Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Northern Alaska forecast discussion 
National Weather Service Fairbanks Alaska
546 am akdt Sat Aug 1 2015

Synopsis...
aloft...
a long wave trough over eastern Alaska and northwest Canada will progress
east into western Canada sun. A long wave ridge over the Bering
Sea will build over western Alaska Sat...and over the eastern
interior sun then persist through Tuesday. The ridge will retreat
slowly west from Wednesday through next weekend. This pattern will cause
a warming and drying trend south of the Brooks range sun through
Tuesday...then a cooling and moistening trend from Wednesday through next
weekend. The North Slope will remain in westerly flow so will see
periods of rain with temperatures near normal.

A weak short wave trough from Eagle to Delta Junction will move to
Mayo to Northway by 4pm Sat then weaken. There are isolated
showers with this now with this trough and expect isolated
thunderstorms southeast of the trough in the afternoon.

A strong second short wave trough from Prudhoe Bay to Point Hope
will move to Old Crow to Tanana to St Marys by 4pm Sat...and to
Eagle to Tok by 4am sun...then east of Northway by 4pm sun.
Widespread showers now occuring along this trough becoming
scattered this afternoon as the trough moves southeast across the
interior.

Weak instability in the extreme southeast interior will remain through
this afternoon.

Surface...
a 1002 mb low 300 nm north of Prudhoe Bay will move to 500 nm
north of Demarcation Point by 4pm Sat and then slowly weaken in
place. A cold front from this low to Prudhoe Bay to Point Hope
will move to Arctic Village to Kivalina by 4pm Sat...and then
weaken. There is rain just ahead of the cold front with .25-.50
inch in northwest Alaska by afternoon. Rain will change to scattered
showers as the front moves southeast across the interior today.
Southwest winds 15g25kt with the front over the Arctic coast will
turn northwest and decrease behind the front. Will see winds west 10g20kt
ahead of the front over the northern interior today into this
evening. This will push smoke from western and central interior
fires into the eastern interior today and tonight.

A second low in Siberia will move to near wrangel island on sun
and then move east across the Chukchi Sea to 200 nm northwest of
Barrow by 4pm Monday as a 1003 mb low. This will push the previously
mentioned cold front north as a warm front over the western Arctic
coast sun and over the eastern Arctic coast Monday night. Expect
another batch of significant rain with this front along and north
of the Arctic coast sun and Sun night. Will see west winds 25 knots
over the western Arctic coast from Sun afternoon through Monday
night. Expect this to cause moderate surf and minor beach erosion
from Barrow west late sun through late Monday.

A 1029 mb high in the southeast Bering Sea will persist through
Monday. This will cause stratus and fog over the eastern Bering to
persist. West winds over the northern Bering will cause the stratus
and fog to remain along the West Coast of Alaska.

&&

Discussion...
models show similar solutions through Monday. After Monday start to see
differences with timing and strength of short waves between
models.

Coastal hazard potential days 3 and 4...
moderate surf and minor beach erosion from Barrow west late sun
through late Monday.

&&

Fire weather...
relative humidity expect to be above 40% most of area today...except 30-40% in
zone 224. West winds 10g20 miles per hour in the northern interior today and
this evening but with high relative humidity should limit burning.

Expect warming and drying trend from sun through Monday.

&&

Hydrology...
rivers now falling across interior
the .25-.50 inch rain in northwest Alaska expected by this afternoon will
cause rivers there to rise for the next several days.
Rain will change to scattered showers as the front moves
southeast across the interior today so not expected to cause much
change in interior rivers.

Expect another batch of significant rain along and north of the
Arctic coast sun and Sun night.

&&

Afg watches/warnings/advisories...
dense smoke advisory for akz219-akz220.
Dense fog advisory for akz224.

Small Craft Advisory for pkz220-pkz225-pkz230.

&&

$$

Jb Aug 15

National Weather Service Glossary of Abbreviations