Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
639 PM EDT Sat Apr 27 2024

Valid 12Z Wed May 01 2024 - 12Z Sun May 05 2024

...Guidance Evaluation and Preferences...

12 UTC GFS/ECMWF/Canadian model solutions seem best clustered with
ensemble means through medium range time scales, albeit with less
than ideal forecast spread with embedded systems. Accordingly,
overall predictability seems close to average. A composite
solution lends a solid forecast basis, but shifted focus to the
more compatible NAEFS/ECMWF ensemble means next weekend amid
faster growing variances. WPC product continuity is decently
maintained in this fashion, albeit with a trend toward slightly
more progressive Pacific low/frontal system progressions.

...Weather/Hazards Highlights...

Multiple organized low pressure/frontal systems and
supporting/amplified upper lows/troughs will queue and progress
generally west to east across the Bering Sea/Aleutians and North
Pacific into the Gulf of Alaska through next weekend to focus
areas of modest maritime winds/waves/rainfall that could clip
western to southwestern through southern tier coastal areas,
albeit in an overall benign weather pattern inland. A vast portion
of the state will experience above seasonal average temperatures
for the start of the month particularly much of the Interior where
anomalies will be the highest. Additional upper troughing over the
Arctic Ocean may settle down into the northern tier of the state.
In this pattern, areas to the north of a surface front settling
over the north-central mainland in cold high pressure over the
Arctic should keep temperatures below normal, especially across
the North Slope and into the northern Interior. Guidance shows
some spotty light precipitation.

Meanwhile, guidance has been trending toward the development of
much deeper low pressure systems to mainly affect the Aleutians
and Bering Sea into mid-later next week. These offer potentially
hazardous multi-day periods with enhanced wind flow/waves and
rainfall to monitor. Slow eastward progressions of these organized
systems within the amplified pattern may lead to enhanced lead
frontal inflow and precipitation into west/southwest Alaska and
downstream with re-developments into the Alaska Peninsula/Kodiak
Island and then Southcentral Alaska late next week/weekend.

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