Alert archive / Hawaii / Flash Flood Warnings in 2021
Flash Flood Warning 22, NWS Honolulu, HI
NWS Honolulu, HI issued this flash flood warning at Mar 10, 2021, 6:22 PM HST for Honolulu County, Hawaii. It was in force for 5 hr. 2 reports 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 10, 2021, 6:22 PM HST (04:22 UTC)
- Expired
- Mar 10, 2021, 10:52 PM HST
- In force
- 5 hr
- Issued by
- NWS Honolulu, HI
- Area
- Storm-based polygon
- Flood severity
- None
County Honolulu County, HI
The radar
The Molokai radar (PHMO), 75 km from the middle of the area, began a volume at 04:24 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 10, 7:50 PM HST | FLASH FLOOD | Waikiki, HI | CARS STALLED DUE TO FLOODING ON HOBRON LANE. |
| Mar 10, 7:53 PM HST | FLOOD | Honolulu, HI | CARS STALLED ON FLOODED HOBRON LANE IN WAIKIKI. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Lihue, (PHLI), launched 00:00Z, 4.4 hours before the alert went out and 169 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
- 858 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 769 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- 20 m²/s²
- 0-3 km storm-relative helicity
- 51 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
892
WGHW50 PHFO 110422
FFWHFO
HIC003-110730-
/O.NEW.PHFO.FF.W.0022.210311T0422Z-210311T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
622 PM HST Wed Mar 10 2021
The National Weather Service in Honolulu has issued a
* Flash Flood Warning for...
The island of Oahu in Honolulu County
* Until 930 PM HST.
* At 622 PM HST, radar indicated heavy rain over windward Oahu, and
along the south shore of Oahu east of the Honolulu Airport. Rain
was falling at a rate of around 2 inches per hour. Additionally,
Emergency Management reported a road at Kualoa Ranch has been
closed due to water over the roadway. Flash flooding is occurring
or expected to begin shortly.
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.
* Some locations that will experience flash flooding include...
Honolulu, Waiahole, Waikane, Kahaluu, Ahuimanu, Aiea, Pearl City,
Halawa, Kaaawa, Moanalua, Kaneohe, Salt Lake, Punaluu, Mililani,
Kalihi, Kaneohe Marine Base, Wahiawa, Maunawili, Hauula and Manoa.
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.
Excessive runoff from heavy rainfall will cause flooding of drainage
ditches and streams, streets, highways, properties, and other low
lying spots.
The heavy rains may cause rock and mudslides in steep terrain areas.
&&
This warning may need to be extended beyond 930 PM HST if flooding
persists.
LAT...LON 2163 15810 2173 15800 2172 15797 2155 15783
2147 15783 2143 15779 2147 15778 2147 15771
2141 15772 2134 15768 2132 15763 2126 15768
2125 15772 2127 15772 2125 15782 2129 15787
2129 15791 2129 15793 2131 15791 2131 15793
FLASH FLOOD...RADAR INDICATED
$$
JELSEMA3 follow-up statements
745
WGHW70 PHFO 110621
FFSHFO
Flash Flood Statement
National Weather Service Honolulu HI
821 PM HST Wed Mar 10 2021
HIC003-110730-
/O.CON.PHFO.FF.W.0022.000000T0000Z-210311T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Honolulu HI-
821 PM HST Wed Mar 10 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM HST THIS
EVENING FOR THE ISLAND OF OAHU IN HONOLULU COUNTY...
At 821 PM HST, radar indicated heavy rain over the south shore of
Oahu from the Honolulu Airport to Waikiki to Hawaii Kai. Rain was
falling at a rate of 1 to 2 inches per hour. Oahu Emergency
Management reported several cars stalled due to flooding in the
vicinity of Hobron Lane and Kaio'o Drive in Waikiki. Additionally,
Kamehameha Highway remains closed in both directions near Kualoa
Ranch due to water over the roadway. Additional heavy rain is
developing just south of Oahu and is expected to move onshore
shortly.
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.
Some locations that will experience flash flooding include...
Honolulu, Waiahole, Waikane, Kahaluu, Ahuimanu, Aiea, Pearl City,
Halawa, Kaaawa, Moanalua, Kaneohe, Salt Lake, Punaluu, Mililani,
Kalihi, Kaneohe Marine Base, Wahiawa, Maunawili, Hauula and Manoa.
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.
The heavy rains may cause rock and mudslides in steep terrain areas.
&&
This warning may need to be extended beyond 930 PM HST if flooding
persists.
LAT...LON 2163 15810 2173 15800 2172 15797 2155 15783
2147 15783 2143 15779 2147 15778 2147 15771
2141 15772 2134 15768 2132 15763 2126 15768
2125 15772 2127 15772 2125 15782 2129 15787
2129 15791 2129 15793 2131 15791 2131 15793
FLASH FLOOD...RADAR INDICATED
$$
JELSEMA685
WGHW50 PHFO 110710
FFWHFO
HIC003-111030-
/O.EXT.PHFO.FF.W.0022.000000T0000Z-210311T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
910 PM HST Wed Mar 10 2021
The National Weather Service in Honolulu has extended the
* Flash Flood Warning for...
