Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
430 PM EDT Sat Sep 21 2019
Valid 12Z Wed Sep 25 2019 - 12Z Sun Sep 29 2019
An increasingly amplified upper-level pattern is forecast to
dominate much of Alaska and the Bering Sea during the medium range
period. A couple of weakening occluded systems will bring some
rain near the coast of southern Alaska, with snow over the inland
sections during midweek. Then, a significant upper-level ridge is
forecast to build northward toward southern Alaska. This will
allow a conduit of moisture to spread northward from a cut-off low
in the central Pacific into southwestern Alaska during the latter
half of next week. Rain should not be excessively heavy at a
particular instance but periods of rain can be expected to persist
from midweek through next weekend across southwestern Alaska,
where total rainfall amounts could exceed 2 inches by next weekend.
Model guidance appears to be in very good agreement for the
pattern evolution over Alaska through next weekend. The WPC grid
package was derived mainly from the consensus of the 00Z ECMWF,
00Z EC mean together with the 06Z GEFS mean and the 12Z GFS,
trending toward their ensemble means for Days 7 and 8.
Kong
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