Scientific Forecaster Discussion
Southcentral and southwest Alaska forecast discussion
National Weather Service Anchorage Alaska
132 PM akdt Wednesday Jul 30 2014
Analysis and upper levels...
there is a stable "omega block" over the area with the upper level
ridge over the central/eastern Bering Sea and an upper low over
the Gulf of Alaska and another low to the southwest of the western
the numerical models are in good agreement today. This is not a
surprise...considering the stable blocking pattern over the area.
Forecast confidence is higher than normal for the afternoon
Short term forecast...
For south central Alaska...mainly dry conditions are expected
into Friday with the blocking high keeping any organized weather
systems away from the area. The exception is some diurnal mountain
convection. This convection will be very limited this
evening...then increases slightly for Thursday and Friday. Late
Friday into Saturday a system will slide around the top of the
ridge and push into south central Alaska from the northwest.
Precipitation from this system will likely push into the Susitna
Valley on Saturday...but not much further south as it stalls and
For southwest Alaska...some moisture will sneak around the top of
the ridge late tonight and very slowly push across the area into
Saturday. This push chances of rain/showers slowly towards the
southeast...although slowing almost to a stop on Saturday.
For the Bering Sea/Aleutians...the pattern will change very little
over the next few days. The blocking ridge will slowly drift
northwest...with the center of the high moving from the central
Bering Sea tonight to the northwest coast of the Bering on
Long term forecast...
the Omega blocking over the Bering Sea will continue with stratus
and fog with light winds through Sunday. By Monday an upper level
weak shortwave trough will drop down from the upper Kuskokwim
valley into the southwest Alaska region. This will bring increased
clouds and showers throughout the area. By Sunday the the weak
upper level ridge in southcentral Alaska will be exiting the
region...followed by an upper level trough pushing into the Gulf
of Alaska bringing northeasterly winds and increased cloud cover
with rain along the coastline before spreading inland.
Ludwig/period Jul 14