Another week of severe weather in the southern plains?

[Beam]

This is unusual to say the least -- MDT on Day 3:



Thursday should be all kinds of fun.

[Bunkertor]

And on Day 2

[RL3AO]

Wow. Day 3 MDT.

[CrazyC83]

I kinda expected that, but that definitely suggests high confidence.

[CrazyC83]

Strongest wording I have EVER seen on a Day 3 outlook:

SPC AC 080742

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0242 AM CDT TUE APR 08 2008

VALID 101200Z - 111200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS THE ARKLATEX/MID SOUTH
INTO PORTIONS OF MO/IL/KY...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE EASTERN PLAINS AND
MISSISSIPPI/OHIO RIVER VALLEYS...

...ARKLATEX/MID SOUTH INTO THE MIDDLE MISSISSIPPI/OHIO VALLEYS...
WIDESPREAD/SIGNIFICANT SEVERE WEATHER IS LIKELY ACROSS PORTIONS OF
THE ARKLATEX/MID SOUTH INTO PORTIONS OF MO/IL/IND THURSDAY AND
THURSDAY NIGHT...INCLUDING DAMAGING WINDS/LARGE HAIL AND
TORNADOES...SOME OF WHICH COULD BE STRONG/LONG-TRACKED. LATEST 00Z
BASED MODEL GUIDANCE CONTINUES TO GRADUALLY CONVERGE ON THE DETAILS
OF THE DEEPENING CYCLONE ACROSS THE NATIONS MID SECTION ON
THURSDAY...ESPECIALLY REFLECTED IN DEEPER ECMWF/GFS SOLUTIONS. WHILE
THE MID/UPPER TROUGH SHIFTS NORTHEASTWARD ACROSS THE CENTRAL
PLAINS...THE CORRESPONDING SURFACE LOW IS EXPECTED TO STEADILY
DEEPEN ACROSS THE CENTRAL PLAINS/CORNBELT.

STRONG/SEVERE STORMS WILL LIKELY BE ONGOING THURSDAY MORNING ACROSS
PORTIONS OF OK/TX INTO MO/KS/AR. WHILE THIS EXPECTED ACTIVITY
COMPLICATES THE MESOSCALE DETAILS THIS FAR OUT...ADDITIONAL SURFACE
BASED/SUPERCELLULAR DEVELOPMENT IS LIKELY IN THE PRE-COLD FRONTAL
WARM SECTOR ACROSS FAR EASTERN OK/ARKLATEX VICINITY AS THE BOUNDARY
LAYER DESTABILIZES BY EARLY AFTERNOON. WITH A WARM FRONT EXPECTED TO
LIFT NORTHWARD FROM OK/AR INTO THE OHIO VALLEY DURING THE
DAY...RAPID DESTABILIZATION IS LIKELY TO OCCUR DURING THE
AFTERNOON/EVENING NORTHWARD ACROSS MO/IL/IND. VERY STRONG
SOUTH-SOUTHWESTERLY WINDS IN THE LOW TO MID TROPOSPHERE...WITH 100+
KT AT 500 MB AND 50-70 KT AT 850 MB...WILL FAVOR BOTH SUPERCELLS
AND THE EVOLUTION OF QUASI-LINEAR BOW ECHOES ACROSS A BROAD PORTION
OF THE ARKLATEX/MID SOUTH NORTHWARD INTO THE MIDDLE MISSISSIPPI/OHIO
VALLEYS. EITHER WITH QUASI-DISCRETE SUPERCELLS OR THE EVENTUAL
DEVELOPMENT OF LEWPS...A HIGH SRH ENVIRONMENT AND MOIST BOUNDARY
LAYER WILL SUPPORT AN APPRECIABLE RISK FOR TORNADOES...SOME OF WHICH
COULD BE STRONG/LONG TRACKED. OTHERWISE...WIDESPREAD DAMAGING WINDS
AND LARGE HAIL ARE LIKELY.

..GUYER.. 04/08/2008

CLICK TO GET WUUS03 PTSDY3 PRODUCT

NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1100Z
CURRENT UTC TIME: 1147Z (7:47AM), RELOAD THIS PAGE TO UPDATE THE TIME

[Bunkertor]

I think Masters is starting on Thursday. Players will face at least gusty winds

[CrazyC83]

This is the 7th time that I am aware of a Day 3 MDT issuance, the others were:

June 10, 2005
January 2, 2006
April 24, 2007
June 6, 2007
June 7, 2007
October 18, 2007

The only one that really verified (a high would have verified) was 10/18/07. Two of them (06/10/05 and 06/06/07) were total busts, and 04/24/07 busted based on placement. The other two verified but were not major outbreaks.

[Ed Mahmoud]

Already looked at tomorrow's severe outbreak, looking at GFS. Thursday afternoon by later in the day, looks like individual cells are starting to form into a solid line, which would reduce tornado potential somewhat. But check out the GFS Memphis sounding. Memphis should be just ahead of the line at 7 pm CDT, and any cells ahead of the main line look like real potential tornado disasters. Fair amount of inhibition predicted, so maybe there won't be many discrete cells ahead of the squall line.



