Station 46027 (LLNR 562) - ST GEORGES - 8 NM NW of Crescent City, CA Image indicating link to RSS feed of recent meteorological observations for station 46027


Conditions at 46027 as of
(3:50 pm PDT)
2250 GMT on 07/20/2026:
     

Click on the graph icon in the table below to see a time series plot of the last five days of that observation.

5-day plot - Wind Direction Wind Direction (WDIR): SE ( 130 deg true )
5-day plot - Wind Speed Wind Speed (WSPD): 0.0 kts
5-day plot - Wind Gust Wind Gust (GST): 1.9 kts
5-day plot - Wave Height Wave Height (WVHT): 6.2 ft
5-day plot - Dominant Wave Period Dominant Wave Period (DPD): 8 sec
5-day plot - Average Wave Period Average Period (APD): 6.2 sec
5-day plot - Mean Wave Direction Mean Wave Direction (MWD):NNW ( 331 deg true )
5-day plot - Atmospheric Pressure Atmospheric Pressure (PRES):29.95 in
5-day plot - Air Temperature Air Temperature (ATMP): 57.9 °F
5-day plot - Dew Point Dew Point (DEWP): 54.7 °F
5-day plot - Wind Speed at 10 Meters Wind Speed at 10 meters (WSPD10M): 0.0 kts
5-day plot - Wind Speed at 20 Meters Wind Speed at 20 meters (WSPD20M): 0.0 kts
5-day plot -  Wind Speed, Wind Gust and Atmospheric Pressure Combined plot of Wind Speed, Gust, and Air Pressure
Supplemental Measurements
Lowest 1-minute Pressure
Time (PDT)Pressure
3:49 pm29.95 in
Highest 1-minute Wind Speed
Time (PDT)5-day plot - 1-Minute Wind Speed WSPD 5-day plot - 1-Minute Wind Direction WDIR
3:47 pm 0.0 ktsNNE ( 12 deg true )
Previous observations
TIME
(PDT)
5-day plot - Wind Direction
WDIR
 
5-day plot - Wind Speed
WSPD
kts
5-day plot - Wind Gust
GST
kts
5-day plot - Wave Height
WVHT
ft
5-day plot - Dominant Wave Period
DPD
sec
5-day plot - Average Wave Period
APD
sec
5-day plot - Mean Wave Direction
MWD
 
