Severe Weather Discussion

Severe Weather Expected in the Southern Plains Today

Fri, 28 Apr 2006 18:24:26 GMT

Severe Weather Discussion for April 28, 2006, from the Vortex100 Storm Chase Page:

Strong shortwave energy moving into an unstabe airmass over the southern plains will trigger the development of severe convection today.

Lifted indices are forecasted to reach the -3 to -7 range from the Texas panhandle and southwestern Oklahoma into south-central Texas by early this evening.
Excellent shear values, strong jet diffluence and increasing lifting will aid in the development of scattered severe thunderstorms in that area, including tornadic supercells, late this afternoon into this evening.

A strong blocking pattern will prevent the upper level trough in the central part of the nation from advancing quickly eastward on Saturday, with the main focus for severe weather moving into the ArkLaTex region.

Southerly winds will continue to draw deep Gulf moisture northward through the day tomorrow, resulting in lifted indices in the -3 to -7 range from eastern Oklahoma and eastern Texas into Arkansas and Louisiana by late in the day.
Strong shear and very good lifting along the advancing dryline and cold front will generate isolated to scattered severe thunderstorms in that area tomorrow afternoon and evening.

Extended Outlook (Days 3 - 5)

The upper level low in the nation's midection will remain fairly stationary on Sunday, with wind fields beginning to weaken through the day. Even so, a combination of good instability, moderate shear and good lifting will likely produce a few isolated severe cells from southeastern Missouri and far southern Illinois into Louisiana and Mississippi Sunday afternoon and evening. Southerly winds will continue to expand the area of strongest instability from the Gulf coast into the mid-Mississippi valley on Monday. A small area from southeastern Missouri, southern Illinois and southwestern Indiana into northern Mississippi will remain under a threat of a isolated severe thunderstorms on Monday despite weakening wind fields and shear. The upper level low will weaken considerably and finally shear eastward on Tuesday as the upper level block erodes, with the best instability limited to the south-central section of the nation. Strong thunderstorms will develop in that warm, moist airmass from central Texas into central and southern Mississippi Tuesday afternoon and evening, but wind fields and upper level dynamics appear too weak to support organized severe thunderstorms.

Severe Weather Likely in Iowa, Missouri and Illinois Later Today

Tue, 18 Apr 2006 16:38:59 GMT

Severe Weather Discussion for April 18, 2006, from the Vortex100 Storm Chase Page:

Strong upper level energy, accompanied by very good diffluence flow aloft, will move into the central section of the nation from the west today, sparking the development of strong convection.

Southerly winds will bring higher dewpoints northward through the day, with lifted indices reaching the -3 to -10 range from central and southern Iowa and northern Missouri into eastern Missouri and central and southern Illinois by this evening.
Strong lifting along and ahead of the cold front and warm front in that area, combined with increasing shear will produce isolated to scattered severe thunderstorms late this afternoon into this evening.

The risk for severe weather is expected to decrease on Wednesday, as a closed low pressure system moves slowly toward the western Great Lakes region.

The main focus for convective development will be along the surface front, stretching from central Texas into northern Tennesse eastward into the Carolinas.
While there will be strong instability along and to the south of that boundary, the best combination of good instability and shear values will likely to restricted to an area from western and central Kentucky into central and eastern Tennessee, where isolated severe thunderstorms will be possible tomorrow afternoon and evening.

Extended Outlook (Days 3 - 5)

Moderate to strong instability will continue along a slow-moving frontal boundary from Kentucky into Texas on Thursday. Weak upper level energy passing along the boundary will produce isolated strong convection, but with poor upper level support and weak shear no organized severe thunderstorms are expected. Good instability will remain in the southern states on Friday, but the best chance of severe thunderstorm development will be associated with a strong shortwave moving along the front in the southern plains. Increasing shear and lifting will produce isolated severe cells from the Texas panhandle into southern Oklahoma and northern Texas Friday afternoon and evening. On Saturday, moderately strong shortwave energy will get kicked eastward into the southern high plains by a new upper level trough moving into the Great Basin. Strong directional shear, good lifting and increasing instability will likely aidin the development of isolated severe thunderstorms from southwestern Kansas into the Texas panhandle late Saturday afternoon and evening.

