999 FXCA62 TJSJ 062100 AFDSJU Area Forecast Discussion National Weather Service San Juan PR 500 PM AST Mon Sep 6 2021 .SYNOPSIS...A seasonable weather pattern will prevail across the local area through most of the work week, with afternoon convection expected each day across portions of interior and western Puerto Rico. Swells from Hurricane Larry will result in deteriorated marine and coastal conditions through the middle of the week. && .SHORT TERM...Tonight through Tuesday... A seasonable weather pattern will continue to prevail during the next several days with the moisture content to fluctuate to near to slightly below normal levels. Hurricane Larry, currently located more than 800 miles east-northeast of the local area, will continue to induce an east-northeast flow through Tuesday. Patches of low-level moisture will be moving into the area, triggering some passing showers overnight tonight into Tuesday morning across portions of northeast Puerto Rico and the northern USVI followed by afternoon convection across the interior and southwestern portions of Puerto Rico. On Wednesday, as Larry moves to a position well north-northeast of the area, the low-level flow will become east-southeast. The steering flow will also diminish as well as Larry will also weaken the pressure gradient. With the steering flow switching from the east-southeast, the afternoon convection will be concentrated across the northwestern quadrant of Puerto Rico. High temperatures will continue to range in the upper 80s to lower 90s. However, with the high levels of humidity prevailing, heat indices will continue to push into the 100s across mainly of the lower elevation areas. .LONG TERM...Thursday through Monday... .PREV DISCUSSION... /issued 500 AM AST Mon Sep 6 2021/ Local weather will be dependent to some degree to the final track of Hurricane Larry. As Larry moves across the Atlantic Ocean (in a safe position for PR/USVI), winds will be predominantly from the east to southeast through at least Saturday, resulting in a weak steering wind flow on Thursday. This weak steering wind flow will be allowing afternoon showers to last longer than usual, increasing the threat of flooding. However, the limiting factors seem to be below- normal available moisture. In addition, a Saharan Air Layer is forecast to arrive Thursday into Friday, promoting hazy skies. A retrograding TUTT-Low moving over the Northeast Caribbean will induce surface perturbation on Saturday, increasing instability and convective activity Saturday and Sunday. Atmospheric conditions will remain favorable for the development of rain showers and thunderstorms with the arrival of a tropical wave Sunday afternoon, with its moisture lingering through Monday. && .AVIATION...VFR conds expected through the forecast period. E-NE winds of around 15KT with occasional gusts, and sea breeze variations at TJPS are expected for the rest of today. SHRA/TSRA across SW-PR but only TJMZ to be affected, which currently has a NIL TAF. Winds to decrease to 10KT or less after 07/00Z with fair weather prevailing overnight. && .MARINE...Deteriorating marine conditions are expected through mid- week as swells from Hurricane Larry will spread across the regional waters and local passages. Hazardous seas are expected across the offshore Atlantic and the waters around the Anegada Passage, extending into the coastal Atlantic waters by Wednesday. Conditions will improve by the latter half of the work week as Larry moves will north of the area and the swell weakens. In terms of coastal hazards, a high risk of rip currents is currently in effect for eastern St. Croix. The high risk is expected to extend into the northern beaches of Puerto Rico as well as the north-facing beaches of Saint Croix on Tuesday. The dangerous rip currents will continue into Thursday. High surf conditions still remain possible across the northern beaches of Puerto Rico on Wednesday as the swell direction becomes more northeasterly, resulting in higher breaking wave heights. && .PRELIMINARY POINT TEMPS/POPS... SJU 80 90 80 93 / 40 50 30 20 STT 79 89 79 90 / 40 50 30 20 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...High Rip Current Risk from Tuesday evening through Thursday afternoon for Northeast. High Rip Current Risk from Tuesday morning through Thursday afternoon for North Central-Northwest-San Juan and Vicinity. VI...High Rip Current Risk through late Wednesday night for St Croix. AM...Small Craft Advisory until 2 PM AST Tuesday for Anegada Passage Southward to 17N-Coastal Waters of Northern USVI and Culebra out 10 NM-Coastal Waters of Southern USVI Vieques and Eastern Puerto Rico out 10 NM. Small Craft Advisory until 2 AM AST Thursday for Atlantic Waters of Puerto Rico and USVI from 10 NM to 19.5N. && $$ SHORT TERM...WS LONG TERM....GL PUBLIC DESK...LIS