Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
325 PM EDT Fri Jun 28 2019
Valid 12Z Tue Jul 02 2019 - 12Z Sat Jul 06 2019
...Guidance and Predictability Assessment...
Todays WPC Alaskan medium range product suite was mainly derived
from a composite blend of the 12 UTC GFS/GEFS and 00 UTC
ECMWF/ECMWF ensemble mean guidance along with the 12 UTC National
Blend of Models (NBM) Tuesday into Wednesday. Model and ensemble
forecast spread increases for the remainder of this forecast
period next week to favor transition for preferece of a NBM and
GEFS/ECMWF ensemble blended solution. This offers good WPC
continuity and was collaborated with local WFOs.
...Weather/Threats Highlights...
The northern extent of the upper ridge over the Interior/North
Slope temporarily breaksdown into early next week. This indicates
that widespread portions of the Interior will be influenced by a
stronger and more active westerly mid/upper-level flow. This will
include frontal passage with associated swath of widespread
moisture and precipitation working across a ambient summertime
lead airmass.
A deeper/closed second main system brews back across the Bering
Sea and offers some heavy rain/wind threat for the Aleutians early
next week. This system now subsequently lifts northward over far
northeast Russia to the Arctic later week. This track is farther
west of Alaska than was indicated over the last couple of days.
This is due to a strong ensemble mean trend signal to rebuild a
potent and shielding ridge back over much of Alaska days 5-8. This
ride offers a wildfire and excessive heat risk over a prolonged
holiday period.
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
Hazards:
- High winds risk for the Aleutians, Mon-Tue, July 01-02.
- Heavy rain risk for the Aleutians, Wed-Thu, July 03-04.
- Enhanced wildfire risk for portions of the mainland Alaska,
Mon-Fri, Jul 01-05.
- Excessive heat for portions of mainland Alaska, Thu-Fri, Jul
04-05.
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