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

- Isolated Strong TStorms Tonight. Isolated Strong Storms Possible from the I-10 Corridor northward across SE GA. Hazards: Wind Gusts of 40-50 mph, Frequent Lightning & Small Hail

- Small Craft Advisories the Waters North of St. Augustine Late Tonight

- High Risk for Rip Currents at Area Beaches Tues through Wed

- Beneficial Rainfall and Isolated TStorms Tuesday through Wednesday,

- Mainly for Northeast & North Central FL. Strong Storms Possible for Portions of Northeast & North Central FL

NEAR TERM /THROUGH TUESDAY/

Main Highlights This Period:

- Scattered Thunderstorms Tonight. Strong to Isolated Severe Storms will Be Possible for Locations South of I-10. Main Thunderstorm Hazards: Strong Wind Gusts of 40-60 mph, Frequent Lightning Strikes, and Hail.

- Strengthening Northeasterly Winds are Expected Across the Atlantic Waters North of St. Augustine Late Tonight and Early Tuesday Morning. Small Craft Advisories Will Begin After Midnight Tonight for the Georgia Waters. High Risk for Rip Currentss Expected at Area Beaches on Tuesday and Wednesday.

- Beneficial Rainfall and Isolated Thunderstorms Expected to Overspread Locations Along the I-10 Corridor After Midnight Tonight.

Afternoon surface analysis depicts a cold front draped from the coastal Carolina region across southern GA and AL, with a weak wave of low pressure developing along this boundary along the northern Gulf coast. Meanwhile, strong high pressure (1028 millibars) was building over the Great Lakes in the wake of this cold front. Aloft...troughing was digging southeastward from the eastern Great Lakes towards New England and the Mid-Atlantic states, with fast zonal flow located south of this trough across the Deep South as stout ridging remains in place over the Greater Antilles and the Bahamas. A potent shortwave trough embedded within this zonal flow pattern was traversing eastern Texas, with this feature sparking a mesoscale convective system (MCS) from coastal Louisiana and Mississippi southward through central portions of the Gulf. Latest GOES-East derived Total Precipitable Water imagery indicates that deeper moisture remains in place for locations south of Interstate 10, where PWATs were generally in the 1.75 - 2 inch range, while a drier air mass was located over southeast GA, where PWAT values were mostly in the 1.25 -1.5 inch range. Widely scattered convection was developing where deeper moisture remains in place, with activity mostly over Alachua and Putnam Counties moving slowly eastward. A shallower cumulus field was located within he drier air mass for locations north of the Interstate 10 corridor, where temperatures at 19Z were generally in the 85-90 degree range, with dewpoints mostly in the mid 60s. Inland temperatures across northeast and north central FL were in the upper 80s to lower 90s, with dewpoints generally in the 65-70 range. A pinned Atlantic sea breeze boundary was slowly pushing inland from the northeast FL beaches, where dewpoints have climbed to the 70-75 range following the passage of this boundary.

Scattered convection will continue to propagate slowly eastward this afternoon through early this evening for locations along and south of the I-10 corridor. Mesoscale boundary collisions occurring in this warm, humid and unstable environment may cause storms to pulse to strong or even briefly severe levels on an isolated basis, especially later this afternoon along the I-95 corridor as convection encounters the pinned, slow moving Atlantic sea breeze boundary. Stronger storms over coastal northeast FL will be capable of producing localized downburst winds of 40-60 mph, frequent lightning strikes, heavy downpours, and hail. Activity should wane during the mid to late evening hours before the aforementioned potent shortwave trough approaches our region from the west.

