Area Forecast Discussion
Issued by NWS
FXAK67 PAJK 291336
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
536 AM AKDT SUN MAY 29 2016
.SHORT TERM...Broad complex upper low centered over western BC
early this morning will gradually shift westward through Sunday
night. At the surface, a weak trough which is currently over the
central panhandle will shift into the NE gulf and dissipate Sunday
evening as a surface ridge begins building over the region. This
will effectively end the offshore flow regime and the resultant
sunny skies/warm temps over the northern panhandle. By late
Sunday night expect generally cloudy skies with scattered showers
area-wide. Winds are currently northerly over the northern inner
channels and light across the south. Expect a transition to
southerly winds through Sunday night as the surface ridge begins
to build. Winds should remain on the light side.
Inherited forecast was in good shape. Changes were limited to
minor local edits for winds. Nudged high temps up a bit over the
north where there should be just high overcast for much of the
day. Brought overnight lows up some on Sunday night due to the
expected lower cloud cover and shower activity.
.LONG TERM...A broad upper low will dominate the eastern gulf, the
panhandle, and much of western Canada at the start of the
extended range forecast. This feature will weaken through Monday
night as another upper low with a surface reflection tracks north
into the central gulf on Tuesday. Resulting deep layer
southwesterly flow will allow moist onshore flow to resume across
southeast Alaska and showers will give way to rain. Model
agreement in this regard is rather good, so have gone fairly
aggressive with the pop in updates tonight. By late in the week,
models are indicating that a developing wave will enter the
southeastern gulf but there are still some timing differences.
opted to use gfs22 to depict this feature crossing the
southwestern outer coast thursday.
The Tuesday surface low will feature small craft winds over a
significant portion of the eastern Gulf and this portion of the
extended forecast has not changed. Post frontal trough associated
with the Tuesday low now looking like it will also have small
craft winds and have modified the winds over the gulf Wednesday
and Wednesday night to reflect this. As before, am not expecting
much of a wind response over the inner channels and have no small
craft conditions on the inside.
Majority of the forecast remains unchanged from yesterday, with the
exception of pop/qpf grids and Wednesday winds. Overall forecast
confidence is average.
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