Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
232 PM EDT Mon Apr 22 2019
Valid 12Z Fri Apr 26 2019 - 12Z Tue Apr 30 2019
...Weather/Threats Highlights...
The upcoming weather pattern will not be very active over most of
Alaska for the next week with main storm tracks well south and
west of the state.
Moderate surface low developments over the northern Gulf of Alaska
will support modest periods of precipitation inland into southern
and southeastern Alaska as enhanced over favored coastal terrain.
These lows will be supported by a mean Gulf of Alaska upper closed
low/trough that will tend to weaken over the period.
There will be storm potential well to the west of the state.
Deepened but quite uncertain systems set to lift poleward off
northeast Asia would threaten at least the Bering Sea, with some
energies working northward up to the Arctic and western Alaska on
the western periphery of a building upper ridge downstream around
165W.
...Guidance/Predictability Assessment
The WPC Alaskan medium range product suite was mainly derived from
a composite blend of the well clustered 12 UTC GFS/GEFS and 00 UTC
ECMWF/ECMWF ensembles Day 4/Friday. Forecast spread increases
dramatically this weekend into next week and run to run continuity
in the models has been less than stellar. Accordingly, shifted the
WPC forecast strategy to embrace a blend of the 12 UTC GEFS mean
and compatable 00 UTC ECMWF ensemble mean. This maintains good WPC
continuity, but offers limited detail consistent with a pattern
with below normal predictability.
Schichtel
Bullet points from the WPC Days 3-7 Hazards chart can be found 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