A composite image showing a serial derecho as it travels across the Midwest. These are satellite water vapor images with lightning strikes overlaid. This storm produced widespread wind damage with winds of 80 to 100 mph in the most intense portions of the storm. Derecho is from the Spanish for "straight" and refers to the strong straight-line winds associated with these type of storms.

Regional radar image of derecho racing to the southeast across Kansas.

Aerial photograph geo-C25883793 of Texas coast following landfall of Hurricane Ike.

Aerial photograph geo-C25883805 of Texas coast following landfall of Hurricane Ike.

Aerial photograph geo-C25883831 of Texas coast following landfall of Hurricane Ike.

Aerial photograph geo-C25883869 of Texas coast following landfall of Hurricane Ike.

Radar display of frontal system with fairly intense precipitation extending across the Southeast United States.

Green flash flood warning box, yellow severe thunderstorm warning boxes, red tornado warnings (these red warning boxes are issued when rotation is indicated in the storm clouds) which coincided with the Bradford County tornado, darker yellow offshore marine warning.

Bats encountering supercell thunderstorm with hook echo indicative of tornado.

A north-south line of thunderstorms bisecting the southern Florida Peninsula.

Hurricane Humberto shortly after making landfall at High Island, Texas. The eye is still well-defined and rain-bands are well-defined. Although hitting shore as a minimal hurricane, it was one of the most rapidly intensifying hurricanes on record.

Part of a loop showing the evolution of Hurricane Lili on the Lake Charles radar .

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

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. This system spawned the devastating Joplin, Missouri, tornado.

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

Earliest northern hemisphere weather map produced by Weatehr 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.