Field Verification Record

TorCAST Against
Real Events

Timestamped TPI scores from the TorCAST archive, matched against NWS warning issuance times and confirmed severe weather reports. Every data point on this page is sourced and labeled.

228
Severe Events Scored
82%
Ceiling Hit Rate
18%
Bust Rate
±2.41
Mean TPI Error

Ceiling Hit Rate — of the cases where TorCAST showed elevated potential, the share where verified severe weather then occurred in that area and window. Higher is better.

Bust Rate — how often TorCAST showed elevated potential and no verified severe weather followed. Lower is better.

Mean TPI Error — how far the score usually missed by on the 0–10 scale: the average gap between the pre-event TorCAST score and the verified event severity.

Scored across TorCAST's lifetime record against official NWS warnings and SPC / IEM storm reports — tornado, hail, and wind. Each snapshot is matched to later reports by location and time window, and must pre-date the storm, so there is no hindsight. Delayed reports and damage surveys back-fill automatically, so figures move as the official record is completed.

As of — · updates automatically as new reports verify
Case Study 01 · Tornado · Iowa
Iowa Statewide
Tornado Warning Sequence
JUNE 10, 2026 · NWS Des Moines / Quad Cities / La Crosse
tornado TORNADO WARNINGS · STATEWIDE
Case
Iowa Statewide
Event
Tornado Warning Sequence
Peak TPI
6.5
First TorCAST heads-up
10:34 AM CDT
First warning
1:44 PM CDT
Lead time
3h 10m
Verification
NWS DMX / DVN / ARX tornado warnings + SPC & IEM LSR reports
3h 10m
Archive-only case — no operational post required.
The TorCAST warning-validation archive shows Iowa holding TPI 5.0+ across 200–300 grid points from 10:34 AM CDT with zero tornado warnings. No operational social media post is required to establish this record — the archive is the timestamped operational log. First tornado warnings appeared at 1:44 PM CDT. TPI peaked at 6.5 at 4:45 PM CDT during the active warning period. This event demonstrates that TorCAST's pre-warning signal is a continuous engine output, not dependent on whether a post was published.
TorCAST Timeline — June 10, 2026 (All times CDT / UTC · Iowa)
Time (CDT) Time (UTC) TPI (Max) Grid Points Tor-Warned Source Note
10:34 AM 15:34Z 5.1 239 0 Archive TPI 5.0+ across 239 Iowa grid points. No tornado warnings in the state.
11:28 AM 16:28Z 5.6 294 0 Archive Building to 5.6 across 294 pts — largest pre-warning coverage. No warnings.
12:13 PM 17:13Z 5.6 211 0 Archive TPI 5.6 sustained. No warnings. Atmosphere loading.
12:59 PM 17:59Z 5.7 202 0 Archive Final pre-warning archive read. TPI 5.7 — peak pre-warning signal. Still zero tornado warnings.
1:44 PM 18:44Z 6.1 352 26 Archive First tornado warnings in Iowa. 26 of 352 grid points under active tornado warnings. TPI jumps to 6.1.
2:44 PM 19:44Z 6.2 374 25 Archive Event continuing. TPI 6.2 across 374 Iowa grid points.
4:45 PM 21:45Z 6.5 360 40 Archive Peak TPI of 6.5 — 40 Iowa grid points under active tornado warnings.
