Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
311 PM akdt Tuesday Jun 2 2015
aloft...low over Banks Island will drift west to north of Barrow
Thursday am...then southwest to near Cape Lisburne 4pm Friday. Low south
of Dutch Harbor will move to near Anchorage Friday am and weaken into
a trough. Short wave trough from Kaktovik to Cape Lisburne will
move to Anaktuvuk Pass to Bethel at noon Wednesday then from Barrow to
Kotzebue to Nunivak Island Thursday am...and from lisburne to Bethel
Friday am. Flow aloft over central interior changing from light
northerly to southwesterly overnight through Wednesday...with southerly
flow then developing over the eastern two thirds of the state by
Friday as the trough continues a further shift west.
Surface...1032 mb high over the northern Chukchi Sea will drift
west and weaken through Friday. Cold front from Kaktovik to Cape
Lisburne moving southwest to extend from Anaktuvuk Pass to
Unalakleet to Nunivak Island by 10 PM Wednesday. Weak thermal trough
from Bethel to Talkeetna to Northway this afternoon will
strengthen and extend from south of McGrath to Denali park to
Dawson Canada 4pm Wednesday then from McGrath to Fairbanks to Eagle 4pm
Thursday...and from Bettles to north of Fort Yukon to inuvik Canada 4pm
Models...agree fairly well with movement of main features in the
short term. In the medium term there is much better agreement
between the European model (ecmwf) and GFS in the upper level circulation dropping
south over the russian Arctic at the end of the time frame.
North Slope...snow in the east tapering off tonight with little
further accumulation except an inch or two in the Brooks range
through Wednesday. Some snow and afternoon rain showers lingering on
for the next few days near the Brooks range...picking up some on
Thursday and Friday as south to southwest flow moves into the eastern
portion of the Brooks range.
Western Alaska...coastal regions remaining dry with northerly
winds increasing some tonight...then not changing much through
Thursday. As the southwest flow develops over the upper Kuskokwim
valley tonight and spreads northwest through Friday will see an
increase in showers progressing northwest...tapping the moisture
from the thermal trough which is currently south of the area.
Central and interior Alaska...the cool blast of Sunday night
through this am is changing overnight and through Wednesday as the
next short wave drops to the south but west of the area...setting
up southwest flow which taps the moisture in the thermal trough
south of the Alaska Range. Showers and areas of rain will spread
north over the central interior regions late tonight into
Wednesday night. With some partial heating Wednesday expect
thunderstorms to develop from Eagle to Fairbanks to minchumina
south...likely becoming scattered in extent in the late afternoon
and early evening. Several short waves moving north in the flow
Thursday and Friday will help spread the showers to the northern zones
while tapering off some over the southern ones due to shadowing of
the Alaska Range.
Coastal hazard potential days 3 and 4...none.
Fire weather...cold advection over the Brooks range...north
interior...and West Coast zones will produce moderate northeast
winds through Thursday. Red flag warnings for zones 208...216...
and 217 are in effect through Wednesday evening...though the relative humidity
will rise above 30 percent after 11pm tonight and until noon
Wednesday. Red flag warnings will expand to zones
210...212...214...218...219...and 220 Wednesday afternoon and
continue through 11pm Wednesday night. On Thursday relative
humidity will again be 30 percent or less and with a moderate
gradient red flags may be needed for some of the West Coast zones
again. Low pressure moving north from the Alaska Range to zone 224
will bring a considerable increase of humidity in middle Tanana
Valley and east on Wednesday. Isolated wet thunderstorms are
expected over zones 224 and 226 this evening. Isolated to
scattered wet thunderstorms Wednesday afternoon and evening will
expand to zone 223...225 and southern 221.
red flag warning for akz208-akz210-akz212-akz214-akz216-akz217-
Small Craft Advisory for pkz200-pkz215-pkz220-pkz225-pkz230.
Gale Warning for pkz210.
Jl Jun 15