Drought in Hawaii, February 1 to 28, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST MON JAN 31 2011

.SYNOPSIS...
REMNANT MOISTURE LEFT BEHIND BY A DISSIPATED COLD FRONT WILL AFFECT
WINDWARD BIG ISLAND AND MAUI TONIGHT. OTHERWISE A DRY AND STABLE
AIRMASS WILL REMAIN IN PLACE ACROSS THE STATE THROUGH MID WEEK. WEAK
HIGH PRESSURE PASSING NORTH OF THE STATE WILL BRING MODERATE TRADE
WINDS THROUGH TUESDAY. WINDS WILL START TO TURN TO THE SOUTHEAST AND
SOUTH FOR THE SECOND HALF OF THE WORK WEEK...AHEAD OF A STRONGER
COLD FRONT APPROACHING FROM THE NORTHWEST. THIS FRONT WILL BRING
WIDESPREAD RAINFALL THIS WEEKEND.

&&

.DISCUSSION...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH SOUTHEAST OF THE BIG
ISLAND...WITH A RIDGE BUILDING IN FROM WEST OF THE STATE. AT THE
SURFACE...A DISSIPATING FRONT IS LOCATED JUST SOUTHEAST OF THE BIG
ISLAND WHILE HIGH PRESSURE NORTH OF THE STATE IS SLIDING EASTWARD
AND MODERATE TRADE WINDS WILL CONTINUE TO PRODUCE IN DRY AND STABLE
CONDITIONS THROUGH MIDWEEK. 00Z SOUNDINGS FROM HILO AND LIHUE SHOW
PRECIPITABLE WATERS RANGING FROM 0.98 INCHES IN HILO TO 0.62 INCHES
IN LIHUE. INVERSION HEIGHTS ALSO RANGE FROM 7500 FT AT HILO TO 4000
FT AT LIHUE. AMSU/SSMI BLENDED TOTAL PRECIPITABLE WATER IMAGERY
SHOWS THE DRY AIRMASS ACROSS KAUAI THROUGH MAUI AND MOVING EASTWARD
ACROSS THE BIG ISLAND THIS EVENING.

SHORTWAVE INFRARED SATELLITE AND RADAR SHOW AN AREA OF SHOWERY
CUMULUS CLOUDS OVER WINDWARD BIG ISLAND AND ALSO UPSTREAM TO THE
NORTHEAST. WITH MODERATE TRADES IN PLACE AND REMNANT FRONTAL
MOISTURE IN PLACE...LIGHT TO MODERATE SHOWERS WILL BE POSSIBLE FOR
WINDWARD MAUI AND BIG ISLAND THROUGH THE NIGHT. VERY FEW CLOUDS ARE
IN PLACE ACROSS THE WESTERN ISLANDS. WINDS ARE EXPECTED TO BE GENTLE
TO MODERATE AND VEER EASTERLY BY TUESDAY AS THE EASTWARD MOVING HIGH
CENTER NORTH OF THE AREA DRIFTS FURTHER AWAY.

THE RETURN TO TRADE WINDS WILL BE BRIEF. WHILE THE HIGH SHIFTS
FARTHER NORTHEAST OF THE STATE...THE RIDGE NORTH OF US WILL BE
DISPLACED SOUTHWARD BY THE NEXT DEVELOPING FRONT FAR NORTHWEST OF
THE AREA. BY WEDNESDAY...GFS/ECMWF/NAM SHOW WINDS ALREADY BEGINNING
TO VEER SOUTHEASTERLY NEAR KAUAI. AS WINDS VEER ACROSS THE
AREA...THE SOUTHEASTERLY FLOW WILL BEGIN TO DRAW ADDITIONAL
LOW-LEVEL MOISTURE ACROSS THE ISLANDS LATE IN THE WEEK...ALTHOUGH PW
VALUES ARE EXPECTED TO REMAIN BELOW NORMAL UNTIL FRIDAY WHICH WILL
ALLOW FOR AN UPTICK IN SHOWERS AND CLOUDS ACROSS THE AREA. THE KONA
WIND FLOW LATE THIS WEEK WILL ALSO RESULT IN ELEVATED HUMIDITY
LEVELS AROUND THE STATE.

