Alert archive / Hawaii / Flash Flood Warnings in 2015

Flash Flood Warning 13, NWS Honolulu, HI

August 22, 2015Honolulu County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Aug 22, 2015, 7:48 PM HST for Honolulu County, Hawaii. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 22, 2015, 7:48 PM HST (05:48 UTC)
Expired: Aug 22, 2015, 10:45 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), 90 km from the middle of the area, began a volume at 05:47 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.

The nearest sounding before it

Lihue, (PHLI), launched 00:00Z, 5.8 hours before the alert went out and 155 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: 1145 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 918 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 82 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

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

326 
WGHW50 PHFO 230548
FFWHFO
HIC003-230845-
/O.NEW.PHFO.FF.W.0013.150823T0548Z-150823T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HONOLULU HI
748 PM HST SAT AUG 22 2015

THE NATIONAL WEATHER SERVICE IN HONOLULU HAS ISSUED A

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

* UNTIL 1045 PM HST

* AT 742 PM HST...THE WAIHEE RIVER GAGE NEAR WAIAHOLE SHOWED A RAPID 
  RISE IN WATER LEVEL...EXCEEDING THE WARNING LEVEL...FROM THE HEAVY 
  RAIN NEAR KAHALUU. THE AREA OF HEAVY RAIN WAS NEARLY STATIONARY.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  PUNALUU...WAIAHOLE...WAIKANE...LAIE...KAHUKU AND HAUULA.

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 OAHU IN HONOLULU COUNTY.

THIS WARNING MAY NEED TO BE EXTENDED BEYOND 1045 PM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2165 15806 2174 15796 2127 15764 2139 15791

$$

2 follow-up statements

281 
WGHW70 PHFO 230711
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
911 PM HST SAT AUG 22 2015

HIC003-230845-
/O.CON.PHFO.FF.W.0013.000000T0000Z-150823T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HONOLULU HI-
911 PM HST SAT AUG 22 2015

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE ISLAND OF OAHU IN
HONOLULU COUNTY UNTIL 1045 PM HST...

AT 855 PM HST...RADAR CONTINUES TO INDICATE HEAVY RAIN ALONG THE 
KOOLAU FROM MAUNAWILI TO TURTLE BAY. RIVER GAGES AT WAIAHOLE AND 
WAIHEE STREAMS HAVE BRIEFLY REACHED THE WARNING LEVELS IN THE PAST 
HOUR BUT THE LEVELS ARE STARTING TO DROP NOW.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PUNALUU...
WAIAHOLE...WAIKANE...LAIE...KAHUKU AND HAUULA.

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 1045 PM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2165 15806 2174 15796 2127 15764 2139 15791

$$

658 
WGHW70 PHFO 230816
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
1016 PM HST SAT AUG 22 2015

HIC003-230825-
/O.CAN.PHFO.FF.W.0013.000000T0000Z-150823T0845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HONOLULU HI-
1016 PM HST SAT AUG 22 2015

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

WEATHER RADAR SHOWED THAT HEAVY RAINFALL HAS MOVED OFFSHORE. THUS THE
FLASH FLOOD WARNING IS CANCELLED.

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

A FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 6 PM HST MONDAY FOR ALL 
ISLANDS.

LAT...LON 2165 15806 2174 15796 2127 15764 2139 15791

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 22, 4:03 PM HST	Areal Flood Advisory	HFO	Hawaii	3 hr
Aug 22, 7:04 PM HST	Areal Flood Advisory	HFO	Honolulu	3 hr
Aug 22, 8:22 PM HST	Areal Flood Advisory	HFO	Kalawao	3 hr
Aug 22, 8:44 PM HST	Flash Flood Warning	HFO	Kalawao	3 hr
Aug 22, 8:48 PM HST	Areal Flood Advisory	HFO	Hawaii	3 hr
Aug 22, 9:23 PM HST	Areal Flood Advisory	HFO	Kauai	3 hr
Aug 22, 9:45 PM HST	Areal Flood Advisory	HFO	Kalawao	3 hr
Aug 22, 10:53 PM HST	Areal Flood Advisory	HFO	Kalawao	3 hr
Aug 22, 11:39 PM HST	Areal Flood Advisory	HFO	Hawaii	5 hr
Aug 23, 12:20 AM HST	Areal Flood Advisory	HFO	Kalawao	3 hr
Aug 23, 1:09 AM HST	Flash Flood Warning	HFO	Kalawao	3 hr
Aug 23, 6:46 AM HST	Areal Flood Advisory	HFO	Hawaii	3 hr
Aug 23, 11:20 AM HST	Areal Flood Advisory	HFO	Honolulu	6 hr
Aug 23, 1:02 PM HST	Areal Flood Advisory	HFO	Hawaii	3 hr
Aug 23, 1:49 PM HST	Special Marine Warning	HFO		86 min
Aug 23, 1:56 PM HST	Areal Flood Advisory	HFO	Kauai	9 hr

Nearby

Flash Flood Warnings in Hawaii, 2015 Every flash flood warning in 2015

Sources

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