Severe Threat....TX to MS

[jeff]

Approaching upper level trough coupled with increasing low level moisture and strong surface heating will sit the stage for an active afternoon and evening from E TX into MS or mirroring the SPC mod. risk for Day 1.

Stalled dry line currently W of the I-35 corridor will begin to march east by early afternoon as upper level trough forces surface low pressure to form over NE TX or NW LA. Air mass over E TX and across much of LA will become moderately unstable with CAPE of 1500-2000 J/kg, Li's of -2 to -5 and increasingly steep lapse rates due to mid level cooling.

Isolated to scattered thunderstorms will develop near and ahead of the dry line over E TX during peak heating and track E into LA by mid to late evening. Fairly weak low level shear should negate much of a tornado threat, however a brief event along the surface warm front extending from N LA into N MS is not out of the question. In addition, any meso scale outflow boundaries remaining over MS and AL from overnight convection may locally enhance low level shear.

South toward the coast, the threat will be directly related to inversion intensity. AM soundings show a strong inversion at both KCRP and KLCH. It is questionable as to if this capping can be broken, and the northern extent of this inversion.

Overall threat will transition into a MCS or squall line late this evening over LA and press into MS and AL overnight. Damaging winds and especially large hail will be the main threats. Mod. risk is mainly a reflection of potentially numerous very large hail reports and does not indicate a significant tornado threat at this time.

[Brett Adair]

I agree with this amplifying upper trough things could get nasty later on. Mainly depending on if our airmass has time to recover from these tropical rainfall amounts. I can see the low level jet is increasing again back to the west which is setting the stage for yet another severe event. My current temperature at 9:90 AM is 66.7 degrees and I just got out of the torrential rain. Time to look at Skew-T's and Hodos for the night time stuff.

[Brett Adair]

Currently a developing SFC low over Amarillo, TX (1010mb) is deepening under as the cyclone is growing vertically stacked. Then nose of an 80 KT jet max is currently rounding the base of a slightly negatively tilt trough currently across West TX. Moist advection is currently ongoing in the boundary layer across eastern TX. Td's are rising through the upper 40's and lower 50's at this hour. A TD surge is expected in the next few axis as the main low level jet develops across the region roughly from Tyler, TX to Shreveport, LA. Upper level support will begin to play a role into the mid afternoon hours as divergence fields increase across the Mid South and allow for convective initiation to occur as a weak cap erodes in the area. With SBCAPE values rising to near 1500J/kg (LI's -6 to -8) with VERY steepe lapse rates developing and overspreading, widespread supercell and LEWPing structures are likely. As favorably unstable baroclinic zone develops ahead of main SFC low, with dropping LCL heights and increasing Effective SRH values tornadic potential will increase into the afternoon. A strong tornado or two can't be ruled out across SRN AR/NRN LA/WRN MS into the evening hours. Hail on the order of 3.5" and damaging winds to 80 mph can also be expected.

[CaptinCrunch]

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST OKLAHOMA...NORTHEAST
TEXAS...SOUTHWEST ARKANSAS...NORTHWEST...AND NORTH CENTRAL LOUISIANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT...
THERE IS A MODERATE RISK FOR SEVERE THUNDERSTORMS ACROSS ALL OF
NORTHWEST AND NORTH CENTRAL LOUISIANA...AS WELL AS MOST OF EAST
CENTRAL TEXAS FOR LATE THIS AFTERNOON THROUGH TONIGHT. A FRONTAL
BOUNDARY HAS MOVED THROUGH MUCH OF THE REGION EARLY THIS MORNING...
AND SHOULD STALL ACROSS CENTRAL LOUISIANA INTO DEEP EAST TEXAS BY
LATE MORNING. BY THIS AFTERNOON...A STRONG UPPER LEVEL STORM SYSTEM
WILL MOVE EASTWARD OUT OF NORTHWEST TEXAS. THIS STORM SYSTEM
WILL HELP TO INCREASE SOUTHERLY LOW LEVEL WINDS...SUCH THAT THE
BOUNDARY SHOULD BEGIN TO LIFT SLOWLY NORTHWARD AS A WARM FRONT.
THE BOUNDARY IS EXPECTED TO LIFT AS FAR NORTH AS THE INTERSTATE
20 CORRIDOR OF NORTHEAST TEXAS AND NORTHERN LOUISIANA BY TONIGHT.
A CAPPING INVERSION WILL BE IN PLACE MOST OF THE DAY...LIMITING
THUNDERSTORM DEVELOPMENT UNTIL THE LATE AFTERNOON AND OVERNIGHT
HOURS. SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THIS
NORTHWARD MOVING BOUNDARY...AND THESE STORMS WILL BE CAPABLE OF
PRODUCING VERY LARGE HAIL...DAMAGING WIND GUSTS AND ISOLATED
TORNADOES.

