23 March 1913 Omaha-area Tornadoes
An observational and modeling case study
Evan Kuchera (evan.kuchera@gmail.com)
Jeff Hamilton
Trudy E. Bell
Event Summary
8 F3/F4 tornadoes leading to 201 deaths (Terre Haute, IN not shown)--weaker tornadoes in red (Kansas tornadoes not shown)
Deadliest natural disaster in Nebraska state history. 13th deadliest tornado in US history; 3 violent tornadoes struck the same metro area in a one-hour period
Approx tracks on Omaha metro map
5:30 PM
5:40 PM
6:15 PM
Event Summary
“Weather bureau officials say the last week or 10 days has presented the most extraordinary situation in regards to the weather since the creation of the bureau”
--25 March Crawfordsville, IN Journal
13-14 March blizzard/tornado outbreak (Plains and Southeast)
20-21 March ice storm/synoptic windstorm/tornado outbreak (Midwest/Deep South)
23-24 March tornado outbreak and derecho (Nebraska/Iowa/Illinois/Indiana)
24-26 March heavy rains/flooding (Indiana/Ohio)
Storm sequence killed over 1000 people and caused over $100 billion in damage (2012 dollars)
Storms of 20-21 March took out telegraph infrastructure, hindering communication for events on 24-26 March
Outline
Motivation/History
Observations
Model re-analysis data
Storm scale modeling
Summary and conclusions
Motivation
More complete understanding of meteorological conditions leading to this extreme event may help in anticipating and preparing for future events
Explore the extent to which modern storm-scale modeling can simulate extreme historical event given coarse but surprisingly accurate 3-D reanalysis data
History up to 1913
Finley and others in the late 1800s had studied the climatology of tornadoes and recognized favorable surface weather patterns for tornado occurrence
SE quadrant of a synoptic low pressure system
Strong gradients of temperature and moisture
Strong southerly winds
After a down period, in the 1940s and 1950s tornado research begins again, with watch and warning systems developed
First tornado forecast in 1948--remarkable story!
In 1913 in tornado prone regions of the country, the layperson recognized:
Tornadoes generally occurred on unusually warm and humid days
Parent thunderstorms often appeared unusual and moved from SW to NE
Taking shelter below ground was the appropriate action to take
Calm before the storm
History up to 1913
Weather Bureau issued daily warnings for "severe local storms" as far back as 1871--none issued on the day of Omaha tornadoes
Attempts at tornado forecasting fell out of favor around 1900 (MWR, 1899)
Unable to anticipate tornado evolution (changes in direction/intensity)
Lack of communication technology (telegraph too slow, risky)
Observing stations too few and far between
Concerns over false alarms (more harm done than good)
Additionally, the Weather Bureau made no effort to educate the public on preventative measures
Local populations did not want the stigma of being in tornado-prone areas
With the benefit of hindsight, it is an interesting question--should the Weather Bureau have been making SPC outlook-style forecasts for tornadoes and other severe weather, and been providing more education on protective measures?
More history
Then Sec of State Bryan watched the “funnel clouds gradually descending and sweeping the ground” pass to the south of his home in Lincoln (48th/South)
Damage at College View and University Place in Lincoln
Tornado missed home of Gerald Ford’s parents by 5 blocks (Ford born in July)
First Associated Press nationwide bulletins were for the Omaha tornado
Trunk carried from Yutan, NE into Iowa (40+ miles)
First (maybe) video of an ongoing natural disaster for the flooding in IN/OH
Private citizens used telegraph communications to warn relatives in other states of impending severe weather
Union Pacific President in Omaha was monitoring barometer and sent warning out to its trains to be on the lookout for tornadoes that afternoon
Tornadoes and other storms severely hampered telegraph communications; trainloads of people from Omaha arriving in Lincoln were first to get the word out
Several inches of snow fell in the morning on 25 March, hindering cleanup
Omaha mindset in 1913
"Then as I came opposite that large tree at the side of the path (the one cemented up at the roots) the heavy blackness in the southwest assumed a funnel shape. But still I would not think cyclone as cyclones only come after very very hot oppressive days"
--Beulah Adams, Omaha grade school teacher (Douglas Co. Historical Society)
"At approximately 5:30 the clouds had lifted from the horizon everywhere except for a very short stretch in the southwest. This last fact, the peculiar color of the cIouds-a muddy buff-and the time of day led me to suspect the approach of a tornado, but it was hardly more than a passing thought. The season seemed too early for such phenomena in this latitude; the wind was strong when I thought it should have been a comparative calm; and it did not veer in the least, as far as I could judge from the smoke; it had not been unusually sultry or warm for the end of March."
--A.R. Schmidt, Creighton Professor (not of meteorology), MWR article
Daily Weather Map 23 March 1913 12Z
Observational Data
23 March 1913 highs (MWR)
Hand-analysis of 23 March high temps
Evidence of eastward propagation of dry line
Also evidence of northward extent of warm front
COOP reports (courtesy NCDC)
High density (often 1 per county) of COOP reports with highs, lows, precip, prevailing wind, and comments for significant events.
Scans sometimes bad, tough to read cursive!
