Uitleg wetenschappelijke weersvoorspelling
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
1256 PM akdt Friday Oct 24 2014
models continue to perform well in the short range...however
considerable spread in both strength and position are apparent in
the Middle Range and the models become completely out of phase in
the Long Run. For the short term forecast leaned on a heavy blend
of GFS and nam12 and continuity. The 12z European model (ecmwf) does look considerably
like the 12z GFS and nam12 on low position and strength in the
Bering Sea Sunday and Monday as compared to the 00z run. Still
lots of spread between models and from run to run past 36 to 48
hours...leads to low confidence forecast past 48 hours.
Aloft...at 500 hpa...a 498 dam low continues to wobble around
eastern Siberia and spin off shortwaves to the east into the
Bering Sea and western and central interior. First shortwave
currently along a pawi to pafm to paga to pamc line will continue
to move east and weaken as it moves into the central and eastern
interior. Snowfall associated with this upper level trough is
expected to drop less than 1 inch as it moves into the central
interior. The next upper level trough...currently located along a
papo to paot to paun line will move into the western interior
tonight. Expect only scattered snow showers or flurries with this
trough. A stronger shortwave moves northeast out of western Bering
Sea and moves just west of St Lawrence Island Monday morning. The
upper level low wobbles around the Bering Strait as it weakens
through Tuesday of next week.
On the surface...a weak front over the western interior continues
to push to the east into the central interior this evening and
into the eastern interior Saturday morning. The front continues to
weaken with less than 1 inch of snow is expected. Scattered snow
showers associated with the weak trough currently over the West
Coast will diminish as it moves inland to isolated snow showers
A 995 mb low will move into the Bering Strait Saturday morning and
will bring another round of snow to western Alaska. Expect 2 to 4
inches of snow with around 4 inches expected in higher terrain of
the Seward Peninsula...Nulato Hills and western Brooks range.
Blowing snow is not expected to cause widespread reduction to
visibility...in addition rain may mix with snow south of the
Seward Peninsula winds limiting potential for blowing snow.
All eyes on next weather maker in the Bering Sea and along the
West Coast late Sunday and Monday. A 970 mb low moves northeast
into the central Bering Sea Sunday morning and will be located
approximately 250 nm southwest of St Lawrence Island Sunday
evening. Strong southwest winds ahead of the low will create high
surf along south and west facing coasts especially along the
Bering Strait coast where surge guidance is indicating around a 4
foot surge Sunday night and Monday morning. Significant snow is
expected Seward Peninsula and north with a snow and rain mix along
eastern Norton Sound and the lower yk Delta. Strong winds will
buffet the entire coast.
Coastal hazard potential days 3 and 4...none
heavy freezing spray warning for pkz235-pkz240-pkz245.
Small Craft Advisory for pkz200-pkz210-pkz220-pkz235.
Ccc Oct 14