Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
754 PM EDT Fri Apr 26 2024

Valid 12Z Tue Apr 30 2024 - 12Z Sat May 04 2024


...Guidance Evaluation and Preferences...

The latest guidance did not resolve the large degree of spread
that has been persistent for days now. What has been somewhat
consistent is the pattern with multiple lows/surface fronts
parading east from the Bering, across the Aleutians toward the
Southeast. There is a slot of cold air aloft within this mean lows
which would support keeping this pattern around for awhile longer.
The 12 UTC GFS/ECMWF model solutions continued to be the best
clustered with ensemble means for the extended period. Emphasis
was shifted from the GFS/ECWMF to the GEFS/ECMWF ensemble means.
WPC product continuity is reasonably maintained in this fashion,
albeit with a trend toward deeper Aleutian lows given pattern
history and potentially quite favorable upper support.

...Weather/Hazards Highlights...

Multiple weak low pressure frontal systems will queue west to east
across the Aleutians and Gulf through next weekend which focus
areas of modest maritime winds/waves/rainfall that could clip
southern tier coastal areas, albeit in an overall benign weather
pattern. A vast portion of the state will experience above
seasonal average temperatures for the start of the month
particularly the Interior where anomalies will be the highest. To
the north of a front settling over the north-central mainland,
cold high pressure over the Arctic may keep temperatures near to
somewhat below normal, especially across the North Slope and
guidance shows some spotty/modest precipitation. Locations near
the Southcentral coast and northern Panhandle may also see near or
slightly below normal readings.

Meanwhile, guidance has been trending toward the development of
much deeper low pressure systems to mainly affect the Aleutians
and Bering Sea early next week and into later next week. These
offer potentially hazardous multi-day periods with enhanced wind
flow/waves and rainfall to monitor. Slow eastward progressions of
these organized systems within the amplified pattern may lead to
enhanced lead frontal inflow and precipitation into west/southwest
Alaska and downstream with re-developments into the Alaska
Peninsula/Kodiak Island and then Southcentral Alaska late next
week.

Campbell/Schichtel


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