Hawaii, 2003

Heavy Rain in Hawaii, April 20, 2003

April 20, 2003 · NWS HFO · 1 event in 1 county or zone

Heavy showers and thunderstorms caused ponding of roadways, and small stream and drainage ditch flooding in windward and southeastern areas of the Big Island of Hawaii, from North Kohala to Kau. No serious property damage or injuries were reported, however.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS HFO wrote it up.

Heavy showers and thunderstorms caused ponding of roadways, and small stream and drainage ditch flooding in windward and southeastern areas of the Big Island of Hawaii, from North Kohala to Kau. No serious property damage or injuries were reported, however.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Honolulu, HI wrote its last area forecast discussion before the first event at Apr 19, 8:30 PM HST, 7 hours 25 minutes earlier.

Area forecast discussion, Apr 19, 8:30 PM HST, 7 hours 25 minutes before
HAWAIIAN ISLANDS SYNOPTIC DISCUSSION AND GUIDANCE
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SAT APR 19 2003

SUMMARY...HIGH PRESSURE NORTH OF THE STATE WILL MAINTAIN TRADE WINDS
ACROSS THE STATE THROUGH NEXT WEEK. LOW PRESSURE DYNAMICS ALOFT WILL
OCCASIONALLY ENHANCE THE TRADE WIND SHOWERS... ESPECIALLY DURING THE
SECOND HALF OF THE COMING WEEK.

DISCUSSION...WHILE A STRONG SURFACE HIGH PRESSURE SYSTEM NORTH OF
THE STATE WILL MAINTAIN FRESH TO STRONG TRADE WINDS THROUGH THE
WEEK...LOW PRESSURE TROUGHING AT MID LEVELS OF THE UPPER ATMOSPHERE
WILL TEND TO ENHANCE OUR TRADE WIND SHOWERS AT TIMES. THIS MID-LEVEL
TROUGH IS FORECAST TO CUT-OFF INTO A CLOSED LOW LATE WEDNESDAY OVER
THE ISLANDS...AND THIS WILL DESTABILIZE THE ATMOSPHERE OVER THE
STATE...AND SLIGHTLY REDUCE OUR TRADE WIND SPEEDS. WITH THIS
DESTABILIZATION...TRADE WIND MOISTURE COMING INTO THE STATE WILL
BUILD INTO HEAVIER SHOWERS AND POSSIBLY INTO THUNDERSTORMS...MAINLY
OVER WINDWARD AND MAUKA SECTIONS OF THE ISLANDS...BUT ALSO LIKELY
BLOWING OVER INTO LEEWARD SECTIONS AT TIMES AS WELL. THE MID LEVEL
LOW MAY HAVE A DELETERIOUS EFFECT ON OUR WEATHER RIGHT INTO NEXT
WEEKEND. FARRELL

.HFO...WATCHES......NONE
.      WARNINGS.....NONE
.      ADVISORIES...SMALL CRAFT ALL WATERS
.                   HIGH SURF SOUTH SHORES

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 heavy rain. Local standard time, as filed.

Heavy Rain, Hawaii

When
April 20, 3:55 AM HST to 6:45 AM HST
Where
Hawaii County, Hawi
Reported by
OFFICIAL NWS OBS.
Coordinates
19.602, -155.523 (the zone’s center; the record gives no point)

What these are

Heavy Rain
Rainfall totals unusual for the place and season that did not produce a flood.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Hawaii in 2003Every state in 2003This day in weather historyWarnings in Hawaii, April 2003

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5327486.