Strong surface heating produced scattered thunderstorms across the Florida Peninsula during the afternoon and early evening hours. One of these storms caused downburst winds that did isolated damage to an apartment roof.
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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 TBW wrote it up.
Strong surface heating produced scattered thunderstorms across the Florida Peninsula during the afternoon and early evening hours. One of these storms caused downburst winds that did isolated damage to an apartment roof.
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 Tampa Bay, FL wrote its last area forecast discussion before the first event at May 20, 1:55 PM EST, 3 hours 30 minutes earlier.
Area Forecast Discussion National Weather Service Tampa Bay Ruskin FL 255 PM EDT Sat May 20 2017 .SHORT TERM... An elongated area of high pressure currently located off the Mid-Atlantic coast with mid-upper level ridging is providing easterly flow across SW Florida through the period. Similar to yesterday, this flow will keep the seabreeze from moving farther than a Brooksville-Punta Gorda line. Morning 12z RAOB came in a little drier than yesterday's with PW at 1.41 inches. However, PW have been increasing slightly through the day and with sufficient instability in place, thunderstorms are likely to fire up along the seabreeze late this afternoon into the evening. The main focus for convection will be along the I-75 corridor with storms slowly drifting west towards the coast. On Sunday, the ridge to our north begins to flatten out and will weaken our prevailing easterly flow... allowing for the seabreeze to penetrate farther inland. The greatest area of low-level convergence and moisture will located south which will keep the greatest chances for seabreeze thunderstorms seabreeze mainly south of Tampa. Additionally, the weakness in the ridge will allow a weak shortwave to move across north FL and this could provide additional forcing for more thunderstorms in Levy county. .LONG TERM... A mid/upper-level ridge over the region will be suppressed southward for the first few days of the coming week as a broad trough spreads over the central and eastern part of the country. At the surface, a rather weak cold front will try to move into northern Florida on Monday, but will stall to our north. The surface high pressure axis will stretch across the south-central part of the peninsula for both Monday and Tuesday afternoons, with a south to southwest flow in place. This will shift the best rain chances more toward the interior and eastward for both days. The forecast becomes a bit more interesting for the middle part of the week. The GFS shows a large closed low moving into the Great Lakes region Wednesday and Wednesday night, with surface low pressure quickly moving northeastward and dragging a cold front through the region. The ECMWF also shows these features, but generally shows them farther north. We will have to see how these features evolve over the next couple of days, but for now, this does look like our next good rain chance. Some drier air and hopefully slightly cooler weather will then move into the region to end the week. Temperatures will then quickly warm back up for the weekend. && .AVIATION... VFR conditions observed across the area this afternoon under partly cloudy skies. Expecting showers and thunderstorms to begin to develop over the next few hours. VCTS mentioned at all terminals in the 20-22Z time frame continuing into the early evening before ending around 02-03Z. As always, localized MVFR/IFR reductions will be possible in and around tstms. && .MARINE... High pressure north of the waters will result in east and southeast winds...but shifting to onshore near the coast in the afternoons... into early next week. Then the high pressure slowly moves south with winds veering to south then southwest through midweek...and increasing to near advisory speeds as a cold front approaches from the north. && .FIRE WEATHER... Atlantic high pressure across north Florida will provide east and southeast flow...except becoming onshore near the coast in the afternoons...through Monday. Relative humidity is expected to remain above critical levels through the period. && .Preliminary Point Temps/PoPs... TPA 74 90 74 87 / 60 10 30 40 FMY 72 91 72 90 / 20 40 40 40 GIF 72 92 72 91 / 10 40 30 60 SRQ 73 86 72 85 / 50 20 30 30 BKV 70 90 70 88 / 40 10 40 50 SPG 75 89 76 87 / 50 10 30 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && SHORT TERM/AVIATION/MARINE/FIRE WEATHER...11/McKaughan 42/Norman MID TERM/LONG TERM/DECISION SUPPORT...05/Carlisle
Hazardous Weather Outlook National Weather Service Tampa Bay Ruskin FL 505 AM EDT Sat May 20 2017 FLZ043-050-052-056-057-061-139-142-148-149-151-155-160-162-165- 239-242-248-249-251-255-260-262-265-GMZ830-836-850-853-856-870- 873-876-210000- Sumter-Pinellas-Polk-Hardee-Highlands-DeSoto-Coastal Levy- Coastal Citrus-Coastal Hernando-Coastal Pasco- Coastal Hillsborough-Coastal Manatee-Coastal Sarasota- Coastal Charlotte-Coastal Lee-Inland Levy-Inland Citrus- Inland Hernando-Inland Pasco-Inland Hillsborough-Inland Manatee- Inland Sarasota-Inland Charlotte-Inland Lee-Tampa Bay waters- Charlotte Harbor and Pine Island Sound- Coastal waters from Tarpon Springs to Suwannee River FL out 20 NM- Coastal waters from Englewood to Tarpon Springs FL out 20 NM- Coastal waters from Bonita Beach to Englewood FL out 20 NM- Waters from Tarpon Springs to Suwannee River FL out 20 to 60 NM- Waters from Englewood to Tarpon Springs FL out 20 to 60 NM- Waters from Bonita Beach to Englewood FL out 20 to 60 NM- 505 AM EDT Sat May 20 2017 This Hazardous Weather Outlook is for West Central And Southwest Florida. .DAY ONE...Today and Tonight. ...THUNDERSTORM IMPACT... Scattered thunderstorms are expected this afternoon and evening, especially over the coastal counties where the sea breeze collision will occur late in the day. Thunderstorms that develop will be capable of producing strong gusty winds, locally heavy rainfall, and frequent deadly lightning strikes. If lightning is observed or thunder is heard move indoors immediately. .DAYS TWO THROUGH SEVEN...Sunday through Friday. ...THUNDERSTORM IMPACT... Scattered thunderstorms are expected mainly during the afternoon and evening hours Sunday through Tuesday. The locations with the best chances of seeing rainfall will however shift each day as the weather pattern changes. For Sunday the best chances will be over inland areas near the Interstate 75 corridor and just east as the west coast sea breeze should move inland to this area. On Monday and Tuesday the flow will become more south to southwest taking the highest rain chances into the interior and eastern half of the Florida peninsula. Wednesday into Thursday a cold front is expected to move toward and through the region bringing scattered to numerous showers and thunderstorms to the entire area. On Friday this front will have stalled across south Florida with an isolated thunderstorm still possible south of the Interstate 4 corridor. Any thunderstorms that do develop during the upcoming week will be capable of producing strong gusty winds, locally heavy rainfall, and frequent deadly lightning strikes. ...MARINE IMPACTS... A breezy southwest flow will setup ahead of the cold front Tuesday night into Wednesday night shifting to west to northwest on Thursday. Wind speeds are expected to reach exercise caution, possibly small craft advisory criteria during this time. These winds will create hazardous boating conditions for small craft operators. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today. PRC
The Tampa radar (KTBW), 42 km away, was scanning. The volume nearest the first event began at 22:22 UTC.
1 thunderstorm wind. Local standard time, as filed.
State emergency management relayed a report of isolated damage to the gable of a two-story apartment building. The gable was ripped free causing part of the roof to collapse into the an apartment. No other damage was reported nearby.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2017Every state in 2017This day in weather historyWarnings in Florida, May 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: 689311.