5-day plot - Atmospheric Pressure
PRES
in
5-day plot - Pressure Tendency
PTDY
in
5-day plot - Air Temperature
ATMP
°F
5-day plot - Water Temperature
WTMP
°F
5-day plot - Dew Point
DEWP
°F
5-day plot - Salinity
SAL
psu
5-day plot - Visibility
VIS
nmi
5-day plot - Tide (above MLLW)
TIDE
ft
2026-07-20 03:40 pm SW 0.0 1.9----29.96- 57.7- 54.5---
2026-07-20 03:30 pm W 0.0 1.9----29.95- 57.6- 54.5---
2026-07-20 03:20 pmSSW 0.0 1.9 6.2 96.2 NW29.96- 57.6- 54.5---
2026-07-20 03:10 pm SW 1.9 1.9----29.95- 57.2- 54.5---
2026-07-20 03:00 pmSSW 1.9 3.9----29.95+0.00 57.2- 54.5---
2026-07-20 02:50 pm S 1.9 3.9 6.2 86.2NNW29.95- 57.0- 54.7---
2026-07-20 02:40 pmSSW 1.9 3.9----29.95- 57.0- 54.7---
2026-07-20 02:30 pmSSW 1.9 3.9----29.95- 56.7- 54.5---
2026-07-20 02:20 pmSSW 3.9 5.8 6.9 86.4NNW29.95- 56.7- 54.5---
2026-07-20 02:10 pm S 3.9 5.8 6.9-6.4NNW29.95- 56.5- 54.3---
2026-07-20 02:00 pm S 5.8 7.8----29.95+0.00 56.3- 54.1---
2026-07-20 01:50 pm S 7.8 9.7 5.9 86.2 NW29.95- 56.3- 54.1---
2026-07-20 01:40 pm S 7.8 9.7----29.96- 56.3- 54.3---
2026-07-20 01:30 pm S 7.8 9.7----29.96- 56.3- 54.0---
2026-07-20 01:20 pm S 9.7 11.7 6.6 86.4 NW29.95- 56.3- 54.1---
2026-07-20 01:10 pm S 7.8 9.7 6.6-6.4 NW29.96- 56.5- 54.3---
2026-07-20 01:00 pm S 7.8 9.7----29.96+0.01 56.3- 54.1---
2026-07-20 12:50 pm S 7.8 7.8 6.9 86.6 NW29.96- 56.3- 54.3---
2026-07-20 12:40 pm S 5.8 7.8----29.95- 56.1- 54.3---
2026-07-20 12:30 pmSSW 5.8 7.8----29.96- 56.1- 54.7---
2026-07-20 12:20 pmSSW 3.9 5.8 6.6 96.5 NW29.95- 56.1- 54.9---
2026-07-20 12:10 pm S 5.8 7.8----29.96- 55.9- 54.7---
2026-07-20 12:00 pm S 3.9 7.8----29.96+0.04 55.8- 54.7---
2026-07-20 11:50 am S 3.9 5.8 6.2 86.3 NW29.95- 55.6- 54.5---
2026-07-20 11:40 am S 3.9 5.8----29.95- 55.4- 54.5---
2026-07-20 11:30 amSSW 3.9 7.8----29.95- 55.4- 54.7---
2026-07-20 11:20 am S 3.9 5.8 6.9 86.5 NW29.95- 55.4- 54.7---
2026-07-20 11:10 amSSE 5.8 7.8----29.95- 55.2- 54.5---
2026-07-20 11:00 amESE 5.8 9.7----29.94+0.03 55.0- 54.3---
2026-07-20 10:50 amESE 5.8 7.8 6.9 86.5 NW29.94- 55.2- 54.5---
2026-07-20 10:40 amESE 7.8 13.6----29.94- 54.9- 54.1---
2026-07-20 10:30 amESE 11.7 15.5----29.93- 54.7- 54.0---
2026-07-20 10:20 am SE 11.7 15.5 6.9 86.3 NW29.93- 54.5- 53.8---
2026-07-20 10:10 am SE 7.8 11.7----29.94- 54.5- 53.8---
2026-07-20 10:00 am SE 3.9 7.8----29.94+0.04 54.5- 53.8---
2026-07-20 09:50 amSSE 1.9 3.9 6.6 86.2 NW29.94- 54.3- 53.6---
2026-07-20 09:40 am W 0.0 1.9----29.93- 54.1- 53.4---
2026-07-20 09:30 am NW 3.9 5.8----29.93- 54.1- 53.4---
2026-07-20 09:20 am NW 3.9 5.8 6.9 86.4 NW29.93- 54.1- 53.4---
2026-07-20 09:10 am N 3.9 5.8 6.9-6.4 NW29.92- 54.1- 53.4---
2026-07-20 09:00 am N 3.9 5.8----29.92+0.01 54.3- 53.6---
2026-07-20 08:50 am NE 3.9 5.8 6.9 86.3 NW29.91- 54.3- 53.6---
2026-07-20 08:40 amENE 1.9 5.8 6.9-6.3 NW29.91- 54.1- 53.4---
2026-07-20 08:30 am N 0.0 1.9----29.91- 54.1- 53.4---
2026-07-20 08:20 am SE 0.0 1.9 6.6 86.4 NW29.91- 54.1- 53.4---
