Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Wed Mar 20 2019
Valid 12Z Sun Mar 24 2019 - 12Z Thu Mar 28 2019
Upper ridging over northwestern Canada will rebuild over
Southcentral and then the eastern interior/Yukon next week as a
closed upper high. This favors continued/renewed troughing in the
Bering Sea with a split flow south of the Gulf of Alaska. The
models/ensembles were in good agreement through much of the period
but differed on the track/timing/strength of a deep system
crossing the Aleutians late Sun/early Mon. Trend has been toward
the west but did not want to jump as far as the 12Z GFS and rather
preferred the 00Z GFS/ECMWF with their ensemble means as a
starting point. Still, potential exists for winds at least
30-40kts over the open Bering Sea waters toward western coastal
areas, though that may be limited with a farther west track. This
system is then forecast to lift northward, blocked from moving
inland too much from the ridge/closed high downstream, focusing
precipitation west of 155W (multi-inch totals in southeastern
Kenai eastward toward Cordova). Southerly flow would bring in well
above average temperatures, possibly near record highs, to much of
the interior and especially the North Slope. Next system may not
be until next Thursday into the western Aleutians.
Fracasso
Bullet points from the WPC Days 3-7 Hazards chart can be found at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
- Heavy precipitation across portions of mainland Alaska, Mon, Mar
25.
- Heavy precipitation across portions of the Alaska Panhandle and
mainland Alaska, Sat-Sun, Mar 23-Mar 24.
- High winds across portions of mainland Alaska and the Aleutians,
Mon, Mar 25.
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