Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
638 PM EDT Fri Aug 14 2020
Valid 12Z Tue Aug 18 2020 - 12Z Sat Aug 22 2020
...Guidance Evaluation and Preferences...
Overall, model/ensemble guidance continued to show near to above
average consensus through the extended forecast period. A blend of
the 12Z ECMWF/GFS was used heavily as a forecast starting point
initially on days 4-5 (Tue-Wed). A gradual trend toward increased
weight placed on ensemble means (ECENS/GEFS) was shown through
time after Wed, with majority ensembles in the blend during days
7-8 (Fri-Sat). Overall, guidance is consistent in showing a fairly
amplified pattern continuing, with an upper trough persistent
across the Gulf of Alaska, and ridging expected to build across
the Bering Sea next week.
...Weather Highlights/Threats...
A low pressure system is forecast to cross the Alaska Peninsula on
Tue, moving into the Gulf of Alaska through the middle/end of next
week. This system will keep precipitation a distinct possibility
across southern mainland Alaska as well as the Panhandle. Farther
north, a weakening frontal boundary across the Interior should
bring scattered showers by next Tue-Wed. By later next week, as
upper ridging builds across the Bering Sea and western mainland
Alaska, drier conditions should prevail across much of mainland,
with only the Panhandle/Southeast Alaska remaining wet. In
general, this pattern should favor temperatures several degrees
above average across much of the state. The North Slope will see
decreasing temperatures north of the weakening frontal boundary
next week, with high temperatures expected to drop to a few
degrees below average.
Ryan
Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
Hazards: No significant hazards are expected over Alaska during
this forecast period.
WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can also be
found at:
https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html