COOP reports (courtesy NCDC)
COOP storm report summary
D=Dust W=Wind H=Hail R=Rain
Regional Conditions
Hand-analysis of 13Z 23 March T/Td/Wind
Quality moisture in OK/TX, far from Omaha area (morning dewpoint only 33!)
Southerly flow and WAA has begun
*Note: fronts not invented yet in 1913!
Regional Conditions
Hand-analysis of 01Z 24 March T/Td/Wind
Cold front through Omaha area
Warm sector very tight to both dry line and warm front
Regional Conditions--est. 21Z map
OMA/LNK obs estimated
Observed rain in York, David City, Fremont, Albion from 21-23Z
Wind shifted to NW in Osceola at 2230Z
Fairbury/Bruning obs dust storm sometime during the day
Dust storm all day long in Western/Central Kansas
Regional Conditions--est. 23Z map
OMA/LNK obs estimated
RH jump in Lincoln from 53% to 78% from 2150Z to 2230Z; T/Td extrapolated from this
Low pressure minimum at 2345Z in Lincoln
Tornado observed SW of Lincoln just before 23Z--first of the day, eventually becomes Omaha tornado
Most major tornadoes will begin in the next hour
23 March 1913 descriptions
23 March 1913 descriptions
23 March 1913 descriptions
23 March 1913 descriptions
F3+ Tornado summary (Grazulis)
F3+ Tornado summary
Synoptic Conditions
Synoptic Conditions (Compo et al)
March 1913 SLP mean--strong high pressure in Atlantic
Summer-like, steady flow of moisture into Gulf Coast
Positive NAO signal
Cause?
Novarupta eruption 1912
Most prolific volcanic eruption in the 20th century
6 June 1912 in Alaska near Anchorage
Eruption continued until October
Spread across northern hemisphere
Cooled temperatures during the summer
Limited observational dataset of high-latitude volcanic eruptions favors a positive NAO for a few years after the event
http://www.ub.edu/gc/Documentos/Prohom_CHAPTER_5.pdf
Synoptic Conditions (Compo et al)
March 20-23 mean 900 mb specific humidity anomaly
Approaching 200% of average along Gulf Coast
Dry (and cold) around Omaha
Synoptic Conditions (Compo et al)
Deep 500 hPa trough approaches from the west at 00Z 23 March
Strong flow aloft, surface moisture advection northward
Trough likely too weak based on observed SLP vs. reanalysis SLP
Storm scale modeling
Initialized a 60 km North American WRF-ARW, with nests at 12 and 4 km from re-analysis
Attempted different initial times to try to find optimal forecast
Surprising level of accuracy
22 March 1913 18Z data initialized at 12Z to better match slow model data to real-world
23 Mar 1913 12Z 250 hPa
Jet stream likely too weak but flow pattern looks reasonable
23 Mar 1913 12Z 500 hPa
Strong SW flow at 500 hPa with shortwave in right place
23 Mar 1913 12Z 700 hPa
Green line is +6C at 700 hPa--evidence of cap that is borne out by real-world sequence of events
23 Mar 1913 12Z 850 hPa
23 Mar 1913 12Z 2m Dewpoint
Frontal position too far south compared to obs, but E-W orientation is correct
23 Mar 1913 12Z MSLP
Low pressure center is too far south and not deep enough
24 Mar 1913 00Z 250 hPa
Jet stream seems pretty reasonable
24 Mar 1913 00Z 500 hPa
Shortwave also seems quite reasonably depicted
24 Mar 1913 00Z 700 hPa
Cap has weakened considerably in Nebraska
24 Mar 1913 00Z 850 hPa
24 Mar 1913 00Z MSLP
Surface low is too far southwest and not deep enough. Convection mostly north of low
24 Mar 1913 00Z 2m Temps
Too far south and west, but dryline surge and related warmth are depicted well
24 Mar 1913 00Z 2m Dewpoint
Dryline surge again showed well, but not strong enough. Wind speeds also much too weak.
Diagnostic fields
24 Mar 1913 00Z CAPE
Pattern and magnitude seem reasonable, just needs to be shifted to the northeast
24 Mar 1913 00Z 0-1km SRH
Probably not high enough, given that surface winds were observed much stronger than the model
24 Mar 1913 00Z Radar
24 Mar 1913 00Z Max 10m wind
Far too weak--should have been in the 30-40 knot range in Kansas
24 Mar 1913 00Z Updraft Helicity
Some evidence of updraft rotation in convection, but far too weak. Convection mostly not in warm sector.
24 Mar 1913 00Z LLWS
Synthesis--Key findings
Anomalous moisture near the gulf coast was pulled northward by one of a series of strong shortwaves during a positive NAO that may have been influenced by a major volcanic eruption in the summer of 1912
Just enough capping existed to prevent warm sector convection until forcing arrived with strong surface low
Timing was perfect--moisture and low pressure center arrived in Eastern NE at peak heating under high-end wind shear conditions
Forcing at dryline/cold front intersection helped produce discrete cells before stronger frontal forcing dominated producing a derecho
Lessons and questions
Lessons and questions
Acknowledgments
Rich Ritz for assistance formatting 1913 observed weather data to be read by 2013 computer models
Jim Keane for his expertise on volcanoes and climate
Air Force Weather Agency for computing resources