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

- Strong to Isolated Severe Thunderstorms Possible Today. Isolated Severe Storm Potential for Locations South of Waycross, GA. Storm Hazards: Damaging Wind Gusts of 40-60 mph, Frequent Lightning, Hail & Isolated Tornadoes, and Locally Heavy Downpours. Rainfall Amounts Generally in the 0.5 to 1.5 Range, with Heavier Totals Possible Across Inland Southeast GA

- Moderate Risk of Rip Currents Continues at Area Beaches

- Windy with Scattered Thunderstorms Possible on Thursday

- Extreme to Exceptional Drought Conditions Continue for Most of Our Area

UPDATE

Showers continue to move across southeast Georgia, with occasional isolated thunder. Lack of instability across Georgia is suppressing chances for strong storms this morning. So far, rainfall totals over inland southeast Georgia this morning are around 1 inch. As activity moves southeastward later this morning and into the afternoon, expect an uptick in thunderstorm activity and increased risk for strong to severe thunderstorms over northeast FL. A layer of increased surface CAPE and helicity along and south of I-10 will continue to promote isolated tornado chances late this morning through the early afternoon, however damaging winds remain the primary threat today. Outside of storms today, breezy southwesterly winds will be present across most of the area. Ahead of convection, areas south of Gainesville/St. Augustine will reach the 80s to low 90s while locations north of Waycross stay in the 60s.

NEAR TERM /THROUGH TONIGHT/

Main Highlights This Period:

- Strong to Isolated Severe Thunderstorms Possible Late this Morning through this Afternoon for Locations South of Waycross, GA. Potential Storm Hazards Include Damaging Wind Gusts of 40-60 MPH, Frequent Lightning Strikes, and Heavy Downpours. Lower Probabilities Exist for Tornadoes and Hail.

- Rainfall Amounts Today Will Generally Range from 0.5" to 1.5", with Locally Higher Totals Possible Across Southeast GA.

- Moderate Risk of Rip Currents at All Area Beaches.

Overnight surface analysis depicts a wave of low pressure (1005 millibars) developing along the northern Gulf coast along a stationary frontal boundary that extends across north central FL. Meanwhile, high pressure (1023 millibars) was building southeastward from the Northern Plains states towards the Upper Midwest. Aloft...a weakening shortwave trough traversing the southern branch of the jet stream across the lower Mississippi Valley was being absorbed by a potent shortwave trough that was digging east-southeastward across the Mid-Mississippi Valley towards the Ohio and Tennessee Valleys. Otherwise, a 160-knot jet streak situated at 250 millibars (around 35,000 feet) was positioned along the Mid-Atlantic coast, placing our region in an area of increasingly diffluent flow aloft. This weather pattern has strengthened isentropic lift north of the stationary frontal boundary for locations in interior southeast GA, where moderate to occasionally heavy showers were impacting locations north and west of Waycross. Multi-layeered cloud cover was otherwise in place area-wide, with a few reports of lower stratus for areas south of Interstate 10. Rainfall has dropped temperatures to to the mid and upper 50s for locations north and west of Waycross in southeast GA, while temperatures elsewhere remain in the 60s, except around 70 for coastal northeast FL, with dewpoints generally in the 60s outside of rain cooled locations.