Meteorologist Robert Lattery
Vortex100@aol.com
http://members.aol.com/vortex100

Severe Weather Unlikely Today

Mon, 10 Apr 2006 15:42:29 GMT

Severe Weather Discussion for April 10, 2006, from the Vortex100 Storm Chase Page:

Generally stable conditions will exist over most of the nation today, precluding the development of significant severe weather.

Minor instability is expected over far southern Florida and in part of Nebraska and South Dakota today.
However, a lack of good lifting and shear in both areas will keep any convective development brief and below severe levels.

Instability is forecasted to increase through the day on Tuesday from the central plains into the upper Midwest ahead of a cold front moving into that area from the Dakotas.

Lifted indices are forecasted to reach the -3 to -7 range from eastern and southern Minnesota and Wisconsin into eastern Kansas and northwestern Missouri by late tomorrow afternoon.
Good shortwave energy, increasing shear and strong lifting in that area will aid in the development of isolated strong to severe thunderstorms late tomorrow afternoon into tomorrow evening.
The best wind fields, surface heating and CAPE values will be over Iowa, northeastern Kansas and northwestern Missouri early tomorrow evening, so that area will likely see the best chance of large hail and damaging winds.

Extended Outlook (Days 3 - 5)

The cold front will push quickly eastward into the eastern Great Lakes area and eastern Ohio Valley on Wednesday. Moderately strong wind fields, good shortwave energy, and marginal instability ahead of the front will generate a few strong cells from southern Ontario and western New York state into Ohio and West Virginia late Wednesday afternoon and evening, but the risk of severe weather will be small. On Thursday, upper level ridging building over most of the nation will likely prevent the development of any organized strong convection, although a few thunderstorms could develop along the stationary front over the Ohio valley. Conditions will not change much on Friday, with low level moisture pooling along the front in the Ohio valley once again. Weak shortwave energy in the west-northwest flow aloft will generate isolated to scattered thunderstorms from southern Illinois to Virginia and North Carolina, but no organized severe weather is expected. Further west, however, strong wind fields and increasing moisture into southern California may be sufficient to produce isolated severe cells in that region as a rather strong upper low moves toward the southwest coast of the nation.

Meteorologist Robert Lattery
Vortex100@aol.com
http://members.aol.com/vortex100

Severe Weather Expected From New York State to the Carolinas Today

Mon, 03 Apr 2006 20:33:04 GMT

Severe Weather Discussion for April 3, 2006, from the Vortex100 Storm Chase Page:

The cold front that helped produce severe weather yesterday will move through the Appalachians to the east coast today, triggering more severe weather, just not as widespread as on Sunday.

Instability will continue to be good in the warm sector as morning convection moves well east of the cold front, with lifted indices reaching the -3 to -8 range from western New York state into the Carolinas.
Strong lifting and moderate to strong shear will generate isolated to scattered severe thunderstorms in that area.
The best chance of tornadic supercells development is expected from central and eastern Virginia and Maryland into eastern North Carolina this evening, where high CAPE values and the strongest shear are expected.

High pressure stretching from Minnesota to the Gulf coast will temporarily end the risk of significant severe weather in the nation on Tuesday.

The best instability tomorrow will be located over the Florida panhandle, where convection will be minimal due to a lack of strong lifting and shear
Elsewhere, a few isolated strong cells may develop over orographically favored areas of California in response to a strong upper level trough and shortwave energy moving toward the west coast.

