textproduct: Miami - South Florida

KEY MESSAGES

Updated at 805 AM EDT Sun May 3 2026

- Showers and storms chances will peak during the afternoon hours of today. Heavy rainfall, lightning, and gusty winds will be the main hazards possible with any thunderstorms.

- Chances of showers and thunderstorm will linger into early next week as the frontal boundary stalls out just to the south of the region.

- Above average temperatures return to the region during the middle portion of the upcoming work week.

SHORT TERM

(Today through Monday) Issued at 212 AM EDT Sun May 3 2026

Ample sunshine, gusty southerly winds, and record sizzling temperatures were experienced during the first half of the weekend across South Florida. A very different day is forecast to play out weather-wise across our area today. Ample cloud cover, deep atmospheric moisture, and light northerly to northeasterly winds behind a frontal boundary will support the potential of scattered to numerous showers and thunderstorms this afternoon as well as much cooler temperatures. While not a complete washout by any means, cloud cover and potential PM rounds of showers and storms could put a damper (pun intended) on outdoor plans. Let's get into forecast specifics for today, beginning with current conditions across the region.

06z Mesoanalysis combined with ACARS data from SoFlo airports depict light and variable winds with nocturnal stabilization (convective inhibition and a shallow surface inversion) now across the peninsula. This will keep things quiet across South Florida proper for the next several hours before the nocturnal inversion and convective inhibition erode. Robust convective activity for the time being will be confined to the Gulf waters and to our south over the Florida Keys. Surface observations upstream across Central Florida reveal the continued prorogation of the frontal boundary southward as a notable temperature and dewpoint drop is being observed. Mesoscale models remain in agreement that the frontal boundary will slide into the upper Florida Keys by daybreak with surface winds veering out of a northerly direction from north to south across our area. Interestingly enough (and what will be a common theme later on in this AFD), even though the frontal boundary will slide southward into the Florida Keys by daybreak, forecasted precipitable water values over South Florida during this time frame will be nearing historical daily maximum values for the date as moisture pools along and just north of the frontal boundary.

A robust mid-level shortwave arrives across South Florida late today into tonight providing an boost of synoptic energy in tandem with the continuation of an amplified southern stream jet-streak (enhanced upper level divergence) over the entirety of the peninsula. Although South Florida will reside firmly on the "cool" side of the surface boundary, residual instability (CAPE of 1000- 2000 J/kg) & high precipitable water values (Above the 90th percentile and close to the daily max), low level convergence, and upper level divergence could result in scattered diurnal convection firing up across portions of the east coast metro area (especially across Miami-Dade and Broward counties which will remain closer in spatial extent to the boundary) once nocturnal convective inhibition erodes. Given that we are indeed on the cool side of the boundary, some uncertainty remains on the exact placement of convection given that the best instability is along and south of where the boundary stalls. While any developing diurnal convection will be fast moving given brisk flow aloft, the saturated profile supports the potential of efficient rainfall rates if and where convection is able to materialize.

Mesoscale models still remain split on how today will play out with a few model solutions depicting heavier thunderstorm activity setting up along the immediate east coast while other models depict any rainfall maxima occurring just offshore over the Gulfstream waters. Widespread most likely (50% chance of exceedance) rainfall totals of 0.5 to 1.5" are forecast for most of the region today with a reasonable worst case (1 in 10 chance) solution of a few isolated pockets of 2-3+" inches of rainfall. Given how susceptible our east coast metro urban areas are to heavy rainfall in short periods of time, a low-end threat remains for isolated localized flooding today. The Weather Prediction Center continues to maintain the marginal risk (level 1 of 4) for excessive rainfall across the eastern half of South Florida today. Hazards with any thunderstorm development over land this afternoon include: frequent lightning, gusty winds, and heavy rainfall. With 500mb temperatures still in the -9C to -10C range aloft, small sub-severe hail could not be ruled in the tallest convective cores. Cloud cover as well as shower and thunderstorm activity will keep temperatures significantly cooler than yesterday with forecasted high temperatures this afternoon ranging from the mid to upper 80s across extreme southern Florida to the low 80s (perhaps a smattering of upper 70s across far northeastern SoFlo) across the remainder of the region.

Deterministic and ensemble model guidance as well as recent 00z mesoscale models still depict the development of a surface signal to the mid-level vorticity in the form of developing low pressure over the Gulf Stream waters that will quickly advect northeastward during the early morning hours of Monday. Cyclonic flow on the back side of the low pressure system will result in a wrapping in of drier air into the northern half of region and a precipitable water gradient from northwest to southeast by Monday afternoon. Scattered showers and a few storms will remain possible across most of the region on Monday as forecast precipitable water values remain between the daily mean and 75th percentile across southern locales. Meager instability and the post frontal airmass will keep any threat of more robust convection in check. The slight enhancement of a pressure gradient behind the departure of the surface low will enhance breezy northeasterly winds which will also result in a temperature gradient from northeast to southwest across the region. Temperatures will range from the low 80s across coastal Palm Beach County to temperatures in the upper 80s across coastal southwestern Florida.

