Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
235 PM EDT Sat Jun 29 2019
Valid 12Z Wed Jul 03 2019 - 12Z Sun Jul 07 2019
...Guidance and Predictability Assessment...
The WPC Alaskan medium range product suite was mainly derived from
a composite blend of well clustered 12 UTC GFS and the 00 UTC
NAEFS/ECMWF/ECMWF ensemble mean along with the 12 UTC National
Blend of Models (NBM) Wednesday-Friday. Model and ensemble
forecast spread increases next weekend to favor transition for
preferece of a NBM, ECMWF and GEFS/NAEFS/ECMWF ensemble mean
blended solution. This offers good WPC continuity and was
collaborated with local WFOs.
...Weather/Threats Highlights...
A low/trough will work across the Bering Sea to offer some heavy
rain/wind threat for the Aleutians through midweek. This
lead/complex system tends to lift northward over far northeast
Russia and into the Arctic later next week. This track is well
west of mainland Alaska due to a massive sheilding upper ridge
slated to dominate most Alaskan weather through this forecast
period. This ridge offers a widespread wildfire and excessive heat
risk over the mainland through the upcoming prolonged holiday
period. This ridge is impressive with heights building to more
than 3 standard deviations above normal that will likely lead to
some record temperatures.
Schichtel
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