Saint Simons Island, GA Weather

Key Messages

For the latest NE FL and SE GA Daily Key Messages please visit: https:/www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

- Extended Duration of Coastal and Marine Hazards This Week. Coastal Flood Warning - Moderate to Locally Major Flooding around Times of High Tide Along the Atlantic Coast and Within the Intracoastal Waterway and the Entirety of the St. Johns River Basin extended through Tuesday and Wednesday. Wind Advisory for the Atlantic Coastal Counties extended through this Evening. Gale Warning for the Atlantic Waters extended through Monday Night. High Surf Advisory & High Risk for Rip Currents through most of this Week. Major Beach Erosion around Times of High Tide through most of this Week. Locally Heavy Rainfall Possible for Coastal Northeast FL through Tonight

Near Term

Main Highlights: Through Tonight

- A Coastal Flood Warning for Moderate Tidal Flooding has been Extended through Early Wednesday Morning along the Atlantic Coast and within the Intracoastal Waterway and the Entirety of the St. Johns River Basin.

- Wind Advisory Continues along the Atlantic Coast and St. Johns River through Sunday Evening for Frequent Wind Gusts of around 45 mph.

Sharp coastal troughing remains over the area with strong high pressure centered over the Mid-Atlantic states wedging down the eastern seaboard and weak Atlantic low pressure lingering to the southeast. The Wind Advisory has been extended into this evening for the gusty north-northeasterly winds along the SE GA and NE FL coasts. Wind gusts could reach up to 40-45 mph at times. Breezy conditions linger overnight with the continued tight pressure gradient. Waves of scattered coastal showers will shift onshore through the evening hours mainly for coastal NE FL, St Johns River basin and north-central FL. A few convergent bands may form along the NE FL coast bringing heavier downpours and localized flooding. If these bands coincide with high tide cycles, this could exacerbate the already significant tidal flooding expected. Shower activity wanes overnight with a few coastal showers shifting onshore mainly south of St. Augustine. Meanwhile, a drier airmass (PWATs < 1 in) will keep inland SE GA and Suwannee Valley rain-free. ...Overcast skies and breezy onshore winds will keep highs below seasonable in the low 70s along the coast to around 80 west of I-75. Overnight lows will range from the mid 50s in SE GA to the upper 60s along the NE FL coast.

Short Term

Main Highlights This Period:

- Coastal and Marine Hazards Continue, with Coastal Flood Warnings Remaining in Effect along the Atlantic Coast, Intracoastal Waterway and St. Johns River Basin. Moderate Tidal Flooding Will Continue Around Times of High Tide for these Locations.

- Wind Advisory Conditions are Likely to Continue through Monday Afternoon at Coastal Locations.

- Gale Warnings Continue for the Atlantic Waters through Monday Night.

- Dangerous and High Surf Conditions Continue, with High Surf Advisories and a High Risk for Deadly Rip Currents at All Area Beaches. Pounding Surf During High Tide Cycles Will Cause Major Beach Erosion.

A highly amplified pattern aloft will continue early this week, with a cutoff trough meandering near Bermuda, while ridging initially extending across the lower Mississippi and Tennessee Valleys shifting slowly eastward across the southeastern states, with this feature directing a series of shortwave troughs northeastward from the Desert Southwest and Rockies towards the northern Plains and the Upper Midwest. Meanwhile, a slowly weakening surface high pressure center centered over the Southern Appalachians will slowly weaken and shift southward over the southeastern states, followed by a reinforcing and strengthening high pressure center building southeastward from Ontario and Quebec towards the eastern Great Lakes and New England. Otherwise, sharp coastal troughing will remain situated over our local Atlantic waters, keeping a tight local pressure gradient in place across our area through Monday.

Long Term

Main Highlights This Period:

- Coastal Shower Coverage Increases along the I-95 Corridor as Northeasterly Winds Again Surge from late Wednesday through Friday.

Troughing aloft and low surface pressures over the Bahamas on Wednesday will finally shift northeastward and away from our region late in the week. However, reinforcing high pressure centered over New England on Wednesday morning will slowly shift offshore while wedging down the southeastern seaboard, creating another round of gusty northeasterly winds at coastal locations for the duration of the upcoming week as coastal troughing remains situated over our local Atlantic waters. This long duration wind event will maintain significant coastal and marine impacts as high astronomical tides associated with the midweek lunar perigee begin to only gradually subside by Friday and Saturday. A tightening local pressure gradient may result in another round of Wind Advisory conditions, especially for coastal northeast FL by late Wednesday and Thursday.

Coastal troughing will re-sharpen over our local waters on Wednesday, directing another surge of Atlantic moisture towards coastal northeast FL. High pressure wedging down the southeastern seaboard will strengthen low level convergence, which will advect showers occasionally onshore from the Atlantic waters across the I-95 corridor for the balance of the work week. Gusty onshore winds will keep highs mostly in the mid 70s along the I-95 corridor on Wednesday and Thursday, with upper 70s and lower 80s prevailing inland. A slightly drier air mass lingering over inland southeast GA and the Suwannee Valley will allow lows to fall to the upper 50s to near 60, while coastal lows generally remain in the 65-70 degree range.

Ridging aloft developing over the Gulf late this week will begin to build northeastward towards our region, allowing for heights to rise locally. Although multi-layered cloud cover will continue across our region, inland highs should rebound to the low and possibly mid 80s by next weekend, with coastal highs remaining in the 70s due to breezy onshore winds. Lows will trend above late October climatology by Friday and Saturday, with 60s possible area-wide by Friday and Saturday nights.