Tropical Weather Discussion...UPDATED NWS National Hurricane Center Miami FL 810 AM EDT Sun Aug 20 2017 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. ...UPDATED TO PLACE TROPICAL WAVE IN SPECIAL FEATURES SECTION... Based on 0600 UTC surface analysis and satellite imagery through 1030 UTC. ...SPECIAL FEATURES... A tropical wave extends across the central Caribbean with axis extending from 19N72W to a 1008 mb surface low near 14N72W to 11N73W. This system was previously T.S Harvey. Scattered moderate convection has developed during the past few hours near the low center mainly from 12N-17N between 73W-77W. A fast westward motion is expected to continue with this system for the next couple of days as the wave moves along the southern periphery of the subtropical ridge. ...TROPICAL WAVES... A tropical wave extends its axis from 20N45W to 10N46W, moving west at 15-20 kt. Satellite imagery indicates a large area of cloudiness but convection is limited in association with this wave due to Saharan dust intrusion. This system coincides with a well defined 700 mb trough, and a high amplitude northward bulge of moisture is noted on the TPW product. A tropical wave was introduced to this map over the eastern Caribbean, after analyzing upper-air soundings across the islands and model guidance. The wave's axis extends from 19N65W to 10N64W, moving west at 10-15 kt. Scattered showers are noted over the northern portion of the wave mainly north of 16N between 62W-66W affecting the Leeward Islands, the U.S. Virgin Islands, and Puerto Rico. A tropical wave is over the western Caribbean with axis extending from western Cuba along 84W to near 10N84W, moving west at 10-15 kt. The wave shows up very well on the TPW animation and 700 mb streamline analysis. Energy from the wave has fractured to the northeast and is analyzed as a surface trough currently located over the Florida Peninsula. The wave is enhancing showers near Honduras, Belize and adjacent waters. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 15N17W to a 1008 mb low near 13N20W to 11N41W. The Intertropical Convergence Zone extends from 11N51W to 09N61W. Scattered moderate convection is observed within 100 nm on either side of the monsoon trough. ...DISCUSSION... GULF OF MEXICO... A large and well defined upper-level low centered over the southeast Gulf near 25N85W continues to generate scattered showers over the Florida Straits. The western half of the Gulf is under the influence of a surface ridge, anchored by a 1016 mb high pressure centered near 29N90W. Isolated showers and light to gentle anticyclonic winds prevail west of 90W. The upper-low will drift westward reaching the central Gulf by Monday. This system will continue to enhance showers and thunderstorms across the Gulf waters today. CARIBBEAN SEA... Three tropical waves are moving across the basin. Refer to the section above for details. Moisture associated with these tropical waves will continue to affect the area increasing the likelihood of showers and thunderstorms today. Scatterometer data depicts moderate trades across the basin, with the strongest winds remaining east of 70W. ...HISPANIOLA... Daytime heating, local sea breezes, and mountain upslope lifting will combine with available moisture to produce scattered showers and thunderstorms across the island mainly during the afternoon and evening hours through the weekend. ATLANTIC OCEAN... As previously mentioned, the northern part of the tropical wave currently moving across the western Caribbean is analyzed as a trough currently extending across southeast Florida. This trough is generating scattered showers and thunderstorms west of 76W, and will continue to move westward through the day. Another surface trough is analyzed northeast of the Leeward Islands extending from 25N65W to 20N65W. This trough continues to produce disorganized showers and thunderstorms from 19N-25N between 61W-66W. Environmental conditions are not expected to be conducive for development of this system during the next couple of days while it moves west- northwestward at 15 to 20 kt. An area of fresh to strong winds is noted per scatterometer data on the northern side of this trough. The remainder of the Atlantic is under the influence of a surface ridge, anchored by a 1023 mb high centered near 32N39W. Fresh to strong northerly winds are also noted between the coast of Africa and the Madeira/Canary Islands. These winds are the result of the pressure gradient between the Atlantic ridge and lower pressures over west Africa. The Central Pressure
Hazardous Weather Outlook
