• Juneau, Alaska, United States (99801)
  • WxZone: AKZ025ICAO: PAJNLat: 58.30NLon: 134.42W

Discussions

232 PM AKDT SUN AUG 29 2010

.SHORT TERM...WEAK AREA OF LOW PRESSURE OVER SOUTHEAST GULF
CONTINUING TO SLIDE SE TODAY UNDER A 120KT NW JET WITH ITS
IMPACTS SOUTH OF THE FORECAST AREA BY LATE EVENING. UPPER LEVEL
SHORT WAVE EXTENDING FROM FFIA2-PAAP ALSO HEADED SOUTH AND
MARKING DECREASING CLOUDS AND SHOWERS TO THE NORTH AND AN AREA OF
LIGHT RAIN WITH EMBEDDED CONVECTION TO THE SOUTH. AN OPEN WAVE
JUST SOUTH OF THE AK PEN WILL DEVELOP INTO A 1008 MB LOW JUST
EAST OF KODIAK THIS EVENING THAT DEEPENS TO A 1003 MB LOW WEST OF
CDE MONDAY AFTERNOON. 

SAT SHOWS OVERCAST SKIES OVER THE SOUTHERN PANHANDLE AND BROKEN
TO LOCALLY SCATTERED SKIES ACROSS THE NORTH. RADAR AND OBS SHOWS
RAIN IS CONTINUING SOUTHERN ZONES WITH ONLY ISOLATED TO SCATTERED
SHOWERS IN THE NORTH. RADAR INDICATES A FEW OF THE SHOWERS OVER
THE SOUTHEAST GULF IN LER OF JET ARE HEAVY WITH AMOUNTS OVER 0.50
INCH PER HOUR...OTHERWISE PRECIP IS MAINLY LIGHT AND INTERMITTENT.

PLAN FOR TONIGHT IS TO KEEP INMTNT RAIN IN EARLY EVENING FOR
SOUTHERN ZONES GOING TO SCT SHOWERS. WILL KEEP ISOLATED SHOWERS
ALONG THE IMMEDIATE COAST BUT NOT MENTION PRECIP FOR RMNDR INNER
CHANNELS. WITH BREAKS IN SKY COVER WILL INCLUDE PATCHY RADIATIONAL
FOG.

BY TOMORROW NEXT SYSTEM QUICKLY APPROACHES THE EASTERN GULF WITH
RAIN SPREADING PASI-PAKT LINE BY AFTERNOON. NORTH OF HERE WILL
JUST KEEP ISOLATED TO SCATTERED SHOWERS.

STILL NO SIG WINDS FOR COASTAL WATERS AND INNER CHANNELS. THE
OFFSHORE WILL BE CLIPPED BY AN AREA OF 20 KT WESTERLIES TONIGHT.
DO EXPECT A 5 TO 6 FOOT SWELL TO MAKE INTO THE COASTAL WATERS THO.
BY MON AFTERNOON WINDS GO BACK TO SE 15 KT IN THE COASTAL WATERS
AHEAD OFF NEXT FRONT.

.LONG TERM...AN UPPER LEVEL TROUGH MOVES INTO THE GULF AT THE BEGINNING
OF THE LONG TERM FOLLOWED BY A REINFORCING TROUGH TOWARD MID WEEK.
FOLLOWING THIS A PATTERN CHANGES BEGINS ACROSS THE PANHANDLE WITH
MID LEVEL RIDGING BUILDING INTO THE GULF AND MID LEVEL SHORTWAVES
AND UPPER LEVEL JET ENERGY MOVING AROUND THE PANHANDLE TO THE
SOUTH INTO THE WEEKEND. THE PAST FEW RUNS OF MODELS ARE ALSO
HINTING AT THE DEVELOPMENT OF AN INVERTED TROUGH ALONG THE OUTER
COAST TOWARD NEXT WEEKEND WHICH COULD BRING SOME NICE DRY WEATHER
TO THE PANHANDLE OVER THE LABOR DAY WEEKEND. THE FIRST MID LEVEL
SHORTWAVE AND ASSOCIATED SURFACE LOW ADVECT EASTWARD OVER BARANOF
ISLAND SHORTLY AFTER HANDOFF BRING PERIODS OF RAIN SPREADING FROM
SOUTH TO NORTH ACROSS THE PANHANDLE. ALSO SOUTH OF THE SURFACE LOW
A 30 KNOT 850 MB LLJ MOVES ONSHORE AND THIS COULD BRING SOME SMCR
LEVEL WINDS TO THE SOUTHERN COASTAL MARINE WATERS ALONG WITH
LOCALLY BREEZY CONDITIONS TO AKZ027 AND AKZ028. WITH THIS SYSTEM
MONDAY NIGHT AND TUESDAY BOTH THE 12Z NAM AND ECMWF CONTINUED TO
HAVE THE BEST RUN TO RUN CONSISTENCY AND DETAIL...WHILE THE 12Z
GFS CONTINUES TO BE THE LARGE OUTLIER WITH ITS SURFACE FEATURES
AND MID LEVEL PHASING FOR THE FIRST 3 TO 4 DAYS. FOR THIS REASON
BLENDED INHERITED GRIDS TOWARD A 12Z NAM/ECMWF BLEND THROUGH DAY 3
THEN TOWARD THE HPC SOLUTION AFTERWARD WHICH WAS A GOOD COMPROMISE
BETWEEN THE 00Z ECMWF ENSEMBLE AND THE 06Z GFS WHICH ARE SIMILAR
AND CONSISTENT AS FAR AS BRINGING THE DRIER AIR NEXT WEEKEND WITH
A SURFACE LOW UNDERCUTTING THE PANHANDLE AND INCREASING OFFSHORE
FLOW.

