Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
333 PM EDT Thu May 09 2019
Valid 12Z Mon May 13 2019 - 12Z Fri May 17 2019
Latest guidance still generally holds a blocky flow pattern into
next week as highlighted aloft by a closed/high amplitude and
unsettling/modest precipitation focusing Bering Sea and
Aleutians/Alaskan Peninsula to Gulf of Alaska trough. A resultant
and high amplitude upper ridge extends downstream from the
northeast Pacific and Alaskan Panhandle to a warmed Alaskan
Interior. Emerging flow to the south of the state days 5-8
portends some pattern transition as increasing energy infuses from
the north-central Pacific to the Gulf of Alaska to favor offshore
and more progressive offshore storm developments with inherent
maritime risks.
Model and ensemble forecasts cluster better now day 4/Monday into
Day 5/Tuesday and a composite solution offers reasonable
continuity. Guidance solutions then diverge quickly through later
next week. Accordingly and in coordination with the local Alaskan
weather forecast offices, the WPC Alaskan medium range product
suite day 6-8 was primarily derived from a blend of compatable
guidance from the 12 UTC GEFS mean and 00 UTC ECMWF ensemble mean,
along with small model and National Blend of Model inputs to
provide slightly better detail.
Schichtel
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
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