Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
303 PM EDT Fri Jul 19 2019
Valid 12Z Tue Jul 23 2019 - 12Z Sat Jul 27 2019
Troughing over northeastern Russia into the Bering Sea will slowly
ease southeastward into western Alaska/AKPen as an upper low
weakens in the Gulf. A Rex block pattern over NW Canada (upper
high to the north of the Gulf low) is forecast to break down as it
gets pushed to the east. The models/ensembles were in reasonable
agreement overall, with the GFS/ECMWF clustering better with their
ensemble means (and each other) than the UKMET/Canadian. There
were differences in the handling of systems through the Bering
which was evidence in the large ensemble spread and thus lower
confidence. Majority ensemble mean weighting should serve to
minimize future shifts in the guidance.
Lead system tracking toward the Panhandle next week will maintain
a rather wet pattern there after the surface low/trough dissipate
Wednesday. Precipitation amounts over the 5-day period may exceed
1-2" especially in favored areas. Lighter to modest precipitation
is expected over much of the rest of the state given the several
systems in the domain--into the NW areas/interior Tue/Wed, a
Bering system into SW AK Thu/Fri, and the north Pacific system
Tue/Wed affecting the Aleutians initially then into the Panhandle.
Southcentral may escape the brunt of the rainfall until later next
week as troughing moves toward the area. Temperatures near/above
average to start the period (owing to ridging across the interior)
will trend back toward within a few degrees of average later next
week.
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
No significant hazards are expected over Alaska during this
forecast period.
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