Scientific Forecaster Discussion
Northern Alaska forecast discussion
National Weather Service Fairbanks Alaska
230 am akdt Thursday Aug 21 2014
Upper air...a light west to southwest flow pattern will persist
over the northern Alaska interior through Sat. A weak upper low
center about 650 miles north of Barrow will move to 650 miles
north of the MacKenzie river Delta area by early Sat morning. A
short wave trough extending from the low center to wrangel island
will move slowly eastward while gradually weakening. By early Sat
morning the trough will extend from the upper low center to
Barrow then southward near Ambler. By early Sun morning the short
wave will lie along the alcan border from the Arctic coast to
north of Eagle. Another short wave trough will move eastward to
the western Beaufort Sea and the Chukchi Sea by early Monday
morning...as a strong upper low moves across the high Arctic
region strong an upper low centered near Shemya will move on a
wobbly course to Bristol Bay by sun evening.
a broad area of high pressure with a weak gradient lies over the
northern Alaska Mainland and the Beaufort and chukchi seas. A
weather front extends from a 991 mb low center about 180 miles
north of ostrov kotelnyy in the new siberian islands southward to
the russian Arctic coast. The low center will move to about
82n/149e by early Friday weakening to 999 mb and dissipate over the
high Arctic Friday night. By early Friday morning the weather front will
extend from the 999 mb low southward to the northern Russia coast.
By early Sat morning...a new 1004 mb low center will develop near
79n/171e...about 500 miles north of wrangel island. The weather
front will extend from the low center south southeastward across
the Beaufort Sea and into the Chukchi Sea.
today...isolated afternoon thunderstorms in zone 206.
Isolated afternoon/evening thunderstorms in eastern zone
218/eastern zone 220/eastern zone 224.
Friday...isolated afternoon/evening thunderstorms in zone 224.
Saturday...isolated afternoon thunderstorms in zone 224.
Scattered or numerous showers expected over much of the
northern/eastern interior and interior Arctic slope this
afternoon/evening. Less shower activity is expected Friday.
Areas of fog expected over the marine forecast areas and
adjacent coastal areas.
Coastal hazard potential days 3 and 4...none.
Medium range outlook...GFS/ECMWF models indicating a more active
pattern in the high Arctic as a very deep and cold polar
vortex...below 510 dam at 500 mb...moves out of the far
northwestern Arctic center. Current GFS/European model (ecmwf) differ on the
position...average of the 21/00z GFS and European model (ecmwf) model runs gives a
position near 80n/160e by 18z Tuesday and near 80n/172e by 18z Wednesday.
Vertically stacked surface low center will be around 989 mb by 18z
Tuesday and 985 mb by 18z Wednesday...again using the average of the 21/00z
GFS and European model (ecmwf) runs. The circulation around the surface center will
cover the Chukchi Sea and most of the Beaufort Sea. Weak west to
southwest upper flow pattern continuing over northern Alaska south
of the Brooks range through the middle of next week...weather will
likely be limited to spotty showers over interior areas.
none. Min relative humidity in the higher expected to be around 40 percent or
higher through Sat.
Small Craft Advisory for pkz225-pkz230.
Rf Aug 14