Wildfire smoke EPA monitor flag
Daily PM2.5 peaked at 84.5 µg/m³ near Charlotte across 7 covered metros home to 8.6 million people. 2 metros recorded their worst day on record; 5 placed a top-ten day.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 4.3 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 37 million cigarettes. An awareness illustration of outdoor exposure at 22 µg/m³ per cigarette (Berkeley Earth), counting only the event's ranked days; not a medical dose.
Why we think this happened
The North Carolina assessment attributes early-November particulate impacts, including November 2–4, to smoke from forest fires in North Carolina and neighboring states; both events fall within that assessed occurrence. The North Carolina assessment attributes early-November particulate impacts, including the Winston-Salem value and November 2–4 period, to smoke from forest fires in North Carolina and neighboring states.
EPA monitor flag EPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.
U.S. EPA Air Quality System and the submitting air monitoring agency · Nov 3, 2000 official
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 2 PM2.5 samples in the candidate CBSA on 2000-11-03, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
U.S. EPA Air Quality System and the submitting air monitoring agency · Nov 2, 2000 official
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 4 PM2.5 samples in the candidate CBSA on 2000-11-02, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
U.S. EPA Air Quality System and the submitting air monitoring agency · Nov 4, 2000 official
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 1 PM2.5 sample in the candidate CBSA on 2000-11-04, identifying wildfire smoke as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
See every retained source and limitation ↓
Sequence: Charlotte (Nov 2) → Augusta (Nov 2) → Winston (Nov 3) → Greensboro (Nov 3) → Richmond (Nov 3) → Durham (Nov 3) → Raleigh (Nov 3)
Evidence path
A cause is more convincing when the record connects three things: something happened, the air mass moved toward the region, and local instruments responded. Here is how much of that chain is documented for this event.
Source or mechanism
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 2 PM2.5 samples in the candidate CBSA on 2000-11-03, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official…
View supporting source ↗Air-mass movement
NOAA HYSPLIT modeled 84 backward paths across multiple arrival times and heights. They show where the air traveled, not which source polluted it.
Explore the modeled paths ↓Local response
EPA monitors recorded the event across 7 metros. The peak daily concentration is roughly 3.8 cigarette-equivalents at the outdoor daily rate.
Inspect the pollutant and weather signals ↓Event autopsy
Before, during, and after the episode: nearby pollutant monitors and surface-weather stations show what changed. This context tests the “Wildfire smoke” explanation; it does not assign the cause by itself.
Augusta-Richmond County, GA-SC
Monitor comparison window 2000-10-30 to 2000-11-07 · PM2.5 target: Medical College of Georgia
35% above nearby days
No adjacent-day comparison
35% higher than surrounding days
No adjacent-day comparison
About the same as surrounding days
39% higher than surrounding days
Charlotte-Concord-Gastonia, NC-SC
Monitor comparison window 2000-10-30 to 2000-11-07
123% above nearby days
33% lower than surrounding days
No adjacent-day comparison
123% higher than surrounding days
No adjacent-day comparison
74% higher than surrounding days
34% higher than surrounding days
52% higher than surrounding days
40% higher than surrounding days
About the same as surrounding days
10% higher than surrounding days
33% lower than surrounding days
Durham-Chapel Hill, NC
Monitor comparison window 2000-10-31 to 2000-11-07
96% above nearby days
96% higher than surrounding days
Greensboro-High Point, NC
Monitor comparison window 2000-10-31 to 2000-11-07
96% above nearby days
23% higher than surrounding days
96% higher than surrounding days
23% higher than surrounding days
Raleigh, NC
Monitor comparison window 2000-10-31 to 2000-11-07 · PM2.5 target: Millbrook School
17% above nearby days
23% higher than surrounding days
17% higher than surrounding days
23% higher than surrounding days
41% higher than surrounding days
26% higher than surrounding days
10% higher than surrounding days
11% higher than surrounding days
Richmond, VA
Monitor comparison window 2000-10-31 to 2000-11-07
94% above nearby days
88% higher than surrounding days
94% higher than surrounding days
88% higher than surrounding days
7% higher than surrounding days
36% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
Winston-Salem, NC
Monitor comparison window 2000-10-31 to 2000-11-07 · PM2.5 target: Hattie Avenue
180% above nearby days
9% lower than surrounding days
134% higher than surrounding days
180% higher than surrounding days
134% higher than surrounding days
24% higher than surrounding days
44% higher than surrounding days
13% higher than surrounding days
35% higher than surrounding days
10% higher than surrounding days
9% lower than surrounding days
Source: U.S. EPA AirData daily observations and, where available, nearby ASOS/AWOS surface observations. Values are descriptive medians over the retained monitor set; missing measurements remain missing. Transport and source evidence remain separate layers because this instrument pattern does not assign a cause by itself.
Air-mass reconstruction
NOAA HYSPLIT traces the air arriving at each metro backward for 72 hours. Multiple arrival times and heights show whether the broad path is stable—or sensitive to assumptions about when and where the polluted layer arrived.
Air arriving near Augusta-Richmond County
Peak-date arrivals · 2000-11-02
Each line begins 72 hours before arrival and points toward the metro. Color represents arrival height; repeated lines represent 00, 06, 12, and 18 UTC arrival assumptions. A path can show where the air traveled, but it cannot prove which source added the PM2.5.
