Alaska Extended Forecast Discussion
National Weather Service College Park MD
544 PM EDT Sun Jun 8 2025
Valid 12Z Thu 12 Jun 2025 - 12Z Mon 16 Jun 2025
...Guidance Evaluation/Preferences...
The WPC Alaskan medium range pressures, winds, PoPs, and QPF were
mainly derived from a composite blend of well clustered guidance
of the 12 UTC GFS/ECMWF/UKMET/Canadian models early on, with some
ensemble mean contribution from the EC/NAEFS to help deal with the
detail issues that arise in and near the Bering Sea and with a
retrograding system across the far northeast Pacific/Gulf of AK.
Other grids were more reliant on the 19z NBM. This solution
maintains reasonable product continuity in an active pattern. The
guidance offers reasonably similar larger scale flow evolutions
into next weekend with persistent ridging across the AK interior
and with a persistent deep layer low near the southern Bering
Sea/Aleutians. The least predictable system in this pattern is the
cold low stalling near the AK Panhandle that the guidance
suddenly retrogrades due to a more isolated closed low in the
southern Bering and stronger/elongated ridging across interior AK
and northwest Canada that would force it west to west-northwest,
in today's version of the flow pattern. It remains to be seen if
the guidance has locked in on this pattern as of yet, so
confidence appears lower, no better than average.
...Weather/Hazards Highlights...
Light precipitation and chances of such linger across Southeast
AK and the AK Panhandle, now that the system is no longer forecast
to drop southeast, out of the picture. They could fade by next
Sunday. Rain chances are fairly high across western AK and the
Aleutians as disturbances/low pressure systems move through the
Bering Sea around the eastern side of the mean trough, which
appears narrower than in Saturday's guidance. Periods of gales
are expected near the Aleutians and AK Peninsula with gales also
possible near the northwest coast; wind gusts are expected to
remain below storm-force. As the flow becomes more southeast to
east-southeast across southern mainland AK Friday through next
weekend, disturbances in the flow and associated moisture
increases will need to be watched for thunderstorm potential.
Across the eastern interior, NBM probabilities of 80F+ high
temperatures remain likely, which has led to low to mid 80s being
explicitly forecast late week into next weekend. Probabilities of
90F+ are non- zero in a couple spots, but have not trended upward
since Saturday. Stay tuned.
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