This Week's Climate Highlight
Shown below are charts that display the peak stream flow values of selected river sites for the Allegheny, Susquehanna, and Schuylkill Rivers. April, May and June values are shown during years in which seasonal snowfall totals were similar to that of this past winter season. The values in parentheses are the day of the month in which the peak was observed. Also displayed are the average monthly stream flow values that can be compared to the peak values seen during the selected months and years.
Allegheny River, Port Allegheny
| 1978 | 1994 | 1996 | Average Stream Flow Value for Month | ||
| Peak Stream Flow Values | April | 4150 (2) | 4210 (7) | 2110 (14) | 912 |
| (cubic feet per second) | May | 3660 (15) | 1080 (1) | 4100 (12) | 482 |
| June | 393 (9) | 5370 (14) | 468 (19) | 354 |
As evident from the above chart, each peak stream flow value during each month and year were above average, and in some cases, greatly above the average. Generally April and May deviated most from the average, and the Allegheny River in June of 1994 had the greatest deviation from the average June value.
Susquehanna River, Williamsport
|
1971 |
1978 | 1981 | 1982 | 1994 | Average Stream Flow Value for Month | ||
| Peak Stream Flow Values | April | 28800 (14) | 49500 (3) | 48100 (30) | 38900 (2) | 77800 (4) | 18350 |
| (cubic feet per second) | May | 16800 (14) | 70800 (15) | 43500 (1) | 18600 (25) | 17900 (3) | 12230 |
| June | 4700 (16) | 15200 (10) | 22500 (16) | 70500 (6) | 24800 (15) | 7086 |
The Susquehanna River exhibits large values of stream flow rates. Each value is above the average with the exception of June of 1971. It appears from this data that both 1978 and 1994 had stream flow values greatest above average, while the months of 1971 were the least above average.
Schuylkill River, Philadelphia
| 1978 | 1979 | 1994 | 1996 | Average Stream Flow Value for Month | ||
| Peak Stream Flow Values | April | 8330 (1) | 4360 (16) | 14000 (14) | 22800 (2) | 4259 |
| (cubic feet per second) | May | 17400 (15) | 8360 (27) | 5880 (8) | 8610 (12) | 3110 |
| June | 3110 (1) | 5620 (1) | 6170 (7) | 5140 (13) | 2118 |
Once again, we see that during the selected months and their years, all peak stream flow values were above average. Generally, April experienced the values that were most above the average during these years. Of these years, 1996 exhibited the values that were most above the average.
From this data, is it apparent that during a rough winter with above average snowfall, stream flow values are very likely to peak well above average. Therefore, it might be expected that because of this past season's snowfall totals, river levels at these sites as well as others throughout Pennsylvania will likely peak well above average again during the months of April, May and June.