Heightened severe weather threat Thursday...
Posted: Wed Mar 03, 2004 3:42 pm
The ingredients are coming together for a possible severe weather outbreak across the south central United States in addition to flooding rains later today through Thursday. Areas most likely to see severe thunderstorms will be from southwest and central Texas northeastward through southeast Oklahoma, the ArklaTex region and into portions of Arkansas and Missouri as well. In addition, showers and thunderstorms will be capable of producing torrential rains with 4 inches or more expected in some areas of the south central United States now through Thursday.
The first of this severe weather event will begin later this evening across the Big Bend area and the Rio Grande Valley of southwestern Texas as a upper low situated over the northern Baja now shifts east towards extreme northern Mexico. Ahead of this upper low, a strong feed of subtropical moisture aloft is progged to advect northeast from the subtropical Pacific. At the same time this is happening, southeast surface winds will advect moisture in from the Gulf Of Mexico. This increase in moisture, dynamics, instability, and lift courtesy of a warm front tonight spells trouble overnight with severe thunderstorms likely starting in southwestern Texas. Then the storms will likely shift east towards north central Texas overnight. The main threats tonight will be large hail and damaging winds. However an isolated tornado or two is possible with any supercell that is rooted in the boundary layer given strong sped shear and continued moistening of the boundary layer. Expect heavy rains of 1-3 inches overnight in many places across the south central United States. More additional heavy rain is expected on Thursday as the main episode of this severe weather outbreak evolves.
Hopefully the test tornado drills worked out on Monday across Texas because on Thursday, the real deal in the form of a potentially dangerous severe weather outbreak is likely to materialize. These following communities on Thursday need to be on the lookout for severe weather including potentially strong tornadoes.
In Texas
Austin
Waco
Wichita Falls
Fort Worth
Dallas
Plano
TexArKana
Tyler
The general corridor from from Hill Country of Texas through southeastern Oklahoma and the ArklaTex region is forecast to see a high level of both shear, dynamic forcing, and great instability as a strong uppr low moves east northeast from New Mexico and helps develop a strong cyclogenesis across the central United States. As a result, supercell thunderstorms will likely develop with large hail, damaging winds, and tornadoes expected across north central Texas stretching up into southeast Oklahoma and into southwestern Arkansas. The primary storm type we're looking out for across north central Texas are discrete supercells or possibly supercells embedded within a broken line of severe convection. In any rate, the level of shear in the atmosphere on Thursday will favor a long lived supercell with the potential for a strong tornado. Dallas Fort Worth is right in the middle of this heightened risk. Further south and east from Houston and Beaumont northward could see damaging winds and large hail potential on Thursday afternoon and evening as a broken line of severe thunderstorms could develop potentially down into the Houston area. However the presence of cap or arm air aloft in the southeast portion of Texas should limit the severe potential that far south and east. Take shelter on the lowest floor of your home in an interior room or preferably a basement if you receive either a severe thunderstorm or tornado warning. Severe thunderstorms can spawn tornadoes without warning. Take shelter whenever you get these warnings tomorrow in north Texas.
Another area of focus will be further north from central Arkansas northward into northern Illinois where a lower wind/tornado probability is expected along with large hail potential as surface low pressure morphs during the day across the central plains and heads towards the Quad Cities vicinity. The bigger story along the northern Mississippi River south and westward into central Oklahoma is heavy rain. Flooding is possible with 4" or more of total rainfall accumulation expected to occur. This is over a months worth of rainfall in just 2 days across the south central portion of the United States. If a flood warning is issued and you come across a flooded road, TURN AROUND and DON'T DROWN. Don't drive through flooded roads as the depth of the water on the road is unknown. The road could even be washed out due to flooding. Thus don't take any chances. In addition to that, the potential for river flooding on the northern Mississippi River is there through early next week as river levels could rise to or just above flood stage by early next week. Snow and ice melt combined with warmer temps and possible heavy rain spells trouble for some places along the Mississippi in the form of minor river flooding. All of these developing stories need to be monitored carefully and we'll keep you updated. Be safe everyone.
Jim
The first of this severe weather event will begin later this evening across the Big Bend area and the Rio Grande Valley of southwestern Texas as a upper low situated over the northern Baja now shifts east towards extreme northern Mexico. Ahead of this upper low, a strong feed of subtropical moisture aloft is progged to advect northeast from the subtropical Pacific. At the same time this is happening, southeast surface winds will advect moisture in from the Gulf Of Mexico. This increase in moisture, dynamics, instability, and lift courtesy of a warm front tonight spells trouble overnight with severe thunderstorms likely starting in southwestern Texas. Then the storms will likely shift east towards north central Texas overnight. The main threats tonight will be large hail and damaging winds. However an isolated tornado or two is possible with any supercell that is rooted in the boundary layer given strong sped shear and continued moistening of the boundary layer. Expect heavy rains of 1-3 inches overnight in many places across the south central United States. More additional heavy rain is expected on Thursday as the main episode of this severe weather outbreak evolves.
Hopefully the test tornado drills worked out on Monday across Texas because on Thursday, the real deal in the form of a potentially dangerous severe weather outbreak is likely to materialize. These following communities on Thursday need to be on the lookout for severe weather including potentially strong tornadoes.
In Texas
Austin
Waco
Wichita Falls
Fort Worth
Dallas
Plano
TexArKana
Tyler
The general corridor from from Hill Country of Texas through southeastern Oklahoma and the ArklaTex region is forecast to see a high level of both shear, dynamic forcing, and great instability as a strong uppr low moves east northeast from New Mexico and helps develop a strong cyclogenesis across the central United States. As a result, supercell thunderstorms will likely develop with large hail, damaging winds, and tornadoes expected across north central Texas stretching up into southeast Oklahoma and into southwestern Arkansas. The primary storm type we're looking out for across north central Texas are discrete supercells or possibly supercells embedded within a broken line of severe convection. In any rate, the level of shear in the atmosphere on Thursday will favor a long lived supercell with the potential for a strong tornado. Dallas Fort Worth is right in the middle of this heightened risk. Further south and east from Houston and Beaumont northward could see damaging winds and large hail potential on Thursday afternoon and evening as a broken line of severe thunderstorms could develop potentially down into the Houston area. However the presence of cap or arm air aloft in the southeast portion of Texas should limit the severe potential that far south and east. Take shelter on the lowest floor of your home in an interior room or preferably a basement if you receive either a severe thunderstorm or tornado warning. Severe thunderstorms can spawn tornadoes without warning. Take shelter whenever you get these warnings tomorrow in north Texas.
Another area of focus will be further north from central Arkansas northward into northern Illinois where a lower wind/tornado probability is expected along with large hail potential as surface low pressure morphs during the day across the central plains and heads towards the Quad Cities vicinity. The bigger story along the northern Mississippi River south and westward into central Oklahoma is heavy rain. Flooding is possible with 4" or more of total rainfall accumulation expected to occur. This is over a months worth of rainfall in just 2 days across the south central portion of the United States. If a flood warning is issued and you come across a flooded road, TURN AROUND and DON'T DROWN. Don't drive through flooded roads as the depth of the water on the road is unknown. The road could even be washed out due to flooding. Thus don't take any chances. In addition to that, the potential for river flooding on the northern Mississippi River is there through early next week as river levels could rise to or just above flood stage by early next week. Snow and ice melt combined with warmer temps and possible heavy rain spells trouble for some places along the Mississippi in the form of minor river flooding. All of these developing stories need to be monitored carefully and we'll keep you updated. Be safe everyone.
Jim