Area Forecast Discussion

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

- Moderate Rip Current Risk this Weekend at Area Beaches.

- Unseasonably Dry with a Gradual Warming Trend through Monday.

- Patchy Fog Possible Inland Early on Monday and Tuesday Mornings.

- Isolated Afternoon & Evening Thunderstorms Possible Across Inland Southeast GA on Tuesday.

- Gradually Increasing Chances for Afternoon & Evening Showers and Thunderstorms from Wednesday through Friday.

- Heat Index Values Climb to the 100-105 Degree Range by Late in the Upcoming Week.

NEAR TERM /THROUGH TONIGHT/

Main Highlights This Period:

- Drier Than Normal Conditions Continue - Moderate Rip Current Risk At Area Beaches

Drier than normal early summer conditions continue today as surface high pressure continues to slowly shift towards east of the region. As a result, flow direction will be more out of the southeast, which will limit rip current risk to the moderate range at area beaches with winds only around 10 mph at the coast. Gradual uptick in moisture will allow diurnal "fair weather" clouds to form once again late this morning and afternoon, with otherwise near zero chances for any rain. Ridging aloft will continue to build today, increasing high temperatures by a few degrees: Upper 80s to low 90s will be common, with the exception of the immediate coast which is expected to be closer to the mid 80s.

Tonight, some patchy fog and/or low clouds may form over some inland areas, but otherwise dry and a few degrees warmer than Friday Night on average with lows in the mid 60s to low 70s.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Main Highlights This Period:

- Unseasonably Dry Conditions Continue with Inland Temperatures Warming to the Low and Mid 90s.

- Moderate Rip Current Risk Continues at Area Beaches.

Deep-layered ridging will persist across our area, with this feature deflecting a potent shortwave trough currently over west Texas northeastward across the Plains states, the Upper Midwest, and western portions of the Great Lakes. The base of this trough will progress eastward across the lower Mississippi Valley on Monday and will enter the Deep South by Monday night, which will flatten ridging that will extend from the Gulf eastward across the FL peninsula. Weak surface high pressure centered off the southeastern seaboard will continue to extend its axis westward across our region, with a rather loose local pressure gradient allowing the Atlantic sea breeze to develop towards noon on Sunday and Monday at coastal locations, with an onshore breeze keeping highs generally in the upper 80s at area beaches. Highs at inland locations will soar to the low and mid 90s on both afternoons. Dewpoints will crash to the upper 50s and lower 60s for locations well inland on Sunday afternoon, keeping heat index values close to actual temperatures. Heat index values should reach the 95-100 degree range across northeast and north central FL on Monday afternoon as dewpoints generally remain in the 60s inland and around 70 at coastal locations. Lows will generally fall to the low

LONG TERM /TUESDAY THROUGH FRIDAY/

Main Highlights This Period:

- Gradually Increasing Chances for Showers and Thunderstorms from Wednesday through Friday.

- Summertime Humidity Returns, with Heat Index Values Climbing Above 100 Later in the Upcoming Week.

A weakening trough aloft progressing across the Deep South on Tuesday may encounter just enough moisture to spark isolated to widely scattered afternoon and early evening showers and thunderstorms across inland portions of southeast GA. Meanwhile, a "backdoor" cold front pushing down the southeastern seaboard will decelerate as troughing progresses offshore of New England, with another high pressure center building off the Mid-Atlantic coast tightening our local pressure gradient slightly. This evolution of the weather pattern will push the Atlantic sea breeze quickly inland on Tuesday afternoon, setting up a possible collision with the Gulf coast sea breeze west of the I-75 corridor towards sunset, where enough low level moisture may be in place for isolated showers and thunderstorms to briefly develop. Breezy onshore winds on Tuesday afternoon will keep coastal highs in the mid to upper 80s, with increasing cloud cover for locations north of Waycross in southeast GA also keeping highs in the mid to upper 80s. Highs elsewhere will generally reach the lower 90s.

