Alert archive / Florida / Severe Thunderstorm Warnings in 2026
Severe Thunderstorm Warning 69, NWS Miami, FL
NWS Miami, FL issued this severe thunderstorm warning at Aug 21, 2026, 5:53 PM EDT for Palm Beach County, Florida. It was in force for 20 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 21, 2026, 5:53 PM EDT (21:53 UTC)
- Expired
- Aug 21, 2026, 6:13 PM EDT
- In force
- 20 min
- Issued by
- NWS Miami, FL
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
County Palm Beach County, FL
The radar
The Miami radar (KAMX), 91 km from the middle of the area, began a volume at 21:56 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The nearest sounding before it
Miami, FL (KMFL), launched 12:00Z, 9.9 hours before the alert went out and 73 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 2174 J/kg
- Mixed-layer CIN
- -9 J/kg
- Mixed-layer LCL
- 813 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 3 m²/s²
- 0-3 km storm-relative helicity
- -33 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
366 WUUS52 KMFL 212153 SVRMFL FLC099-212230- /O.NEW.KMFL.SV.W.0069.260821T2153Z-260821T2230Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Miami FL 553 PM EDT Fri Aug 21 2026 The National Weather Service in Miami has issued a * Severe Thunderstorm Warning for... Southwestern Palm Beach County in southeastern Florida... * Until 630 PM EDT. * At 553 PM EDT, a severe thunderstorm was located near Holey Land Wildlife Refuge, or 21 miles south of South Bay, moving north at 10 mph. HAZARD...60 mph wind gusts and penny size hail. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. * Locations impacted include... Holey Land Wildlife Refuge. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 2634 8053 2634 8076 2652 8074 2651 8046 TIME...MOT...LOC 2153Z 196DEG 7KT 2638 8064 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...0.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ NMP
1 follow-up statement
862 WWUS52 KMFL 212213 SVSMFL Severe Weather Statement National Weather Service Miami FL 613 PM EDT Fri Aug 21 2026 FLC099-212223- /O.CAN.KMFL.SV.W.0069.000000T0000Z-260821T2230Z/ Palm Beach FL- 613 PM EDT Fri Aug 21 2026 ...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN PALM BEACH COUNTY IS CANCELLED... The storm which prompted the warning has weakened below severe limits, and no longer poses an immediate threat to life or property. Therefore, the warning has been cancelled. LAT...LON 2634 8053 2634 8076 2652 8074 2651 8046 TIME...MOT...LOC 2212Z 196DEG 7KT 2642 8063 $$ NMP
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Miami, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 21, 3:37 PM EDT, 2 hours 16 minutes earlier. Its key messages:
- Updated at 335 PM EDT Fri Aug 21 2026
- Heat index values peak between 105-110 degrees today with a Heat Advisory in effect only for Miami-Dade and Broward counties.
- Scattered thunderstorms expected after midday and into the evening. A couple of stronger storms are possible that could produce near-severe winds.
Area forecast discussion, Aug 21, 3:37 PM EDT, 2 hours 16 minutes before
Area Forecast Discussion National Weather Service Miami FL 337 PM EDT Fri Aug 21 2026 ...New UPDATE... .KEY MESSAGES... Updated at 335 PM EDT Fri Aug 21 2026 - Heat index values peak between 105-110 degrees today with a Heat Advisory in effect only for Miami-Dade and Broward counties. - Scattered thunderstorms expected after midday and into the evening. A couple of stronger storms are possible that could produce near-severe winds. && .UPDATE... Issued at 335 PM EDT Fri Aug 21 2026 Water vapor satellite imagery shows a moister air mass continuing to overspread South Florida today, with recent ACARS sounding data showing PWATs around 1.9 inches. Isolated showers and thunderstorms have begun forming this afternoon along the Atlantic sea breeze, which has remained pinned close to the East Coast under persistent southwesterly flow. High-resolution model guidance continues to show increasing coverage of showers and thunderstorms across the eastern half of South Florida and around Lake Okeechobee through the rest of the afternoon into the early evening, with outflow boundaries potentially driving some activity into SW Florida around sunset. Primary threats include gusty winds, frequent lightning, and localized heavy rainfall, though an isolated severe storm cannot be completely ruled out. Convection is expected to gradually dissipate following the loss of daytime heating after sunset. Overnight lows tonight will range from the low 80s along the coasts to the mid 70s inland. && .SHORT TERM... (Today through Saturday) Issued at 116 AM EDT Fri Aug 21 2026 As the ridge in the Southwestern US continues to strengthen, increased jet dynamics will result in an amplified trough across most of the Eastern Seaboard through this weekend. The base of the trough is not anticipated to make it all the way to South Florida and the overall flow pattern will remain largely on the weaker side, but this enhanced troughing pattern is expected to keep a prevailing southerly/south-southwesterly flow pattern in place today and Saturday. Therefore, with abundant moisture advection continuing and elevated PWATs of 1.7-2.0" or even more in some areas, diurnal heating and sea breeze circulations each day will have the necessary ingredients to produce scattered to numerous showers and thunderstorms. With the primary south to south-southwest flow, this will favor interior and Southeast Florida for highest rain chances both today and on Saturday as showers and storms are expected to be the most widespread in these areas. Some activity will be observed across Southwest Florida as well, just not as widespread and thus rain chances are between 30-50% there versus 50-70% across Southeast Florida. Model soundings do highlight adequate SBCAPE of 3000-4000 J/kg as well as inverted-V