Alert archive / Hawaii / Flash Flood Warnings in 2021

Flash Flood Warning 41, NWS Honolulu, HI

December 5, 2021Hawaii County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Dec 5, 2021, 3:56 PM HST for Hawaii 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: Dec 5, 2021, 3:56 PM HST (01:56 UTC)
Expired: Dec 5, 2021, 8:59 PM HST
In force: 5 hr
Issued by: NWS Honolulu, HI
Area: Storm-based polygon
Flood severity: None

County Hawaii County, HI

The radar

The South Shore radar (PHWA), 41 km from the middle of the area, began a volume at 01:58 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 00:00Z, 1.9 hours before the alert went out and 51 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: 154 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 626 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 192 m²/s²
0-3 km storm-relative helicity: 307 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

As transmitted.

050 
WGHW50 PHFO 060156
FFWHFO
HIC001-060415-
/O.NEW.PHFO.FF.W.0041.211206T0156Z-211206T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
356 PM HST Sun Dec 5 2021

The National Weather Service in Honolulu has issued a

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

* Until 615 PM HST.

* At 356 PM HST, radar indicated rainfall intensifying over the Kau 
  and Puna Districts. Rain rates were 2 to 3 inches per hour near 
  Halemaumau and Wood Valley. The Belt Highway at Kawa Flats will be 
  at risk of closure. Rainfall is expected to continue into the 
  nighttime hours.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar.

  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...
  Hilo, Hawaiian Paradise Park, Volcano, Hawaii Volcanoes National 
  Park, Glenwood, Wood Valley, Mountain View, Pahala, Hawaiian 
  Acres, Pohakuloa Training Area, Punaluu Beach, Keaau, Orchidlands 
  Estates, Kawa Flats, Papaikou, Pahoa, Pepeekeo, Naalehu and Honomu.

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 615 PM HST if flooding 
persists.

This Flash Flood Warning replaces the previously issued Flood 
Advisory that was in effect for The island of Hawaii in Hawaii 
County.

LAT...LON 1907 15592 2006 15534 1999 15520 1988 15509
      1976 15508 1975 15500 1965 15497 1952 15479
      1945 15483 1934 15497 1925 15516 1925 15529
      1914 15545 1913 15550 1908 15554 1896 15559
      1891 15566 1902 15589

FLASH FLOOD...RADAR INDICATED

$$

KODAMA

3 follow-up statements

414 
WGHW70 PHFO 060316
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
516 PM HST Sun Dec 5 2021

HIC001-060415-
/O.CON.PHFO.FF.W.0041.000000T0000Z-211206T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hawaii HI-
516 PM HST Sun Dec 5 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM HST THIS 
EVENING FOR THE ISLAND OF HAWAII IN HAWAII COUNTY...

At 516 PM HST, radar indicated heavy rainfall continuing over the 
slopes of the Kau and Puna Districts. Radar estimated rain rates of 
2 to 4 inches per hour are occurring between Wood Valley and Volcano 
Village. Rainfall is expected to continue well into the nighttime 
hours.

HAZARD...Flash flooding caused by heavy rain.

SOURCE...Radar.

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...
  Hilo, Hawaiian Paradise Park, Volcano, Hawaii Volcanoes National 
  Park, Glenwood, Wood Valley, Mountain View, Pahala, Hawaiian 
  Acres, Pohakuloa Training Area, Punaluu Beach, Keaau, Orchidlands 
  Estates, Kawa Flats, Papaikou, Pahoa, Pepeekeo, Naalehu and Honomu.

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.

&&

LAT...LON 1907 15592 2006 15534 1999 15520 1988 15509
      1976 15508 1975 15500 1965 15497 1952 15479
      1945 15483 1934 15497 1925 15516 1925 15529
      1914 15545 1913 15550 1908 15554 1896 15559
      1891 15566 1902 15589

FLASH FLOOD...RADAR INDICATED

$$

KODAMA

819 
WGHW50 PHFO 060404
FFWHFO
HIC001-060715-
/O.EXT.PHFO.FF.W.0041.000000T0000Z-211206T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
604 PM HST Sun Dec 5 2021

The National Weather Service in Honolulu has extended the

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

* Until 915 PM HST.

* At 604 PM HST, radar indicated heavy rainfall continuing over the 
  slopes of the Kau and Puna Districts. Peak radar rainfall 
  estimates of 2 to 3 inches per hour have been occurring near Wood 
  Valley. Rainfall is expected to continue well into the nighttime 
  hours.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar.