2026-07-20 08:10 amSSE 3.9 5.8 6.6-6.4 NW29.91- 54.1- 53.4---
2026-07-20 08:00 am S 5.8 7.8----29.92+0.03 54.3- 53.6---
2026-07-20 07:50 am S 5.8 7.8 6.6 86.4 NW29.93- 54.3- 53.6---
2026-07-20 07:40 amSSE 5.8 7.8----29.93- 54.3- 53.6---
2026-07-20 07:30 amSSE 5.8 7.8----29.92- 54.5- 53.8---
2026-07-20 07:20 am SE 5.8 7.8 7.2 86.5 NW29.91- 54.3- 53.6---
2026-07-20 07:10 am SE 3.9 5.8----29.91- 54.1- 53.4---
2026-07-20 07:00 am SE 3.9 7.8----29.91+0.01 54.1- 53.4---
2026-07-20 06:50 am SE 5.8 7.8 6.9 86.3 NW29.91- 54.1- 53.4---
2026-07-20 06:40 amSSE 5.8 7.8----29.90- 54.1- 53.4---
2026-07-20 06:30 am SE 5.8 7.8----29.90- 54.1- 53.4---
2026-07-20 06:20 am SE 3.9 7.8 6.9 86.4 NW29.89- 54.1- 53.4---
2026-07-20 06:10 am SE 3.9 5.8 6.9-6.4 NW29.90- 54.0- 53.2---
2026-07-20 06:00 amSSE 5.8 7.8----29.90+0.00 54.0- 53.2---
2026-07-20 05:50 am SE 5.8 9.7 6.6 86.4 NW29.90- 54.0- 53.2---
2026-07-20 05:40 amSSE 5.8 7.8----29.89- 54.0- 53.2---
2026-07-20 05:30 amSSE 3.9 5.8----29.90- 53.8- 53.1---
2026-07-20 05:20 am SE 1.9 3.9 6.2 86.2 NW29.89- 53.8- 53.1---
2026-07-20 05:10 am SE 1.9 3.9----29.89- 53.6- 52.9---
2026-07-20 05:00 am SE 1.9 1.9----29.89+0.00 53.6- 52.9---
2026-07-20 04:50 am S 1.9 3.9 6.6 86.2 NW29.89- 53.6- 52.9---
2026-07-20 04:40 amESE 1.9 3.9----29.89- 53.6- 52.9---
2026-07-20 04:30 amWSW 1.9 3.9----29.88- 53.4- 52.7---
2026-07-20 04:20 amWSW 3.9 3.9 6.2 86.1 NW29.88- 53.6- 52.9---
2026-07-20 04:10 am SW 3.9 3.9 6.2-6.1 NW29.89- 53.6- 52.9---
2026-07-20 04:00 am S 3.9 5.8----29.90+0.00 53.6- 52.9---
2026-07-20 03:50 am SE 3.9 5.8 6.9 86.4 NW29.89- 53.4- 52.7---
2026-07-20 03:40 amSSE 3.9 5.8----29.89- 53.4- 52.7---
2026-07-20 03:30 amSSE 3.9 5.8----29.89- 53.2- 52.5---
2026-07-20 03:20 amSSE 3.9 5.8 6.6 86.4 NW29.89- 53.2- 52.5---
2026-07-20 03:10 amSSE 3.9 7.8 6.6-6.4 NW29.89- 53.1- 52.3---
2026-07-20 03:00 am S 3.9 7.8----29.90-0.01 53.2- 52.5---
2026-07-20 02:50 am S 5.8 7.8 7.2 86.5 NW29.90- 53.2- 52.5---
2026-07-20 02:40 am S 3.9 5.8----29.90- 53.2- 52.5---
2026-07-20 02:30 amSSW 3.9 5.8----29.89- 53.4- 52.7---
2026-07-20 02:20 am SW 3.9 3.9 6.9 86.5 NW29.90- 53.2- 52.5---
2026-07-20 02:10 amWSW 3.9 5.8 6.9-6.5 NW29.89- 53.2- 52.5---
2026-07-20 02:00 amSSW 1.9 3.9----29.89-0.01 53.6- 52.9---
2026-07-20 01:50 am SE 1.9 3.9 7.5 86.5 NW29.89- 53.4- 52.7---
2026-07-20 01:40 am S 1.9 3.9 7.5-6.5 NW29.89- 53.2- 52.5---
2026-07-20 01:30 amSSE 1.9 3.9----29.89- 53.2- 52.5---
2026-07-20 01:20 am SE 3.9 5.8 7.5 86.5NNW29.90- 53.1- 52.3---
2026-07-20 01:10 am SE 1.9 5.8 7.5-6.5NNW29.90- 53.2- 52.5---
2026-07-20 01:00 am S 0.0 1.9----29.90-0.01 53.2- 52.5---
2026-07-20 12:50 amSSE 0.0 1.9 7.2 86.3 NW29.90- 53.2- 52.5---
2026-07-20 12:40 amESE 0.0 1.9----29.90- 53.1- 52.3---
2026-07-20 12:30 am E 0.0 3.9----29.90- 53.1- 52.3---
2026-07-20 12:20 amESE 1.9 3.9 8.2-6.8 NW29.91- 52.9- 52.2---
2026-07-20 12:10 am--- 8.2 86.8 NW--------
2026-07-20 12:00 amESE 1.9 3.9----29.90+0.00 52.7- 52.0---
