Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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735 FXAK02 KWNH 302343 PMDAK Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 742 PM EDT Sun Jun 30 2024 Valid 12Z Thu Jul 04 2024 - 12Z Mon Jul 08 2024 ...Overview and Guidance Evaluation/Preferences... The latest runs of guidance continue to lock on to the idea of a deep closed low over the Gulf of Alaska that will move southward with time as the ridge over the Pacific builds northward all the while a shortwave trough skirts across the Arctic and northern parts of the Mainland. The GFS is persistent in lagging/much further west of the consensus while today the ECWMF began to favor the right/faster side of the cluster. The CMC has trended back toward the middle of the pack and presents a fairly deep low feature. The EC ensemble means and the GEFS means are positioned closer to the CMC than their parent models but are noted to be 30-40 mb weaker than the deterministic guidance. An initial starting point of the UKMET,CMC, GFS and ECWMF was used before dropping the UKMET and leaning a little heavier toward the CMC solution. The ensemble means were included around day 5 and continued through the entire extended period. This combination provided a deeper, slower low feature over the Gulf of Alaska and provided a more pronounced frontal system across the Arctic region. ...Weather/Hazards Highlights... Much of the Aleutians and the Southeast will have mostly light or no precipitation through much of the extended period; however there will be increases rain for part of the Southern Coast this coming weekend. Rain/thunderstorms will steadily increase in coverage and amounts across the western/northwest part of the state while spreading across the Interior. An increase in wind speeds and gusts across northern parts of the state could aggravate the spread of the numerous wildfires that are scattered across the Interior. Of late, the air quality has been very poor from the smoke and the increasing wind speeds should help thin some of the smoke out for a modest improvement of air quality. The increase in rain potential however will help reduce and contain the wildfires while providing beneficial moisture to the region. Daily highs are expected to be mostly in the 60s and 70s across lower elevations of south-central and portions of Interior Alaska, 50s and 60s in most coastal areas, 50s and 40s across the North Slope, and mid to upper 40s in the Aleutians. Higher elevations in the terrain across south-central and southeast Alaska should fall below freezing overnight. Campbell 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 $$