Alert archive / Hawaii / Flash Flood Warnings in 2018

Flash Flood Warning 34, NWS Honolulu, HI

April 15, 2018Kauai County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Apr 15, 2018, 2:09 AM HST for Kauai County, Hawaii. It was in force for 24 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Apr 15, 2018, 2:09 AM HST (12:09 UTC)
Expired
Apr 16, 2018, 1:45 AM HST
In force
24 hr
Issued by
NWS Honolulu, HI
Area
Storm-based polygon
Flood severity
None

County Kauai County, HI

The radar

The South Kauai radar (PHKI), 24 km from the middle of the area, began a volume at 12:08 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Apr 15, 4:00 AM HSTFLASH FLOODHaena, HIVISITORS IN THE HANALEI COLONY RESORT IN HAENA HAVE BEEN MOVED TO THE SECOND FLOOR DUE TO RISING WATER.
Apr 15, 4:00 AM HSTFLASH FLOODHanalei, HISTANDING WATER UP TO 8 FEET OVER THE HIGHWAY AND AREAS IN THE TOWN WAS COMPLETELY COVERING VEHICLES.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this flash flood warning; the first came 111 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Lihue, (PHLI), launched 12:00Z, 0.2 hours before the alert went out and 20 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lihue, at 12:00Z on 2018-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 493 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lihue, at 12:00Z on 2018-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
493 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
730 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
210 m²/s²
Significant tornado parameter
0.3
Supercell composite
5.9

Open this sounding in Storm Lab

The text

As transmitted.

360 
WGHW50 PHFO 151209
FFWHFO
HIC007-151445-
/O.NEW.PHFO.FF.W.0034.180415T1209Z-180415T1445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
209 AM HST SUN APR 15 2018

The National Weather Service in Honolulu has issued a

* Flash Flood Warning for...
  The island of Kauai in Kauai County

* Until 445 AM HST

* At 205 AM HST, radar indicated heavy showers and thunderstorms 
  continuing to develop over Kauai, especially over the northern 
  portion of the island between Kilauea and Haena. Rainfall rates of 
  2 to 4 inches per hour with locally higher amounts are occurring. 
  The Hanalei Stream remains elevated above the critical flood 
  stage. The Hanapepe and Wainiha Streams have also begun to rise 
  rapidly. The Kauai Emergency Management Agency earlier reported 
  that Kuhio Highway remained closed due to multiple landslides 
  between Princeville and Wainiha. This is a very dangerous 
  situation. Avoid unnecessary travel. 

* Locations in the warning include the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 445 AM HST if heavy rain
persists.

A flash flood watch remains in effect for Kauai through 6 AM HST 
Sunday.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Gibbs
15 follow-up statements
012 
WGHW50 PHFO 151438
FFWHFO
HIC007-151745-
/O.EXT.PHFO.FF.W.0034.000000T0000Z-180415T1745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
438 AM HST SUN APR 15 2018

The National Weather Service in Honolulu has extended the

* Flash Flood Warning for...
  The island of Kauai in Kauai County

* Until 745 AM HST

* At 437 AM HST, radar indicated heavy showers and thunderstorms 
  continuing to develop over Kauai, especially over the northern 
  portion of the island where a historical flooding event is taking 
  place. Rainfall rates of 2 to 4 inches per hour with locally 
  higher amounts continue. The Hanalei Stream remains elevated and 
  is nearing record levels. The Hanapepe and Halaulani streams have 
  also quickly spiked to flood stage and could continue to rise. The 
  Kauai Emergency Management Agency reported that Kuhio Highway 
  remains closed due to multiple landslides that have occurred 
  between Princeville and Wainiha. Standing water up to 8 feet was 
  reported in the towns and across highways within this area, which 
  is completely covering some vehicles. This is a very dangerous 
  situation that is expanding to other portions of the island. Avoid 
  unnecessary travel. 

* Locations in the warning include the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 745 AM HST if heavy rain
persists.

