Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
348 PM EDT Fri Jul 26 2019
Valid 12Z Tue Jul 30 2019 - 12Z Sat Aug 03 2019
The overall flow pattern over Alaska should be fairly progressive
during the medium range period. This features an upper level low
moving into northwest mainland Alaska before lifting north into
the Arctic, which should push a cold front into western Alaska
before weakening by the end of next week. Meanwhile, several
shortwaves/fronts should push from the Bering Sea to the Gulf,
with a potentially stronger system moving into the Bering Sea by
next weekend. In general, deterministic solutions showed
relatively good consensus for days 4-5 (Tues-Wed) and so a
majority blend of the ECMWF/GFS/CMC as used as a starting point
for that time. After this time, solutions begin to diverge with
respect to both timing and details of individual systems and so
contributions from the ensemble means was quickly increased after
day 5. Did continue slight contributions from the ECMWF through
day 8 due to its better agreement with the ensemble means through
the period and especially with maintaining weaker ridging across
the western coast of Alaska while the latest GFS runs are
noticeably stronger moving into late next week. This approach
agrees well with yesterday's forecast as well as with continuity
downstream across the CONUS. This pattern will support scattered
showers across much of the state as shortwave energy passes over
Alaska and a more amplified trough begins to take shape across the
Bering Sea late next week.
Santorelli
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