Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
345 PM EDT Wed Sep 04 2019
Valid 12Z Sun Sep 08 2019 - 12Z Thu Sep 12 2019
...Weather/Hazards Highlights...
An active weather pattern for Alaska and adjoining waters next
week. The lifting of a weekend northern Bering Sea low through the
Bering Strait into the Arctic Monday will produce modest
precipitation and unsettled weather.
A lead southern stream upper closed low/trough will meanwhile exit
through the southeast panhandle to produce lingering weekend
unsettled weather and precipitation. Dynamic upstream system
energy and deepened surface low/system will track across the
Aleutians/Southern Bering Sea and Alaskan Peninsula Sunday-Tuesday
to then emerge over the Gulf of Alaska along with a heightening
threat of wrapping heavy weather and seas. A deep low is then
expected to track eastward from coastal Asia into the Bering Sea
with roots from typhoons Lingling and Fourteen-W. This pedigree
suggests a likely significant maritime hazard that would be slated
to effect the Aleutians then mainland Alaska near the end of this
forecast period that needs to be closely monitored.
...Guidance and Predictabililty Assessment...
Recent models and ensembles show ample smaller scale/embedded
system variance but overall reasonable compatability with the
larger scale flow evolution. Accordingly, the WPC Alaskan medium
range product suite was primarily derived from a composite blend
of the 12 UTC GFS/GEFS and ECMWF/ECMWF ensemble mean.
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