Expected

* WHAT...Heat index values up to 109 expected. * WHERE...Portions of central, east central, northern, northwest, southeast, southern, southwest, and western Oklahoma and northern Texas. * WHEN...From 11 AM this morning to 9 PM CDT this evening. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.

* WHAT...Heat index values 105 TO 109. * WHERE...Portions of south central and southwest Arkansas, north central and northwest Louisiana, southeast Oklahoma, and east and northeast Texas. * WHEN...Until 8 PM CDT this evening. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Take extra precautions when outside. Wear lightweight and loose

* WHAT...High risk of rip currents expected. * WHERE...Erie, Lorain, Cuyahoga, Lake and Ashtabula Lakeshore Counties. * WHEN...From 8 AM EDT this morning through late Wednesday night. * IMPACTS...Wind and wave action will cause currents on the lakeshore. Swimmers should not enter the water. Currents can carry swimmers away from shore through a sand bar and along structures extending out into the lake. Remain out of the water to avoid hazardous swimming conditions.

* WHAT...High risk of rip currents expected. * WHERE...Northern Erie County. * WHEN...From 2 PM EDT this afternoon through Wednesday afternoon. * IMPACTS...Wind and wave action will cause currents on the lakeshore. Swimmers should not enter the water. Currents can carry swimmers away from shore through a sand bar and along structures extending out into the lake. Remain out of the water to avoid hazardous swimming conditions.

* WHAT...Long-period southerly swell will bring an increased risk of sneaker waves and strong rip currents. Breaking waves will reach up to 10 feet along some south and southwest facing beaches and break points. * WHERE...Pacific Coast beaches. * WHEN...Through Saturday afternoon. * IMPACTS...Dangerous conditions are forecast along the shoreline. Hazards include sneaker waves, strong rip currents, and large breaking waves. Stay off of jetties, piers, rocks, and other waterside

* WHAT...Visibility one quarter mile or less in dense fog. * WHERE...In Minnesota, Kittson County. In North Dakota, Benson, Cavalier, Eddy, Nelson, Pembina, Ramsey, Towner, Western Walsh, and Griggs Counties. * WHEN...Until 10 AM CDT Thursday. * IMPACTS...Low visibility could make driving conditions hazardous. If driving, slow down, use your headlights, and leave plenty of distance ahead of you.

* WHAT...Dense fog will reduce visibility to less than one nautical mile. * WHERE...Portions of Central and Eastern Lake Superior. * WHEN...Until 8 AM EDT this morning. * IMPACTS...Low visibility will make navigation difficult. If you must navigate, proceed with caution. Use proper fog signals. Make sure all running lights are on. Remember to use your radar and compass.

* WHAT...Dense fog will reduce visibility to less than one nautical mile. * WHERE...Portions of Western Lake Superior. * WHEN...Until noon EDT /11 AM CDT/ today. * IMPACTS...Low visibility will make navigation difficult. If you must navigate, proceed with caution. Use proper fog signals. Make sure all running lights are on. Remember to use your radar and compass.

* WHAT...High wave action, strong currents, and dangerous swimming conditions expected. Piers may be heavily swamped by waves. * WHERE...Mason, Oceana, Muskegon, Ottawa, Allegan and Van Buren counties. * WHEN...Through late Tuesday night. * IMPACTS...Strong currents can pull swimmers into deeper water and high waves can sweep people off piers. * ADDITIONAL DETAILS...Beaches on the north side of north facing piers will be most dangerous. Remain out of the water to avoid hazardous swimming conditions

* WHAT...Visibility one quarter mile or less in dense fog. * WHERE...Portions of northwest and north central North Dakota, including the northern James River Valley. * WHEN...Until 10 AM CDT this morning. * IMPACTS...Low visibility could make driving conditions hazardous. If driving, slow down, use your headlights, and leave plenty of distance ahead of you.