Alert archive / Hawaii / Flash Flood Warnings in 2021

Flash Flood Warning 12, NWS Honolulu, HI

March 8, 2021Kalawao County, Hawaii

NWS Honolulu, HI issued this flash flood warning at Mar 8, 2021, 2:42 PM HST for Kalawao County, Hawaii. It was in force for 5 hr. 1 report 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: Mar 8, 2021, 2:42 PM HST (00:42 UTC)
Expired: Mar 8, 2021, 7:47 PM HST
In force: 5 hr
Issued by: NWS Honolulu, HI
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Kalawao County, HI

The radar

The Molokai radar (PHMO), 92 km from the middle of the area, began a volume at 00:43 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
Mar 8, 4:58 PM HST	FLASH FLOOD	2 N Kaupakulua, HI	MAUI COUNTY EMERGENCY MANAGEMENT AGENCY REPORTS THAT THE HANA HIGHWAY IS CLOSED FROM PEAHI RD NEAR HAIKU TO KEANAE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Hilo, (PITO), launched 00:00Z, 0.7 hours before the alert went out and 192 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: 375 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 667 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 56 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

474 
WGHW50 PHFO 090042
FFWHFO
HIC009-090345-
/O.NEW.PHFO.FF.W.0012.210309T0042Z-210309T0345Z/
/00000.0.DM.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
242 PM HST Mon Mar 8 2021

The National Weather Service in Honolulu has issued a

* Flash Flood Warning for...
  A Dam Failure below KAUPAKULUA DAM in...
  The island of Maui in Maui County

* Until 545 PM HST.

* At 242 PM HST, emergency management reported the imminent failure 
  of KAUPAKULUA DAM.

  HAZARD...Life threatening flash flooding from the imminent
           failure of KAUPAKULUA DAM.

  SOURCE...Emergency management.

  IMPACT...Life threatening flooding and significant property
           damage is expected in areas downstream from the
           KAUPAKULUA DAM including Hana Highway between Haiku
           and Pauwela

* The nearest downstream area from the dam is HAIKU AND PAUWELA.

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 545 PM HST if flooding 
persists.

LAT...LON 2093 15637 2095 15637 2096 15633 2096 15632
      2095 15624 2094 15625 2086 15628 2086 15633

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
DAM FAILURE...IMMINENT

$$

FOSTER

2 follow-up statements

370 
WGHW50 PHFO 090309
FFWHFO
HIC009-090645-
/O.EXT.PHFO.FF.W.0012.000000T0000Z-210309T0645Z/
/00000.0.DM.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
509 PM HST Mon Mar 8 2021

The National Weather Service in Honolulu has extended the

* Flash Flood Warning for...
  A Dam Failure below Kaupakalua Dam in...
  The island of Maui in Maui County

* Until 845 PM HST.

* At 509 PM HST, emergency management reported the imminent failure 
  of Kaupakalua Dam.

  HAZARD...Life threatening flash flooding from the imminent
           failure of Kaupakalua Dam.

  SOURCE...Emergency management.

  IMPACT...Life threatening flooding and significant property
           damage is expected in the Haiku and Pauwela areas
           downstream from the Kaupakalua Dam. Maui County
           officials have ordered evacuations in the affected
           area, and Hana Highway remains closed between Keanae
           and Peahi Road near Haiku.

* The nearest downstream area from the dam is Haiku and Pauwela.

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 845 PM HST if flooding 
persists.

LAT...LON 2093 15637 2095 15637 2096 15633 2096 15632
      2095 15624 2094 15625 2086 15628 2086 15633

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
DAM FAILURE...IMMINENT

$$

WROE

111 
WGHW70 PHFO 090547
FFSHFO

Flash Flood Statement
National Weather Service Honolulu HI
747 PM HST Mon Mar 8 2021

HIC009-090557-
/O.CAN.PHFO.FF.W.0012.000000T0000Z-210309T0645Z/
/00000.0.DM.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maui HI-
747 PM HST Mon Mar 8 2021

...FLASH FLOOD WARNING FOR THE FAILURE OF KAUPAKALUA DAM NEAR HAIKU 
IS CANCELLED FOR THE ISLAND OF MAUI IN MAUI COUNTY...

Maui Emergency Management Agency reported that the high water levels 
threatening the structural integrity of the Kaupakalua Dam have 
receded to a point such that an imminent failure is no longer 
expected.

Any additional heavy rainfall in the vicinity of the dam could lead 
to a short notice Flash Flood Warning for areas downstream of the 
Kaupakalua Dam, so residents are urged to closely follow the 
instructions provided by Maui Emergency Manangement officials.

A Flash Flood Watch remains in effect until 600 AM HST Wednesday.

LAT...LON 2093 15637 2095 15637 2096 15633 2096 15632
      2095 15624 2094 15625 2086 15628 2086 15633

$$

JELSEMA

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 8, 8:07 PM HST	High Surf Advisory	HFO	Honolulu, Kalawao	19 hr
Mar 8, 9:32 PM HST	Areal Flood Advisory	HFO	Kalawao	33 min
Mar 8, 10:05 PM HST	Flash Flood Warning	HFO	Kalawao	5 hr
Mar 8, 10:55 PM HST	Areal Flood Advisory	HFO	Kauai	6 hr
Mar 9, 5:02 AM HST	Areal Flood Advisory	HFO	Honolulu	3 hr
Mar 9, 8:05 AM HST	Areal Flood Advisory	HFO	Honolulu	28 min
Mar 9, 8:09 AM HST	Special Marine Warning	HFO		2 hr
Mar 9, 8:22 AM HST	Special Weather Statement	HFO	Honolulu	53 min
Mar 9, 8:33 AM HST	Flash Flood Warning	HFO	Honolulu	117 min
Mar 9, 9:15 AM HST	Special Weather Statement	HFO	Honolulu	30 min
Mar 9, 9:59 AM HST	Special Weather Statement	HFO	Honolulu	61 min
Mar 9, 10:03 AM HST	Special Marine Warning	HFO		54 min
Mar 9, 10:31 AM HST	Flash Flood Warning	HFO	Honolulu	6 hr
Mar 9, 10:55 AM HST	Areal Flood Advisory	HFO	Hawaii	11 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.