A flash flood watch remains in effect for Kauai through 6 PM HST 
today.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Gibbs
191 
WGHW70 PHFO 151549
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
549 AM HST SUN APR 15 2018

HIC007-151745-
/O.CON.PHFO.FF.W.0034.000000T0000Z-180415T1745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
549 AM HST SUN APR 15 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 AM HST FOR THE
ISLAND OF KAUAI IN KAUAI COUNTY...

At 544 AM HST...radar and rain gage data indicated that the heaviest 
rainfall has shifted eastward and is now over east and northeast 
Kauai. Rain rates of 4 to 5 inches per hour were recorded over the 
Wailua and upper Kapaa areas. Streams such as Anahola Stream and 
Kapaa Stream are expected to rise to damaging levels. North Kauai 
remains cutoff past Princeville with severe flooding from Hanalei to 
Wainiha.

THIS IS A VERY DANGEROUS SITUATION. AVOID UNNECESSARY TRAVEL OVER 
EAST AND NORTH KAUAI. 

This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 745 AM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
809 
WGHW50 PHFO 151738
FFWHFO
HIC007-152045-
/O.EXT.PHFO.FF.W.0034.000000T0000Z-180415T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
738 AM HST SUN APR 15 2018

The National Weather Service in Honolulu has extended the

* Flash Flood Warning for...
  The island of Kauai in Kauai County

* Until 1045 AM HST

* At 725 AM HST, radar showed that the size of heavy rainfall has 
  decreased but there were still areas with rates of 2 to 3 inches 
  per hour over the upper Kapaa and Wailua areas of east Kauai. 
  Access to areas west of Princeville remain cut off. Kapaa Stream 
  and Anahola Stream are out of bank and running very high. THIS IS 
  A VERY DANGEROUS AND LIFE THREATENING EVENT. AVOID UNNECESSARY 
  TRAVEL ESPECIALLY TO AREAS NORTH OF LIHUE. 

* This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 1045 AM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
233 
WGHW70 PHFO 151837
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
837 AM HST SUN APR 15 2018

HIC007-152045-
/O.CON.PHFO.FF.W.0034.000000T0000Z-180415T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
837 AM HST SUN APR 15 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 AM HST FOR
THE ISLAND OF KAUAI IN KAUAI COUNTY...

At 828 AM HST...radar showed that rainfall has diminished 
significantly with only a small area of rain along the coast near 
Princeville and a small line near Kapaa and Wailua. Runoff and 
flooding is still significant over north and east Kauai. There is no 
road access to locations west of Princeville. Kuhio Highway is also 
restricted to one lane near the Wailua Golf Course.

This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 1045 AM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
508 
WGHW50 PHFO 152034
FFWHFO
HIC007-152345-
/O.EXT.PHFO.FF.W.0034.000000T0000Z-180415T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
1034 AM HST SUN APR 15 2018

The National Weather Service in Honolulu has extended the

* Flash Flood Warning for...
  The island of Kauai in Kauai County

* Until 145 PM HST

* At 1027 AM HST, radar showed an area of moderate to heavy rainfall 
  moving northward over north Kauai. This is likely to cause a brief 
  spike in Hanalei River and delay the draw down in water levels. 
  Runoff elsewhere has been receding. Road access to locations west 
  of Princeville is not yet possible. Avoid unnecessary travel to 
  north Kauai.

* This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 145 PM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
223 
WGHW70 PHFO 152134
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
1134 AM HST SUN APR 15 2018

HIC007-152345-
/O.CON.PHFO.FF.W.0034.000000T0000Z-180415T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
1134 AM HST SUN APR 15 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 145 PM HST FOR THE
ISLAND OF KAUAI IN KAUAI COUNTY...

