Jefferson County, Missouri
County storm and disaster record · FIPS 29099 · population 226,703 · 656 sq mi
NOAA's Storm Events Database holds 805 records for Jefferson County, Missouri from 1950 through June 30, 2026, on 490 days; the most frequent are hail reports (312 records). The deadliest single record is the July 1, 2015 flash flood: 2 deaths and $5.0 million in damage in 2025 dollars. FEMA has issued 30 declarations naming the county since 1973, 28 of them for natural hazards; the latest for a natural hazard was “Severe Storms, Straight-Line Winds, Tornadoes, and Wildfires” on May 21, 2025.
The record, 1950 to 2026
Storm records filed for the county each year (2026 to June 30, 2026). Before 1996 NOAA recorded only tornadoes (from 1950), thunderstorm wind and hail (from 1955).
- recorded, no damage figure
- under $100,000
- $100,000 or more
- $1 million or more
- $10 million or more, or a death
- $100 million or more, or 10 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- 1955: wind and hail recorded from 1955
- 1996: all 48 event types from 1996
- Storm records
- 805on 490 days, 1950 to June 30, 2026
- Deaths recorded
- 1119 injuries
- Damage, 2025 dollars
- $34Mas filed (scale steps before 1993)
- Tornadoes
- 44strongest F3
- FEMA declarations
- 30latest 2025
Source: NOAA NCEI Storm Events Database, records through June 30, 2026 (file revision 20260918); damage converted to 2025 dollars with the BLS CPI-U. Search the record at NCEI. BLS consumer price index.
What hazards hit Jefferson County most?
The most frequent records are hail reports: 312 since 1957. 56% of its hail reports since 1957 fell in April and May. The rank column places the county among Missouri's counties by days with a record per 1,000 square miles of land over each hazard's complete period.
| Hazard | Records | Days | First, last | Killed | Injured | Damage | Rank in state |
|---|---|---|---|---|---|---|---|
| Hail | 312 | 161 | 1957-2026 | 0 | 0 | $1.1M | 15 of 114 |
| Severe thunderstorm wind | 236 | 164 | 1960-2026 | 1 | 3 | $397K | 23 of 114 |
| Heat | 64 | 64 | 1998-2025 | 1 | 9 | – | 25 of 114 |
| Winter storms | 57 | 57 | 1996-2025 | 1 | 6 | – | 61 of 114 |
| Floods | 56 | 52 | 1996-2025 | 6 | 0 | $9.0M | 67 of 114 |
| Tornadoes | 44 | 34 | 1961-2025 | 1 | 1 | $23M | 20 of 114 |
| Drought | 10 | 10 | 2005-2018 | 0 | 0 | – | 93 of 114 |
| High wind and dust storms | 9 | 9 | 1996-2009 | 0 | 0 | $10K | 28 of 114 |
| Lightning | 8 | 7 | 1999-2016 | 1 | 0 | $90K | 10 of 114 |
| Extreme cold | 5 | 5 | 2000-2024 | 0 | 0 | – | 104 of 114 |
| Heavy rain | 4 | 4 | 2001-2024 | 0 | 0 | – | 50 of 114 |
Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.
How many tornadoes has Jefferson County had?
NOAA records 44 tornadoes in Jefferson County from 1961 to 2025, the strongest rated F3, with 1 death and 1 injury recorded in the county. That is 20th of 114 Missouri counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.
Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 45 tornadoes whose track touched Jefferson County since 1950 (NOAA's county records number 44: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 2 people, 1 of them in Jefferson County.
| Date | Tornado | Rating | Path | Killed |
|---|---|---|---|---|
| 2010-12-31 11:48, as SPC files it | Sunset Hills to Kirkwood | EF3 | 6.65 mi | 1 |
| 1981-04-22 17:54, as SPC files it | Festus to Herculaneum | F3 | 7.1 mi | 1 |
| 2006-03-11 21:42, as SPC files it | FultsCrossed IL, MO | F3 | 5.1 mi | 0 |
Map of the strongest tornado tracks in Missouri.
