Area Forecast Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
495
FXAK67 PAJK 251635 CCA
AFDAJK

Southeast Alaska Forecast Discussion...Corrected
National Weather Service Juneau AK
832 AM AKDT MON JUL 25 2016

.SHORT TERM...Surface analysis and satellite imagery depict a
surface low moving south of Kodiak Island with ridging remaining
over the panhandle early this morning. A trough extends from this
low across south central AK into southern Yukon. This maintained
a tight pressure gradient over Lynn Canal last night into this
morning along with fresh to strong southerly winds. These
conditions will improve through the morning as the gradient
relaxes in response to dissipating trough. Models remain in good
agreement on the synoptic pattern with the low over the western
gulf and ridging hanging on over the panhandle. Rain began in
Yakutat last night and continues this morning with light showers
across the panhandle. Some breaks in sky cover over the southern
panhandle allowed some patchy fog between showers. Inherited
forecast represented this thinking well, but 00Z guidance came in
depicting a wave moving N through the central gulf tonight. Winds
over the gulf will increase to advisory levels this evening and
overnight as this wave migrates N. This will also expand
stratiform precip into the rest of the panhandle. Used GEM/EC to
capture details associated with wave tonight, otherwise, forecast
remains on track.

.LONG TERM.../ Tuesday to Sunday / High pressure off the west
coast of the lower 48 has a ridge axis to the northern British
Columbia coast which then follows the panhandle to the northern
gulf coast. A vertically stacked low about 100 nm Southeast of
Cold Bay Tuesday, that will slowly weaken and drift northeast to
just south of Prince William Sound by Thursday.

The moist onshore flow from the central Pacific across the
southeast panhandle will maintain chance to likely levels of rain
through the middle part of the week. Model solutions, which seem to
have generally good agreement, are suggesting that there will be a
pair of troughs that will organize into a band so rain on Tuesday
night and another Thursday night. Rainfall amounts through the middle
part of the week Tuesday-Thursday range from about 2 to 5 inches
depending on location and model that is being examined. Southeast
rivers and streams are at elevated levels so the hydrological
situation will be monitored closely.

Used a NAM/GEM solution for the mid range of the forecast for winds
to impact the gulf and coastal areas of Southeast. Ended up bumping
the temps a couple of degrees up from Tuesday-Thursday as well.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ043-051-052.
&&

$$

BC/Bezenek

Visit us at http://www.weather.gov/Juneau



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.