Corn Belt derecho: Difference between revisions
| (17 intermediate revisions by 11 users not shown) | |||
| Line 1: | Line 1: | ||
{{short description|Weather event}} |
|||
{{Derechobox |
|||
{{Infobox derecho |
|||
| name = Corn Belt Derecho |
| name = Corn Belt Derecho |
||
| image location = Corn Belt Derecho Path.png |
| image location = Corn Belt Derecho Path.png |
||
| image name = Path of the Corn Belt Derecho. |
| image name = Path of the Corn Belt Derecho. |
||
| ⚫ | |||
| radar name = Storm front crossing Illinois (looped animation) |
|||
| date = June 29, 1998 |
| date = June 29, 1998 |
||
| wind = 123 |
| wind = 123 |
||
| duration=~10 hours (12:00 PM-10:00 PM) |
| duration=~10 hours (12:00 PM-10:00 PM) |
||
| track = |
| track = 600 |
||
| windloc = [[Washington, Iowa]] |
| windloc = [[Washington, Iowa]] |
||
| hail = 2.5 |
| hail = 2.5 |
||
| Line 26: | Line 29: | ||
==Meteorological synopsis== |
==Meteorological synopsis== |
||
| ⚫ | At 1200 UTC (7:00 am. CDT), a stationary front extended from South Dakota to Southern Michigan, bringing warm and humid air to its South. The temperature was around {{convert|25|C|F}} at this early hour and the dew point was at {{convert|23|C|F}}. At 850 mb, the southwesterly flow was maintaining this situation while at higher levels the flow was turning to the northwest, bringing drier and colder air. Daytime heating would increase the instability of the airmass and the [[Convective available potential energy|CAPE]] was expected to reach a strong 3,689 J/kg.<ref name=Arnott>{{cite conference|last1=Arnott|first1=Justin M.|first2=N. T. |last2=Atkins|url=https://ams.confex.com/ams/pdfpapers/47035.pdf|conference=21st Conf. on Severe Local Storms|title=Tornadogenesis within quasi-linear convective systems. Part I: Radar and storm damage analysis of the 29 June 1998 derecho|date=August 15, 2002|publisher=[[American Meteorological Society|AMS]]|location=San Antonio, TX|conference-url=https://ams.confex.com/ams/SLS_WAF_NWP/webprogram/Paper47035.html|page= 13.4}}</ref> At the same time, there was relatively weak [[Synoptic scale meteorology|synoptic-scale]] forcing, the surface flow being a [[Col (meteorology)|barometric col]].<ref name=Arnott2>{{cite journal|last1=Arnott|first1=Justin M.|first2=N. T. |last2=Atkins|first3=Ron W. P |last3=Rzybylinski|first4=Ray A.|last4= Wolf|first5=Bradley D. |last5=Ketcham|s2cid=32372437|doi=10.1175/1520-0493(2004)132<2224:VSAEWB>2.0.CO;2|journal=Monthly Weather Review|title=Vortex Structure and Evolution within Bow Echoes. Part I: Single-Doppler and Damage Analysis of the 29 June 1998 Derecho |date=September 2004|volume=132|issue=9|pages=2224–2242|bibcode=2004MWRv..132.2224A|doi-access=free}}</ref> |
||
| ⚫ | |||
| ⚫ | At 1200 UTC (7:00 am. CDT), a stationary front extended from South Dakota to Southern Michigan, bringing warm and humid to its South. |
||
Along the front in South Dakota, an unorganized area of thunderstorms formed by 9:00 a.m. CDT. They rapidly organized and spread along the front, moving east-southeast into northeast [[Nebraska]].<ref name=Arnott2/> By midday, the storms reached northwestern and north central [[Iowa]], [[supercell]]s among them, while forming |
Along the front in South Dakota, an unorganized area of thunderstorms formed by 9:00 a.m. CDT. They rapidly organized and spread along the front, moving east-southeast into northeast [[Nebraska]].<ref name=Arnott2/> By midday, the storms reached northwestern and north central [[Iowa]], [[supercell]]s among them, while forming a west–east band and assuming a [[bow echo]] shape.<ref name=Corfidi/><ref name=Arnott2/> |
||
In the early afternoon, a second area of thunderstorms formed west of [[Des Moines]] and merged with the original bow echo line which |