Of course, with 70 knot winds just above the surface, even the non-tornadic t-storms would cause a lot of damage.




The NIU Storm machine Sounder for the WRF only works to 60 hours, but the WRF could be scarier, not showing a solid squall line moving through Arkansas and Missouri towards Tennesee. IE, more discrete cells, with strong pressure gradient meaning lots of wind energy, and a suggestion of storms on the warm front into the Chicago area.

[Bunkertor]

Could the severe weather event starting tomorrow limit the development on thursday ?

[Ed Mahmoud]

It doesn't look like it from looking at the WRF, that the storms near peak heating will be in areas not much affected previously.

[CrazyC83]

Forgotten in everything is Friday (and even Saturday?):

ZCZC SPCSWOD48 ALL
ACUS48 KWNS 080857
SPC AC 080857

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0357 AM CDT TUE APR 08 2008

VALID 111200Z - 161200Z

...DISCUSSION...
AN ACTIVE SEVERE WEATHER PATTERN WILL LIKELY CONTINUE THROUGH AT
LEAST FRIDAY/DAY 4 ACROSS PORTIONS OF THE OHIO VALLEY/TENNESSEE
VALLEY INTO THE CENTRAL GULF COAST STATES. 00Z GFS AND 00Z/PRIOR 12Z
ECMWF GUIDANCE ARE IN RELATIVELY GOOD AGREEMENT THAT THE NEARLY
STACKED CYCLONE WILL CONTINUE TO SHIFT EASTWARD ACROSS THE UPPER
MIDWEST ON FRIDAY. AHEAD OF THE GRADUALLY OCCLUDING COLD FRONT...IT
APPEARS LIKELY THAT VERY STRONG FLOW IN THE LOW TO MID TROPOSPHERE
WILL REMAIN ATOP A MOIST/UNSTABLE BOUNDARY LAYER ACROSS THE OHIO
VALLEY/TENNESSEE VALLEY INTO THE DIXIELAND REGION. ALL SEVERE MODES
APPEAR POSSIBLE INCLUDING A SIGNIFICANT SQUALL
LINE/SUPERCELLS...WITH DAMAGING WINDS/LARGE HAIL AND SOME TORNADOES.

A THREAT FOR AT LEAST SOME SEVERE WEATHER MAY CONTINUE INTO
DAY 5/SATURDAY ACROSS THE EASTERN STATES. HOWEVER...CONSIDERABLE
UNCERTAINLY /ESPECIALLY GIVEN THE POSITIVE TILT NATURE OF THE UPPER
SYSTEM/ PRECLUDES A SEVERE OUTLOOK FOR DAY 5/SATURDAY AND BEYOND.

..GUYER.. 04/08/2008

CLICK TO GET WUUS48 PTSD48 PRODUCT

Could we see a HIGH for Day 2, and/or another MDT for Day 3 (Friday)?

[CrazyC83]

Should this thread be split? Otherwise it should be renamed, as the threat is by no means limited to the Southern Plains.

[Ed Mahmoud]

I've got a couple of pics of the Wichita County funnel clouds, but no Image Shack account.

PM me, and I'll e-mail the pics to anyone who supplies an e-mail address.

[CrazyC83]

I don't think you need an account for ImageShack.

Anyway, I'm not really sensing a tornado outbreak tomorrow - that area has a big history of busts and the synoptics are much more marginal than Thursday (or even Friday).

[Ed Mahmoud]

I don't think you need an account for ImageShack.

Anyway, I'm not really sensing a tornado outbreak tomorrow - that area has a big history of busts and the synoptics are much more marginal than Thursday (or even Friday).

Au contraire, mon frer.

WRF shows storms just starting to pop West of Abilene at 7 pm CDT tomorrow, and reaching Dallas area toward midnight. Also what appears to be a storm near Austin at 4 pm that moves towards CLS by 7 pm, and then apparently dies, probably due to increasing CINH and loss of heating.

The cell near Austin will have almost 3000 J/Kg SBCAPE, and the storms West of ABI will have near 2500 J/Kg SBCAPE, and when they approach Dallas, will have near 1000 Joules/Kg.

Abilene late afternoon sounding


Dallas late night/very early morning sounding



Thursday does look like the more active day, with a squall line with widespread damaging winds, and any cells ahead of the line having an excellent chance of being tornadic.

Memphis sounding Thursday 7 pm CDT just before WRF shows big squall line moving in. Note even with a lack of tornadoes, winds over 70 mph ( near 115 km/hr) are likely.




But tomorrow shouldn't be any slouch either.

[6SpeedTA95]

we get the next day2 in about 2 hours

[Bunkertor]

On behalf of Ed some pics from the Wichita area

[6SpeedTA95]

nice pics

[CrazyC83]

I wonder what it would look like if percentages could be drawn for Day 4?

[rsdoug1981]

Ed or any of you other soundings gurus...

Do the Thursday soundings for the Jackson, MS area look nearly as rough as they do for points to our northwest? NWS Jackson is hyping the event, but they are (wisely) not pinpointing any single part of the CWFA at the moment.