Every tornado record filed for Jefferson County (44)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2025-06-07 | Vineland, Jefferson County | EF1 4.88 mi x 300 yd | 0 | 0 | – |
| 2025-05-19 | De Soto Airport, Jefferson County | EFU 2.39 mi x 1 yd | 0 | 0 | – |
| 2025-03-14 | Morse Mill, Jefferson County | EF2 20.9 mi x 850 yd | 0 | 0 | $825K |
| 2024-05-26 | Paulina Hills, Jefferson County | EF0 0.21 mi x 100 yd | 0 | 0 | $9K |
| 2024-04-18 | Hoene Spg, Jefferson County | EF1 7.29 mi x 40 yd | 0 | 0 | $94K |
| 2023-04-15 | Pevely, Jefferson County | EF1 0.93 mi x 150 yd | 0 | 0 | – |
| 2023-04-15 | Silica, Jefferson County | EF1 3.97 mi x 360 yd | 0 | 1 | – |
| 2023-04-15 | Hillsboro, Jefferson County | EF0 0.57 mi x 200 yd | 0 | 0 | – |
| 2017-03-07 | Hillsboro, Jefferson County | EF0 1.14 mi x 75 yd | 0 | 0 | – |
| 2017-03-07 | Oermann, Jefferson County | EF0 2.63 mi x 80 yd | 0 | 0 | – |
| 2015-07-08 | Rush Tower, Jefferson County | EF0 0.15 mi x 50 yd | 0 | 0 | – |
| 2014-09-01 | Hoene Spg, Jefferson County | EF1 6.4 mi x 60 yd | 0 | 0 | – |
| 2013-05-31 | Byrnesville, Jefferson County | EF1 12.41 mi x 200 yd | 0 | 0 | – |
| 2010-12-31 | Murphy, Jefferson County | EF0 0.86 mi x 50 yd | 0 | 0 | – |
| 2010-12-31 | Oermann, Jefferson County | EF1 6.6 mi x 50 yd | 0 | 0 | – |
| 2010-12-31 | Hoene Spg, Jefferson County | EF1 0.81 mi x 150 yd | 0 | 0 | – |
| 2010-04-30 | Fletcher, Jefferson County | EF1 17.6 mi x 581 yd | 0 | 0 | – |
| 2006-09-22 | Fletcher, Jefferson County | F1 0.7 mi x 100 yd | 0 | 0 | – |
| 2006-09-22 | Fletcher, Jefferson County | F1 0.1 mi x 50 yd | 0 | 0 | – |
| 2006-03-11 | Festus, Jefferson County | F3 3.1 mi x 200 yd | 0 | 0 | – |
| 2006-03-11 | Festus, Jefferson County | F0 0.1 mi x 10 yd | 0 | 0 | – |
| 2004-05-27 | Hillsboro, Jefferson County | F0 0.2 mi x 50 yd | 0 | 0 | – |
| 2003-05-06 | De Soto, Jefferson County | F0 0.2 mi x 50 yd | 0 | 0 | – |
| 2003-05-06 | Ware, Jefferson County | F0 0.1 mi x 50 yd | 0 | 0 | – |
| 1995-04-16 | De Soto, Jefferson County | F0 0.1 mi x 10 yd | 0 | 0 | $387 |
| 1994-04-26 | Crystal City, Jefferson County | F0 0.3 mi x 30 yd | 0 | 0 | $10K |
| 1994-04-15 | Barnhart To, Jefferson County | F1 2.3 mi x 100 yd | 0 | 0 | $10.0M |
| 1994-04-15 | Ottoville To, Jefferson County | F0 2 mi x 50 yd | 0 | 0 | $101K |
| 1994-04-15 | Cedar Hill To, Jefferson County | F0 4 mi x 50 yd | 0 | 0 | $1.0M |
| 1984-11-09 | Jefferson County | F0 0.3 mi x 77 yd | 0 | 0 | – |
| 1982-12-02 | Jefferson County | F1 0.5 mi x 50 yd | 0 | 0 | $250K step |
| 1981-07-20 | Jefferson County | F1 1 mi x 50 yd | 0 | 0 | $3K step |
| 1981-04-22 | Jefferson County | F3 7.1 mi x 100 yd | 1 | 0 | $2.5M step |
| 1978-05-12 | Jefferson County | 0 | 0 | $250K step | |
| 1976-07-27 | Jefferson County | F1 0.2 mi x 20 yd | 0 | 0 | – |
| 1973-06-04 | Jefferson County | F1 | 0 | 0 | – |
| 1968-05-15 | Jefferson County | F1 5.9 mi x 100 yd | 0 | 0 | $25K step |
| 1968-04-03 | Jefferson County | F1 7.6 mi x 100 yd | 0 | 0 | $25K step |
| 1967-10-24 | Jefferson County | F1 2 mi x 50 yd | 0 | 0 | $25K step |
| 1967-06-10 | Jefferson County | F2 0.2 mi x 17 yd | 0 | 0 | $25K step |
| 1967-05-28 | Jefferson County | F2 2.5 mi x 50 yd | 0 | 0 | $25K step |
| 1965-09-04 | Jefferson County | F1 3.6 mi x 750 yd | 0 | 0 | $3K step |
| 1961-05-07 | Jefferson County | F1 5.6 mi x 50 yd | 0 | 0 | $3K step |
| 1961-05-06 | Jefferson County | F1 5.7 mi x 50 yd | 0 | 0 | $25K step |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.
