Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
520 PM EDT Thu Mar 24 2022
Valid 12Z Mon Mar 28 2022 - 12Z Fri Apr 01 2022
...Pattern Overview and Weather/Hazard Highlights...
A pair of well organized storm systems will make weather headlines
for the extended forecast period, and possibly a third surface low
entering the Gulf region by the end of next week. The organizing
low over the Gulf early next weekend is expected to bring gusty
winds, high waves, and rounds of moderate to locally heavy
precipitation from the Kenai Peninsula to the southeast Panhandle
region. Strong onshore flow that is orthogonal to the terrain
will enhance precipitation totals for the windward areas. The
Aleutians will also be affected by another well organized low,
with a strong southerly fetch of wind across the central and
eastern Aleutians for the Tuesday to Wednesday time period along
with periods of rain, although not currently expected to reach
hazardous criteria. In terms of temperatures, most of the
mainland should enjoy readings above average through the weekend,
followed by a return to seasonal to below average readings for
some areas through next Wednesday. It will remain quite cold for
locations north of the Brooks Range.
...Guidance/Predictability Assessment...
The 12Z UKMET/CMC/ECMWF guidance suite remains in good agreement
on the overall synoptic scale pattern through the beginning of
next week, and these models are now supporting the development of
a triple point low that tracks towards the southeast panhandle by
late Tuesday/early Wednesday. The latest 12Z run of the GFS is
now closer to the model consensus with the Gulf system early in
the forecast period, in contrast to previous runs that had the low
well to the southwest of the non-NCEP guidance. The GFS becomes
stronger with another low approaching the Gulf region from the
central Pacific by the end of the week. In regards to the
Bering/Aleutians storm system, the GFS is only slightly displaced
to the other guidance, and it is also more in line compared to
yesterday.
The WPC forecast was primarily derived from a multi-model
deterministic blend through Tuesday night, with slightly greater
weighting to the CMC/ECMWF/UKMET guidance. There is a gradual
increase in the ensemble means for the second half of the forecast
period to account for normal levels of increasing uncertainty.
Hamrick
Hazards:
- Heavy precipitation across portions of the Alaska Panhandle,
Mon-Tue, Mar 28-Mar 29.
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
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