Skip Navigation Linkwww.weather.gov 
NOAA Logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
Alaska Region Headquarters
Top left navbar Home Site Map National News Organization
  Nav bar end cap
Follow the National Weather Service Alaska Region on Facebook Follow the National Weather Service in Alaska on Twitter
UsaGov

FXAK67 PAJK 230033
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
333 PM AKST SAT NOV 22 2014
.SHORT TERM...AN UPPER LEVEL DISTURBANCE WITH A WEAK SURFACE
REFLECTION HAS BEEN MOVING OVER SOUTHEAST ALASKA FROM SOUTH TO
NORTH THROUGH THE DAY. EFFECT AT THE SURFACE HAS BEEN TO ENHANCE
SHOWER ACTIVITY AND BOOST WIND SPEEDS AND GUSTS IN THE AREA. THE
PARENT LOW ASSOCIATED WITH THE OLD FRONT REMAINS WELL TO THE WEST,
QUASI-STATIONARY OVER THE ALASKAN PENINSULA. SATELLITE IMAGERY IS
SHOWING THE LOW CONTINUING TO ADVECT UNSTABLE AIR AND SHOWERS
INTO THE GULF FROM THE WEST. ATMOSPHERE IS SUFFICIENTLY UNSTABLE
TO GIVE RISE TO THUNDERSTORMS, BUT THEY HAVE SO FAR REMAINED SOUTH
OF THE GULF. MODELED CAPE AND OTHER INSTABILITY PARAMETERS
INDICATE THE ATMOSPHERE OVER THE GULF WILL REMAIN CONVECTIVE. MID
LEVEL FORCING OVER THE GULF IS LACKING, HOWEVER, SO HAVE NOT
INCLUDED ANY THUNDERSTORMS IN THE AFTERNOON FORECAST.

DEEP, MOIST, SOUTHWESTERLY ONSHORE FLOW WILL KEEP SHOWER ACTIVITY
GOING THROUGH THE ENTIRE SHORT TERM FORECAST PERIOD. TO THE SOUTH
ALONG AN OLD FRONTAL BOUNDARY, A DEVELOPING WAVE WILL SPIN UP A
WEAK LOW LATE THIS EVENING OVER HAIDA GWAII, ENHANCING SHOWERS
OVER THE SOUTHERN PANHANDLE. THE DEVELOPING WAVE THAT FOLLOWS WILL
BE A BIT STRONGER AND TRACK FARTHER TO THE NORTH, BUT WILL NOT
ARRIVE UNTIL THE EARLY PORTION OF THE EXTENDED RANGE FORECAST.

TEMPERATURES OVER THE FAR NORTHERN INNER CHANNELS SUFFICIENTLY
COLD ENOUGH TO SUPPORT SNOW SHOWERS FOR AT LEAST PART OF THE
FORECAST AREA TONIGHT AND TOMORROW. HAVE 2.5 MORE INCHES IN THE FORECAST
THROUGH SUNDAY AFTERNOON FOR THE HAINES HIGHWAY TO ADD TO THE 4 INCHES
FROM FRIDAY NIGHT. HAVE 2 INCHES ALONG THE KLONDIKE HIGHWAY AS WELL.
EAGLE CREST SHOULD ALSO GET ABOUT 2 INCHES OF NEW SNOW TONIGHT WITH
ANOTHER 1.5 INCHES TOMORROW. ELSEWHERE DOWN LOW, NO ACCUMULATING
SNOW IS EXPECTED TONIGHT AND WITH SNOW LEVELS CREEPING BACK UP
TOMORROW, NONE TOMORROW EITHER.

SOUTHERLY WINDS ON THE INSIDE AND OVER THE COASTAL MARINE ZONES
GENERALLY 20 KTS OR LESS WITH SIMILAR VALUES FOR EASTERLY OUTFLOW
WINDS OUT OF CROSS SOUND AND ICY STRAIT. EXCEPTION IS COASTAL
MARINE ZONE 52, WHERE A WEAK BARRIER JET UP TO 25 KTS IS EXPECTED TO
FORM TOMORROW NEAR THE COAST AND WEST OF ICY BAY. SEAS ON THE
OUTSIDE ARE STILL RUNNING QUITE HIGH AT AROUND 13 FEET WITH MOST
OF THIS BEING A SOUTHWESTERLY SWELL AT 8 TO 11 SECONDS PERIOD.
SMALL CRAFT ADVISORIES FOR SEAS FOR THE REMAINDER OF THE COASTAL
MARINE ZONES. BRIEF WIND SPEED EXCURSIONS UP TO OR EVEN ABOVE 25
KTS POSSIBLE OVERNIGHT FOR THE INNER CHANNELS, BUT AM EXPECTING
OVERALL CONDITIONS ON THE INSIDE TO REMAIN BELOW SMALL CRAFT
LEVELS. 

