816
FXAK69 PAFG 182124
AFDAFG
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
124 PM AKDT Thu Apr 18 2024
.SYNOPSIS...
Satellite imagery this afternoon shows an upper low over eastern
Russia, while upper riding continues to expand across Interior
Alaska. Mid and upper level moisture and a weak upper disturbance
has led to widespread cloud cover across much of Alaska. Dry air
over western Canada should progress northeast over the next couple
of days. Coastal snow and inland rain will continue through
tonight, dissipating on Friday as the eastern Russia low lifts to
the northeast. Northeasterly flow along the North Slope will keep
temperatures cold, with fog and snow. Overall, models are in
decent agreement through the weekend, with high pressure
dominating across much of Alaska. By early to mid next week,
unsettled weather looks to return to the West Coast, however,
models and ensembles vary in timing and precipitation amounts.
&&
.DISCUSSION...
Upper level ridging across Interior Alaska will expand and strengthen
through the weekend. 500 mb heights look to exceed 565 dam on
Friday. Drier air from western Canada will also fill in across
Interior Alaska as the weak embedded energy responsible for the
current cloud cover lifts to our north. This should allow for
clearing conditions on Friday. Temperatures will remain warm
through the weekend, with 40s to even a few lower 60s in the lee
of the Alaska Range. Chinook winds will continue into this evening
along the lee slopes of the Alaska Range, where wind gusts of 40
to 50 mph will remain possible. These winds will decrease
overnight as the gradient relaxes and upper ridging builds
overhead. As we move late into the weekend and early next week,
the upper ridge will begin to break down. Temperatures look to
cool slightly as upper heights fall. Highs early next week will
range from the lower 40s into the mid 50s. Overall, precipitation
chances look low, with expanding potential over the interior
western zones.
Precipitation looks to continue along the West Coast through
Friday morning, decreasing tomorrow afternoon as the upper ridge
expands across the region, and the upper low to the west lifts to
the northeast. Light snow along the coast, and interior rain will
continue overnight, with near steady temperatures in the upper
20s to lower 30s. Additional snow amounts will remain at less than
an inch. Temperatures will then warm through the weekend into
early next week with mid 30s to lower 40s. The next upper storm
system looks to take shape in the Tuesday to Thursday time frame.
There are model differences, with the strength of an upper
disturbance lifting north along the West Coast. The GFS and ECMWF
both have an upper system, with the ECMWF on the stronger side,
with more widespread western Alaska precipitation. The GFS is much
weaker, with less precipitation. Attention then turns to a
frontal boundary sometime Wednesday into Thursday, with better
chances for precipitation and gusty winds. However, there is a lot
of uncertainty with timing.
Areas along the North Slope will continue to see low stratus, fog
and periods of light snowfall through the next several days.
Northeasterly flow will also continue, briefly turning
northwesterly as the eastern Russia upper system ejects to the
north. Flow will then return to northeasterly for early next week.
This will help keep temperatures in the teens to 20s, with
continued fog and periods of light snowfall.
Coastal Hazard Potential Days 3 and 4...None.
&&
.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Wind Advisory for AKZ847-849.
Wind Advisory for AKZ837.
PK...Brisk Wind Advisory for PKZ801-802-850-857-858.
Brisk Wind Advisory for PKZ812-813.
Brisk Wind Advisory for PKZ814.
Brisk Wind Advisory for PKZ815.
Brisk Wind Advisory for PKZ859.
Brisk Wind Advisory for PKZ860.
Brisk Wind Advisory for PKZ861.
&&
$$
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