Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
328 PM EDT Wed Jun 05 2019

Valid 12Z Sun Jun 09 2019 - 12Z Thu Jun 13 2019

Positive height anomalies are expected to persist across the
Bering Sea through early next week before perhaps weakening some.
Meanwhile, a ridge axis will rebuild along the west coast of
Canada extending into the interior of Alaska. A strong Pacific
upper-level jet will keep a relatively active storm track across
the North Pacific near/south of the Aleutians and into the Gulf of
Alaska.

Model/ensemble consensus has improved substantially during the
past 24 hours for the extended forecast period across Alaska. A
majority deterministic blend including the GFS/00Z ECMWF was used
as a forecast starting point early in the forecast period. Model
consensus supports a weakening low pressure system moving north
into the Gulf of Alaska during the Mon-Tue time frame, and
solutions were reasonably well clustered for this system.
Models/ensembles also show some consensus that another,
potentially deeper low pressure system may track near/just south
of the Aleutians during the Tue-Thu time frame. Differences among
the deterministic solutions increase especially by Wed-Thu, but
ensembles also show a similar idea. Thus, a gradual trend toward
heavier weighting of ensemble means in the forecast was preferred,
with majority ensemble means by days 7-8 (Tue-Wed). Farther north,
consensus has improved that an upper ridge axis across the
Interior should be sufficient to keep the majority of arctic
shortwave energy from making significant inroads southward into
the state. A more significant arctic upper low may approach the
northern coast of Alaska by the middle of next week, although the
majority of solutions keep it offshore through the end of the
forecast period.

Ryan


Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards chart at:
<a href="https://www.wpc.ncep.noaa.gov/threats/threats.php"><u>https://www.wpc.ncep.noaa.gov/threats/threats.php</u></a>

- No significant hazards are expected over Alaska during this
forecast period.


WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can also be
found at:

<a href="https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif"><u>https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif</u></a>
<a href="https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml"><u>https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml</u></a>
<a href="https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html"><u>https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html</u></a>