Wed., 9th of April 08 till Friday 11th outbreak-thread

[Ed Mahmoud]

This is an active hotlink and will change, but that isn't bad, but at 9 am, the warm front is still just North of I-10 from around Waco to near San Angelo.

Where this warm front winds up around 4 or 6 pm CDT, especially near the dry line junction, should be the danger zone for tornadoes, although obviously hail storms North of the front are already in progress.

[CrazyC83]

The elevated cells with the watches seem to be the warm front.

[KWT]

The only problem with the set-up this afternoon is if the convection already im progress doesn't get out of the way by the early afternoon hours, esp given there is quite a large amount of cloud in place presently which will hamper how high the temps will go if it doesn't get a move on by late morning, early afternoon. Something to just keep an eye on.

[RL3AO]

Cloud cover will be something to watch.

[CrazyC83]

I agree about the cloud cover today, and the wind shear isn't as strong it seems as it will be tomorrow (which would allow things to get going from mostly cloudy skies and modest dewpoints) so the clouds need to clear to get convection going.

[6SpeedTA95]

Guys you look at the environment in the tx panhandle that these storms are in and its upper 30's to mid 40*F and the dewpoints are all pretty low. This is a stout system. As it approaches unstable air even moderately unstable air 65*F and dewpoints in the mid/upper 50's we will probably have some pretty good storms.

[RL3AO]

Due points are impressive. 68 in Austin and 71 in Brownsville.

[6SpeedTA95]

The only problem with the set-up this afternoon is if the convection already im progress doesn't get out of the way by the early afternoon hours, esp given there is quite a large amount of cloud in place presently which will hamper how high the temps will go if it doesn't get a move on by late morning, early afternoon. Something to just keep an eye on.

Yeah thats true but this system is looking pretty impressive. It's taking on a decisive negative tilt, that coupled with the jet should keep storm initiation going well into the evening/overnight hours.

As I said earlier the tornadic threat could be limited by the mousture/heating that takes place throughout the day. However, the dynamics are there for severe storms just maybe not substantial tornadoes north of the red river.

The DFW metroplex, however, seems prime for some substantial storms this afternoon.


Guys ft worth texas is 54*F with a dewpoint of 52* this is up from last hour at 51*F and a dewpoint of 48*

[KWT]

Still think we are going to need to remove the cloud cover if we are going to get anything close to what we could do. If the skies do clear even locally then convection could fire up pretty in an explosive manner given the cape on offer.

[CrazyC83]

Wind shear can't be that great if they are forecasting a derecho tonight though...that might be the difference. However, it looks like EVERYTHING comes together tomorrow.

[CrazyC83]

NWS Paducah is holding a conference call at noon CDT (1700 UTC).

[6SpeedTA95]

NWS Paducah is holding a conference call at noon CDT (1700 UTC).

They must be going over some substantial data.

[6SpeedTA95]

Fort Worth 55*F with a Dewpoint of 52*

[Ed Mahmoud]

The elevated storms North of the warm front will just sharpen the warm front up, the place it needs to clear out to maximize tornado potential is along and South of about a MAF-SJT-ACT-LFK line. Surface instability North of the warm front doesn't need to be great, it is the surface instability South of the warm front that feeds the elevated storms North of the front, and the later developing surface based and potentially tornadic storms South of the front.

Low clouds haven't burned off South of the front yet, but San Angelo is in the mid-60s, and Junction and Fort Stockton are in the low 70s.

[6SpeedTA95]

Corsicana just south of DFW is 74*F with a dewpoint of 66*

[Bunkertor]

Fort Worth 55*F with a Dewpoint of 52*

Many soundings in warned area show this tendency. But the Graphs are so weird and i´m slightly confused.

[6SpeedTA95]

NWS norman has the eastern side of the warm front drifting fast north right now.

[CrazyC83]

1630Z coming out: virtually unchanged

[6SpeedTA95]

New outlook from SPC

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1123 AM CDT WED APR 09 2008

VALID 091630Z - 101200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM CENTRAL AND N TX INTO SRN
AND SERN OK...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA
FROM THE TX BIG BEND INTO SRN KS...THE OZARKS AND THE LWR TN
VALLEY...

...SRN PLAINS...

