Alert archive / Hawaii / Flash Flood Warnings in 2018

Flash Flood Warning 21, NWS Honolulu, HI

March 15, 2018Kalawao County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Mar 15, 2018, 2:36 AM HST for Kalawao County, Hawaii. It was in force for 5 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
Mar 15, 2018, 2:36 AM HST (12:36 UTC)
Expired
Mar 15, 2018, 7:44 AM HST
In force
5 hr
Issued by
NWS Honolulu, HI
Area
Storm-based polygon
Flood severity
None

County Kalawao County, HI

The radar

The Kamuela/Kohala Apt radar (PHKM), 75 km from the middle of the area, began a volume at 12:37 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

Hilo, (PITO), launched 12:00Z, 0.6 hours before the alert went out and 160 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, Hilo, at 12:00Z on 2018-03-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 466 joules per kilogram.LCLLFCEL10008507005003002001001 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, Hilo, at 12:00Z on 2018-03-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 square meters per square second.1939Sfc1 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
466 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
512 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-23 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

104 
WGHW50 PHFO 151236
FFWHFO
HIC009-151530-
/O.NEW.PHFO.FF.W.0021.180315T1236Z-180315T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
236 AM HST THU MAR 15 2018

The National Weather Service in Honolulu has issued a

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

* Until 530 AM HST

* At 232 AM HST, radar indicated heavy rains have eased off, but is 
  still falling at a rate of around an inch an hour. Ohea Gulch 
  Stream has fallen to just below the critical flood stage value but 
  remains swollen.

* Locations in the warning include but are not limited to...
  Kaupo, Kipahulu, Nahiku and Hana. 

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 530 AM HST if heavy rain
persists.

LAT...LON 2068 15601 2069 15603 2065 15605 2062 15616
      2063 15622 2087 15617 2085 15613 2082 15611
      2083 15609 2078 15599 2073 15599

$$
Lau
2 follow-up statements
706 
WGHW50 PHFO 151510
FFWHFO
HIC009-151800-
/O.EXT.PHFO.FF.W.0021.000000T0000Z-180315T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
510 AM HST THU MAR 15 2018

The National Weather Service in Honolulu has extended the

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

* Until 800 AM HST

* After some 13 hours straight of continuous rain over the east end 
  of Maui, there are signs that this event is coming to an end. Hana 
  Airport has recorded 6.29 inches in a 24 hour period ending at 430 
  am HST, of which 4.29 inches fell in the past 12 hours. Oheo Gulch 
  has started to trend lower but remains swollen. Due to the 
  extended length of the rains, it will take a few hours for the 
  water to recede. Therefore the flash flood warning is extended for 
  another 3 hours. Any more flare ups will prolong the warning.

* Locations in the warning include but are not limited to...
  Kaupo, Kipahulu, Nahiku and Hana. 

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 800 AM HST if heavy rain
persists.

LAT...LON 2068 15601 2069 15603 2065 15605 2062 15616
      2063 15622 2087 15617 2085 15613 2082 15611
      2083 15609 2078 15599 2073 15599

$$
Lau
642 
WGHW70 PHFO 151744
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
744 AM HST THU MAR 15 2018

HIC009-151753-
/O.CAN.PHFO.FF.W.0021.000000T0000Z-180315T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maui HI-
744 AM HST THU MAR 15 2018

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

The heavy rain has ended.

LAT...LON 2068 15601 2069 15603 2065 15605 2062 15616
      2063 15622 2087 15617 2085 15613 2082 15611
      2083 15609 2078 15599 2073 15599

$$
Donaldson

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 14, 2:42 PM HSTAreal Flood AdvisoryHFOKalawao3 hr
Mar 14, 3:10 PM HSTFlash Flood WarningHFOKalawao9 hr
Mar 14, 4:55 PM HSTFlash Flood WatchHFOKauai20 hr
Mar 14, 6:26 PM HSTSpecial Marine WarningHFO109 min
Mar 14, 7:02 PM HSTFlash Flood WarningHFOKauai5 hr
Mar 14, 7:31 PM HSTSpecial Weather StatementHFOKauai44 min
Mar 14, 11:45 PM HSTFlash Flood WarningHFOKalawao3 hr
Mar 15, 4:09 AM HSTAreal Flood AdvisoryHFOKauai6 hr
Mar 15, 7:19 AM HSTFlash Flood WarningHFOKauai6 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.