[Portastorm]

Satellite at 12 noon is showing a well-defined trough/dry line from near Del Rio past the western parts of Austin and into the Hill Country.

SPC is suggesting a possible weather watch for our area.

Could be an active afternoon in central Texas.

[sunny]

This just issued for New Orleans from wwltv.com:

A severe thunderstorm watch has been issued for all of Southeast Louisiana until 6 p.m.

[southerngale]

Special Weather Statement

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LAKE CHARLES LA
650 AM CST THU MAR 31 2005

LAZ027>033-041>045-051>055-TXZ180>182-201-215-216-312300-
ACADIA-ALLEN-AVOYELLES-BEAUREGARD-CALCASIEU-CAMERON-EVANGELINE-
HARDIN-IBERIA-JASPER-JEFFERSON-JEFFERSON DAVIS-LAFAYETTE-
LOWER ST. MARTIN-NEWTON-ORANGE-RAPIDES-ST. LANDRY-ST. MARY-TYLER-
UPPER ST. MARTIN-VERMILION-VERNON-
INCLUDING THE CITIES OF...WOODVILLE...PORT ARTHUR...ORANGE...
NEWTON...KOUNTZE...JASPER...BEAUMONT...OBERLIN...ABBEVILLE...
VILLE PLATTE...OPELOUSAS...NEW IBERIA...MORGAN CITY...MARKSVILLE...
LEESVILLE...LAKE CHARLES...LAFAYETTE...JENNINGS...DERIDDER...
CROWLEY...CAMERON AND ALEXANDRIA

...ANOTHER ROUND OF SEVERE WEATHER POSSIBLE LATER TODAY...

SPRING SEVERE WEATHER SEASON CONTINUES TO BE IN FULL FORCE ACROSS
SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA AS ANOTHER ROUND OF SEVERE
WEATHER IS POSSIBLE ACROSS THE REGION LATE THIS AFTERNOON INTO
TONIGHT.

A STRONG UPPER LEVEL STORM SYSTEM WILL PUSH INTO EASTERN TEXAS AND
LOUISIANA LATER TODAY. GULF MOISTURE WILL COMBINE WITH HIGH
TEMPERATURES IN THE 80S TO MAKE THE ATMOSPHERE VERY UNSTABLE.

AS AN AREA OF LOW PRESSURE DEVELOPS IN EASTERN TEXAS...SCATTERED
STRONG TO SEVERE THUNDERSTORMS ARE FORECAST TO DEVELOP ACROSS THE
REGION LATE THIS AFTERNOON. STRONGER STORMS WILL BE CAPABLE OF
PRODUCING LARGE HAIL AND DAMAGING WINDS.

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS
THE AREA OVERNIGHT BEFORE A COLD FRONT USHERS IN COOLER AND DRIER
AIR BY FRIDAY MORNING.

STAY TUNED TO NOAA WEATHER RADIO AND LOCAL MEDIA OUTLETS FOR FURTHER
UPDATES ON THIS DEVELOPING SEVERE WEATHER SITUATION.


$$

SHAMBURGER

Nothing to speak of on radar yet.