The wave of low pressure developing along the stationary frontal boundary extending from the northern Gulf coast eastward across north central FL will progress quickly eastward this morning, crossing locations just south of Interstate 10 from the late morning through early afternoon hours before moving offshore by mid- afternoon. Strong isentropic lift will continue through early afternoon, compliments of the aforementioned jet streak situated off the Mid-Atlantic coast. Rainfall and thick multi-layered cloud cover should keep the threat for thunderstorms minimal for locations north of Waycross, and model soundings suggest that surface-basd CAPE will remain along or south of I-10 later this morning through the early to mid-afternoon. A 40-50 knot low level west-southwesterly jet will develop over locations along and south of I-10 by the late morning and early afternoon hours as the wave of low pressure traverses the area, with this feature likely strengthening convection that will overspread northeast and north central FL. Strong to isolated severe thunderstorms will be possible from around 11 AM through 4 PM, mainly for locations along and south of I-10. Strong to isolated severe thunderstorms that develop in this environment will be capable of producing downburst wind gusts of 40-60 mph, frequent lightning strikes, and heavy downpours. The Storm Prediction Center has maintained a "Slight" Risk for severe thunderstorm development for locations south of Waycross today. The presence of the frontal boundary will keep low probabilities for isolated tornadoes in place in the Slight Risk area, with bulk shear values of 50-60 knots also providing for low probabilities for large hail as well.

Periods of moderate to heavy rainfall and possibly a few embedded elevated thunderstorms this morning across inland portions of southeast GA will likely result in widespread and beneficial rainfall totals around 1 inch, with localized totals of around 2 inches. With the front remaining south of these locations and cloud cover remaining widespread through around sunset, highs will remain in the 60s for locations north of Waycross this afternoon. Rainfall totals elsewhere will generally range from 0.5" to 1 inch, with localized heavier totals possible where stronger thunderstorms develop. Highs elsewhere north of I-10 should climb to around 70, while 80s are forecast for areas south of I-10, and locations in Marion and Flagler Counties could reach 90 degrees. Breezy to windy conditions are also likely to develop in advance of the arrival of showers and thunderstorms this afternoon across north central FL, where sustained speeds of 20-25 mph with frequent 30-35 mph gusts can be expected towards noon today.

Cloud cover will decrease from north to south this evening as low pressure strengthens off the southeastern seaboard while accelerating northeastward, dragging a cold front southward through the FL peninsula. Cold air advection and decreasing northwesterly winds could allow for lower stratus clouds to develop towards sunrise across inland southeast GA and northern portions of the Suwannee Valley, where lows will fall to the upper 40s to around 50. Lows elsewhere are forecast to fall into the 50s by the predawn and early morning hours on Sunday.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Main Highlights This Period:

- Brief cool down on Sunday - Temperatures begin to warm up once again on Monday

This period will be relatively quiet as dry and cooler conditions develop on Sunday. Northerly to northeasterly winds will develop as high pressure builds overhead on Sunday and remain over the area into the upcoming week behind the cold front's passage. Clear skies with cooler temperatures will be in place on Sunday, as temperatures will be below normal temperatures as highs will be in the 70s, with lower 70s across SE GA and upper 70s across NE FL. Come Monday, northeasterly to easterly winds develop as temperatures begin to progressively warm up through the upcoming week. Daytime highs will be in the 80s, with cooler temperatures along the coast as the sea breeze will keep coastal locations cooler in the upper 70s. Overnight Lows will be in the 50s both nights, with warmer temperatures along the coast in the 60s.

LONG TERM /TUESDAY THROUGH FRIDAY/

Main Highlights This Period:

- Dry and warm weather into midweek - Next chance for widespread rainfall around late week

Slowly eastward shifting high pressure over the area will keep things quiet during the early portion of the upcoming week. A gradual warming will continue into midweek as warm air from the south advects into the area. Highs begin the period in the upper 80s, rising to lower 90s by Wednesday. As the next frontal system approaches the area, chances of showers return late Wednesday/early Thursday. With the front, temperatures look to trend down back to below the 90 mark during the back half of the upcoming week.

AVIATION /12Z SATURDAY THROUGH 12Z SUNDAY/

VFR conditions will prevail at the regional terminals through at least 11Z. Light showers should approach the SSI terminal towards 12Z, with ceilings expected to deteriorate to MVFR levels of 1,500 - 2,500 feet before 13Z. Heavier showers and a few embedded thunderstorms will then overspread SSI after 14Z, with ceilings likely lowering to IFR. Ceilings are forecast to lower to MVFR at the northeast FL terminals after 13Z, with showers and thunderstorms then impacting the terminals after 15Z, when periods of IFR conditions will be possible. Strong to severe storms are possible, generally during the 16Z-20Z time frame. Heavier showers should depart SSI through around 20Z, with stronger storms being capable of producing downburst wind gusts of 35 knots or higher.

