An upper-level trough was across the eastern US with unsettled SW steering flow over the local forecast area. An old outflow boundary from prior convection moved across NE FL through the afternoon, which combined with sea breeze forcing and diurnal instability triggered a few strong to severe storms.
Every event with a place to put it. Tap one for its entry below.
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 JAX wrote it up.
An upper-level trough was across the eastern US with unsettled SW steering flow over the local forecast area. An old outflow boundary from prior convection moved across NE FL through the afternoon, which combined with sea breeze forcing and diurnal instability triggered a few strong to severe storms. Stronger dynamics (effective shear of 20-25 kts) and seasonably cool 500 mb temps (-10 degC) were across SE GA, but drier low-level air limited low-level instability and limited storm growth.
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 Jacksonville, FL wrote its last area forecast discussion before the first event at May 17, 10:41 AM EST, 2 hours 39 minutes earlier.
Area Forecast Discussion National Weather Service Jacksonville FL 1141 AM EDT Wed May 17 2023 ...New AVIATION... .UPDATE... Issued at 907 AM EDT Wed May 17 2023 Forecast remains on track. Slightly delayed the onset of Pops by a couple of hours due to the later start of convection developing along the Gulf sea breeze this morning. && .NEAR TERM... (Today and Tonight) Issued at 424 AM EDT Wed May 17 2023 Mean layer flow through 500 mb is west-southwest over the region with a broad trough from the eastern U.S. through the lower MS Valley. Sfc cold front is noted from the Carolinas back to the west- southwest over AL and MS. Mean layer wind speeds are near 15-20 kt. We are starting off with higher PWATS than yesterday with values of near 1.5 to 1.7 inches per GOES imagery, which is approximately 30 percent higher than normal. Some instability available already over the area given the higher moisture levels but cap is noted in the mesoanalysis. During the day, the front and mid level troughing expected to shift southeastward, increasing general synoptic scale ascent in the area. Based on model guidance, should see an early start to convection today, first over the Suwannee Valley area into parts of southeast GA. Then, activity will grow in coverage and intensity as it progresses eastward. Have scattered to numerous showers and storms for today, with the best chances over north half of the area. Some model discrepancies though handling convective development so it's possible parts of southeast GA may not see a lot of activity through 4-5 pm. By late aftn and more so the evening, better forcing arrives aloft from the northwest to provide more of an uptick in convection, mainly for areas from I-10 northward. Sufficient mid level winds and instability available for an isolated strong to briefly severe storm this aftn and evening with gusty wind and heavy rainfall the main threats. Highs today will be similar to yesterday. Tonight, with the front pressing down into GA, numerous showers and storms expected to be ongoing in the evening over southeast GA, with periods of heavy rainfall anticipated. More scattered activity expected for northeast FL. Anticipate just a very gradual decrease in rain chances overnight given the high moisture content (PWAT ~1.8 inches) and disturbances aloft. Continued threat for locally heavy rainfall/localized flooding with the high moisture in place and decent outflow winds at 250-300 mb. For min temps, lows will be in the upper 60s to around 70. && .SHORT TERM... (Thursday through Friday night) Issued at 424 AM EDT Wed May 17 2023 Shortwave troughing will pivot across the Deep South on Thursday and Thursday night, moving off the Carolina coast by Friday afternoon. Meanwhile, a sprawling surface ridge will migrate eastward off the Mid-Atlantic coast by Thursday afternoon, driving a "backdoor" cold front down the southeastern seaboard, with this boundary then pushing through northeast and north central FL on Friday afternoon and evening. Deep moisture will pool just to the south of the approaching front across our area, resulting in convection initially blossoming across southeast GA during the mid to late afternoon hours. Outflow boundaries propagating southward from this activity will then collide with the inland moving Gulf and Atlantic sea breeze boundaries across northeast and north central FL towards sunset, resulting in convection expanding across the I-10 and down the I-95 corridors during the late afternoon and early evening hours. Widespread heavy downpours will be possible, increasing concerns for localized flooding, especially across inland southeast GA, where soils should be saturated after today's expected downpours. Urban flooding may also become an issue elsewhere, as a few rounds of storms and training convection become possible. Breezy northeasterly winds will develop during the afternoon hours at coastal locations as our local pressure gradient tightens from north to south. Highs on Thursday should remain in the upper 70s to lower 80s for locations north of I-10, while upper 80s prevail further to the south across north central FL, where convective coverage is not expected to increase until the late afternoon hours. The