355  
FXAK67 PAJK 272311  
AFDAJK  
 
SOUTHEAST ALASKA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JUNEAU AK  
311 PM AKDT MON MAR 27 2017  
   
SHORT TERM
 
A COMPLEX MESS OF SYSTEMS WILL BE AFFECTING THE  
AREA THROUGH TUE. A LOW OVER THE E-CENTRAL GULF WILL MOVE NNW AND  
DISSIPATE ALONG THE N GULF COAST BY LATE THIS EVENING. ANOTHER LOW  
WILL MOVE NE ACROSS HAIDA GWAII LATE TONIGHT, THEN INTO CENTRAL BC  
TUE. YET ANOTHER LOW WILL MOVE N INTO THE W GULF TUE. THE LOWS  
WILL ALSO HAVE SFC TROFS ASSOCIATED WITH THEM, MAINLY ON S AND E  
SIDES. USED BLEND OF THE 12Z GFS AND NAM TO HANDLE THINGS THROUGH  
TUE.  
 
MAIN FORECAST CONCERNS WILL BE PRECIP POTENTIAL/PTYPE/AMOUNTS AND  
WINDS. AS OF 23Z...RAIN WAS FALLING OVER MOST OF THE AREA, WITH  
SOME SNOW STILL REPORTED OVER THE HAINES/CHILKAT VALLEY AREA. AS  
LOW MOVES PAST AREA TO THE W TONIGHT, IT WILL SWEEP A TROF THROUGH  
THE AREA AND PRECIP SHOULD BECOME SHOWERY AND DIMINISH OVER THE N  
AND CENTRAL PANHANDLE. THE FAR S WILL KEEP SOME RAIN GOING AS  
NEXT LOW BRUSHES PAST THEM TO THEIR S OVERNIGHT AND TUE MORNING.  
ONCE THIS LOW MOVES INLAND TUE AFTERNOON PRECIP SHOULD DECREASE  
OVER THE S. OVER THE NE GULF COAST, THEY WILL BE IN AND OUT OF  
PRECIP THROUGH TUE WITH MULTIPLE LOWS/TROFS AFFECTING THEM. THE  
SNOW IN THE HAINES/CHILKAT VALLEY AREA SHOULD CHANGE TO RAIN AS  
WARMER AIR MOVES IN THIS EVENING. NOT EXPECTING MUCH MORE SNOWFALL  
THERE...POSSIBLY ANOTHER INCH OR TWO.  
 
WINDS WILL BE STRONGEST NEAR THE MULTITUDE OF LOWS AND TROFS. UP  
TO SCA LEVEL WINDS ARE EXPECTED NEAR THE MAIN LOWS AND TROFS  
MOVING THROUGH, WITH MOST OF THE STRONGER WINDS OVER THE GULF.  
WILL HAVE SOME 20-25 KT E-SE WINDS OVER MUCH OF THE CENTRAL AND S  
INNER CHANNELS UNTIL TROF MOVES THROUGH THIS EVENING. AFTER THAT,  
WINDS ON INNER CHANNELS WILL BE IN THE 10-20 KT RANGE ALTHOUGH THE  
CENTRAL INNER CHANNELS MAY GET FAIRLY LIGHT OVERNIGHT AND TUE  
MORNING WITH WEAK PRESSURE GRADIENT THERE.  
 
OTHERWISE, THINK CENTRAL PANHANDLE COULD GET PATCHY FOG OVERNIGHT  
AS BREAKS IN CLOUDS OCCUR AND WINDS BECOME LIGHT. IT WILL BE  
RATHER SHORT LIVED THOUGH AS TEMPS WILL RAPIDLY WARM TUE MORNING  
IN THE LATE MARCH SUN.  
   
