PREVIOUS DISCUSSION
Issued at 400 PM EDT Fri Jul 26 2024

Key Messages:

- Moistening trend this weekend and especially early next week should bring some needed rain to coastal sections.
- Heat indices reaching up to 103-106 daily.

Thru Tonight...A more well defined east coast sea breeze will continue to push inland into early evening, aided by outflow from showers and storms that spark along the boundary. Late morning Cape sounding shows some of that low level moisture has entrained some of the drier air in the mid levels and that has allowed dewpoints to fall into the upper 60s and lower 70s. Convective initiation occurred earlier this afternoon across the far north where deeper moisture resides. Expect an increase in storm coverage across the interior as boundary collisions occur. Slow and erratic cell motions will produce heavy rain with a quick 1-2 inches in some areas creating temporary flooding esp in urban areas and where recent heavy rains have occurred. Lightning strikes will be the primary threat. Once again the immediate coast has remained rain-free but outflow boundaries may push back to the Volusia and Brevard coasts and bring some shower activity with them after sunset. The good news for the coast is rain chances will be increasing over the next few days as deep moisture becomes more widespread and the steering flow (though weak)
increasingly favors the eastern peninsula.

Saturday-Tuesday (previous)...The mid-term forecast has become a little more unsure as a complicated upper-air pattern develops. A mid- level low developing over Texas gets swept up by a broad trough over the western US, while the mid-level trough over the eastern seaboard develops into mid-level low of its own as it pushes offshore into the western Atlantic. The upstream low is absorbed into the broad trough Sunday, cutting off the low over the western Atlantic until it too is absorbed late Monday or so.
GFS and ECM have slightly different results of this evolution, with ECM building a trough over the eastern US that digs all the way down to Florida, possibly supporting some stronger storms, while the GFS tilts the trough out into the western Atlantic instead.

For Florida, a surface low developing in the western Atlantic in response to the trough and mid-level low aloft is still expected to pull higher moisture associated with a frontal boundary across the CONUS down into Florida and further increase rain chances. If anything, there's now better agreement the drier air north of the boundary will stay offshore, keeping rain chances high. The question is how soon and how much the Atlantic high can build back, depending on where the mid-level trough ends up. As long as the high stays suppressed offshore, a loose pressure gradient will remain in place with little to no steering flow, which looks to be the scenario through Tuesday at this juncture. Thus, slow and erratic storm motion combined with the high rain chances will continue to pose a threat for localized minor flooding.

Once again no significant changes to forecast temperatures. While the humidity will certainly be back, the increasing rain chances and cloud cover will subtly lower afternoon highs a few degrees from the L-M90s Saturday to the U80s-L90s Tuesday. Heat indices follow a similar trend, peaking up to 107 Saturday, and 102 Tuesday.

Wednesday-Friday (previous)...The Atlantic high looks to build back to Florida by Wednesday or Thursday, reestablishing southerly to southeasterly flow depending where the ridge axis lands. Deep tropical moisture is transported across Florida in this flow, keeping daily rain chances at least 50-60 pct (continue to cap at 60 pct due to the time scale). Temperatures creep back up to the L-M90s, bringing heat indices back up towards 106.

AVIATION
(18Z TAFs)
Issued at 140 PM EDT Fri Jul 26 2024

VFR outside of convection. VCTS and TSRA TEMPOs are in place across the interior this afternoon where the greatest coverage of convection is forecast. Dry along the coast from MLB southward while VCTS/VCSH is mentioned at DAB/TIX. South winds become east with the sea breeze passage. However, the wind direction at LEE was a bit more tricky to pinpoint and could become largely variable due to multiple boundaries developing in vicinity of the terminal. Winds should generally remain 12 kts or less, but locally higher gusts will be possible along the Treasure Coast.
VCTS/VCSH could linger into the late evening across much of the interior, generally diminishing around 03Z. Light and variable winds overnight.

MARINE
Issued at 400 PM EDT Fri Jul 26 2024

Winds and seas favorable for boating, but shower and storm chances increase the next couple days, with high coverage expected Sunday through much of next week. A weakening Atlantic high will loosen the pressure gradient across the local waters, causing light southerly winds to become increasing variable, especially by Sunday and Monday, with the daily sea breeze shifting winds southeasterly to easterly at around 10 kts in the afternoon and evening. Seas 1-3 ft.

PRELIMINARY POINT TEMPS/POPS
DAB 75 93 75 91 / 20 60 30 60 MCO 77 95 76 93 / 50 70 20 70 MLB 76 93 76 91 / 20 40 20 60 VRB 74 93 75 91 / 20 30 10 60 LEE 76 94 76 92 / 50 70 30 80 SFB 77 95 76 92 / 40 70 30 70 ORL 77 95 77 93 / 50 70 20 70 FPR 74 93 74 91 / 10 30 10 60

MLB WATCHES/WARNINGS/ADVISORIES
FL...None.
AM...None.