WSR-74

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WSR-74C radar from Central Illinois WFO

WSR-74 radars were Weather Surveillance Radars designed in 1974 for the National Weather Service. They were added to the existing network of the WSR-57 model to improve forecasts and severe weather warnings. Some have been sold to other countries like Australia, Greece, and Pakistan.

Radar properties[edit]

There are two types in the WSR-74 series, which are almost identical except for operating frequency.[1] The WSR-74C (used for local warnings) operates in the C band, and the WSR-74S (used in the national network) operates in the S band (like the WSR-57 and the current WSR-88D). S band frequencies are better suited because they are not attenuated significantly in heavy rain while the C Band is strongly attenuated.

The WSR-74C uses a wavelength of 5.4 cm.[2] It also has a dish diameter of 8 feet, and a maximum range of 579 km (313 nm) as it was used only for reflectivities (see Doppler dilemma).

History[edit]

The WSR-57 network was very spread out, with 66 radars to cover the entire country. There was little to no overlap in case one of these vacuum-tube radars went down for maintenance. The WSR-74 was introduced as a "gap filler", as well as an updated radar that, among other things, was transistor-based.[3]

WSR-74C radars were generally local-use radars that didn't operate unless severe weather was expected, while WSR-74S radars were generally used to replace WSR-57 radars in the national weather surveillance network. When a network radar went down, a nearby local radar might have to supply updates like a network radar.[4] NWS Lubbock received the first WSR-74C in August 1973 following widespread attention from the Lubbock F5 tornado of 1970.[5]

128[6] of the WSR-57 and WSR-74 model radars were spread across the country as the National Weather Service's radar network until the 1990s. They were gradually replaced by the WSR-88D model (Weather Surveillance Radar - 1988, Doppler), constituting the NEXRAD network. The WSR-74 had served the NWS for two decades.

Twelve WSR-74Cs still have not been decommissioned and, of those, seven remain in active use today. The last WSR-74C used by the NWS was located in Williston, ND, before being decommissioned at the end of 2012.[7] No WSR-74Ss are in the NWS inventory today, having been replaced by the WSR-88D. Some of these radars are in commercial use.

Radar sites in the US[edit]

Circles showing the coverage of the WSR-57 and WSR-74 radars. Note the large gap over the western United States.

WSR-74 sites include the following two categories:[8][9]

WSR-74C Site Commissioned Decommissioned
Abilene, TX (ABI) August 27, 1977 April 30, 1997
Akron, OH (CAK) June 1, 1977 November 15, 1995
Albany, NY (ALB) July 27, 1977 November 2, 1995
Alpena, MI (APN) June 8, 1977 December 9, 1996
Atlanta, GA (ATL)

On a building between Hartsfield and downtown to this day.

October 20, 1976 February 1, 1996
Augusta, GA (AGS) July 1, 1976 July 30, 1996
Austin, TX (AUS) April 9, 1976 October 13, 1995
Baton Rouge, LA (BTR) October 20, 1978 May 14, 1996
Beckley, WV (BKW) November 1, 1977 January 12, 1996
Billings, MT (BIL) April 18, 1978 May 30, 1996
Bismarck, ND (BIS) October 5, 1978 February 28, 1996
Burlington, VT (BTV) Late 1977 January 29, 1998
Charlotte, NC (CLT) February 28, 1978 September 17, 1996
Chattanooga, TN (CHA) June 10, 1998
Cheyenne, WY (CYS) September 15, 1976 April 24, 1996
Cleveland, OH (CLE) August 4, 1976

Replaced a WSR-3.

November 15, 1995
Columbia, MO (COU) Novbember 9, 1977

Replaced a WSR-3.

June 19, 1996
Columbia, SC (CAE) January 26, 1976

JReplaced a WSR-1.

October 25, 1995
Columbus, GA (CSG) April 2, 1979 April 3, 1996
Columbus, OH (CMH) June 9, 1977

Replaced a WSR-3.

December 1, 1995
Concordia, KS (CNK) February 18, 1977

Replaced a WSR-3.

November 9, 1995
Corpus Christi, TX (CRP) February 1, 1976 March 10, 1997
Duluth, MN (DLH) 1977 March 25, 1997
Erie, PA (ERI) August 30, 1977 January 15, 2000?
Fort Smith, AR (FSM) November 25, 1975

Replaced a WSR-3.

July 7, 1998
Fort Wayne, IN (FWA) March 12, 1976

Replaced a WSR-3.

July 8, 1998
Goodland, KS (GLD) June 6, 1978

Replaced a WSR-3.

October 25, 1995
Harrisburg, PA (HAR) June 28, 1977 January 12, 1996
Hartford, CT (BDL) April 1977 November 2, 1995
Houghton Lake, MI (HTL) December 9, 1996
Huntsville, AL (HSV)

(Doppler capability after July 1991)

1977.

Replaced a WSR-3.

December 15, 1999?

Now the ARMOR radar.

Indianapolis, IN (IND) September 28, 1977 February 28, 1996
Las Vegas, NV (LAS) September 1, 1995
Los Angeles, CA (LAX)

On top of the Federal Building in Westwood to this day.

May 15, 1995
Louisville, KY (SDF) July 19, 1994
Lubbock, TX (LBB) August 1973 April 3, 1996
Macon, GA (MCN) April 18, 1977 April 3, 1996
Madison, WI (MSN)

At Madison Airport.