Extended Outlook (Days 3 - 5)

The strong upper level trough moving onto the west coast on Tuesday will advance into the Great Basin on Wednesday, accompanied by very good shortwave energy and strong jet diffluence from the desert southwest into the central and southern Rockies. In response, surface troughing will develop along the east slopes of the Rockies, with increasing southerly flow in the plains bringing Gulf moisture and warmth rapidly northward. There should be enough shortwave energy ejecting out of the central Rockies to produce isolated severe storms in the unstable, high sheared environment from northeastern Wyoming and western South Dakota into northeastern Colorado and northwestern Kansas Wednesday evening. Another large outbreak of severe thunderstorms and tornadoes is expected in the nation's midsection on Thursday as the upper level trough in the west moves into the plains. Morning convection is expected to clear the warm sector ahead of the dryline and cold front moving into the central part of the nation, allowing good surface heating and strong instability to develop. Strong wind fields at all levels, very good shortwave energy, excellent jet diffluence and very good shear will aid in the development of scattered to numerous severe thunderstorms, including large tornadic supercells, from southeastern South Dakota, Iowa and Illinois into eastern Oklahoma, Arkansas and western Tennessee Thursday afternoon and evening. The upper trough is expected to push eastward and weaken a bit on Friday, but very good jet diffluence and upper level energy will continue with it. Instability and wind fields at all levels will remain moderate to strong ahead of the cold front moving into the Great Lakes and Ohio and Tennessee valleys, sparking the development of scattered severe thunderstorms from Indiana, Ohio and western Pennsylvania into northern Mississippi, northern Alabama, and northern Georgia Friday afternoon and evening.

Meteorologist Robert Lattery
Vortex100@aol.com
http://members.aol.com/vortex100

Severe Thunderstorms and Tornadoes Expected in the Center of the Nation Today

Thu, 30 Mar 2006 14:41:18 GMT

Severe Weather Discussion for March 30, 2006, from the Vortex100 Storm Chase Page:

An outbreak of severe thunderstorms, including tornadic supercells, is expected in the nation's midsection today as a strong upper low rotates northeastward into the central and northern plains.

Dewpoints in the 60's are surging northward through the plains this morning on strong southerly flow, with lifted indices forecasted to reach the -3 to -7 range from southeastern Nebraska and southern Iowa into central and eastern Oklahoma by early this evening.
Lifting and shear will be quite strong in that area resulting in the development of scattered to numerous severe thunderstorms, with concentrated forcing along the cold front expected to produce a violent squall line by later today.
The squall line is forecasted to move rapidly eastward, especially on the north end this evening, bringing damaging winds and hail to the mid-Mississippi valley region and Ozarks by midnight.

The surface low will move into the upper peninsula of Michigan on Friday, as the associated surface front races eastward through the eastern Great Lakes and the Ohio and Tennessee valleys.

Although instability will not be as strong as on Thursday in the area of greatest lift, which is expected to outrun the cold front, strong wind fields and shear will compensate to produce isolated to scattered severe thunderstorms.
The best combination of moderate instability, lifting and strong shear will be in an area from southern Ontario and western New York state into northern Mississippi and northern Alabama tomorrow afternoon and evening.

Extended Outlook (Days 3 - 5)

Warm, moist air will once again surge northward through into the southern and central plains on Saturday as yet another upper level trough moves into the Rockies from the Great Basin. The best likelihood of severe weather will be along and just north of a warm front from northern Oklahoma into Kansas Saturday evening, where strong shear, increasing lifting and very good instability will combine. Sunday will likely see another major severe outbreak of severe thunderstorm and tornadoes in the nation's midsection. A rather large area of moderate to strong instability will surge northward through the plains and into the western Ohio valley. Strong wind fields at all levels, excellent shear and tremendous jet diffluence will aid in the development of scattered to numerous severe thunderstorms, including large tornadic supercells, along the path of an intensifiying surface low and cold front from southern Iowa and Illinois into eastern Oklahoma, Arkansas and northeastern Texas Sunday afternoon and evening. The surface low will continue to strengthen and move into the northern Great Lakes region on Monday, with the cold front advancing into the Appalachians and central Gulf Coast region. Instability and wind fields will be sufficient to produce scattered severe thunderstorms from New York and New Hampshire into western North Carolina and northern Georgia by late in the day.

