Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 PM EDT Tue Jul 02 2019
Valid 12Z Sat Jul 06 2019 - 12Z Wed Jul 10 2019
...Record heat for much of Southcentral Alaska...
...Guidance and Predictability Assessment...
An intense upper high will only slowly weaken and drift westward
across western Alaska and perhaps into the Bering Sea next week.
The ensembles were in good agreement on maintaining the upper high
through the period, with slow movement due to the combination of a
large scale rex block and omega block. A mid level shortwave
atop the upper high in the Beaufort Sea will likely allow a front
to move into northern AK, bringing in cooler air to
northern/northeastern areas next week.
The 06-12z GFS moves systems faster than the 00z ECMWF and 00z
ECMWF Ensemble Mean and 06z GEFS Mean, including the
aforementioned wave, and subsequent north Pacific cyclones next
week. With better than average overlap among the 00z ECMWF
Ensemble Mean, 06z GEFS Mean, and 00z Canadian ensemble mean, a
consensus based approach should work well. The ECMWF Mean and 06z
GEFS Mean were blended with the operational 00z ECMWF for the
fronts/sea level pressure forecasts, and gridded forecasts for
temperatures, dew points, etc.
...Weather/Threats Highlights...
The upper high will favor well above average temperatures with
potential for daily record highs in many locations across southern
mainland AK. Daily high temperatures may approach or exceed 90F
in the interior this weekend. Precipitation chances will be
limited to near the Brooks Range and northeastern Alaska as the
front works its way eastward/southeastward, and then into
southeastern areas and the Panhandle as the front dips southward.
The dry/warm conditions in the rest of mainland will favor a
wildfire risk through the period.
Petersen
- Enhanced wildfire risk across portions of the the Alaska
Panhandle, mainland Alaska, and the Aleutians, Fri-Tue, Jul 5-Jul
9.
- Much above normal temperatures across portions of mainland
Alaska, Sat-Tue, Jul 6-Jul 9.
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