Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
553 PM EDT Wed Jul 27 2022
Valid 12Z Sun Jul 31 2022 - 12Z Thu Aug 4 2022
...General Overview...
A quasi-zonal flow pattern aloft is forecast to be in place across
the North Pacific with a couple of low pressure systems expected
to affect southern Alaska. The first will likely emerge from the
Aleutians and cross the Bering through Monday night, and the next
will likely approach the Aleutians by the middle of next week.
Meanwhile, a strong surface high is forecast to remain anchored in
place north of the Arctic Coast, keeping conditions cooler north
of the Brooks Range through the beginning of the week.
...Guidance/Predictability Assessment...
The 12Z model guidance suite initially has a good overall
depiction of the weather pattern for the weekend and even going
into Monday. By early Tuesday, guidance differs on the weakening
of the Bering low across the southwest mainland, with the main
difference being a slower CMC solution. Going into the middle of
the week, the CMC is notably stronger with the ridge axis
extending north across the Gulf and even the southern mainland,
and has very limited ensemble support. The ECMWF is directly at
odds at this same general time with a well defined trough axis,
and the GFS also have a resemblance of a trough across southern
Alaska as well. Therefore, a general model blend will suffice for
Sunday and Monday, and then removing the CMC for the latter half
of the forecast period whilst increasing contributions from the
ensemble means. This results in an overall faster progression of
fronts across the Aleutians and Gulf region compared to
yesterday's forecast.
...Sensible Weather...
Seasonable temperatures are expected for a large portion of the
central and southern mainland for the weekend, with some 70s for
highs likely for the lower elevations of the Interior, followed by
a slight cooling trend as increased cloud cover from the low
pressure systems moves in. This will also include coastal
portions of the state and extending eastward to include the
southeast Panhandle region. Even the northern third of the state
will likely get to enjoy a moderating trend in the recent cold
weather as southerly winds ahead of the next storm system advect
warmer air across the region. In term of precipitation, scattered
to perhaps numerous showers are expected across parts of the
interior, the southern Mainland, and the Alaska Peninsula as a
surface low pressure system lifts northward through the region.
The good news is no areas of hazardous weather are currently
anticipated at this time.
Hamrick
Additional 3-7 Day Hazard Information can be found on the WPC
medium range hazards outlook 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