Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
712 PM EDT Tue Jun 25 2024

Valid 12Z Sat Jun 29 2024 - 12Z Wed Jul 03 2024

...Overview and Guidance Evaluation/Preferences...

The ensemble means from the GEFS, EC, and CMC appear in good to
excellent agreement on the evolution of the upper-air pattern
across Alaska through the medium-range period.  In this Rex Block
configuration, an upper ridge will have a tendency to close off
across the northern half of Alaska while an initially deep Bering
Sea low weakens and slides under the ridge toward the Gulf of
Alaska early next week.  The EC mean, particular the 12Z run, is
showing a faster ejection of the weakened upper low across the
Gulf of Alaska early to middle of next week in better agreement
with the faster GEFS mean.  The latest CMC mean also shows a
faster motion for this low while building a stronger ridge behind
the low over the Aleutians.

With a major network outage continuing at NCWCP, no 500mb charts
for Alaska were created today.  Surface prognostic charts were
created after some modifications to yesterday's charts with manual
creation of the Day 8 isobars and fronts.  The hemispheric charts
were not created either.  The Alaskan grids are to be created from
an auto script at 23:05Z.  Whether these grids will be
successfully sent out remains to be seen.


...Weather/Hazards Highlights...

This pattern will favor the Aleutians and AK Peninsula to be
rainy, as the lingering Bering Sea cyclone gradually slides across
the Aleutians reaching into the Gulf of Alaska by early next week.
 The double-barrel system will allow for modest rainfall in its
vicinity.  Winds should generally peak in the 30 kt (35 mph) range
at times across the Arctic Coast and coastal areas.  The terrain
in south-central and northern AK are expected to have the best
chance of showers and thunderstorms. There is the possibility of
dry lightning strikes during the afternoons and evenings which
would increase the risk for fire weather concerns given the dry
fuels across the region.  Ridging across the Mainland will
maintain warm to hot temperatures.  Afternoon maximums should lie
the 80-90F range for the most part across the eastern interior
sections.  Highs mostly in the 60s and 70s are expected across
lower elevations of south-central AK, with mainly 50s and 60s in
most coastal areas, 50s and 40s across the North Slope, and mid to
upper 40s in the Aleutians.  The North Slope will be cool
overnight with lows in the 30s, while highs will approach 60
degree not too far inland from the shore.  Higher elevations in
the terrain across south-central and southeast AK should fall
below freezing overnight. 

Kong/Roth


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