Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
404 PM EDT Wed Apr 03 2019
Valid 12Z Sun Apr 07 2019 - 12Z Thu Apr 11 2019
Latest models and ensembles still generally agree that a
positively tilted upper trough across western and northern Alaska
will deepen as it retrogrades into the Bering Sea. Smaller scale
details have been run to run inconsistent, but overall this favors
a cooling trend for this medium range period across much of
northern and interior Alaska as a front settles down toward
southern Alaska.
Meanwhile, an active storm track will stay mainly south of Alaska
through the next week. A consensus of guidance solutions show that
the main occluded cyclones will tend to decay as they head over
the Gulf of Alaska. However, a threat also exists for a
significant cyclone to impact the Aleutians/SW Alaska by day 7/8.
The WPC product suite was primarily derived from a composite blend
of the latest GFS/ECMWF and GEFS/ECMWF ensemble means Sunday
through Tuesday and then just the ensemble means by day 7/8 in a
period of quickly increasing guidance forecast spread and
uncertainty. Heavier precipitation will focus into the
Aleutians/SW Alaska in the circlulation around the significant
cyclone by next midweek, with additional potential along into the
Alaska Panhandle and southern coastal Alaska.
Schichtel
Bullet points from the WPC Days 3-7 Hazards chart can be found at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
Hazards
- High winds and heavy precipitation across the Aleutians and
portions of mainland Alaska, Tue-Wed, Apr 9-Apr 10.
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