TUESDAY THROUGH THURSDAY NIGHT WILL SEE SEVERAL WEAK SURFACE LOWS
REMAIN IN THE NORTHEASTERN GULF AND SLOWLY FILL OVER TIME. THIS
WILL KEEP ONSHORE FLOW ACROSS THE PANHANDLE AND WITH CONTINUED
MOIST SOUTHWESTERLY TO SOUTH 850 MB FLOW WILL SEE A GOOD CHANCE OF
RAINFALL EACH DAY FROM THE OUTER COAST INLAND ACROSS THE EASTERN
INNER CHANNELS. THE DRIEST PLACE THROUGH THE MID WEEK PERIOD WILL
BE SKAGWAY AS THE AFTERNOON SEA BREEZE CIRCULATION WILL BRING
LOCALLY BREEZY CONDITIONS AND HIGHER CEILINGS WHICH WILL KEEP THE
RAINFALL LIMITED TO THE HIGHER TERRAIN. OTHER THAN THE AFTERNOON
SEA BREEZE CIRCULATIONS WINDS WILL BE RELATIVELY LIGHT DURING THE
MID WEEK PERIOD AS THE SURFACE PRESSURE GRADIENT WILL BE VERY
WEAK.

BY FRIDAY 12Z MODELS ARE INDICATING THAT A DEVELOPING SURFACE LOW
WILL UNDERCUT THE PANHANDLE AND MOVE OVER THE CHARLOTTES BRINGING
OFFSHORE FLOW IN MOST PLACES NORTH OF FREDERICK SOUND. THIS COULD
BE THE BEGINNING OF A DRY LABOR WEEKEND FOR MOST OF THE PANHANDLE
AS A MID LEVEL RIDGE BUILDING INTO THE CENTRAL GULF TOWARD THE END
OF THE WEEK WILL ALSO KEEP MID LEVEL SHORTWAVES FROM MOVING ACROSS
THE PANHANDLE. DID NOT DECREASE POPS AND SKY TOO MUCH IN THE
EXTENDED AS WANT TO SEE SOME MODEL RUN TO RUN CONSISTENCY ON THE
DRIER WEATHER PATTERN FOR NEXT WEEKEND.

FORECAST CONFIDENCE IS ABOVE AVERAGE THROUGH THURSDAY AFTERNOON AS
THE 18Z GFS IS COMING IN AND IS MORE IN LINE WITH THE 12Z
NAM/ECMWF SOLUTION FOR TUESDAY AND WEDNESDAY. EXPECT TEMPERATURES
TO BE NEAR NORMAL FOR THE NEXT WEEK WITH MINIMAL 850 MB
TEMPERATURE AND AIR MASS CHANGES. WILL SEE WET
CONDITIONS, ESPECIALLY ALONG THE OUTER COAST AND SOUTHERN
PANHANDLE, TOWARD THE MIDDLE OF THIS WEEK WITH IMPROVING AND DRIER
CONDITIONS DEVELOPING TOWARD THE END OF THE WEEK...WITH THE DRY
CONDITIONS POSSIBLY REMAINING THROUGH THE LABOR DAY WEEKEND.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.

&&

$$

MM/PSS
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