2026-07-19 11:50 pm E 1.9 5.8 8.2 86.6 NW29.90- 52.7- 52.0---
2026-07-19 11:40 pmNNE 0.0 1.9----29.90- 52.5- 51.8---
2026-07-19 11:30 pmENE 0.0 1.9----29.91- 52.5- 51.8---
2026-07-19 11:20 pmESE 1.9 3.9 7.9 86.5 NW29.91- 52.3- 51.6---
2026-07-19 11:10 pmESE 1.9 3.9 7.9-6.5 NW29.91- 52.3- 51.6---
2026-07-19 11:00 pmESE 1.9 5.8----29.91+0.01 52.2- 51.4---
2026-07-19 10:50 pm SE 3.9 5.8 8.2 86.5 NW29.91- 52.0- 51.3---
2026-07-19 10:40 pm SE 1.9 5.8----29.91- 52.0- 51.3---
2026-07-19 10:30 pm SE 1.9 3.9----29.91- 51.8- 51.1---
2026-07-19 10:20 pmSSE 1.9 5.8 7.9 86.5 NW29.90- 51.6- 50.9---
2026-07-19 10:10 pm S 1.9 3.9----29.91- 51.3- 50.5---
2026-07-19 10:00 pm S 3.9 5.8----29.91+0.02 51.1- 50.4---
2026-07-19 09:50 pm SE 3.9 7.8 8.2 86.5 NW29.91- 50.9- 50.2---
2026-07-19 09:40 pm SE 3.9 5.8----29.91- 50.7- 50.0---
2026-07-19 09:30 pm E 1.9 3.9----29.91- 50.7- 50.0---
2026-07-19 09:20 pm NE 1.9 3.9 8.9 86.7 NW29.91- 50.5- 49.8---
2026-07-19 09:10 pm NE 0.0 3.9 8.9-6.7 NW29.90- 50.4- 49.6---
2026-07-19 09:00 pm E 1.9 3.9----29.90+0.00 50.4- 49.6---
2026-07-19 08:50 pm E 1.9 3.9 8.9 86.8 NW29.90- 50.5- 49.8---
2026-07-19 08:40 pmENE 1.9 5.8----29.90- 50.4- 49.6---
2026-07-19 08:30 pm NE 1.9 3.9----29.90- 50.5- 49.8---
2026-07-19 08:20 pm NE 1.9 3.9 7.9 86.5 NW29.90- 50.5- 49.8---
2026-07-19 08:10 pm N 1.9 3.9 7.9-6.5 NW29.90- 50.5- 49.8---
2026-07-19 08:00 pm N 3.9 3.9----29.90-0.03 50.7- 50.0---
2026-07-19 07:50 pm N 3.9 5.8 7.9 86.4 NW29.89- 50.7- 50.0---
2026-07-19 07:40 pmNNW 3.9 5.8----29.89- 50.7- 50.0---
2026-07-19 07:30 pm N 3.9 5.8----29.89- 50.7- 50.0---
2026-07-19 07:20 pm N 3.9 5.8 8.2 86.7 NW29.89- 50.9- 50.2---
2026-07-19 07:10 pm N 5.8 7.8 8.2-6.7 NW29.89- 51.3- 50.5---
2026-07-19 07:00 pm N 5.8 7.8----29.89-0.05 51.3- 50.5---
2026-07-19 06:50 pm N 5.8 7.8 8.2 86.6NNW29.89- 51.3- 50.5---
2026-07-19 06:40 pm N 7.8 9.7----29.89- 51.3- 50.5---
2026-07-19 06:30 pm N 7.8 7.8----29.89- 51.4- 50.7---
2026-07-19 06:20 pm N 7.8 9.7 6.9 86.3 NW29.90- 51.4- 50.7---
2026-07-19 06:10 pm N 7.8 9.7 6.9-6.3 NW29.90- 51.8- 51.1---
2026-07-19 06:00 pmNNW 7.8 11.7----29.90-0.05 51.8- 51.1---
2026-07-19 05:50 pmNNW 7.8 11.7 7.9 86.6NNW29.91- 51.8- 51.1---
2026-07-19 05:40 pmNNW 7.8 11.7 7.9-6.6NNW29.90- 51.8- 51.1---
2026-07-19 05:30 pmNNW 7.8 9.7----29.91- 51.8- 51.1---
2026-07-19 05:20 pmNNW 5.8 9.7 6.9 86.4 NW29.91- 51.6- 50.9---
2026-07-19 05:10 pmNNW 3.9 7.8 6.9-6.4 NW29.92- 51.6- 50.9---
2026-07-19 05:00 pmNNW 5.8 7.8----29.93-0.04 52.0- 51.3---
2026-07-19 04:50 pmNNW 5.8 9.7 6.6 96.3 NW29.92- 52.2- 51.4---
2026-07-19 04:40 pmNNW 5.8 7.8----29.93- 52.0- 51.3---
2026-07-19 04:30 pm N 3.9 7.8----29.93- 52.2- 51.4---
2026-07-19 04:20 pmNNW 3.9 5.8 6.6 86.3 NW29.93- 52.2- 51.4---
2026-07-19 04:10 pmNNW 1.9 3.9 6.6-6.3 NW29.93- 52.3- 51.6---
2026-07-19 04:00 pm NW 1.9 3.9----29.93-0.04 52.5- 51.8---
2026-07-19 03:50 pmWNW 1.9 3.9 6.6 86.4 NW29.94- 52.5- 51.8---

