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

- Wet Pattern Continues through Tuesday with Waves of Showers and Embedded Thunderstorms Forecast Area-Wide. Stronger Storm Hazards Late this Afternoon and Early this Evening: Wind Gusts of 40-50 mph, Frequent Lightning Strikes, and Localized Flooding.

- Enhanced Rip Current Risk Begins Sunday and Continues Next Week.

- Drying Trend Takes Shape Towards Midweek, with Breezy Onshore Winds and Small Craft Advisory Conditions Possible for the Offshore Waters.

NEAR TERM /THROUGH TONIGHT/

Main Highlights This Period:

- Increasing Coverage of Showers and Thunderstorms this Afternoon and Evening. Isolated Strong Storms are Possible. Main Hazards: Heavy Downpours and Localized Flooding, Frequent Lightning Strikes, and Wind Gusts of 40-50 mph.

Afternoon surface analysis depicts a remnant, decaying frontal boundary positioned near the FL/GA border. Meanwhile, high pressure building southward from Hudson Bay, Canada, was pushing a cold front southward through the Carolinas and the Tennessee Valley. Aloft...a potent shortwave trough located near coastal New England was digging a longwave trough from the eastern Great Lakes eastward across the the Mid-Atlantic states. Otherwise, deep and unstable west- northwesterly flow aloft prevails locally in the wake of a shortwave trough that was progressing eastward off the Carolina coast. Latest GOES-East derived Total Precipitable Water imagery indicates that deep tropical moisture remains in place across most of our area, with PWATs generally ranging from 1.9 - 2.1 inches. Weak shortwave energy embedded in the deep west-northwesterly flow pattern has kicked off another round of convection across our area, with stronger storms currently crossing the Alapaha River to the west of Homerville in interior southeast GA. Widely scattered showers were moving eastward across the rest of our area, with breaks in the multi-layered cloud cover allowing temperatures at 19Z to reach the mid to upper 80s outside of rain-cooled locations. Dewpoints were generally in the lower 70s.

Moist and unstable west-northwesterly flow will advect weak shortwave energy into our region this afternoon, resulting in an increasing coverage of convection across most of our area. Deep tropical moisture and a slightly enhanced low level westerly jet of 25-35 knots at 850 millibars (around 5,000 feet) should cause a few storms to pulse and become strong, especially for locations near the remnant frontal boundary near and north of the I-10 corridor, and also where mesoscale boundaries collide randomly. Storms that pulse and become strong later this afternoon and evening will be capable of producing very heavy downpours, frequent lighting strikes, and downburst winds of 40-50 mph. Convection should mostly move offshore before midnight, with some potential for predawn showers and thunderstorms to develop near the Altamaha River in southeast GA as "backdoor" frontal boundary sinks into the Deep South overnight. Lows will generally fall to the 70-75 degree range overnight as a warm and humid air mass prevails across our area.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Main Highlights This Period:

- Wet, Stormy Weather Continues.

- Daily Localized Flooding Risk.

The lingering frontal boundary will continue to hang around the Florida/Georgia state border Sunday and Monday, bringing waves of showers across the area. High PWATs Sunday over 2.0" will keep the localized flooding threat ongoing over most of the area. The Weather Prediction Center is currently maintaining a 'Marginal' risk of excessive rainfall on Sunday, with southeast Georgia likely seeing higher rainfall accumulation. Westerly steering flow Sunday will keep the Atlantic sea breeze from pushing far inland, increasing thunderstorm chances near I-95 later in the day.

Flow begins to shift to northwesterly on Monday, bringing in slightly drier air (PWATs near 1.5-1.75") over inland southeast Georgia, lowering precipitation chances there to about 30-50%. Elsewhere, high PoPs continue with best thunderstorm chances in the afternoons and evenings both days near I-95 and north central FL.

Heavy cloud cover and an early start to rain Sunday will keep high temperatures below normal, only a few locations in north central Florida reaching 90 degrees. Monday will be a little bit warmer, in the mid to upper 80s to near 90. Overnight lows will be mild, in the lower to mid 70s for northeast Florida and the southeast Georgia coast.

LONG TERM /TUESDAY THROUGH SATURDAY/

Main Highlights This Period:

- Warmer with Less Storm Coverage Tuesday.

- Cooler, breezy & drier with inland storm Wednesday-Friday.

