Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
526 PM EST Wed Feb 10 2021
Valid 12Z Sun Feb 14 2021 - 12Z Thu Feb 18 2021
...Guidance/Uncertainty and Weather/Hazards Assessments...
Cooling Arctic trough energies in mainly dry flow are slated to
dig over the North Slope and into the Interior next week,
increasingly through an ambient upper ridge.
Meanwhile, a stormy weather pattern focus will remain across the
southern Bering Sea and the Aleutians as a series of Pacific storm
systems work through the region, rotating within a broader upper
level trough position. System potential remains heightened for
these deep lows whose wrapping flow will threaten the Aleutians
and the AKPen/Kodiak and Southwest Alaska next week. Additional
maritime system activity to the east seems more modest or at least
less certain over the Gulf of Alaska next week, but the flow could
eventually bring some organized system focusing precipitation
onshore downstream into southern and southeast Alaska. Prior to
this, expect much below normal temperatures in a post-frontal flow
environment for the interior Southeast Panhandle on the Feb 13-14
weekend.
12 UTC GFS/ECMWF and GEFS/ECMWF ensemble means are reasonably
clustered so a blend seems to offer a decent forecast for day
4-6/Sun-Tue consistent with a pattern with average predictability.
Forecast spread increases day 7/8 when the compatible GEFS/ECMWF
ensemble means still provide a reasonable larger scale flow
evolution.
Schichtel
Hazards:
- Much below normal temperatures for the interior Southeast
Panhandle on Saturday Feb 13 and Sunday Feb 14.
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