Scientific Forecaster Discussion
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Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
124 am akdt Mon may 29 2017
the 00z model suite initialized well against the 00z surface
analysis and verified well against the 06z surface analysis.
Model spread remains minimal through the middle of this week on
system position and strength however there remains significant
differences in 850 mb temperatures over the eastern half of the
the state by mid week. The differences in temperatures aloft will
impact both surface temperatures and stability and chances for
showers and thunderstorms later in the week over the central and
eastern portions of the interior where fire weather concerns will
likely be the focus of concern.
Aloft at 500 hpa, a 535 dam upper level low over Bristol Bay will
move north to merge with a weakening upper level low over the
southern Chukchi Sea and West Coast of the North Slope tonight.
Upper level lift combined with a weak trough over the western
interior will combine to produce a swath of rain over the western
interior from near Holy Cross north to near Ambler. One quarter to
one half of an inch of rain is expected to fall over the next 24
hours with local amounts reaching three quarters of an inch. Main
Stem rivers remain a low stage so no significant Hydro issues are
expected with the inbound rain. An upper level ridge will briefly
retreat to the east over the Yukon as the upper level low over
western Alaska moves to the north and will then move back to the
west over the eastern interior Tuesday and the central interior
Eastern and central interior temperatures will continue to climb
with temperatures reaching the lower 70s by mid week. As the
gradient between the upper level ridge and low increases today a
trough over the southern interior will increase in strength. Winds
will increase again this afternoon along the northern slopes of
the Alaska Range especially near Alaska Range passes. Near red
flag conditions are expected in these areas. See fire weather
sections for more details.
Western interior can expect isolated thunderstorms today along a
line from the lower yk Delta northeast to McGrath, Galena, Bettles
and Arctic Village. Numerous showers and expected over much of
the West Coast and western interior as the upper level low moves
to the north.
Tranquil weather is expected over the West Coast and North Slope.
Partly cloudy skies over the western CAPES will continue into
Tuesday while the mostly clear conditions on the North Slope will
give way to low ceilings, for and drizzle tonight and will
continue through tomorrow.
fire weather concerns will increase this week as temperatures
rise, and fuels dry under the influence of wind, warm, and mostly
sunny conditions. The main area of concern today will be along
the north slopes of the eastern Alaska Range, particularly along
the Richardson Highway from Isabel Pass north to Delta Junction.
Minimum relative humidity values are expected to drop into the 20s this
afternoon. Sustained winds are expected to top out around 25 mph
with gusts to around 40 mph through this evening, with the
strongest winds expected late this afternoon. Will need to
closely monitor today as meteorological conditions locally flirt
with red flag conditions. Meteorological conditions will be
similar along the Parks Highway north of McKinley Park flirting
with meteorological red flag conditions today, but fuels are not
dry at this time to for red flag concerns.
Winds will be lower, but breezy over the rest of the interior
with minimum relative humidity values in the 20 to 30 percent range, however
temperatures today and Tuesday will not reach red flag criteria
and are not likely to meet red flag criteria for wind other that
locally for a brief period of time. Temperatures will gradually
warm with daytime highs in the lower to mid 70s by the middle of
the week. Fuels will continue to dry and will need to closely
monitor through the week as we transition from a cool and wet
pattern to a warm and dry pattern.
24 hour rainfall totals in the one quarter to one half inch range
with isolated amounts up to three quarters of an inch are
expected over the western interior extending north to the south
faces of the Brooks range today and tonight. Main Stem river level
are low so no Hydro issues are expected with this rainfall.
brisk Wind Advisory for pkz240-pkz245.