At 1127 AM HST...intense rainfall has redeveloped over the Hanalei 
and Wainiha River basins in the last hour. The highest rates of 3 to 
4 inches per hour were focused on the Hanalei River basin and 
another flood wave is likely headed toward Kuhio Highway. There is 
no road access west of Princeville. THIS CONTINUES TO BE A VERY 
DANGEROUS SITUATION, ESPECIALLY WITH COMPLETELY SATURATED 
CONDITIONS. AVOID UNNECESSARY TRAVEL TO NORTH KAUAI.

This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 145 PM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
532 
WGHW70 PHFO 152257
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
1257 PM HST SUN APR 15 2018

HIC007-152345-
/O.CON.PHFO.FF.W.0034.000000T0000Z-180415T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
1257 PM HST SUN APR 15 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 145 PM HST FOR THE
ISLAND OF KAUAI IN KAUAI COUNTY...

At 1250 PM HST...intense rainfall continues over north and east 
Kauai. Radar estimated rates of at least 4 to 5 inches per hour, 
most of which was over the Hanalei River basin. The Hanalei River 
gage stopped transmitting several hours ago but another large flood 
wave has probably reached Kuhio Highway. Road access west of 
Princeville is not possible and several communities are isolated due 
to washed out roads. THIS CONTINUES TO BE A VERY DANGEROUS AND LIFE 
THREATENING SITUATION. AVOID UNNECESSARY TRAVEL TO NORTH KAUAI.

This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 145 PM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
132 
WGHW50 PHFO 152334
FFWHFO
HIC007-160245-
/O.EXT.PHFO.FF.W.0034.000000T0000Z-180416T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
134 PM HST SUN APR 15 2018

The National Weather Service in Honolulu has extended the

* Flash Flood Warning for...
  The island of Kauai in Kauai County

* Until 445 PM HST

* At 128 PM HST, intense rainfall with rates at least 4 to 5 inches 
  per hour continued over north and east Kauai. The heaviest 
  rainfall has spread east and will produce a rapid and significant 
  rise in the Kapaa Stream and Wailua River water levels. This is in 
  addition to the severe flooding ongoing in Hanalei River. Road 
  access west of Princeville is not possible and several communities 
  are isolated due to washed out roads. THIS CONTINUES TO BE A VERY 
  DANGEROUS AND LIFE THREATENING SITUATION. AVOID UNNECESSARY TRAVEL 
  TO NORTH AND EAST KAUAI.

* This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 445 PM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
203 
WGHW70 PHFO 160050
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
250 PM HST SUN APR 15 2018

HIC007-160245-
/O.CON.PHFO.FF.W.0034.000000T0000Z-180416T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
250 PM HST SUN APR 15 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM HST FOR THE
ISLAND OF KAUAI IN KAUAI COUNTY...

At 244 PM HST...the Kauai Emergency Management Agency reported that 
the water level in Hanalei River is up to the base of the Hanalei 
Bridge. Heavy rainfall has moved off the Hanalei River basin but is 
still intense over east Kauai near Wailua and upper Kapaa. A rain 
gage in Wailua recently recorded rain rates of 3 to 4 inches per 
hour. East Kauai streams and rivers are running very high. Road 
access west of Princeville is not possible and several communities 
are isolated due to washed out roads. THIS CONTINUES TO BE A VERY 
DANGEROUS AND LIFE THREATENING SITUATION. AVOID UNNECESSARY TRAVEL 
IN NORTH AND EAST KAUAI.

This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 445 PM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
482 
WGHW70 PHFO 160155
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
355 PM HST SUN APR 15 2018

HIC007-160245-
/O.CON.PHFO.FF.W.0034.000000T0000Z-180416T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
355 PM HST SUN APR 15 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM HST FOR THE
ISLAND OF KAUAI IN KAUAI COUNTY...

At 348 PM HST...radar showed that heavy rainfall has moved 
southwestward with the most intense areas currently over southeast 
Kauai. Rain rates of 3 to 4 inches per hour were detected upslope 
from Lihue with heavy rainfall also over Kuhio Highway between Lihue 
and Kalaheo. Roads west of Princeville remain inaccessible and 
several communities are isolated due to washed out roads. THIS 
CONTINUES TO BE A VERY DANGEROUS AND LIFE THREATENING SITUATION. 
AVOID UNNECESSARY TRAVEL IN NORTH AND EAST KAUAI.