USED NAM FOR PRESSURE AND WIND TODAY. POP AND QPF A BLEND OF GEM
AND ECMWF. TEMPS FROM MOS AND NAM. SNOW LEVELS DERIVED FROM NAM AS
WELL. OVERALL FORECAST CONFIDENCE ABOVE AVERAGE. 
.LONG TERM...MODEL SOLUTIONS CONTINUE TO DIVERGE EARLY IN THE
PERIOD WITH A MINOR SHORTWAVE ROTATING ACROSS THE PANHANDLE
RESULTING IN A BAROCLINIC LOW DEVELOPING NEAR PRINCE OF
WALES/SOUTHERN BARANOF ISLAND SUN NIGHT INTO MON MORNING. GEM
REMAINS A STRONG OUTLIER WITH SFC LOW DEEPENING TO 990MB WHILE THE
NAM BOTTOMS OUT AROUND 1002MB. MEANWHILE THE EC AND GFS DON'T
DEVELOP A CLOSED CIRCULATION WITH AN OPEN WAVE AROUND 1004MB
MOVING THROUGH MON. GIVEN THAT ALL MODELS SHOW A JET STREAK RIDING
OVER THE RIDGE TO THE SOUTH MON...THE RF QUADRANT OF THE STREAK
SUPPORTS A DEVELOPING LOW. MAIN FORECAST CHALLENGE IS THE
LOCATION OF THIS FEATURE. KEPT STRONGEST WINDS OVER THE SOUTHERN
PANHANDLE WITH THE SFC LOW PROGGED TO BEGIN MOVING INLAND NEAR
CAPE DECISION MON MORNING. KEPT WINDS BELOW STRONG WIND HEADLINE
CRITERIA BUT WOULDN'T BE SURPRISED IF CLARENCE STRAIT EXPERIENCED
GALES FROM THIS STORM. THIS DEVELOPING LOW ALONG WITH CONTINUED
DEEP ONSHORE AND DIFFLUENT FLOW ALOFT WILL MAINTAIN NUMEROUS TO
SCT SHOWERS THROUGH THE DAY BEFORE SLOWLY DIMINISHING TUE.

NEXT FEATURE OF INTEREST WILL BE ANOTHER TROUGH DEEPENING OVER THE
BERING SEA RESULTING IN A BUILDING RIDGE OVER THE GULF OF AK.
ALTHOUGH MODELS SHOW POOR RUN TO RUN CONSISTENCY WITH THIS FEATURE
ENSEMBLE MEANS CONTINUE TO FAVOR THIS DEVELOPMENT. TRENDED
FORECAST DRIER WED AND THU AS A MORE NORTHERLY FLOW DEVELOPS OVER
THE REGION. ONLY POTENTIAL FLY IN THE OINTMENT WILL BE AN UPPER
LOW S OF THE RIDGE. DEPENDING ON HOW FAR N THIS FEATURE MOVES...SOME
MOISTURE COULD SPREAD FAR ENOUGH N TO BRING SOME PRECIP TO THE
SOUTHERN PANHANDLE. 

OVERALL...TRENDED FORECAST TOWARDS THE NAM MON...EC TUE AND THEN
USED WPC GUIDANCE THROUGH THE REMAINDER OF THE EXTENDED.
&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-052. 
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041>043-051. 
&&

$$

FRITSCH/BC

VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU


Alaska Region Headquarters
222 West 7th Avenue #23
Anchorage, AK 99513-7575
Voice: 1-907-271-5088
Fax: 1-907-271-3711
Recorded Forecast: 1-800-472-0391
Webmaster Email: ARH Webauthors
Page Modified: 03 Feb 2008 18:00 UTC
About Us
Career Opportunities
Glossary
Credits
Disclaimer
Privacy Policy