Alert archive / Hawaii / Flash Flood Warnings in 2011

Flash Flood Warning 41, NWS Honolulu, HI

December 13, 2011Honolulu County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Dec 13, 2011, 2:26 AM 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: Dec 13, 2011, 2:26 AM HST (12:26 UTC)
Expired: Dec 13, 2011, 5:20 AM 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), 75 km from the middle of the area, began a volume at 12:25 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
Dec 13, 2:45 AM HST	FLASH FLOOD	Manoa, HI	WATER FROM MANOA STREAM JUMPED OUT OF BANK NEAR WOODLAWN ST. BRIDGE. PROPERTY INUNDATED BY NEARLY 1 FT OF WATER AND MUD.
Dec 13, 3:50 AM HST	FLASH FLOOD	Honolulu, HI	H1 WEST BOUND SCHOOL STREET OFF RAMP COMPLETELY CLOSED OFF DUE TO A MUDSLIDE.

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 12:00Z, 0.4 hours before the alert went out and 168 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: 1264 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 456 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 12 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.

855 
WGHW50 PHFO 131226
FFWHFO
HIC003-131530-
/O.NEW.PHFO.FF.W.0041.111213T1226Z-111213T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HONOLULU HI
226 AM HST TUE DEC 13 2011

THE NATIONAL WEATHER SERVICE IN HONOLULU HAS ISSUED A

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

* UNTIL 530 AM HST

* AT 216 AM HST...RADAR SHOWED HEAVY RAIN AND THUNDERSTORMS FROM 
  MILILANI TO KAHALA. THE AREA OF RAIN AND STORMS ARE MOVING 
  SOUTHWEST AT 10 TO 15 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SALT
  LAKE...WAIMANALO...PEARL CITY...MAUNAWILI...KANEOHE...KAILUA...
  KAHALUU...HALAWA AND AIEA.

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 530 AM HST IF FLASH
FLOODING PERSISTS.

LAT...LON 2149 15787 2138 15769 2122 15780 2142 15801

$$
LAU

1 follow-up statement

292 
WGHW70 PHFO 131520
FFSHFO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HONOLULU HI
520 AM HST TUE DEC 13 2011

HIC003-131527-
/O.CAN.PHFO.FF.W.0041.000000T0000Z-111213T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HONOLULU HI-
520 AM HST TUE DEC 13 2011

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

WEATHER RADAR SHOWS THE HEAVY SHOWERS AND THUNDERSTORMS HAVE ABATED.
ALSO...THE RIVER GAGES SHOWS THE STREAMS HAVE SUBSIDED. THUS THE 
FLASH FLOOD WARNING IS CANCELLED.

LAT...LON 2149 15787 2138 15769 2122 15780 2142 15801

$$
LAU

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 12, 10:33 PM HST	Areal Flood Advisory	HFO	Honolulu	3 hr
Dec 13, 1:22 AM HST	Areal Flood Advisory	HFO	Honolulu	3 hr
Dec 13, 1:40 AM HST	Areal Flood Advisory	HFO	Kalawao	3 hr
Dec 13, 3:05 AM HST	Flash Flood Watch	HFO	Hawaii, Honolulu, Kalawao	24 hr
Dec 13, 8:26 AM HST	Areal Flood Advisory	HFO	Kalawao	2 hr
Dec 13, 11:52 AM HST	Areal Flood Advisory	HFO	Kalawao	46 min

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.