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

- Scattered to Numerous Afternoon & Evening TStorms Each Day capable of locally heavy rain and flooding. Isolated strong storms possible.

- Moderate Rip Current Risk Continues at All Area Beaches

NEAR TERM /THROUGH TONIGHT/

Highlights through Tonight:

- Isolated strong thunderstorms with locally gusty winds and heavy downpours is expected across SE GA early this afternoon and along the I-95 corridor during the late afternoon.

A wavy stalled frontal zone remains to the north today while troughing exists aloft. Similar to yesterday, a mellow low level steering flow will favor a southwesterly direction through most of the day, which will pin and slow the Atlantic sea breeze as it develops.

There appears to be a higher chance of more isolated coverage during the morning and early afternoon hours across eastern and southern zones of NE FL as a wedge of drier air over the eastern Gulf advects northward. Further north, high precipitable water (2"+) will fuel convection across SE GA and the Suwannee River valley early in the day, with thunderstorms developing along the Big Bend and pushing into the Suwannee River during the late morning hours. As more deeper moisture builds and outflows from the west begin to interact with the Atlantic sea breeze during the late afternoon and early evening scattered thunderstorms will develop and likely propagate southwestward as storm- relative inflow trends southerly. With the loss of daytime heating, there will be a quick decline in thunderstorm activity this evening.

Primary concerns with today's storm activity will be gusty outflow winds and locally heavy rainfall which may lead to flooding, particularly in low-lying, poor-drainage, or generally flood-prone locations.

Temperatures will have more time to heat up today, especially across NE FL and North Central FL, with highs pushing into the low 90s. The earlier start to convection for the Suwannee Valley and north into SE GA will limit todays highs to the upper 80s or right at 90 degrees due to the rain-cooled air and mostly cloudy conditions. Overall this will keep heat index in the upper 90s to low 100s this afternoon. A standard mild, muggy night will follow todays typical August heat as temperatures fall to the low 70s.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/

Main Highlights This Period:

- Chance for a isolated strong to severe storms each afternoon and evening Thursday & Friday

Summertime pattern for diurnal bouts of showers and thunderstorms will continue through the end of the week as a prevailing southwesterly flow remains in place between the frontal zone to the north and high pressure ridging extending over Florida from out of the east. Daytime high temperatures will be in the lower 90s for inland areas on Thursday and Friday, with max temps in the upper 80s and lower 90s along the coast. Overnight low temperatures will drop down into the lower 70s over inland areas and in the mid 70s for areas along the coast and near the St Johns River. Heat index values will rise to be over 100 during this period with a potential for some areas to reach heat advisory levels on Wednesday. The passage of upper level short waves through this period could lead to stronger thunderstorm developments in the afternoon and evening hours.

LONG TERM /SATURDAY THROUGH TUESDAY/

Main Highlights This Period:

- Chances For Isolated Strong to Severe Storms Continues Each Afternoon and Evening

Prevailing flow will shift about to become more out of the southwest and west by the end of the weekend and into next week as the frontal zone to the north becomes less defined and high pressure builds in closer to the southeast US. Otherwise, the pattern for diurnal showers and storms will remain fairly consistent through the period with the potential for stronger storms occurring with possible passing upper level short waves. Temperatures will trend slightly above average through the weekend and into the beginning of next week with daily high temperatures reaching into the lower 90s. Heat index values will rise to be over 100 during this period but are expected to remain below heat advisory criteria each day.

AVIATION /06Z WEDNESDAY THROUGH 06Z THURSDAY/

Persistent high clouds will limit the potential for low stratus/light fog development this morning. However, terminals that received heavy rain yesterday, such as KJAX, may still see brief scattered low cloud around sunrise. Otherwise, VFR conditions are generally expected throughout the day and into the evening, barring influence from afternoon thunderstorms. Probabilities continue to rise regarding afternoon convection along the I-95 corridor after 18z this afternoon. Activity will gradually develop westward through the evening hours with showers lingering the longest at KGNV, possibly until 02z. Southwesterly winds will prevail this morning with the Atlantic sea breeze southeasterly wind influence at KCRG/KSSI/KSGJ around 17-19z.

MARINE

A stalled frontal boundary positioned just north of the Georgia waters will remain in place during the next several days. Thunderstorms developing over coastal locations will push across our local waters through the upcoming weekend, mainly during the late afternoon and evening hours, with strong to isolated severe storms possible. Offshore winds will otherwise prevail during the overnight and morning hours, with the Atlantic sea breeze shifting winds to onshore each afternoon across the near shore waters. Southerly winds will then surge each evening, with speeds briefly approaching Caution speeds around sunset outside of ongoing thunderstorm activity. Stronger high pressure building over New England this weekend will shift prevailing winds to onshore across our local waters.

Rip Currents: Following the sea breeze a lower end Moderate Risk is expected at all area beaches each afternoon during the next through the end of the week.

FIRE WEATHER

A frontal zone will remain nearly stationary across southern GA through the end of the week, persisting elevated chances for showers and thunderstorms each day, mainly during the daytime hours. Weak high pressure ridging across and just south of the region will keep the flow direction generally out of the south to southwest, with winds peaking during the evening and overnight hours. Another frontal boundary drops southward towards area waters this upcoming weekend, maintaining an active pattern.

Fog Potential: Significant fog is unlikely over the next several days. Gusty and erratic winds can be expected in and near thunderstorms.

PRELIMINARY POINT TEMPS/POPS

AMG 91 72 92 72 / 60 30 60 30 SSI 88 76 89 76 / 40 20 50 30 JAX 91 72 91 72 / 50 30 60 20 SGJ 90 73 90 74 / 50 20 50 20 GNV 90 71 91 72 / 30 30 60 20 OCF 92 72 91 72 / 40 40 70 20

JAX WATCHES/WARNINGS/ADVISORIES

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