Western Interconnection Frequency Events

Recorded by the PSFM Frequency Monitor — Palo Alto — All times UTC

Showing last 30 days • max 500 events • updated 00:19:09 14-Sep-2026 UTC

09/14/26
Pickup (UTC) Dropout (UTC) Duration Delta (Hz) Slope (Hz/s) Type
00:11:39 00:12:10 31 s +59.934 0.0000 Under 59.940
PU DO 59.976 59.913 00:06:39 00:17:10
00:11:33 00:11:39 6 s +59.937 0.0000 Under 59.940
PU DO 59.976 59.912 00:06:33 00:16:39
00:10:51 00:10:56 5 s +59.938 0.0000 Under 59.940
PU DO 59.976 59.909 00:05:51 00:15:56
00:10:27 00:10:40 13 s +59.935 0.0000 Under 59.940
PU DO 59.976 59.909 00:05:27 00:15:40
00:04:47 00:07:26 159 s +59.928 0.0000 Under 59.940
60.000 PU DO 60.009 59.909 23:59:47 00:12:26
00:04:39 00:04:43 4 s +59.939 0.0000 Under 59.940
60.000 PU DO 60.009 59.909 23:59:39 00:09:43
09/13/26
Pickup (UTC) Dropout (UTC) Duration Delta (Hz) Slope (Hz/s) Type
00:17:41 00:17:49 8 s +59.939 0.0000 Under 59.940
PU DO 59.998 59.912 00:12:41 00:22:49
00:14:30 00:17:30 180 s +59.932 0.0000 Under 59.940
PU DO 59.990 59.912 00:09:30 00:22:30
00:12:26 00:12:51 25 s +59.936 0.0000 Under 59.940
PU DO 59.978 59.912 00:07:26 00:17:51
00:12:15 00:12:22 7 s +59.938 0.0000 Under 59.940
PU DO 59.983 59.912 00:07:15 00:17:22
00:11:15 00:12:02 47 s +59.934 0.0000 Under 59.940
PU DO 59.993 59.912 00:06:15 00:17:02
00:10:48 00:11:04 16 s +59.937 0.0000 Under 59.940
PU DO 59.994 59.912 00:05:48 00:16:04
00:10:34 00:10:46 12 s +59.937 0.0000 Under 59.940
PU DO 59.994 59.912 00:05:34 00:15:46
09/05/26
Pickup (UTC) Dropout (UTC) Duration Delta (Hz) Slope (Hz/s) Type
02:55:23 02:55:27 4 s -0.064 -0.0107 Delta -
60.000 PU DO 60.065 59.916 02:50:23 03:00:27
02:55:21 02:55:28 7 s -0.064 -0.0118 VT ROC
60.000 PU DO 60.065 59.916 02:50:21 03:00:28
09/01/26
Pickup (UTC) Dropout (UTC) Duration Delta (Hz) Slope (Hz/s) Type
17:57:02 17:57:06 4 s -0.066 -0.0107 Delta -
60.000 PU DO 60.052 59.932 17:52:02 18:02:06
17:57:00 17:57:07 7 s -0.066 -0.0128 VT ROC
60.000 PU DO 60.052 59.932 17:52:00 18:02:07
08/27/26
Pickup (UTC) Dropout (UTC) Duration Delta (Hz) Slope (Hz/s) Type
22:55:35 22:55:41 6 s +0.073 0.0107 Delta +
60.000 PU DO 60.072 59.941 22:50:35 23:00:41
22:55:32 22:55:41 9 s +0.072 0.0110 VT ROC
60.000 PU DO 60.072 59.941 22:50:32 23:00:41
20:25:24 20:25:34 10 s +59.935 0.0000 Under 59.940
60.000 PU DO 60.029 59.911 20:20:24 20:30:34
06:55:40 06:55:58 18 s +59.934 0.0000 Under 59.940
60.000 PU DO 60.039 59.912 06:50:40 07:00:58
06:24:11 06:24:15 4 s -0.066 -0.0103 Delta -
60.000 PU DO 60.054 59.926 06:19:11 06:29:15
06:24:08 06:24:16 8 s -0.065 -0.0115 VT ROC
60.000 PU DO 60.054 59.926 06:19:08 06:29:16
02:55:33 02:55:38 5 s -0.070 -0.0115 Delta -
60.000 PU DO 60.055 59.923 02:50:33 03:00:38
02:55:31 02:55:38 7 s -0.069 -0.0129 VT ROC
60.000 PU DO 60.055 59.923 02:50:31 03:00:38
08/25/26
Pickup (UTC) Dropout (UTC) Duration Delta (Hz) Slope (Hz/s) Type
02:55:36 02:55:39 3 s -0.063 -0.0091 Delta -
60.000 PU DO 60.048 59.924 02:50:36 03:00:39
02:55:34 02:55:41 7 s -0.062 -0.0100 VT ROC
60.000 PU DO 60.048 59.924 02:50:34 03:00:41