Hazardous Weather Outlook National Weather Service Jackson MS 403 AM CDT Sun Aug 20 2017 ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074- 210915- Ashley-Chicot-Morehouse-West Carroll-East Carroll-Richland- Madison LA-Franklin LA-Catahoula-Tensas-Concordia-Bolivar- Sunflower-Leflore-Grenada-Carroll-Montgomery-Webster-Clay-Lowndes- Choctaw-Oktibbeha-Washington-Humphreys-Holmes-Attala-Winston- Noxubee-Issaquena-Sharkey-Yazoo-Madison MS-Leake-Neshoba-Kemper- Warren-Hinds-Rankin-Scott-Newton-Lauderdale-Claiborne-Copiah- Simpson-Smith-Jasper-Clarke-Jefferson-Adams-Franklin MS-Lincoln- Lawrence-Jefferson Davis-Covington-Jones-Marion-Lamar-Forrest- 403 AM CDT Sun Aug 20 2017 This hazardous weather outlook is for portions of southeast Arkansas, northeast Louisiana, central Mississippi, north central Mississippi, and south central Mississippi. .DAY ONE...Today and Tonight EXCESSIVE HEAT THREAT...Elevated TIMING...Today Temperatures in the mid to upper 90s are expected to combine with dewpoints in the mid to upper 70s on Sunday. This will result in heat index values ranging from 105-110 degrees from 11AM til 7PM. Exposure to these conditions will raise the likelihood of heat related illnesses. (www.weather.gov/images/jan/graphicast/image1.png) .DAYS TWO THROUGH SEVEN...Monday through Saturday Maximum heat index values near 105 degrees are possible in the Delta region on Monday. Prolonged exposure to these temperatures or strenuous outdoor activities could be dangerous. (www.weather.gov/images/jan/graphicast/image2.png) .SPOTTER CALL TO ACTION STATEMENT... The activation of storm spotters, HAM radio operators, and emergency management personnel in support of severe weather operations is not expected through next Saturday. $$ 3 && ...HAZARD LEGEND... *EXCESSIVE HEAT* Extreme...Maximum heat index greater than 110 degrees for 3 or more days in a row and/or air temperatures greater than 107 degrees. Significant...Maximum heat index greater than 110 degrees and/or air temperatures greater than 105 degrees. Elevated...Maximum heat index 105 to 110 degrees and/or air temperatures greater than 103 degrees. Limited...Maximum heat index near 105 degrees and/or air temperatures 100 to 103 degrees. ...USEFUL WEATHER WEB PAGES (URLS)... NWS JAN Home page... www.weather.gov/jan Stay Aware, Stay Safe NWS JAN Briefing Page... www.weather.gov/jan/safe Latest Weather Briefing... www.weather.gov/jan/weather_briefing Tropical page... www.weather.gov/jan/tropical National Hurricane Center Home Page... www.nhc.noaa.gov/ Find NWS JAN on Facebook... www.facebook.com/NWSJacksonMS Follow NWS JAN on Twitter... @NWSJacksonMS Follow NWS JAN on Youtube... www.youtube.com/user/NWSJacksonMiss
URGENT - WEATHER MESSAGE National Weather Service Jackson MS 914 AM CDT Sun Aug 20 2017 ...HEAT ADVISORY IN EFFECT THROUGH THIS AFTERNOON... ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074- 202215- /O.CON.KJAN.HT.Y.0007.000000T0000Z-170821T0000Z/ Ashley-Chicot-Morehouse-West Carroll-East Carroll-Richland- Madison LA-Franklin LA-Catahoula-Tensas-Concordia-Bolivar- Sunflower-Leflore-Grenada-Carroll-Montgomery-Webster-Clay-Lowndes- Choctaw-Oktibbeha-Washington-Humphreys-Holmes-Attala-Winston- Noxubee-Issaquena-Sharkey-Yazoo-Madison MS-Leake-Neshoba-Kemper- Warren-Hinds-Rankin-Scott-Newton-Lauderdale-Claiborne-Copiah- Simpson-Smith-Jasper-Clarke-Jefferson-Adams-Franklin MS-Lincoln- Lawrence-Jefferson Davis-Covington-Jones-Marion-Lamar-Forrest- Including the cities of Crossett, North Crossett, Hamburg, West Crossett, Dermott, Lake Village, Eudora, Bastrop, Oak Grove, Epps, Lake Providence, Rayville, Delhi, Tallulah, Winnsboro, Jonesville, Harrisonburg, Newellton, St. Joseph, Waterproof, Vidalia, Ferriday, West Ferriday, Cleveland, Indianola, Ruleville, Greenwood, Grenada, Vaiden, North Carrollton, Carrollton, Winona, Eupora, Maben, Mathiston, West Point, Columbus, Ackerman, Weir, Starkville, Greenville, Belzoni, Isola, Durant, Tchula, Lexington, Pickens, Goodman, Kosciusko, Louisville, Macon, Brooksville, Mayersville, Rolling Fork, Anguilla, Yazoo City, Ridgeland, Madison, Canton, Carthage, Philadelphia, Pearl River, De Kalb, Scooba, Vicksburg, Jackson, Pearl, Brandon, Richland, Forest, Morton, Newton, Union, Decatur, Conehatta, Meridian, Port Gibson, Crystal Springs, Hazlehurst, Wesson, Magee, Mendenhall, Taylorsville, Raleigh, Bay Springs, Heidelberg, Quitman, Stonewall, Shubuta, Fayette, Natchez, Bude, Roxie, Meadville, Brookhaven, Monticello, New Hebron, Prentiss, Bassfield, Collins, Mount Olive, Laurel, Columbia, West Hattiesburg, Lumberton, Purvis, and Hattiesburg 914 AM CDT Sun Aug 20 2017 ...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING... * TEMPERATURE...High temperatures in the mid 90s with peak afternoon heat index values ranging from 103 to 109 degrees. * IMPACTS...Heat related illnesses may be possible for those outdoors in unshaded areas without proper precautions taken. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take extra precautions, if you work or spend time outside. When possible, reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear light weight and loose fitting clothing when possible and drink plenty of water. To reduce risk during outdoor work, the occupational safety and health administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency, call 9 1 1. A Heat Advisory means that a period of hot temperatures is expected. The combination of hot temperatures and high humidity will combine to create a situation in which heat illnesses are possible. Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.