[Johnny]

I see that their is a potential for severe storms to pop up in the next hour or two in the Hill Country. This area was not in the slight risk area.


http://www.spc.noaa.gov/products/md/md0458.html

[Huckster]

This just issued for New Orleans from wwltv.com:

A severe thunderstorm watch has been issued for all of Southeast Louisiana until 6 p.m.

Well, it's been two hours since that watch was issued, and there's not much going on. There is a lot of low cloudiness across southern Louisiana and Mississippi, so I think it might be hard to get anything to develop. Fourteen years of weather watching tells me that there's probably a strong cap in place, and at this point, I'd be surprised to see any widespread intense convection until later on. My experience is this, when there are no significant thunderstorms already occuring in southern Louisiana, and unless storms move in from elsewhere (north Louisiana or Texas), these severe weather watches tend to bust. Seems like every year this happens. There's nothing going on and a watch is issued and nothing develops. This especially seems to happen when the Moderate Risk is anywhere near us. Last weekend was barely an exception to this rule. As it was, most of southern Louisiana was spared severe weather, and in fact, even significant rain. But what can you do? If it looks like severe thunderstorms are a possibility, then you've got to issue a watch. That's the only responsible thing to do. Still, my guess is that nothing serious develops actually here in southern Louisiana, at least not until much later, probably after the watch expires. My bet is that if severe thunderstorms happen here with this event, it won't be until later this evening, and the majority of those storms will likely form in Texas and move into my area rather than actually form here.

[jeff]

Air mass over E TX becoming very unstable due to surface heating and advection of cooler mid level temps (2000 J/kg over most of the region). Dry line currently extending from Dallas to Austin to Del Rio with increasing moisture convergence over E TX along and ahead of this feature and surface low over the TX rolling plains. Radar is starting to show blips over Hamilton and Bosque coutnies SW of Dallas where capping is weakest.

Overall feeling with much basing on the RUC is that convection will develop over EC into N TX along the dry line over the next 2-3 hours as strong mid level jet punches in from the west. Severe hail and winds will be the main threats although an isolated tornado cannot be ruled out. Storms will congeal into a line or line segments by late evening as the cold front arrives into the mix and plows E across LA and MS.


Further South:

Capping remains fairly strong over much of SE TX into SC LA where limited Cu development is seen in visble images. Additionally moisture is limited over these regions and generally confined to below 850mb. It may take until late evening when the cold front arrives for enough lift to break the capping. Areas along and south of a line from Brenham TX to Liberty TX to Lake Charles LA and over to New Orleans have a more conditional threat which will be strongly related to cap intensity and when/if it can be overcome.

[PTrackerLA]

A few showers have started to pop but nothing significant as of yet. I wouldn't be surprised to miss the severe weather once again. They have raised our rain chances from 40% to 70% for tonight so we'll see what happens.

[CaptinCrunch]

THIS HAZARDOUS WEATHER OUTLOOK....UPDATE IS FOR SOUTHEAST OKLAHOMA...NORTHEAST
TEXAS...SOUTHWEST ARKANSAS...NORTHWEST...AND NORTH CENTRAL LOUISIANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT...
THERE IS A MODERATE RISK FOR SEVERE THUNDERSTORMS ACROSS ALL OF
NORTHWEST AND NORTH CENTRAL LOUISIANA...AS WELL AS MOST OF EAST
TEXAS...LATE THIS AFTERNOON THROUGH TONIGHT. THERE IS A SLIGHT
RISK OF SEVERE THUNDERSTORMS OVER EXTREME NORTHEAST TEXAS...
EXTREME SOUTHEAST OKLAHOMA...AND SOUTHWEST ARKANSAS...TONIGHT.