The island of Oahu in Honolulu County
* Until 1230 AM HST.
* At 910 PM HST, radar indicated heavy rain over the south shore of
Oahu from the Honolulu Airport to Waikiki to Hawaii Kai. Rain was
falling at a rate of 1 to 2 inches per hour. Oahu Emergency
Management reported Kaio'o Drive remains closed between Hobron
Lane and Ala Moana Boulevard. Additionally, Kamehameha Highway
remains closed in both directions near Kualoa Ranch due to water
over the roadway. Additional heavy rain continues to develop south
of oahu and is expected to move onshore during the next few hours.
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.
* Some locations that will experience flash flooding include...
Honolulu, Waiahole, Waikane, Kahaluu, Ahuimanu, Aiea, Pearl City,
Halawa, Kaaawa, Moanalua, Kaneohe, Salt Lake, Punaluu, Mililani,
Kalihi, Kaneohe Marine Base, Wahiawa, Maunawili, Hauula and Manoa.
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.
The heavy rains may cause rock and mudslides in steep terrain areas.
&&
This warning may need to be extended beyond 1230 AM HST if flooding
persists.
LAT...LON 2163 15810 2173 15800 2172 15797 2155 15783
2147 15783 2143 15779 2147 15778 2147 15771
2141 15772 2134 15768 2132 15763 2126 15768
2125 15772 2127 15772 2125 15782 2129 15787
2129 15791 2129 15793 2131 15791 2131 15793
FLASH FLOOD...RADAR INDICATED
$$
JELSEMA074
WGHW70 PHFO 110852
FFSHFO
Flash Flood Statement
National Weather Service Honolulu HI
1052 PM HST Wed Mar 10 2021
HIC003-110902-
/O.CAN.PHFO.FF.W.0022.000000T0000Z-210311T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Honolulu HI-
1052 PM HST Wed Mar 10 2021
...FLASH FLOOD WARNING IS CANCELLED FOR THE ISLAND OF OAHU IN
HONOLULU COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
A Flash Flood Watch remains in effect until 600 PM HST Friday.
LAT...LON 2163 15810 2173 15800 2172 15797 2155 15783
2147 15783 2143 15779 2147 15778 2147 15771
2141 15772 2134 15768 2132 15763 2126 15768
2125 15772 2127 15772 2125 15782 2129 15787
2129 15791 2129 15793 2131 15791 2131 15793
$$
JELSEMAThe office that day
Everything else NWS Honolulu, HI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 10, 2:36 PM HST | Flash Flood Warning | HFO | Honolulu | 97 min |
| Mar 10, 3:00 PM HST | Special Marine Warning | HFO | 2 hr | |
| Mar 10, 3:11 PM HST | Small Craft Advisory | HFO | 13 hr | |
| Mar 10, 3:45 PM HST | Areal Flood Advisory | HFO | Kalawao | 3 hr |
| Mar 10, 4:13 PM HST | Areal Flood Advisory | HFO | Honolulu | 2 hr |
| Mar 10, 4:30 PM HST | Areal Flood Advisory | HFO | Hawaii | 2 hr |
| Mar 10, 4:36 PM HST | Special Weather Statement | HFO | Kauai | 24 min |
| Mar 10, 4:37 PM HST | Special Marine Warning | HFO | 113 min | |
| Mar 10, 4:58 PM HST | Areal Flood Advisory | HFO | Honolulu | 3 hr |
| Mar 10, 6:26 PM HST | Flash Flood Warning | HFO | Kauai | 3 hr |
| Mar 10, 6:34 PM HST | Special Marine Warning | HFO | 25 min | |
| Mar 10, 8:05 PM HST | Special Marine Warning | HFO | 46 min | |
| Mar 10, 8:12 PM HST | Special Marine Warning | HFO | 2 hr | |
| Mar 10, 9:18 PM HST | Special Marine Warning | HFO | 76 min | |
| Mar 10, 9:27 PM HST | Areal Flood Advisory | HFO | Honolulu | 86 min |
| Mar 10, 11:04 PM HST | Special Marine Warning | HFO | 116 min | |
| Mar 11, 2:23 AM HST | Areal Flood Advisory | HFO | Honolulu | 7 hr |
| Mar 11, 2:39 AM HST | Special Marine Warning | HFO | 2 hr | |
| Mar 11, 3:21 AM HST | Areal Flood Advisory | HFO | Kauai | 9 hr |
| Mar 11, 3:47 AM HST | Special Weather Statement | HFO | Kauai | 43 min |
| Mar 11, 1:39 PM HST | Areal Flood Advisory | HFO | Honolulu | 43 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.