Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
251 PM EDT Fri Apr 19 2019

Valid 12Z Tue Apr 23 2019 - 12Z Sat Apr 27 2019

...Guidance/Predictability Assessment and Weather
Highlights/Hazards...

It remains the case that model variance grows quickly next week,
mainly with small-mid scale offshore lows. GEFS/ECMWF ensembles
seem reasonably compatable early next week, but even the means
still become quite varied by later next week.

The pattern next week is not very active stormwise, but may be
highlighted by a meandering surface low set to spin over the
northern Gulf of Alaska. A main risk of wrapping precipitation
will be over the Panhandle early week with heaviest amounts over
favored terrain. The low will be supported by a mean upper closed
low/trough over the Gulf whose position will be reinforced from
upper trough energies digging from an unsettled southwest
Alaska/AKpen and the southern Interior Alaska where modest snows
are expected early week. The 12 UTC GFS/ECMWF offer a reasonable
solution early week before solutions diverge. There is now less
signal for renewed storm potential to effect the Aleutians
mid-later next week considering suppressed/sheared 12 UTC GFS
trends and to a lesser extent the GEFS. Recent ECMWF runs already
hold systems well south of the Aleutians and remain more in line
with ECMWF ensembles through midweek. Accordingly, the WPC Alaskan
medium range product suite was mainly derived from the ECMWF
ensemble mean later week amid growing uncertainty, but favorable
model trends.

Schichtel

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 for the Alaska Panhandle Mon Apr 22.


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