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Hurricane Helene, Sep 23–28, 2024

1 of 2 · The storm's data
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Hurricane Helene, Sep 23–28, 2024

Hurricane Helene, Sep 23–28, 2024

Chapter 2 · First impacts

The first filing names Helene.

OneWater Marine files the first 8-K naming Helene.

04:00UTC · Thu, Sep 26, 2024 · 12:00 AM EDT

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Replay of past events. For current weather and warnings, see weather.gov. Links are rule-based facts. About and credits

Replay · AL092024

Helene: the story

Sep 23, 15:00 UTC – Sep 28, 18:00 UTC · 35 NHC advisories. Radar, warnings, storm reports, ground stops and SEC filings, in order, with 1,058 links that show their evidence.

  • 1,961 NWS warnings
  • 2,324 storm reports
  • 30 FAA airport programs
  • 134 8-Ks naming Helene
  • 1,058 rule-based links
  • 1,371,453 customers out at the peak, in South Carolina
  • 739 radar frames, 10 min apart

Approach

Sep 23–25

  1. The replay opens on the first NHC advisory.Replay from here

First impacts

Sep 26

  1. First 8-K naming Helene.
    “OneWater Marine filed an 8-K on 2024-09-26 naming Hurricane Helene”
    Replay from hereWhy linked

Landfall

Sep 27

  1. Helene makes landfall about 10 n mi southwest of Perry, Florida as a category 4 hurricane (120 kt, 939 mb).Replay from hereNHC Tropical Cyclone Report: Hurricane HeleneNHC best track (HURDAT2)

Inland

Sep 27–28

  1. Peak outages: 1,371,453 customers out of power in South Carolina. The most in one county: Greenville County, SC, 270,023 out (share unknown) at 22:00 UTC.Replay from here

Aftermath

Sep 28–Nov 12

  1. The replay window ends: the storm has dissipated.Replay from here
  2. The aftermath: 133 8-Ks name Helene after the storm, the last on 2024-11-12.Replay from here

How we link records

RuleWhat it checksLinks
R4 solidA storm report inside a warning polygon while it was in effect892
R3 solidAn SEC 8-K that names the storm134
R2 dashedAn airport program inside a warning that had been in effect for over 60 min (context)22
R5 dashedAn airport program inside the storm's own tropical watch or warning5
R1c solidA weather airport program inside a convective warning or watch, within 60 min of issuance4
R1o dashedThe same, for other hazards such as floods1

Solid lines mark rules that passed an independent check; dashed lines are context. Links are rule-based facts: each shows two records that overlap in place and time. How we know

Where this storm's data comes from

Every layer, the provider behind it and the period it covers.

LayerProviderPeriodRecords
MRMS SeamlessHSRNOAA/NSSL via Iowa Environmental MesonetSep 23, 15:00 UTC – Sep 28, 18:00 UTC739
NWS storm-based warning polygonsNOAA National Weather Service via Iowa Environmental MesonetSep 23, 15:00 UTC – Sep 28, 18:00 UTC1,961
NWS Local Storm ReportsNOAA National Weather Service via Iowa Environmental MesonetSep 23, 15:00 UTC – Sep 28, 18:00 UTC2,324
NHC advisories and best trackNOAA National Hurricane CenterSep 23, 15:00 UTC – Sep 28, 18:00 UTC35
FAA airport programs (ground stops and ground delay programs)FAA Air Traffic Control System Command CenterSep 23, 15:00 UTC – Sep 28, 18:00 UTC30
SEC EDGAR 8-K filingsU.S. Securities and Exchange CommissionSep 23, 15:00 UTC – Sep 28, 18:00 UTC134
ORNL EAGLE-IOak Ridge National LaboratorySep 23, 15:00 UTC – Sep 28, 18:00 UTC995
  • Radar: NOAA/NSSL MRMS SeamlessHSR, via the Iowa Environmental Mesonet (IEM), Iowa State University
  • Warnings: NOAA/NWS, storm-based polygons via the Iowa Environmental Mesonet
  • Storm reports: NOAA/NWS Local Storm Reports via the Iowa Environmental Mesonet
  • Advisories and best track: NOAA/National Hurricane Center
  • Airport programs: FAA Air Traffic Control System Command Center
  • Filings: U.S. Securities and Exchange Commission EDGAR
  • Power outages: Oak Ridge National Laboratory, EAGLE-I (CC BY 4.0)
  • County boundaries: U.S. Census Bureau