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

- Flood Watch for Locations West of I-75 Through Monday Evening. Rainfall amounts of 1 to 3 inches, with locally higher amounts of 4 to 6

- Numerous TStorms through Early This Week. Strong Storm Potential Each Afternoon and Evening. Daily Rounds of Heavy Downpours May Cause Localized Flooding

NEAR TERM /THROUGH TONIGHT/

Main Highlights through Tonight:

- Rounds of Showers and Thunderstorms, Isolated Strong/Severe Storms Today

- Locally Heavy rainfall and flooding Possible, mainly west of the I- 75 corridor (Flood Watch)

A stalled frontal boundary will remain over GA just to the NW of the area today as high pressure over the Atlantic builds westward toward the SE US coast. This will maintain the SSW flow and anomalously high moisture (PWATs 2.2-2.4 in) supporting multiple rounds of heavy showers with embedded thunderstorms moving through NE FL and SE GA early this morning into evening. Locally heavy rainfall will remain the primary concern, with repeated rounds of convection capable of producing localized flooding, especially near and west of the I-75 corridor where around 2-5 inches of rain fell over this past weekend. A Flood Watch remains in effect today for counties along and west of I-75 where an additional 1-3 inches of rain could fall. Along with a flood risk, isolated strong to severe storms will be possible late this morning into afternoon capable of producing damaging wind gusts of 40 to 60 mph. Activity over the NE Gulf is currently moving northeastward into the I-75 corridor early this morning and will likely increase in coverage after sunrise into early afternoon as it overspreads across inland NE FL and SE GA. Hi res guidance continues to struggle with the timing of the "waves" of precip but a lull in activity may be possible in the late afternoon into early evening. Another round of showers will likely move into the I-75 corridor early Tuesday morning. Outside of storms, breezy SW winds will range from from 10 to 15 mph, with gusts up to 20 to 25 mph. Highs today will be below normal due to mostly cloudy skies and increased convection, only reaching the mid to upper 80s to around 90 closer to the coast. Lows will be in the lower 70s inland and the mid 70s along the coast.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/

Main Highlights This Period:

- Daily chances for isolated strong to severe thunderstorms, with wind gusts and heavy rainfall the greatest hazards

The region will be between a high pressure ridge to the south, and a weakening frontal zone to the north this period. Average to a little above average precipitation chances this period. Convection will initiate due to a combination of diurnal heating, and sea breeze interactions, and will mainly occur during the afternoon and evening hours.

Temperatures will be near to a little below normal this period.

LONG TERM /THURSDAY THROUGH SUNDAY/

Main Highlights This Period:

- Daily chances for isolated strong to severe thunderstorms, with wind gusts and heavy rainfall the greatest hazards

A high pressure ridge will build from the northeast this period. An inverted trough is expected to develop in the ridge over the local area. As the troughing strengthens, precipitation chances will increase through the week. With the high to the northeast, an onshore flow is expected this period, which will allow the east coast sea breeze to push well inland during the afternoons. With the sea breeze moving well inland, the beaches and I95 corridor will have the lowest chance for storms this period.

Temperatures will trend near to a little below normal this period.

AVIATION /06Z MONDAY THROUGH 06Z TUESDAY/

Showers will move in from the Gulf and spread to GNV early this morning and then into the Duval sites by 09Z. Periods of MVFR/IFR ceilings and visibilities will be possible with showers this morning. Rounds of showers with embedded thunderstorms then overspread the TAF sites mainly between 11Z - 18Z. Confidence is low on exact timing of showers and storms so have prevailing SHRA and VCTS with TEMPO/PROB30s to cover heavier storms. Southerly winds of 5-10 kts this morning quickly increase to south-southwesterly at 10- 15 kts with gusts around 20 kts. Showers begin to wane after 23Z.

MARINE

A cool front over northern Georgia will stall through mid-week. Small Craft Advisory conditions continue through early morning as a prevailing southwesterly offshore wind flow persists into mid-week. Rounds of mainly afternoon and evening showers and thunderstorms are expected to continue through Tuesday, with a few strong storms possible each afternoon and evening. The frontal boundary dissipates by Thursday as Atlantic high pressure builds westward back into the region with a shift to a more easterly flow.

Rip Currents: Prevailing offshore winds through Tuesday will likely yield a low to low-end moderate risk at area beaches.

FIRE WEATHER

Main Highlights This Period:

- Daily thunderstorm chances, with isolated strong to severe storms

Deep tropical moisture combined with persistent southwesterly flow will support numerous to widespread showers and thunderstorms today, with scattered to numerous thunderstorms continuing on Tuesday. Outside of convection, southwesterly winds of 10 to 15 mph with gusts of 20 to 25 mph are expected across northeast Florida, while lighter winds prevail across southeast Georgia. Dispersion values will generally range from fair to good today as increased transport winds offset lower mixing heights associated with extensive cloud cover and precipitation. Good dispersions prevail on Tuesday as mixing improves.

Fog Potential: Significant fog development is not anticipated through Tuesday morning due to persistent cloud cover, elevated low level moisture, and continued boundary layer mixing. Fire weather operations should anticipate sudden and erratic wind shifts, strong outflow winds, and dangerous cloud to ground lightning in and near thunderstorms.

PRELIMINARY POINT TEMPS/POPS

AMG 88 72 91 72 / 70 20 40 20 SSI 88 75 90 77 / 60 20 50 30 JAX 87 73 92 73 / 90 10 60 10 SGJ 88 74 91 75 / 60 20 70 10 GNV 85 72 91 71 / 90 30 50 0 OCF 86 72 89 72 / 100 50 50 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...Flood Watch through this evening for FLZ021-035-236-340-522. GA...None. MARINE...Small Craft Advisory until 6 AM EDT early this morning for AMZ450-452. Small Craft Advisory until 11 AM EDT this morning for AMZ470- 472.