INGREDIENTS ARE QUICKLY COMING INTO PLACE TO SUPPORT A SIGNIFICANT
PERIOD OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE SOUTHERN PLAINS.
IN RESPONSE TO THE APPROACH OF THE DEEPENING COLD TROUGH OVER THE
SWRN U.S...A STRENGTHENING LOW LEVEL JET IS RAPIDLY TRANSPORTING
QUALITY GULF MOISTURE INTO TX AND OK.

STALLED FRONTAL ZONE FROM SRN AR TO SWRN TX WILL RETURN NWD THIS
AFTERNOON POSSIBLY TO RED RIVER VALLEY BY THIS EVENING. WITH
DEWPOINTS RISING THRU THE 60S MLCAPES AOA 2500 J/KG COUPLED WITH
STEEP MID LEVEL LAPSE RATES AND STRENGTHENING DEEP LAYER VEERING
SHEAR PROFILES WILL BE SUPPORTIVE OF TORNADIC SUPERCELLS.

COMPLEX SCENARIO WITH CURRENT ELEVATED SEVERE THREAT SHIFTING NEWD
ACROSS WRN OK/NWRN TX UNDER STRONG THETAE ADVECTION REGIME. WITH
THE WARM FRONT MOVING NWD ACROSS N TX THIS AFTERNOON...AND LARGE
SCALE ASCENT INCREASING WITH APPROACH OF DIFFLUENT UPPER JET AHEAD
OF MAIN TROUGH...NEAR SURFACE BASED SEVERE THUNDERSTORMS EXPECTED TO
DEVELOP BY MID/LATE AFTERNOON. STORMS THAT DEVELOP VICINITY OF THE
WARM FRONT WILL QUICKLY BECOME SUPERCELLS GIVEN THE QUALITY OF THE
AIR MASS AND STRONG DEEP VEERING SHEAR PROFILES.

LARGE HAIL...AND TORNADOES ARE EXPECTED WITH STORMS THAT DEVELOP
VICINITY WARM FRONT THIS AFTERNOON. THE POTENTIAL OF LONG LIVED
SUPERCELLS AND STRONG TORNADOES WILL BE POSSIBLE AS STORMS TRACK
ACROSS N TX INTO SRN OK THIS EVENING VICINITY SURFACE FRONTAL ZONE.

SURFACE LOW DEVELOPS SWRN TX THIS AFTERNOON AND THEN DEEPENS NEWD
INTO OK TONIGHT AS THE INTENSE TROUGH BECOMES NEGATIVELY TILTED AND
MOVES INTO SRN HI PLAINS BY 12Z THU. SEVERE THUNDERSTORMS WILL
REDEVELOP BACK IN TX PANHANDLE AND SWRN TX TO E OF DRY LINE/COLD
FRONT OVERNIGHT. GIVEN THE STRENGTH OF FORCING...A SEVERE SQUALL
LINE WITH ENHANCED WIND DAMAGE THREAT WILL BE MOST LIKELY MODE.
HOWEVER EMBEDDED SUPERCELLS AND TORNADOES ARE ALSO LIKELY AS THE
SHEAR AND INSTABILITY WILL STILL BE MORE THAN SUFFICIENT...EVEN WITH
THE NORMALLY UNFAVORABLE TIME OF DAY.
DURING THE AFTERNOON AND EVENING ADDITIONAL STRONG/SEVERE
THUNDERSTORMS WILL DEVELOP VICINITY FRONTAL ZONE FURTHER E ACROSS
AR/NRN LA. WHILE SHEAR WILL BE MARGINALLY FAVORABLE FOR ORGANIZED
STORMS...MDT INSTABILITY WITH MLCAPES AROUND 2000 J/KG AND STEEP MID
LEVEL LAPSE RATES WILL SUPPORT AT LEAST MULTICELLULAR STORMS WITH
LARGE HAIL POTENTIAL.

..HALES/SMITH.. 04/09/2008

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
CURRENT UTC TIME: 1630Z (11:30AM), RELOAD THIS PAGE TO UPDATE THE TIME

[Ed Mahmoud]

Warm front just passed San Angelo

09 11:51 S 17 G 30 9.00 Mostly Cloudy BKN026 BKN033 76 63 29.72 1004.4
09 10:51 E 8 6.00 Fog/Mist OVC024 65 61 29.75 1006.0

11ºF temp rise in one hour, and skies are clearing.