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Prognostic Meteorological Discussion (PMD)

Issued by National Weather Service (NWS)

                            
000
FXAK02 KWNH 171729
PMDAK 

Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
128 PM EDT Mon Jun 17 2019

Valid 12Z Fri Jun 21 2019 - 12Z Tue Jun 25 2019

The ensemble means are indicating a broad upper level ridge across
mainland Alaska and an upper level trough axis extending from the
Bering Sea to the northern Gulf of Alaska on Friday, along with a
well defined trough from the polar vortex just north of the Arctic
Coast.  The upper low embedded within the southern portion of that
trough should track eastward across the northern Gulf of Alaska
through Saturday, followed by increased ridging.  There is a broad
model signal for an upper low near the Kamchatka Peninsula and the
western Aleutians this upcoming weekend.  This will have an effect
on the downstream ridge axis across Alaska for the second of the
forecast period as shortwave perturbations pivot around this broad
upper low.  There is a general consensus that this pattern will be
slow to change for this weekend and the beginning of next week as
the ensemble means are hinting at an omega block developing.

In terms of sensible weather, most locations are expected to
remain dry, with the best chance for any showers to be across the
elevated terrain of southern Alaska.  Some showers will be
possible across northern Alaska on Saturday, and more widespread
rain will be possible across the Aleutians as the next oceanic
storm passes by to the south.  Pleasant temperatures are expected
with a high quality airmass in place, with highs generally above
normal with readings from the upper 60s to lowers 80s across
inland areas, and colder near the coasts. 

Hamrick


Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

No significant hazards are expected over Alaska during this
forecast period.


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

$$