A STATIONARY FRONT LOCATED FROM NEAR ALEXANDRIA LOUISIANA...TO
TYLER TEXAS...TO DALLAS...SEPARATED MOIST AIR TO THE SOUTH FROM
DRY AIR TO THE NORTH. THIS FRONT WILL MOVE SLIGHTLY NORTH THIS
AFTERNOON AND EVENING...AHEAD OF AN APPROACHING COLD FRONT...
WHICH WILL MOVE THROUGH THE FOUR STATE AREA TONIGHT. A STRONG UPPER
LEVEL STORM SYSTEM WILL ALSO MOVE EAST TONIGHT ACROSS THE FOUR
STATE AREA...TRIGGERING STRONG TO SEVERE THUNDERSTORMS IN THE MOIST
AIR...ALONG AND SOUTH OF THE WARM FRONT...MAINLY SOUTH OF INTERSTATE
20. ISOLATED SEVERE THUNDERSTORMS...MAINLY PRODUCING HAIL...COULD
ALSO OCCUR NORTH OF THIS FRONTAL BOUNDARY.

SCATTERED SEVERE THUNDERSTORMS ARE EXPECTED TO FORM LATE THIS
AFTERNOON OVER EAST OR NORTHEAST TEXAS...AND MOVE INTO NORTH
LOUISIANA THIS EVENING. THESE THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING VERY LARGE HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY...
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
ACTIVATION OF EMERGENCY MANAGERS...SKYWARN NETWORKS...AND STORM
SPOTTERS...WILL LIKELY BE NEEDED LATE THIS AFTERNOON...THROUGH
TONIGHT.

[Yankeegirl]

Hazardous Weather Outlook

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
328 PM CST THU MAR 31 2005

GMZ330-335-TXZ163-164-176>179-195>200-210>214-226-227-235>238-011300-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-GALVESTON-
GALVESTON BAY-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-
MATAGORDA BAY-MONTGOMERY-POLK-SAN JACINTO-TRINITY-WALKER-WALLER-
WASHINGTON-WHARTON-
328 PM CST THU MAR 31 2005

...A FEW SEVERE THUNDERSTORMS POSSIBLE ACROSS THE NORTHERN HALF OF
SOUTHEAST TEXAS TONIGHT...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST TEXAS.

.DAY ONE...TONIGHT
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT NOW OVER EASTERN
COLORADO WILL MOVE SOUTHEAST AND WILL CROSS SOUTHEAST TEXAS TONIGHT.
THE COLD FRONT WILL COMBINE WITH UNSTABLE ATMOSPHERIC CONDITIONS TO
GENERATE SCATTERED SHOWERS AND THUNDERSTORMS ACROSS EAST TEXAS. SOME
OF THESE THUNDERSTORMS ARE EXPECTED TO DEVELOP SOUTHWARD INTO
SOUTHEAST TEXAS DURING THE EVENING HOURS.

A FEW THUNDERSTORMS MAY BECOME SEVERE MAINLY IN THE AREA NORTH OF A
LINE FROM BRENHAM TO CONROE TO CLEVELAND. THE PRIMARY SEVERE WEATHER
THREAT IS LARGE HAIL WITH A LESSER THREAT OF DAMAGING DOWNBURST WINDS.
THE PRIMARY TIME FRAME FOR THE SEVERE WEATHER THREAT IS FROM 6 PM THIS
EVENING UNTIL 2 AM FRIDAY MORNING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
NO HAZARDOUS WEATHER IS ANTICIPATED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT....
SPOTTER ACTIVATION IS POSSIBLE IN THE NORTHERN COUNTIES OF SOUTHEAST
TEXAS TONIGHT.

Jeff, whats the difference between your locations and these?

Areas along and south of a line from Brenham TX to Liberty TX to Lake Charles LA and over to New Orleans have a more conditional threat which will be strongly related to cap intensity and when/if it can be overcome.

[Yankeegirl]

Im all confused now.... lol...

