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

- High Risk for Rip Currents Continues at the Northeast Florida Beaches. Moderate Risk at Southeast GA Beaches

- Scattered Thunderstorms Inland Late This Afternoon and Evening. Main Hazard Area: Inland Locations Along U.S.-301

- Waves of Showers and Thunderstorms Beginning on Thursday. Heavy Rainfall and Localized Flooding will be a Concern. Widespread 2-4 Rainfall Totals Forecast through Tuesday

- Hot and Humid - Daily Heat Index 95- 105F through Friday

NEAR TERM /THROUGH TONIGHT/

Main Highlights This Period:

- High Risk for Rip Currents Continues Today for NE FL Beaches

- Scattered Thunderstorms will be capable of very Heavy Downpours which may lead to Localized Flooding this evening along US 301.

The stagnant pattern will begin to budge today as the low level Bermuda ridge axis begins to drift southward as a front presses into the Tennessee River Valley. As this happens, steering flow will gradually turn south-southwesterly this afternoon. This will tap into a rich, tropical moisture source in the Gulf, helping fuel afternoon and evening convection through the late afternoon and evening. The shifting flow pattern will slow the Atlantic sea breeze as it moves inland, allowing more late afternoon storms along the I- 95 corridor before it pushes farther inland, beyond the US 301 corridor, and merges with the Gulf sea breeze. Higher moisture will bring a renewed chance for locally heavy rainfall with the stronger thunderstorms, which may result in minor flood concerns especially in urban and flood-prone areas today.

The mid-summer like heat will continue this afternoon with highs reaching the low 90s in many areas before convection initiates on the sea breeze. The humid (70s dewpoints) will make it feel like the low 100s in many areas this afternoon - stay hydrated and take breaks when working outside.

After sunset coverage will dwindle some with the loss of heating but an upper impulse may keep scattered showers going late into the night. As the wave aloft passes over head, southwesterly flow will become more dominant during the early Thursday morning hours and likely begin to push weakening showers into the Suwannee River corridor through sunrise. Mild, muggy overnight conditions are expected with lows in the low 70s. Lighter winds inland may lead to patchy fog Thursday AM in areas that receive beneficial rain this afternoon and evening.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/

- Waves of Showers and Thunderstorms Overspread Our Region from South to North Beginning on Thursday.

- Strong storm potential on Thursday afternoon along the I-95 corridor.

- Heat index 95-105 degrees for portions of our area during the afternoon hours on Thursday and Friday.

Showers and storms capable of producing heavy rainfall will develop on Thursday and Friday as moist air is drawn in from out of the gulf, raising PWAT levels upwards of 2.0 to 2.5 inches as high pressure ridging withdraws to the east. Heavy downpours associated with stronger and slower moving storms will be capable of causing localized flooding. High temperatures through the end of the week will rise into the upper 80s and lower 90s with Heat Index values in the upper 90s and even reaching over 100 degrees in some areas. Overnight low temperatures will drop down into the upper 60s over inland southeast Georgia and in the lower 70s for northeast Florida and for areas along the coast.

LONG TERM /SATURDAY THROUGH TUESDAY/

- Waves of Showers and Thunderstorms Expected to Continue, with Beneficial Rainfall Totals Forecast Area-Wide.

- Clouds and Cooler Temperatures Expected Early Next Week.

Bouts of showers and thunderstorms are expected to continue through Saturday and Sunday as prevailing flow over the region shifts to become more westerly as a frontal boundary to the north is anticipated to stall in the vicinity of Georgia. Pattern will continue on into Monday and Tuesday with convective activity and rains likely to strengthen in conjunction with upper level instability crossing over the forecast area. Temperatures are expected to dip to be near and slightly below the seasonal average through the weekend and into next week.

AVIATION /06Z WEDNESDAY THROUGH 06Z THURSDAY/

A mix of VFR and MVFR ceilings will continue through around 12z with lower cigs breaking up and lifting through the morning hours. Breezy southeasterly winds will continue ahead of the Atlantic sea breeze this morning and early afternoon, with gusts up to 20 knots at the coastal terminals (KSSI/KSGJ). The Atlantic sea breeze will push inland around 16z and reach KJAX around 19z-20z. At this time, interaction with St Johns River breeze will initiate vicinity showers with strengthening convection and possible TSRA impacts after 20z for inland terminals along the I-95 corridor. After sunset, convective activity will diminish in coverage but an weak passing disturbance will keep vicinity showers in the forecast during the late evening hours for all terminals.

MARINE

Bermuda high pressure will be dominant again through Thursday night. An incoming cold front will push the high pressure southward through the end of the week as front itself stall just north of the waters until Sunday. Breezy south southeasterly winds will increase again to Exercise Caution levels which will keep thunderstorm activity inland. By Thursday and through the weekend, offshore flow will set up, pinning the Atlantic sea breeze near the coast and increasing chances for afternoon thunderstorms across the area waters. A wet pattern continues this weekend into next week as weak low pressure moves along a stalled front to the north. As the low moves away early next week, a surge of northeasterly winds may push into the local waters bringing a period of Small Craft Advisory conditions.

Rip Currents:

One more day of breezy south-southeasterly winds and breakers elevated to around 3-5 feet will result in a High Risk of Rip Currents for northeast FL beaches. Slightly lower surf 2-4 feet for the southeast GA beaches will keep risk at Moderate levels today. Offshore flow will begin to decrease risk Thursday and through the Weekend.

FIRE WEATHER

A breezy southeasterly wind continues today ahead of the sea breezes this afternoon. The Gulf breeze will make it farther inland today, reaching I-75 early this evening, between 5-6 PM. Meanwhile, the Atlantic sea breeze will be slowed by increasing southwesterly transport winds, reaching the I-95 corridor around 3-4 PM. The two sea breezes will merge near the US 301 corridor where scattered to numerous showers and thunderstorms will develop. Anticipate showers and isolated storms to continue into the late evening and overnight into the early morning hours Thursday. Breezy winds are expected with the easterly sea breeze, with gusts around 15-20 mph. Widespread waves of downpours are forecast area-wide from Friday through the weekend, which may be followed by a late season cool front early next week.

FOG POTENTIAL AND OTHER REMARKS: Significant fog is not expected into early next week, but patchy morning fog will be possible in areas where heavy rain fell during the previous afternoon. Erratic winds are expected during periods of thunderstorms.

PRELIMINARY POINT TEMPS/POPS

AMG 87 69 86 69 / 60 30 50 30 SSI 88 75 89 74 / 40 40 60 40 JAX 92 73 91 72 / 60 40 70 40 SGJ 90 74 90 73 / 40 40 70 40 GNV 92 72 88 71 / 30 40 80 30 OCF 90 73 87 72 / 40 50 80 20

JAX WATCHES/WARNINGS/ADVISORIES

FL...High Risk for Rip Currents through this evening for FLZ124-125-138- 233-333. GA...None. MARINE...None.