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

- Patchy to Areas Fog Inland Areas Early on Tuesday Morning

- Daily Afternoon & Evening Thunderstorms Tues through Sun. Heavy Rainfall Potential Wed & Thurs for Northeast & North Central FL

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

UPDATE

A few showers and storms over the inland areas this evening but should fade quickly so have adjusted POPs accordingly. The light winds and the ample moisture will lead patchy fog development, especially well inland. Along the area waters and coastal zones, a few showers expected to move ashore late tonight.

NEAR TERM /UNTIL 6 AM TUESDAY MORNING/

Highlights Today and Tonight:

- Strong Storms Possible through Early this Evening for Inland Locations Along and West of U.S. Highway 301.

- Patchy to Areas of Locally Dense Fog Possible Early on Tuesday Morning at Inland Locations.

- Another Round of Coastal Showers and Thunderstorms Possible During the Predawn and Early Morning Hours Along and East of I-95.

Afternoon surface analysis depicts high pressure (1023 millibars) centered over the southern Appalachians, while coastal troughing was situated over our near shore Atlantic waters. Meanwhile, Tropical Depression #5 has been designated to the south of coastal Louisiana, with this developing tropical cyclone moving slowly west- northwestward towards the Upper Texas and southwestern Louisiana coastline. Aloft..."Heat Wave" ridging was centered over the Ozarks as well as the Tennessee and the lower Mississippi Valleys, with weak troughing otherwise situated off the southeastern seaboard. Latest GOES-East derived Total Precipitable Water imagery indicates that deep tropical moisture resides across our region, with PWATs generally in the 2 - 2.2 inch range. Downpours and embedded thunderstorms that soaked much of coastal southeast GA and coastal Nassau County, FL earlier this morning have shifted inland, with widely scattered convection progressing west-southwestward across inland portions of southeast GA and also moving very slowly westward across southern portions of the St. Johns River basin. Temperatures at 19Z were mostly in the upper 80s and lower 90s at inland locations outside of ongoing convection, while breezy onshore winds and earlier rainfall were keeping coastal temperatures mostly in the low and mid 80s. Dewpoints were generally in the 70s across our region.

A stagnant weather pattern will prevail locally through at least Tuesday, as "Heat Wave" ridging remains in place to the north of our area and a coastal trough remains situated over our local Atlantic waters. Showers and thunderstorms will likely increase in coverage and intensity later this afternoon, especially near the I-75 corridor in the Suwannee Valley and north central FL, where mesoscale boundaries will collide and potentially result in a few storms "pulsing" and becoming strong, with downburst winds of 35-45 mph possible, along with frequent lightning strikes and heavy downpours. Downpours could potentially train over portions of the I- 75 corridor, with some potential for localized flooding in urban areas such as Gainesville or Ocala through around sunset this evening before activity shifts west of the Suwannee River early this evening. Debris cloud cover should thin out around or shortly after midnight, potentially setting the stage for another round of low stratus and locally dense fog at inland locations west of the U.S. Highway 301 corridor towards sunrise on Tuesday. Lows will fall to the low and mid 70s at inland locations, with a light onshore breeze keeping coastal lows mostly in the upper 70s.

Coastal troughing should generate another round of showers and embedded thunderstorms over our adjacent Atlantic waters after midnight, with this activity potentially advecting onshore towards the coastal counties during the predawn and early to mid morning hours on Tuesday. Briefly heavy downpours will be possible during this time frame, generally for locations along and east of the Interstate 95 corridor.

SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/

- Daily Thunderstorm Potential - Low Flooding Rain Risk Inland Northeast Florida

Pattern for initially onshore morning showers and thunderstorms, developing further inland in the afternoon and evening hours, will continue through midweek as high pressure to the north drifts slowly towards to the east and offshore troughing moves inland over southeast Georgia and northeast Florida, shifting the prevailing flow to become more southerly by then end of the period. PWAT values are expected to rise to levels as high as 2.5 inches which can lead to storms capable of producing heavy rainfall and localized flooding. Patchy inland late night fog will also be possible each night and into the early morning hours. High temperatures through midweek will rise into the upper 80s and lower 90s with lower temps occurring in coastal counties and adjacent areas as onshore flow pushes the east coast diurnal sea breeze further inland. 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 for some areas during this period.

LONG TERM /THURSDAY THROUGH MONDAY/

Main Highlights This Period:

- Daily Thunderstorms, Isolated Strong Storms Possible Inland - Increased Rip Current Risk Possible Mid to Late Week

High pressure along the coast will drift towards the south and west towards the gulf, resulting in a more westerly-northwesterly flow for the beginning of the weekend, with diurnal bouts of convection potentially becoming less intense on Saturday and Sunday. Slightly above average temperatures will continue through the end of the week and into the weekend with daily max temps rising into the lower to mid 90s. Heat index values will rise to be over 100 during this period and a chance for rising to heat advisory criteria through this period cannot be ruled out.

AVIATION /00Z TUESDAY THROUGH 00Z WEDNESDAY/

VFR clouds prevail at this time and may continue until about 05z. There are a few more low clouds at about 1-2 kft this evening and can't rule out a fairly short period of MVFR cigs for coastal TAFs. After 05z/06z, chances of IFR to MVFR conditions increase as low clouds and some vsby restrictions develop, especially for VQQ and GNV. There may be some better low cig/vsby chances now for JAX from about 08z-12z, but for now given the uncertainty showed a scattered stratus deck and 6SM BR.

Additionally, isolated to scattered showers are likely to develop over the near shore Atlantic waters during the predawn hours on Tuesday and may approach the SGJ and SSI coastal terminals and CRG after 08Z, and a PROB30 group for MVFR conditions during heavier downpours was inserted through around 14Z. VFR conditions will prevail elsewhere at the inland terminals by 14Z, although periods of MVFR ceilings may then develop towards 15Z. Another round of scattered showers and storms expected about 16z-19z for coastal TAFs and then around 17z-21z for GNV. The PROB30 convective groups used for coastal TAFs, and TEMPO for GNV, with the latter TAF having higher rain chances.

MARINE

Weak coastal troughing remaining situated over our near shore Atlantic waters through mid week. Showers and embedded thunderstorms will likely redevelop across our local waters tonight through Tuesday, mainly overnight and morning hours, with decreasing coverage during the afternoon hours as activity shifts inland. Showers and thunderstorms will then increase in coverage throughout our local waters on Thursday and Friday as another trough progresses westward from the Atlantic waters across our region. Onshore winds will prevail through Saturday, followed by winds shifting to westerly by Saturday night and Sunday as a frontal boundary enters the southeast states. Several rounds of showers and thunderstorms are possible during the upcoming weekend ahead of this frontal boundary.

Rip Currents: Breezy onshore winds will persist through Tuesday, with breakers of 2-3 feet keeping a moderate rip current risk in place at all area beaches. A high risk is possible towards Wednesday at the northeast FL beaches due to this persistent onshore flow, with a higher end moderate risk otherwise forecast at all area beaches later this week.

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 73 91 72 90 / 20 30 10 50 SSI 77 87 78 87 / 20 40 30 50 JAX 74 89 74 89 / 20 40 40 70 SGJ 77 87 76 87 / 30 50 40 70 GNV 74 89 73 89 / 20 80 20 90 OCF 74 89 73 89 / 30 70 20 90

JAX WATCHES/WARNINGS/ADVISORIES

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