Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
425 PM EDT Sat Jun 23 2018

Valid 12Z Wed Jun 27 2018 - 12Z Sun Jul 01 2018

The beginning of this forecast period on Wednesday over the Alaska
domain offers reasonable overall deterministic and ensemble mean
agreement with respect to a weakening low pressure system over the
southern Bering Sea, a surface high north of the Arctic Coast, and
a high pressure ridge extending northward over the Alaska
Panhandle region.  The latest 12Z model guidance suggests that the
Bering Sea low is expected to move rather slowly and dissipate
over the eastern Aleutians.  The latest CMC run is to the south of
the model consensus with the Bering Sea low, and the GFS is
slightly slower than the ECMWF.  The models are still having
difficulty resolving a triple point low that is likely to form
over the Gulf by Thursday, and this provides the greatest
uncertainty in this forecast period.

The forecast for the Gulf region depended more on a model
consensus, including the 00Z ECMWF ensemble mean, which takes this
new low towards the Panhandle on Thursday and then weakens.  This
will keep the focus for precipitation along the Aleutians and the
southern Kenai peninsula, and another focus over the
central/southern Panhandle.  Some scattered showers and perhaps a
few thunderstorms can be expected over parts of the Interior, and
dry conditions for the northern third of the state.  High
temperatures in the 60s and lower 70s can be expected for most of
the lower elevation locations inland, and mid 50s to lower 60s for
the coastal areas, except 40s for the Arctic Coast.

D. Hamrick


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

http://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
http://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html