This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 445 PM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
260 
WGHW50 PHFO 160232
FFWHFO
HIC007-160545-
/O.EXT.PHFO.FF.W.0034.000000T0000Z-180416T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
432 PM HST SUN APR 15 2018

The National Weather Service in Honolulu has extended the

* Flash Flood Warning for...
  The island of Kauai in Kauai County

* Until 745 PM HST

* At 426 PM HST, radar showed that intense rainfall has shifted to 
  the southeast slopes of Kauai with rain rates of 3 to 4 inches per 
  hour. This rainfall will produce very high water levels in the 
  South Fork of Wailua River and in Huleia Stream near Lihue. Heavy 
  rainfall was also over Kuhio Highway between Lihue and Lawai. 
  Roads west of Princeville remain inaccessible and several 
  communities are isolated due to washed out roads. THIS CONTINUES 
  TO BE A VERY DANGEROUS AND LIFE THREATENING SITUATION. AVOID 
  UNNECESSARY TRAVEL.

* This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 745 PM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
036 
WGHW70 PHFO 160345
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
545 PM HST SUN APR 15 2018

HIC007-160545-
/O.CON.PHFO.FF.W.0034.000000T0000Z-180416T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
545 PM HST SUN APR 15 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM HST FOR THE
ISLAND OF KAUAI IN KAUAI COUNTY...

At 535 PM HST...radar showed that rainfall has diminished over 
Kauai. The remaining area of rain was over the south slopes of the 
island near Kalaheo with rates of less than an inch per hour. 
However, runoff levels remain high. The Kauai Emergency Management 
Agency reported that the Kaumualii Highway and Koloa Road junction 
is impassable due to flooding. Piko Road and Kua Road were also 
flooded. The water level in Hanalei River has been slowly dropping 
but Kuhio Highway at the Hanalei Bridge remains closed. 

This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 745 PM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Kodama
802 
WGHW50 PHFO 160536
FFWHFO
HIC007-160845-
/O.EXT.PHFO.FF.W.0034.000000T0000Z-180416T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
736 PM HST SUN APR 15 2018

The National Weather Service in Honolulu has extended the

* Flash Flood Warning for...
  The island of Kauai in Kauai County

* Until 1045 PM HST

* At 735 PM HST, radar indicated that rainfall has diminished in 
  intensity, with mainly light rainfall occurring over the interior 
  of the Island with rainfall rates less than a half inch per hour. 
  However, stream levels remain high and heavy runoff continues. The 
  Kauai Emergency Management Agency reported that one lane of 
  Kaumualii Highway remains closed between Piko Road and Kaloa Road 
  due to flooding. Additionally, Kuhio Highway remains inaccessible 
  between Princeville and Haena.

* This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 1045 PM HST if heavy rain
persists.

A flash flood watch remains in effect for Kauai through 6 AM HST 
Monday.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Jelsema
704 
WGHW50 PHFO 160838
FFWHFO
HIC007-161145-
/O.EXT.PHFO.FF.W.0034.000000T0000Z-180416T1145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
1038 PM HST SUN APR 15 2018

The National Weather Service in Honolulu has extended the

* Flash Flood Warning for...
  The island of Kauai in Kauai County

* Until 145 AM HST

* At 1035 PM HST, radar indicated that light to occasionally 
  moderate rain continues to fall primarily over windward and 
  interior sections of the island, with rainfall rates less than 
  half an inch per hour. Although conditions are slowly improving 
  and stream levels are trending downward, the Kauai Emergency 
  Management Agency reports that Kuhio Highway remains closed at the 
  Hanalei Bridge.

* This warning includes the entire island of Kauai.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A flash flood warning means that flooding is imminent or occurring in
streams, roads, and low lying areas. Move to higher ground now.