When was the last damaging storm in Jefferson County?
The most recent record with damage, injuries or deaths is the December 1, 2025 winter weather (1 death).
Snow covered roads led to multiple accidents. Although only 2 to 3 inches of snow was reported, accidents caused one fatality and road closures led to long traffic delays.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 1305217)
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-04-27 | Thunderstorm WindBayshore, Jefferson County | 52 kt wind | 0 | 0 | – |
| 2026-04-27 | HailHouse Spgs, Jefferson County | 1.00 in hail | 0 | 0 | – |
| 2026-04-27 | HailDittmer, Jefferson County | 1.00 in hail | 0 | 0 | – |
| 2026-03-11 | Thunderstorm WindValles Mines, Jefferson County | 50 kt wind | 0 | 0 | – |
| 2025-12-01 | Winter WeatherJefferson County · forecast zone Jefferson | 1 | 0 | – | |
| 2025-08-16 | Excessive HeatJefferson County · forecast zone Jefferson | 0 | 0 | – | |
| 2025-07-29 | Thunderstorm WindPevely, Jefferson County | 60 kt wind | 0 | 0 | – |
| 2025-07-22 | Excessive HeatJefferson County · forecast zone Jefferson | 0 | 0 | – | |
| 2025-06-07 | HailVineland, Jefferson County | 1.00 in hail | 0 | 0 | – |
| 2025-06-07 | TornadoVineland, Jefferson County | EF1 4.88 mi x 300 yd | 0 | 0 | – |
| 2025-05-19 | Thunderstorm WindMurphy, Jefferson County | 60 kt wind | 0 | 0 | – |
| 2025-05-19 | Thunderstorm WindDe Soto Airport, Jefferson County | 55 kt wind | 0 | 0 | $2K |
Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.
The deadliest and costliest records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2015-07-01 | Flash FloodKimmswick, Jefferson County Up to 7 inches of rain fell in a short amount of time onto already saturated soils causing flash flooding. The main band of heavy rain extended from northwest of Cedar Hill southeastward to southeastern Jefferson County, south of Festus. Four vehicles were swept off of Meyer Road, just west of intersection with U.S. ... | 2 | 0 | $5.0M | |
| 2025-12-01 | Winter WeatherJefferson County · forecast zone Jefferson Snow covered roads led to multiple accidents. Although only 2 to 3 inches of snow was reported, accidents caused one fatality and road closures led to long traffic delays. | 1 | 0 | – | |
| 2020-08-10 | Thunderstorm WindArnold, Jefferson County A line of severe storms moved across Jefferson County. Numerous trees, tree limbs and power lines were blown down. In Pevely, a 51 year old woman was killed when a tree was uprooted by the thunderstorm winds and it fell on her. She had been helping her boyfriend move a hard top from a Jeep to prevent damage to it from ... | 61 kt wind | 1 | 0 | – |
| 2017-04-30 | FloodHoene Spg, Jefferson County The Meramec and Big Rivers rose above major flood stage in the late evening hours of April 30th due to the heavy rainfall. A number of roads were closed due to the river flooding. A 77-year old man drowned when he walked to a creek (that feeds into the nearby Big River) near his house (off of Mimi Mountain Road and ... | 1 | 0 | – | |
