textproduct: Jacksonville

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

- Areas of Locally Dense Fog Inland Early this Morning. Main Impact Areas: Inland Northeast and North Central FL.

- Daily Afternoon & Evening Thunderstorms This Week. Storm Hazards: Lightning, Localized Flooding and Briefly Gusty Winds. Main Impact Areas Today: Locations West of I-95. Heavy Rainfall Potential Increases Thurs for Northeast and North Central FL.

- Moderate Rip Current Risk at All Area Beaches. High Risk Possible at the Northeast FL Beaches Later this Week.

NEAR TERM /THROUGH TONIGHT/

Highlights Today and Tonight:

- Heavy rainfall/localized flooding remains the main threat from thunderstorm activity today, mainly over inland areas.

Onshore/Easterly steering flow along with deep tropical moisture already in place with PWATs around 2 inches will lead to another day with morning showers/isolated storms along the Atlantic Coastal areas translating to inland areas through the afternoon hours with the East Coast sea breeze pushing this activity well inland, then ending around sunset over far inland areas, then scattered showers and isolated storms re-developing again later tonight over the Atlantic Coastal waters and pushing towards the coast by sunrise Tuesday morning. Main threat from storms will continue to be heavy rainfall/localized flood threat from slow moving storms along with isolated strong storms with gusty winds to 40-50 mph and frequent lightning. This threat will be highest during peak heating during the afternoon hours, but heavy downpours will be possible at any time with thunderstorm activity. Max temps will be in the upper 80s to near 90F along the Atlantic Coast and I-95 corridor and into the lower 90s over inland areas, which will result in peak heat indices in the 100-105F range. Low temps still in the lower/middle 70s inland and upper 70s along the Atlantic Coast. Low clouds/stratus and patchy fog will be the main issue towards sunrise over inland areas, but widespread dense fog is not expected either morning.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/

- Daily Thunderstorm Potential Continues. - Low Flooding Rain Risk for Inland Northeast Florida.

A similar pattern will continue for Tuesday and heading into mid week as a high pressure system from the surface up to about 700 mb remains centered from about east TN to NC while moving little through the short term, and coastal troughing lingers east of the Florida Peninsula. This will continue prevailing east and southeast low level flow. Guidance is in agreement regarding some more excited shortwave energy/mid level waves moving westward along the southern periphery of high pressure ridging, helping to enhance coverage of showers and storms as PoPs peak in the 70-90 percent range both Tuesday and Wednesday combined with PWATs exceeding 2 inches.

The general trend will continue to be morning morning convection over area waters and near the coast transitioning inland during the afternoon and evening with the east coast sea breeze. The HWY 301 to I-75 corridor over northeast FL is expected to continue being the hot spot of sorts for more enhanced convection potential and heavy rainfall/localized flooding potential as the easterly flow reaches the Gulf Sea breeze. Rain chances should tapper off inland each night around the 10 pm to midnight time frame, then resurrect to an extent near the Atlantic coast overnight with easterly flow. Patchy inland late night fog will also be possible each night and into the early morning hours.

Temperatures will be near to slightly above average this period with highs in the upper 80s along the Atlantic coast and parts of the St. Johns River basin to lower 90s inland. Muggy overnight lows will range in the lower to mid 70s, and likely upper 70s at the coast.

LONG TERM /THURSDAY THROUGH SUNDAY/

Main Highlights This Period:

- Daily Thunderstorms Continue, Isolated Strong Storms Possible Inland.

- Increased Rip Current Risk Possible Mid to Late Week.

The synoptic pattern through the extended forecast does not change much mid to late week with a surface to mid level ridge staying just to the north of the area maintaining a prevailing easterly flow. Some changes do not appear likely until about the Friday to Saturday time frame, as rather stacked high finally starts to slide towards east of the region in response to an upper trough that dives into the northeastern states.

The one other feature that we will monitor is the remnants of Dolly, as this tropical wave moves across the Bahamas and towards the Florida Straits into the Gulf mid to late week. The latest NHC Tropical Weather Outlook continues to only have a 10 percent of development over the next 7 days for this system. While some indirect impact is possible with additional tropical- like moisture that could move into northeast FL by the weekend, confidence is not high. Additionally, with the continued easterly flow and some relatively weak easterly swells, an elevated rip current risk is expected to continue.

Temperatures will trend slightly above average during the long term period, especially inland with more onshore flow.

AVIATION /12Z MONDAY THROUGH 12Z TUESDAY/

LIFR conditions at GNV will gradually improve to IFR towards 14Z and then MVFR by 15Z. Meanwhile, periods of showers will continue to impact SSI through around 15Z, with IFR conditions expected during heavier downpours. Brief periods of MVFR ceilings will otherwise be possible through around 16Z at the rest of the northeast FL terminals. Showers and thunderstorms are then expected to develop along the I-95 corridor towards 17Z, with activity shifting inland towards the VQQ and GNV terminals after 18Z. Confidence for significant impacts is highest at GNV, where a TEMPO group for brief surface wind gusts up to 30 knots and IFR conditions during heavier downpours was inserted after 20Z through 00Z. PROB30 groups for brief surface wind gusts up to 25 knots and MVFR conditions during heavier downpours were maintained at the rest of the terminals after 15Z. VFR conditions are expected to prevail by 01Z Tuesday. Showers developing over the near shore Atlantic waters during the predawn hours on Tuesday may approach the SGJ and SSI coastal terminals after 07Z, but confidence remains too low for anything other than vicinity shower coverage at this time. Northeast to easterly surface winds will become sustained at 5-10 knots by 15Z at the inland terminals, while speeds increase to around 10 knots at the SSI and SGJ coastal terminals. Surface winds will then gradually diminish after 23Z this evening.

MARINE

Onshore flow will continue through the week as a mid level ridge remains north of the local waters. This will allow for offshore showers to push towards coastal locations each morning, then onshore as the sea breeze pushes inland. Small craft advisories are not expected during the upcoming week.

Rip Currents: Solid Moderate risk through most of the upcoming week with surf/breakers of 2-3 feet in the continued onshore flow.

FIRE WEATHER

A similar pattern continues to dominate the area through at least the next several days, featuring east to southeast winds and morning coastal showers following by more amplified showers and thunderstorms in the afternoon and evening with daytime heating. The best chance for strong thunderstorms will be generally towards Highway 301 to I-75 and areas further west. Outside of rainfall, dispersions will be only in the poor to fair range thanks to the onshore flow and weaker winds aloft. Best dispersions and transport winds will be found the further west/northwest you go.

Fog Potential: Gusty and erratic winds can be expected in and near thunderstorms with briefly localized flooding rainfall. Late night and early morning patchy fog and low stratus will be possible, especially in areas that received more rainfall.

PRELIMINARY POINT TEMPS/POPS

AMG 90 72 90 72 / 50 20 70 0 SSI 85 76 87 77 / 50 30 60 20 JAX 89 74 88 74 / 50 30 60 20 SGJ 88 75 87 75 / 40 30 60 20 GNV 91 73 89 73 / 70 40 80 20 OCF 92 73 90 73 / 70 30 70 20

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...None. MARINE...None.