WEATHER UPDATE: Another kona storm may bring periods of moderate or heavy rain throughout the week, bringing renewed concerns for flooding across the islands
Key points
As of 9:00 AM HST on Monday, April 6:
Monday: Winds will begin to weaken and shift to a more easterly to southeasterly direction. Isolated rain showers are possible, particularly over windward and mauka areas.
Tuesday: Winds will shift to a more southerly direction, pulling abundant moisture up from the deep tropics. Isolated rain showers are possible, particularly over leeward and mauka areas. Isolated downpours are possible over areas of higher terrain.
Wednesday through Friday: An area of low pressure is likely to develop to the northwest of Kauaʻi on Wednesday. A series of upper-level disturbances will move across the islands over the next few days. Instability from these disturbances combined with the added moisture will result in periods of moderate to heavy rain, which could lead to flash flooding.
Upcoming weekend: Rainfall intensity may decrease over the weekend, but the threat of flash flooding could continue as the ground will remain saturated from the accumulated rain from earlier in the week.
Early next week: Long-range model guidance suggests that a second system could set up directly behind this storm, so impacts could continue into the upcoming week.
Forecast synopsis
As of 9:49 AM HST on Monday, April 6:
From the National Weather Service office in Honolulu:
Mostly dry and pleasant trade wind weather will continue today, with brief passing showers favoring windward and mauka areas. A significant pattern change is then expected by Tuesday as an upper disturbance and surface low pressure evolve northwest of the islands. This system is expected to draw deep tropical moisture northward over the state, leading to an extended period of southerly winds, increased chances for widespread rainfall, and renewed flooding concerns from from the middle of the week through the weekend.
Weather risk outlook
As of 8:00 AM HST on Monday, April 6:
| Island | MON | TUE | WED | THU | FRI |
|---|---|---|---|---|---|
| Kauaʻi | · | · | 1 | 2 | 2 |
| Oʻahu | · | · | 1 | 2 | 2 |
| Maui | · | · | 1 | 2 | 2 |
| Hawaiʻi | · | 1 | 1 | 2 | 2 |
Key: · - little to none; 1 - minor; 2 - moderate; 3 - major; 4 - extreme
Projected rainfall totals:
As of 9:00 AM HST on Monday, April 6:
Below are some preliminary projections for rainfall between now and 10:00 PM HST on Saturday, April 11.
Please note that it remains far too early to determine the exact timing and severity of any potential rainfall, and large differences in rainfall totals in the table below may be from large differences in timing and the location of the heaviest rain.
| City | NWS | ECMWF | GFS |
|---|---|---|---|
| Lihue | 6.0 | 5.6 | 6.7 |
| Honolulu | 5.6 | 4.3 | 7.3 |
| Wahiawa | 7.5 | 5.2 | 5.1 |
| Kaneohe | 7.2 | 5.7 | 5.9 |
| Kahului | 3.3 | 4.0 | 4.8 |
| Hana | 4.2 | 14.0 | 7.5 |
| Molokai | 5.7 | 3.5 | 5.6 |
| Lanai | 4.3 | 5.6 | 7.1 |
| Hilo | 3.4 | 13.0 | 4.4 |
| Kona | 3.3 | 3.5 | 3.3 |
More information
For more information on the impacts of this system as it develops, please check out these links:
National Weather Service
- NWS Honolulu homepage
- NWS Honolulu Area Forecast Discussion
- NWS Honolulu on Facebook
- NWS Honolulu on X
Hawaii Emergency Management Agency
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