THE NEXT MAJOR COLD FRONT APPROACHES THIS WEEKEND. AHEAD OF THE
FRONT...STRONG MOISTURE ADVECTION AND CONVERGENCE WILL LEAD TO
WIDESPREAD PRE-FRONTAL SHOWERS OVER THE STATE ON SATURDAY. THERE
REMAINS TIMING DIFFERENCES IN TERMS OF WHEN THE FRONT PASSES BETWEEN
THE EXTENDED MODELS...WITH THE GFS ABOUT 6-12 HOURS FASTER THAN THE
ECMWF AND NOGAPS FRIDAY NIGHT AND SATURDAY. THE GFS SHOWS THE FRONT
STALLING NEAR KAUAI SUNDAY AND DISSIPATING MONDAY. THE ECMWF PUSHES
THE FRONT THROUGH TO THE CENTRAL PORTION OF THE STATE BEFORE
STALLING AND DISSIPATING MONDAY. THESE DIFFERENCES IN SOLUTIONS ARE
INDICATIVE THAT THE EXACT TIMING AND IMPACT OF THIS FRONT IS STILL A
BIT UNCERTAIN.

&&

.MARINE...
POST-FRONTAL FRESH NORTHEAST WINDS WILL VEER EAST TONIGHT AND WEAKEN
DOWN TO MODERATE BREEZES OVER THE WATERS AS THE HIGH NORTH OF THE
STATE MOVES SLIDES EASTWARD.

THE CURRENT LARGE NORTHWEST SWELL HAS PEAKED AND IS SLOWLY STARTING
TO DIMINISH AT BUOY 51101. THE WAIMEA BAY BUOY REPORTING SEAS NEAR
14 FEET WITH A PERIOD AROUND 14 SECONDS THIS EVENING. THIS SWELL IS
PRODUCING DANGEROUS SURF CONDITIONS...AND HIGH SURF WARNINGS AND
ADVISORIES ARE IN EFFECT THROUGH TONIGHT. THE LARGE SEAS WILL LEAD
TO SMALL CRAFT ADVISORIES FOR MUCH OF THE REMAINING COASTAL WATERS
DUE TO HAZARDOUS SEAS ABOVE 10 FEET. LOOKS LIKE WARNINGS AND
ADVISORIES ARE GOOD FOR TONIGHT AND WILL RE-EXAMINE HIGHLIGHTS FOR
THE MORNING FORECAST PACKAGE BASED ON OBSERVATION TRENDS. AS OF
RIGHT NOW...LOOKING AT DOWN GRADING HIGH SURF WARNING AREAS TO
ADVISORIES FOR TUESDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF WARNING UNTIL 6 AM HST TUESDAY FOR NORTH AND WEST FACING
SHORES OF KAUAI AND NIIHAU AND FOR NORTH FACING SHORES OF OAHU
MOLOKAI AND MAUI.

HIGH SURF ADVISORY UNTIL 6 AM HST FOR WEST FACING SHORES OF OAHU AND
NORTH AND WEST FACING SHORES OF THE BIG ISLAND.

SMALL CRAFT ADVISORY UNTIL 6 PM HST TUESDAY FOR KAUAI NORTHWEST
WATERS-KAUAI WINDWARD WATERS-KAUAI LEEWARD WATERS-KAUAI CHANNEL-
OAHU WINDWARD WATERS-OAHU LEEWARD WATERS-KAIWI CHANNEL-MAUI
COUNTY WINDWARD WATERS-BIG ISLAND WINDWARD WATERS.

SMALL CRAFT ADVISORY UNTIL 6 AM HST TUESDAY FOR ALENUIHAHA
CHANNEL-BIG ISLAND SOUTHEAST WATERS.

&&

FOSTER