Comparison of Storm Relative Velocity display and Composite Reflectivity display . The change from green to red west of Goodman indicates rotation and is an indicator of tornadic activity. In fact, a large tornado struck the Goodman area at this time.

A special marine warning (deep yellow box north of Key West) for heavy thunderstorms.

Integrated rainfall totals from Tropical Storm Allison. Note white areas indicating over 25 inches of rain at Houston and Beaumont.

National Weather Service Quad Cities WSFO

National Weather Service Quad Cities WSFO Doppler Radar installation

National Weather Service Quad Cities WSFO

A zig-zag frontal boundary with much associated severe weather. See image wea01878.

Tornado warnings in NE Arkansas from the Memphis National Weather Service Forecast Office.

Tornado warnings (red polygons) on NWS Doppler radar from Nashville National Weather Service Forecast Office.

A razor sharp frontal boundary. Compare to image wea01877.

Supercells lined up on frontal boundary spawning tornadic activity

Doppler radar composite showing tornado warnings in NW Arkansas and south central Missouri.

Donut shaped precipitation pattern surrounding Pontiac and Detroit. Perhaps a Halloween trick.

A classic cyclone with trailing front. Low pressure center located over Missouri.

Classic comma-shaped system with tornadoes forming ESE of low-pressure center which is over western Kansas.

Tornado warnings issues by Memphis Weather Service Forecast Office superimposed on Doppler radar base reflectivity.

Earliest northern hemisphere weather map produced by Weather Bureau cooperatively with other nations.

Early diagram showing the evolution of cyclones and the polar front theory first advanced by J. Bjerknes. In: "Life Cycle of Cyclones and the Polar Front Theory of Atmospheric Circulation," p. 3, Geofysiske Publikationer, Vol III, No. 1, 1922.

The life cycle of cyclones as theorized by J. Bjerknes in: "Life Cycle of Cyclones and the Polar Front Theory of Atmospheric Circulation," p. 5, Geofysiske Publikationer, Vol III, No. 1, 1922.

The two kinds of occlusions seen in cross-section as shown by J. Bjerknes in: "Life Cycle of Cyclones and the Polar Front Theory of Atmospheric Circulation," p. 8, Geofysiske Publikationer, Vol III, No. 1, 1922.

The polar front through a series of cyclones as shown by J. Bjerknes in: "Life Cycle of Cyclones and the Polar Front Theory of Atmospheric Circulation," p. 11, Geofysiske Publikationer, Vol III, No. 1, 1922.

Early Weather Bureau logo.

The snow brought joy to some. The "Knickerbocker" snowstorm. 97 were killed in this storm and over 200 injured, the majority in the Knicker bocker Theater.

The snow was a trifle too much for the dinky sweepers. The "Knickerbocker" snowstorm. 97 were killed in this storm and over 200 injured, the majority in the Knickerbocker Theater.

A police officer directs traffic during the "Knickerbocker" snowstorm. 97 were killed in this storm and over 200 injured, the majority in the Knicker bocker Theater.

In front of the Knickerbocker Theater immediately after it collapsed. Handwritten note below indicates that it was probably the following night. 96 were killed and 125 injured in the collapse of the theater. One other man froze to death in the storm.

Crowds watching the work of rescue at the Knickerbocker Theater. 96 were killed and 125 injured in the collapse of the theater. One other man froze to death in the storm.

View of the interior of the Knickerbocker Theater after the last body had been removed. 96 were killed and 125 injured in the collapse of the theater. One other man froze to death in the storm.

Outside walls of Knickerbocker Theater following collapse of interior. 96 were killed and 125 injured in the collapse of the theater. One other man froze to death in the storm.

Sketch of Knickerbocker Theater prior to collapse. Hand-written note below caption says, "Wholly inaccurate picture. Compare photograph on preceding page. " 96 were killed and 125 injured in the collapse of the theater. One other man froze to death in the storm.

Cover of "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926. Library Call No. M 1270 G646.

Rescuing a motor car from burial in the snow on a Long Island Highway. One kind of horsepower providing assistance to another kind. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926. Library Call No. M 1270 G646.

Pennsylvania's plan is to clear a generous width. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926. Library Call No. M 1270 G646.

Clearing snow from 5th Avenue, New York City. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926. Library Call No. M 1270 G646.

An example of slopes in an area of high winds which can cause drifting. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926. Library Call No. M 1270 G646.

Drifts like these increase the cost of snow removal. Prevention is the economical way. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926. Library Call No. M 1270 G646.

Snow fence, properly placed, holds back the drifts from the highway, as shown here. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926. Library Call No. M 1270 G646.

One of the drift-breeding locations which led Pennsylvania to invest in a million feet of snow fence. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926. Library Call No. M 1270 G646.

Philadelphia Wilmington bus stalled in the evening snow. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926.

Fifth Avenue bus in difficulties. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926.

When the wheels stop, the revenue stops. Contractors find it pays to equip trucks with snow plows and keep the wheels moving. Note open cab and chains on rear tires. In: "Handbook of Snow Removal" by Good Roads Machinery, Inc. 1926. Library Call No. M 1270 G646.

"Snow removal in New York City" in 'The Municipal Engineers Journal', Vol. 1, No . 5, November 1915. Street nearly impassable - snow piled on sides. Library Call No. M 1270 F 419.

"Snow removal in New York City" in 'The Municipal Engineers Journal', Vol. 1, No . 5, November 1915. Snow piled in center of street - an improvement over side piling where it can be used. Library Call No. M 1270 F 419.

"Snow removal in New York City" in 'The Municipal Engineers Journal', Vol. 1, No . 5, November 1915. Shortening truck haul by snow disposal in large sewers. Library Call No. M 1270 F 419.

"Snow removal in New York City" in 'The Municipal Engineers Journal', Vol. 1, No . 5, November 1915. Drag scraper for short hauls and disposal in sewers. Library Call No. M 1270 F 419.

"Snow removal in New York City" in 'The Municipal Engineers Journal', Vol. 1, No . 5, November 1915. Testing pan scraper capacity. Using bran instead of snow. Library Call No. M 1270 F 419.

"Snow removal in New York City" in 'The Municipal Engineers Journal', Vol. 1, No . 5, November 1915. Panning snow into sewers, using hand labor. Library Call No. M 1270 F 419.

"Snow removal in New York City" in 'The Municipal Engineers Journal', Vol. 1, No . 5, November 1915. Commercial trucks with snow plows attached. Library Call No. M 1270 F 419.

"Snow removal in New York City" in 'The Municipal Engineers Journal', Vol. 1, No . 5, November 1915. Easter Sunday morning (1915) on Fifth Avenue, three hours after snow storm ceased - street cleared before noon. Library Call No. M 1270 F 419.

"Snow removal in New York City" in 'The Municipal Engineers Journal', Vol. 1, No . 5, November 1915. Regulator for mixing hydrant water and compacted snow. Library Call No. M 1270 F 419.