Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center

 
 

 

Follow the Weather Prediction Center on Facebook Follow the Weather Prediction Center on Twitter
NCEP Quarterly Newsletter
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   QPF
   PQPF
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Air Quality
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/
Warnings

Satellite and Radar Imagery
   Satellite Images
   National Radar
Product Archive
WPC Verification
   QPF
   Medium Range
   Model Diagnostics
   Event Reviews
International Desks
Development and Training
   Development
WPC Overview
   About the WPC
   Staff
   WPC History
   Accomplishments
   Other Sites
   FAQs
Meteorological Calculators
Contact Us
   About Our Site
 
USA.gov is the U.S. Government's official web portal to all federal, state, and local government web resources and services.
 
Alaska Extended Forecast Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1856Z Dec 09, 2014)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
Abbreviations and acronyms used in this product
 
View Alaska Map


ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
156 PM EST TUE DEC 09 2014

VALID 12Z SAT DEC 13 2014 - 12Z WED DEC 17 2014

THE 9/00Z ECENS/GEFS MEANS SUPPORT A HIGH-LATITUDE 'BLOCK' THIS
MEDIUM RANGE PERIOD---WITH INTENSE WESTERLY PACIFIC JET STREAM
STRETCHED OUT FROM END-TO-END ACROSS THE PACIFIC---INVOF 40 NORTH
LATITUDE. THE MEAN UPPER-LEVEL RIDGE OVER MOUNTAINOUS WESTERN
CANADA WILL BE UNABLE TO FULLY ABSORB THE JET-LEVEL ENERGY AND
SERIES OF SHORTWAVES/CYCLONES EMERGING EAST OF 140W LONGITUDE.
THIS ALLOWS FOR A SUBTLE EXPANSION OF THE BROAD CYCLONIC
CIRCULATION OVER ALASKA'S SOUTH COAST AND PANHANDLE---WITH SOME
BRIEF POLEWARD PROGRESSION OF THE CYCLONIC FLOW FROM TIME TO
TIME---WITH THE MORE ORGANIZED SHORTWAVE ENERGY IMPINGING UPON THE
UPPER-LEVEL RIDGE AXIS.

THOUGHT THE DETERMINISTIC 9/00Z GFS/ECMWF WERE BOTH VERY USEFUL IN
DEPICTING THE AREAS WHERE NEW CYCLONES WILL SPAWN---GIVEN THE
THEIR MEANS EQUALLY DISPLAY THE ZONAL NATURE OF THE JET AXIS CORE
(130+ KT AT 200MB). THROUGH DAY 6...THE DEPTH OF INDIVIDUAL
CYCLONES WILL DETERMINE THE EVENTUAL TRAJECTORY AND FORWARD
SPEED---WITH THE USUAL SPREAD AT THOSE TIME STEPS---FELT A BLEND
OF THE MEANS WOULD SUFFICE FOR THIS FORECAST CYCLE.

VOJTESAK