Another week of severe weather in the southern plains?

[CrazyC83]

Hatched on the SWODY3. Don't see that everyday.

Especially considering it is not the main threat day.

As for today, it is looking like scattered tornadoes in Oklahoma and large hail, and straight-line winds seem to be tomorrow's main threat at this point.

[Ed Mahmoud]

Re: ABI and DFW areas Hatched on the SWODY3.

Might make Abilene (ABI) my early tornado pick city, very near some kind of surface feature, sort of like a warm front, with a wind shift from Southeast ahead to South behind it, precip just breaking out before 7 pm, and SW winds aloft over South and Southeast winds at the surface.


This image is hot-linked from the PSU E-Wall, and will be useless in 23 hours.


The Utah U Met page is back, but hasn't updated past 3 April 08.

But the NIU page is back, and the forecast sounding for ABI is scary.



Loads of shear at lower levels, instability decent through the entire column, fairly low LFC and cloud bases, this is a pretty spooky sounding, if it verifies, West Central Texas will have some issues.

[CrazyC83]

Thursday is even scarier...I think a Day 3 MDT is a distinct possibility...

[CrazyC83]

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1118 AM CDT MON APR 07 2008

VALID 071630Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SRN AND
CENTRAL PLAINS...

...SYNOPSIS...
BROAD TROUGHING CONTINUES TO EVOLVE OVER THE WESTERN U.S. POTENT
UPPER LOW WILL BE TRACKING NEWD FROM WI TO ERN UP OF MI TODAY AND TO
SERN ONTARIO OVERNIGHT. UPSTREAM LOW AMPLITUDE IMPULSES WILL BE
TRACKING THROUGH DEVELOPING WRN U.S. TROUGH. W/V IMAGERY SUPPORTS
THE NAM BRINGING A S/WV ACROSS CENTRAL/SRN ROCKIES TO HIGH PLAINS BY
THIS EVENING WITH ANOTHER SYSTEM REACHING CENTRAL PAC COAST LATER
TONIGHT.

SURFACE LOW GRADUALLY DEEPENS TX/OK PANHANDLE THIS AFTERNOON IN
RESPONSE TO STRENGTHENING UPSTREAM WESTERLIES AND APPROACHING MID
LEVEL TROUGH. SHALLOW FRONTAL ZONE FROM SRN LA NWWD TO NWRN TX WILL
MIX/LIFT NWD AS A WARM FRONT TODAY IN RESPONSE TO STRENGTHENING SLY
LOW LEVEL JET AND STRONG SURFACE HEATING AS A DRY LINE DEVELOPS IN
SURFACE TROUGH WRN TX.

...SRN/CNTRL PLAINS...
EVOLUTION OF SEVERE THUNDERSTORM POTENTIAL DISCUSSED IN THE 13Z DY1
STILL VALID. A POTENT SUPERCELL ENVIRONMENT IS EXPECTED TO DEVELOP
DURING THE AFTERNOON AS THE COMBINATION OF RAPID DESTABILIZATION AND
EXPANDING HODOGRAPHS VICINITY OF RETURNING WARM FRONT TAKE PLACE.
WITH STEEP/COOL MID LEVEL LAPSE RATES IN PLACE THE SURFACE HEATING
COUPLED WITH LOW LEVEL MOISTURE RETURN WILL INCREASE MLCAPES TO NEAR
2000 J/KG BY LATE AFTERNOON SRN OK INTO N TX E OF DRY LINE.

MODELS IN BASIC AGREEMENT THAT STORMS SHOULD INITIATE BY LATE
AFTERNOON VICINITY LOW LEVEL CONVERGENCE NEAR THE WARM FRONT AS WELL
AS THE DRY LINE WHICH SHOULD EXTEND SWD FROM NEAR WRN OK/TX BORDER.

THE LIMITED LARGE SCALE FORCING BUT WITH FAVORABLE UPPER
DIVERGENCE/LARGE SCALE ASCENT WITH APPROACHING S/WV TROUGH SUPPORTS
DISCRETE STORMS VS A LINEAR MODE.

INITIALLY SUPERCELLS ACCOMPANIED BY VERY LARGE HAIL WILL BE THE
PRIMARY THREAT BY LATER THIS AFTERNOON. HOWEVER TORNADO CONCERN WILL
INCREASE TOWARD EVENING AS LOW LEVEL JET TO 50KT DEVELOPS. WITH GULF
MOISTURE WHICH THIS AFTERNOON WILL STILL BE SOMEWHAT
LIMITED...INCREASES THRU THE NIGHT...SUPERCELLS ARE EXPECTED TO
CONTINUE WELL AFTER DARK. THIS WILL MAINTAIN BOTH A LARGE HAIL AND A
TORNADO THREAT...PARTICULARLY VICINITY OF E/W WARM FRONT ACROSS OK.