| 2016-06-25 | LightningDanby, Jefferson County A 72 year old man and his dog were struck and killed by lightning as storms moved through the area. They were in the front yard of the residence when it happened. | 1 | 0 | – | |
| 2013-04-18 | Flash FloodDe Soto Airport, Jefferson County Up to five inches of rain fell in a 24 hour period. This caused flash flooding on Joachim Creek in DeSoto. The creek rose quickly and numerous roads on the east side of town were flooded. The water rose high enough that the fire station on East Miller Street had over a foot of water in it throughout the offices and ... | 1 | 0 | – | |
| 2006-07-14 | HeatJefferson County · forecast zone Jefferson A major heat wave hit the St. Louis area in mid-July. Temperatures ranged from the middle 90s to a high of 100 on July 19. To make matters worse, severe thunderstorms roared across the region on the 19th and 21st causing a historic power outage. Up to 700,000 metered buildings were without power. In some cases power ... | 1 | 0 | – | |
| 2003-05-06 | Flash FloodDe Soto, Jefferson County Heavy rain caused flash flooding across the northern two-thirds of Jefferson County. Up to 4 feet of water was reported on Main Street in De Soto. Numerous homes had flooded basements as small creeks and drainage ditches overflowed. In Festus, 3 feet of water was reported on Highway 61/67. A 42 year old man was killed ... | 1 | 0 | – |
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1994-04-15 | TornadoBarnhart To, Jefferson County | F1 2.3 mi x 100 yd | 0 | 0 | $10.0M |
| 2015-07-01 | Flash FloodKimmswick, Jefferson County | 2 | 0 | $5.0M | |
| 2015-12-28 | FloodWickes, Jefferson County | 0 | 0 | $2.7M | |
| 1994-04-15 | TornadoCedar Hill To, Jefferson County | F0 4 mi x 50 yd | 0 | 0 | $1.0M |
| 1994-04-26 | HailArnold, Jefferson County | 4.50 in hail | 0 | 0 | $1.0M |
| 2000-05-07 | Flash FloodWest Central Portion, Jefferson County | 0 | 0 | $857K | |
| 2025-03-14 | TornadoMorse Mill, Jefferson County | EF2 20.9 mi x 850 yd | 0 | 0 | $825K |
| 1994-04-15 | TornadoOttoville To, Jefferson County | F0 2 mi x 50 yd | 0 | 0 | $101K |
Before 1993 NOAA filed damage by category, not amount, so the list above starts in 1993. The highest category filed here before then (entered as $2.5M, in the dollars of the day) holds: April 22, 1981 (tornado, Jefferson County, 1 killed).
Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.
Is it getting more frequent?
Records per decade for Jefferson County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).
| Hazard | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020-26 |
|---|---|---|---|---|---|---|---|---|
| Hail | 2 | 1 | 11 | 23 | 51 | 100 | 78 | 46 |
| Severe thunderstorm wind | 0 | 4 | 14 | 29 | 28 | 72 | 48 | 41 |
| Heat | – | – | – | – | 2 | 22 | 36 | 4 |
| Winter storms | – | – | – | – | 13 | 24 | 13 | 7 |
| Floods | – | – | – | – | 7 | 23 | 18 | 8 |
| Tornadoes | 0 | 8 | 3 | 4 | 5 | 7 | 9 | 8 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
56% of its hail reports since 1957 fell in April and May. The two busiest months are in violet.