Meteorologist Robert Lattery
Vortex100@aol.com
http://members.aol.com/vortex100

Severe Thunderstorms Unlikely Today and Monday

Sun, 26 Mar 2006 18:09:25 GMT

Severe Weather Discussion for March 26, 2006, from the Vortex100 Storm Chase Page:

Generally cool and dry conditions over most of the nation will preclude the development of severe thunderstorms over the next couple of days, with best chance of thunderstorms in parts of Texas tomorrow.

Surface low pressure will accompany a strong shortwave as it move from the Rockies today into the central and northern plains on Monday.
Some moisture return into southern and central Texas will combine with relatively strong lifting along a cold front, marginal shear and moderate upper level energy to produce isolated to scattered thunderstorms from central into northeastern Texas by Monday evening.
With the best instability located in southwestern Texas along the Rio Grande, the risk of severe thunderstorm development appears minimal at this time.

Extended Outlook (Days 3 - 5)

More isolated thunderstorms are expected along the frontal boundary stretching from central Texas into central Mississippi on Tuesday. Once again, however, instability and shear will likely be too weak to generate organized severe thunderstorms. Although, strong shear and moderate instability in the central Rio Grande valley Tuesday night could generate thunderstorms with very heavy rain and small hail in that area. On Wednesday, a strong upper level trough will move from the Great Basin into the Rockies, with diffluent flow ahead of it. Strong southerly winds in the plains will bring Gulf moisture and warmth quickly northward through the day, but with the best upper level energy and dynamics remaining to the west of that region, no severe weather is expected. The prospects for severe weather development will increase dramatically on Thursday as the upper level trough in the Rockies, accompanied by very good shortwave energy, moves into the plains. A strong area of surface low pressure will move into central Nebraska by Thursday evening, with a strong cold front front moving into the central high plains and a dryline racing into central Kansas, central Oklahoma and central Texas. Clouds and numerous showers may inhibit some heating in the plains, but strong lifting, excellent shear and moderate to strong instability should generate scattered to numerous severe thunderstorms, including tornadic supercells, from eastern Nebraska and Iowa into central Texas Thursday afternoon and evening.

Meteorologist Robert Lattery
Vortex100@aol.com
http://members.aol.com/vortex100

Very Isolated Strong Thunderstorms Possible in Texas Today

Fri, 17 Mar 2006 17:27:14 GMT

Severe Weather Discussion for March 17, 2006, from the Vortex100 Storm Chase Page:

There will be little risk of significant severe weather in the U.S. today as any good low level moisture and instability is trapped in far southern Texas in the Rio Grande river valley.

Lifted indices are forecasted to range from the -2 to -5 range by late this afternoon in far southern Texas.
However, with the best lifting and shear in the cooler air north of the front in that area, any strong convection will be very isolated at best.

Instability will spread further northward into central Texas on Saturday, as the warm front lifts northward in response to strengthening upper level troughing in the desert southwest.

Lifted indices in the -3 to -7 range are forecasted along and to the south of that front, with a good concentration of higher dewpoints and instability right along the front in central Texas.
Good shortwave energy approaching from the southwest, increasing lifting and excellent shear values will spark the development of isolated to scattered severe thunderstorms along and just to the north of the warm front tomorrow afternoon and evening.

Extended Outlook (Days 3 - 5)

The upper level trough in the desert southwest will make only slow progress eastward on Sunday as upper level energy becomes concentrated in the base of that trough. Meanwhile, increasing southerly flow in the southern plains will bring Gulf moisture through most of Texas and into southwestern Oklahoma. Very good lifting and shear along the warm front and a developing dryline will aid in the development of isolated to scattered severe thunderstorms in western and central Texas and southwestern Okahoma by Sunday evening. On Monday, the upper level trough will move quickly out of the southwestern states into the central and southern plains, accompanied by strong shortwave energy and excellent jet diffluence. As a result, surface low pressure is expected to move into southeastern Oklahoma by late Monday afternoon with a strong dryline punching into central Texas. Strong wind fields, shear and lifting will produce scattered severe thunderstorms, including tornadic supercells, from southeastern Oklahoma and southern Arkansas into central and eastern Texas and Louisana Monday afternoon and evening. The upper level trough is expected to weaken a bit as it races intothe southeastern section of the nation on Tuesday. Even so, there will likely be enough instabilty, strong wind fields and shear to produce isolated severe thunderstorms along and ahead of an advancing cold front from North Carolina into northern Florida on Tuesday.

