652
FXAK02 KWNH 242146
PMDAK

Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
546 PM EDT Fri May 24 2024

Valid 12Z Tue May 28 2024 - 12Z Sat Jun 01 2024


...Guidance Evaluation and Preferences...

The latest model guidance shows reasonably good agreement across
the region, given the typical model biases and uncertainty
especially by the latter portions of the period. To start, the 500
mb height pattern is expected to feature a lingering closed low
off Southeast Alaska while another compact closed low
pivots/retrogrades across the northwest portions of the Mainland.
That feature is expected to gradually absorb/phase with another
shortwave trough/closed low undercutting it over the Aleutians and
eventually forms a sprawling closed low over the western Mainland
and Aleutians by the middle of the forecast period. Finally, by
the end of the forecast period, the consensus among the available
deterministic and ensemble guidance is for lower heights/troughing
over the western Mainland and Aleutians while some ridging may
develop/extend across the northern/northeast state. At the
surface, areas of low pressure are likely to move through the
southern regions with some potential for a deeper feature to
develop toward the end of the forecast period across the western
Aleutians. Overall, the details in the troughing (embedded vort
maxes) and specifics about the low pressure track and timing will
have to be resolved in later forecasts.

With this in mind, the WPC blend favored the ECMWF and ECENS mean
generally throughout the period though at the beginning of the
period, a near equal blend of the ECMWF/UKMET/CMC/GFS was included
given the reasonably good agreement.


...Weather/Hazards Highlights...

No significant weather hazards are forecast through the period
with rain amounts generally remaining light to modest overall.
Parts of the Panhandle, the Aleutians, and perhaps the southern
Mainland may pick up more substantial amounts of precipitation
given the favorable troughing and expected low tracks. River
flooding is a possibility in a couple of spots as ice breaks
up--see the Alaska-Pacific River Forecast Center for details.

Interior Alaska is likely to see the mildest temperatures across
the state, with highs generally in the 60s to low 70s as the week
progresses with a warming trend. The Brooks Range to North Slope
should also see temperatures warm with time, from around to above
the freezing mark for highs in the Arctic Coast communities. For
the southern coast, temperatures at least for highs are forecast
to stay below normal, with 40s and 50s for the most part.


Tate/Taylor


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

$$