894
FXAK67 PAJK 201442
AFDAJK
SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
542 AM AKST WED NOV 20 2024
SHORT TERM.../THROUGH WEDNESDAY NIGHT/
COLD AIR OUTFLOW
REMAINS THE BIG STORY THROUGH THE REMAINDER OF THE WEEK ACROSS SE
AK. A STRONG LOW WHICH QUICKLY STRENGTHENED WEST OF WASHINGTON
STATE, ALONG WITH A MODEL PROGGED 1050 MB CANADIAN HIGH OVER THE
YUKON, ARE CONTRIBUTING TO A STRONG PRESSURE GRADIENT ACROSS THE
PANHANDLE. THE RESULTING EARLY SEASON COLD AIR OUTFLOW EVENT HAS
RESULTED IN WINDS APPROACHING STORM FORCE IN LYNN CANAL, WITH
GALES AND SMALL CRAFTS ACROSS THE REMAINDER OF THE INNER CHANNELS.
WINDS IN SOME LAND- BASED LOCATIONS WILL LIKEWISE BE ON THE
STRONGER SIDE, WITH THE POTENTIAL FOR MOUNTAIN WAVE ACTIVITY IN
SOME AREAS. IN PARTICULAR, DOWNTOWN JUNEAU AND DOUGLAS WILL SEE
MOUNTAIN WAVE POTENTIAL THROUGH THE NEXT FEW DAYS AS CROSS BARRIER
FLOW CONTINUES TO REMAIN STRONG THOUGH THE LACK OF A PRE-EXISTING
CRITICAL LAYER WILL HAMPER WINDS FROM APPROACHING THOSE SEEN IN
SOME OF THE MORE IMPRESSIVE TAKU EVENTS. TEMPERATURES HAVE ALSO
DIPPED SHARPLY BELOW NORMAL, AND WILL REMAIN BELOW NORMAL THROUGH
THE DURATION OF THE EVENT. ANTICIPATE RELATIVELY CLEAR SKIES
BARRING SOME UPPER LEVEL CLOUDS THROUGH WEDNESDAY, WITH DRY
CONDITIONS LASTING ACROSS THE PANHANDLE.
LONG TERM.../THURSDAY THROUGH TUESDAY/
BLOCKING PATTERN OVER THE
REGION BEGINS TO BREAK DOWN AT THE END OF THE WEEK AND INTO THE
WEEKEND BEGINNING THE TRANSITION FROM THE VERY COLD, DRY, AND WINDY
NORTHERLY OUTFLOW CONDITIONS. DIMINISHING PRESSURE GRADIENTS AS THE
YUKON HIGH AND LOW OFF THE COAST OF WASHINGTON STATE WEAKEN WITH A
WEAK LOW TRACKING INTO THE NE GULF. WINDS REMAIN ELEVATED INTO
FRIDAY WITH GALES OVER THE INNER CHANNELS AND OVERLAND GUSTS IN THE
35 TO 45 MPH RANGE THEN THE DROP OFF SATURDAY INTO SUNDAY. FRONT
ASSOCIATED WITH THE LOW HAS A CHANCE TO MOVE IN MONDAY WITH LIGHT
PRECIP INDICATED BY ENSEMBLES BUT LATEST OPERATIONAL MODELS KEEP IT
OFFSHORE UNTIL TUESDAY. ONCE AGAIN ENSEMBLES PUT IN A BROAD LOW OVER
THE AK GULF WITH A FRONT REMAINING OVER SE AK. MEANWHILE GFS/ECMWF
OPERATIONAL MOVE IN ANOTHER RIDGE KEEPING ANY PRECIP OVER THIS TIME
FAIRLY LIGHT WITH MORE BREAKS. ANY PRECIP FOR THE INITIAL FRONT WILL
LIKELY BE SNOW. WITH THE COLD AIR IN PLACE AND A WARM MOIST MID
LEVEL AIR MASS TO THE WEST BEHIND THE RIDGE OVER RUNNING SNOW EVENTS
NOT OUT OF THE QUESTION. RIGHT NOW GFS/ECMWF HAVE 24 HOUR AMOUNTS IN
THE 3 TO 5 INCH RANGE MID WEEK. BUT 850 MB TEMPS CREEP UP TO THE -3
TO -6 C RANGE WHICH GETS MORE TOWARDS A SNOW/RAIN MIX OR POSSIBLY
ALL RAIN, ESPECIALLY FOR THE SOUTH. HIGH CONFIDENCE IN OVERALL
WEATHER PATTERN INTO SUNDAY WITH LOWER CONFIDENCE IN CONDITIONS NEXT
WEEK.
AVIATION
VFR SKC WITH OUTFLOW WINDS. SHEEP MOUNTAIN IN THE
JUNEAU AREA REPORTED NORTHERLY GUSTS TO 135MPH EARLY THIS MORNING.
EXPECT A BUMPY RIDE OVER THE REGION TODAY FROM LLWS WITH THE AAWU
HIGHLIGHTING OCNL TO CONS MOD LOW LEVEL TURBULENCE.
MARINE
STORM FORCE WINDS FOR LYNN CANAL, ALONGSIDE GALES AND
SMALL CRAFT CONDITIONS FOR THE INNER CHANNELS AND OUTER COASTAL
WATERS ARE ANTICIPATED. IT SHOULD BE NOTED THAT A LARGE COMPONENT
OF THESE WINDS WILL BE OUTFLOW IN NATURE, MEANING THAT SOME
LOCATIONS WILL SEE DRAMATICALLY STRONGER WINDS AS COMPARED TO JUST
A FEW MILES IN EITHER DIRECTION. FREEZING SPRAY IS ALSO POSSIBLE
FOR SOME MARITIME AREAS, ESPECIALLY THE NORTHERN INNER CHANNELS.
AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...COLD WEATHER ADVISORY UNTIL 9 AM AKST THIS MORNING FOR AKZ318.
STRONG WIND THROUGH LATE TONIGHT FOR AKZ318.
STRONG WIND UNTIL 9 AM AKST THIS MORNING FOR AKZ323.
HIGH WIND WARNING UNTIL 6 AM AKST EARLY THIS MORNING FOR AKZ325.
STRONG WIND FROM 3 PM AKST THIS AFTERNOON THROUGH LATE TONIGHT
FOR AKZ325.
MARINE...STORM WARNING FOR PKZ012.
GALE WARNING FOR PKZ013-022-031>033-641>644-651-661>664-671.
SMALL CRAFT ADVISORY FOR PKZ011-021-034>036-053-672.
SHORT TERM...GFS
LONG TERM....PRB
AVIATION...AP
MARINE...GFS
HYDROLOGY...99
VISIT US AT HTTP://WWW.WEATHER.GOV/JUNEAU
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page