Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
314 PM EDT Sun Jun 09 2019
Valid 12Z Thu Jun 13 2019 - 12Z Mon Jun 17 2019
Two slowly moving upper lows to the north and south of the
mainland will favor weak ridging across the interior during the
period. The models/ensembles have been in general agreement in
principle during the past several cycles, but the ECMWF/ECMWF
ensemble mean (EPS) have exhibited greater stability than the
GFS/GEFS or Canadian/GEPS. Using a 50/50 blend (ECMWF/EPS)
maintained good continuity from the previous forecast with only a
change toward quicker progression through the northern Pacific
with a system potentially wrapping into the Gulf next weekend (low
confidence with this scenario based on upstream conditions).
Lead system south of the Aleutians on Thursday will bring
rain/windy conditions through the islands as the frontal system
moves east-northeastward. Parent low is forecast to stall near the
AkPen or eastern Aleutians as precipitation spread along
Southcentral into the Panhandle. Best focus for rainfall will be
from Cold Bay east-northeastward on southeast-facing areas of
Kodiak Island and the Kenai Peninsula. Height falls will be less
intense into the Panhandle as the system loses upper support in
advance of moving into Southeastern portions. Slow moving upper
low invites another wave to develop on its south side and
potentially move northeastward toward Kodiak early next week, but
confidence is low as the upstream flow across the Pacific is quite
uncertain due to several players aloft over eastern Asia.
Fracasso
Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards 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