Do not cross fast flowing water in your vehicle, or on foot. Turn
around, don't drown.

&&

This warning may need to be extended beyond 145 AM HST if flooding 
persists.

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Jelsema
202 
WGHW70 PHFO 161140
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
140 AM HST MON APR 16 2018

HIC007-161145-
/O.EXP.PHFO.FF.W.0034.000000T0000Z-180416T1145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
140 AM HST MON APR 16 2018

...THE FLASH FLOOD WARNING FOR THE ISLAND OF KAUAI IN KAUAI COUNTY
WILL EXPIRE AT 145 AM HST...

Flood waters have receded, and are no longer expected to pose a 
threat to life or property. However, Kauai Emergency Management 
Agency reports that Kuhio Highway will remain closed in the vicinity 
of the Hanalei Bridge until damage can be inspected and declared 
safe for vehicular traffic.  

LAT...LON 2221 15934 2215 15930 2205 15934 2197 15933
      2188 15943 2191 15960 2189 15961 2202 15979
      2206 15979 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Jelsema

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Honolulu, HI wrote its last area forecast discussion before this flash flood warning went out at Apr 14, 8:42 PM HST, 5 hours 27 minutes earlier.

Area forecast discussion, Apr 14, 8:42 PM HST, 5 hours 27 minutes before
Area Forecast Discussion
National Weather Service Honolulu HI
842 PM HST Sat Apr 14 2018

.UPDATE...
No significant changes in the forecast are anticipated this
evening, as the previous forecast remains on track. The flash
flood watch remains in effect through 6 AM HST Sunday for all
islands and will likely be extended through Sunday in the 4 AM
HST package due to an upper level low, surface trough and plenty
of deep layer moisture in place.

&&

.SYNOPSIS...
Breezy, wet, and unstable conditions will continue through at
least tonight and possibly through the weekend. An upper level
low to the west of the state will tap deep moisture in the breezy
trade wind flow, maintaining the threat of heavy rain and
thunderstorms. While the primary flood threat will be across
windward slopes, all areas could experience heavy rainfall. As the
upper level low slowly moves away on Monday and Tuesday, the
breezy trade wind flow will gradually stabilize, causing typical
rainfall to focus along windward slopes. Breezy trade winds and
extensive high clouds will hold through much of the week, with
unsettled weather possible late in the work week.

&&

.DISCUSSION...
Wet and unstable conditions remain in place. An upper level low
parked several hundred miles west of Kauai is generating the
instability along with a shield of high clouds blanketing much of
the state. The afternoon soundings continued to show no
inversion, and recent satellite data revealed precipitable water
(PW) values holding in the 1.5 to 1.8 inch range, which is well
above the roughly 1.25 inch April normal. A strong surface high
passing far north of the state is driving the breezy and gusty
trades, while a subtle mid level trough appears to stretch from
northeast to southwest just west of Kauai. It is this subtle
trough that has been focusing heavy showers and thunderstorms over
the Garden Isle, where in excess of 3 inches of rain has been
measured at several north shore gauges in the past 6 hours. From
Oahu to Maui, moderate to briefly heavy showers have been largely
confined to windward slopes today. On the Big Island, more
persistent heavy showers and thunderstorms have been pulsing along
windward slopes, and leeward shower activity has been somewhat
subdued, probably due to high cloud cover.

The threat of heavy, flooding showers and thunderstorms in the
breezy trade wind flow will persist through at least tonight. The
subtle mid level trough near Kauai will drift westward, taking a
focusing mechanism for moisture away from the islands. However,
deep moisture will linger over the islands, and the GFS model is
showing a weak shortwave aloft passing over the entire state
tonight. This points toward a threat of continued heavy, flooding
rainfall and a chance of thunderstorms for mainly windward slopes.
That said, grounds are saturated in many locations, including
some leeward areas, and a Flash Flood Watch remains in effect for
all locations on all islands.

