Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
348 PM EDT Sat Aug 31 2019
Valid 12Z Wed Sep 04 2019 - 12Z Sun Sep 08 2019
There remains good guidance signal into mid-later next week for
organized low system development to mainly effect western Alaska
and maritime interests over the central and northern Bering
Sea/Bering Strait. A blend of the quite well clustered and
reasonable 12 UTC GFS and ECMWF was used in this period of above
average forecast confidence.
Upper trough amplification back into the Aleutians and southern
Bering Sea then AKpen/Southwest AK still has support for a pattern
favorable for additional organized low system developments and
widespread heavy weather/rainfall potential mid-later next week
and next weekend along with lead southern stream low lift up into
the Gulf of Alaska. Forecast spread has improved into the day 7-8
timeframe, so a composite blend of the GFS/ECMWF and GEFS/ECMWF
ensembles seems reasonable in a period of above average
predictability.
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
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