5:45 PM 22:45Z 6.2 304 32 Archive Event winding down. TPI 6.2, 32 grid points still warned.
Data sources: All rows are from the TorCAST warning-validation archive for Iowa (lat 40.4–43.5°N, lon 89.1–96.6°W), indexed against NWS Des Moines (DMX), Quad Cities (DVN), and La Crosse (ARX) tornado warning polygons. No operational post exists for this event. The archive record stands independently — the engine was running and logging elevated TPI across Iowa for 3 hours 10 minutes before the first NWS tornado warnings were issued.
open_in_newSPC Storm Reports — June 10, 2026 open_in_newIEM LSR Archive — June 10 Tornado Reports open_in_newNWS Des Moines (DMX)
Case Study 02 · Tornado · Eastern Illinois
Marshall / Clark County, Illinois
Tornado Emergency
JUNE 11, 2026 · NWS Lincoln (LIN)
warning TORNADO EMERGENCY
Case
Marshall / Clark Co., IL
Event
Tornado Emergency
Peak TPI
6.5
First TorCAST heads-up
4:08 PM CDT
First warning
~5:15 PM CDT
Lead time
1h 7m
Verification
NWS Lincoln (LIN) warning records + SPC & IEM LSR reports
1h 7m
From TorCAST operational post to Tornado Emergency in Marshall, IL.
TorCAST posted elevated tornado potential for central Illinois at 4:08 PM CDT. A Tornado Emergency was subsequently issued for Marshall, Clark County, IL at approximately 5:15 PM CDT — one of the rarest NWS tornado products, reserved for confirmed tornadoes with imminent catastrophic impact on a populated area. The TorCAST archive shows eastern Illinois holding TPI 5.0–5.4 across this sub-region continuously from 9:15 AM CDT with zero tornado warnings in the area until the Tornado Emergency.
TorCAST Timeline — June 11, 2026 (All times CDT / UTC · Eastern IL / Clark County)
Time (CDT) Time (UTC) TPI (Max) Grid Points Tor-Warned Source Note
9:15 AM 14:15Z 5.4 13 0 Archive Eastern IL (Clark/Crawford/Coles) first elevated archive read of the afternoon cycle. No warnings.
11:01 AM 16:01Z 5.4 33 0 Archive TPI holding at 5.4 across 33 eastern IL grid points. No warnings.
12:02 PM 17:02Z 5.3 37 0 Archive Sustained elevated signal. No warnings.
2:46 PM 19:46Z 5.2 79 0 Archive Coverage expanding — 79 eastern IL points at TPI 5.0+. No warnings issued.
4:08 PM 21:08Z — — None Post TorCAST posts elevated tornado potential for central Illinois. Marshall / Clark County area flagged.
4:47 PM 21:47Z 5.4 25 0 Archive Last archive snapshot before Tornado Emergency. TPI 5.4 — 0 tor-warned in the sub-region.
~5:15 PM ~22:15Z — — TOR EMRG NWS Tornado Emergency issued for Marshall / Clark County, IL. Confirmed tornado. Rare NWS designation — catastrophic impact imminent.
5:47 PM 22:47Z 6.2 40 9 Archive TPI surging to 6.2 during the Tornado Emergency. 9 eastern IL grid points under active tornado warnings.
6:50 PM 23:50Z 6.5 46 14 Archive Peak archive TPI of 6.5. 14 of 46 grid points tornado-warned. Event continuing.
