485
FXAK69 PAFG 020039
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
439 PM AKDT Wed May 1 2024

.SYNOPSIS...

Models are in good agreement at least through Thursday showing
the upper trough over the Bearing Sea moving eastward towards the
Alaska Peninsula and eventually into the Gulf of Alaska by
Thursday afternoon. We will see increased southerly flow through
the Alaska Range that will bring Chinook winds that will lead to
some elevated fire weather concerns on Friday and continuing into
the weekend. This southerly flow will actually be reinforced by
another strong upper-level trough that moves through the Bering
Sea and into the Alaska Peninsula into the weekend.

&&

.DISCUSSION...

Frontal boundary moved through the Interior and now will see
a slow warm up in temps, warming back up into the 60s Friday
and Saturday. We will see some increasing Chinook winds along the
northern slopes of the Alaska Range. Because of this, wind prone
areas will see wind gusts increasing to around 30 to 50 mph,
especially into the weekend. With lower daytime humidity values,
this will lead to some elevated fire weather conditions from
Thursday and only increasing into the weekend. This will also
allow for some sort of WAA for the interior that will bring above
average high temperatures.

An Arctic cold front will generally continue to impact the North
Slope through late week. This will lead to cooler than normal
temperatures across the northern slope into the weekend. We will
also see periods of light snow, fog, and low stratus through at
least Friday. Winds will begin to increase as we head into the
weekend, with gusts up to around 30 mph that will likely bring more
periods of blowing snow.

West coast...Precip on the downtrend for Thursday before the
second upper-level trough moves into the Gulf of Alaska that will
bring another round of what looks to be more widespread showers to
the southern West Coast on Friday and into Saturday. Northerly
winds will ramp up in the Bering strait with gale-force winds
Thurs into Friday.

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

&&

.FIRE WEATHER...
By Thursday, min RH values from Fairbanks into the Delta Junction
and the Eastern Alaska Range and the Upper Tanana Valley will be
in the 15 to 30 percent range. Mixing this with increasing
southerly winds through the Alaska Range passes fire weather
concerns will increase. Looks like moderate Chinook winds will
develop as early as Thursday afternoon, increasing as we move into
Friday and then continuing into the weekend. Wind gusts of 25 to
40 mph near Delta Junction and higher gusts near Isabel Pass and
lower humidity values will be very near Red Flag conditions for
the aforementioned areas.

&&

.HYDROLOGY...

An ice jam has formed 6 miles downstream of Manley and is causing
minor flooding at the community park along the slough. As of
midday Wednesday, the River Watch team reports that this jam does
not appear to be strong.

However, ice is still in place and looks strong at the jam point
which caused flooding in 2022. It is possible that when the jam
just down stream of Manley breaks, that it will form back up near
the 2022 location, but the flooding should not become much worse
than it is currently. When the jam finally releases and ice
flushes further down stream, river levels are expected to come
back down in the Manley area.

River Watch flew the Yukon River yesterday from Eagle to
FourtyMile River. An observer 23 miles upstream of Eagle said that
the Yukon there broke up yesterday afternoon. Ice began flowing
but within a few hours had stopped flowing and an ice jam formed.
Yukon rose to near mid-summer high levels and was continuing to
rise slowly. Due to current river levels and ice conditions, the
threat for flooding has diminished in the area around Eagle.
However, ice jams can still pose a localized threat in the areas
immediately around where they form.


&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Flood Watch for AKZ846.
PK...Small Craft Advisory for PKZ806.
     Heavy Freezing Spray Warning for PKZ806-816.
     Brisk Wind Advisory for PKZ807-810-811-856-857.
     Gale Warning for PKZ816.
     Gale Warning for PKZ817.
     Gale Warning for PKZ851.
     Gale Warning for PKZ854.
&&

$$