GIVEN THE STILL UNCERTAINTY WITH REGARDS TO THE NUMBER OF STORMS AND
THE TIMING OF DEVELOPMENT...THE FORECAST WILL REMAIN A STRONG
SLIGHT...WITH A POTENTIAL UPGRADE TO MDT THIS AFTERNOON.

...ERN LWR MI...
GOOD HEATING OCCURRING ACROSS LOWER MI AHEAD OF STRONG UPPER LOW AND
COLD FRONT. WITH SURFACE TEMPERATURES WARMING INTO 60S AND LOW 40S
DEWPOINTS A MARGINALLY UNSTABLE AIR MASS WILL BE AVAILABLE FOR STORM
INITIATION ALONG COLD FRONT BY EARLY THIS AFTERNOON. STRONG SHEAR
AHEAD OF UPPER LOW SUPPORTS ORGANIZED LOW TOPPED THUNDERSTORM
DEVELOPMENT BY EARLY AFTERNOON. WITH MLCAPES OF 200-400 J/KG PRIMARY
THREAT WILL BE HAIL AND DAMAGING WINDS GIVEN THE STEEP/COOL LAPSE
RATES. SEVERE COVERAGE WILL BE LIMITED BY SMALL TIME AND SPACE
WINDOW AVAILABLE FOR OCCURRENCE AND THE WEAK INSTABILITY.

..HALES/BOTHWELL.. 04/07/2008

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
CURRENT UTC TIME: 1623Z (12:23PM), RELOAD THIS PAGE TO UPDATE THE TIME

[RL3AO]

I'm pretty certain it will be a mdt at 20z.

[Bunkertor]

I'm pretty certain it will be a mdt at 20z.

This is what i thought, when i read this...

A POTENT SUPERCELL ENVIRONMENT IS EXPECTED TO DEVELOP
DURING THE AFTERNOON AS THE COMBINATION OF RAPID DESTABILIZATION AND
EXPANDING HODOGRAPHS VICINITY OF RETURNING WARM FRONT TAKE PLACE.
WITH STEEP/COOL MID LEVEL LAPSE RATES IN PLACE THE SURFACE HEATING
COUPLED WITH LOW LEVEL MOISTURE RETURN WILL INCREASE MLCAPES TO NEAR
2000 J/KG BY LATE AFTERNOON SRN OK INTO N TX E OF DRY LINE.

[Ed Mahmoud]

Wednesday will be a bigger severe day than today, I'm fairly sure. Not sure about a 3 pm CDT update to moderate.

[Bunkertor]

*Sigh* I ´ve not even seen on single bolt this year... *sigh*

[Ed Mahmoud]

The GFS suggests an ugly day Thursday from Arkansas to Illinois.



Note also rainfall prediction for an area where the rivers are still high.

Batesville, AR, I believe the hometown of NASCAR driver Mark Martin. Not a whole lot of instability, but screaming low level winds, even without tornadoes, with winds just above the surface at 50 knots, even a garden variety storm otherwise will have damaging wind gusts.

[RL3AO]

Would you say we have a slight, moderate, or high risk of a high risk day this week?

[CrazyC83]

I wouldn't be surprised to see a MDT at least every day this week through Friday...for different reasons (tomorrow and Friday for wind), today for hail mainly, Wednesday and Thursday for tornadoes - with the best chance of a HIGH being Thursday)

[Bunkertor]

What about this outlook ? Local services seem to have anticipated the 2000z

LOCATION...
THE MODERATE RISK AREA COVERS LOCATIONS TO THE RIGHT OF A LINE
EXTENDING ADA...TO WICHITA FALLS...TO ALTUS...TO CLINTON...TO PERRY.
THIS INCLUDES THE CITIES OF ADA...LAWTON...WICHITA FALLS...
VERNON...ALTUS...WEATHERFORD...OKLAHOMA CITY...AND STILLWATER.

TIMING...
THE MOST LIKELY TIME FOR SEVERE THUNDERSTORMS WILL BE FROM 5 PM THROUGH THE OVERNIGHT HOURS. THE TIME PERIOD OF GREATEST CONCERN IN THE MODERATE RISK AREA IS FROM 6 PM TO MIDNIGHT.

[RL3AO]

The new day 2 outlook expanded the 30% area NE some into Central Illinois.

