERS IN SOUTHEAST ALASKA CRESTED ON SUNDAY AFTER A WEEK OF RISING
LEVELS FROM RAINFALL AND GLACIAL RUNOFF.  THESE RIVERS ARE NOW RECEDING
SHARPLY YET ARE STILL ABOVE NORMAL.

.....................................................................

IF YOU HAVE ANY QUESTIONS OR COMMENTS PLEASE CALL THE RIVER FORECAST 
CENTER AT 907-266-5160 OR VISIT HTTP://APRFC.ARH.NOAA.GOV/.  THE
HYDROMETEOROLOGICAL DISCUSSION WILL BE ISSUED DAILY AT 3 PM UNTIL 
FREEZE-UP IN THE FALL. 

$$
BCB