Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
127 am akdt Friday Jul 29 2016
forecast remains focused on widespread heavy rain event over
western Alaska as well as the interior. The 00z model suite
initialized well against the 00z analysis and verified well
against the 06z analysis. Models spread has increased some through
the short range and mid term over yesterdays model runs but
remains steadfast in bringing significant rains over much of the
West Coast south of the Seward Peninsula and through the interior
with the heaviest rains Fairbanks and south. Model spread has also
increased in the long range but remains reasonable.
Aloft at 500 hpa, a 520 dm low located 200 nm north of Barrow will
continue to drift slowly north and east as a strong shortwave
dives south to near the northwest coast this morning and will
sweep southeast over the Brooks range this evening. A deep layer
of moisture from surface to near 500 hpa continues to move to the
east just south of the Seward Peninsula this morning and will
move over the western and central interior today. Persistent
moist westerly flow over the West Coast and interior will persist
through Saturday as strong cyclonic flow around the upper level
low to the north of Barrow continues into Sunday.
West Coast and western interior...rain continues to move inland
and into the western interior. Models continue to indicate nearly
2 inches of rainfall in a band from Nome eastward into the Nulato
Hills tapering to one and a half inches near Galena through
Saturday morning with an additional half inch possible Sunday.
Central and eastern interior...heavy rain showers with a front
that pushed through the central interior Thursday evening has
dropped between a quarter to over 1 inch locally over the chena
river basin. Next round of rains continues to move into the
central interior and will become heavy at times later this morning
in and near Fairbanks. Rainfall totals through Saturday morning
are expected to range from 1 to 1 and a half inches over much of
the central interior from Fairbanks south with locally 2 inches
over the western Alaska Range. An additional one half inch to
three quarters of an inch is expected Sunday.
North Slope and Arctic coast...a cool and unsettled pattern
will continue with 850 mb temperatures near 4 below near Barrow
this morning will cool to 6 below by Sunday. Rain showers will mix
with snow in the Brooks range tonight and Saturday with several
inches of snow accumulation expected above 3500 feet.
Coastal hazard potential days 3 and 4... 20 to 30 kt southwest
flow will create elevated surf today through Saturday along south
and west facing coastlines in Norton Sound. Current gauges
indicate between a half foot to one foot storm surge above normal
tides. A 1 to 3 foot storm surge above normal tides can be
expected in eastern Norton Sound through Saturday. Those with
interests or with personal property along the coast in Norton
Sound and along the Yukon Delta should move items above high water
Fire weather... widespread wetting rains over the West Coast,
the western interior as well as the central interior will limit
fire weather concerns through the weekend.
storm total quantitative precipitation forecast through Saturday continues to indicate between 1
and 2 inches in a broad swath from Nome to Fairbanks and south to
the Alaska Range. Deep layer moisture from the surface to 500 mb
will continue to sweep east on moderate west to southwest flow.
West and southwest facing terrain will receive additional rainfall
with enhanced upslope flow. The Nulato hill along with the western
Alaska Range and higher terrain east of Fairbanks appear to be in
the crosshairs for the heaviest precipitation. Flood watches
remain in effect for zones 210, 211, 212 and 216. Will need to
closely monitor rivers and streams in these zones as well as the
middle Tanana Valley where soils remain soaked and rivers continue
to run high from rain events earlier this week. River S and
streams will likely respond quickly with additional rainfall.
Flood Advisory continues for the chena river upstream of nordale
Road near Fairbanks with operations continuing on the Moose Creek
dam. See latest Flood Advisory statement for additional details.
Flood Watch for akz210-akz211-akz212-akz216.
Small Craft Advisory for pkz200-pkz210.
Ccc Jul 16