Air arriving near Charlotte-Concord-Gastonia
Peak-date arrivals · 2000-11-03
Each line begins 72 hours before arrival and points toward the metro. Color represents arrival height; repeated lines represent 00, 06, 12, and 18 UTC arrival assumptions. A path can show where the air traveled, but it cannot prove which source added the PM2.5.
Air arriving near Durham-Chapel Hill
Peak-date arrivals · 2000-11-04
Each line begins 72 hours before arrival and points toward the metro. Color represents arrival height; repeated lines represent 00, 06, 12, and 18 UTC arrival assumptions. A path can show where the air traveled, but it cannot prove which source added the PM2.5.
Air arriving near Greensboro-High Point
Peak-date arrivals · 2000-11-03
Each line begins 72 hours before arrival and points toward the metro. Color represents arrival height; repeated lines represent 00, 06, 12, and 18 UTC arrival assumptions. A path can show where the air traveled, but it cannot prove which source added the PM2.5.
Air arriving near Raleigh
Peak-date arrivals · 2000-11-03
Each line begins 72 hours before arrival and points toward the metro. Color represents arrival height; repeated lines represent 00, 06, 12, and 18 UTC arrival assumptions. A path can show where the air traveled, but it cannot prove which source added the PM2.5.
Air arriving near Richmond
Peak-date arrivals · 2000-11-04
Each line begins 72 hours before arrival and points toward the metro. Color represents arrival height; repeated lines represent 00, 06, 12, and 18 UTC arrival assumptions. A path can show where the air traveled, but it cannot prove which source added the PM2.5.
Air arriving near Winston-Salem
Peak-date arrivals · 2000-11-03
Each line begins 72 hours before arrival and points toward the metro. Color represents arrival height; repeated lines represent 00, 06, 12, and 18 UTC arrival assumptions. A path can show where the air traveled, but it cannot prove which source added the PM2.5.
Episode peak
-- cigarettes
The smoke map's scale, replayed over this event: the surface interpolates between covered metros' daily records, framed to the affected region. Hover for a reading, click a metro to pin it to the card. Days a monitor did not report draw nothing.
Views from the selected metro
Select a metro on the map to see nearby cameras. Where an operator archive reaches the event, drag the divider to compare two moments, adjust either date and time, or play the available event-day frames. Camera imagery is visual context, not an air-quality measurement or proof of smoke.
No useful public camera views are currently available within 80 km of this metro.
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Charlotte-Concord-Gastonia, NC-SC | 84.5 µg/m³ | 8.7 | Nov 3, 2000 | Worst day on record |
| Winston-Salem, NC | 69.7 µg/m³ | 5.7 | Nov 3, 2000 | Worst day on record |
| Greensboro-High Point, NC | 50.8 µg/m³ | 2.3 | Nov 3, 2000 | #3 of its top days |
| Richmond, VA | 48.9 µg/m³ | 4.0 | Nov 4, 2000 | #7 of its top days |
| Durham-Chapel Hill, NC | 43 µg/m³ | 3.6 | Nov 4, 2000 | #5 of its top days |
| Augusta-Richmond County, GA-SC | 41.9 µg/m³ | 1.9 | Nov 2, 2000 | #20 of its top days |
| Raleigh, NC | 40.2 µg/m³ | 3.7 | Nov 3, 2000 | #16 of its top days |
"Cigarettes, whole event" totals a metro's ranked event days at 22 µg/m³ per cigarette: what a person outdoors there breathed across the event, as the illustration. "All-time standing" is where this episode's days sit in each metro's ranked record (worst-area measure, since 1999). Full local context is on each metro's Air Records page.
Public evidence library
Each card states what a source supports—and what it does not. Official records, research, reporting, community observations, and transparent inferences remain visibly different kinds of evidence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 2 PM2.5 samples in the candidate CBSA on 2000-11-03, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 4 PM2.5 samples in the candidate CBSA on 2000-11-02, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 1 PM2.5 sample in the candidate CBSA on 2000-11-04, identifying wildfire smoke as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 1 PM2.5 sample in the candidate CBSA on 2000-11-04, identifying wildfire smoke as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 1 PM2.5 sample in the candidate CBSA on 2000-11-04, identifying wildfire smoke as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 1 PM2.5 sample in the candidate CBSA on 2000-11-03, identifying wildfire smoke as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 1 PM2.5 sample in the candidate CBSA on 2000-11-03, identifying wildfire smoke as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 1 PM2.5 sample in the candidate CBSA on 2000-11-03, identifying wildfire smoke as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 1 PM2.5 sample in the candidate CBSA on 2000-11-04, identifying wildfire smoke as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier E — Forest Fire.
EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 1 PM2.5 sample in the candidate CBSA on 2000-11-04, identifying wildfire smoke as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
2000 Ambient Air Quality Report
The state assessment says forest-fire smoke in North Carolina and neighboring states affected particulate samplers in early November 2000, especially November 2–4 and 8; it identifies a 84.5 µg/m3 PM2.5 value in Charlotte among fire-caused flagged values.
EPA monitor flag EPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.
This episode was grouped from the monitor record by the catalog pipeline and given its cause from the evidence listed above. It has not been individually reviewed and signed off, so its boundaries, cause, and name may change as evidence accumulates. Grouping policy common_sense_root_cause_grouping.v2. The cause label reflects the assembled evidence above, not an IAQng detection formula. If it is wrong, tell us.