Meteorologist Robert Lattery
Vortex100@aol.com
http://members.aol.com/vortex100

Severe Thunderstorm and Tornado Outbreak Expected in the Central U.S. Today

Sun, 12 Mar 2006 17:38:13 GMT

Severe Weather Discussion for March 12, 2006, from the Vortex100 Storm Chase Page:

A major severe weather outbreak, including large tornadoes, it expected in the nation's midsection today as a rather potent shortwave progresses from the southern Rockies into the plains and Mississippi river valley.

Surface low pressure will develop and move into north-central Kansas by early this evening, with increasing southerly flow bringing deep Gulf moisture northward ahead of it.
Lifted indices are forecasted to reach the -3 to -8 range from eastern Kansas, Missouri, southern Iowa and Illinois into northeastern Texas and Arkansas by late this afternoon.
Strong shear and pockets of good lifting will result in the development of scattered to numerous severe thunderstorm clusters in that area, including tornadic supercells, late this afternoon into this evening.

The strong surface low will rotate into northern Michigan on Monday, with the associated cold front advancing into the Ohio and Tennessee valleys and the central Gulf coast region.

Despite cloud cover reducing heating ahead of the front, lifted indices are forecasted to reach the -3 to -6 range from far southern Ontario and western New York state into southeastern Louisiana, Mississippi and Alabama by late in the afternoon.
Continued strong winds field, shear, lifting and jet diffluence will generate scattered severe thunderstorms in that area tomorrow afternoon and evening.

Extended Outlook (Days 3 - 5)

The cold front will clear most of the east coast by Tuesday afternoon, with the best upper level support moving into southeastern Canada and the Atlantic Ocean, which will end the risk of significant severe weather over the nation. Good shortwave energy will move back into the central section of the nation on Wednesday, helping to generate a surface low in north-central Kansas by the early evening hours. Southerly winds will being some Gulf moisture into the southern plains, helping to generate a few thunderstorms in eastern Texas by Wednesday evening, but the instability is forecasted to be too weak to support severe convective development. On Thursday, Gulf moisture will continue to move into the northwestern Gulf coast region as a stationary front sets up in that area. Although shear values will not be strong, good lifting along the front and some jet support will generate isolated strong to severe cells from east-central Texas into Louisiana and southwestern Mississippi Thursday afternoon and evening.

Meteorologist Robert Lattery
Vortex100@aol.com
http://members.aol.com/vortex100

Severe Storms Unlikely Today, Better Chance on Saturday

Fri, 10 Mar 2006 17:27:46 GMT

Severe Weather Discussion for March 10, 2006, from the Vortex100 Storm Chase Page:

A weakening cold front has dipped into the deep south as the strong upper level energy that helped produced severe weather in the nation's midsection yesterday moves into southeastern Canada.

There will be a good combination of moderate instability and weak to moderate shear along and south of the front from eastern Texas into Georgia and South Carolina today.
Although a few isolated strong cells are possible in that area, lifting will be minimal, which will limit the development of organized severe thunderstorms.

Strong shortwave energy will move out of the southern Rockies and into central plains and mid-Mississippi valley area by late tomorrow afternoon and evening.