Data sources: Archive rows are from the TorCAST warning-validation log for eastern Illinois (lat 38.5–40.5°N, lon 86.5–88.5°W), indexed against NWS Lincoln (LIN) tornado warning polygons. Archive captures TPI across this sub-region continuously from the morning hours with 0 tor-warned until the Tornado Emergency window. Post 4:08 PM CDT entry is from TorCAST operational post timestamped in the record. NWS Tornado Emergency time (~5:15 PM CDT) is from NWS Lincoln warning records. The archive shows 8 hours of sustained TPI 5.0+ across eastern Illinois before the Tornado Emergency was issued.
open_in_newSPC Storm Reports — June 11, 2026 open_in_newIEM LSR Archive — June 11 Tornado Reports open_in_newNWS Lincoln, IL (LIN)
Case Study 03 · Tornado · Ohio / Western Pennsylvania
Ohio & Western Pennsylvania
Tornado Warning Corridor
JUNE 14, 2026 · NWS Cleveland / Pittsburgh / Wilmington
tornado MULTIPLE TORNADO WARNINGS
Case
Ohio / W. Pennsylvania
Event
Multiple Tornado Warnings
Peak TPI
6.3
First TorCAST heads-up
7:09 AM EDT
First warning
4:25 PM EDT
Lead time
5+ hrs
Verification
NWS CLE / PBZ / ILN tornado warnings + SPC & IEM LSR reports
5+ hrs
From first TorCAST read to first tornado warnings in the corridor.
TorCAST flagged organized tornado potential at 7:09 AM EDT across the Ohio–Pennsylvania corridor — hours before storms initiated. The TorCAST archive shows TPI building through the morning and afternoon with no warnings issued until 4:25 PM EDT. Multiple Tornado Warnings were subsequently issued for Jefferson County PA, Clearfield County PA, the Toledo OH area, and north of Akron — all inside the corridor TorCAST had flagged before radar confirmed activity.
TorCAST Timeline — June 14, 2026 (All times EDT / UTC · OH/PA corridor)
Time (EDT) Time (UTC) TPI (Max) Grid Points Tor-Warned Source Note
7:09 AM 11:09Z 4.0 3 0 Post First heads-up. TorCAST flagging organized tornado potential across OH/PA. No storms on radar.
10:10 AM 14:10Z 4.3 16 0 Archive TPI beginning to build. No warnings. Coverage expanding across corridor.
11:10 AM 15:10Z 4.5 43 0 Archive Grid coverage expanding. No warnings issued.
12:11 PM 16:11Z 5.0 116 0 Archive Corridor now 116 grid points. TPI at 5.0. No warnings. Atmosphere loading.
2:54 PM 18:54Z 5.4 122 0 Archive TPI 5.4 and holding. Still no warnings in the corridor.
3:39 PM 19:39Z 5.5 89 0 Archive Final pre-warning archive snapshot. TPI 5.5. No NWS tornado warnings yet issued.
4:25 PM 20:25Z 5.7 140 36 Archive First tornado warnings matched in corridor. 36 of 140 grid points under active warning.
5:13 PM 21:13Z 6.3 77 31 Archive Peak archive TPI. Jefferson Co. PA, Clearfield Co. PA warnings active.
6:13 PM 22:13Z 6.1 86 49 Archive 49 grid points under active tornado warnings. Akron-area warnings included.
Data sources: Post 7:09 AM EDT entry is from the TorCAST operational post timestamped that morning — the corridor assessment reflected the full TPI grid at that hour. Archive rows are from the TorCAST warning-validation log for the OH/PA region (lat 39–42.5°N, lon 84–77°W), indexed against NWS Cleveland (CLE), Pittsburgh (PBZ), and Wilmington (ILN) warning polygons. The gap between 3:39 PM EDT (last pre-warning read) and 4:25 PM EDT (first tor-warned read) reflects the period when the first NWS tornado warnings were issued in the corridor.