In the early afternoon, a second area of thunderstorms formed west of [[Des Moines]] and merged with the original bow echo line which then accelerated east-southeast into Illinois by 4:00 p.m. The line evolved into a classic large scale bow echo, showing a "book end vortex" on its northern end,<ref name=Corfidi/> becoming a [[Derecho#Classification and criteria|progressive derecho]].<ref name=Arnott/> Damage, especially to crops and trees, became continuous from the Iowa border into Indiana as most of the damage was produced by strong straight-line winds on the leading edge of the [[Outflow boundary|gust front]]. Some embedded supercells, showing smaller-scale vortices on radars, produced narrower corridors of more intense damage, with measured wind gusts up to at least {{convert|110|mph|km/h}}.<ref name=Corfidi/><ref name=Arnott/> |
||
The derecho crossed central and southern Indiana during the early to mid evening while its highest wind gusts decreased somewhat compared with those observed earlier in the day. The system became a roughly west–east arc and turned more southward as it moved into [[Kentucky]] by late evening, dissipating gradually<ref name=Corfidi/> |
The derecho crossed central and southern Indiana during the early to mid evening while its highest wind gusts decreased somewhat compared with those observed earlier in the day. The system became a roughly west–east arc and turned more southward as it moved into [[Kentucky]] by late evening, dissipating gradually<ref name=Corfidi/> |
||
| Line 39: | Line 41: | ||
By the end of the morning, the thunderstorms produced hail up to the size of hen's eggs and locally damaging wind in Nebraska. By mid-day, supercells along the [[bow echo]] in Iowa began to produce very strong winds, up to tennis ball-sized hail, and several mostly short-lived tornadoes.<ref name=Corfidi/> On [[Weather radar#Velocity|Doppler weather radar]], a large fast-moving [[mesocyclone]] associated of the track of a [[supercell]] was nearly in contact with the ground as it moved from southwest [[Boone County, Iowa|Boone County]] east-southeast across the northern and eastern parts of the [[Des Moines metropolitan area|Des Moines metro area]].<ref name=Corfidi/> |
By the end of the morning, the thunderstorms produced hail up to the size of hen's eggs and locally damaging wind in Nebraska. By mid-day, supercells along the [[bow echo]] in Iowa began to produce very strong winds, up to tennis ball-sized hail, and several mostly short-lived tornadoes.<ref name=Corfidi/> On [[Weather radar#Velocity|Doppler weather radar]], a large fast-moving [[mesocyclone]] associated of the track of a [[supercell]] was nearly in contact with the ground as it moved from southwest [[Boone County, Iowa|Boone County]] east-southeast across the northern and eastern parts of the [[Des Moines metropolitan area|Des Moines metro area]].<ref name=Corfidi/> |
||
Over the [[Davenport, Iowa]] [[List of National Weather Service Weather Forecast Offices|NWS Weather Office]] area of responsibility, numerous reports of [[wind gust]]s ranging from 80 to 100 mph were received. The highest measured wind gust of {{convert|123|mph|km/h|0|abbr=on}} was reported in [[Washington, Iowa]] near coordinates {{coord|41.3|-91.7|region:US-IA|display=inline}}. This |
Over the [[Davenport, Iowa]] [[List of National Weather Service Weather Forecast Offices|NWS Weather Office]] area of responsibility, numerous reports of [[wind gust]]s ranging from 80 to 100 mph were received. The highest measured wind gust of {{convert|123|mph|km/h|0|abbr=on}} was reported in [[Washington, Iowa]] near coordinates {{coord|41.3|-91.7|region:US-IA|display=inline}}. This was the highest unofficial recorded wind gust in the history of the state of Iowa until the [[August 2020 Midwest derecho]].<ref>{{Cite web|url=https://cbs2iowa.com/news/local/top-wind-speeds-in-iowa-derecho-estimated-at-140-mph-in-cedar-rapids|title = Top wind speeds in Iowa Derecho estimated at 140 MPH in Cedar Rapids|date = 19 August 2020}}</ref><ref>{{cite web|url=https://www.weather.gov/dvn/ev19980629svr |title=June 29, 1998 Derecho|author= NWS Quad Cities IA/IL Weather Forecast Office|publisher=US [[National Weather Service]]|date=|accessdate=November 30, 2018}}</ref> At the same moment, the area of green in the radar display to the right shows the velocities toward the weather radar. The lighter shade, beneath the orange arrow, represented Doppler-estimated mean wind speeds in excess of {{convert|64|knot|km/h}} all along the gust front, and the yellow circle are [[Convective storm detection#Radar|mesocyclone detections]]. |