[CaptinCrunch]

Thunderstorms starting to form along dry line on Parker and Tarrant Co. line. Thunderstorms streaching down to the south into Bosque and Hamilton Co.'s

http://www.srh.weather.gov/fwd/gwarn/nwswarning.html

[jeff]

Hazardous Weather Outlook

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
328 PM CST THU MAR 31 2005

GMZ330-335-TXZ163-164-176>179-195>200-210>214-226-227-235>238-011300-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-GALVESTON-
GALVESTON BAY-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-
MATAGORDA BAY-MONTGOMERY-POLK-SAN JACINTO-TRINITY-WALKER-WALLER-
WASHINGTON-WHARTON-
328 PM CST THU MAR 31 2005

...A FEW SEVERE THUNDERSTORMS POSSIBLE ACROSS THE NORTHERN HALF OF
SOUTHEAST TEXAS TONIGHT...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST TEXAS.

.DAY ONE...TONIGHT
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT NOW OVER EASTERN
COLORADO WILL MOVE SOUTHEAST AND WILL CROSS SOUTHEAST TEXAS TONIGHT.
THE COLD FRONT WILL COMBINE WITH UNSTABLE ATMOSPHERIC CONDITIONS TO
GENERATE SCATTERED SHOWERS AND THUNDERSTORMS ACROSS EAST TEXAS. SOME
OF THESE THUNDERSTORMS ARE EXPECTED TO DEVELOP SOUTHWARD INTO
SOUTHEAST TEXAS DURING THE EVENING HOURS.

A FEW THUNDERSTORMS MAY BECOME SEVERE MAINLY IN THE AREA NORTH OF A
LINE FROM BRENHAM TO CONROE TO CLEVELAND. THE PRIMARY SEVERE WEATHER
THREAT IS LARGE HAIL WITH A LESSER THREAT OF DAMAGING DOWNBURST WINDS.
THE PRIMARY TIME FRAME FOR THE SEVERE WEATHER THREAT IS FROM 6 PM THIS
EVENING UNTIL 2 AM FRIDAY MORNING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
NO HAZARDOUS WEATHER IS ANTICIPATED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT....
SPOTTER ACTIVATION IS POSSIBLE IN THE NORTHERN COUNTIES OF SOUTHEAST
TEXAS TONIGHT.

Jeff, whats the difference between your locations and these?

Areas along and south of a line from Brenham TX to Liberty TX to Lake Charles LA and over to New Orleans have a more conditional threat which will be strongly related to cap intensity and when/if it can be overcome.

My line and NWS's line almost match, I am just a tad further south at Liberty with NWS at Cleveland. Otherwise a line from Brenham to Liberty cuts close to Conroe.

However, given that the SVR watch is north of both lines we could say the threat is more north of a College Station to Huntsville line.

[jeff]

May need a new weather watch south of 115 shortly given rapid thunderstorm development over C TX from N of KSAT to near KAUS.

Main question is how long activity will continue after dark due to weak low level inflow and increasing capping to the east. However, it is interesting to note more vigorous development is taking place south and SW of WW 115 along the C TX dry line.

[Yankeegirl]

OK.. thanks for the amswer Jeff! Im not really too good with where some locations are... So ya think that Hosuton is clear? There are some storms building out by Austin now, which general direction are they moving, and what do we need to keep an eye out for? Thanks so much for your paitence!!!!

[jeff]

OK.. thanks for the amswer Jeff! Im not really too good with where some locations are... So ya think that Hosuton is clear? There are some storms building out by Austin now, which general direction are they moving, and what do we need to keep an eye out for? Thanks so much for your paitence!!!!

We need to watch the storms to the west. My only concern is the weak low level inflow and capping over our region. They may weaken once the sun sets, however they appear to be getting better organized on the latest radar trends.

We will just have to watch this minute by minute. Could see a similar situation like last Friday where a few supercells come plowing at us but weaken as they get into the area. We shall see.

[Yankeegirl]

Your just too cool, Jeff.. Thanks for the responce! We have a baseball game at 8 tonight for my son, thats why I am so full o' questions.. .lol...