  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...
  Hilo, Hawaiian Paradise Park, Volcano, Hawaii Volcanoes National 
  Park, Glenwood, Wood Valley, Mountain View, Pahala, Hawaiian 
  Acres, Pohakuloa Training Area, Punaluu Beach, Keaau, Orchidlands 
  Estates, Kawa Flats, Papaikou, Pahoa, Pepeekeo, Naalehu and Honomu.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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 915 PM HST if flooding 
persists.

LAT...LON 1907 15592 2006 15534 1999 15520 1988 15509
      1976 15508 1975 15500 1965 15497 1952 15479
      1945 15483 1934 15497 1925 15516 1925 15529
      1914 15545 1913 15550 1908 15554 1896 15559
      1891 15566 1902 15589

FLASH FLOOD...RADAR INDICATED

$$

KODAMA

136 
WGHW70 PHFO 060659
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
859 PM HST Sun Dec 5 2021

HIC001-060709-
/O.CAN.PHFO.FF.W.0041.000000T0000Z-211206T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hawaii HI-
859 PM HST Sun Dec 5 2021

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

The heavy rain has eased for the time being. Flooding is no longer 
expected to pose a threat in the short term, however a Flood Watch 
remains in effect, and heavy rain may redevelop later tonight.

LAT...LON 1907 15592 2006 15534 1999 15520 1988 15509
      1976 15508 1975 15500 1965 15497 1952 15479
      1945 15483 1934 15497 1925 15516 1925 15529
      1914 15545 1913 15550 1908 15554 1896 15559
      1891 15566 1902 15589

$$

Birchard

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 5, 2:30 PM HST	Areal Flood Advisory	HFO	Hawaii	86 min
Dec 5, 3:18 PM HST	Areal Flood Advisory	HFO	Kalawao	3 hr
Dec 5, 3:35 PM HST	Coastal Flood Statement	HFO	Hawaii, Honolulu, Kauai, Kalawao	42 hr
Dec 5, 4:27 PM HST	Flash Flood Warning	HFO	Kalawao	5 hr
Dec 5, 5:33 PM HST	Areal Flood Advisory	HFO	Kalawao	6 hr
Dec 5, 6:22 PM HST	Flash Flood Warning	HFO	Kalawao	3 hr
Dec 5, 8:02 PM HST	Gale Warning	HFO		7 hr
Dec 5, 8:02 PM HST	Small Craft Advisory	HFO		10 days
Dec 5, 9:16 PM HST	Flash Flood Warning Considerable damage threat	HFO	Kalawao	12 hr
Dec 5, 9:20 PM HST	Flash Flood Warning	HFO	Kalawao	11 hr
Dec 6, 12:37 AM HST	Areal Flood Advisory	HFO	Hawaii	11 hr
Dec 6, 3:24 AM HST	Winter Weather Advisory	HFO	Hawaii	12 hr
Dec 6, 3:26 AM HST	Gale Warning	HFO		12 hr
Dec 6, 3:37 AM HST	High Surf Advisory	HFO	Hawaii, Honolulu, Kauai, Kalawao	12 hr
Dec 6, 5:54 AM HST	Special Marine Warning	HFO		2 hr
Dec 6, 7:09 AM HST	Special Marine Warning	HFO		51 min
Dec 6, 7:39 AM HST	Special Weather Statement	HFO	Hawaii	51 min
Dec 6, 7:40 AM HST	Areal Flood Advisory	HFO	Honolulu	6 hr
Dec 6, 7:57 AM HST	Areal Flood Advisory	HFO	Kauai	3 hr
Dec 6, 11:30 AM HST	Flash Flood Warning	HFO	Hawaii	2 hr
Dec 6, 12:26 PM HST	Special Marine Warning	HFO		64 min
Dec 6, 1:12 PM HST	Special Weather Statement	HFO	Honolulu	63 min
Dec 6, 1:16 PM HST	Flash Flood Warning	HFO	Honolulu	15 hr
Dec 6, 1:20 PM HST	Special Marine Warning	HFO		55 min
Dec 6, 1:43 PM HST	Areal Flood Advisory	HFO	Hawaii	3 hr

Nearby

Flash Flood Warnings in Hawaii, 2021 Every 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.