1972 May 7, 1996
Marquette, MI (MQT) July 16, 1996
Meridian, MS (MEI) November 2, 1976 December 26, 1996
Mobile, AL (MOB) October 12, 1995
Moline, IL (MLI) August 30, 1977 January 19, 1996
Montgomery, AL (MGM)

(Doppler capability after 1982)

1977 June 4, 1996
Muskegon, MI (MKG) March 25, 1976 August 13, 1996
Norfolk, NE (OFK) May 14, 1976 March 25, 1997
North Platte, NE (LBF) November 27, 1996
Omaha, NE (OVN) 1977 July 10, 1996
Paducah, KY (PAH)

At the Paducah Airport.

1984 February 23, 1996
Phoenix, AZ (PHX) August 15, 1994
Portland, OR (PDX) January 30, 1996
Raleigh, NC (RDU) May 19, 1977 December 22, 1995
Rapid City, SD (RAP) November 4, 1996
Rochester, MN (RST) April 1976 January 9, 1997
San Angelo, TX (SJT) October 1977 April 22, 1997
Savannah, GA (SAV) November 15, 1982 February 11, 1997
Shreveport, LA (SHV) June 1976 June 5, 1996
Sioux Falls, SD (FSD) 1976 October 4, 1996
South Bend, IN (SBN) October 22, 1982 July 8, 1998
Springfield, IL (SPI) October 16, 1980 July 30, 1996
Topeka, KS (TOP) 1976 November 2, 1995
Tucson, AZ (TUS) January 1983 March 14, 1996
Tulsa, OK (TUL) March 12, 1976 April 5, 1995
Tupelo, MS (TUP) April 1, 1983 December 6, 1995
Waco, TX (ACT) November 8, 1976 September 13, 1995
Waterloo, IA (ALO) November 19, 1976 January 17, 1997
Wichita Falls, TX (SPS) February 5, 1977 December 26, 1996
Williston, ND (ISN) February 21, 1978 December 31, 2012
Worcester, MA (ORH) July 2, 1976 April 5, 1995
WSR-74S Site Commissioned Decommissioned
Alliance, NE (AIA) June 10, 1977 January 17, 1997
Binghamton, NY (BGM) March 8, 1978 September 26, 1995
Charleston, WV (CRW)

WSR-74S providing local coverage

May 16, 1977 January 12, 1996
Chatham, MA (CHH) May 6, 1983 April 5, 1995
Detroit, MI (DTW) March 9, 1984

Replaced a WSR-57.
November 9, 1995
Fargo, ND (FAR) February 1, 1978

Was a WSR-74C from Oct. 9, 1976 to Nov. 27, 1977
November 27, 1996
Jackson, KY (JKL)
WSR-74S providing local coverage
April 1, 1981 July 1, 1997
Key West, FL (EYW) 1980.

Replaced a WSR-57.

October 20, 1998
Longview, TX (GGG) March 1, 1978 March 14, 1996
Marseilles, IL (MMO)

(Doppler capability)

November 1, 1974.

Replaced a WSR-57 at Chicago.

January 19, 1996
Memphis, TN (MEG)

At East Memphis/Agricenter site

January 1986.

Replaced a WSR-57.

June 21, 1995
Monett, MO (UMN) March 16, 1971

Replaced a WSR-57
February 1, 1996
Patuxent River, MD (NHK)

At Patuxent River NAS

Early 1980s.

Replaced a WSR-57 at Washington, DC.

November 17, 1995
Portland, ME (PWM) March 5, 1985

Replaced a WSR-57.
September 13, 1995
San Juan, Puerto Rico (SJU)

WSR-74S providing local coverage

February 26, 1999
Volens, VA (VQN) April 12, 1977 December 1, 1995
West Palm Beach, FL (PBI)

WSR-74S providing local coverage

October 13, 1995


See also[edit]

References[edit]

  1. ^ http://www.its.bldrdoc.gov/pub/oprad/sect7.pdf
  2. ^ Paul Sirvatka. "WSR - Weather Surveillance Radar." Radar. College of DuPage. 4 Apr. 2006 <http://weather.cod.edu/sirvatka/radar.html>.
  3. ^ Roger C. Whiton, et al. "History of Operational Use of Weather Radar by U.S. Weather Services. Part I: The Pre-NEXRAD Era." Weather and Forecasting: Vol. 13, No. 2, pp. 219–243. 19 Feb. 1998. American Meteorological Society. 5 Apr. 2006 <http://ams.allenpress.com/amsonline/?request=get-document&doi=10.1175%2F1520-0434(1998)013%3C0219:HOOUOW%3E2.0.CO%3B2>.
  4. ^ Stormtrack.org Forum 9498
  5. ^ NWS Lubbock Office History
  6. ^ http://sysu1.wsicorp.com/unidata/intro.html
  7. ^ http://m.willistonherald.com/news/weather-radar-shutdown-imminent/article_c4780e20-6eba-554f-99f0-c2326dd5a0c8.html?mode=jqm
  8. ^ NWS Modernization Committee. "Toward a New National Weather Service - Assessment of NEXRAD Coverage and Associated Weather Services".
  9. ^ Stormtrack.org Forum 10344