Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
241 PM EDT Sat Oct 06 2018

Valid 12Z Wed Oct 10 2018 - 12Z Sun Oct 14 2018

The amplified pattern will still have its grip over the Alaska
region through Thursday but will finally break down by Friday. 
The upstream ridge over Japan will weaken and shift, allowing for
a more zonal flow west of the Dateline by the weekend. Overall,
models were in agreement with the pattern, but especially late in
the period and through the weekend, details are still needing to
be worked out.

The 06Z GFS/00Z ECMWF have come to an agreement with the timing of
the ex-Kong-Rey. Both show the center of it approaching the
western Aleutian islands by Tuesday night and will move into the
Bering Sea/southwest Alaska by Wednesday morning and will become
absorbed in the mean trough over the Bering Sea. As the pattern
relaxes on Friday, differences in the operational 12Z GFS/00Z
ECMWF become more apparent with the different embedded systems
moving around the mean low. Overall, the 06Z GEFS/00Z ECENS
agreed--and the 00Z CMC matched up better than the 00Z ECMWF, so
used a blend of the ensemble means with some 00Z ECMWF for detail.
 By Day 8, an impressive low will approach the Aleutians--and both
the GEFS and ECENS were close in proximity where they place the
low.  

As the remnants of Kong-Rey approach south central Alaska,
precipitation will increase especially for this region along with
southwest Alaska. On Thursday and into Friday, conditions should
be drier. By the weekend, the wet pattern will come back and areas
from the Aleutians eastward into southeast portions of the region
should expect an increase in precipitation. Temperatures will be
above average due to the strong ridging except for the Panhandle
with the flow mostly out of western Canada. In general, expect
high temperatures to be in the upper 40s to mid 50s throughout the
week.


Reinhart/Fracasso



WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can be found at:

http://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
http://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
http://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html