Area Forecast Discussion
Issued by NWS Fairbanks, AK
FXAK69 PAFG 241218
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
418 AM AKDT TUE MAY 24 2016
MODELS...Excellent agreement through Friday, beyond that solutions
are all over. Latest and previous runs initialized well against
the 06Z surface analysis. Moving to westerly flow the next couple
days and that will put the west coast and interior Alaska in a
much wetter regime for mid week. Will use an equal blend of the
models for the most part. For precipitation will lean a little
more toward the NAM to enhance the more likely areas.
ALOFT...AT 500 HPA...A 526 hpa low over the siberian coast
persists through mid week, but will slowly move to the west and
weaken. A shortwave swinging around the low moved through the
interior forecast area earlier, and another is moving across the
western zones and will move through the central and eastern
interior later this afternoon. As the flow aloft becomes more
westerly late Tuesday it will allow a series of shortwaves to move
east across the state. Early Wednesday a 575 dam high will develop
south of Dutch Harbor and continues north over Bristol Bay by
Thursday morning as it cuts off the westerly flow across the
state, and over the lower Yukon delta by Friday morning. Ridging
over the eastern arctic and Beaufort sea will weaken as the high
in the arctic moves north. At 850 HPA...Zero isotherm lies from
Old Crow to Tok to Anchorage to Cape Romanzof and west this
morning, and will stay primarily south of the area through
Wednesday before it starts moving north, and will lie from Dawson
Yukon to Delta Junction to Nikolai to the Bering Strait by
Thursday morning. It will continue to push north through Friday
and will lie over the Brooks Range through the weekend.
SURFACE...Stationary front lies over the Brooks range this morning
with ridging over the high arctic associated with a 1024 mb high
600 nm north of Barrow. High pressure persists south of the
Brooks Range with a 1018 mb high over the middle Yukon valley
associated with a 1029 mb high in the northeast Pacific just south
of Kodiak Island. The front will slide south a bit as the
shortwaves aloft move across the state Wednesday and Thursday.
Ridging will build over Bristol Bay by Wednesday evening with a
1028 mb High center. The High will continue north over Norton
Sound by Thursday afternoon then merges with the ridging over the
arctic resulting in a 1027 mb center over St Lawrence island and a
1031 mb center 250 nm north of Barrow. As the front weakens and
dissipates Thermal low will develop over the upper Tanana valley
late Friday and Saturday.
ARCTIC COAST AND BROOKS RANGE...The GOES visible imagery at
24/0800Z shows a pretty good patch of stratus moving over the
eastern arctic coast and this is verified by the observations in
the area as 200 foot ceilings and 1/4 mile visibility or less fog
is being reported at several locations. The GOES MVFR/IFR products
at 24/0800Z indicate the lowest ceilings and visibility are in a
small patch of stratus moving to the west in the low level flow.
Will need to watch the stratus to see if it stalls or keeps
moving. Expect it will make Atqasuk, but the flow to the west of
there is from the south so it will be pushed back offshore, or
just stall. The flow at Barrow doesn`t change to south until early
Wednesday, so they could be stuck in the low stuff until then.
With the stationary front hanging around expect some periods of
precipitation in various forms from rain to snow, with a chance of
freezing rain as well. Temperatures along the coast mainly in the
30s with temperatures in the Brooks range and inland plains in
the 40s during the day and 20s at night.
WEST COAST AND WESTERN INTERIOR...West flow will persist into late
Thursday. At the surface southwest flow will persist into Thursday
then shuts off as the high moves over Norton Sound and the flow
becomes light and variable. Good moisture feed from the west
mainly south of the Bering Strait will kick in later this evening
with showers developing and persisting into Wednesday before the
ridging to the south start pushing the precipitation to the north.
Most areas will see between 1/4 and 3/4 of an inch or rain through
Thursday with higher amounts of around an inch possible in the
Nulato hills and the south slopes of the Brooks Range. Cloudy,
damp, and cool conditions will prevail.
CENTRAL AND EASTERN INTERIOR...Expect a few showers today with
only a slight chance of thunderstorms as an upper level shortwave
moves through the area this afternoon and early evening. With the
westerly flow taking over at mid levels that will suppress
thunderstorm activity across the state Wednesday and Thursday,
however, there is be plenty of rain or showers to go around with
most areas getting around 1/2 inch of rain by Friday. Expect
slightly below normal temperatures through the week with the
cloudy and damp conditions. Winds will generally be light from the
west to southwest through Thursday.
.FIRE WEATHER...Will be pretty quiet this week. Not expecting much
Thunderstorm activity if any through Saturday and cloudy and
cooler conditions with rain will prevail in the mid week.
.HYDROLOGY...No changes expected, Flood Advisory continues for the
Kuparuk river and Flood Watch continues for the Colville river
delta. Expect some heavier precipitation during midweek with up to
1 inch of rain in the Brooks range, and that could significantly
impact those areas this next weekend and next week if river
conditions do not improve.
Flood Advisory for AKZ203.
Flood Watch for AKZ203.
SDB MAY 16