The first strong cold front of fall moved through South Florida during the day on October 24th. Widespread showers and storms developed in the moist and unstable atmosphere ahead of this front, with boundary interactions producing a brief tornado over western Broward county.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MFL wrote it up.
The first strong cold front of fall moved through South Florida during the day on October 24th. Widespread showers and storms developed in the moist and unstable atmosphere ahead of this front, with boundary interactions producing a brief tornado over western Broward county.
The local office's own words before the first event, 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 the first event at Oct 24, 12:56 PM EST, 1 hour 19 minutes earlier.
Area Forecast Discussion National Weather Service Miami FL 156 PM EDT Tue Oct 24 2017 .AVIATION... Boundary collision will continue to enhance scattered showers and thunderstorms along the east coast terminals this afternoon. Expect lower vis with brief gusty winds as thunderstorm activity moves over the terminals. Frontal passage will move across the area enhancing more convection over the sites this afternoon. Winds will shift more northerly this evening into Wednesday. && .PREV DISCUSSION... /issued 1106 AM EDT Tue Oct 24 2017/ UPDATE... Cold front remains on track which will move through South Florida late tonight/early Wednesday morning, with a round of showers and thunderstorms expected to increase into the afternoon hours. Most of the early morning showers concentrated over the west coast will transition to the east coast metro areas as the morning progresses. Main forecast remains on track with current guidance with most of the activity gradually increasing into the afternoon hours. PREV DISCUSSION... /issued 748 AM EDT Tue Oct 24 2017/ AVIATION... Southerly flow will prevail over most of the Tafs sites today with slightly more sw towards APF as scattered shra are starting to develop. VCSH increasing after 15Z along the east coast with any a chance of a few thunderstorms until 00Z. VCSH will continue over APF 12Z and 15Z, then SHRA with VCTS until 00Z. The vis and ceilings will be VFR early this morning for most of the east coast, but should fall briefly down into MVFR conditions with the scattered SHRA activity near the area. PREV DISCUSSION... /issued 415 AM EDT Tue Oct 24 2017/ Showers and a Few Thunderstorms Today and Tonight... First Cold Front of the Season Moves Through Late Tonight... DISCUSSION... Short term (Today through Thursday): large and deep longwave trough over the eastern half of North America will be the driving force behind a cold front which will move through South Florida late tonight/early Wednesday morning, bringing the first shot of cooler and drier air of the season to our region. Before that happens, however, plenty of deep moisture will remain in place as the cold front currently across North Florida slowly moves down the peninsula today. Areas of showers and embedded thunderstorms will affect South Florida through tonight, with one pre-frontal round of precipitation this morning affecting primarily Gulf coast/SW Florida as well as coastal sections of SE Florida, then transitioning to the main area of showers and thunderstorms with the actual front this afternoon and tonight, aided by diurnal heating and sea breeze convergence. The front will move rather slowly today as the main piece of energy rotating around the deep eastern North American trough will not push into the Southeast U.S. until late tonight. This delay in the arrival of the mid/upper trough and associated dynamics/forcing, along with modest forecast CAPE values in the 1500-1800 j/kg range this afternoon during peak heating, should result in thunderstorms ahead of the front to be mainly below strong levels. Some gusty winds to 30-40 mph may accompany the most vigorous convection, with the main threat being locally heavy rainfall and flooding as the band of moisture moves slowly through the area ahead of the front. By the time the upper dynamics/forcing arrive, the front will be pushing through the area with cooler low level air overspreading the area by daybreak Wednesday. A few strong thunderstorms could set up over the Atlantic waters early Wednesday right ahead of the front, but should not affect land areas before the frontal passage. At this point we can say with reasonably high confidence that the frontal