Maui Surf

Wet Season Rainfall Outlook for Hawaii

October 18, 2010, 10:09 AM HST
* Updated October 18, 10:14 AM
Listen to this Article
2 minutes
Loading Audio... Article will play after ad...
Playing in :00
A
A
A

Summary of dry season
• Statewide: Drought worsened
o “Exceptional drought” (D4 category in U.S. Drought Monitor) spread to Kau
o “Moderate drought” (D1 category) went from 50% in May to 74% September
• Leeward Big Island “severe” (D2 category) to “exceptional” drought
o Worst conditions in South Kohala and south Kau
o Some improvement in Kona coffee belt from summer rainfall
• Drought broadly affecting agriculture
o Livestock, orchards, crops, ornamentals affected
• Windward rainfall frequency near normal but daily totals below normal
• Hilo and Kapapala Ranch remain on pace for driest year on record.
o Hilo: 37.05 inches through September, normal is over 90 inches.
 Record driest year: 1983, 68.09 inches
o Kapapala Ranch: 5.41 inches through September, normal is 42 inches.
 Record driest year: 1998, 13.42 inches

Outlook for wet season
• Climate Prediction Center (CPC): La Nina is the primary influence
o Drier than normal through November
o Wetter than normal January through April/May
o More uncertainty compared to last year’s forecast with El Nino
• Previous wet seasons with moderate/strong La Nina
o 1999, 2000, 2008 are most recent examples
o Higher than normal frequency of trades
o Occasional upper level lows produced heavy rainfall
o Wet conditions primarily affected windward areas
o Leeward areas remained dry during 1999 & 2000 events
• Drought recovery more likely on smaller islands (Kauai to Molokai) and over windward slopes of Big Island and Maui
• Possibility of drought to continue through the wet season, especially over leeward areas if conditions similar to 1999 and 2000.

Wet season preparedness
• Clean gutters and drainage ditches
• If you live in a flood-prone area, identify your evacuation routes ahead of time
• Plan for more rainy weather impacts
o Increased road travel times or possible detours due to flooding
o Outdoor activities may be postponed, canceled, or adjusted
• Increased potential for lightning strikes
o Be prepared for possible power outages
o Move indoors during a thunderstorm
• Do you have a NOAA Weather Radio?

On the Web:
NOAA National Weather Service Honolulu HI: http://www.weather.gov/hawaii/
Hawaii Dry Season (May – September) Maps
Kauai: http://www.prh.noaa.gov/hnl/hydro/pages/kauai_2010_kau.gif
Oahu: http://www.prh.noaa.gov/hnl/hydro/pages/oahu_2010_kau.gif
Molokai and Lanai: http://www.prh.noaa.gov/hnl/hydro/pages/molan_2010_kau.gif
Maui: http://www.prh.noaa.gov/hnl/hydro/pages/maui_2010_kau.gif
Big Island: http://www.prh.noaa.gov/hnl/hydro/pages/bigis_2010_kau.gif

Make the most of your Maui vacation with these top-rated activities: Maui Top 20: Maui Visitor & Tourism Information
E-Mail Newsletters Receive daily or weekly updates via e-mail. Subscribe Now
News Alerts Breaking news alerts on your mobile device. Get the App

Comments

This comments section is a public community forum for the purpose of free expression. Although Maui Now encourages respectful communication only, some content may be considered offensive. Please view at your own discretion. View Comments