Increasing southerly flow from the Gulf of Mexico will bring good low level moisture and warmth back northward, resulting in lifted indices in the -3 to -7 range from eastern Iowa and Illinois into northeastern Oklahoma and northern Arkansas by late in the day.
Strong jet diffluence and increasing lifting and shear will aid in the development of isolated to scattered severe thunderstorms in that area Saturday afternoon and evening

Extended Outlook (Days 3 - 5)

A significant severe weather outbreak is still expected in the central section of the nation on Sunday, despite indications from the latest NAM model that shortwave energy ejecting out of the southern Rockies will not be as well-organized as forecasted by virtually every other model. Following a consensus from the other models (GFS, ECMWF, UKMET and GEM-Global), a strengthening area of surface low pressure will move into north-central Kansas by the early evening hours, with increasing southerly flow bringing deep moisture back into the east-central plains. Very good instability, strong shear, great jet diffluence and potent areas of lifting will produce scattered to numerous severe thunderstorms, including tornadic supercells, from eastern Kansas, eastern Okahoma and northeastern Texas into Missouri, western Illinois and Arkansas Sunday afternoon and evening. The surface low will continue to strengthen as it moves into the Great Lakes region on Monday, with a strong cold front pushing into the Ohio and Tennessee valleys and the central Gulf coast states. Although cloud cover from overnight and morning convection may reduce surface heating and instability ahead of the cold front, strong shear and lifting will likely compensate to produce scattered severe thunderstorms from Indiana, Ohio and western Pennsylvania into eastern Louisiana, Mississippi and Alabama monday afternoon and evening. The cold front will race onto the east coast by Tuesday afternoon, as the associated surface low moves into Quebec. It appears that the best combination of good instability, shear and lifting will move off the east coast into the western Atlantic during the afternoon and evening hours, reducing the risk of severe weather over the nation.

Meteorologist Robert Lattery
Vortex100@aol.com
http://members.aol.com/vortex100

Severe Thunderstorms Likely in the Mid-South Today

Thu, 09 Mar 2006 19:02:22 GMT

The vortex100 5-Day Severe Weather Discussion has returned after a long hiatus! Thanks to all those who contacted me encouraging me to restart this discussion.

Warm, humid air is surging northward ahead of a strong cold front today, accompanied by a very potent shortwave, moving into the an area from the lower Ohio valley into the central Gulf coast.

Lifted indices are forecasted to reach the -3 to -8 range from southeastern Missouri, far southern Illinois and southwestern Indiana into Louisiana, Mississippi and Alabama by early this evening.
Strong lifting and substantial shear will enhance convective development and the cold front advances eastward.
The strong shortave interacting with this unstable airmass will trigger the development of scattered severe thunderstorms in that area this afternoon and evening.

The strong shortwave will race rapidly northeastward overnight today into Friday and weaken, which will lessen the risk of severe weather development tomorrow.

By late tomorrow afternoon, the cold front will stretch from southern New England into the Tennessee valley westward into Kansas, where it will become a warm front and link up with a developing surface low in eastern Colorado.
The best instability will be pushed southward into the deep south, with lifted indices expected in the -3 to -8 range from South Carolina into eastern Texas.
With only weak lifting and marginal shear forecasted in that area, no significant severe thunderstorm development is expected.

EXTENDED OUTLOOK

The risk for severe weather will increase once again on Saturday as a strong surface low moving into the Upper MIdwest draws Gulf moisture back northward into the lower and mid-Mississippi valley and western Ohio valley. Increasing lifting along the cold front pushing quickly into that area from the west and improving shear in the warm sector will likely generate isolated to scattered severe thunderstorms from Illinois, Indiana and western Ohio into Arkansas and western Tennessee Saturday afternoon and evening. On Sunday, strong shortwave energy is expected to move out of the southern Rockies and into the central plains and Ozarks during the afternoon and evening hours. A strengthen area of surface low pressure in Kansas will increase the moisture and heat return into the east-central plains by late Sunday afternoon, with strong wind fields and shear developing at all levels. Areas of strong lifting in the warm sector will enhance strong convective development, with a widespread outbreak of severe weather, including damaging tornadoes, possible from eastern Kansas, Missouri and central and southern Illinois into eastern Oklahoma, northeastern Texas and Arkansas Sunday afternoon and evening. The surface low will continue to intensify as it moves northeastward on Monday into Great Lakes region. Good lifting and shear along the strong cold accompanying the low will spark the development of scattered severe thunderstorms from Indiana and Ohio into eastern Louisiana, Mississippi, Alabama, and western Georgia.