I was reading SkyscraperCity (http://www.skyscrapercity.com/showthread.php?t=1672175) and found this very interesting.

Daytime Population

500,000+
Albuquerque, New Mexico 566,581
Atlanta, Georgia 687,251
Austin, Texas 911,073
Baltimore, Maryland 723,951
Boston, Massachusetts 844,309
Charlotte, North Carolina 835,219
Chicago, Illinois 2,880,923
Cleveland, Ohio 530,092
Columbus, Ohio 850,506
Dallas, Texas 1,430,898
Denver, Colorado 734,217
Detroit, Michigan 808,908
El Paso, Texas 635,959
Fort Worth, Texas 763,796
Fresno, California 522,211
Houston, Texas 2,645,327!
Indianapolis, Indiana 949,227
Jacksonville, Florida 887,380
Kansas City, Missouri 545,534
Las Vegas, Nevada 630,339
Los Angeles, California 3,942,579
Louisville, Kentucky 644,192
Memphis, Tennessee 771,573
Miami, Florida 605,034
Milwaukee, Wisconsin 620,609
Nashville, Tennessee 689,904
New York, New York 8,687,425
Oklahoma City, Oklahoma 658,914
Philadelphia, Pennsylvania 1,611,196
Phoenix, Arizona 1,582,418
Portland, Oregon 688,575
Sacramento, California 563,495
San Antonio, Texas 1,393,160
San Diego, California 1,449,880
San Francisco, California 951,627
San Jose, California 874,886
San Juan, Puerto Rico 511,974
Seattle, Washington 752,827
Tucson, Arizona 573,581
Washington, District of Columbia 1,046,036

current and traditional peer cities highlighted. OKC central city adds nearly 60,000 net each day. DC nearly doubles.

Over 100,000 but <500,000
Akron, Ohio 225,188
Alexandria, Virginia 144,393
Anchorage, Alaska 293,809
Arlington, Virginia 249,979
Birmingham, Alabama 310,477
Cambridge, Massachusetts 162,367!
Chandler, Arizona 210, 423
Chesapeake, Virginia 202,603
Cincinnati, Ohio 413,302
Dayton, Ohio 185,079
Gainesville, Florida 163,550
Hampton, Virginia 139,689
Hialeah, Florida 202,966
Honolulu, Hawaii 446,366
Huntsville, Alabama 222,012
Jackson, Mississippi 213,140
Knoxville, Tennessee 264,812
Little Rock, Arkansas 261,048
Madison, Wisconsin 292,502
Mesa, Arizona 408,028
Miami Beach, Florida 101,440
Minneapolis, Minnesota 483,229
Mobile, Alabama 238,772
Montgomery, Alabama 242,221
New Orleans, Louisiana 358,772
Newport News, Virginia 198,891
Norfolk, Virginia 309,689
Oakland, California 406,239
Omaha, Nebraska 492,509
Orlando, Florida 406,716!
Paradise, Nevada 370,663
Pittsburgh, Pennsylvania 457,079
Plano, Texas 283,181
Portsmouth, Virginia 108,212
Providence, Rhode Island 217,292
Provo, Utah 120,009
Richardson, Texas 133,630
Richmond, Virginia 268,594
Roanoke, Virginia 124,032
Rochester, Minnesota 132,223
Round Rock, Texas 102,593
Saint Louis, Missouri 433,778
Saint Paul, Minnesota 321,554
Salt Lake City, Utah 332,002
Scottsdale, Arizona 278,218
Tampa, Florida 494,497!
Tempe, Arizona 239,861
Toledo, Ohio 305,805
Tulsa, Oklahoma 471,984
Tuscaloosa, Alabama 109,210
Tyler, Texas 123,638
Virginia Beach, Virginia 401,154
Waco, Texas 149,218
West Valley City, Utah 117,178
Wichita, Kansas 392,016
Wichita Falls, Texas 113,522