North Central River Forecast Center



WSR-88D Z/R Relationship Table

This table shows WSR-88D Z/R relationships for sites used in the North Central River Forecast Center Multisensor Precipitation radar mosaic. A Z/R relationship is an empirical formula used to estimate rainfall rates from reflectivity signal strength. Parameters that can be varied at each radar site are shown in red. Max Precip Rate is an adjustable parameter which limits overestimation from hail contamination, ground clutter, etc. The Bias Correction Factor shows three elements: the duration (in hours) used to calculate the bias, the bias (in red), and the number of non-zero gage/radar pairs used to calculate the bias for that duration.

Most stratiform rain has a reflectivity signal strength of 20-40dBZ with peaks to 45dBZ, but rarely anything higher (that isn't "brightbanding"). For more information, authorization, instructions, and recommendations regarding Z/R relationships, see the Radar Operations Center's page.

Radar SiteRadar IdWFO IdTime Reported (UTC) Z/R FormulaMax Precip
Rate(in/hr)
Z/R TypeBias Correction Factor
Aberdeen, SDABRABR28 Feb 2015 13:00Z=130R24.09Cool Season (East)
Stratiform Z/R
720-hr:0.96 #50
No Bias
Bethune 10S, SKXBEWWG28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.27 #18
Under-estimation
Bismarck, NDBISBIS28 Feb 2015 13:00Z=200R1.67.87Marshall/Palmer
Stratiform Z/R
720-hr:1.40 #12
Under-estimation
Chicago, ILLOTLOT28 Feb 2015 13:00Z=130R23.44Cool Season (East)
Stratiform Z/R
168-hr:1.33 #27
Under-estimation
Des Moines, IADMXDMX28 Feb 2015 13:00Z=130R25.91Cool Season (East)
Stratiform Z/R
168-hr:1.27 #39
Under-estimation
Detroit, MIDTXDTX28 Feb 2015 13:00Z=130R24.53Cool Season (East)
Stratiform Z/R
720-hr:1.54 #338
Under-estimation
Dryden 6NNE, ONXDRWTO28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.61 #13
Under-estimation
Duluth, MNDLHDLH28 Feb 2015 13:00Z=130R24.09Cool Season (East)
Stratiform Z/R
720-hr:1.07 #132
Under-estimation
Exeter 5NNE, ONWSOWTO28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.64 #67
Under-estimation
Foxwarren 4NE, MBXFWWWG28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.00 #24
No Bias
Gaylord/NC Lwr MIAPXAPX28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.29 #176
Under-estimation
Grand Rapids, MIGRRGRR28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
168-hr:1.18 #11
Under-estimation
Green Bay, WIGRBGRB28 Feb 2015 13:00Z=130R24.09Cool Season (East)
Stratiform Z/R
720-hr:1.28 #214
Under-estimation
Indianapolis, ININDIND28 Feb 2015 13:00Z=200R1.62.95Marshall/Palmer
Stratiform Z/R
720-hr:1.41 #210
Under-estimation
La Crosse, WIARXARX28 Feb 2015 13:00Z=130R23.00Cool Season (East)
Stratiform Z/R
168-hr:1.83 #19
Under-estimation
Lasseteer Lake, ONXNIWTO28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.84 #20
Under-estimation
Lincoln/Ctl IllinoisILXILX28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
168-hr:1.95 #31
Under-estimation
Marquette, MIMQTMQT28 Feb 2015 13:00Z=130R24.09Cool Season (East)
Stratiform Z/R
720-hr:1.33 #90
Under-estimation
Mayville/Grand ForksMVXFGF28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.20 #29
Under-estimation
Milwaukee, WIMKXMKX28 Feb 2015 13:00Z=130R23.94Cool Season (East)
Stratiform Z/R
168-hr:1.37 #16
Under-estimation
Minneapolis, MNMPXMPX28 Feb 2015 13:00Z=130R23.25Cool Season (East)
Stratiform Z/R
720-hr:0.97 #159
No Bias
Minot AFB, NDMBXBIS28 Feb 2015 13:00Z=200R1.67.87Marshall/Palmer
Stratiform Z/R
720-hr:1.23 #23
Under-estimation
Montreal River, ONWGJWTO28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.69 #34
Under-estimation
North Webster/Nrn INIWXIWX28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.51 #407
Under-estimation
Omaha/Valley, NEOAXOAX28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.13 #185
Under-estimation
Owensville, INVWXPAH28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
168-hr:1.08 #32
Under-estimation
Paducah, KYPAHPAH28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
168-hr:1.23 #60
Under-estimation
Pleasant Hill, MOEAXEAX28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
168-hr:0.98 #29
No Bias
Quad Cities, IA/ILDVNDVN28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
168-hr:2.12 #38
Under-estimation
Sioux Falls, SDFSDFSD28 Feb 2015 13:00Z=130R24.09Cool Season (East)
Stratiform Z/R
720-hr:1.21 #120
Under-estimation
Springfield, MOSGFSGF28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
168-hr:1.72 #13
Under-estimation
St. Louis, MOLSXLSX28 Feb 2015 13:00Z=200R1.66.00Marshall/Palmer
Stratiform Z/R
168-hr:1.77 #71
Under-estimation
Woodlands 6SW, MBXWLWWG28 Feb 2015 13:00Z=200R1.64.09Marshall/Palmer
Stratiform Z/R
720-hr:1.38 #15
Under-estimation


Generated by get_ZR script Sat 02/28/2015 13:35 UTC