Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
643 PM EDT Tue May 14 2024
Valid 12Z Sat May 18 2024 - 12Z Wed May 22 2024
...Guidance Evaluation and Preferences...
12 UTC GFS/ECMWF/UKMET/Canadian model solutions seem decently
clustered Saturday into early Sunday, but even a favored composite
offers less than stellar continuity from yesterday. The latest
solutions are overall less progressive. This trend may be
reasonable given overall flow amplitude and newer data
initialization in a pattern with stream flow interaction
sensitivity. Later, prefer better cycle to cycle consistent 12 UTC
NAEFS/ECMWF ensemble means solutions for later Sunday through next
Wednesday. Manually applied adjustments to forecast products tend
to offset affects of system weakening inherent to a composite
blending/means process. Overall, predictability is below normal,
but may be in the process of improving.
...Overview and Weather/Hazards Highlights...
The latest guidance cycle indicates now highlights the
southeastward digging of an amplified Arctic stream upper trough
and surface low/frontal system through the Bering Sea and
Southwest Alaska/southern Interior to the northern Gulf of Alaska
this weekend. This should spread a swath of enhanced winds and
moderate rains across the broad region and into Southeast Alaska
before exiting into Monday. The weather pattern remains unsettled
next week over the Mainland as current upper ridging is eroded by
a series of uncertain upper systems with height falls. Meanwhile
to the south, also uncertain impulse energies and lighter weather
focus will eject downstream across the Aleutians and the Gulf well
in advance of a much more amplified upper trough and associated
surface systems slated to work across the northern Pacific and
Aleutians/Bering Sea to further monitor for growing predictability
and hazardous weather focus as energies and rains/winds work
toward the mainland in about a week.
Schichtel
Additional 3-7 Day Hazard Information can be found on the WPC
medium range hazards outlook 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