Wave Summary
for 46027 as of (3:40 pm PDT)
2240 GMT on 07/20/2026:

These wave data are displayed in rounded times.

     

Click on the graph icon in the table below to see a time series plot of the last five days of that observation.

5-day plot - Significant Wave Height Significant Wave Height (WVHT): 6.2 ft
5-day plot - Swell Height Swell Height (SwH): 5.9 ft
5-day plot - Swell Period Swell Period (SwP): 8.3 sec
5-day plot - Swell Direction Swell Direction (SwD):NNW
5-day plot - Wind Wave Height Wind Wave Height (WWH): 2.0 ft
5-day plot - Wind Wave Period Wind Wave Period (WWP): 3.6 sec
5-day plot - Wind Wave Direction Wind Wave Direction (WWD):WNW
5-day plot - Wave Steepness Wave Steepness (STEEPNESS): AVERAGE
5-day plot - Average Wave Period Average Wave Period (APD): 6.2 sec
Previous observations
TIME
(PDT)
5-day plot - Wave Height
WVHT
ft
5-day plot - Swell Height
SwH
ft
5-day plot - Swell Period
SwP
sec
5-day plot - Swell Direction
SwD
 
5-day plot - Wind Wave Height
WWH
ft
5-day plot - Wind Wave Period
WWP
sec
5-day plot - Wind Wave Direction
WWD
 