Meanwhile, troughing progressing across New England and the Mid- Atlantic states this evening will move offshore by late Tuesday morning, with the front decelerating as its support aloft begins to depart. The front should cross the FL/GA border towards midnight, and the weak wave of low pressure to our west and the approaching potent shortwave trough will result in strengthening isentropic lift from west to east during the overnight and predawn hours. Our local pressure gradient will also tighten along the southeast GA coast late tonight as high pressure building towards the Mid-Atlantic states wedges down the southeastern seaboard, likely creating a surge of north to northeasterly winds before sunrise for coastal southeast GA, with this wind surge then traveling down the northeast FL coast around or after sunrise. Deeper moisture currently in place south of the I-10 corridor will shift northward tonight, and beneficial rainfall will develop during the overnight and predawn hours, mainly along and north of I-10. A few elevated thunderstorms will be possible towards sunrise as temperatures aloft cool with the approach of the potent shortwave trough. Lows tonight will range from the low/mid 60s for locations north of Waycross, with upper 60s and lower 70s expected elsewhere.

SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/

Main Highlights This Period:

- Scattered to numerous showers and isolated T'storms Tuesday and Tuesday Night Across Northeast and North Central FL. - Breezy Northeasterly Winds on Tuesday and Tuesday Evening, with Hazardous Beach Conditions and Small Craft Advisories.

- Widely Scattered T'storms Wednesday along the Atlantic Seabreeze.

A lingering stream of shortwave energy will span from the Gulf coast and across the FL peninsula on Tuesday after the passage of a frontal boundary during the early hours of Tuesday morning. This will allow for scattered to numerous, widespread at times, showers for much of the day across the area, with most activity focused along northeast FL and north central FL. With the passage of the front, winds will primarily be onshore from the northeast-east as high pressure builds along the eastern sea board. Winds from 15-20 mph, with gusts upwards to 30 mph, along coastal locations will be likely. With the onshore flow in place, the Atlantic sea breeze is expected to push inland meeting the Gulf breeze during the afternoon hours, with isolated to scattered thunderstorms developing along the mergers. With the coverage of showers and thunderstorms, temperatures are expected to be relatively cooler than Monday. Daytime highs are only expected to reach into the upper 70s along SE GA locations and the I-10 corridor, with highs in the lower to mid 80s along the rest of NE FL. Activity will persist in the overnight hours into Wednesday with coastal showers and storms lingering. Overnight Lows in the the 60s areawide, with warmer temperatures across NE FL.

By Wednesday, high pressure along the eastern seaboard will begin to weaken and push offshore ahead of an approaching frontal boundary from the northwest. Continuing easterly onshore flow will again allow for the Atlantic sea breeze to push onshore and bring chances of showers and storms as the sea breeze pushes inland with activity dwindling by the evening hours. Daytime highs will trend higher than Tuesday, with temperatures in the lower to mid 80s. By the evening hours winds will steadily shift from the southeast towards the southwest-west by Thursday morning ahead of the next cold front. Lows will again be in the 60s areawide Wednesday night.

LONG TERM /THURSDAY THROUGH MONDAY/

- Dry Conditions late this week into the Weekend.

- Above normal Temperatures this weekend.

A period of dry conditions return during the back half of this week and through the weekend as a cold front pushes into the area on Thursday. Behind the front, high pressure builds over the region and remain overhead over the upcoming weekend. There could be a few showers/storms along the sea breezes, but not expecting the same coverage as earlier in the week. Near normal temperatures during the end of the week with temperatures in the 80s, with a few locations in the 90s over north central FL. By the weekend, temperatures will rise to above normal as most locations rise above the 90F mark, with coastal locations in the 80s thanks to the onshore flow.

AVIATION /00Z TUESDAY THROUGH 00Z WEDNESDAY/

A surge of northeasterly winds is expected to arrive at SSI after 07Z, where surface speeds will become sustained at 10-15 knots, with frequent gusts of around 20 knots expected through the rest of the TAF period. Initially VFR conditions will give way to lowering ceilings and increasing chances for rainfall accompanying the wind surge as it settles southward across the Duval County terminals after 09Z, with IFR conditions overspreading SSI, JAX, CRG, and VQQ before 11Z. Strengthening north-northeasterly surface winds and lowering ceilings will arrive at SGJ and GNV after 12Z, with IFR conditions expected by 14Z. Periods of locally heavy downpours will be possible after 10Z at the regional terminals, and PROB30 groups for IFR visibilities have been inserted throughout the morning and into the afternoon hours on Tuesday.

