Site ID: 510 Lat. 34.6810 USA Arkansas
River: Mississippi Long. -90.5699
Site name: Helena Contributing area: 2406269 km2 Ratio to Comparison Station: 85.21
Latest measurement: 18-Jul-10 Mean annual runoff: 13 mm (2003-2009)
Hydrologic status: 2 Normal flow Total runoff this year (2010): 9.7 mm
Latest M/C ratio: 1.41 Seven day total: 0.3 mm
Estimated current discharge: 1237 m3/sec Percent of mean 7-day total: 125.5 % (today's value compared to mean for same period, 2003-2009)
5 yr recurrence flood: 3288 m3/sec (from Log Pearson III analysis)
Status Codes:  1 = Low flow or ice, 2 = Normal flow, 3 = Flood, 4 = Major Flood 3445 m3/sec (from Gumbel Extreme Value analysis)
Comparison Station Information:  Boluo (2186950)           Contributing Area:   sq mi 28239 sq km
(Data from this gaging station are used for the calibration to discharge, with an adjustment for different contributing areas)
Notes: Final calibration to discharge has not yet been accomplished.
Discharge and runoff, based on satellite remote sensing (NASA AMSR-E data)
(For U.S, sites, nearby ground station discharge may also be shown)
Annual  Monthly Total Runoff (mm), computed from above satellite-based discharge data
Runoff
(mm) Jan Feb Mar April May June July Aug Sept Oct Nov Dec
4 2002 no data no data no data no data no data no data no data 0.7 0.8 0.7 0.8 0.8
12 2003 0.8 0.7 1.8 1.2 1.5 1.4 1.1 0.9 0.7 0.7 0.7 1.0
13 2004 1.0 0.9 1.2 1.0 1.2 1.4 1.2 1.0 1.1 0.8 0.9 1.1
12 2005 1.6 1.3 1.4 1.5 1.0 0.9 0.1 0.8 0.9 0.6 0.8 0.8
9 2006 0.6 0.7 1.0 0.9 1.0 0.9 1.0 0.8 0.7 0.9 0.0 0.0
13 2007 1.2 0.9 1.4 1.4 1.2 1.1 1.0 1.1 0.9 0.7 0.6 0.9
17 2008 0.9 1.0 1.8 3.8 2.0 1.6 1.5 1.1 0.9 0.7 0.7 0.8
14 2009 1.2 0.8 1.0 1.5 2.1 1.6 1.0 1.1 0.8 0.8 1.3 1.2
10 2010 0.9 1.2 1.3 1.8 2.3 1.4 0.9 0.0 0.0 0.0 0.0 0.0
Mean Annual Runoff (mm): 13 Standard Deviation: 6.4
Trend in Annual Runoff (slope):  -73
Discharge is estimated via a rating equation directly from the remote sensing data (M/C ratio) shown below.
Green line records upwelling microwave emission from within 5 km radius of a calbration land target. 
Explanation:   Blue line is emission from within 5 km radius of the measurement target centered over the river.
Brown line is their ratio (M/C; "HR" in Brakenridge et al 2007; scale on right) and is used to estimate river discharge via a rating equation.
Rating equations are being developed and applied on an individual basis using available ground-based discharge information.
