Alert archive / Hawaii / Flash Flood Warnings in 2021

Flash Flood Warning 5, NWS Honolulu, HI

January 25, 2021Hawaii County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Jan 25, 2021, 10:47 AM HST for Hawaii County, Hawaii. It was in force for 6 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
Jan 25, 2021, 10:47 AM HST (20:47 UTC)
Expired
Jan 25, 2021, 4:24 PM HST
In force
6 hr
Issued by
NWS Honolulu, HI
Area
Storm-based polygon
Flood severity
None

County Hawaii County, HI

The radar

The South Shore radar (PHWA), 10 km from the middle of the area, began a volume at 20:51 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, 8.8 hours before the alert went out and 82 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 2021-01-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 118 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 2021-01-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 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
118 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
615 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
-38 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

343 
WGHW50 PHFO 252047
FFWHFO
HIC001-252345-
/O.NEW.PHFO.FF.W.0005.210125T2047Z-210125T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
1047 AM HST Mon Jan 25 2021

The National Weather Service in Honolulu has issued a

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

* Until 145 PM HST.

* At 1047 AM HST, radar and automated rain gauges indicated heavy 
  rain falling at a rate of 1 to 2 inches per hour over the Kau and 
  Puna Districts. Law enforcement has reported that flooding has 
  closed Highway 11 in the Kawa Flats area between mile markers 58 
  and 62.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar and automated gauges.

  IMPACT...Flooding in drainages, streams, rivers, roads,
           properties, and other low-lying areas. Public road
           closures possible in some areas. Landslides are
           possible in steep terrain.

* Some locations that will experience flash flooding include...
  Pahala, Wood Valley, Punaluu Beach, Kawa Flats, Naalehu, Hawaii 
  Volcanoes National Park, Hawaiian Ocean View, Volcano, Waiohinu, 
  Discovery Harbour and Hawaii Volcanoes Park Kahuku Unit.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Stay away from streams, rivers, drainage ditches, and culverts, even 
if they are currently dry.

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 145 PM HST if flooding 
persists.

LAT...LON 1928 15509 1925 15516 1925 15529 1914 15544
      1913 15550 1907 15554 1896 15559 1889 15568
      1896 15574 1904 15590 1905 15591 1925 15569
      1952 15526

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

WROE
4 follow-up statements
493 
WGHW70 PHFO 252229
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
1229 PM HST Mon Jan 25 2021

HIC001-252345-
/O.CON.PHFO.FF.W.0005.000000T0000Z-210125T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hawaii HI-
1229 PM HST Mon Jan 25 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 145 PM HST THIS 
AFTERNOON FOR THE ISLAND OF HAWAII IN HAWAII COUNTY...

At 1229 PM HST, radar and automated rain gauges continued to show 
persistent heavy rain falling at rates of 1 to 2 inches per hour 
over the Kau and Puna Districts. Law enforcement had earlier 
reported flooding on Highway 11 in the Kawa Flats area between mile 
markers 58 and 62, and a stream gage near Pahala remains elevated.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Radar and automated gauges.

IMPACT...Flooding in drainages, streams, rivers, roads,
         properties, and other low-lying areas. Public road
         closures possible in some areas. Landslides are possible
         in steep terrain.

Some locations that will experience flash flooding include...
  Pahala, Wood Valley, Punaluu Beach, Kawa Flats, Naalehu, Hawaii 
  Volcanoes National Park, Hawaiian Ocean View, Volcano, Waiohinu, 
  Discovery Harbour and Hawaii Volcanoes Park Kahuku Unit.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Stay away from streams, rivers, drainage ditches, and culverts, even 
if they are currently dry.

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 145 PM HST if flooding 
persists.

LAT...LON 1928 15509 1925 15516 1925 15529 1914 15544
      1913 15550 1907 15554 1896 15559 1889 15568
      1896 15574 1904 15590 1905 15591 1925 15569
      1952 15526

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

WROE
993 
WGHW50 PHFO 252333
FFWHFO
HIC001-260245-
/O.EXT.PHFO.FF.W.0005.000000T0000Z-210126T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
133 PM HST Mon Jan 25 2021

The National Weather Service in Honolulu has extended the

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

* Until 445 PM HST.

