Skip Navigation Links 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center



Follow the Weather Prediction Center on Facebook Follow the Weather Prediction Center on Twitter
NCEP Quarterly Newsletter
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/

Satellite and Radar Imagery
  GOES-East Satellite
  GOES-West Satellite
  National Radar
Product Archive
WPC Verification
   Medium Range
   Model Diagnostics
   Event Reviews
   Winter Weather
International Desks
Development and Training
WPC Overview
   About the WPC
   WPC History
   Other Sites
Meteorological Calculators
Contact Us
   About Our Site is the U.S. Government's official web portal to all federal, state, and local government web resources and services.
Hawaii Extended Forecast Discussion
(Caution: Version displayed is not the latest version. - Issued 1222Z Feb 20, 2018)
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
Abbreviations and acronyms used in this product

Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
722 AM EST Tue Feb 20 2018

Valid 00Z Wed Feb 21 2018 - 00Z Wed Feb 28 2018

Upper low to the north of the region will continue to lift
northward and weaken, allowing drier air to remain over Hawai'i.
Precipitable water values will generally be under 1.25 inches
through Wednesday. By Thursday, another upper low is forecast to
form to the northwest of the area (around 30N/170W or over the
Paphanaumokuakea Marine National Monument) with a downstream
narrow ridge along 150W. This will allow deep tropical moisture to
surge northward across the state with locally moderate to heavy
rain and embedded thunderstorms. Precipitable water values are
forecast to rise to between about 1 1/3 to 1 3/4 inches through
the period (next Tuesday) which is well above average for late
February. Ensembles indicate a reloading of the upper low near or
just west of the same location next week which may pull the
precipitable water axis westward next week, perhaps west of
Kauai/Ni'ihau. Latest 06Z GFS and 00Z ECMWF generally fall in line
within the ensemble spread, and a blend of these solutions should
suffice, though their QPF differences are much larger than their
500mb or surface patterns.