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Northern Alaska forecast discussion 
National Weather Service Fairbanks Alaska
211 PM akdt Wednesday Aug 27 2014


Models...good agreement even through the Middle Range with the
latest runs. Still showing some differences in the speed of the
shortwaves as they move through the flow. Will use a blend of the
models for the short term. There is even some concensus in the
extended periods with the models maintaining the low as it
oscillates around the Arctic with ridging over the Pacific and
a rather fast...and active...westerly flow across the state.

Aloft...at 500 hpa...deep cyclonic flow over the high Arctic will
slowly work south into the weekend. A shortwave over the eastern
Brooks range will exit the area to the northeast and dissipate
this evening. A 547 dam low over Bristol Bay will move southeast
over the southern Gulf of Alaska by Thursday morning...then
northeast to 200nm south of Yakutat by Friday morning. A 510 dam
low over 77n 180 will drift southeast to 76n 170w by Friday
morning as the associated shortwave moves to lie over 168w and
over the Bering Strait. The low continue southeast to 74n 163w by
Friday morning as the shortwave moves to lie from over Barrow to
Indian Mountain to Kenai. As the low continue to drop south the
shortwave will continue to move east to over the alcan border by
Saturday morning. A second shortwave will spin off the low Friday
night and move over the Bering Strait by Saturday morning. At 850
hpa...zero isotherm is approaching the northwest coast this
evening as the front moves southeast. Zero isotherm will lie from
deadhorse to Ambler to Nome to south of the Gulf of Anadyr by middle
day Thursday...then from barter to Manley Hot Springs to
Sleetmute to St Matthew island by Friday morning. Then moves to
cover most of the forecast area from the Alaska Range north by
Saturday morning.

Surface...weak ridging from the southeast over the central
interior will be pushed south as a 1000mb low in Bristol Bay
moves east into the GU f of Alaska. A 995mb low associated with a
frontal system moving over the northwest coast this afternoon and
evening will move to near 77n 152w by Thursday morning as the
front moves to lie from kuparik to Anaktuvuk Pass to Shaktoolik
to St Matthew island by Thursday morning. The front will lie from
MacKenzie Bay to Beaver to Nunivak Island by late Thursday as it
weakens and is pulled east into Canada. A series of lows will
develop on the front as it moves over the upper Yukon Flats. A
1013mb high will develop in the Lee of the front and move over
the eastern Bering Sea by Friday morning. The low in the high
Arctic will strengthen as the next shortwave aloft approaches the
northwest coast and a frontal system will move to the West Coast
by Saturday morning.

Arctic coast...a really mixed bag of stuff going on. As the front
moves through winds will increase to 15 to 30 miles per hour for a short
duration...then taper down to 10 to 20 miles per hour as they become west to
northwest behind the front. Good cold air advection will bring
temperatures down...especially inland areas. Temperatures will
fall on the coast but will be moderated by the open water along
the coast. Look for a mixed bag of precipitation as well. 2 to 4
inches of snow in the Brooks range above 1500 feet over the next
48 hours...while most areas will see some snow fall it will not
stick at the lower elevations this time around.

West Coast and western interior...front moving over the northern
Seward Peninsula and Bering Strait now...so look for cooler
temperatures as 500 hpa heights fall to around 545 hpa. A period
of rain showers will accompany the front...but no snow expected
this far south. Cold air advection behind the front will push
temperatures down over the next several days. Winds kicking up as
the front moves through so expect 15 to 25 miles per hour from the Bering
Strait north tonight...except up to 35 miles per hour near Point Hope. Winds
will diminish Thursday.

Interior...some clearing this evening...but ridge is pretty dirty
so not going to clear out to much. As the front approaches from
the west Thursday it gets some help as moisture swings up out of
the Gulf as that low moves to south of Yakutat. Expect showers to
begin in the evening Thursday and continue into Friday evening
before tapering off over most of the area by midnight. Winds
generally light across the area...but may kick up to 10 to 20 miles per hour
along the front for a while north of Fairbanks. Good cold air
advection with the system will push temperatures down beginning
Friday. Lows in the 20s from the White Mountains north and 30s to
the south. Of course some of the traditional cold spots around
Fairbanks will most likely be in the 20s for lows. Expect some
areas of fog in the morning clearing by around noon.

Coastal hazard potential days 3 and 4...persistent northwest winds
and waves over the northwest coast...but not strong enough to be
an issue at this time.


Fire weather...with next system expected to bring wetting rains
and cooler temperatures there continue to be no concerns.


Hydrology...some heavy snow in the Brooks range next 48
hours...but not expecting it to melt off rapidly and make it into
the streams and rivers...so no concerns at this time.


Afg watches/warnings/advisories...

Small Craft Advisory for pkz225-pkz230.



Sdb Aug 14

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