Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
501 PM EDT Mon Jun 24 2024
Valid 12Z Fri Jun 28 2024 - 12Z Tue Jul 02 2024
...Overview and Guidance Evaluation/Preferences...
The flow around AK morphs back and forth into and out of a Rex
Block configuration as deep layer lows occasionally move under its
southern side. Ridging persists across much of mainland AK. The
12z Canadian/12z ECMWF knocked down the strength of the ridge
across AK more than the other guidance, including the 00z
ECMWF/12z NAEFS means, so lowered their weighting late this
weekend/early next week. The 12z runs of the ECMWF, UKMET,
Canadian, and GFS otherwise fit in reasonably well with the 12z
NAEFS and 00z ECMWF ensemble means. For the winds, pressures, 500
hPa heights, and QPF persisted with a starting point of primarily
the 12z runs of the ECWMF, GFS, and Canadian models before adding
in the ECWMF and GEFS ensemble means, up to 50% means late in the
period. The remainder of the grids were more heavily based on the
19z NBM, with some inclusion of the 12z ECMWF and 12z ECMWF
ensemble mean.
...Weather/Hazards Highlights...
This pattern will favor the Aleutians and AK Peninsula to be
rainy, as the Bering Sea cyclone lingers and a new cyclone is
escorted under its base late in the week. The pair of systems
allow for modest rainfall in their vicinity. Winds should
generally peak in the 30 kt (35 mph) range at times across the
Arctic Coast and coastal areas. The terrain in south-central and
northern AK are expected to have the best chance of showers and
thunderstorms. There is the possibility of dry lightning strikes
during the afternoons and evenings which would increase the risk
for fire weather concerns given the dry fuels across the region.
Ridging across the Mainland will maintain warm to hot
temperatures. Afternoon maximums should lie the 80-90F range for
the most part across the Interior. Highs mostly in the 60s and
70s are expected across lower elevations of south-central AK, with
mainly 50s and 60s in most coastal areas, 50s and 40s across the
North Slope, and mid to upper 40s in the Aleutians. The North
Slope will be cool overnight with lows in the 30s, while higher
elevations in the terrain across south-central and southeast AK
should fall below freezing overnight.
Roth
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