Flash Flood Warning 29, NWS Honolulu, HI

859 
WGHW70 PHFO 251240
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
240 AM HST TUE AUG 25 2015

HIC007-251400-
/O.CON.PHFO.FF.W.0029.000000T0000Z-150825T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KAUAI HI-
240 AM HST TUE AUG 25 2015

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE ISLAND OF KAUAI IN
KAUAI COUNTY UNTIL 400 AM HST...

A LINE OF HEAVY SHOWERS MOVED ASHORE ALONG THE WEST COAST OF KAUAI 
BETWEEN POLIHALE AND BARKING SANDS...MERGING WITH THE SHOWERS 
ALREADY PRESENT OVER THE ISLAND. RADAR DATA SHOWED LARGE AREAS OF 
RAIN RATES BETWEEN 3 AND 4 INCHES AN HOUR...AND SMALLER AREAS OF 4 
TO 6 INCHES AN HOUR.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MANA...
WAILUA...KOKEE STATE PARK...KAPAA AND ANAHOLA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS FLASH FLOODING IS IMMINENT OR OCCURRING
IN STREAMS...ROADS AND LOW LYING AREAS. MOVE TO HIGHER GROUND NOW.

DO NOT CROSS FAST FLOWING OR RISING WATER IN YOUR VEHICLE OR ON FOOT.
TURN AROUND...DON/T DROWN.

&&

THIS WARNING MAY NEED TO BE EXTENDED BEYOND 400 AM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2216 15984 2216 15923 2186 15934 2190 15983

$$

189 
WGHW70 PHFO 251354
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
354 AM HST TUE AUG 25 2015

HIC007-251356-
/O.CAN.PHFO.FF.W.0029.000000T0000Z-150825T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KAUAI HI-
354 AM HST TUE AUG 25 2015

...THE FLASH FLOOD WARNING IS CANCELLED FOR THE ISLAND OF KAUAI IN
KAUAI COUNTY...

WEATHER RADAR AND RAIN GAGES SHOWED THAT THE HEAVY RAINS HAVE 
ENDED...BUT RUNOFF IS STILL OCCURRING AND STREAMS WILL REMAIN HIGH 
FOR SEVERAL HOURS.

A FLASH FLOOD WATCH REMAINED IN EFFECT FOR THE STATE OF HAWAII.

LAT...LON 2216 15984 2216 15923 2186 15934 2190 15983

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST MON AUG 24 2015

.SYNOPSIS...
EXTREMELY HUMID CONDITIONS WILL KEEP SHOWERS HEAVIER THAN USUAL OVER
THE ISLANDS THROUGH MOST OF THE WEEK. LIGHT WINDS WILL YIELD TO
MODEST TRADE WINDS BY THE WEEKEND...AND THEY MAY START TO BRING IN
DRIER AIR...BUT UNSETTLED CONDITIONS APPEAR LIKELY TO RETURN BY
EARLY NEXT WEEK.

&&

.DISCUSSION...
THE HUGE AREAS OF CONVECTION AROUND THE STATE FROM SUNDAY AND THIS
MORNING LARGELY HAD DISSIPATED...THOUGH LIGHTNING DETECTORS STILL
REGISTERED A FEW STRIKES OVER THE OFFSHORE WATERS TO THE SOUTHWEST
OF THE BIG ISLAND. TOWERING CUMULI ALSO PERCOLATED WELL TO THE
NORTH-NORTHWEST OF THE STATE...PROBABLY UNDER THE INFLUENCE OF A
SHALLOW TROUGH ALOFT TO THE NORTHWEST THROUGH NORTH.

THE AIR MASS REMAINED UNSEASONABLY MOIST...EVEN IN A TYPICALLY HUMID
SEASON...BUT MIXING AND RAIN-OUT HAD DRIED PRECIPITABLE WATER TO
BELOW TWO INCHES AT LIHUE. THE HILO SOUNDING STILL SHOWED ALMOST TWO
AND A HALF INCHES. MOST OF THE EXTENSIVE CLOUD COVER CONSISTED OF
DEBRIS LAYERS FROM EARLIER CONVECTION. IF IT LASTS LONG ENOUGH...
THIS SHROUD SHOULD HELP TO LIMIT AFTERNOON TEMPERATURES AND DIURNAL
BUILDUPS DURING THE NEXT COUPLE OF DAYS...BUT IT ALSO WILL REDUCE
COOLING AT NIGHT...SO CONDITIONS WILL REMAIN UNCOMFORTABLY WARM.

GUIDANCE PREDICTED THE SURFACE RIDGE TO THE NORTH TO REMAIN WEAK
THROUGH WEDNESDAY OR THURSDAY...AND THE RESULTING LIGHT SOUTHEAST
FLOW HAD LITTLE OPPORTUNITY TO BRING A CHANGE OF AIR MASS THROUGH
THIS PERIOD. BY FRIDAY...SOLUTIONS LEANED TOWARD REBUILDING THE
RIDGE...BRINGING BACK SOMETHING LIKE TRADE WINDS BY THE WEEKEND.
DRIER AIR WILL TAKE SOME TIME TO ADVECT IN HOWEVER...AND THE TRADE
WINDS SIMPLY MAY NOT HAVE ENOUGH TIME.

MOST SOLUTIONS NOW INCLUDED YET ANOTHER TROPICAL CYCLONE APPROACHING
THE STATE FROM THE SOUTHEAST BY EARLY NEXT WEEK. IT WAS MUCH TOO
EARLY TO SPECULATE ABOUT THE EFFECTS OF THE MAIN FEATURE...BUT THE
MOISTURE SURGE ACCOMPANYING THE CYCLONE MAY PRODUCE SIGNIFICANT
EFFECTS ANYWAY...AS THE EVENTS OF THE LAST 36 HOURS DEMONSTRATED.
MANY MODELS PREDICTED THE TROUGH ALOFT TO DIG TOWARD THE ISLANDS
OVER THE WEEKEND AS WELL. THUS...EARLY NEXT WEEK MAY WELL START WITH
ANOTHER BOUT OF CONVECTION.

&&

.MARINE...
A SMALL TO MODERATE W SWELL WILL CONTINUE AROUND THE ISLANDS THROUGH
THE MIDDLE OF THE WEEK. A SLIGHTLY LARGER VERY LONG-PERIOD WNW SWELL
FROM DISTANT TYPHOON ATSANI IS EXPECTED TO ARRIVE WEDNESDAY...AND
THEN TO PEAK THURSDAY INTO FRIDAY. THIS SWELL MAY BE LARGE ENOUGH
TO PRODUCE ADVISORY-LEVEL SURF ALONG WEST-FACING SHORES OF THE BIG
ISLAND.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY AFTERNOON FOR NIIHAU-KAUAI-
OAHU-MOLOKAI-LANAI-MAUI-BIG ISLAND.

&&

RYSHKO