Gale Warning 11, NWS Fairbanks, AK

NORTHERN ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FAIRBANKS AK
251 AM AKST WED JAN 21 2009

.DISCUSSION...
THE MODELS ARE IN GOOD AGREEMENT FOR ABOUT THE FIRST 48 HOURS BUT
CONTINUE TO DIVERGE THURSDAY WITH CONSIDERABLE DIFFERENCES FROM
MODEL TO MODEL AND RUN TO RUN.

AN UPPER RIDGE THAT STRETCHES FROM SOUTHWEST ALASKA TO THE CHUKCHI
SEA WILL CUT OFF BY THUR AFTERNOON IN THE VICINITY OF PABR-PASC. A
1050 MB SURFACE HIGH ALONG THE BEAUFORT SEA COAST WILL SLIDE OFF
INTO THE WESTERN NW TERRITORIES ON THUR. THE COLDEST AIRMASS WILL BE
ACROSS THE EASTERN INTERIOR. AS THE HIGH RETREATS AND THE WIND
PICKS UP ALONG THE ARCTIC COAST IT WILL LEAD TO SOME WIND CHILL
CONCERNS THROUGH TODAY.  THE PRESSURE GRADIENT WILL ALSO TIGHTEN
ACROSS INTERIOR AK AND MAY LEAD TO SOME CONCERNS WITH BLOWING SNOW.
TEMPERATURES LIKELY NOT COLD ENOUGH IN MOST AREAS ACROSS THE
INTERIOR FOR WIND CHILL ADVISORIES.

THE MODELS CONTINUE TO STRUGGLE WITH ENERGY CUTTING UNDERNEATH
THE UPPER HIGH. THE ECMWF CONTINUES TO BE THE MOST AGGRESSIVE AT
CUTTING OFF A LOW ACROSS THE NORTHERN INTERIOR FRI AND LIFTING THE
LOW UP TO THE BEAUFORT SEA SAT. THE UKMET IS FURTHER SOUTH WITH
THE LOW AND CARRIES THE ENERGY TO THE WEST COAST. THE GFS AND GFS
ENSEMBLES EITHER KEEP THE ENERGY IN CANADA OR BRING A WEAKER LOW
MUCH FURTHER SOUTH CLOSER TO THE UKMET. FORECASTER CONFIDENCE
CONTINUES TO REMAIN LOW.

BY EARLY NEXT WEEK THE MAJORITY OF THE MODELS AND ENSEMBLES BUILD A
RIDGE ACROSS THE BERING SEA WITH A DOWNSTREAM TROUGH ACROSS MUCH OF
THE MAINLAND.  DETAILS CONTINUE TO VARY FROM RUN TO RUN...BUT THIS
SET UP WILL HAVE THE POTENTIAL OF BRINGING VERY COLD AIR BACK INTO
NORTHERN AK.  THE OPERATIONAL GFS DEVELOPS A YAKUTAT LOW BY LATE IN
THE WEEK...WITH THE PATTERN EVERY BIT AS COLD AS THE COLD SNAP OF
LATE DECEMBER INTO THE FIRST 11 DAYS OF THE MONTH.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FOR AKZ203-AKZ204.

GALE WARNING FOR PKZ210-PKZ220-PKZ225.

BRISK WIND ADVISORY FOR PKZ200-PKZ215-PKZ220-PKZ225-PKZ230-
PKZ235-PKZ240-PKZ245.
&&

CF JAN 09