The values, month by month
Jan 27 · Feb 32 · Mar 75 · Apr 167 · May 126 · Jun 93 · Jul 114 · Aug 63 · Sep 39 · Oct 18 · Nov 20 · Dec 31 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Jefferson County
FEMA's register lists 30 declarations that include Jefferson County: 22 major disasters, 8 emergencies and 0 fire management assistance declarations. Most were for severe storm (16) and flood (7).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2025-05-21 | DR-4867 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Wildfires |
| 2020-03-26 | DR-4490 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3482 | Biological | Covid-19 |
| 2019-07-09 | DR-4451 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| 2017-06-02 | DR-4317 | Flood | Severe Storms, Tornadoes, Straight-Line Winds and Flooding |
| 2016-01-21 | DR-4250 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| 2016-01-02 | EM-3374 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| 2015-08-07 | DR-4238 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| 2011-02-03 | EM-3317 | Severe Storm | Severe Winter Storm |
| 2009-06-19 | DR-1847 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| 2009-01-30 | EM-3303 | Severe Ice Storm | Severe Winter Storm |
| 2008-11-13 | DR-1809 | Severe Storm | Severe Storms, Flooding, and A Tornado |
| 2008-06-25 | DR-1773 | Severe Storm | Severe Storms and Flooding |
| 2008-03-19 | DR-1749 | Severe Storm | Severe Storms and Flooding |
| 2007-12-12 | EM-3281 | Severe Ice Storm | Severe Winter Storms |
| 2006-07-21 | EM-3267 | Severe Storm | Severe Storms |
| 2006-03-16 | DR-1631 | Severe Storm | Severe Storms, Tornadoes and Flooding |
| 2005-09-10 | EM-3232 | Hurricane | Hurricane Katrina Evacuation |
| 2003-05-06 | DR-1463 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| 2002-05-06 | DR-1412 | Severe Storm | Severe Storms, Tornadoes and Flooding |
| 2000-05-12 | DR-1328 | Flood | Severe Thunderstorms and Flash Flooding |
| 1995-06-02 | DR-1054 | Severe Storm | Severe Storms, Tornadoes, Hail, Flooding |
| 1994-04-21 | DR-1023 | Severe Storm | Severe Storms, Tornadoes, Flooding |
| 1993-12-01 | DR-1006 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| 1993-07-09 | DR-995 | Flood | Severe Storms & Flooding |
| 1993-05-11 | DR-989 | Flood | Severe Storms & Flooding |
| 1982-12-10 | DR-672 | Flood | Severe Storms and Flooding |
| 1979-04-21 | DR-579 | Tornado | Tornadoes, Torrential Rain & Flooding |
| 1976-09-24 | EM-3017 | Drought | Drought |
| 1973-04-19 | DR-372 | Severe Storm | Heavy Rains, Tornadoes & Flooding |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.
How many floods has Jefferson County had?
NOAA's Storm Events Database holds 56 flood or flash flood records for Jefferson County from 1996 to 2025, on 52 days, with 6 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Jefferson County ranks 101st of 2,942 U.S. counties.
The National Flood Insurance Program has paid $69.3 million on 4,592 claims filed in Jefferson County; the most in one year was 792 in 1993. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1978: 26 · 1979: 320 · 1980: 16 · 1981: 54 · 1982: 438 · 1983: 425 · 1984: 36 · 1985: 266 · 1986: 106 · 1987: 1 · 1988: 1 · 1989: 3 · 1990: 84 · 1991: 3 · 1992: 8 · 1993: 792 · 1994: 348 · 1995: 179 · 1996: 125 · 1997: 18 · 1998: 26 · 1999: 11 · 2000: 82 · 2001: 7 · 2002: 42 · 2003: 63 · 2004: 7 · 2005: 27 · 2006: 9 · 2007: 1 · 2008: 290 · 2009: 46 · 2010: 2 · 2011: 14 · 2013: 80 · 2014: 12 · 2015: 242 · 2016: 41 · 2017: 196 · 2018: 8 · 2019: 31 · 2020: 9 · 2021: 6 · 2022: 28 · 2023: 3 · 2024: 56 · 2025: 3 · 2026: 1; the other years: 0.
Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.
FEMA's modeled risk for Jefferson County
FEMA's National Risk Index rates Jefferson County Relatively Moderate overall, with an expected annual loss of $114 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.
| Hazard | Risk rating | Expected annual loss | Modeled frequency |
|---|---|---|---|
| Strong Wind | Very High | $8.7M | 5.6 a year (modeled) |
| Tornado | Relatively High | $16M | once in about 2 years (modeled) |
| Lightning | Relatively High | $1.7M | 54 a year (modeled) |
| Landslide | Relatively Moderate | $224K | 2.5 a year (modeled) |
| Hail | Relatively Moderate | $3.2M | 5.2 a year (modeled) |
| Earthquake | Relatively Moderate | $12M | once in about 168 years (modeled) |
| Heat Wave | Relatively Moderate | $4.8M | 13 modeled event-days a year |
| Riverine Flooding | Relatively Moderate | $59M | 1.8 a year (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Jefferson County
Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.
Next
- Tornadoes in MissouriEvery Missouri tornado since 1950 and the counties with the most per square mile
- Hail in MissouriThe state's hail reports, by county, year and month
- The Missouri recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Jefferson CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Jefferson County's FEMA declarations (CSV)30 rows: every declaration that named the county, for your own analysis