The upper level low will begin to drift westward on Sunday, but
unstable conditions will likely remain in place. The mid level
trough will creep west and northwest of Kauai, leaving a broad
area of convergence just north of the islands. High pressure to
the north will maintain breezy trade winds, which will focus
potentially heavy showers across windward slopes. That said,
heavy showers could form over the leeward Big Island and Maui
slopes during the afternoon. As a result, the Flash Flood Watch
may need to be extended, though confidence is not high enough to
do so at this time.

The atmosphere will gradually stabilize on Monday and Tuesday
locally breezy trade winds hold. The upper level low will slowly
fill and drift westward, bringing an increase in stability and
pulling the deepest moisture west of the islands. This will likely
result in a drying trend over leeward areas of most islands,
though moderate rainfall will persist over windward slopes. High
clouds will still hang around over most areas.

Some instability could return to the trade wind flow later in the
week. The GFS and ECMWF show the weakened upper trough to the
west being pushed back over the state on Thursday. If this occurs,
heavy showers and thunderstorms could again be possible, with
rainfall continuing to be focused along windward slopes.

&&

.AVIATION...
A complex weather pattern will continue tonight and tomorrow.
Locally breezy E to ENE trade winds will continue at the surface
through around 10-12 kft before veering out of the S. AIRMET TANGO
for low level turbulence is posted across the state. An upper
level low, providing instability, and ample moisture will
maintain wet conditions with scattered thunderstorms for the
state. The wettest conditions will remain along the windward and
mountain areas, where AIRMET SIERRA for mountain obscuration is
posted across windward areas on all islands and for all of Kauai.
MVFR to isol IFR CIGS/VIS can be expected.

AIRMET ZULU for tempo light ice in any layered clouds above the
freezing level is also posted.

&&

.MARINE...
A Small Craft Advisory (SCA) is in effect for all waters through
most of the weekend for seas and winds. Isolated thunderstorms
remain likely over the coastal waters through tonight, with
likelihood and coverage diminishing somewhat for Sunday, but still
a possibility.

A northwest swell peaked Saturday morning, and the nearshore
buoys continue to show diminishing wave energy. A High Surf
Advisory (HSA) remains through Sunday morning for north and west
facing shores. A small north swell is expected mid-week with a
moderate northwest swell building Thursday night. As trade winds
strengthen Sunday, surf along east facing shores will increase to
advisory levels with elevated east shore surf persisting into the
first half of next week. Otherwise, surf will remain small along
south facing shores, but new swells from the southern hemisphere
will produce a modest increase starting as early as Sunday.

See the Collaborative Surf Discussion for additional details on
surf and swell.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch until 6 AM Sunday for all Hawaii islands.

High Surf Advisory until 6 AM HST Sunday for north and west facing
shores of Niihau, Kauai, Oahu, and Molokai, and for north facing
shores of Maui and the Big Island.

High Surf Advisory until 6 PM HST Sunday for east facing shores
of Kauai, Oahu, Molokai, Maui, and the Big Island.

Small Craft Advisory for all waters.

&&

UPDATE...Gibbs
MARINE...Morrison
AVIATION...Eaton
REST OF DISCUSSION...Wroe

In the hours before

Local storm report, Apr 14, 10:55 PM HST, 3 hours 14 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HONOLULU HI
1055 PM HST SAT APR 14 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0200 PM     FLASH FLOOD      WAINIHA                 22.21N 159.54W
04/14/2018                   KAUAI              HI   EMERGENCY MNGR

            KUHIO HIGHWAY CLOSED BETWEEN WAIKOKO AND WAINIHA DUE TO
            LANDSLIDES

0234 PM     FLASH FLOOD      HAENA                   22.22N 159.57W
04/14/2018                   KAUAI              HI   EMERGENCY MNGR

            KUHIO HIGHWAY CLOSED NEAR HAENA BEACH PARK

0700 PM     FLASH FLOOD      HANALEI                 22.21N 159.50W
04/14/2018                   KAUAI              HI   EMERGENCY MNGR