[CrazyC83]

What about this outlook ? Local services seem to have anticipated the 2000z

LOCATION...
THE MODERATE RISK AREA COVERS LOCATIONS TO THE RIGHT OF A LINE
EXTENDING ADA...TO WICHITA FALLS...TO ALTUS...TO CLINTON...TO PERRY.
THIS INCLUDES THE CITIES OF ADA...LAWTON...WICHITA FALLS...
VERNON...ALTUS...WEATHERFORD...OKLAHOMA CITY...AND STILLWATER.

TIMING...
THE MOST LIKELY TIME FOR SEVERE THUNDERSTORMS WILL BE FROM 5 PM THROUGH THE OVERNIGHT HOURS. THE TIME PERIOD OF GREATEST CONCERN IN THE MODERATE RISK AREA IS FROM 6 PM TO MIDNIGHT.

They must see something the SPC hasn't yet. If the decision is made, I'd expect a mesoscale discussion showing the upgrade to moderate.

[RL3AO]

Isn't the Norman WFO in the same building as the SPC? They probably just went over and asked them.

[6SpeedTA95]

Tonight may get very interesting, wednesday is also looking like a high probability of severe weather.

[6SpeedTA95]

What about this outlook ? Local services seem to have anticipated the 2000z

LOCATION...
THE MODERATE RISK AREA COVERS LOCATIONS TO THE RIGHT OF A LINE
EXTENDING ADA...TO WICHITA FALLS...TO ALTUS...TO CLINTON...TO PERRY.
THIS INCLUDES THE CITIES OF ADA...LAWTON...WICHITA FALLS...
VERNON...ALTUS...WEATHERFORD...OKLAHOMA CITY...AND STILLWATER.

TIMING...
THE MOST LIKELY TIME FOR SEVERE THUNDERSTORMS WILL BE FROM 5 PM THROUGH THE OVERNIGHT HOURS. THE TIME PERIOD OF GREATEST CONCERN IN THE MODERATE RISK AREA IS FROM 6 PM TO MIDNIGHT.

link?

[RL3AO]

The Norman HWO

http://forecast.weather.gov/showsigwx.php?warnzone=OKZ025&warncounty=OKC109&firewxzone=OKZ025&local_place1=5+Miles+ESE+Wheatland+OK&product1=Hazardous+Weather+Outlook

[6SpeedTA95]

I'm curious as to how the MDT will play out, my guess is that it will encompass what is currently the 10% tornado area. With perhaps a mild expansion to the north and east.

[RL3AO]

MESOSCALE DISCUSSION 0576
NWS STORM PREDICTION CENTER NORMAN OK
0205 PM CDT MON APR 07 2008

AREAS AFFECTED...SW OK...NW TX

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 071905Z - 072030Z

SUPERCELL DEVELOPMENT WILL BECOME MORE PROBABLE AFTER 20-21Z...AND A
TORNADO WATCH WILL LIKELY BE NEEDED BY ABOUT 20Z.
ADDITIONALLY...THE 20Z CONVECTIVE OUTLOOK WILL BE UPGRADED TO MDT
RISK FOR THE SW OK/NW TX AREA.

SURFACE OBSERVATIONS AND VISIBLE SATELLITE IMAGERY CONFIRM A
CONTINUED TREND OF LOW-LEVEL WARMING AND GRADUAL MOISTENING FROM NW
TX INTO SW OK...TO THE S OF A SLOW MOVING FRONT NEAR I-40 AND E OF
THE DRYLINE. THE 18Z SOUNDING FROM OUN...AS WELL AS SHORT TERM
MODEL SOUNDINGS...SUGGEST THAT A MIXED BOUNDARY LAYER WITH NEAR 60 F
DEWPOINTS AND SURFACE TEMPERATURES OF 78-80 F WILL MINIMIZE
CONVECTIVE INHIBITION AND CONTRIBUTE TO MLCAPE VALUES OF 2000-2500
J/KG THIS AFTERNOON. THUNDERSTORM INITIATION WILL BECOME MORE
PROBABLE BY 20-21Z...AS EVIDENCED BY THE RECENT ATTEMPT AT DEEP
CONVECTION ALONG THE DRYLINE IN BAYLOR COUNTY TX. SUPERCELLS WILL
BE LIKELY GIVEN THE SUBTLE FORCING...MODERATE INSTABILITY...
EFFECTIVE BULK SHEAR IN EXCESS OF 50 KT...AND EFFECTIVE SRH IN
EXCESS OF 250 M2/S2. THE STRONGEST STORMS WILL BE CAPABLE OF
PRODUCING VERY LARGE HAIL GIVEN THE STEEP MID LEVEL LAPSE
RATES...WHILE LOW-LEVEL MOISTURE/SHEAR SHOULD BE SUFFICIENT FOR A
FEW TORNADOES LATE THIS AFTERNOON/EVENING.

..THOMPSON.. 04/07/2008