MARINE

A cold front will cross the waters adjacent to southeast Georgia late this evening and then the northeast Florida waters during the early to mid-morning hours on Tuesday morning. A few strong thunderstorms could impact the near shore waters late this afternoon and evening, with frequent lightning strikes and briefly gusty winds possible. Showers and a few embedded thunderstorms will then overspread our local waters on Tuesday morning, with periods of heavier downpours possible through Tuesday night. Meanwhile, high pressure building over the Ohio Valley and Mid-Atlantic states in the wake of this frontal passage will send a surge of northeasterly winds down the southeastern seaboard overnight tonight through Tuesday morning, with Small Craft Advisory conditions developing initially across the Georgia waters after midnight and then expanding to the waters from St. Augustine northward early on Tuesday morning. Showers and embedded thunderstorms, along with Small Craft Advisory conditions, will continue through late Tuesday night across our local waters. Showers may linger through Wednesday before another high pressure center builds southward from the Great Lakes states late this week, signaling a drying trend that will continue across our local waters through the upcoming weekend.

Rip Currents:

A lower end moderate risk will continue through Monday evening at area beaches, with surf heights generally around 2 feet or less expected. A high risk is forecast at area beaches on Tuesday, as northeasterly winds strengthen to 20-25 mph towards sunrise at the southeast GA beaches, with this northeasterly wind surge likely arriving at the northeast FL beaches during the early to mid-morning hours. Surf heights will build to 2-3 feet on Tuesday at the southeast GA beaches and 3-4 feet at the northeast FL beaches. These surf heights will persist into Wednesday, keeping an elevated risk in place at all area beaches.

FIRE WEATHER

- High Afternoon Dispersions Thursday NEAR CRITICAL MINRH VALUES THURSDAY AND FRIDAY OVER - Inland Southeast Georgia

Scattered showers and storms will continue to develop Today and into Tonight as a cold front pushes through the area. Higher chances of showers develop on Tuesday primarily over northeast Florida. Winds will primarily be from the northeast-east on Tuesday, with stronger winds along the coast. Isolated to scattered thunderstorms are likely along the sea breeze mergers during the afternoon hours. Activity will begin to lessen by Tuesday evening, with coastal showers/storms continuing. By Wednesday isolated showers/storms are again expected along the Atlantic seabreezes over the US-17 and I-95 corridors. Dry cold front moves through Thursday, high pressure will build overhead Friday and Saturday.

Dispersions will be in the good range on Tuesday despite breezy winds due to low cloud cover, but increase Wednesday from higher mixing heights. Drier airmass arriving on Thursday and increasing transport winds ahead of and behind the dry cold front will create widespread high afternoon dispersions. MinRH values will fall to near critical levels Thursday and Friday over inland Southeast Georgia.

FOG POTENTIAL AND OTHER REMARKS: Gusty and erratic winds expected in and near thunderstorms.

PRELIMINARY POINT TEMPS/POPS

AMG 64 77 60 83 / 40 30 20 40 SSI 69 76 69 80 / 60 60 40 40 JAX 70 77 66 83 / 70 80 40 70 SGJ 72 81 69 83 / 80 80 50 70 GNV 70 82 65 86 / 70 90 20 50 OCF 70 84 67 86 / 30 80 20 50

JAX WATCHES/WARNINGS/ADVISORIES

FL...High Risk for Rip Currents from 6 AM EDT Tuesday through late Tuesday night for FLZ124-125-138-233-333. GA...High Risk for Rip Currents from 6 AM EDT Tuesday through late Tuesday night for GAZ154-166. MARINE...Small Craft Advisory from 2 AM to 9 PM EDT Tuesday for AMZ450- 470. Small Craft Advisory from 6 AM to 9 PM EDT Tuesday for AMZ452- 472.