shortwave trough crossing the southern Appalachians on Thursday evening should result in weak cyclogenesis along the front off the GA coast, and this front should then push southward across the FL/GA border during the overnight hours. Widespread evening convection along the I-95 corridor should push offshore towards midnight. Cloudy skies and a northeasterly breeze will keep lows in the mid 60s to upper for inland locations, ranging to around 70 at coastal locations, where winds will shift to north- northwesterly in the wake of the front and developing low pressure offshore. A weak pressure pattern will prevail locally on Friday as weak low pressure migrates north-northeastward along the Gulf Stream waters off the Carolina coast and the aforementioned frontal boundary stalls and weakens near the Interstate 4 corridor in central FL. Northwesterly flow aloft will attempt to advect a slightly drier air mass over inland southeast GA, but just enough low level moisture will remain in place for scattered afternoon and early evening showers and thunderstorms to develop, mainly along the inland moving Atlantic sea breeze boundary across northeast and north central FL. Coverage will likely become numerous for locations closer to the stalled boundary, or for areas south of Gainesville, by late afternoon, while the drier air mass attempting to advect into southeast GA limits convective coverage to isolated or widely scattered. Highs on Friday will range from the upper 70s to lower 80s at coastal locations to the upper 80s to near 90 for north central FL. Widely scattered convection could continue just past sunset on Friday for north central FL near the weakening frontal boundary, with dry weather otherwise expected overnight. Fog formation may be possible towards sunrise on Saturday as winds decouple and skies clear, with lows only falling to the mid and upper 60s inland, with lower 70s forecast at coastal locations. && .LONG TERM... (Saturday through Tuesday) Issued at 424 AM EDT Wed May 17 2023 A potent shortwave trough will pivot across the Great Lakes region from Friday through Saturday night, driving a cold front into the southeastern states on Saturday afternoon and evening. Moisture levels will recover enough for widely scattered late afternoon and evening convection to develop along colliding mesoscale boundaries on late on Saturday afternoon, with activity potentially lingering well into the evening hours across southeast GA as the cold front pushes through the Deep South. Plenty of morning and early afternoon sunshine will boost highs to the upper 80s and lower 90s inland, while an afternoon sea breeze keeps coastal locations generally in the mid 80s. Lows on Saturday night should remain in the 65-70 degree range ahead of the approaching front, except lower 70s at coastal locations. Troughing aloft will approach the U.S. eastern seaboard on Sunday, pushing the aforementioned cold front through southeast GA during the afternoon hours, before support aloft for this boundary wanes on Sunday night and Monday, resulting in the front decelerating and then stalling across northeast FL early next week. Scattered convection is expected along the front on Sunday afternoon and evening, with highs again climbing to the upper 80s to around 90 at inland locations before convective coverage increases, while highs generally remain in the mid 80s at coastal locations. Flow aloft will then become zonal on Sunday night and Monday, with a much drier air mass likely remaining just north of the Altamaha/Ocmulgee Rivers, while shortwave energy embedded in the zonal flow begins to migrate eastward from the northern Gulf coast towards our region as early as Monday afternoon. There will likely be at least a brief break in convective coverage on Sunday night, with lows falling to the mid and upper 60s inland, ranging to the lower 70s at the coast. Shortwave troughing migrating across our area on Monday is expected to decelerate and become cutoff over the Deep South as a blocking pattern aloft potentially develops over the eastern U.S. Meanwhile, strong surface high pressure building over the eastern Great Lakes and New England in the wake of the Sunday cold frontal passage may become anchored along the eastern seaboard towards the early to middle portions of next week, resulting in coastal trough development over our near shore Atlantic waters. This complex scenario could result in an extended period of breezy onshore winds, with plenty of deep moisture remaining locked in place over our area as the front stalls near the I-10 corridor. Waves of heavy downpours could materialize beginning on Monday night and Tuesday, especially along the I-95 corridor. We will monitor the long term forecast trends for consistency heading into next week, but there is the potential for a much wetter pattern evolving as onshore flow strengthens and taps into deep moisture pooling along a stalled frontal boundary during a good portion of next week. Increased clouds and breezy onshore winds would keep highs in the low to mid 80s at most locations, with lows remaining in the 70s along the I-95 corridor, with 60s further inland. && .AVIATION... (18Z TAFS) Issued at 1141 AM EDT Wed May 17 2023 West-southwest flow around 10 kts prevails today with the Gulf coast sea breeze shifting inland leading