textproduct: Miami - South Florida

KEY MESSAGES

Updated at 741 AM EDT Mon May 4 2026

- Showers and storms remain possible through Tuesday as a frontal boundary remains in the vicinity of South Florida.

- Hazardous marine conditions and dangerous rip currents are forecast along and offshore of the Palm Beach coast today.

- Above average temperatures return to the region mid to late this week. Probabilities of heat-related impacts across urban areas during this time frame continue to increase.

SHORT TERM

(Today through Tuesday) Issued at 236 AM EDT Mon May 4 2026

06z mesoanalysis now shows the axis of a amplified shortwave now pushing offshore of the Florida Peninsula into the western Atlantic waters. This synoptic injection of energy aloft has enhanced upper level divergence over our region which has resulted in the onset of scattered to numerous shower and thunderstorm development across the local waters where surface instability remains high. Light east- north easterly surface winds along the Palm Beach and Broward coastline has also resulted in weak coastal convergence as scattered shower activity has developed along an instability gradient right along the east coast. This upper level divergence is also occurring over the stationary front that is now draped from SW to NE across the Florida Straits from just north of Cuba into the northwestern Bahamas early this morning. The right entrance region of the associated southern stream jet-streak has resulted in a maxima of low level convergence which should facilitate the development of a weak area of non-tropical low pressure over the next several hours, directly along the boundary in the vicinity of the northwestern Bahamas. As the mid-level shortwave continues to accelerate northeastward into the western Atlantic waters as the day progresses, this low level feature will accelerate to the northeast in tandem. Cyclonic surface wind flow on the back side of this feature will result in the wrapping in of drier continental air into the northern half of region and a precipitable water gradient from northwest to southeast by this afternoon. However even with this trend of lessening atmospheric moisture content, forecast precipitable water values are still forecast to remain between the daily mean and 90th percentile for today's date from north to south across the area. Various convection allowing models (CAMs) continue to depict varying levels of diurnal showers and storms this afternoon. Similar to yesterday, forecast widespread cloud cover on the north side of the boundary during the day time hours could serve as a limiting factor that could keep any convective activity spatially in check. If breaks in the cloud cover do occur, diurnal heating could spur greater instability and more shower and storm coverage. Regardless, meager overall 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 to gusty northeasterly winds which will also result in a diurnal temperature gradient from northeast to southwest across the region. Temperatures this afternoon will range from the low 80s across coastal Palm Beach County to temperatures in the mid to upper 80s across coastal southwestern Florida.

With the frontal boundary forecast to still be effectively stationary to our south over the Florida Straits on Tuesday, precipitable water values near the daily mean will remain with us to the north of the increasingly diffuse 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 next lobe of mid-level troughing slides offshore of the northeastern United States into the northwestern Atlantic. This 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 further off to the northeast. At the surface, the axis of surface ridging in place across the western Atlantic waters will also 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 80s along the east coast of South Florida to temperatures in the upper 80s to near 90 across the western half of the peninsula.

LONG TERM

(Tuesday night through Sunday) Issued at 236 AM EDT Mon May 4 2026

A pattern change aloft will set the stage for above average temperatures across the region beginning during the middle portion of the work week. The culprit? The arrival of a anomalously strong 500mb mid-level ridge that will gradually slide eastward across the Gulf beginning late on Tuesday into early Wednesday. 500mb temperatures could approach the daily maximum (warmest) values during this stretch with values potentially above -4C to -5C at 500mb. LREF GEFS Climatology has 500mb temperatures aloft of South Florida in the 97-99th percentile and at times near the daily max value late Tuesday night into Friday morning. A ridge of this strength aloft will also result in strong subsidence at the surface, which will hinder and suppress rain chances outside of low- capped cumulus afternoon cloud cover and a non-zero chance of a few isolated sprinkles along afternoon boundary collisions where ascent is maximized. 500mb flow will remain anticyclonic in nature around this feature as the ridge axis slowly propagates just to the south of our region late in the work week. At the same time, an envelope of drier precipitable water values will also push into the region during this time frame which will mix more dry air down the surface during the afternoon hours reinforcing the dry period.

