Severe Thunderstorm Warning 3, NWS Honolulu, HI

179 
WWHW50 PHFO 032358
SVSHFO

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
158 PM HST THU MAR 3 2011

HIC007-040005-
/O.EXP.PHFO.SV.W.0003.000000T0000Z-110304T0000Z/
KAUAI IN KAUAI-
158 PM HST THU MAR 3 2011

...SEVERE THUNDERSTORM WARNING FOR KAUAI EXPIRES AT 200 PM HST...

THE STORM THAT PROMPTED THE SEVERE THUNDERSTORM WARNING HAS MOVED
OFFSHORE...AND THE SEVERE THUNDERSTORM WARNING WILL BE ALLOWED TO
EXPIRE AT 200 PM.

LAT...LON 2247 15957 2235 15937 2198 15965 2208 15981
TIME...MOT...LOC 2355Z 212DEG 30KT 2227 15958

$$
R BALLARD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1022 AM HST THU MAR 3 2011

.SYNOPSIS...
A DEVELOPING LOW PRESSURE SYSTEM WILL PASS NORTH OF KAUAI TONIGHT...
BRINGING HEAVY RAINFALL AND GUSTY SOUTHWEST WINDS...ESPECIALLY TO
KAUAI AND OAHU. THE LOW WILL BRING A FRONT TO KAUAI AND OAHU ON
FRIDAY...WITH THE FRONT MOVING TO MAUI COUNTY ON SATURDAY...AND
THE BIG ISLAND ON SUNDAY...BEFORE DISSIPATING ON MONDAY. BREEZY
NORTHEAST WINDS WILL FOLLOW THE FRONT...WITH TRADE WINDS RETURNING
BY SUNDAY...AND CONTINUING FOR MOST OF NEXT WEEK.

&&

.DISCUSSION...
CURRENTLY...HIGH PRESSURE CENTERED FAR ENE OF THE ISLANDS HAS AN
ASSOCIATED RIDGE THAT EXTENDS WSW TO WATERS S OF THE BIG ISLAND...
WHILE A COMPLEX AREA OF LOW PRESSURE EXISTS JUST WNW OF KAUAI. THIS
SYNOPTIC SITUATION HAS LED TO INCREASED S WINDS NEAR KAUAI THIS
MORNING...WITH RADAR DETECTING NUMEROUS SHOWERS OVER KAUAI AND
SURROUNDING WATERS...AND OVER WATERS W OF OAHU. A TROUGH ALOFT IS
NOTED ON WATER VAPOR IMAGERY...ABOUT 600 MILES WEST OF KAUAI...BUT
IT/S EFFECTS ARE ALREADY BEING FELT...IN THE FORM OF INCREASED WINDS
OVER THE SUMMITS AND UPPER ELEVATIONS OF THE BIG ISLAND...WHERE A
HIGH WIND WARNING IS NOW IN EFFECT. A HIGH WIND WATCH FOR THE SUMMIT
OF HALEAKALA REMAINS IN EFFECT FOR TONIGHT...AS THIS SAME TROUGH IS
EXPECTED TO BRING INCREASED WINDS THERE AS WELL.

THE FORECAST CALLS FOR A DEVELOPING SURFACE LOW...WITH SIGNIFICANT
SUPPORT ALOFT...TO PASS N OF KAUAI TONIGHT...AND TRACK ENE. THE
PASSAGE OF THE SURFACE LOW AND TROUGH ALOFT WILL BRING UNSETTLED
WEATHER TO KAUAI AND OAHU...WHERE A FLASH FLOOD WATCH REMAINS IN
EFFECT. THE LOW WILL PUSH A FRONT TOWARD KAUAI AND OAHU...WITH
INCREASING MOISTURE AND INSTABILITY AHEAD OF THE FRONT BRINGING THE
THREAT OF THUNDERSTORMS...SOME OF WHICH COULD PRODUCE STRONG AND
GUSTY WINDS. IN FACT...ISOLATED STRONG CELLS ARE NOTED OVER WATERS
BOTH TO THE NW...AND S...OF KAUAI. IN ADDITION...SYNOPTIC SCALE S
TO SW WINDS ARE EXPECTED TO INCREASE TO NEAR ADVISORY LEVELS OVER
THE LOWER ELEVATIONS OF KAUAI AND OAHU TONIGHT AND FRIDAY...
ESPECIALLY AS THEY ACCELERATE OVER THE N AND E SIDES OF THE ISLANDS.