passage will essentially end the wet season, with the last day being today. Skies will be slow to clear behind the front on Wednesday even as cooler and drier air rushes in, as initial push will be shallow with the 850 mb and 700 mb troughs lagging behind. This sets up an overrunning pattern with light precipitation lingering for 4-8 hours after the frontal passage. Due to the clouds and cold air advection (haven't used that term in a discussion in quite a while), temperatures will likely remain steady or even fall a few degrees during the first part of the day and not recover until afternoon (maybe even late afternoon SE areas). Therefore, high temperatures will likely be several degrees cooler than MOS as it typically does not handle cold air advection/overrunning patterns in South Florida too well from a temperature perspective. Wednesday will feel quite a bit cooler for South Floridians after months of heat and high humidity. Highs will probably end up in the 70s all areas, but not after much of the day struggling to reach 70 degrees. Coolest period will be Wednesday night/Thursday morning as skies clear and north winds continue to filter down cool air. Most areas away from the immediate coasts will dip into the 50s, with upper 40s in the normally colder areas west of Lake Okeechobee and interior Collier County. Immediate east coast and urban cores, particularly MIA and FLL, may stay in the 60-62F range. These temperatures would be the coolest in South Florida since April 8th. Thursday will be a mostly sunny and mild day with highs in the upper 70s. Even though winds will become NE during the day, moisture recovery will be slow and humidity levels will remain low. Long term (Friday through Monday): Temperatures moderate on Friday as winds become E, but still mostly below late October norms for lows with readings mainly in the 50s and 60s, except near 70 along the east coast. A few showers return to the forecast, but Friday will be the last mostly dry day before deep tropical moisture surges back into South Florida Friday night and Saturday from the western Caribbean in association with an area of low pressure which as of this time has a 50% chance of tropical cyclone formation through 5 days. This northward transport of deep moisture will be aided by another deep and strong mid/upper level trough over the eastern U.S. which will send another cold front into the Gulf of Mexico and approach Florida late this upcoming weekend. Models have struggled somewhat over the past couple of days with respect to the evolution and timing of the northward movement of the western Caribbean low, but appear to be converging towards a general solution of an elongated south/north trough across the Straits of Florida, eastern Gulf of Mexico and Florida peninsula on Saturday, then shifting east of the area on Sunday as the main low in the vicinity of Cuba and the western Bahamas gets driven east by the deep mid-latitude trough and frontal system. This system bears watch as it remains to our south this week and gradually moves north, but right now the main potential impact to South Florida as this early stage appears to be heavy rainfall and possible flooding Saturday and early Sunday. The next cold front then is progged by the majority of the available guidance to sweep through on Sunday, which would usher in another shot of cool air and below normal temperatures to South Florida to end the weekend and begin next week. MARINE... Decent marine conditions outside of showers and thunderstorms most of today, but deteriorating tonight as the cold front moves through the local waters and thunderstorms affect mainly the Atlantic waters late tonight. Seas are expected to build to 8 feet over the outer Gulf of Mexico waters on Wednesday behind the front, and to 7 feet in the Gulf Stream off the east coast. Winds will gust to 25 to 30 knots on Wednesday. These conditions will likely necessitate a Small Craft Advisory with this afternoon's forecast package. Wind and seas will gradually subside on Thursday and Friday but still remain at moderate levels. Conditions again deteriorate this weekend as showers/thunderstorms spread across all waters Saturday and early Sunday, along with increasing wind and seas by Sunday. FIRE WEATHER... The season's first surge of cooler and drier air will drop relative humidity values into the 35 to 40 percent range western areas on Wednesday and area-wide on Thursday. For the time being it looks