High pressure will weaken by midweek as it shifts southward off the southeastern seaboard, with ridging aloft over the U.S. eastern seaboard setting up a return to the typically hot and humid weather pattern for our area. A looser local pressure gradient will allow both the Atlantic and Gulf coast sea breezes to develop and progress inland on Wednesday afternoon, with PWATs climbing to around 1.75 inches, or slightly above climatology for mid-June, allowing for at least widely scattered showers and thunderstorms developing by the late afternoon and evening hours, mainly at inland locations where mesoscale boundaries will collide. Highs will soar to the low and mid 90s at most inland locations, with coastal highs mostly in the upper 80s due to an early developing sea breeze. Dewpoints will still fall into the 60s during the afternoon hours at inland locations, keeping heat index values below 100. Lows on Tuesday night will generally fall to the low and mid 70s.

Deep-layered ridging will retrograde westward late this week, allowing troughing to develop over the central or eastern Gulf that may eventually become cutoff. Deep-layered flow will likely become southerly, which will further increase moisture levels across our area. Afternoon and evening showers and thunderstorms will become likely for north central FL on Thursday, with scattered coverage elsewhere, especially along mesoscale boundary collisions such as sea and river breezes. Model blends indicate numerous afternoon and evening showers and thunderstorms for inland portions of northeast and north central FL by Friday. With activity currently expected to take on a more diurnal flavor, summertime heat and humidity will expand across our region per long term model blends. Inland highs will climb to the mid 90s, with highs around 90 extending to area beaches. Increasing humidity levels will boost afternoon heat index values to the 100-105 degree range on Thursday and Friday afternoons, and lows will only fall to the mid 70s inland and the upper 70s for coastal locations.

AVIATION /12Z SATURDAY THROUGH 12Z SUNDAY/

VFR conditions are expected to prevail through the TAF period. East/southeast winds around 10 knots this afternoon and evening, especially for eastern Duval terminals and the coast.

MARINE

High pressure situated along the southeastern seaboard early this morning will shift eastward this afternoon, with this feature becoming centered near Bermuda by late tonight. A cold front will shift southward towards our area on Tuesday, with this boundary weakening as it moves southward across our local waters on Tuesday night. High pressure will briefly strengthen along the Mid-Atlantic coast in the wake of this frontal passage on Tuesday, with this feature then weakening as it shifts off the southeastern seaboard by midweek. Breezy onshore winds will develop each afternoon behind the inland moving sea breeze. Scattered showers and thunderstorms will be possible late during the upcoming week as moisture levels gradually increase from south to north.

Rip Currents: Rip current risk is moderate at all area beaches through this weekend.

FIRE WEATHER

- Unseasonably Dry Weather Expected Through Monday

An unseasonably dry air mass will remain in place across our area through Monday, limiting chances for rainfall. Isolated to widely scattered afternoon and evening showers and thunderstorms will be possible on Tuesday, mainly across inland portions of southeast Georgia. Otherwise, minimum relative humidity values will fall to around 30 percent at inland locations this weekend, with values only slowly recovering on Monday. Elevated mixing heights will continue at inland locations, with gradually decreasing east to southeasterly transport winds today yielding generally good daytime dispersion values inland, with fair values at coastal locations, where breezy onshore winds will develop early this afternoon following the passage of the Atlantic sea breeze boundary. Transport winds will weaken further on Sunday, creating generally fair daytime dispersion values, except good values for most of north central and portions of inland northeast Florida. A slight increase in easterly transport winds on Monday afternoon will yield good daytime dispersion values for inland locations south of Waycross, Georgia, with fair values continuing elsewhere.

FOG POTENTIAL AND OTHER REMARKS: Patchy fog formation will be possible at inland locations during the predawn and early morning hours on Monday and Tuesday.

PRELIMINARY POINT TEMPS/POPS

JAX WATCHES / WARNINGS / ADVISORIES

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