Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
445 am akdt sun Oct 19 2014
Aloft at 500 mb...broad troughing remains over the western half
of the state through Sunday. Currently a 522 dam upper low over
the Yukon Delta will merge with a 526 dam upper low in the Gulf
of Alaska and deepen to 514 dam as it sinks to south over southern
Bristol Bay by Monday morning. The upper low will continue to
deepen on Monday as it moves south of the Aleutians on Tuesday.
Upper level ridging will build once again over the Bering Sea
on Wednesday. The GFS and European model (ecmwf) continue to differ on timing and
intensity of a stronger system moving over the chukotsk peninsula
Thursday night into Friday. The European model (ecmwf) is still faster with the
system then the GFS.
At the surface...a 1038 mb high center in the high Arctic will
remain nearly stationary through Monday. A 978 mb low in the
Gulf of Alaska will move north and weaken as it moves inland on
Monday. A broad area of low pressure over the eastern Bering Sea
and Mainland Alaska will persist through Wednesday. A strong
surface low will move over the chukotsk peninsula by Friday
morning. There is still uncertainty on the intensity and location
of this low between the GFS and European model (ecmwf)...in any case a much
stronger system to impact the West Coast next week.
North Slope...easterly flow with scattered snow showers and
mixed freezing drizzle across the North Slope continue through
Sunday. The pressure gradient along the slope will strengthen
today and the easterly winds will ramp up Sunday afternoon into
Monday. Strong easterly winds of 30 to 40 miles per hour with local gusts
to 50 miles per hour are possible through Tuesday morning. Reduced visibility
is possible with areas of blowing snow over portions of the North
Slope. The winds begin to weaken from east to west on Tuesday as
the high pressure over the Arctic moves north of Banks Island by
West Coast and western interior...the strongest northerly winds
is currently located over the over the Bering Strait with scattered
snow showers from Seward Peninsula south through Tuesday with
increasing chances of snow showers across the Yukon Delta on
Monday and Tuesday as the upper low sinks over the area. A chance
of snow Friday along the West Coast with the approaching frontal
boundary from the aforementioned low over chukotsk peninsula.
Central and eastern interior...a shortwave moving over the
interior on Sunday could bring isolated to scattered snow showers from
McGrath to Tanana to Arctic Village. As the surface pressure
gradient increases on Sunday...winds will increase to around 25
miles per hour on summits.
Coastal hazard potential days 3 and 4...none
heavy freezing spray warning for pkz230-pkz235-pkz240-pkz245.
Small Craft Advisory for pkz210-pkz220-pkz225-pkz230-pkz235.
Gale Warning for pkz230-pkz235-pkz240-pkz245.
Jk Oct 14