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FXAK02 KWNH 182350

PMDAK 



Alaska Extended Forecast Discussion

NWS Weather Prediction Center College Park MD

749 PM EDT Sat May 18 2024



Valid 12Z Wed May 22 2024 - 12Z Sun May 26 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 middle of

next week, with mainly mesoscale differences noted with the Bering

Sea low and developing triple point low over the northern Gulf. 

The UKMET was more in line with the consensus compared to its

faster solution from yesterday.  Going into Friday, the CMC

becomes a slower solution with the second Bering Sea low compared

to the ensemble means, but still close enough to be a part of the

model blend.  By next weekend, there is a general signal for a

Gulf low developing among the deterministic guidance, and another

trough approaching the western Aleutians by Sunday.  



The WPC fronts/pressures forecast was primarily derived from a

multi-deterministic model compromise for Wednesday and Thursday,

followed by gradually increasing percentages of the ECENS and GEFS

going into next weekend, 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 midweek 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 weekend, 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 and colder.  Temperatures are forecast to

be rather pleasant for most Interior locations, with highs

generally in the 60s to perhaps 70 degrees 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



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