Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
518 PM EST Wed Jan 06 2021
Valid 12Z Sun Jan 10 2021 - 12Z Thu Jan 14 2021
...Major lows offer heavy precipitation and wind/waves threats
from the Gulf of Alaska to Southern and Southeast Alaska...
...Guidance/Uncertainty Assessment and Weather/Hazards
Highlights...
Major lows will spin over the Gulf of Alaska this weekend into
next week. Guidance still offers a well defined signal in support
of strong system development whose enhanced onshore moisture fetch
and circulations are expected to fuel a threat of heavy
precipitation and high winds/waves from the Gulf into southern and
southeast Alaska. A deepened low is slated to enter the western
Gulf from the Aleutians this weekend and energies will interact
with a lead Gulf storm to maintain a very stormy pattern with
multiple/complex lows into next midweek to focus over the northern
Gulf and into southern and southeast Alaska. Given the predicted
intensity of these systems, there will be strong winds and
hazardous marine conditions. The pattern should also increasingly
favor establishment of much above normal temperatures across the
Interior this period.
The WPC Alaskan product suite was derived from a composite of
reasonably well clustered guidance from the 12 UTC
GFS/ECMWF/UKMET/Canadian and the 19 UTC National Blend of Models
(NBM) Sun-Mon before rapid transition to still compatible
GEFS/ECMWF ensemble means guidance and the NBM Tue-next Thu
consistent with quick growing forecast spread and less then
stellar model embedded system run to run continuity. This solution
was collaborated with local Alaskan forecast offices and offshore
lows were manually deepened consistent with favorable upper
support predictability and to counter weakening effects inherent
from the blending process.
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
Hazards:
- Heavy precipitation for southern Alaska and the Alaska
Panhandle, Sat-Mon, Jan 9-Jan 11.
- High winds for southern Alaska, Sun-Mon, Jan 10-Jan 11.
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