            KUHIO HIGHWAY CLOSED

0800 PM     FLASH FLOOD      WAINIHA                 22.21N 159.54W
04/14/2018                   KAUAI              HI   EMERGENCY MNGR

            WAINIHA POWERHOUSE ROAD WASHED OUT

0800 PM     FLASH FLOOD      WAINIHA                 22.21N 159.54W
04/14/2018                   KAUAI              HI   EMERGENCY MNGR

            TWO HOMES DESTROYED ON WANIHA POWERHOUSE ROAD

&&

MORRISON
Special weather statement, Apr 15, 12:56 AM HST, 1 hour 13 minutes before
Special Weather Statement
National Weather Service Honolulu HI
1256 AM HST SUN APR 15 2018

HIZ024-025-151200-
Big Island North and East-South Big Island-
1256 AM HST SUN APR 15 2018

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT HAWAII IN HAWAII
COUNTY...

At 1255 AM HST, strong thunderstorms were clustered 11 miles
southeast of Pahoa, or 30 miles southeast of Hilo, moving northwest
at 10 mph.

Winds in excess of 30 mph are possible with this storm.

Locations impacted include...
Hawaiian Paradise Park, Pahoa, Orchidlands Estates, Kalapana, Leilani
Estates, Hawaiian Beaches, Ainaloa, Nanawale Estates, Kapoho and
Isaac Hale Beach Park.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 1950 15483 1948 15482 1934 15499 1932 15505
      1934 15512 1961 15495 1956 15489 1954 15482
      1951 15481
TIME...MOT...LOC 1055Z 114DEG 9KT 1935 15485

EATON

The office that day

Everything else NWS Honolulu, HI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 14, 2:43 PM HSTAreal Flood AdvisoryHFOKauai3 hr
Apr 14, 3:11 PM HSTAreal Flood AdvisoryHFOHawaii3 hr
Apr 14, 4:14 PM HSTSpecial Marine WarningHFO46 min
Apr 14, 4:56 PM HSTSpecial Marine WarningHFO49 min
Apr 14, 5:15 PM HSTFlash Flood WarningHFOKauai9 hr
Apr 14, 5:24 PM HSTAreal Flood AdvisoryHFOHawaii109 min
Apr 14, 5:42 PM HSTSpecial Marine WarningHFO93 min
Apr 14, 7:08 PM HSTSpecial Marine WarningHFO72 min
Apr 14, 10:37 PM HSTAreal Flood AdvisoryHFOHonolulu3 hr
Apr 14, 11:40 PM HSTSpecial Marine WarningHFO2 hr
Apr 15, 12:44 AM HSTSpecial Marine WarningHFO54 min
Apr 15, 12:56 AM HSTSpecial Weather StatementHFO64 min
Apr 15, 1:26 AM HSTSpecial Marine WarningHFO64 min
Apr 15, 1:50 AM HSTAreal Flood AdvisoryHFOHawaii3 hr
Apr 15, 2:24 AM HSTSpecial Marine WarningHFO96 min
Apr 15, 4:24 AM HSTAreal Flood AdvisoryHFOHonolulu55 min
Apr 15, 4:31 AM HSTFlash Flood WarningHFOHawaii3 hr
Apr 15, 4:43 AM HSTSpecial Marine WarningHFO44 min
Apr 15, 4:57 AM HSTSpecial Marine WarningHFO2 hr
Apr 15, 7:12 AM HSTFlash Flood WarningHFOHawaii3 hr
Apr 15, 8:06 AM HSTSpecial Marine WarningHFO84 min
Apr 15, 9:24 AM HSTSpecial Marine WarningHFO37 min
Apr 15, 12:01 PM HSTSpecial Weather StatementHFOKauai59 min
Apr 15, 1:01 PM HSTSpecial Weather StatementHFOKauai59 min
Apr 15, 1:57 PM HSTSpecial Weather StatementHFOKauai93 min

Nearby

Flash Flood Warnings in Hawaii, 2018Every flash flood warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.