High Surf in Hawaii, January 3 to 6, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST SAT JAN 3 2009

.SYNOPSIS...
THE UPPER LOW SOUTHWEST OF THE STATE WILL CONTINUE TO MOVE
SOUTHWEST INTO THE WEEKEND. HIGH PRESSURE WILL STRENGTHEN FAR
NORTHEAST OF THE STATE...RESULTING IN BREEZY...GUSTY
TRADES. THE HIGH WILL MOVE OFF TOWARD THE WEST COAST ALLOWING THE
TRADE WINDS TO BECOME LIGHT TO MODERATE BY TUESDAY. ANOTHER COLD
FRONT WILL APPROACH THE ISLANDS NEXT WEEKEND.

&&

.DISCUSSION...
WV IMAGERY DEPICTS UPPER LEVEL LOW PRES CONTINUING TO MOVE SW AWAY
FROM HI TONIGHT. A FEW S/W IMPULSES ARE STILL TRIGGERING TSTORMS IN
THE NE QUADRANT OF THE LOW WHERE INSTABILITY IS STILL INTERACTING
WITH ABUNDANT LOW LEVEL MOISTURE. THE TSTORM AND MOD/HEAVY RAIN
THREAT HAS DIMINISHED FOR THE ISLANDS AND COASTAL ZONES. SHOWER
ACTIVITY ACROSS THE STATE REMAINS SCATTERED YET LIGHT. MUCH DRIER
AIR IS NOSING IN FROM THE NE AS NOTED IN THE POES AND SSM/I DATA.
RAINFALL TOTALS OVER THE PAST 3 TO 6 HRS REMAIN UNIMPRESSIVE AND
POPS FOR SAT HAVE BEEN LOWERED.

HIGH PRES NE OF THE STATE WILL STRENGTHEN AT THE SFC AS A RESULT OF
RIDGING ALOFT INTO THE WEEKEND. LOCALLY BREEZY TRADE WINDS WILL
AFFECT ALL ISLANDS AND COASTAL ZONES THROUGH MON. SHOWER ACTIVITY
WILL FOCUS BACK TO WINDWARD/MAUKA REGIONS. MID LEVEL RIDGING AND THE
RESULTANT SUBSIDENCE INVERSION WILL GREATLY LIMIT VERTICAL
DEVELOPMENT AND INTENSITY OF THE SHOWERS.

AS A MORE ZONAL PATTERN BEGINS TO TAKE HOLD OF THE NPAC...HIGH PRES
WILL BEGIN SLIDING TOWARD THE MAINLAND AS ANOTHER S/W TROUGH
APPROACHES FROM THE W. BOTH THE ECMWF/GFS FLATTEN THE TROUGH AND
MAINTAIN PROGRESSIVE FLOW MOVING IT QUICKLY NE THROUGH THE MIDDLE OF
THE WEEK WHICH WILL PREVENT THE ASSOCIATED SFC CDFNT FROM REACHING
HI...BUT TRADE WINDS WILL WEAKEN TUE INTO THE MIDDLE OF THE COMING
WEEK.

THE GFS/GFS ENSEMBLES AND THE ECMWF REMAIN IN FAIR AGREEMENT
REGARDING THE EVOLUTION OF A SYNOPTIC SCALE TROUGH TO THE NW FOR
DAYS 5-7. SUBSTANTIAL DIFFERENCES DO ARISE IN THE AMPLICATION OF THE
H5 TROUGH AND THE SEWD PROGRESSION OF THE SFC CDFNT NEXT WEEKEND.
FOR NOW...WILL BE LEANING TOWRD THE SLOWER ECMWF/GFS ENEMBLES
KEEPING THE FRONT NW OF THE AREA THROUGH THE FORECAST PERIOD KEEPING
SIGNIFICANT POPS OVER THE NWRN PORTION OF THE STATE/COASTAL ZONES.

&&

.MARINE...
THE INCREASING TRADE WINDS WILL GENERATE LARGE EASTERLY WINDSWELL
THAT WILL EXCEED THE ADVISORY LEVEL OF 8 FEET FOR EXPOSED E FACING
SHORES THROUGH SUNDAY NIGHT. THE SMALL CRAFT ADVISORY HAS ALSO BEEN
EXPANDED TO ALL HAWAIIAN WATERS. EVEN AS WINDS BEGIN TO SLOWLY BACK
DOWN...CONDITIONS IN SOME OF THE WINDIER AREAS WILL STILL MEET SCA
CRITERIA AS MENTIONED IN THE W/W/A BELOW.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY UNTIL MONDAY AFTERNOON FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.

SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING THROUGH 6 PM SUNDAY
AFTERNOON FOR ALL HAWAIIAN WATERS.

HIGH SURF ADVISORY FOR EXPOSED EAST FACING SHORES OF
KAUAI-OAHU-MOLOKAI-MAUI-BIG ISLAND.

&&

DEJESUS