GoogleEarth View of Measurement Site
Return
Estimated
Disharge
Data
Date m3/sec
22-Jul-02 1017
23-Jul-02 1017
24-Jul-02 1067
25-Jul-02 1135
26-Jul-02 1092
27-Jul-02 1089
28-Jul-02 1144
29-Jul-02 1136
30-Jul-02 1046
31-Jul-02 1037
1-Aug-02 955
2-Aug-02 896
3-Aug-02
4-Aug-02
5-Aug-02
6-Aug-02
7-Aug-02
8-Aug-02
9-Aug-02
10-Aug-02 1192
11-Aug-02 1008
12-Aug-02 939
13-Aug-02 896
14-Aug-02 811
15-Aug-02 735
16-Aug-02 705
17-Aug-02 548
18-Aug-02 441
19-Aug-02 582
20-Aug-02 708
21-Aug-02 1022
22-Aug-02 892
23-Aug-02 882
24-Aug-02 806
25-Aug-02 641
26-Aug-02 791
27-Aug-02 909
28-Aug-02 803
29-Aug-02 776
30-Aug-02 727
31-Aug-02 767
1-Sep-02 764
2-Sep-02 838
3-Sep-02 905
4-Sep-02 1029
5-Sep-02 993
6-Sep-02 960
7-Sep-02 1010
8-Sep-02 1023
9-Sep-02 1046
10-Sep-02 1152
11-Sep-02 971
12-Sep-02 932
13-Sep-02 787
14-Sep-02 787
15-Sep-02 808
16-Sep-02 637
17-Sep-02
18-Sep-02
19-Sep-02
20-Sep-02
21-Sep-02 1157
22-Sep-02 1118
23-Sep-02 1058
24-Sep-02 976
25-Sep-02 919
26-Sep-02 856
27-Sep-02 531
28-Sep-02 592
29-Sep-02 705
30-Sep-02 729
1-Oct-02 863
2-Oct-02 880
3-Oct-02 873
4-Oct-02 940
5-Oct-02 975
6-Oct-02 1168
7-Oct-02 1072
8-Oct-02 527
9-Oct-02 569
10-Oct-02 569
11-Oct-02 164
12-Oct-02 309
13-Oct-02 243
14-Oct-02 210
15-Oct-02 489
16-Oct-02 630
17-Oct-02 522
18-Oct-02 678
19-Oct-02 634
20-Oct-02 453
21-Oct-02 427
22-Oct-02 556
23-Oct-02 595
24-Oct-02 675
25-Oct-02 715
26-Oct-02 893
27-Oct-02 819
28-Oct-02 806
29-Oct-02 658
30-Oct-02 694
31-Oct-02 669
1-Nov-02 578
2-Nov-02 488
3-Nov-02 602
4-Nov-02 534
5-Nov-02 604
6-Nov-02 579
7-Nov-02 834
8-Nov-02 699
9-Nov-02 732
10-Nov-02 705
11-Nov-02 999
12-Nov-02 1130
13-Nov-02 1166
14-Nov-02 1397
15-Nov-02 895
16-Nov-02 652
17-Nov-02 681
18-Nov-02 654
19-Nov-02 595
20-Nov-02 718
21-Nov-02 683
22-Nov-02 682
23-Nov-02 658
24-Nov-02 589
25-Nov-02 610
26-Nov-02 641
27-Nov-02 789
28-Nov-02 859
29-Nov-02 892
30-Nov-02 824
1-Dec-02 485
2-Dec-02 523
3-Dec-02 434
4-Dec-02 496
5-Dec-02 518
6-Dec-02 423
7-Dec-02 454
8-Dec-02 381
9-Dec-02 522
10-Dec-02 659
11-Dec-02 808
12-Dec-02 805
13-Dec-02 814
14-Dec-02 627
15-Dec-02 587
16-Dec-02 508
17-Dec-02 459
18-Dec-02 706
19-Dec-02 780
20-Dec-02 822
21-Dec-02 788
22-Dec-02 757
23-Dec-02 934
24-Dec-02 1318
25-Dec-02 616
26-Dec-02 759
27-Dec-02 672
28-Dec-02 672
29-Dec-02 966
30-Dec-02 1064
31-Dec-02 1049
1-Jan-03 682
2-Jan-03 907
3-Jan-03 858
4-Jan-03 844
5-Jan-03 892
6-Jan-03 1089
7-Jan-03 1036
8-Jan-03 919
9-Jan-03 987
10-Jan-03 1004
11-Jan-03 1033
12-Jan-03 1114
13-Jan-03 1046
14-Jan-03 998
15-Jan-03 843
16-Jan-03 810
17-Jan-03 375
18-Jan-03 411
19-Jan-03 376
20-Jan-03 435
21-Jan-03 697
22-Jan-03 623
23-Jan-03 657
24-Jan-03 572
25-Jan-03 429
26-Jan-03 401
27-Jan-03 347
28-Jan-03 364
29-Jan-03 358
30-Jan-03 626
31-Jan-03 674
1-Feb-03 756
2-Feb-03 1004
3-Feb-03 588
4-Feb-03 786
5-Feb-03 547
6-Feb-03 454
7-Feb-03 389
8-Feb-03 311
9-Feb-03 418
10-Feb-03 391
11-Feb-03 690
12-Feb-03 670
13-Feb-03 800
14-Feb-03 776
15-Feb-03 846
16-Feb-03 756
17-Feb-03 671
18-Feb-03 555
19-Feb-03 751
20-Feb-03 873
21-Feb-03 715
22-Feb-03 882
23-Feb-03 631
24-Feb-03 479
25-Feb-03 979
26-Feb-03 1050
27-Feb-03 1051
28-Feb-03 959
1-Mar-03 978
2-Mar-03 1160
3-Mar-03 1368
4-Mar-03 1660
5-Mar-03 1675
6-Mar-03 1753
7-Mar-03 1805