like marginal red flag conditions at best, without considering the ERC values which in all likelihood will remain below critical levels. Humidity levels recover Friday through Sunday. PREV DISCUSSION... /issued 127 AM EDT Tue Oct 24 2017/ AVIATION... The winds will be south/southeast around 5 to 10 knots today over most of the taf sites. The only exception to this is at KAPF taf site where the winds will become southwest this afternoon. The weather should remain dry over the east coast taf sties through early this morning, before VCSH conditions between 12Z and 17Z. After 17Z today, the weather will be dominated by showers with any a chance of a few thunderstorms until 00Z. Therefore, VCSH between 12Z and 17Z, then SHRA with VCTS until 00Z. KAPF taf site will have VCSH until 12Z then SHRA with VCTS until 17Z, then VCSH for the afternoon hours. The vis and ceilings will in the VFR conditions early this morning, but should fall down into MVFR conditions after 12Z today due to the showers and thunderstorms. AVIATION...54/BNB && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 70 76 55 76 / 70 40 0 0 Fort Lauderdale 70 74 59 78 / 70 40 10 0 Miami 69 74 60 78 / 70 40 10 0 Naples 63 75 56 76 / 30 0 0 0 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && AVIATION...67/MT
Hazardous Weather Outlook for South Florida National Weather Service Miami FL 1027 AM EDT Tue Oct 24 2017 AMZ610-630-650-651-670-671-FLZ063-066>075-168-172>174-GMZ656-657-676- 250230- Lake Okeechobee-Biscayne Bay- Coastal waters from Jupiter Inlet to Deerfield Beach FL out 20 NM- Coastal waters from Deerfield Beach to Ocean Reef FL out 20 NM- Waters from Jupiter Inlet to Deerfield Beach FL from 20 to 60 NM- Waters from Deerfield Beach to Ocean Reef FL from 20 to 60 NM excluding the territorial waters of Bahamas-Glades-Hendry- Inland Palm Beach-Metro Palm Beach-Coastal Collier-Inland Collier- Inland Broward-Metro Broward-Inland Miami-Dade-Metro Miami-Dade- Mainland Monroe-Coastal Palm Beach-Coastal Broward-Coastal Miami- Dade-Far South Miami-Dade- Coastal waters from Chokoloskee to Bonita Beach FL out 20 NM- Coastal waters from East Cape Sable to Chokoloskee FL out 20 NM- Waters from Chokoloskee to Bonita Beach FL from 20 to 60 NM- 1027 AM EDT Tue Oct 24 2017 ...SCATTERED STORMS ARE POSSIBLE ACROSS SOUTH FLORIDA... ...MINOR FLOODING POSSIBLE ACROSS SOUTH FLORIDA... ...MARINE CONDITIONS DETERIORATE LATE TONIGHT INTO WEDNESDAY... This hazardous weather outlook is for South Florida. .DAY ONE...TODAY AND TONIGHT Thunderstorms: Scattered thunderstorms are possible today into this evening over South Florida. The primary impacts from the thunderstorms will be lighting strikes and heavy rainfall. Flooding: Minor flooding is possible in low lying and poorly drained areas from the heavy rainfall associated with the thunderstorms. Rip currents: There is a slight risk of rip currents along the east coast beaches of South Florida. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY Isolated to scattered thunderstorms will be possible Wednesday morning over the Atlantic waters, and then again over all of South Florida on Saturday. The primary impacts will be lightning strikes and heavy rainfall. Marine conditions will deteriorate late tonight into Wednesday over both the Atlantic and Gulf of Mexico waters, with seas up to 8 feet in the Gulf waters and 7 feet over the Gulf Stream. Hazardous seas will continue into Thursday. The risk of rip currents at the Atlantic beaches will increase by end of the week into early this weekend before decreasing early next week. The threat of rip currents will increase along the west coast beaches of South Florida late this weekend into early next week. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. For more information...visit the National Weather Service in Miami website at www.weather.gov/miami.
The Miami radar (KAMX), 59 km away, was scanning. The volume nearest the first event began at 19:14 UTC.
1 tornado. Local standard time, as filed.
Multiple photos and videos received via social media show a brief tornado touchdown just south of I-75 and west of US-27 west of the city of Weston. The tornado remained over an open field before lifting. Time estimated by radar.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2017Every state in 2017This day in weather historyThe tornado archive for Florida, 2017Warnings in Florida, October 2017
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 724171.