NWS Jackson, MS Recreational Forecast for the Ross Barnett Reservoir

Recreational Forecast for the Lakes and Reservoirs

The National Weather Service in Jackson now issues a Recreational Forecast for the lakes and reservoirs in our area of responsibility.

The forecast may be accessed at this link:

http://forecast.weather.gov/product.php?site=JAN&product=REC&issuedby=JAN

Product Description

The Recreational Forecast will include an indication of expected winds, waves, and weather. The wave forecast will depend on the direction and speed of the winds and will be represented by a degree of chop or roughness. Based on the wind direction, a portion of the Reservoir will be indicated that should experience the highest waves. See the charts below for more specific information.

Wave Descriptions

The following chart will be used to assign a wave category.

Wind Speed (mph)	Wave Category
7-12	light chop
13-17	moderate chop
18-22	choppy
23-27	rough
28-32	very rough
> 32	extremely rough

The following wind direction scheme will be used to determine wave wording. The wave category in these statements will be based on the wind speed as shown in the previous table.

Wind Direction	REC Wave Wording
000° - 045°	Lake waters [wave category]...choppiest lower reservoir...especially near the Spillway.
045° - 060°	Lake waters [wave category]...choppiest western waters...especially near the Spillway.
060° - 135°	Lake waters [wave category]...choppiest western waters.
135° - 225°	Lake waters [wave category]...choppiest upper reservoir.
225° - 270°	Lake waters [wave category]...choppiest eastern waters.
270° - 315°	Lake waters [wave category]...choppiest eastern waters…especially near the Causeway.
315° - 360°	Lake waters [wave category]...choppiest lower reservoir.

The maps below provide a graphical explanation as to why a particular wind direction will result in choppier waves in a particular section of the reservoir. The arrows represent the wind direction. You can click on any of the maps for a higher-resolution version.

These two examples will cause waves to be highest on the east side of the reservoir.

This example will cause waves to be highest on the lower reservoir.

This example will cause waves to be highest near the Spillway.

These examples will cause waves to be highest on the west side of the reservoir.

This example will cause waves to be highest on the upper reservoir.

Headlines

When needed, a headline will be included in the Recreational forecast. Below are the criteria for headlines that will be used in the REC product.

Lake Wind Advisory - sustained winds greater than 20 mph with gusts to 30 mph
Wind Advisory - sustained winds 25 to 30 mph with gusts above 40 mph
High Wind Warning - sustained winds 40 mph with gusts to near 60 mph
Tropical Storm Warning - sustained winds of at least 39 mph when associated with a tropical system
Hurricane Warning - sustained winds of at least 74 mph when associated with a tropical system
Dense Fog Advisory - visibility less than ¼ mile
Wind Chill Advisory - wind chill less than 0°F

Note: Winter Storm headlines will supersede the issuance of wind headlines.

National Weather Service Weather Forecast Office