signatures and steep low level lapse rates, so there will be an outside chance for an isolated severe storm or two via gusty winds. Otherwise, the primary hazards will be heavy rainfall that could lead to localized flooding in poor drainage areas, and sub-severe strong wind gusts. High temperatures the next couple days will remain in the low to mid 90s. The deeper moisture will also keep dew points in the mid to upper 70s each day, thus maximum heat index values are anticipated to remain elevated up to the 105-110F range. Isolated locations could experience heat index values a couple of degrees higher for a short period of time. With the expectation of some increased cloud cover today and perhaps slightly lower dew points, it has been decided to only issue a Heat Advisory for Miami-Dade and Broward counties from 11AM - 6PM today. HREF probabilities currently indicate a 10% or less chance for heat indices to reach 108F or higher. Depending on how conditions are trending through the morning, a short-fused expansion of the advisory will be possible but is not imminent. && .LONG TERM... (Saturday night through Thursday) Issued at 116 AM EDT Fri Aug 21 2026 As the trough draped across the Eastern Seaboard starts to erode early next week, the local wind regime will start to shift back to what we typically see in the summer time here in South Florida with low level flow being dominated by the Atlantic sea breeze. This will cause diurnal convection to start focusing back over both the interior and Southwest Florida rather than Southeast Florida like has been observed recently. Starting Monday, the highest rain chances (60-80%) will begin to focus across Southwest Florida and this will last through the end of the long term period. Latest guidance shows some slightly drier air (PWATs falling back below 1.8-2.0") this weekend, which could result in some slightly lower dew points that end the current streak of consecutive days with Heat Advisories. There is also potential for another Saharan Air Layer (SAL) to impact the area late in the weekend and early next week, but guidance highlights this SAL breaking up upon it's arrival and thus it's influence on a return to hot conditions should be less than the previous round. High temperatures are projected to remain in the low to mid 90s each day with overnight lows ranging from the low 70s across the interior and lake regions to the upper 70s and low 80s along the coastal metros. && .AVIATION... (18Z TAFS) Issued at 127 PM EDT Fri Aug 21 2026 SHRA/TSRA will increase in areal coverage throughout the day with the potential for sub-MVFR cigs/vis at some terminals in tandem with erratic wind shifts. Onshore winds increase at all terminals this afternoon, then return to light and variable after sunset. TEMPOs and short-fused amendments may be needed with future TAF updates. && .MARINE... Issued at 116 AM EDT Fri Aug 21 2026 Gentle west-southwest winds are expected across the Gulf waters today with southerly winds continuing across the Atlantic. The Atlantic winds will eventually become more southeasterly over the weekend. Seas will remain at 1-2 feet or less each day across all local waters. Scattered showers and thunderstorms are possible late each day and in the late night hours which may result in locally hazardous winds and seas. && .PRELIMINARY POINT TEMPS/POPS... Miami 80 94 79 93 / 10 30 20 60 West Kendall 78 94 77 92 / 10 40 20 70 Opa-Locka 79 94 79 93 / 10 40 10 60 Homestead 79 93 79 92 / 10 30 20 60 Fort Lauderdale 80 93 80 92 / 10 30 10 50 N Ft Lauderdale 80 93 80 93 / 10 30 10 50 Pembroke Pines 80 93 80 93 / 10 40 10 50 West Palm Beach 79 94 78 94 / 10 40 10 50 Boca Raton 79 92 79 92 / 10 30 10 50 Naples 79 91 79 91 / 10 20 10 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...Heat Advisory until 6 PM EDT this evening for FLZ071>074-172>174. AM...None. GM...None. && SHORT TERM...Redman LONG TERM....Redman AVIATION...DPB
In the hours before
Special weather statement, Aug 21, 5:12 PM EDT, 41 minutes before
Special Weather Statement
National Weather Service Miami FL
512 PM EDT Fri Aug 21 2026
FLZ063-212145-
Glades FL-
512 PM EDT Fri Aug 21 2026
...A strong thunderstorm will impact portions of northeastern Glades
County through 545 PM EDT...
At 511 PM EDT, National Weather Service meteorologists were tracking
a strong thunderstorm 7 miles northeast of Brighton Seminole
Reservation, or 7 miles west of Buckhead Ridge, moving north at 5
mph.
HAZARD...Wind gusts of 50 to 55 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Buckhead Ridge.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
These winds can down small tree limbs and branches, and blow around
unsecured small objects. Seek shelter in a safe building until the
storm passes.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 2720 8094 2719 8091 2718 8091 2717 8090
2717 8088 2715 8087 2713 8089 2712 8091
2710 8091 2710 8093 2709 8093 2709 8095
2708 8095 2711 8111 2721 8111 2721 8094
TIME...MOT...LOC 2111Z 194DEG 5KT 2717 8100
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...55 MPH
NMPThe office that day
Everything else NWS Miami, FL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 1:15 AM EDT | Heat Advisory | MFL | Broward, Miami-Dade | 17 hr |
| Aug 21, 7:19 AM EDT | Special Marine Warning | MFL | 41 min | |
| Aug 21, 9:02 AM EDT | Special Marine Warning | MFL | 28 min | |
| Aug 21, 4:45 PM EDT | Special Marine Warning | MFL | 30 min | |
| Aug 21, 5:12 PM EDT | Special Weather Statement | MFL | Okeechobee | 33 min |
| Aug 21, 5:15 PM EDT | Special Marine Warning | MFL | 30 min | |
| Aug 21, 5:25 PM EDT | Special Marine Warning | MFL | 20 min | |
| Aug 21, 6:25 PM EDT | Severe Thunderstorm Warning | MFL | Palm Beach | 22 min |
Nearby
Severe Thunderstorm Warnings in Florida, 2026Every severe thunderstorm warning in 2026
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.