Hazardous Weather Outlook
Hazardous Weather Outlook National Weather Service Shreveport LA 609 AM CDT Sun Aug 20 2017 ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077- TXZ097-112-126-137-138-150>153-165>167-211100- Sevier-Howard-Little River-Hempstead-Nevada-Miller-Lafayette- Columbia-Union-Caddo-Bossier-Webster-Claiborne-Lincoln-De Soto- Red River-Bienville-Jackson-Ouachita-Sabine-Natchitoches-Winn- Grant-Caldwell-La Salle-McCurtain-Bowie-Cass-Marion-Gregg- Harrison-Rusk-Panola-Nacogdoches-Shelby-Angelina-San Augustine- 609 AM CDT Sun Aug 20 2017 This Hazardous Weather Outlook is for portions of south central Arkansas, southwest Arkansas, north central Louisiana, northwest Louisiana, southeast Oklahoma, east Texas and northeast Texas. .DAY ONE...Today and Tonight... Daytime temperatures in the upper 90s to near 100 degrees will combine with high humidity values today to produce heat index values of 105 to 110 degrees. Therefore, a Heat Advisory is in effect until early this evening. In addition, a couple of isolated thunderstorms are possible, especially south of Interstate 20. No severe weather is expected at this time. .DAYS TWO THROUGH SEVEN...Monday through Saturday... Thunderstorms will remain possible each day through much of the next week. Thunderstorms are expected areawide on Wednesday. Heat index values will continue to range between 105 and 109 degrees across portions of the area through Wednesday. Cooler temperatures and lower heat index values are expected after a cold front moves across the area on Wednesday. Precautions should be taken to prevent heat related injuries. .SPOTTER INFORMATION STATEMENT... Activation of emergency managers, skywarn networks, and amateur radio operators is not anticipated through tonight. $$
URGENT - WEATHER MESSAGE National Weather Service Shreveport LA 353 AM CDT Sun Aug 20 2017 ...Heat Advisory Remains in Effect Today for Southeast Oklahoma, Northwest and North Central Louisiana, Southwest and South Central Arkansas, and parts of East and Northeast Texas... .The combination of high temperatures in the middle and upper nineties along with high humidity will result in heat indices of 105 to 109 degrees from this afternoon through early this evening. ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077- TXZ097-112-126-137-138-150>153-165>167-210000- /O.CON.KSHV.HT.Y.0009.000000T0000Z-170821T0000Z/ Sevier-Howard-Little River-Hempstead-Nevada-Miller-Lafayette- Columbia-Union-Caddo-Bossier-Webster-Claiborne-Lincoln-De Soto- Red River-Bienville-Jackson-Ouachita-Sabine-Natchitoches-Winn- Grant-Caldwell-La Salle-McCurtain-Bowie-Cass-Marion-Gregg- Harrison-Rusk-Panola-Nacogdoches-Shelby-Angelina-San Augustine- Including the cities of De Queen, Nashville, Mineral Springs, Dierks, Ashdown, Hope, Prescott, Texarkana, Stamps, Lewisville, Bradley, Magnolia, El Dorado, Shreveport, Bossier City, Minden, Springhill, Homer, Haynesville, Ruston, Farmerville, Bernice, Mansfield, Stonewall, Logansport, Coushatta, Martin, Arcadia, Ringgold, Gibsland, Jonesboro, Monroe, Many, Zwolle, Pleasant Hill, Natchitoches, Winnfield, Colfax, Montgomery, Dry Prong, Clarks, Grayson, Columbia, Jena, Midway, Olla, Idabel, Broken Bow, Atlanta, Linden, Hughes Springs, Queen City, Jefferson, Longview, Marshall, Henderson, Carthage, Nacogdoches, Center, Lufkin, San Augustine, Hemphill, and Pineland 353 AM CDT Sun Aug 20 2017 ...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING... * EVENT...High pressure aloft across the area will allow for temperatures to climb into the middle to upper nineties. These temperatures along with low level moisture will produce heat indices of 105 to 109 degrees. * TIMING...Heat indices will be near 105 to 109 in the afternoon and early evening before lowering. * IMPACT...Precautions should be taken to prevent heat related illnesses, including limiting outdoor work activities to the morning before temperatures rise and early evening after the readings lower. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take extra precautions if you work or spend time outside. When possible, reschedule strenuous activities to early morning or evening. Take frequent rest breaks in shaded or air conditioned environments. Know the signs and symptoms of heat exhaustion and heat stroke. Wear light weight and loose fitting clothing when possible and drink plenty of water. Heat stroke is an emergency, call 9 1 1. A heat advisory means that a period of hot temperatures is expected. The combination of hot temperatures and high humidity will combine to create a situation in which heat illnesses are possible. Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.