||
In Illinois, railroad cars were toppled, steel power transmission towers were bent, and many buildings were seriously damaged during the afternoon.<ref name=Corfidi/> By the evening into Indiana, hundreds of trees were uprooted in the [[Bedford, Indiana|Bedford]] and [[Indianapolis metropolitan area|Indianapolis]] areas, two semi-trailer trucks were blown off [[Interstate 65]] near [[Columbus, Indiana|Columbus]].<ref name=Corfidi/> By late evening, damage into Kentucky was minimal, mostly limited to toppled trees and several blown off |
In Illinois, railroad cars were toppled, steel power transmission towers were bent, and many buildings were seriously damaged during the afternoon.<ref name=Corfidi/> By the evening into Indiana, hundreds of trees were uprooted in the [[Bedford, Indiana|Bedford]] and [[Indianapolis metropolitan area|Indianapolis]] areas, two semi-trailer trucks were blown off [[Interstate 65]] near [[Columbus, Indiana|Columbus]].<ref name=Corfidi/> By late evening, damage into Kentucky was minimal, mostly limited to toppled trees and several roofs blown off buildings and houses.<ref name=Corfidi/> |
||
Along with the long-lived derecho, 20 [[tornadoes]] were reported, one of which was an [[Fujita scale|F2]] tornado, injuring 85 people in central [[Iowa]]. Over eight states, the derecho and associated tornadoes killed one person and injured 174.<ref name="severe plot">Data from the [[Storm Prediction Center]] archives, which are accessible through [http://www.spc.noaa.gov/software/svrplot2/ SeverePlot], free software created and maintained by John Hart, lead forecaster for the SPC.</ref><ref>{{cite web |url=http://www.tornadohistoryproject.com/tornado/1998/6/29/map|title=Tornadoes on June 29, 1998 |website=TornadoHistoryProject.com |accessdate=December 3, 2018}}</ref> |
Along with the long-lived derecho, 20 [[tornadoes]] were reported, one of which was an [[Fujita scale|F2]] tornado, injuring 85 people in central [[Iowa]]. Over eight states, the derecho and associated tornadoes killed one person and injured 174.<ref name="severe plot">Data from the [[Storm Prediction Center]] archives, which are accessible through [http://www.spc.noaa.gov/software/svrplot2/ SeverePlot], free software created and maintained by John Hart, lead forecaster for the SPC.</ref><ref>{{cite web |url=http://www.tornadohistoryproject.com/tornado/1998/6/29/map|title=Tornadoes on June 29, 1998 |website=TornadoHistoryProject.com |accessdate=December 3, 2018}}</ref> |
||
| Line 48: | Line 50: | ||
== See also == |
== See also == |
||
* [[List of derecho events]] |
* [[List of derecho events]] |
||
* [[Tornadoes of 1998]] |
|||
* [[August 2020 Midwest derecho]] |
|||
== References == |
== References == |
||
{{reflist}} |
{{reflist}} |
||
* {{cite journal |last = Ashley |first = Walker S. | |
* {{cite journal |last = Ashley |first = Walker S. |author-link = Walker S. Ashley |author2=T.L. Mote |author3=M.L. Bentley |title = The extensive episode of derecho-producing convective systems in the United States during May and June 1998: A multi-scale analysis and review |journal = Meteorol. Appl. |volume = 14 |issue = 3 |pages = 227–44 |date = Sep 2007 |doi = 10.1002/met.23 |bibcode = 2007MeApp..14..227A |url = http://commons.lib.niu.edu/handle/10843/13373 |doi-access = free }} |
||
== External links == |
== External links == |
||
Latest revision as of 04:44, 12 May 2024
 Path of the Corn Belt Derecho. | |
 Storm front crossing Illinois (looped animation) | |
| Date(s) | June 29, 1998 |
|---|---|
| Duration | ~10 hours (12:00 PM-10:00 PM) |
| Track length | 600 mi (966 km) |
| Peak wind gust (measured) | 123 mph (198 km/h; 55.0 m/s) (Washington, Iowa) |
| Largest hail | 2.5 in (6.3 cm) (Des Moines, Iowa) |
| Tornado count | 20 (Crawford County, Iowa) |
| Strongest tornado1 | F2 tornado |
| Fatalities | None (at least 85 injured) |
