Alert archive / Hawaii / Flash Flood Warnings in 2021
Flash Flood Warning 6, NWS Honolulu, HI
NWS Honolulu, HI issued this flash flood warning at Jan 25, 2021, 3:45 PM HST for Honolulu County, Hawaii. It was in force for 3 hr. 4 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
- Jan 25, 2021, 3:45 PM HST (01:45 UTC)
- Expired
- Jan 25, 2021, 6:45 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), 75 km from the middle of the area, began a volume at 01:49 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 |
|---|---|---|---|
| Jan 25, 3:54 PM HST | FLASH FLOOD | Manoa, HI | MEDIA REPORTED NEARLY 18,000 GALLON SEWAGE SPILL AT LOWRY STREET. |
| Jan 25, 5:00 PM HST | FLASH FLOOD | Honolulu, HI | H1 FREEWAY WEST BOUND LANES FLOODED WITH 1 TO 3 FT OF WATER. |
| Jan 25, 5:58 PM HST | FLASH FLOOD | Waipahu, HI | *** 1 INJ *** BOY TAKEN TO HOSPITAL WITH MINOR SCRAPES AFTER BEING SWEPT INTO RAGING CANAL IN WAIPAHU. |
| Jan 25, 5:58 PM HST | FLASH FLOOD | Waipahu, HI | *** 1 INJ *** TWO YOUNG BOYS WERE SWEPT INTO FLOODED CANAL IN WAIPAHU. ONE BOY TAKEN TO HOSPITAL WITH MINOR SCRAPES. |
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, 1.8 hours before the alert went out and 168 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
- 312 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 810 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 20 m²/s²
- 0-3 km storm-relative helicity
- 20 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
928
WGHW50 PHFO 260145
FFWHFO
HIC003-260445-
/O.NEW.PHFO.FF.W.0006.210126T0145Z-210126T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Honolulu HI
345 PM HST Mon Jan 25 2021
The National Weather Service in Honolulu has issued a
* Flash Flood Warning for...
The island of Oahu in Honolulu County
* Until 645 PM HST.
* At 345 PM HST, radar indicated a band of intense heavy rain over
southern Oahu, including urban Honolulu. The heaviest showers were
falling at a rate of 1 to 3 inches per hour over East Honolulu and
were spreading westward. 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, Aiea, Halawa, Pearl City, Salt Lake, Moanalua, Kalihi,
Ahuimanu, Waikele, Waiahole, Kahaluu, Waipahu, Iroquois Point,
Waikane, Mililani, Kunia, Kaneohe, Ewa Beach, Wheeler Field 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.
&&
This warning may need to be extended beyond 645 PM HST if flooding
persists.
LAT...LON 2149 15815 2159 15797 2156 15784 2147 15783
2143 15779 2147 15779 2148 15775 2143 15772
2141 15772 2134 15768 2131 15763 2125 15769
2125 15772 2127 15772 2124 15782 2129 15787
2129 15796 2131 15797 2129 15812 2134 15813
FLASH FLOOD...RADAR INDICATED
$$
WROE2 follow-up statements
903
WGHW70 PHFO 260316
FFSHFO
Flash Flood Statement
National Weather Service Honolulu HI
516 PM HST Mon Jan 25 2021
HIC003-260445-
/O.CON.PHFO.FF.W.0006.000000T0000Z-210126T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Honolulu HI-
516 PM HST Mon Jan 25 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM HST THIS
EVENING FOR THE ISLAND OF OAHU IN HONOLULU COUNTY...
At 516 PM HST, radar and rain gauges showed that heavy showers have
decreased in intensity but continue to fall over the southern half
of Oahu at rates of 1 to 2 inches per hour. Stream gauges in urban
Honolulu have decreased slightly, though water levels remain
elevated. Additional heavy rainfall is expected into early evening.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Radar indicated.
IMPACT...Flooding in drainages, streams, rivers, roads,
properties, and other low-lying areas. Public road
closures possible in some areas. Landslides are possible
in steep terrain.
Some locations that will experience flash flooding include...
Honolulu, Aiea, Halawa, Pearl City, Salt Lake, Moanalua, Kalihi,
Ahuimanu, Waikele, Waiahole, Kahaluu, Waipahu, Iroquois Point,
Waikane, Mililani, Kunia, Kaneohe, Ewa Beach, Wheeler Field and
Manoa.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Stay away from streams, rivers, drainage ditches, and culverts, even
if they are currently dry.
Do not cross fast flowing or rising water in your vehicle, or on
foot. Turn around, don't drown.
&&
This warning may need to be extended beyond 645 PM HST if flooding
persists.
LAT...LON 2149 15815 2159 15797 2156 15784 2147 15783
2143 15779 2147 15779 2148 15775 2143 15772
2141 15772 2134 15768 2131 15763 2125 15769
2125 15772 2127 15772 2124 15782 2129 15787
2129 15796 2131 15797 2129 15812 2134 15813
FLASH FLOOD...RADAR INDICATED
$$
WROE872
WGHW70 PHFO 260444
FFSHFO
Flash Flood Statement
National Weather Service Honolulu HI
644 PM HST Mon Jan 25 2021
HIC003-260454-
/O.EXP.PHFO.FF.W.0006.000000T0000Z-210126T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Honolulu HI-
644 PM HST Mon Jan 25 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 645 PM HST THIS EVENING FOR
THE ISLAND OF OAHU IN HONOLULU COUNTY...
Flood waters have receded, and there is no longer any significant
threat to life and property. Minor flooding of low lying and poor
drainage areas will continue however, and as a result the Flash
Flood Warning has been replaced by a Flood Advisory. Flooding is
Please continue to heed remaining road closures.
A Flash Flood Watch remains in effect for Oahu until 600 PM HST
Tuesday.
LAT...LON 2149 15815 2159 15797 2156 15784 2147 15783
2143 15779 2147 15779 2148 15775 2143 15772
2141 15772 2134 15768 2131 15763 2125 15769
2125 15772 2127 15772 2124 15782 2129 15787
2129 15796 2131 15797 2129 15812 2134 15813
$$
JELSEMAThe office that day
Everything else NWS Honolulu, HI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 25, 6:40 PM HST | Areal Flood Advisory | HFO | Honolulu | 2 hr |
| Jan 26, 12:39 AM HST | Areal Flood Advisory | HFO | Hawaii | 3 hr |
| Jan 26, 3:30 AM HST | Flash Flood Warning | HFO | Hawaii | 2 hr |
| Jan 26, 5:33 AM HST | Areal Flood Advisory | HFO | Hawaii | 3 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.