Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
642 PM EDT Sun May 28 2023
Valid 12Z Thu Jun 1 2023 - 12Z Mon Jun 5 2023
...Synoptic Overview...
An upper level low is forecast to be in place across the Gulf
through the end of the week with some showers from the southern
coastal areas to the southeast Panhandle region, and this low
drops southward away from the region by the weekend. An anomalous
arctic closed low is expected just north of the Arctic Coast on
Thursday and this slows moves away towards the northwest through
Friday and into the weekend. The departing arctic low/trough
allows an upper ridge axis to steadily build across much of the
mainland with a pronounced warming trend expected. Meanwhile, a
storm system approaches the Bering and the Aleutians by Sunday
with more showers.
...Guidance Evaluation/Preferences...
The 12Z model guidance suite is in good overall agreement on the
main synoptic scale features through the end of next week. One of
the main differences noted is a stronger upper ridge and
corresponding warmer temperatures in the GFS compared to the model
consensus next weekend and beyond, so temperatures were slightly
reduced from the NBM in the Saturday-Monday time period across the
Interior and North Slope areas. The fronts/pressures incorporated
a nearly general deterministic blend through Friday, followed by
slightly less of the GFS/CMC by next weekend whilst increasing
contributions from the ensemble means to about half by that time.
...Sensible Weather and Potential Hazards...
Much of the Southeast and southern coast will likely have ongoing
light to occasionally moderate showers through Friday, owing to
the slow moving disturbances over the northern Gulf. However, no
areas of significant rainfall or snow are currently expected for
this time period. A more concentrated band of showers may develop
across the Aleutians next weekend as the next storm system
approaches. Temperatures will generally be near average through
Friday, with some negative anomalies expected across the North
Slope Thursday in closer proximity to the arctic low. However, a
noteworthy warming trend is likely to commence Friday night and
especially into next weekend as a warm front lifts northward with
upper level ridging in place. Afternoon highs will likely be in
the 65-75 degree range for many of the lower elevations of the
central and eastern Interior by Sunday and Monday, and overnight
lows in the 40s.
Hamrick
No significant hazards are expected over Alaska during this
forecast period.
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