West/northwest flow will continue to bring lower (30-50%) rain chances inland, with higher chances (~60%) closer to I-95 and the Atlantic coast on Tuesday afternoon and evening. Wednesday onward, it looks to be drier and 'cooler' after a front pushes through the area Tuesday night and stalls over south central Florida. On Wednesday afternoon, areas south of the state border will see isolated to scattered convection as the front makes it's way southward. Thursday, isolated showers and storms remain possible primarily over portions of northeast Florida as drier air stays over southeast Georgia. Onshore winds develop Wednesday through Friday, keeping pleasant temperatures in the lower to mid 80s, and mild overnight low temperatures near the coast. Towards Friday into the weekend, that front may begin to lift back northward, but there remains a lot of uncertainty at this time.

AVIATION /18Z SATURDAY THROUGH 18Z SUNDAY/

Convection will otherwise increase in coverage and intensity this afternoon and evening. TEMPO groups for brief wind gusts up to 30 knots and IFR conditions during heavier downpours are included at the GNV terminal through around 22Z and through around 00Z/01Z at the northeast FL terminals. Confidence was only high enough to indicate MVFR conditions during heavier downpours at SSI at this time. A brief period of VFR conditions is forecast after 02Z, with IFR conditions then expected at VQQ after 06Z. MVFR ceilings are likely to develop at the regional terminals towards 13Z Sunday, with showers and possibly thunderstorms impacting the GNV terminal before 18Z. Confidence in timing and intensity of this potential activity was too low to currently indicate in the TAFs for the time period after sunrise on Sunday at this time. Outside of thunderstorm activity, westerly surface winds will remain sustained around 10 knots through around 23Z, followed by diminishing speeds this evening. Westerly surface winds should then increase to the 5-10 knot range after 13Z Sunday.

MARINE

A stationary frontal boundary situated over the Georgia waters this afternoon will dissipate tonight. A disturbance aloft will likely trigger another round of showers and thunderstorms across our local waters later this afternoon and evening, with a few stronger storms possible. Another frontal boundary will push into the southeastern states on Sunday morning as high pressure builds southward from the Great Lakes and Mid-Atlantic states. Additional rounds of showers and thunderstorms are forecast from Sunday through Tuesday evening as this front stalls over our area before a stronger cold front pushes southward across our local waters on Tuesday night. Northeasterly winds will surge in the wake of this frontal passage on Tuesday night as high pressure building over the Ohio and Tennessee Valleys wedges down the southeastern seaboard, creating Small Craft Advisory conditions from late Tuesday night through at least Wednesday night throughout our local waters. Breezy onshore winds and elevated seas are expected through Thursday night as high pressure gradually weakens over the southeastern states.

Rip Currents: A low to locally moderate risk today with surf of likely to be below 2 ft with buoys showing 1.5 ft seas. There is a lingering wind-sea swells of about 9 seconds. The risk may begin to rise back up to moderate to locally high Sunday afternoon into Monday due to onshore flow and increased surf.

FIRE WEATHER

A generally wet and stormy weekend expected as a frontal zone lingers over the area and interacts with daily sea breezes. Sunday, the lingering front will drop slightly further south, and a weak surface low develops along the boundary, bringing more rounds of widespread shower and thunderstorm activity into Sunday night. Patches of poor dispersions are expected on Sunday near the meandering frontal zone where winds will be weaker. Exactly where this boundary stalls will make a difference in expected wind direction, as far interior GA are expected to see more northeasterly winds Sunday, whereas further south towards the Ocala National Forest, west to southwesterly flow is expected.

Looking ahead, numerous to widespread showers and t'storms are likely to continue Monday before another front and drier air moves in mid week and lowers rain chances.

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 recently falls. Erratic winds will occur from thunderstorm activity, as well as the possibility of localized minor flooding from torrential rainfall.

PRELIMINARY POINT TEMPS/POPS

AMG 70 82 68 85 / 50 90 50 40 SSI 74 84 74 86 / 40 80 70 70 JAX 72 87 72 89 / 50 90 60 60 SGJ 74 87 73 89 / 50 80 40 70 GNV 73 89 72 89 / 20 60 30 70 OCF 73 88 74 88 / 30 60 40 60

JAX WATCHES/WARNINGS/ADVISORIES

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