open_in_newSPC Storm Reports — June 14, 2026 open_in_newIEM LSR Archive — Tornado Reports open_in_newNWS Cleveland (CLE) open_in_newNWS Pittsburgh (PBZ)
Case Study 04 · Tornado · Central Illinois
Coles County, Illinois
PDS Tornado Warning
JUNE 17, 2026 · NWS Lincoln (LIN)
warning PDS — PARTICULARLY DANGEROUS SITUATION
Case
Coles County, IL
Event
PDS Tornado Warning
Peak TPI
7.1
First TorCAST heads-up
12:31 PM CDT
First warning
~7:07 PM CDT
Lead time
6h 36m
Verification
NWS Lincoln (LIN) PDS warning + SPC & IEM LSR reports
6h 36m
From first TorCAST heads-up to PDS Tornado Warning.
TorCAST flagged elevated tornado potential at 12:31 PM CDT. NWS Lincoln issued a Particularly Dangerous Situation Tornado Warning at approximately 7:07 PM CDT — confirming a large and extremely dangerous tornado on the ground near Westfield / Charleston in southeastern Coles County. TPI was holding at 6.7+ during the confirmed tornado.
TorCAST Timeline — June 17, 2026 (All times CDT / UTC)
Time (CDT) Time (UTC) TPI (Max) Grid Points Tor-Warned Source Note
12:31 PM 17:31Z 6.6 — None Post First heads-up. TPI 6.0–6.6, Belleville→Lincoln corridor. Christian Co. at 6.6. Before storm initiation.
2:51 PM 19:51Z 5.9 23 0 Archive No warnings issued. Tornado potential building in central IL.
3:36 PM 20:36Z 6.2 26 0 Archive No warnings issued. TPI climbing. LIN / QUA WFO coverage area.
4:36 PM 21:36Z 6.9 27 10 Archive First tornado warnings in the corridor. TPI at 6.9 — peak archive read.
5:39 PM 22:39Z 6.0 79 34 Archive Warning event expanding across corridor. 34 of 79 grid points under active tornado warnings.
5:50 PM 22:50Z 7.1 — Active Post "Significant intense tornado potential this evening across IL/MO." TPI 7.0–7.1 in Effingham Co.
~7:07 PM ~00:07Z+1 — — PDS NWS PDS Tornado Warning issued. Large confirmed tornado near Westfield/Charleston, Coles County. Moving E at ~45 mph.
6:34 PM 23:34Z 5.7 58 36 Archive TPI holding elevated during the active tornado. 36 of 58 grid points tornado-warned.
Data sources: Post rows are sourced from TorCAST operational posts timestamped in the record. These reflect the full TPI grid including pre-warning grid points that are not captured in the warning-validation archive (which only indexes points adjacent to issued NWS warnings). Archive rows are from the TorCAST warning-validation log: timestamped snapshots matched to NWS warning polygons within the Illinois WFO coverage zone (LIN / QUA / ST). NWS rows are from official NWS warning records.
open_in_newSPC Storm Reports — June 17, 2026 open_in_newIEM LSR Archive — Tornado Reports open_in_newNWS Chicago / NWS Lincoln (LIN)
Case Study 05 · Tornado / Severe · High Plains
Kansas / Nebraska / Colorado
Overnight Warning Corridor
JUNE 20-21, 2026 · NWS Goodland / Dodge City / Wichita / Denver
tornado OVERNIGHT TORNADO + SEVERE WARNING SEQUENCE
Case
KS / NE / CO High Plains
Event
Overnight Tornado + Severe Sequence
Peak TPI
7.9
First TorCAST heads-up
18:01Z Jun 20
First warning
21:58Z Jun 20
Lead time
3h 57m
Verification
NWS Goodland / Dodge City / Wichita / Denver warnings + SPC & IEM LSR reports
3h 57m
