Alert archive / Hawaii / Flash Flood Warnings in 2011

Flash Flood Warning 19, NWS Honolulu, HI

May 2, 2011Honolulu County, Hawaii

NWS Honolulu, HI issued this flash flood warning at May 2, 2011, 6:09 PM HST for Honolulu County, Hawaii. It was in force for 3 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: May 2, 2011, 6:09 PM HST (04:09 UTC)
Expired: May 2, 2011, 9:00 PM HST
In force: 3 hr
Issued by: NWS Honolulu, HI
Area: Storm-based polygon
Flood severity: None

County Honolulu County, HI

The radar

The Molokai radar (PHMO), 89 km from the middle of the area, began a volume at 04:11 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

Time	Report	Where	Remark
May 2, 6:30 PM HST	FLASH FLOOD	Waianae, HI	PLANTATION ROAD CLOSED DUE TO A DOWNED POWER LINE.
May 2, 7:30 PM HST	FLASH FLOOD	1 S Makiki, HI	NUMEROUS CARS INUNDATED BY FLOODING ON NANEA STREET.

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, 4.2 hours before the alert went out and 154 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1270 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 846 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 83 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

451 
WGHW50 PHFO 030409
FFWHFO
HIC003-030700-
/O.NEW.PHFO.FF.W.0019.110503T0409Z-110503T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HONOLULU HI
609 PM HST MON MAY 2 2011

THE NATIONAL WEATHER SERVICE IN HONOLULU HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  THE ISLAND OF OAHU IN HONOLULU COUNTY

* UNTIL 900 PM HST

* AT 601 PM HST...RADAR SHOWED HEAVY RAIN NEAR WAIAHOLE...OR ABOUT 11
  MILES NORTH OF HONOLULU. THE AREA OF HEAVY RAIN WAS NEARLY
  STATIONARY WITH THE HEAVIEST RAIN OVER THE KOOLAU MOUNTAINS. THE 
  RAIN GAGE AT NUUANU JUST REPORTED A RAINFALL RATE OF OVER 2 INCHES 
  PER HOUR.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  KAHALUU...PUNALUU...WAIKANE...WAIALUA...WAHIAWA...SCHOFIELD
  BARRACKS...LAIE...KAHUKU...HAUULA AND HALEIWA.

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 FLASH FLOOD WARNING REPLACES THE FLOOD ADVISORY THAT WAS IN
EFFECT FOR THE ISLAND OF HONOLULU COUNTY.

THIS WARNING MAY NEED TO BE EXTENDED BEYOND 900 PM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2157 15829 2173 15797 2145 15771 2127 15764
      2124 15781 2129 15811

$$
DONALDSON

3 follow-up statements

669 
WGHW70 PHFO 030500
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
700 PM HST MON MAY 2 2011

HIC003-030700-
/O.CON.PHFO.FF.W.0019.000000T0000Z-110503T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HONOLULU COUNTY-
700 PM HST MON MAY 2 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE ISLAND OF OAHU IN
HONOLULU COUNTY UNTIL 900 PM HST...

RADARS SHOW WIDESPREAD HEAVY RAIN AND THUNDERSTORMS CONTINUING OVER 
OAHU. AT 645 PM THE RAIN GAGE AT MANOA LYON ARBORETUM RECORDED RAIN 
FALLING AT 3 INCHES PER HOUR. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PUNALUU...
WAIKANE...WAIALUA...WAHIAWA...SCHOFIELD BARRACKS...LAIE...KAHUKU...
HAUULA AND HALEIWA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS FLASH FLOODING IS IMMINENT OR OCCURRING
IN STREAMS...ROADS AND LOW LYING AREAS. IF YOU ARE IN AN AREA WHERE 
THE WATER IS RISING RAPIDLY...MOVE TO HIGHER GROUND IMMEDIATELY.

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

IF YOU ARE IN A SAFE LOCATION...STAY PUT.

&&

THIS WARNING MAY NEED TO BE EXTENDED BEYOND 900 PM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2157 15829 2173 15797 2145 15771 2127 15764
      2124 15781 2129 15811

$$
DONALDSON

911 
WGHW70 PHFO 030604
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
804 PM HST MON MAY 2 2011

HIC003-030700-
/O.CON.PHFO.FF.W.0019.000000T0000Z-110503T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HONOLULU COUNTY-
804 PM HST MON MAY 2 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE ISLAND OF OAHU IN
HONOLULU COUNTY UNTIL 900 PM HST...

RAINFALL OVER OAHU HAS DIMINISHED BUT RUNOFF WILL CONTINUE FOR A 
WHILE. EMERGENCY OFFICIALS REPORT THAT ROYAL HAWAIIAN AVENUE 
REMAINS CLOSED DUE TO FLOODING. KALAKAUA AVENUE IN WAIKIKI WAS 
CLOSED DUE TO WATER BUT HAS RECENTLY RE-OPENED. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PUNALUU...
WAIKANE...WAIALUA...WAHIAWA...SCHOFIELD BARRACKS...LAIE...KAHUKU...
HAUULA AND HALEIWA.

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.

AVOID TRAVEL UNTIL THE FLOODING HAS ENDED.

&&

THIS WARNING MAY NEED TO BE EXTENDED BEYOND 900 PM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2157 15829 2173 15797 2145 15771 2127 15764
      2124 15781 2129 15811

$$
DONALDSON

407 
WGHW70 PHFO 030652
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
852 PM HST MON MAY 2 2011

HIC003-030702-
/O.EXP.PHFO.FF.W.0019.000000T0000Z-110503T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HONOLULU COUNTY-
852 PM HST MON MAY 2 2011

...THE FLASH FLOOD WARNING HAS EXPIRED FOR THE ISLAND OF HONOLULU
COUNTY...

WEATHER RADAR SHOWS THAT HEAVY RAINFALL HAS MOVED OFFSHORE. THUS THE
FLASH FLOOD WARNING IS ALLOWED TO EXPIRE.

LAT...LON 2157 15829 2173 15797 2145 15771 2127 15764
      2124 15781 2129 15811

$$
DONALDSON

The office that day

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

Issued	Product	Office	Counties	Lasted
May 2, 2:43 PM HST	Areal Flood Advisory	HFO	Hawaii	86 min
May 2, 2:51 PM HST	Areal Flood Advisory	HFO	Kalawao	3 hr
May 2, 3:35 PM HST	Areal Flood Advisory	HFO	Kalawao	3 hr
May 2, 3:39 PM HST	Areal Flood Advisory	HFO	Kalawao	3 hr
May 2, 3:54 PM HST	Areal Flood Advisory	HFO	Honolulu	3 hr
May 2, 4:24 PM HST	Areal Flood Advisory	HFO	Kalawao	112 min
May 2, 5:11 PM HST	Areal Flood Advisory	HFO	Kalawao	64 min
May 2, 5:46 PM HST	Special Marine Warning	HFO		16 min
May 2, 5:52 PM HST	Special Marine Warning	HFO		37 min
May 2, 6:34 PM HST	Special Marine Warning	HFO		41 min
May 3, 12:52 AM HST	Areal Flood Advisory	HFO	Honolulu	85 min
May 3, 4:06 AM HST	Flash Flood Warning	HFO	Kauai	54 min
May 3, 6:56 AM HST	Areal Flood Advisory	HFO	Honolulu	105 min
May 3, 9:45 AM HST	Small Craft Advisory	HFO		4 days
May 3, 12:35 PM HST	Areal Flood Advisory	HFO	Hawaii	3 hr

Nearby

Flash Flood Warnings in Hawaii, 2011 Every flash flood warning in 2011

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.