Kinematics out of the way, let's hone more in on forecast details. The lack of convective activity and a shallow layer of cumulus clouds will do little to stifle high temperatures during this period. Beginning on Wednesday and persisting through at least Friday, perhaps even into the upcoming weekend, high temperatures across the region are forecast to reach the low to mid 90s with the exception of ocean cooled coastal areas which will max out in the mid to upper 80s. While the mixing down of drier air to the surface will keep apparent temperature and ambient temperature differences lower in separation compared to our standard summer heat, apparent temperatures values in the upper 90s to low 100s are still possible. NWS's Prototype Probabilistic HeatRisk depicts a medium (50%) to high (70%) probability of Major HeatRisk (Level 3 of 4) beginning on Thursday across the east coast metro and persisting through at least Saturday, potentially expanding into the Naples metro later in the week as well. While these probabilistic values may fluctuate as we remain several days out in time, Major HeatRisk can be impactful to anyone without adequate cooling/hydration as well as health system and industries. Be sure to keep up with the latest forecast updates over the next several days.

A long wave trough is forecast to propagate across the Great Lakes region at the end of the work week. 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 across the northern Gulf coast on Friday. Model solutions have come into better agreement in depicting the frontal boundary stalling out and becoming frontolytic in nature just to the north of our region Friday into the upcoming weekend as southwesterly 500mb flow continues aloft. It appears the stunted southward movement of the boundary may be caused by the fact that the ensemble and deterministic guidance has trended a little less progressive with the mid-level ridging over the past 24 hours now depicting a gradual displacement of the ridge axis southward next weekend.

While the boundary may not make it to South Florida, a plume of the deeper atmospheric moisture envelope associated with the boundary could arrive across South Florida Friday into the upcoming weekend. With light background winds across the region, south of the stalled boundary across Central/Northern Florida during this period, diurnal sea-breeze circulations could kick in each afternoon focusing shower and thunderstorm chances along the inland propagating boundaries and outflow collisions. Latest forecast has daily PM rain chances in the 20-40% range during this time frame. 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 741 AM EDT Mon May 4 2026

Shower activity has been waning throughout the morning, with ceilings lifting from north to south along the eastern side of the peninsula. One or two more hours of IFR cigs may be observed over Dade County, but cloud cover should continue to lift and break apart. Breeze northeasterly winds are expected throughout the day, before diminishing after sunset. Confidence is low on coverage for storms, but VCTS was included for most sites for this afternoon. Scattered storms will have the potential to produce some gusty and erratic winds, along with brief visibility impacts.

MARINE

Issued at 236 AM EDT Mon May 4 2026

Northeasterly winds will enhance across the region at daybreak, becoming breezy to gusty across all local waters as a pressure gradient briefly enhances. 00z HREF guidance depicts a high (70-90%) probability of reaching 20 knot sustained wind thresholds across the northern Atlantic waters today which also lines up well with ECMWF guidance. A Small Craft Advisory has been issued for the northern Atlantic waters from 8am this morning to 5pm this afternoon. Wave heights will reach the 4-6 feet range in the Atlantic waters today before lessening overnight into Tuesday. Wave heights will remain in the 1-2 feet range across the local Gulf waters before decreasing further in height on Tuesday as winds across the region veer easterly and lessen in strength.

BEACHES

Issued at 236 AM EDT Mon May 4 2026

Gusty onshore winds and the return of northeasterly swell will result in a high risk of rip currents at Palm Beach beaches through at least this evening with a moderate risk for Broward and Miami- Dade beaches as well today. An elevated risk of rip currents may linger at Palm Beach beaches on Tuesday before lessening northeasterly swell and surface winds reduce the threat of rip currents during the middle to late portion of the work week.

PRELIMINARY POINT TEMPS/POPS

Miami 83 73 85 73 / 60 30 40 10 West Kendall 85 70 87 70 / 60 30 40 10 Opa-Locka 84 73 86 74 / 60 30 40 10 Homestead 85 73 86 73 / 50 30 40 10 Fort Lauderdale 80 72 82 73 / 60 40 40 10 N Ft Lauderdale 80 72 82 73 / 60 30 40 10 Pembroke Pines 85 73 87 75 / 60 30 40 10 West Palm Beach 79 71 82 72 / 50 30 40 10 Boca Raton 80 72 82 73 / 60 30 40 10 Naples 85 70 87 71 / 30 20 20 0

MFL WATCHES/WARNINGS/ADVISORIES

FL...High Rip Current Risk through this evening for FLZ168.

AM...Small Craft Advisory until 8 PM EDT this evening for AMZ650-670.

GM...None.