From first elevated High Plains archive read to first tornado-warning match.
TorCAST's warning-validation archive showed the KS/NE/CO High Plains corridor at TPI 5.5 by 18:01Z on June 20, with no tornado-warning matches in the corridor. The first tornado-warning-matched archive rows appeared at 21:58Z, when Goodland-area grid points were simultaneously matched to active tornado and severe thunderstorm warnings. The signal then persisted overnight, peaking at TPI 7.3 during the tornado-warning phase and later reaching TPI 7.9 while severe warnings continued into central Kansas.
TorCAST Timeline — June 20-21, 2026 (All times UTC · KS/NE/CO High Plains corridor)
Time (UTC) Local Window TPI (Max) Grid Points Tor-Warned Source Note
18:01Z 12:01 PM MDT / 1:01 PM CDT 5.5 30 0 Archive First elevated High Plains read. No tornado-warning matches; 1 severe-warning match in the Hastings coverage area.
20:58Z 2:58 PM MDT / 3:58 PM CDT 6.8 77 0 Archive TPI jumps to 6.8 with 24 severe-warning matches, but still zero tornado-warning matches.
21:58Z 3:58 PM MDT / 4:58 PM CDT 6.9 77 9 Archive First tornado-warning-matched archive window. 9 tor-warned and 31 severe-warned grid points, primarily matched to NWS Goodland.
22:58Z 4:58 PM MDT / 5:58 PM CDT 7.0 77 11 Archive Warning corridor expands. 11 tor-warned and 39 severe-warned points across Goodland, Denver, Hastings, Pueblo, and Cheyenne matches.
00:58Z 6:58 PM MDT / 7:58 PM CDT 7.3 144 22 Archive Peak tornado-warning phase. 22 tor-warned and 61 severe-warned grid points; max TPI 7.3 in the KS/NE warning corridor.
01:58Z 7:58 PM MDT / 8:58 PM CDT 6.9 55 10 Archive Tornado-warning matches continue into the evening. 10 tor-warned and 25 severe-warned points across Goodland, Dodge City, Denver, Hastings, and Cheyenne matches.
02:58Z 8:58 PM MDT / 9:58 PM CDT 6.8 54 8 Archive Late-evening tornado-warning matches persist. 8 tor-warned and 28 severe-warned points.
04:27Z 10:27 PM MDT / 11:27 PM CDT 7.1 16 0 Archive Tornado-warning matches have ended in this corridor, but severe-warning matches remain active. TPI 7.1 near the Dodge City / Wichita side of the overnight complex.
06:29Z 12:29 AM MDT / 1:29 AM CDT 7.9 23 0 Archive Overnight severe phase peaks. 17 severe-warning matches remain, with the max TPI 7.9 in central Kansas/Wichita coverage.
Data sources: All rows are from the local TorCAST warning-validation archive for the High Plains corridor (lat 37.5-41.0°N, lon 104.5-98.0°W), decoded from data/warning_validation_log.csv and checked against the timestamped Parquet snapshots in data/archive/2026-06-20 and data/archive/2026-06-21. The validation archive uses active NWS warning matches by WFO; this case includes Goodland (GOO), Dodge City (DOD), Wichita (WIC), Denver (DEN), Hastings (HAS), Pueblo (PUE), and Cheyenne (CHE) matches. Because the corridor crosses time zones, the timeline uses UTC as the primary clock.
open_in_newSPC Storm Reports — June 20, 2026 open_in_newSPC Storm Reports — June 21, 2026 open_in_newIEM LSR Archive — Overnight Tornado Reports open_in_newNWS Goodland (GOO)

