Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/25/22
Southeast Alaska Forecast Discussion...CORRECTED
National Weather Service Juneau AK
352 PM AKDT Sun Apr 24 2022
.SHORT TERM.../Through Monday night/...A weakening low south of
the Gulf of Alaska will continue to rotate showers north over the
Panhandle through this short term forecast period. The low is
already weak enough and far enough to the south that winds will
not be impactful through the period. Small craft advisories are
limited to the coastal marine zones for residual seas, which will
subside to less than 8 feet overnight. Some patchy fog may form
but is not expected to be impactful either. Cloud cover will
persist with the shower activity, limited both daytime heating and
overnight cooling. Boring short term forecast.
.LONG TERM...No change in thinking for the extended period as
ensemble means continue to struggle finding common ground on
developing surface features. A lingering low pressure will move
south of Haida Gwaii Tuesday keeping showers across the southern
panhandle. Also, a broad area of low pressure develops over BC
Tuesday. Operational models want to bring an organized band of
precip over the Coast Mountains Tuesday afternoon through
Thursday. It is a common understanding that these models do not
resolve the topography well along these mountains and will
typically over do the amount of precip that moves over the
panhandle. This is where the forecast challenge lies. Decided to
bring scattered to numerous showers over the panhandle with the
associated easterly wave with the caveat that there will be
extended periods of dry weather. As expected, as the area of low
pressure develops over BC, mostly cloudy skies will remain over
the panhandle through mid week. Day time temperatures were
cooled through the period and over night lows were slightly raised
with the increased cloud cover.
.AVIATION...Broken to overcast conditions will continue over
Southeast Alaska through the next 24 hours as bands of showers
rotate north-northwest from a low south of the Gulf. CIGS
remaining between 1K and 3K with occasional excursions into IFR.
Marginal reductions to visibility will be mostly a result of
shower activity but genuine fog is possible late tonight in some
locations. The low level jet has relaxed and no LLWS is expected.
Any turbulence will be light. The freezing level remains low -
between 2500ft and 3500ft based on MDCRS data - and there have
been several PIREPS received today reporting light rime icing.
Little change is expected tomorrow.
MARINE...Small Craft Advisory for PKZ041>043-051-052.
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