THE FRONT...MARKED BY A WIND SHIFT FROM SW TO N...IS EXPECTED TO
PASS OVER KAUAI FRIDAY MORNING...AND OAHU FRIDAY AFTERNOON...MOVING
TO MAUI COUNTY FRIDAY NIGHT AND SATURDAY. THE FRONT SHOULD BE
GRADUALLY WEAKENING BY THAT TIME...BUT A SECONDARY SHORT WAVE TROUGH
ALOFT COULD RE-ACTIVATE THE BOUNDARY SATURDAY NIGHT INTO SUNDAY...
POSSIBLY INCREASING THE THREAT OF THUNDERSTORMS OVER WINDWARD MAUI
AND BIG ISLAND WATERS. LATEST GUIDANCE INDICATES LOW LEVEL MOISTURE
ASSOCIATED WITH THE FRONT WILL SPREAD TO WINDWARD BIG ISLAND ON
SUNDAY...WITH THE MOISTURE AXIS DISSIPATING ON MONDAY...AS LOW LEVEL
CONVERGENCE AND UPPER LEVEL SUPPORT WANE.

AS THE FRONT PASSES A PARTICULAR ISLAND...EXPECT A WIND SHIFT TO
THE N AND NE...AND A GRADUAL DRYING TREND. THESE BREEZY NE WINDS
WILL BE SUPPORTED BY HIGH PRESSURE PASSING N OF THE ISLANDS...WITH
THE HIGH TRACKING STEADILY E INTO EARLY NEXT WEEK. THUS BREEZY NE
WINDS AFTER THE FRONT WILL VEER TO THE E AND WEAKEN BY EARLY NEXT
WEEK...WITH TYPICAL TRADE WIND WEATHER TO START THE WEEK.
POTENTIALLY WETTER TRADE WIND WEATHER FOR LATER NEXT WEEK.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL OVER THE STATE FROM OAHU E TODAY. MVFR
CONDITIONS WITH OCCASIONAL MOUNTAIN OBSCURATION ARE EXPECTED TO
CONTINUE FOR KAUAI AS NUMEROUS SHOWERS DEVELOP AHEAD OF AN
APPROACHING COLD FRONT. ISOLATED HEAVY SHOWERS WILL BRING CEILINGS
AND VISIBILITIES BRIEFLY TO IFR CATEGORY THROUGH THE AFTERNOON OVER
KAUAI AND THE SURROUNDING COASTAL WATERS.

CONDITIONS WILL DETERIORATE TONIGHT AND EARLY FRIDAY FROM W TO
E AS THE COLD FRONT CONTINUES TO ADVANCE E...AND ADDITIONAL AIRMETS
FOR MOUNTAIN OBSCURATION MAY BE NEEDED FOR OAHU AND SOME PARTS OF
MAUI COUNTY. STRONG SW WINDS WILL LIKELY REQUIRE AN AIRMET FOR LOW
LEVEL TURBULENCE ACROSS MUCH OF THE STATE TO THE N AND E OF THE
MOUNTAIN RANGES. IN ADDITION...THE THREAT OF THUNDERSTORMS WILL
INCREASE OVER KAUAI AND OAHU THROUGH TONIGHT AND EARLY FRIDAY AS THE
AIRMASS DESTABILIZES.

&&

.MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT THROUGH FRIDAY FOR WATERS AROUND
KAUAI AND OAHU...AS WELL AS LEEWARD MAUI COUNTY COASTAL WATERS...DUE
TO THE INCREASING WINDS...AND COMBINED SEAS NEARING 10 FEET.

A GALE WARNING IS IN EFFECT TONIGHT AND FRIDAY FOR THE OFFSHORE
WATERS...AS GALE FORCE WINDS ARE EXPECTED IN ASSOCIATION WITH THE
DEVELOPING SURFACE LOW THAT TRACKS ACROSS THE N PORTION OF THE
OFFSHORE WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR NIIHAU-KAUAI-OAHU.

HIGH WIND WARNING UNTIL 6 PM HST FRIDAY FOR BIG ISLAND SUMMITS.

HIGH WIND WATCH FROM 6 PM HST THIS EVENING THROUGH FRIDAY
AFTERNOON FOR HALEAKALA SUMMIT.

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

&&

BIRCHARD