LONG TERM
 
/TUE NIGHT THROUGH MON/ UPPER LEVEL TROUGH OVER THE  
AK PENINSULA WILL FINALLY SHIFT TO THE NORTHEAST WHILE AN UPPER  
LEVEL RIDGE CROSSES IN TO THE CENTRAL AK GULF BY WEDNESDAY  
EVENING. AS THE RIDGE CONTINUES TO TRACK EASTWARD OVER THE  
PANHANDLE THE NEXT SIGNIFICANT LOW WILL MOVE JUST SOUTH OF THE  
ALEUTIAN CHAIN BY THURSDAY. THIS UPPER LOW WILL THEN EXPAND OVER  
THE WESTERN PORTION OF THE AK INTERIOR BY FRIDAY. AFTER  
THAT...UNCERTAIN ON HOW IT WILL EVENTUALLY MOVE.  
 
AT THE SURFACE, THE LOW MOVING UP THE CENTRAL GULF WILL REACH  
PRINCE WILLIAM SOUND TUESDAY EVENING WITH THE ASSOCIATED FRONT  
TRACKING OVER THE EASTERN GULF AND THEN THE PANHANDLE THROUGH  
WEDNESDAY. GULF WINDS PICK UP TO MAX SMALL CRAFT ALONG THE FRONT  
WITH POTENTIAL GALES. PRECIP FROM THIS FRONT WILL MAINLY BE  
FOCUSED ON THE NORTHEAST GULF AND NORTH CENTRAL PANHANDLE.  
SOUTHWESTERLY FLOW STARTING A WARMING TREND SO EXPECT MORE RAIN  
THAN SNOW WITH ONLY MINOR ACCUMULATIONS OF A COUPLE OF INCHES FOR  
THE FAR NORTH AND AT HIGHER ELEVATIONS. SURFACE RIDGE BUILDS OVER  
THE GULF BEHIND THE FRONT FOR A DRYING TREND STARTING LATE  
WEDNESDAY NIGHT INTO THURSDAY. THIS WILL BE SHORT LIVED.  
 
THE NEXT MAJOR LOW WILL HAVE MOVED SOUTH OF THE ALEUTIANS BY THIS  
TIME WITH ASSOCIATED GALE FORCE FRONT CROSSING INTO THE CENTRAL  
GULF. THE FRONT WILL REACH THE EASTERN GULF THEN PANHANDLE EARLY  
THURSDAY EVENING INTO FRIDAY MORNING. WINDS WILL REACH AT LEAST  
GALE FORCE OVER THE GULF AND POTENTIALLY HIGHER. SMALL CRAFT  
WINDS WILL INCREASE OVER THE INNER CHANNELS. WITH THE WARM  
SOUTHERLY FLOW ONCE AGAIN EXPECT MORE RAIN THAN ANYTHING FROM THIS  
FRONT, BUT THAT RAIN MAY BE HEAVY. THE SURFACE LOW WILL  
EVENTUALLY TRACK EASTWARD THROUGH THE WEEKEND FOLLOWED BY WEAK  
RIDGING.  
 
NEW MODEL RUNS WERE MOSTLY IN LINE WITH PREVIOUS FORECAST  
REGARDING POSITION OF THE INCOMING SYSTEM, A SLIGHT INCREASE IN  
SPEED FOR THE THURSDAY EVENING LOW/FRONT. MOSTLY  
REFRESHED/INCREASED WINDS TO A BLEND OF GFS/ECMWF AND INCREASED  
POPS FOR THE THURSDAY FRONT. DUE TO SOUTHWESTERLY FLOW DID NOT  
DROP POPS OFF COMPLETELY BETWEEN SYSTEMS BUT GREATEST CHANCE FOR  
DRY/CLEAR SKIES IS OVER THE SOUTHERN PANHANDLE. MORE INDICATIONS  
OF WARMER OVERNIGHT TEMPS DUE TO HIGHER 850 MB TEMPS/SW FLOW AND  
PRECIP/CLOUD COVER SO ALSO NUDGED UP LOWS A FEW DEGREES. FORECAST  
CONFIDENCE IS AVERAGE.  
 

 
   
AJK WATCHES/WARNINGS/ADVISORIES
 
 
PUBLIC...NONE.  
MARINE...SMALL CRAFT ADVISORY FOR PKZ022-034-036-043-051>053.  
SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ041-042.  

 
 

 
 
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