Alert archive / Hawaii / Flash Flood Warnings in 2017

Flash Flood Warning 21, NWS Honolulu, HI

October 31, 2017Kauai County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Oct 31, 2017, 5:28 PM HST for Kauai County, Hawaii. It was in force for 3 hr. 1 report 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
Oct 31, 2017, 5:28 PM HST (03:28 UTC)
Expired
Oct 31, 2017, 8:30 PM HST
In force
3 hr
Issued by
NWS Honolulu, HI
Area
Storm-based polygon
Flood severity
None

County Kauai County, HI

The radar

The South Kauai radar (PHKI), 31 km from the middle of the area, began a volume at 03:30 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
Oct 31, 6:30 PM HSTFLOODHanalei, HIKAUAI EMERGENCY MANAGEMENT AGENCY REPORTS THAT KUHIO HIGHWAY AT THE HANALEI BRIDGE IS CLOSED TO ROAD FLOODING.

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

The nearest sounding before it

Lihue, (PHLI), launched 00:00Z, 3.5 hours before the alert went out and 23 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 00:00Z on 2017-11-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2148 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lihue, at 00:00Z on 2017-11-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 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
2148 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
651 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.6

Open this sounding in Storm Lab

The text

As transmitted.

173 
WGHW50 PHFO 010328
FFWHFO
HIC007-010630-
/O.NEW.PHFO.FF.W.0021.171101T0328Z-171101T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash FLood Warning
National Weather Service Honolulu HI
528 PM HST TUE OCT 31 2017

The National Weather Service in Honolulu has issued a

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

* Until 830 PM HST

* At 526 PM HST, Hanalei Stream gage indicates flash flooding will 
  likely occur in the next hour. Rain was falling across the island 
  of Kauai at a rate of 1 to 2 inches per hour.

* Locations in the warning include but are not limited to...
  Kilauea, Anahola, Hanalei, Na Pali State Park, Wainiha, North Fork
  Wailua Trails, Moloaa, Princeville, Haena, Kokee State Park, Wailua
  Homesteads and Kapaa.

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 830 PM HST if heavy rain
persists.

This flash flood warning replaces the previously issued flood
advisory that was in effect for portions of the island of Kauai in
Kauai County.

LAT...LON 2221 15934 2215 15930 2208 15931 2196 15952
      2210 15975 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Foster
2 follow-up statements
587 
WGHW70 PHFO 010436
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
636 PM HST TUE OCT 31 2017

HIC007-010630-
/O.CON.PHFO.FF.W.0021.000000T0000Z-171101T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
636 PM HST TUE OCT 31 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM HST FOR THE
ISLAND OF KAUAI IN KAUAI COUNTY...

At 630 PM HST, Kauai Emergency Management Agency reported water 
rising over Kuhio Highway at the Hanalei River, with the road in the 
process of being closed. Radar indicates areas of light to moderate 
rain continuing over parts of the island of Kauai, with a general 
decrease in rainfall intensity observed during the past hour.

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 830 PM HST if heavy rain
persists.

LAT...LON 2221 15934 2215 15930 2208 15931 2196 15952
      2210 15975 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Jacobson
137 
WGHW70 PHFO 010631
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
831 PM HST TUE OCT 31 2017

HIC007-010638-
/O.EXP.PHFO.FF.W.0021.000000T0000Z-171101T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kauai HI-
831 PM HST TUE OCT 31 2017

...THE FLASH FLOOD WARNING FOR THE ISLAND OF KAUAI IN KAUAI COUNTY
WILL EXPIRE AT 830 PM HST...

Weather radar showed that the earlier heavy rains have ended across 
Kauai, and the flash flood warning will be allowed to expire. Kauai 
Emergency Management Agency reports that water is slowly receding on 
the Kuhio Highway at Hanalei Bridge, but the road remains closed at 
this time.

A flash flood watch remains in effect for Kauai through Wednesday, 
and additional heavy rains may develop at any time. Continue to 
monitor weather conditions and be prepared to take action should 
additional warnings be issued.

LAT...LON 2221 15934 2215 15930 2208 15931 2196 15952
      2210 15975 2216 15971 2223 15956 2221 15950
      2223 15949 2222 15943 2224 15940

$$

Jacobson

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 31, 2:06 PM HSTAreal Flood AdvisoryHFOKauai6 hr
Oct 31, 3:50 PM HSTHigh Surf AdvisoryHFOKauai24 hr
Nov 1, 4:02 AM HSTAreal Flood AdvisoryHFOKauai6 hr
Nov 1, 7:14 AM HSTFlash Flood WarningHFOKauai3 hr
Nov 1, 9:55 AM HSTFlash Flood WarningHFOKauai4 hr

Nearby

Flash Flood Warnings in Hawaii, 2017Every flash flood warning in 2017

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.