Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
104 PM EST Wed Feb 27 2019
Valid 12Z Sun Mar 03 2019 - 12Z Thu Mar 07 2019
...Summary...
It remains the case that a powerful storm track is expected to
hold in place from off eastern Asia northeastward into the Bering
Sea over the next week. A mean trough aloft with embedded closed
lows will continue to bring a series of deep lows into the Bering
Sea that will move through the Aleutians toward western Alaska
whose eastward motions should be limited by an amplified mid-upper
level mean ridge built up through the Interior and North Slope.
...Guidance and Predictability Assessment...
A composite blend of well clustered guidance from the 12 UTC
GFS/GEFS and 00 UTC ECMWF/ECMWF ensemble mean offers a good basis
for the forecast this weekend into Monday, but increasing model
spread suggests a quick transition to the still compatable
ensemble means later Monday into next Thursday/Day 8. This
forecast maintains good continuity with yesterdays WPC forecast
suite.
...Weather Highlights and Hazards...
The next in a series of deep storms will effect the Aleutians and
Bering Sea this weekend and early next week as it gradually lifts
and weakens over the western Bering. Lead effects work to
southwest Alaska/AKpen and western Alaska during this period.
Another deep low tracks to the Aleutians in about a week.
Otherwise, most of the rest of the state will remain mainly
precipitation free under the mean upper ridge. Temperatures will
be above average through the medium range period, with max
anomalies likely across the North Slope into northwestern Alaska.
Temperatures over the Panhandle will be slightly below average due
to northeasterly/easterly flow out of Canada, especially for the
weekend and into next week as the upper high slips northward and
allows a cool push of air to leak southwestward out of the Yukon.
Bullet points from the WPC Days 3-7 Hazards chart:
https://www.wpc.ncep.noaa.gov/threats/threats.php
High significant wave heights/winds effecting coastal western AK,
Mar 4-Mar 5.
High winds across the Aleutians, Mar 3-Mar 4 and Mar 6-Mar 7.
Schichtel
WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can 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