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000 
FXAK69 PAFG 162351
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
351 PM AKDT Tue Jul 16 2019

.SYNOPSIS...
Highlights are:
Temperatures and humidity will see little change through Thu, then
cooling temps and rising RH on Fri and into the weekend. Isolated
to widely scattered thunderstorms across all of Interior Alaska
and the Seward Peninsula today, will decrease from the west to be
over the Central and Eastern Interior on Wed, over the southeast
Interior Thu, and then just southeast of Tok on Fri. Expect
between 0.10 and 0.50 inch of rain across most of the Southern
Interior and Brooks Range through Thu, while the northern Interior
remains mainly dry through Thu. Smoke has thinned in most areas, 
but expect it to get thicker over the Northern Interior over the 
next few days, especially near Chalkytsik where conditions will 
remain mainly dry. 

Aloft...
A weak ridge over the Northern Interior of Alaska will persist
through Wed, then build over the southern Interior and South
Central Alaska Thu and Fri, then rebuild over the Interior early
next week. Conditions will remain near seasonal temperatures 
through Thu, then cool and become wetter on Fri and Sat, before 
warming again next week.

A weak short wave trough from the YK Delta to Arctic Village will
weaken in place tonight. There are isolated to widely scattered 
thunderstorms along much of this trough now that will diminish 
tonight. 

A second weak short wave from Delta Junction to Eagle will move 
to McGrath to Fairbanks by 4am Wed, then move south. This has a
band of showers and isolated to widely scattered embedded
thunderstorms associated with it. Widely scattered thunderstorms 
will develop southeast of the trough this evening. The areas of 
widely scattered thunderstorms across the southern and Central 
Interior will have gusty winds, brief heavy rain, and small hail 
associated with them. 

A third short wave now over the southern Yukon Territory will 
move to Delta Junction to Eagle by 4pm Wed, then to Delta Junction
to Old Crow by 4am Thu. This will cause isolated to widely 
scattered thunderstorms along this trough as well. 

Surface...
A 993 mb low 80 NM north of Utqiagvik will move to 120 NM north of
Barter Island as as 995 mb low by 4am Wed, then move to 150 NM
northeast of Barter Island as a 1000 MB low by 4pm Wed, then
continue east. A cold front stretching west from this low will
move to Nuiqsut to Point Hope by 4am Wed, to Barter Island to
Kivalina by 4pm Wed, then weaken. Expect rain and fog along the 
front and West winds 10-20 kt. Winds and rain will diminish West 
of the front. 

A second and much stronger cold front will move to the Eastern 
Chukchi Sea by 4am Thu, to just east of Pt Barrow to Point Hope 
by 4pm Thu, to Nuiqsut to the Bering Strait by 4am Fri, and to 
Demarcation Point to Arctic Village to Norton Sound by 4pm Fri. 
Expect rain and fog and West winds 15-25kt along the front, and 
temperatures to fall about 10F behind the front. 

A thermal trough stretching from Bethel to Arctic Village will
move to McGrath to Arctic Village by 4pm Wed, to Northway to
Arctic Village by 4pm Thu, then dissipate along the Alcan Border 
Fri. Will see West winds increase to 10 mph along the trough Wed
and Thu. 

&&

.DISCUSSION...
Models all initialize about 10m too low on h500 heights over 
Northern AK at 12Z. Models show similar solutions through Thu, 
but after that the NAM is much deeper than the GFS and ECMF with a
short wave moving over the West Coast and Northern Interior on 
Fri. Since models initialize the strength of the Ridge over 
Alaska too weak, we do not favor the deeper NAM with this feature 
on Fri. GFS solution is midway between the NAM and ECMF on the 
strength of this feature and is the favored solution at this time
for Fri.

Models differ on areal coverage. We prefer the broader areal
coverage shown by the GFS and ECMF and using a blend of them.

At the surface at 15Z, all models verify 3 mb too weak on the low
just north of Utqiagvik. Expect this feature to remain 3 mb 
deeper through 4am Wed, and as a result expect winds in the 
vicinity of the low be 3-5kt stronger than models indicate over 
the Arctic Coast through tonight. 


Coastal Hazard Potential Days 3 and 4...
Slightly elevated surf along the coast Fri and Sat. Much
uncertainty on where this might occur and how strong, but will not
be major event. 

&&

.FIRE WEATHER...
Temperatures and humidity will see little change through Thu with
highs 70 to 80, and RH 25 to 45 with the warmest temps and driest
conditions today and Wed in the Northern Interior. Expect cooling
temps and rising RH on Fri and into the weekend. Isolated
thunderstorms across the Interior and Seward Peninsula today 
with widely scattered thunderstorms in the southern Interior 
today. Wed, expect Isolated PM thunderstorms in Central and 
Eastern Interior with widely scattered PM thunderstorms in zones 
220 221 222 223 and north slopes of 225 and 226. Thu expect 
isolated thunderstorms Southeast of Denali to Old Crow. Fri 
isolated thunderstorms southeast of Tok. 

Expect between 0.10 and 0.50 inch of rain across most of the 
Southern Interior and Brooks Range through Thu, while the northern
Interior remains mainly dry through Thu. Smoke has thinned most 
areas, but expect it to get thicker over the Northern Interior 
over the next few days, especially near Chalkytsik where 
conditions will remain mainly dry. 

&&

.HYDROLOGY...
Freezing levels near 8000 ft and remaining steady through Thu, 
then beginning to fall. Expect glacial fed rivers to remain at 
current high levels through Fri, then begin to fall slowly. Clear 
rivers and streams will remain at or below normal levels. 

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
None.

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