Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
648 PM EDT Thu Nov 02 2023
Valid 12Z Mon Nov 06 2023 - 12Z Fri Nov 10 2023
...Heavy Precipitation Threat from Southern to Southeast Alaska
Next Week...
...Guidance Evaluation and Preferences...
Model and ensemble solutions offer lower than normal forecast
spread through medium range time scales, bolstering forecast
confidence. A preferred composite of best clustered guidance from
the 12 UTC GFS/ECMWF/Canadian models and the 12 UTC
GEFS/NAEFS/ECMWF ensemble means seems to offer a good forecast
basis for a mid-larger scale system and pattern evolution with
seemingly average to better predictability and continuity. Manual
adjustments applied to the composite will re-deepen best organized
systems as consistent with individual predictability as an offset
to the inherent weakening as per the blending process. WPC product
continuity is well maintained in this manner.
...Overview and Weather/Hazards Highlights...
A series of dynamic/amplified upper troughs and deepened surface
lows/frontal systems are expected to work from the southern Bering
Sea and northern Pacific into the Gulf of Alaska next week. This
will spread generally modest activity into the Aleutians and
Southwest Alaska into early next week and again there by later
next week with system progressions. Additionally, enhanced winds
and deeper lead/rotating moisture feed looks to increasingly fuel
development of a heavier precipitation pattern from Southcentral
to Southeast Alaska, especially from mid-later next week with
northern Gulf of Alaska storm low formations. This will include
threats for coastal rains and inland/mountain snow.
Meanwhile, lingering lowered heights and periodic pockets of
modest moisture rotating over an unsettled Interior and North
Slope may support scattered light snows next week with protracted
easterly fetch winds offering blowing snow situations to monitor
locally.
Schichtel
Hazards:
- Heavy precipitation across portions of the Alaska Panhandle and
southern Alaska, Tue-Thu, Nov 7-Nov 9.
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