| Damage costs | $125 million |
| Areas affected | Midwestern United States |
| 1Most severe tornado damage; see Fujita scale | |
The Corn Belt derecho was a progressive derecho which affected a large area of the central United States on June 29, 1998. In the morning, thunderstorms, including a supercell, developed over South Dakota and tracked into central Iowa. As the thunderstorms reached central Iowa, a strong rear-inflow jet developed which caused the thunderstorm to take on a different characteristic, becoming a derecho. It traveled more than 600 miles in about ten hours, causing more than $125 million worth of widespread damage destruction, especially to crops, and was responsible for power outages to nearly a half a million people.[1]
Meteorological synopsis
[edit]At 1200 UTC (7:00 am. CDT), a stationary front extended from South Dakota to Southern Michigan, bringing warm and humid air to its South. The temperature was around 25 °C (77 °F) at this early hour and the dew point was at 23 °C (73 °F). At 850 mb, the southwesterly flow was maintaining this situation while at higher levels the flow was turning to the northwest, bringing drier and colder air. Daytime heating would increase the instability of the airmass and the CAPE was expected to reach a strong 3,689 J/kg.[2] At the same time, there was relatively weak synoptic-scale forcing, the surface flow being a barometric col.[3]
Along the front in South Dakota, an unorganized area of thunderstorms formed by 9:00 a.m. CDT. They rapidly organized and spread along the front, moving east-southeast into northeast Nebraska.[3] By midday, the storms reached northwestern and north central Iowa, supercells among them, while forming a west–east band and assuming a bow echo shape.[1][3]
In the early afternoon, a second area of thunderstorms formed west of Des Moines and merged with the original bow echo line which then accelerated east-southeast into Illinois by 4:00 p.m. The line evolved into a classic large scale bow echo, showing a "book end vortex" on its northern end,[1] becoming a progressive derecho.[2] Damage, especially to crops and trees, became continuous from the Iowa border into Indiana as most of the damage was produced by strong straight-line winds on the leading edge of the gust front. Some embedded supercells, showing smaller-scale vortices on radars, produced narrower corridors of more intense damage, with measured wind gusts up to at least 110 miles per hour (180 km/h).[1][2]
The derecho crossed central and southern Indiana during the early to mid evening while its highest wind gusts decreased somewhat compared with those observed earlier in the day. The system became a roughly west–east arc and turned more southward as it moved into Kentucky by late evening, dissipating gradually[1]
Impact
[edit]
By the end of the morning, the thunderstorms produced hail up to the size of hen's eggs and locally damaging wind in Nebraska. By mid-day, supercells along the bow echo in Iowa began to produce very strong winds, up to tennis ball-sized hail, and several mostly short-lived tornadoes.[1] On Doppler weather radar, a large fast-moving mesocyclone associated of the track of a supercell was nearly in contact with the ground as it moved from southwest Boone County east-southeast across the northern and eastern parts of the Des Moines metro area.[1]
Over the Davenport, Iowa NWS Weather Office area of responsibility, numerous reports of wind gusts ranging from 80 to 100 mph were received. The highest measured wind gust of 123 mph (198 km/h) was reported in Washington, Iowa near coordinates 41°18′N 91°42′W / 41.3°N 91.7°W. This was the highest unofficial recorded wind gust in the history of the state of Iowa until the August 2020 Midwest derecho.[4][5] At the same moment, the area of green in the radar display to the right shows the velocities toward the weather radar. The lighter shade, beneath the orange arrow, represented Doppler-estimated mean wind speeds in excess of 64 knots (119 km/h) all along the gust front, and the yellow circle are mesocyclone detections.
