Area Forecast Discussion
Issued by NWS Fairbanks, AK

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000
FXAK69 PAFG 251300
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
500 AM AKDT Sun Jun 25 2017

.DISCUSSION...
The 25/00Z 500 mb analysis large 505 dm low located in the High
Siberian Arctic centered near 79.6N 168.2E, or around 600 miles
north of Wrangel Island. A second upper low was located over the
western Bering around 400 miles northwest of Amchitka. Lastly a
552 dm low was located in the Gulf around 320 miles south
southwest of Yakutat. Short wave ridging was seen between the
latter two upper lows short wave ridging stretched from the tip of
the AK Peninsula through the YK Delta northwestward through St
Lawrence Island and into the Chukotsk Peninsula. A short wave was
rounding the crest of this ridge with the axis stretching from
Koyuk to Point Lay.

At the surface, low pressure was seen in relatively close
proximity to the associated upper level lows. A 984 mb low as over
the High Arctic located near 86N 159.5W. A NE-SW oriented cold
front stretched initially out ahead of this low and extended to
the southwest through the Beaufort Sea in the the Chukchi Sea,
remaining just offshore from the Northwest Arctic Coast. A 994 mb
low was seen over the Bering around 340 miles northwest of Adak.
A weaker 1011 mb low was located near the respective upper level
circulation, around 300 miles south of Yakutat. Surface ridging
stretched between the two lows from the north Pacific, with the
axis running along the 155W meridian northward through the western
third of the state.

Models for the 25/00Z run remain in fair to good agreement through
the upcoming week. The upper low in the Siberian Arctic will
continue to drift northward to the Pole. The aforementioned short
wave will continue to slide eastward through the Brooks Range
today and tonight, to eventually be cut off from large trough in
the arctic by Monday evening. A short wave rounding the Arctic
low will move through eastern Siberia today, to merge with upper
low in the western Bering to form broad troughing over the Bering
and Chukchi Sea by Monday, which looks to persist through the
upcoming week. This will in turn amplify the downstream ridge over
the central and eastern Interior from Monday through the upcoming
week, which will extend all the way to the North Slope as well.

At the surface, 984 mb low over the High Arctic will continue to
lift toward the pole, with the associated surface front rapidly
moving off to the northeast today. Weak high pressure over the
Interior will shift northeastward and will build over the eastern
Beaufort Sea as a 1016 mb low Monday night. The low pressure 340
miles northwest of Adak will remain relatively stationary over the
next several days in the central Bering Sea. Thermal troughing
will develop over the Interior again on Tuesday, and will shift
over the Brooks Range and North Slope for Wednesday.

North Slope: Strong winds over the western Arctic Coast will are
expected to diminish significantly this morning as the cold front
pushes inland. Some light rain will accompany this frontal
boundary here today, with little or no chance of rain east of
Barrow. Winds are expected to remain light until Monday evening
when high pressure redevelops over the eastern Beaufort Sea,
bringing a return to east winds to the Arctic Coast along with the
possibility of low fog and stratus. A return to a showery regime
is expected by Wednesday/Thursday as pieces of upper level energy
eject northward from cyclonic flow over the Bering Sea.

West Coast: Low stratus is expected to diminish over Norton Sound
later today as lower level winds turn offshore. A short wave and
associated surface front will lift northward from the low in the
western Bering this afternoon, bringing periods rain to St
Lawrence Island this afternoon, and showers to the Norton Sound
and YK Delta during the day Monday. Chances of rain will persist
through the week after the frontal passage as weak disturbances
rotate northward from the broad upper low in the Bering Sea.
Temperatures will diminish in the Chukchi Sea this morning as a
weather front over the western Arctic Coast moves inland.
Southeast winds will increase over the Bering Sea and Kotzebue
Sound Monday with the approach of the second weather front from
the south. Temperatures will range from the 40s near Kivalina and
Point Hope to the 50s and lower 60s for point south.

Interior: Surface ridge of high pressure will bring fair weather
to the western Interior today. Short wave trough moving through
the Interior combined with moist westerly flow will bring
scattered showers and isolated thunderstorms to the southern
Interior and Alaska Range during the afternoon and evening hours.
Showers will be possible for the eastern Brooks Range this
afternoon/evening as well. For Monday the ridge axis aloft will
be over the central Interior, keeping convection limited for the
eastern Interior and eastern Alaska Range Monday
afternoon/evening. Thermal troughing looks to resume for the
Interior Tuesday with a chance of showers for most of the Interior
along with isolated thunderstorms for zones 208, 209, 217, 219,
220 and 224. Chances of rain will persist through the week for the
west Interior as weak disturbances rotate northward from the
broad upper low in the Bering Sea.

Coastal Hazard Potential Days 3 and 4...None.

&&

.FIRE WEATHER...The driest and warmest combined conditions will be
focused over the northeast Interior in the Yukon Flats and
southeast Brooks Range again today with highs 65 to 75 and min RH
readings between 20 to 25 percent. Convection for this afternoon
and evening will be focused generally along and southeast of a
line from Circle to Minchumina. Overall warmer and drier conditons
are expected tomorrow for the Interior as upper level ridge aloft
moves into the area. Convection for tomorrow looks to remain
limited to the far east Interior and eastern Alaska Range. Thermal
troughing looks to resume for the Interior Tuesday with a chance
of showers for most of the Interior along with isolated
thunderstorms for zones 208, 209, 217, 219, 220 and 224. Chances
of rain and higher humidity is expected from Tuesday through the
rest of this week for the west Interior as weak disturbances
rotate northward from the broad upper low in the Bering Sea.


&&

.HYDROLOGY...Flood Advisory remains in effect this morning for
AK Range small streams or creeks from Dot lake to Tanacross due
to rainfall amounts of 2 to 3 inches falling in that area
yesterday. These drainages are experiencing bankfull conditions
along with areas of minor flooding based on a spotter report
yesterday evening. Conditons will gradually improve here today,
but lager rivers in the area, including the Tanana are expected to
rise over the next one to two days.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory for PKZ210-PKZ220-PKZ225-PKZ230.
&&

$$

NTS JUN 17



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