LONG TERM

(Monday night through Saturday) Issued at 212 AM EDT Sun May 3 2026

With the frontal boundary forecast to effectively be stationary to our south over the Caribbean Sea and Florida Straits on Tuesday, higher precipitable water values will remain with us even on the north side of the boundary. This will once again support the development of a few showers and thunderstorms during the afternoon hours on Tuesday where ascent is maximized (mesoscale boundaries). An active synoptic pattern will continue as the amplification of a longwave trough over the northeastern Unite States which will result in a continuation of the southern jet-stream in the vicinity of South Florida as 500mb flow begins to veer more northwesterly as the trough axis lifts out to the northeast and away from the southeastern United States. At the surface, the axis of surface ridging in place across the western Atlantic waters will begin to lift off to the northeast. Anticyclonic flow around this feature will veer winds to more of an easterly component as surface winds gradually lessen in strength. A temperature gradient will once again develop during the afternoon hours, now more oriented from east to west as forecast high temperatures on Tuesday afternoon will range from the low to mid 90s along the east coast of South Florida to temperatures in the upper 80s to near 90 across the western half of the peninsula.

A pattern change aloft is in the cards beginning late on Tuesday into Wednesday as a stout and anomalous mid-level ridge slides eastward across the Gulf. 500mb temperatures could approach the daily maximum for the date with values potentially above -4C to -5C at 500mb. LREF GEFS Climatology has 500mb temperatures aloft of South Florida in the 97-99th percentile Tuesday night into Thursday. A ridge of this strength aloft will have a strong subsidence inversion which will suppress and limit rain chances outside of a few isolated showers along afternoon boundary collisions. If you are a fan of the miami heat (no pun intended this time), it'll be another scorching period with forecast high temperatures on Wednesday through Friday in the low to mid 90s across much of the region. Mesoscale sea-breezes will veer winds onshore along both coasts during the afternoon hours bringing some welcome relief to coastal locales.

The mid-level ridge begins to flatten on Thursday night into Friday as a long-wave trough transits across the central United States as a combined polar and southern jet-stream amplifies in intensity once again. 500mb temperatures are forecast to begin to gradually cool as 500mb flow becomes more zonal across our region as South Florida is forecast to be situated in between the troughing to the north and the mid-level ridge to our south. A developing surface low ahead of the trough across the northeastern United States will provide enough synoptic influence to drag an attendant frontal boundary southward across the southeastern United States on Thursday and southward across the Florida Peninsula on Friday. Model solutions at this temporal range remain split on the evolution of this next surface frontal boundary. Both the ECENS and GEFS ensemble guidance now depict the frontal boundary stalling out and becoming frontolytic in nature just to the north of our region Friday into the upcoming weekend as zonal flow continues aloft. While the boundary may not make it to South Florida, a plume of the deeper atmospheric moisture (forecasted 1.5 to 1.7 inches precipitable water values) envelope associated with the boundary is forecast to arrive across South Florida each afternoon from Friday into the upcoming weekend. With light background winds across the region, south of the stalled boundary across Central Florida during this period, diurnal sea- breeze circulations will kick in each afternoon focusing shower and thunderstorm chances along the inland propagating boundaries and outflow collisions. Forecast high temperatures for next weekend currently reside in mid to upper 80s across coastal locales with widespread 90s inland.

AVIATION

(12Z TAFS) Issued at 805 AM EDT Sun May 3 2026

Morning round of storms is moving through with sub-VFR impacts to the terminals. Some improvement is expected with a lull in convection until the next round in the afternoon. Gusty and erratic variable wind shifts could also occur if SHRA/TSRA directly impacts a terminal. L/V winds expected after sunset with decreasing SHRA/TSRA over land.

MARINE

Issued at 212 AM EDT Sun May 3 2026

Surface winds will veer to a northerly than northeasterly direction across the local waters today behind the arrival of a frontal boundary across the region. Intermittent periods of small craft exercise caution (SCEC) conditions may develop across the northern Atlantic water zones as a pressure gradient enhances and wanes in the wake of the boundary passage to the south of the region. Seas across the local Atlantic waters will generally range between 3 to 5 feet range on Sunday increasing to 4 to 6 feet on Monday as wave heights build in response to the northerly wind component up against the northward moving Gulfstream current. Seas will remain in the 2 to 3 feet range across the local Gulf waters today before lessening to the 1 to 2 feet range on Monday. With rain chances remaining elevated today into Tuesday, any shower or thunderstorm activity could result in locally hazardous winds and waves. Continued northeasterly winds behind the frontal boundary on Monday could result in wave heights remaining slightly elevated in the Gulfstream before winds veer to more of an easterly component on Tuesday and wave heights gradually lessen. Light winds are forecast during the mid week period of the work week as winds across the nearshore waters veer in the direction of the coast each afternoon.

PRELIMINARY POINT TEMPS/POPS

Miami 84 72 82 73 / 80 70 60 30 West Kendall 86 69 85 69 / 80 70 60 30 Opa-Locka 85 71 84 72 / 80 70 60 30 Homestead 86 71 84 73 / 80 70 60 40 Fort Lauderdale 82 72 80 72 / 80 70 50 40 N Ft Lauderdale 81 72 80 72 / 80 70 50 30 Pembroke Pines 86 72 85 74 / 80 70 60 30 West Palm Beach 79 71 80 71 / 80 60 40 30 Boca Raton 80 71 80 72 / 80 70 50 30 Naples 82 69 86 69 / 70 50 30 20

MFL WATCHES/WARNINGS/ADVISORIES

FL...None. AM...None. GM...None.