In Illinois, railroad cars were toppled, steel power transmission towers were bent, and many buildings were seriously damaged during the afternoon.[1] By the evening into Indiana, hundreds of trees were uprooted in the Bedford and Indianapolis areas, two semi-trailer trucks were blown off Interstate 65 near Columbus.[1] By late evening, damage into Kentucky was minimal, mostly limited to toppled trees and several roofs blown off buildings and houses.[1]
Along with the long-lived derecho, 20 tornadoes were reported, one of which was an F2 tornado, injuring 85 people in central Iowa. Over eight states, the derecho and associated tornadoes killed one person and injured 174.[6][7]
See also
[edit]References
[edit]- ^ a b c d e f g h i j Corfidi, Stephen. "The "Corn Belt Derecho" of June 1998". NOAA. Retrieved November 30, 2018.
- ^ a b c Arnott, Justin M.; Atkins, N. T. (August 15, 2002). Tornadogenesis within quasi-linear convective systems. Part I: Radar and storm damage analysis of the 29 June 1998 derecho (PDF). 21st Conf. on Severe Local Storms. San Antonio, TX: AMS. p. 13.4.
- ^ a b c Arnott, Justin M.; Atkins, N. T.; Rzybylinski, Ron W. P; Wolf, Ray A.; Ketcham, Bradley D. (September 2004). "Vortex Structure and Evolution within Bow Echoes. Part I: Single-Doppler and Damage Analysis of the 29 June 1998 Derecho". Monthly Weather Review. 132 (9): 2224–2242. Bibcode:2004MWRv..132.2224A. doi:10.1175/1520-0493(2004)132<2224:VSAEWB>2.0.CO;2. S2CID 32372437.
- ^ "Top wind speeds in Iowa Derecho estimated at 140 MPH in Cedar Rapids". 19 August 2020.
- ^ NWS Quad Cities IA/IL Weather Forecast Office. "June 29, 1998 Derecho". US National Weather Service. Retrieved November 30, 2018.
- ^ Data from the Storm Prediction Center archives, which are accessible through SeverePlot, free software created and maintained by John Hart, lead forecaster for the SPC.
- ^ "Tornadoes on June 29, 1998". TornadoHistoryProject.com. Retrieved December 3, 2018.
- Ashley, Walker S.; T.L. Mote; M.L. Bentley (Sep 2007). "The extensive episode of derecho-producing convective systems in the United States during May and June 1998: A multi-scale analysis and review". Meteorol. Appl. 14 (3): 227–44. Bibcode:2007MeApp..14..227A. doi:10.1002/met.23.
External links
[edit]- [1] Storm Prediction Center's 'About Derechos' web page summary of the event by Stephen Corfidi
- NWS Quad Cities overview
Copy from the above referenced website.