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
thumb|left|The supercell that produced an F3 tornado in Cheyenne, Wyoming, as seen on WSR-74S imagery
There are two types in the WSR-74 series, which are almost identical except for operating frequency. 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, and has a generally shorter maximum effective range.
The WSR-74C uses a wavelength of 5.4 cm. 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
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. In the early 1970s, Enterprise Electronics Corporation (EEC), based out of Enterprise, Alabama won the contract to design, manufacture, test, and deliver the entire WSR-74 radar network (both C and S-Band versions).
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. NWS Lubbock received the first WSR-74C in August 1973 following widespread attention from the F5 Lubbock tornado of 1970.
128 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.
The last WSR-74C used by the NWS was located in Williston, ND, before being decommissioned at the end of 2012.
No WSR-74S's are in the NWS inventory today, having been replaced by the WSR-88D, but some of these radars are in commercial use.
Radar sites in the US
thumb|upright=2|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:
{|class="wikitable" align="left" width="45%"
! 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)<br>
Was atop the WSFO building at 3420 Norman Berry Drive
|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)
|Early 1980s
|June 10, 1998
|-
|Cheyenne, WY (CYS)
|September 15, 1976
|April 24, 1996
|-
|Cleveland, OH (CLE)
|August 4, 1976<BR><BR>
Replaced a WSR-3.
|November 15, 1995
|-
|Columbia, MO (COU)
|November 9, 1977<BR><BR>
Replaced a WSR-3.
|June 19, 1996
|-
|Columbia, SC (CAE)
|January 26, 1976
Replaced a WSR-1.
|October 25, 1995
|-
|Columbus, GA (CSG)
|April 2, 1979
|April 3, 1996
|-
|Columbus, OH (CMH)
|June 9, 1977<BR><BR>
Replaced a WSR-3.
|December 1, 1995
|-
|Concordia, KS (CNK)
|February 18, 1977<BR><BR>
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?<!-- planned -->
|-
|Fort Smith, AR (FSM)
|November 25, 1975<BR><BR>
Replaced a WSR-3.
|July 7, 1998
|-
|Fort Wayne, IN (FWA)
|March 12, 1976<BR><BR>
Replaced a WSR-3.
|July 8, 1998
|-
|Goodland, KS (GLD)
|June 6, 1978<BR><BR>
Replaced a WSR-3.
|October 25, 1995
|-
|Harrisburg, PA (HAR)
Atop the Federal Building
|June 28, 1977
|January 12, 1996
|-
|Hartford, CT (BDL)
|April 1977
|November 2, 1995
|-
|Houghton Lake, MI (HTL)
|February 1, 1977
|December 9, 1996
|-
|Huntsville, AL (HSV)<br>
(Doppler capability after July 1991)
|1977.<br>
Replaced a WSR-3.
|December 15, 1999?<!-- planned --><br>
Now the ARMOR radar, still used by Local Media/NWS.
|-
|Indianapolis, IN (IND)
|September 28, 1977
|February 28, 1996
|-
|Las Vegas, NV (LAS)
|1976
|September 1, 1995
|-
|Los Angeles, CA (LAX)<br>
On top of the Federal Building in Westwood to this day.
|
|May 15, 1995
|-
|Louisville, KY (SDF)
|April or May 1978
|July 19, 1994
|-
|Lubbock, TX (LBB)
|August 1973
|April 3, 1996
|-
|Macon, GA (MCN)
|April 18, 1977
|April 3, 1996
|-
|Madison, WI (MSN)<br>
At Madison Airport.
|June 19, 1979 <BR>
Replaced a WSR-3
|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)<br>
(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<!-- in North Omaha, replacing a WSR-57? -->
|July 10, 1996<!-- The office closed in 1994 -->
|-
|Paducah, KY (PAH)<br>
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<!-- now used at the same location by a cloud-seeding company, according to the tour I took at NWS SJT -->
|-
|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
|-
|}
{| class="wikitable" align="right" width="45%"
! 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)<br>
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<BR><BR>Replaced a WSR-57.
|November 9, 1995
|-
|Fargo, ND (FAR)
|February 1, 1978<BR><BR>Was a WSR-74C from Oct. 9, 1976 to Nov. 27, 1977
|November 27, 1996
|-
|Jackson, KY (JKL)<BR>WSR-74S providing local coverage
|April 1, 1981
|July 1, 1997
|-
|Key West, FL (EYW)
|May 9, 1983<br>
Replaced a WSR-57.
|October 20, 1998
|-
|Longview, TX (GGG)
|March 1, 1978
|March 14, 1996
|-
|Marseilles, IL (MMO)<br>
(Doppler capability)
|November 1, 1974.<br>
Replaced a WSR-57 at Chicago<!-- the WSR-57 might have already been at Marseilles -->.
|January 19, 1996
|-
|Memphis, TN (MEG)<br>
At East Memphis/Agricenter site
|January 1986.<br>
Replaced a WSR-57.
|June 21, 1995
|-
|Patuxent River, MD (NHK)<br>
At Patuxent River NAS
|Early 1980s.<br>
Replaced a WSR-57 at Washington, DC<!-- according to http://www.stormtrack.org/forum/viewtopic.php?t=10344 -->.
|November 17, 1995
|-
|Portland, ME (PWM)
|March 5, 1985 <BR><BR>Replaced a WSR-57.
|September 13, 1995
|-
|San Juan, Puerto Rico (SJU)<br>
WSR-74S providing local coverage
|
|February 26, 1999
|-
|Volens<!-- can't find it? look at http://weather.gladstonefamily.net/site/KVQN -->, VA (VQN/7VM)
|April 12, 1977
|December 1, 1995
|-
|West Palm Beach, FL (PBI)<br>
WSR-74S providing local coverage. Became part of the national network after the WSR-57 at Miami was destroyed in Hurricane Andrew.
|December 17, 1980
|October 13, 1995
|-
|}
See also
References
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