Flood Watch 3, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
220 AM AKDT TUE JUN 30 2015

.DISCUSSION...
MODELS INITIALIZED WELL AND VERIFIED WELL AGAINST THE 00Z AND O6Z
ANALYSIS. MODEL SPREAD IN THE NEAR TERM REMAINS LARGE ON THE LOCATION
AND INTENSITY OF THE CENTRAL AND EASTERN INTERIOR RAIN EVENT
WITH NEARLY 200 MILES DIFFERENCE ON ANTICIPATED LOCATION OF
DEFORMATION ZONE TUESDAY NIGHT THROUGH THURSDAY.

THE 00Z GFS AND NAM BOTH SET UP A HEAVY RAIN CORRIDOR ALONG A OLD
CROW TO EAGLE TO DOT LAKE TO PAXSON LINE. LATEST MODEL RUNS
CONTINUE TO INDICATE 1 TO 3 INCHES OF RAIN FALL ALONG AND 50 MILES
EITHER SIDE OF ABOVE MENTIONED LINE BEGINNING LATE TUESDAY NIGHT
AND CONTINUING INTO THURSDAY. THE 00Z ECMWF SETS UP THE HEAVY
RAIN CORRIDOR ALONG A DENALI NATIONAL PARK TO FAIRBANKS TO EAGLE
LINE WHERE 1 TO 2 INCHES OF RAIN IF FORECASTED TO FALL BETWEEN
LATE TUESDAY NIGHT AND THURSDAY.

THE GFS AND NAM BOTH HANDLED THE LAST RAIN EVENT WELL AND
CONSIDERING THE CONTINUED SOUTH AND EAST ADVANCEMENT OF THE SHORT
WAVE ALONG THE NORTHWEST COAST WE FAVORED THE PLACEMENT OF THE
RAIN CORRIDOR OF THE NAM AND GFS OVER THE ECMWF. SEE HEAVY RAIN
PUBLIC INFORMATION STATEMENT FOR ADDITIONAL DETAILS ON HYDRO
CONCERNS OVER THE EASTERN ALASKA RANGE AND SOUTHEASTERN INTERIOR.
WILL NEED TO CLOSELY MONITOR SMALL STREAMS AND RIVERS IN THE
EASTERN ALASKA RANGE FOR RAPID RISES AS WELL AS THE UPPER TANANA
RIVER BASIN...THE SALCHA RIVER BASIN...THE CHENA RIVER BASIN...THE
DELTANA VALLEY...THE FORTYMILE COUNTRY AND ESPECIALLY THE GOOD
PASTER RIVER BASIN FOR RAPID WATER LEVEL RISES.

MODELS IN THE MID TERM AND EXTENDED TERM CONTINUE TO INDICATE A
STRONG RIDGE BUILDING OVER THE WEST COAST AND WESTERN INTERIOR
OVER THE WEEKEND AND OVER THE CENTRAL AND EASTERN INTERIOR NEXT
WEEK. IN GENERAL THE MODELS AGREE ON A HIGH AMPLITUDE AND VERY
WARM RIDGE BUILDING IN OVER ALASKA HOWEVER TODAYS MODEL RUNS
DIFFER IN THE DETAILS ON EXACTLY WHERE OVER ALASKA THE RIDGE
WILL BUILD AND HOW STRONG.

COASTAL HAZARD POTENTIAL DAYS 3 AND 4...NONE

&&

.FIRE WEATHER...
MIN RH VALUES OVER THE SOUTHEAST INTERIOR AND CENTRAL INTERIOR
WILL BE ON THE RISE AHEAD OF UPCOMING RAIN EVENT. EXPECT WETTING
RAINS TO DEVELOP OVER THE FORTYMILE COUNTRY WESTWARD TO JUST EAST
OF FAIRBANKS BY TUESDAY NIGHT AND CONTINUE INTO THURSDAY. GAP
WINDS THROUGH THE ALASKA RANGE WILL APPROACH RED FLAG CRITERIA
HOWEVER RH VALUES ARE NOT EXPECTED TO REACH CRITERIA WITH INCOMING
RAIN. MIN RH VALUES ARE EXPECTED TO DROP INTO THE LOW 30S AND
UPPER 20S NORTH OF THE YUKON RIVER TODAY HOWEVER WIND CRITERIA IS
NOT EXPECTED TO BE MET.

&&

.HYDROLOGY...
CONTINUE TO MONITOR EVOLVING RAIN EVENT OVER THE EASTERN ALASKA
RANGE AND SOUTHEAST INTERIOR. SEE HEAVY RAIN PUBLIC INFORMATION
STATEMENT FOR ADDITIONAL DETAILS ON HYDRO CONCERNS OVER THE
EASTERN ALASKA RANGE AND SOUTHEASTERN INTERIOR. WILL NEED TO
CLOSELY MONITOR SMALL STREAMS AND RIVERS IN THE EASTERN ALASKA
RANGE FOR RAPID RISES AS WELL AS THE UPPER TANANA RIVER
BASIN...THE SALCHA RIVER BASIN...THE CHENA RIVER BASIN...THE
DELTANA VALLEY...THE FORTYMILE COUNTRY AND ESPECIALLY THE GOOD
PASTER RIVER BASIN FOR RAPID WATER LEVEL RISES.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
DENSE SMOKE ADVISORY FOR AKZ221.

SMALL CRAFT ADVISORY FOR PKZ210.
&&

CCC JUN 15