Flash Flood Warning 18, NWS Honolulu, HI

487 
WGHW70 PHFO 240614
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
814 PM HST SUN AUG 23 2015

HIC001-240620-
/O.EXP.PHFO.FF.W.0018.000000T0000Z-150824T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HAWAII HI-
814 PM HST SUN AUG 23 2015

...THE FLASH FLOOD WARNING HAS EXPIRED FOR THE ISLAND OF HAWAII IN
HAWAII COUNTY...

WEATHER RADAR SHOWED THAT THE AREAS OF HEAVY RAINFALL HAVE MOVED 
OFFSHORE. CIVIL DEFENSE AND OTHER AUTHORITIES ON THE BIG ISLAND 
INDICATED THAT NO ADDITIONAL IMPACTS HAVE BEEN REPORTED ON THE 
WARNED AREA. THUS THE FLASH FLOOD WARNING IS ALLOWED TO EXPIRE.

THE HEAVY RAINS AND FLOODING HAVE SUBSIDED...BUT RUNOFF IS STILL
OCCURRING AND STREAMS WILL REMAIN HIGH FOR SEVERAL HOURS.

A FLASH FLOOD WATCH FOR THE BIG ISLAND OF HAWAII REMAINS IN
EFFECT UNTIL 6 PM HST MONDAY.

LAT...LON 2025 15593 2029 15584 2021 15571 2010 15544
      1999 15559 2003 15584 2010 15590

$$

REYNES

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
335 PM HST SUN AUG 23 2015

.SYNOPSIS...
DEEP TROPICAL MOISTURE WILL REMAIN OVER THE ISLANDS FOR THE NEXT
SEVERAL DAYS...THEREBY FUELING LOCALLY HEAVY SHOWERS AND
THUNDERSTORMS...AND A FLASH FLOOD WATCH REMAINS IN EFFECT FOR ALL
ISLANDS. LIGHT WINDS WILL FAVOR A SOUTHEASTERLY DIRECTION FOR THE
NEXT SEVERAL DAYS...WITH LIGHT TO MODERATE TRADE WINDS EXPECTED TO
RETURN DURING THE SECOND PART OF THE WEEK. EVEN WHEN TRADE WINDS
RETURN...THE ATMOSPHERE WILL REMAIN QUITE MOIST. ALTHOUGH THE LATEST
FORECAST FROM THE CENTRAL PACIFIC HURRICANE CENTER KEEPS THE CENTER
OF KILO SEVERAL HUNDRED MILES WEST OF KAUAI LATER THIS WEEK...YOU
SHOULD CONTINUE TO MONITOR THE LATEST FORECASTS FOR POTENTIAL
CHANGES.

&&

.DISCUSSION...
ALTHOUGH TROPICAL CYCLONE KILO IS CENTERED WELL SW OF THE ISLANDS...
SOUTHERLY FLOW TO THE E OF THE SYSTEM HAS DRAGGED A VERY MOIST AND
UNSTABLE AIR MASS OVER THE ISLANDS AND SURROUNDING WATERS. WITH WEAK
TROUGHING ALOFT JUST N OF THE AREA...THE AIR MASS IS UNSTABLE...
SUPPORTING HEAVY SHOWERS AND THUNDERSTORMS. WITH SURFACE DEW POINTS
IN THE MID TO UPPER 70/S...IT IS EXTREMELY MUGGY OUTSIDE AND THUS
SWEAT DOES NOT EVAPORATE AS QUICKLY...THEREBY PREVENTING THE BODY
FROM RELEASING HEAT QUICKLY. IF PARTICIPATING IN STRENUOUS OUTDOOR
ACTIVITIES THE NEXT COUPLE OF DAYS...BE SURE TO DRINK PLENTY OF
NON-ALCOHOLIC FLUIDS. ALSO IF VENTURING OUTDOORS...BE AWARE OF THE
DANGERS POSED BY CLOUD TO SURFACE LIGHTNING STRIKES...AND REMEMBER
THAT LIGHTNING CAN STRIKE EVEN IF IT IS NOT RAINING AT YOUR
LOCATION. IF THUNDER ROARS...GO INDOORS.

THE SYNOPTIC SITUATION FEATURES THE LOW PRESSURE ASSOCIATED WITH
KILO SEVERAL HUNDRED MILES SW OF THE ISLANDS...AND A SURFACE HIGH
CENTERED FAR N OF THE AREA...NEAR THE ALEUTIAN ISLANDS. THE GRADIENT
BETWEEN THESE FEATURES IS SUPPORTING A LIGHT SE FLOW OVER THE AREA.
A WEAK SURFACE LOW IS FORECAST TO BE LOCATED BETWEEN THE ISLANDS AND
THE HIGH OVER THE NEXT SEVERAL DAYS...THUS LITTLE CHANGE IN THE
OVERALL WIND PATTERN IS EXPECTED THROUGH WEDNESDAY. WEAK TROUGHING
ALOFT WILL PERSIST JUST N OF THE AREA...AND COMBINED WITH THE DEEP
MOISTURE...HEAVY SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE
THROUGH ABOUT MID-WEEK. ALTHOUGH THE OFFICIAL FORECAST FROM THE
CENTRAL PACIFIC HURRICANE CENTER BRINGS KILO CLOSER TO THE W END
OF THE CHAIN LATE IN THE WEEK...THUS FAR IT IS NOT EXPECTED TO
LEAD TO INCREASED WINDS OVER THE AREA.