* At 133 PM HST, radar and automated rain gauges continued to show 
  heavy rain falling at rates of 1 to 2 inches per hour over the Kau 
  and Puna Districts. Emergency management reported that Highway 11 
  remains closed due to flooding in the Kawa Flats area near mile 
  marker 57.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar and automated gauges.

  IMPACT...Flooding in drainages, streams, rivers, roads,
           properties, and other low-lying areas. Public road
           closures possible in some areas. Landslides are
           possible in steep terrain.

* Some locations that will experience flash flooding include...
  Pahala, Wood Valley, Punaluu Beach, Kawa Flats, Naalehu, Hawaii 
  Volcanoes National Park, Hawaiian Ocean View, Volcano, Waiohinu, 
  Discovery Harbour and Hawaii Volcanoes Park Kahuku Unit.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Stay away from streams, rivers, drainage ditches, and culverts, even 
if they are currently dry.

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 445 PM HST if flooding 
persists.

LAT...LON 1928 15509 1925 15516 1925 15529 1914 15544
      1913 15550 1907 15554 1896 15559 1889 15568
      1896 15574 1904 15590 1905 15591 1925 15569
      1952 15526

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

WROE
690 
WGHW70 PHFO 260136
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
336 PM HST Mon Jan 25 2021

HIC001-260245-
/O.CON.PHFO.FF.W.0005.000000T0000Z-210126T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hawaii HI-
336 PM HST Mon Jan 25 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM HST THIS 
AFTERNOON FOR THE ISLAND OF HAWAII IN HAWAII COUNTY...

At 336 PM HST, radar and automated rain gauges show that rainfall is 
diminishing over the Kau and Puna Districts. However, emergency 
management reported that Highway 11 remains closed due to flooding 
in the Kawa Flats area near mile marker 57.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Radar and automated gauges.

IMPACT...Flooding in drainages, streams, rivers, roads,
         properties, and other low-lying areas. Public road
         closures possible in some areas. Landslides are possible
         in steep terrain.

Some locations that will experience flash flooding include...
  Pahala, Wood Valley, Punaluu Beach, Kawa Flats, Naalehu, Hawaii 
  Volcanoes National Park, Hawaiian Ocean View, Volcano, Waiohinu, 
  Discovery Harbour and Hawaii Volcanoes Park Kahuku Unit.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Stay away from streams, rivers, drainage ditches, and culverts, even 
if they are currently dry.

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 445 PM HST if flooding 
persists.

LAT...LON 1928 15509 1925 15516 1925 15529 1914 15544
      1913 15550 1907 15554 1896 15559 1889 15568
      1896 15574 1904 15590 1905 15591 1925 15569
      1952 15526

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

WROE
135 
WGHW70 PHFO 260224
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
424 PM HST Mon Jan 25 2021

HIC001-260234-
/O.CAN.PHFO.FF.W.0005.000000T0000Z-210126T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hawaii HI-
424 PM HST Mon Jan 25 2021

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

Heavy rain has decreased significantly over windward and southeast 
Big Island. The Flash Flood Warning is cancelled, but please 
continue to heed remaining road closures along Highway 11 in Kau 
near Kawa Flats.

A Flash Flood Watch remains in effect until 600 PM HST Tuesday.

LAT...LON 1928 15509 1925 15516 1925 15529 1914 15544
      1913 15550 1907 15554 1896 15559 1889 15568
      1896 15574 1904 15590 1905 15591 1925 15569
      1952 15526

$$

WROE

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 24, 3:23 PM HSTWinter Weather AdvisoryHFOHawaii12 hr
Jan 25, 2:09 AM HSTAreal Flood AdvisoryHFOHawaii3 hr
Jan 25, 3:06 AM HSTWinter Storm WarningHFOHawaii36 hr
Jan 25, 4:24 AM HSTAreal Flood AdvisoryHFOHawaii3 hr
Jan 25, 7:26 AM HSTAreal Flood AdvisoryHFOHawaii6 hr
Jan 25, 1:48 PM HSTAreal Flood AdvisoryHFOHonolulu3 hr

Nearby

Flash Flood Warnings in Hawaii, 2021Every flash flood warning in 2021

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.