5-day plot - Wave Steepness
STEEPNESS
 
5-day plot - Average Wave Period
APD
sec
2026-07-20 03:10 pm 6.2 5.9 9.1 NW 2.0 4.0 NW AVERAGE 6.2
2026-07-20 02:40 pm 6.2 5.9 8.3NNW 2.0 2.9 S AVERAGE 6.2
2026-07-20 02:10 pm 6.9 6.6 8.3NNW 1.6 3.7 W AVERAGE 6.4
2026-07-20 01:40 pm 5.9 5.9 7.7 NW 1.6 3.4 WNW STEEP 6.2
2026-07-20 01:10 pm 6.6 6.6 8.3 NW 1.6 3.7 NW AVERAGE 6.4
2026-07-20 12:40 pm 6.9 6.6 8.3 NW 1.6 3.0 WSW AVERAGE 6.6
2026-07-20 12:10 pm 6.6 6.2 9.1 NW 1.6 3.4 NW AVERAGE 6.5
2026-07-20 11:40 am 6.2 5.9 8.3 NW 1.6 4.0 NW AVERAGE 6.3
2026-07-20 11:10 am 6.9 6.6 7.7 NW 1.6 4.0 NW STEEP 6.5
2026-07-20 10:40 am 6.9 6.9 8.3 NW 2.0 3.7 NW AVERAGE 6.5
2026-07-20 10:10 am 6.9 6.9 8.3 NW 2.0 3.6 NW AVERAGE 6.3
2026-07-20 09:40 am 6.6 6.2 8.3 NW 1.6 4.0 WNW AVERAGE 6.2
2026-07-20 09:10 am 6.9 6.9 7.7 NW 2.0 3.7 NW STEEP 6.4
2026-07-20 08:40 am 6.9 6.6 8.3 NW 2.0 3.7 NW AVERAGE 6.3
2026-07-20 08:10 am 6.6 6.6 8.3 NW 1.6 4.0 NW AVERAGE 6.4
2026-07-20 07:40 am 6.6 6.2 8.3 NW 1.6 3.4 NW AVERAGE 6.4
2026-07-20 07:10 am 7.2 6.9 8.3 NW 1.6 3.8 NW STEEP 6.5
2026-07-20 06:40 am 6.9 6.6 8.3 NW 2.0 3.3 NW AVERAGE 6.3
2026-07-20 06:10 am 6.9 6.9 8.3 NW 1.6 4.0 NW AVERAGE 6.4
2026-07-20 05:40 am 6.6 6.2 7.7 NW 1.6 3.8 NW STEEP 6.4
2026-07-20 05:10 am 6.2 5.9 7.7 NW 1.6 4.0 NW STEEP 6.2
2026-07-20 04:40 am 6.6 6.2 8.3 NW 1.6 3.8 NW AVERAGE 6.2
2026-07-20 04:10 am 6.2 5.9 8.3 NW 1.6 4.0 NW AVERAGE 6.1
2026-07-20 03:40 am 6.9 6.6 8.3 NW 1.6 3.7 NW AVERAGE 6.4
2026-07-20 03:10 am 6.6 6.6 7.7 NW 1.6 3.7 NW STEEP 6.4
2026-07-20 02:40 am 7.2 7.2 8.3 NW 1.6 3.8 NNW STEEP 6.5
2026-07-20 02:10 am 6.9 6.6 8.3 NW 1.6 3.6 NW AVERAGE 6.5
2026-07-20 01:40 am 7.5 7.2 8.3 NW 2.0 4.0 NNW STEEP 6.5
2026-07-20 01:10 am 7.5 7.2 7.7NNW 1.6 3.7 NW STEEP 6.5
2026-07-20 12:40 am 7.2 6.9 8.3 NW 2.0 4.0 NW STEEP 6.3
2026-07-20 12:10 am 8.2 7.9 8.3 NW 1.6 3.7 NNW STEEP 6.8
2026-07-19 11:40 pm 8.2 8.2 8.3 NW 2.0 3.6 WNW STEEP 6.6
2026-07-19 11:10 pm 7.9 7.5 8.3 NW 2.0 4.0 NW STEEP 6.5
2026-07-19 10:40 pm 8.2 8.2 8.3 NW 2.0 3.2 NW STEEP 6.5
2026-07-19 10:10 pm 7.9 7.5 8.3 NW 2.0 4.0 NW STEEP 6.5
2026-07-19 09:40 pm 8.2 7.9 7.7 NW 2.0 3.1 NW STEEP 6.5
2026-07-19 09:10 pm 8.9 8.9 8.3 NW 2.0 3.8 NW STEEP 6.7
2026-07-19 08:40 pm 8.9 8.5 8.3 NW 1.6 3.7 NW STEEP 6.8
2026-07-19 08:10 pm 7.9 7.9 8.3 NW 2.0 3.8 NNW STEEP 6.5
2026-07-19 07:40 pm 7.9 7.5 8.3 NW 2.0 3.8 NW STEEP 6.4
2026-07-19 07:10 pm 8.2 8.2 8.3 NW 1.6 3.3 NW STEEP 6.7
2026-07-19 06:40 pm 8.2 7.9 7.7NNW 1.6 3.4 NW STEEP 6.6
2026-07-19 06:10 pm 6.9 6.6 8.3 NW 1.6 3.8 NW AVERAGE 6.3
2026-07-19 05:40 pm 7.9 7.5 7.7NNW 2.0 4.2 NW STEEP 6.6
2026-07-19 05:10 pm 6.9 6.6 8.3 NW 1.6 3.8 NW AVERAGE 6.4
2026-07-19 04:40 pm 6.6 6.2 9.1 NW 1.6 3.8 NW AVERAGE 6.3
2026-07-19 04:10 pm 6.6 6.2 7.7 NW 1.6 3.8 NW STEEP 6.3

Plot icon Plot of wave energy versus frequency (and period)