Alert archive / Hawaii / Flash Flood Warnings in 2021
Flash Flood Warning 29, NWS Honolulu, HI
NWS Honolulu, HI issued this flash flood warning at Mar 12, 2021, 4:08 PM HST for Honolulu County, Hawaii. It was in force for 3 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 12, 2021, 4:08 PM HST (02:08 UTC)
- Expired
- Mar 12, 2021, 7:15 PM 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), 84 km from the middle of the area, began a volume at 02:11 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
Lihue, (PHLI), launched 00:00Z, 2.1 hours before the alert went out and 159 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.
- Mixed-layer CAPE
- 156 J/kg
- Mixed-layer CIN
- -16 J/kg
- Mixed-layer LCL
- 694 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- -26 m²/s²
- 0-3 km storm-relative helicity
- -12 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
627
WGHW50 PHFO 130208
FFWHFO
HIC003-130515-
/O.NEW.PHFO.FF.W.0029.210313T0208Z-210313T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
408 PM HST Fri Mar 12 2021
The National Weather Service in Honolulu has issued a
* Flash Flood Warning for...
The island of Oahu in Honolulu County
* Until 715 PM HST.
* At 408 PM HST, radar showed that a band of heavy rainfall will
reach Oahu shortly from the west. As the band moves eastward
across the island, heavy rainfall will occur over already
saturated ground. This will produce rapid flooding and heavy
runoff. The band will take several hours to move east of the
island.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Radar indicated.
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.
* This warning includes the entire island of Oahu.
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.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Excessive runoff from heavy rainfall will cause flooding of drainage
ditches and streams, streets, highways, properties, and other low
lying spots.
&&
This warning may need to be extended beyond 715 PM HST if flooding
persists.
LAT...LON 2158 15830 2160 15813 2173 15797 2155 15783
2147 15783 2143 15779 2147 15778 2147 15771
2141 15772 2131 15763 2125 15769 2125 15772
2127 15772 2124 15782 2129 15787 2131 15797
2129 15812 2136 15815 2148 15825 2153 15825
FLASH FLOOD...RADAR INDICATED
$$
KODAMA2 follow-up statements
745
WGHW70 PHFO 130337
FFSHFO
Flash Flood Statement
National Weather Service Honolulu HI
537 PM HST Fri Mar 12 2021
HIC003-130515-
/O.CON.PHFO.FF.W.0029.000000T0000Z-210313T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Honolulu HI-
537 PM HST Fri Mar 12 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM HST THIS
EVENING FOR THE ISLAND OF OAHU IN HONOLULU COUNTY...
At 537 PM HST, radar showed a band of heavy rainfall moving eastward
across Oahu. The highest rain rates were 1 to 2 inches over the
Waianae Range and near Waimanalo. The rain band will take several
hours to move completely east of the island.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Radar indicated.
IMPACT...Flooding in drainages, streams, rivers, roads,
properties, and other low-lying areas. Public road
closures possible in some areas. Landslides are possible
in steep terrain.
This warning includes the entire island of Oahu.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Stay away from streams, rivers, drainage ditches, and culverts, even
if they are currently dry.
Do not cross fast flowing or rising water in your vehicle, or on
foot. Turn around, don't drown.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Excessive runoff from heavy rainfall will cause flooding of drainage
ditches and streams, streets, highways, properties, and other low
lying spots.
&&
This warning may need to be extended beyond 715 PM HST if flooding
persists.
LAT...LON 2158 15830 2160 15813 2173 15797 2155 15783
2147 15783 2143 15779 2147 15778 2147 15771
2141 15772 2131 15763 2125 15769 2125 15772
2127 15772 2124 15782 2129 15787 2131 15797
2129 15812 2136 15815 2148 15825 2153 15825
FLASH FLOOD...RADAR INDICATED
$$
KODAMA365
WGHW70 PHFO 130512
FFSHFO
Flash Flood Statement
National Weather Service Honolulu HI
712 PM HST Fri Mar 12 2021
HIC003-130522-
/O.EXP.PHFO.FF.W.0029.000000T0000Z-210313T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Honolulu HI-
712 PM HST Fri Mar 12 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 715 PM HST THIS EVENING FOR
THE ISLAND OF OAHU IN HONOLULU COUNTY...
The heavy rain has ended. Some additional showers are possible
though the night, but flooding is no longer expected to pose a
threat. Please continue to exercise caution with wet roadways.
A Flash Flood Watch remains in effect until 600 PM HST Saturday.
LAT...LON 2158 15830 2160 15813 2173 15797 2155 15783
2147 15783 2143 15779 2147 15778 2147 15771
2141 15772 2131 15763 2125 15769 2125 15772
2127 15772 2124 15782 2129 15787 2131 15797
2129 15812 2136 15815 2148 15825 2153 15825
$$
TSThe office that day
Everything else NWS Honolulu, HI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 12, 3:12 PM HST | Winter Weather Advisory | HFO | Hawaii | 48 hr |
| Mar 12, 3:13 PM HST | Areal Flood Advisory | HFO | Kalawao | 3 hr |
| Mar 12, 4:16 PM HST | High Surf Advisory | HFO | Honolulu, Kauai, Kalawao | 3 days |
| Mar 12, 5:46 PM HST | Areal Flood Advisory | HFO | Kalawao | 3 hr |
| Mar 12, 8:36 PM HST | Flash Flood Warning | HFO | Kalawao | 18 hr |
| Mar 12, 10:59 PM HST | Areal Flood Advisory | HFO | Kalawao | 3 hr |
| Mar 12, 11:01 PM HST | Areal Flood Advisory | HFO | Kalawao | 6 hr |
| Mar 13, 3:23 AM HST | Areal Flood Advisory | HFO | Kalawao | 119 min |
| Mar 13, 3:27 AM HST | Wind Advisory | HFO | Kauai | 12 hr |
| Mar 13, 4:05 AM HST | Areal Flood Advisory | HFO | Kauai | 2 hr |
| Mar 13, 4:43 AM HST | Areal Flood Advisory | HFO | Hawaii | 6 hr |
| Mar 13, 5:22 AM HST | Flash Flood Warning | HFO | Kalawao | 2 hr |
| Mar 13, 5:38 AM HST | Special Marine Warning | HFO | 112 min | |
| Mar 13, 6:03 AM HST | Special Weather Statement | HFO | Hawaii | 87 min |
| Mar 13, 6:22 AM HST | Flash Flood Warning | HFO | Kauai | 2 hr |
| Mar 13, 7:28 AM HST | Special Marine Warning | HFO | 2 hr | |
| Mar 13, 9:19 AM HST | Special Marine Warning | HFO | 116 min | |
| Mar 13, 9:24 AM HST | Special Marine Warning | HFO | 111 min | |
| Mar 13, 10:31 AM HST | Areal Flood Advisory | HFO | Hawaii | 7 hr |
| Mar 13, 11:07 AM HST | Special Marine Warning | HFO | 113 min | |
| Mar 13, 11:09 AM HST | Special Marine Warning | HFO | 2 hr | |
| Mar 13, 11:19 AM HST | Special Marine Warning | HFO | 116 min | |
| Mar 13, 12:38 PM HST | Areal Flood Advisory | HFO | Kauai | 15 hr |
| Mar 13, 12:47 PM HST | Special Marine Warning | HFO | 118 min | |
| Mar 13, 12:47 PM HST | Special Marine Warning | HFO | 108 min |
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.