MOISTURE OVER THE AREA IS EXPECTED TO DIMINISH SOMEWHAT AROUND
THURSDAY AND FRIDAY...BUT A WEAK TROUGH ALOFT IS FORECAST TO EXTEND
OVER THE AREA FROM THE NE AS NEXT WEEKEND APPROACHES. THE HIGH TO
THE N WILL REMAIN QUITE DISTANT...AND WITH KILO FORECAST BY CPHC TO
BE W OF THE AREA...A LIGHT TRADE WIND FLOW IS EXPECTED FROM ABOUT
MID-WEEK INTO NEXT WEEKEND. THUS CLOUDS AND SHOWERS ARE EXPECTED TO
FAVOR WINDWARD AND MAUKA AREAS...BUT WINDS MAY BE LIGHT ENOUGH TO
ALLOW AFTERNOON SEA BREEZES TO DRIVE CLOUD AND SHOWER DEVELOPMENT
OVER LEEWARD SLOPES AND COASTS.

ALL INTERESTS IN THE STATE OF HAWAII SHOULD CLOSELY FOLLOW THE
PROGRESS OF KILO BY MONITORING THE LATEST BULLETINS AND PRODUCTS
ISSUED BY THE CENTRAL PACIFIC HURRICANE CENTER AND THE NATIONAL
WEATHER SERVICE OFFICE IN HONOLULU.

&&

.AVIATION...
OUR VERY MOIST AND UNSTABLE AIRMASS MAY PRODUCE HEAVY SHOWERS AND
THUNDERSTORMS ANYWHERE ACROSS THE AREA THROUGH TONIGHT. VFR IS
FORECAST TO DOMINATE AT THE TERMINALS...BUT MVFR AND IFR CONDITIONS
COULD OCCUR ELSEWHERE WITHIN DEEP CONVECTION. AIRMET SIERRA IS IN
EFFECT OVER WINDWARD AND SOUTHEAST FACING BIG ISLAND SLOPES FOR
OCCASIONAL MOUNTAIN OBSCURATION ABOVE 1000 FEET DUE TO DEVELOPING
SHOWERS AND THUNDERSTORMS....AND MAY HAVE TO BE EXPANDED AS ADVERSE
WEATHER SPREADS INTO THIS EVENING.

&&

.MARINE...
A SMALL TO MODERATE W SWELL WILL CONTINUE OVER THE ISLANDS THROUGH
THE MIDDLE OF THE WEEK. A SLIGHTLY LARGER VERY LONG PERIOD WNW
SWELL...GENERATED BY DISTANT TYPHOON ATSANI...IS EXPECTED TO ARRIVE
AROUND WEDNESDAY...PEAKING THURSDAY INTO FRIDAY. THIS SWELL...WITH
OPEN OCEAN SWELL HEIGHTS EXPECTED TO BE AROUND 4-5 FEET...MAY BE
LARGE ENOUGH TO BRING ADVISORY LEVEL SURF TO THE W FACING SHORES OF
THE BIG ISLAND.

MARINERS MAY ENCOUNTER HEAVY SHOWERS OR THUNDERSTORMS AS A VERY
MOIST AND UNSTABLE AIR MASS REMAINS ACROSS THE AREA THROUGH THE NEXT
COUPLE OF DAYS. A MARINE WEATHER STATEMENT IS IN EFFECT TO HIGHLIGHT
THE THREAT TO MARINERS.

WITH THE PRESENCE OF KILO NEARBY...SMALL CHANGES IN THE TRACK OR
INTENSITY OF THIS SYSTEM MAY LEAD TO BIG CHANGES IN THE FORECAST FOR
THE COASTAL WATERS AS WELL AS THE POTENTIAL FOR ROUGH SURF FOR THE
ISLANDS LATER THIS WEEK. MARINERS SHOULD MONITOR FORECASTS FOR THE
LATEST UPDATES BEFORE HEADING OUT...ESPECIALLY IF PLANNING TRIPS TO
THE OFFSHORE WATERS.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH 6 PM HST MONDAY FOR ALL ISLANDS.

&&

DISCUSSION/MARINE...BIRCHARD
AVIATION...POWELL