Area Forecast Discussion
Issued by NWS Honolulu, HI
Issued by NWS Honolulu, HI
896 FXHW60 PHFO 131916 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 916 AM HST Sun Sep 13 2026 .SYNOPSIS... Drier trade winds will prevail early this week with light showers on the windward side of the islands. Low level convergence along a surface trough will bring a modest increase in clouds and showers late Monday into Tuesday. More rain is expected through the second half of the week as remnants of Tropical Storm Norbert pass through the region. && .SHORT TERM UPDATE... Skies were mostly sunny this morning except for windward Big Island and northeast Maui. Winds were averaging 5 to 15 mph with a few spots gusting to near 20 mph. These relatively light trade winds are expected to continue through the day with only isolated light showers forecast. No changes will be made to the forecast at this time. && .AVIATION... No major changes to the forecast this morning as drier trade wind weather prevails. Shower activity should remain limited today thanks to these winds, with the windward side of the islands having a 15-40% chance for showers while the rest of the areas remain dry. If anything, we`ll likely see cumulus clouds skirt by. In fact, satellite imagery this morning has shown cumulus clouds develop and generally migrate eastward or bank up along the windward side of islands. In terms of winds today, look for weak to moderate trades to continue. Winds may become light enough within more wind- protected leeward areas to initiate local topographically- driven breezes. There are currently no AIRMETs in effect. Will need to keep an eye on the clouds to see if we reach mountain obscuration criteria today. && .MARINE... Issued at 331 AM HST Sun Sep 13 2026 Moderate to locally fresh trades will continue through the week before gradually strengthening through the latter half of the week. Moisture associated with a weak trough moving in on the trade wind flow may bring a slight uptick in shower activity to the coastal waters Tuesday into Wednesday. While the current forecast has Tropical Storm Norbert dissipating before it nears the Hawaiian coastal waters from the east, remnant moisture from this system is expected to arrive potentially by Thursday, likely bringing more showers. Surf along south-facing shores will gradually decline through Monday as the small, medium-period energy slowly fades. A series of long-period swells are expected during the second half of the week. The first pulse will gradually fill in Tuesday into Wednesday out of the southwest, followed by larger south-southwest swells Friday into the weekend. Surf could get near advisory thresholds over the weekend, but at this time it looks like it would peak just below advisory thresholds. A small short-period northeast swell filled in overnight and will peak today and fade out on Monday. Surf along east-facing shores should see an increase during the second half of the week as the trades strengthen and the remnants of Norbert moves through the islands. Some small energy is expected along northern exposures today from the northeast swell, but otherwise flat to tiny surf along north facing shores is expected through the forecast period. && .FIRE WEATHER... Issued at 331 AM HST Sun Sep 13 2026 Fire weather risk will remain low the next several days due light to moderate winds and the effects of recent rainfall. Inversion heights are expected to remain elevated or weak through Monday. Moisture increases for the middle to latter part of the week with a bump in the trade winds as remnants from Tropical Storm Norbert potentially approach the area. && .HFO WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM UPDATE...Parker DISCUSSION/FIRE WEATHER...SS AVIATION...KR MARINE...Shigesato