Small Craft Advisory 33, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
328 AM AKDT Fri May 10 2019

.HIGHLIGHTS...
A strong weather front will move north of the Alaska Range this
afternoon and push north and west to the West Coast and North
Slope by Saturday afternoon. This storm will bring strong southerly
chinook winds across the Alaska Range from this afternoon through
Saturday afternoon, causing Red Flag conditions near Delta
Junction this afternoon through Saturday evening. This storm will
bring rain to much of the Western and Northern Interior of Alaska
this afternoon and tonight and will and spread rain to the West
Coast tonight and Saturday, and will bring a chance of snow and
rain to the North Slope on tonight and Saturday.

.SYNOPSIS...
Aloft at 500 mb...A deep longwave trough extending from the North
Pole to the Bering Strait and southward to the Central Aleutians
and Central Pacific will remain in place as an upper level ridge
continues to build north over British Columbia, the Yukon and the
Central and Eastern Interior today but will be pushed to the east
over the weekend allowing for the deep trough over the Bering Sea
to expand east over the Central and Eastern Interior. A series of
shortwaves will push north over northern Alaska into early next
week before the upper level ridge over the Yukon pushes back to
the west over Central Alaska which will bring seasonal
temperatures and generally dry conditions over the Central and
Eastern Alaska and showery conditions over western Alaska by the
middle of next week.

On the surface...A 985 mb low currently over Kodiak Island will
continue to push north and west into southwest Alaska this evening
and will push a strong front north and west over the Alaska Range
this evening. Strong winds are expected to develop in and near the
Central and Eastern Alaska Range Passes as well as along the
northern foothills of the Alaska Range. Wind Advisories have been
issued for these areas beginning this afternoon and continuing
through Saturday evening. A strong mountain wave combined with 60
knots aloft will produce strong winds and wind gusts in these
areas. The strong and gusty winds will be concurrent with minimum
relative humidity levels dropping into the 20s this afternoon and
evening south of Delta Junction and north of Black Rapids. The
relative humidity is expected to only recover to around 50 percent
tonight and will drop again into the 25 to 30 percent range
Saturday afternoon and evening. The Fire Weather Watches for these
areas have been updated to Red Flag Warnings beginning this
afternoon and continuing through early Saturday evening. North of
Delta Junction neither winds nor temperature requirements will be
met for Red Flag conditions but relative humidity levels in the
20s are expected especially east of Fairbanks.

There is just enough energy available in the atmosphere and
instability to produce some isolated thunderstorms in the interior
this afternoon along a line from McGrath to just north of
Fairbanks to Chicken however strong winds aloft will likely
quickly shear apart any storms that do manage to start so the
storms that do develop will be short lived.

Storm total precipitation through Saturday is expected to range
from one tenth to a quarter of an inch in the Western and Northern
Interior. Several inches of snow are expected above 2500 feet in
the Brooks Range as the front pushes north tonight.

The 10/00z model suite initialized well against the 00z surface
analysis and verified well against the 06z surface analysis. Model
spread has been reasonable on the position and strength of
synoptic scale features and remains consistent from model run to
model run.

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

&&

.FIRE WEATHER...
Strong southerly chinook winds will develop this afternoon along
the north side of the Alaska Range through Saturday afternoon.
South winds of 25 to 35 mph with gusts to 55 mph are possible near
Delta Junctions with wind gusts to 60 mph possible further south
through Isabell Pass. Minimum RHs are expected to fall into the
20-30% range this afternoon and in the 25% to 30% range on
Saturday afternoon in the southern interior including the Tanana
Valley. Neither winds nor temperatures are expected to meet Red
Flag criteria in this areas, however expected very windy
conditions and dry conditions have prompted upgrading the Fire
Weather Watches near and just south of Delta Junction to Red Flag
Warning beginning this afternoon and continuing into Saturday
evening.

This same storm system will bring rain to much of the Western and
Northern Interior of Alaska this afternoon into Saturday. There
will be a slight change of thunderstorms each afternoon and
evening along a line from McGrath to just north of Fairbanks to
Chicken.

&&

.HYDROLOGY...
With increased temperatures and freezing levels Fri, should see
increased melting into the weekend, but more significant melting
next week. Rivers rising slightly through this weekend, then
bigger rises next week. Expect slow melting of in place ice to
continue through the weekend. May get enough melt water next week
for break up to get under way remainder of northern AK.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Wind Advisory for AKZ223-AKZ225-AKZ226.

Red Flag Warning for AKZ223-AKZ226.

Small Craft Advisory for PKZ200-PKZ210-PKZ220-PKZ225.

Brisk Wind Advisory for PKZ240-PKZ245.
&&

CCC MAY 19