Lingering showers should depart the regional terminals before 00Z, with ceilings at SSI lifting to MVFR towards 21Z and towards 22Z at the northeast FL terminals. VFR conditions are then expected by 04Z Sunday. Light north to northeasterly surface winds will prevail at the terminals overnight, with winds then shifting to southwesterly by 15Z at the northeast FL terminals, where sustained speeds will increase to around 15 knots and gusty. Surface winds will remain north to northeasterly through around 16Z at SSI, where speeds will increase to around 10 knots by 15Z. Surface winds will then shift to northwesterly by 22z at the regional terminals, with speeds of 10-15 knots prevailing through around 02Z. Speeds will then diminish to 5- 10 knots towards 05Z Sunday.

MARINE

Low pressure developing along a frontal boundary situated along the northern Gulf coast will push across our local waters early this afternoon. Widespread showers and thunderstorms will overspread our local waters during the late morning and afternoon hours, with strong to isolated severe storms possible through around sunset. Stronger storms will be capable of producing strong wind gusts, frequent lightning strikes, and possibly a few waterspouts. Southwesterly winds will strengthen after sunrise, with speeds likely reaching Caution levels as winds shift to westerly and then northwesterly this afternoon. The front will shift south of our area tonight, with gusty northerly winds expected after midnight as lingering showers depart the northeast Florida waters. Breezy northeast winds are then expected on Sunday as high pressure builds into the southeastern states, with diminishing winds and seas expected by early Sunday evening.

High pressure will shift offshore of the southeastern states early next week, allowing for prevailing southeasterly winds. Breezy conditions are likely on Wednesday afternoon well in advance of a cold front that will be entering the southeastern states, with Caution level speeds possible through Thursday as winds shift to southerly and then southwesterly. Showers and thunderstorms will likely accompany this next frontal passage on Thursday afternoon and evening.

Rip Currents:

A long period east-northeasterly swell will be slow to fade today, keeping a moderate risk in place at all area beaches. Breezy north- northeasterly winds and building surf on Sunday will create a higher end moderate risk, with a high risk possible at the northeast FL beaches. Persistent onshore winds early next week will keep a higher end moderate risk in place at area beaches, with a high risk possible towards midweek at the northeast FL beaches as southeasterly winds strengthen.

FIRE WEATHER

- Areas Of High Daytime Dispersions Over Northeast Fl Today

- Areas Of High Dispersions By Midweek

- Isolated Severe Thunderstorms Possible Today

A cold front will push through the area Today, bringing showers and t'storms, with chances for strong to severe t'storms from the morning to afternoon hours. Gusts to around 40-60 mph will be possible in any storms as well as frequent lightning and downpours. Higher dispersions are expected over north central FL this afternoon. By Sunday, conditions begin to dry out behind the front. With dry air filtering in behind the front, elevated fire danger conditions will be possible over inland locations. Generally drier conditions and lighter winds will then be expected for the beginning of the next work week, with minRH near critical for inland parts of the region. Elevated mixing heights by Tuesday and through midweek will bring the chance for areas of high dispersions across inland locations.

FOG POTENTIAL AND OTHER REMARKS: More erratic winds will be likely at times associated with showers and t'storms Today.

PRELIMINARY POINT TEMPS/POPS

AMG 69 49 77 49 / 100 10 0 0 SSI 73 54 73 60 / 90 30 0 0 JAX 79 53 75 53 / 90 30 0 0 SGJ 86 58 75 59 / 90 50 0 0 GNV 83 55 80 53 / 90 40 0 0 OCF 86 56 81 54 / 80 50 0 0

JAX WATCHES/WARNINGS/ADVISORIES

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