to showers and thunderstorms already moving into GNV and JAX metro sites before noon. Lingering showers and potential storms in the evening, but lower confidence on including anything more than VCSH. Light winds expected near sunrise for NE FL sites. && .MARINE... Issued at 424 AM EDT Wed May 17 2023 Generally light winds, below 15 kt, expected through Thursday ahead of a cold front moving into the forecast area, with seas of up to 2-4 ft, and dominant wave periods of 7-8 seconds. Sea heights may drop a bit tonight and Thursday. Main wx concerns through Thursday will be offshore moving showers and t-storms with gusty winds possible. The cold front is expected to move southward into the waters on Thursday with winds shifting to the east and then northeast through the day. A sfc low forms offshore Thursday night and Friday, which will bring winds further around to the north- northeast up to near 15 kt with building seas. Forecast winds and seas are not as strong as prior forecasts but still may touch on small craft exercise caution levels Thursday night and Friday. On Saturday, east-northeast flow generally under 15 kt and still some elevated seas for small boaters expected. By Sunday, another cold front will move in from the northwest but at this time winds and seas look to be below SCA criteria. Rip Currents: Wind waves of 2-2.5 ft and small east swells will favor a low-end moderate risk of rip currents again today, with slightly lower risk indicated for southeast GA waters. Lower surf heights may result in low risk for Thursday. && .FIRE WEATHER... Issued at 424 AM EDT Wed May 17 2023 Isolated strong to severe thunderstorms will be possible across southeast GA from the late afternoon through the evening hours today. Otherwise, breezy westerly surface and transport winds will develop shortly after sunrise, creating good daytime dispersion values, with marginally high values possible across portions of north central FL this afternoon. Numerous afternoon and evening showers and thunderstorms are forecast on Thursday, with heavy downpours expected across much of our area. Lighter northeasterly surface and transport winds will result in poor daytime dispersion values across southeast GA and the Suwannee Valley, while westerly transport winds result in fair to good dispersion values for locations south of I-10. Surface and transport winds will then shift to northerly on Friday, with good dispersion values expected across northeast and north central FL, while fair values are forecast for southeast GA. && .PRELIMINARY POINT TEMPS/POPS... AMG 87 67 79 65 / 80 80 80 50 SSI 88 70 78 69 / 70 40 80 70 JAX 90 68 83 67 / 50 40 90 70 SGJ 88 70 85 70 / 50 10 80 80 GNV 88 68 87 66 / 40 10 70 80 OCF 88 68 88 68 / 30 10 50 70 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. &&
Special Weather Statement
National Weather Service Jacksonville FL
206 PM EDT Wed May 17 2023
FLZ125-133-325-171830-
Coastal St. Johns FL-South Central Duval FL-Coastal Duval FL-
206 PM EDT Wed May 17 2023
...A strong thunderstorm will impact portions of northern St. Johns
and southeastern Duval Counties through 230 PM EDT...
At 206 PM EDT, Doppler radar was tracking a strong thunderstorm over
Baymeadows, or over Unf, moving east at 20 mph.
HAZARD...Winds around 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Unf, Ponte Vedra Beach, Jacksonville Beach, Atlantic Beach, Neptune
Beach, Baymeadows, Mayport, Craig Field and San Pablo.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3019 8165 3030 8167 3043 8139 3022 8135
TIME...MOT...LOC 1806Z 250DEG 16KT 3027 8155
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
KBSpecial Weather Statement
National Weather Service Jacksonville FL
209 PM EDT Wed May 17 2023
FLZ125-171845-
Coastal Duval FL-
209 PM EDT Wed May 17 2023
...A strong thunderstorm will impact portions of east central Duval
County through 245 PM EDT...
At 208 PM EDT, Doppler radar was tracking a strong thunderstorm over
Fort Caroline, or 8 miles northeast of Arlington, moving east at 15
mph.
HAZARD...Winds around 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Little Talbot Island, Fort Caroline and Talbot Island.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3037 8152 3042 8155 3052 8142 3043 8138
TIME...MOT...LOC 1808Z 247DEG 14KT 3041 8148
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
KBThe Jacksonville radar (KJAX), 27 km away, was scanning. The volume nearest the first event began at 18:22 UTC.
4 thunderstorm wind, 1 hail. Local standard time, as filed.
Severe thunderstorm winds damaged utility equipment on Little Talbot Island. The time of damage was based on radar imagery.
A restaurant along the St. Johns River had an electric sign blown over and damaged by thunderstorm winds. The time of damage was based on radar.
Two trees were blown down across 2 lanes of Interstate 75 at mile marker 467. The time of damage was based on radar imagery.
A tree was blown down across Dyal Road and US Highway 1 NW of Callahan. The time of damage was based on radar data.
Nickel size hail was reported in Flagler Beach along S 23rd Street.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2023Every state in 2023This day in weather historyWarnings in Florida, May 2023
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: 1098172, 1098173, 1098175, 1098174, 1098170.