About This Data

TorCAST maintains a warning-validation archive that indexes grid-point TPI scores against NWS-issued tornado and severe thunderstorm warnings. A grid point is marked tor-warned when it falls within an active NWS Tornado Warning polygon at the time of the archive snapshot. This archive does not capture pre-warning TPI values at points where no warning was subsequently issued — those appear in operational posts and the live TorCAST grid, which runs independently of warning issuance.

What this means for lead time: The archive-sourced "0 tor-warned" entries in the hours before first warnings represent the period when TorCAST was showing elevated potential against a background of no issued warnings — this is the pre-warning read that defines TorCAST's lead time value. The transition to "tor-warned" rows marks the point when NWS warnings caught up to the corridor TorCAST had already flagged.

Data not shown here: Events where archive data is incomplete, where tornado confirmation is pending, or where TorCAST scored the environment but storms underperformed — including days TorCAST correctly held confidence low despite surface parameters that appeared threatening. Those records exist in the archive and are reflected in the aggregate statistics above.

External links go to NOAA/NWS Storm Prediction Center storm report pages and the Iowa Environmental Mesonet LSR archive — independent sources that do not reference TorCAST data.

Case Study 06 · Tornado · Southwest Indiana
Gibson County, Indiana
PDS Tornado Warning
JUNE 21, 2026 · NWS Paducah (PAH)
warning PDS — PARTICULARLY DANGEROUS SITUATION
Case
Gibson County, IN
Event
PDS Tornado Warning
Peak TPI
7.1
First TorCAST heads-up
3:21 PM CDT
First warning
~7:13 PM CDT
Lead time
3h 52m
Verification
NWS Paducah (PAH) PDS warning + SPC & IEM LSR reports
3h 52m
From first TorCAST tornado-mode signal to the Gibson County PDS Tornado Warning.
TorCAST flagged the southwest Indiana corridor (Gibson / Pike / Knox) at High TPI with the Gibson County cell flipping to tornado-dominant at 5.8 by 3:21 PM CDT — and held it there with zero tornado warnings issued until ~3:47 PM CDT. NWS Paducah upgraded to a Particularly Dangerous Situation Tornado Warning at ~7:13 PM CDT, citing a confirmed large and extremely dangerous tornado over Fort Branch moving toward Princeton in southeastern Gibson County. By that time 34 of 35 corridor grid points were tornado-warned and TPI was holding 7.1 (High), tornado-dominant.
TorCAST Timeline — June 21, 2026 (All times CDT / UTC · SW Indiana corridor)
Time (CDT) Time (UTC) TPI (Max) Grid Points Tor-Warned Source Note
12:55 PM 17:55Z 5.2 3 0 Archive First Elevated read across the SW Indiana corridor (Gibson / Pike / Knox). No warnings issued.
1:55 PM 18:55Z 6.2 24 0 Archive Corridor loading fast — 24 grid points indexed, TPI to 6.2. Still zero tornado warnings (5+ hours of lead).
2:55 PM 19:55Z 7.1 28 0 Archive TPI at 7.1 (High), Gibson cell tornado-dominant. First severe-tstm warnings matched; no tornado warnings yet.
3:47 PM 20:47Z 7.1 31 11 Archive First tornado warnings matched in the corridor — 11 of 31 grid points tornado-warned. TorCAST held High for ~3 hrs first.
4:34 PM 21:34Z 7.3 33 21 Archive Warnings expanding across the corridor — 21 of 33 grid points tornado-warned.
5:34 PM 22:34Z 7.6 35 29 Archive Peak archive TPI of 7.6. 29 of 35 grid points under active tornado warnings.
6:19 PM 23:19Z 6.4 34 33 Archive Corridor near-fully warned — 33 of 34 grid points tornado-warned as supercells matured.
7:06 PM 00:06Z+1 7.1 35 34 Archive 34 of 35 grid points tornado-warned at touchdown time. TPI holding 7.1 (High), Gibson cell tornado-dominant.
~7:09 PM ~00:09Z+1 — — Confirmed NWS Confirmed tornado on the ground — Gibson County, 3 ESE Owensville (NWS / IEM LSR).
~7:13 PM ~00:13Z+1 — — PDS NWS PDS Tornado Warning issued (NWS Paducah). "Confirmed large and extremely dangerous tornado over Fort Branch... near Princeton" — SE Gibson County. Damage threat: CONSIDERABLE.
8:05 PM 01:05Z+1 6.7 36 33 Archive Event maturing — 33 of 36 grid points tornado-warned as the cluster tracked E into Pike / Spencer counties.
Data sources: Archive rows are from the TorCAST warning-validation log: timestamped display_tpi snapshots for the SW Indiana corridor (lat 38–40°N, lon 86.3–88.1°W), with each grid point matched against active NWS Paducah (PAH) tornado warning polygons. "Tor-Warned" is the number of those indexed grid points under an active NWS tornado warning at that snapshot. NWS rows are from official NWS warning records (the PDS Tornado Warning text, product 202606220013-KPAH-SVSPAH) and NWS / IEM Local Storm Reports. The log shows the corridor holding TPI 5.0–7.6 with the Gibson cell tornado-dominant for roughly 3 hours before the first tornado warning, climbing to 34 of 35 grid points tornado-warned at touchdown.
open_in_newSPC Storm Reports — June 21, 2026 open_in_newIEM LSR Archive — June 21 Tornado Reports open_in_newNWS Paducah, KY (PAH)