590 FXHW60 PHFO 300133 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 333 PM HST Sat Jun 29 2019 .SYNOPSIS... A drying trend along with a return of a more typical trade wind pattern is expected through the rest of the weekend and early next week. The best rainfall chances will remain over Kauai County and its surrounding leeward waters tonight as the area of low pressure that brought all of the rain this week drifts westward and away from the state. Elsewhere, clouds and showers will favor windward areas through early next week. Trades will trend down Wednesday into the second half of the week, potentially giving way to a land and sea breeze regime. && .DISCUSSION... Satellite imagery and observations showed the area of low pressure that has been responsible for the wet and humid conditions this week drifting westward and away from the islands. Although a drying trend has begun over the eastern end of the state, plenty of moisture lingering over Kauai County and its surrounding leeward waters will keep the rain chances in place. Recent satellite-derived precipitable water (PW) imagery and upper air soundings reflected this and showed a sharp east to west gradient with values ranging from around 1.25 inches over the Big Island to around 2 inches over Kauai. A few heavy showers and even a thunderstorm managed to develop over leeward Kauai through the early afternoon period, but quickly dissipated thereafter. The nearest rain gage was Waimea Heights, where .35 inches was recorded during this three hour time frame. Elsewhere, mostly quiet conditions have prevailed today and will likely continue into the evening and overnight period tonight. The latest short-term guidance remains in good agreement through early next week and continues to advertise a drying trend from east to west and a more typical trade wind pattern. Cloud/shower coverage will transition back to windward and mountain locations. The exception will be over the far western end of the island chain tonight due to the aforementioned moisture and better instability. Rain chances have been increased slightly and a slight chance of thunderstorms has been included to the leeward Kauai waters this evening. Farther east, windward shower coverage may slightly increase over Maui and the Big Island later tonight through early Sunday morning as an area of moisture (1.4" PWs) approaches and moves in from the east within the trades. The extended guidance depicts the ridge weakening due to a front and upper trough passing to the north around Wednesday. If this scenario evolves, trades will weaken through the second half of the week, with land and sea breeze conditions returning. && .AVIATION... High pressure northeast of the state will keep moderate trade winds in place across the island chain through this weekend. Clouds and showers will favor windward and mauka areas, with a stray shower spilling over into leeward areas from time to time. Some brief MVFR cigs/vis are possible in passing showers, but VFR conditions will prevail over the next 24 hours. No AIRMETs are expected through Sunday. && .MARINE... Moderate to locally breezy trade winds are expected to continue across eastern and central portions of the forecast area through the rest of the weekend. Thus, a Small Craft Advisory (SCA) remains in effect for the Alenuihaha Channel and waters south of the Big Island. A rising south-southwest swell will lead to advisory-level surf along south facing shores of all islands tonight through Monday afternoon. Additional swells arriving from the southern hemisphere will continue to maintain small to moderate surf along south facing shores from Monday night into the middle of next week. Elsewhere, expect a modest increase in short-period choppy surf along east facing shores this weekend due to the return of the easterly trade winds. && .HFO WATCHES/WARNINGS/ADVISORIES... High Surf Advisory until 6 PM HST Monday for all south facing shores. Small Craft Advisory until 6 PM HST Sunday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters. && $$ DISCUSSION...Gibbs AVIATION...Stall MARINE...Powell