####018003167####
FXAK02 KWNH 172346

PMDAK 



Alaska Extended Forecast Discussion

NWS Weather Prediction Center College Park MD

745 PM EDT Fri May 17 2024



Valid 12Z Tue May 21 2024 - 12Z Sat May 25 2024



...Guidance Evaluation and Preferences...



The 12Z model guidance suite has a good overall depiction of the

synoptic scale pattern across the Alaska domain for the beginning

of next week, with mainly mesoscale differences noted with the

Bering Sea low and developing triple point low near the Alaska

Peninsula.  The UKMET differed the most from the consensus with a

farther east solution with the Bering Sea low on Tuesday, and even

more so with the next low arriving behind it.  Going into

Thursday, the CMC becomes a slower solution with the second Bering

Sea low compared to the ensemble means, and the GFS is a weaker

solution.  By the end of the forecast period next Saturday, there

is a general signal for a Gulf low developing among the

deterministic guidance, but greater differences across the Arctic

where the ECMWF indicates more of a surface high whereas the GFS

depicts a surface trough. 



The WPC fronts/pressures forecast was primarily derived from a

GFS/ECMWF/CMC compromise with a little UKMET on Tuesday, followed

by gradually increasing percentages of the ECENS and GEFS through

the end of the week to about 50% by next Saturday, while still

maintaining the GFS/ECMWF and a little of the CMC. 



...Overview and Weather/Hazards Highlights...



The developing triple point low over the northern Gulf on Tuesday

is expected to result in generally unsettled conditions with

mainly nuisance level precipitation owing to moist onshore flow,

but below hazardous level criteria for the southern coastal areas.

 The heaviest QPF is expected for the southern Kenai Peninsula to

the Prince William Sound region through Wednesday, followed by a

drier weather pattern through Friday before rain/snow chances

increase once again for next Saturday, depending on how the next

Gulf low evolves. Elsewhere across the state, periods of light to

occasionally moderate rain can be expected across western mainland

Alaska as southerly flow advects moisture northward ahead of the

Bering Sea low through midweek, although most of the North Slope

should remain mostly dry.  Temperatures are forecast to be rather

pleasant for most Interior locations, with highs generally in the

60s for the lower elevations, and lows from the upper 30s to

middle 40s.  Readings closer to the southern coast will generally

be in the upper 40s to middle 50s, and in the 30s for the Arctic

Coast.



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



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



$$