Severe Potential March 2nd/3rd: OV, TN Valley, Mid-South, Deep South, Mid-Atlantic, Carolinas

[Ellinwood]

Where is that profile located I am going to guess the lift is forecasted to be east of that profile...Secondly, you can have all the thermodynamics you want but you need lift over them. East Texas tomorrow is a perfect example of what you're trying to imply for Friday. I saw you imply the same thing for AR a few days back in another thread and the results are the same as I expect for this Friday where the best dynamics are to the west of the lift...if the solution from the 0z models were to verify. I agree with you lots of great ingredients thermodynamically there but they are not coming together with the dynamics...yet.

You, sir, are winning this thread. The wording that has been used for this threat has been excessive... thanks for reeling it back in. Can't disagree with anything you've said up to this point.

[metalicwx366]

So basically people shouldn't be concerned about this threat?? Right? Thats what you are implying.

[Ellinwood]

So basically people shouldn't be concerned about this threat?? Right? Thats what you are implying.

That's not what's being implied at all. What is being discussed is, while a severe weather threat/outbreak is in the forecast, it is not as doom-and-gloom as some of the previous posters have indicated.

[SmokeEater]

Having a big warm sector on models didn't do anything for that non event. And Andy, QV isn't being a jerk, he's trying to explain to you that this possible event is far from being locked up as an outbreak. He's trying to help you, and you just keep rambling on with the GFS this, and the Euro that, and completely ignoring everything he's saying to you.

Link?

Yeah, I've been on a bunch of forums watching this potential show up on the models for several days now, GFS has been the most consistent with the Euro not too far behind. One thing that is definitely likely is that the GoM is going to be in a prime state to supply a solid warm sector for any potential system like the models have been showing

[TheWeatherPimp]

12z NAM continues to look pretty favorable.

[KokomoWX]

SREF getting interested....

[beneficii]

From MEG:

ON THURSDAY NIGHT...THERE ARE SOME MODEL DIFFERENCES THAT BEGIN TO

SHOW UP. THE GFS...CANADIAN...AND EUROPEAN MODELS HAVE A LARGE

SWATH OF PRECIPITATION THAT DEVELOPS ALONG THE WARM FRONT AND NOSE

OF A LOW LEVEL JET. HOWEVER...THE NAM DOES NOT DEVELOP THIS SWATH

OF PRECIP. A COUPLE OF MODELS...THE NAM AND THE EUROPEAN...ALSO

INDICATE SOME CLEARING OF THE CLOUDS ON FRIDAY MORNING...WHICH

WOULD ENHANCE CHANCES FOR SEVERE WEATHER ON FRIDAY AFTERNOON.

EITHER WAY...FRIDAY APPEARS AS THOUGH IT IS THE BEST CHANCE FOR

WIDESPREAD SEVERE WEATHER ACROSS THE ENTIRE MIDSOUTH. MODELS

INDICATE SURFACE CAPE VALUES BETWEEN 1500-2000 J/KG...LIFTED

INDICES OF -6 TO -8...AND MID LEVEL LAPSE RATES FROM 6.5-7.5

C/KM. FOR THE EVENT ON FRIDAY...THE UPPER LEVEL AND SURFACE LOW

PRESSURE SYSTEMS WILL BE LOCATED ACROSS MISSOURI...MUCH FARTHER

SOUTH THAN TUESDAY NIGHTS SYSTEM. SHEAR ALSO LOOKS QUITE

GOOD...HOWEVER SURFACE WINDS...AS INDICATED BY THE MODELS...WILL

BE FROM SOUTHWEST. AT THIS TIME...I WOULD EXPECT A MIXTURE OF

SUPERCELLS AND SEVERE THUNDERSTORM CLUSTERS. IF A SECONDARY LOW

CAN DEVELOP ACROSS NORTHERN ARKANSAS AND WINDS BECOME MORE SOUTH

OR SOUTHEAST THAN SOUTHWEST...THE TORNADO THREAT WOULD BE HIGHER.

REGARDLESS...DAMAGING WINDS AND HAIL ARE LIKELY WITH ANY STORMS

THAT BECOME SEVERE ON FRIDAY.

[beneficii]

That's not what's being implied at all. What is being discussed is, while a severe weather threat/outbreak is in the forecast, it is not as doom-and-gloom as some of the previous posters have indicated.

Who are these previous posters? I do not believe I was involved in doom and gloom predictions.

[janetjanet998]

12z gfs

[Ellinwood]

Who are these previous posters? I do not believe I was involved in doom and gloom predictions.

My apologies... it was really only andyhb who was going overboard. Carry on.

[Cheeznado]

The GFS is interesting to be sure, but some model differences, will be interesting to see the Euro. Not being "doom and gloom", but there is at least a decent shot at a significant tornado event.

On a related note, SPC continues its tendency to be WAY too conservative in their 4-8 day outlooks, They almost never outlook an area if there is any sort of model difference, which is, well, practically always. I this case, there will be severe Friday, excact position not totally known, but come on, take a stand once in a while.

[andyhb]

Having a big warm sector on models didn't do anything for that non event. And Andy, QV isn't being a jerk, he's trying to explain to you that this possible event is far from being locked up as an outbreak. He's trying to help you, and you just keep rambling on with the GFS this, and the Euro that, and completely ignoring everything he's saying to you.

Fair enough, I understand.

[Hoosier]

12z NAM continues to look pretty favorable.

Early look at some forecast soundings across the Ohio Valley are pretty impressive from a shear perspective.

[Bryan Wood]

Early look at some forecast soundings across the Ohio Valley are pretty impressive from a shear perspective.

I bit that hook on last Thursday's "storms" pretty hard. The OH Valley evolution should be interesting. No surprise, diurnal timing and moisture return are big questions up here. NAM has overplayed moisture up here a lot recently.

[Calderon]

The GFS is interesting to be sure, but some model differences, will be interesting to see the Euro. Not being "doom and gloom", but there is at least a decent shot at a significant tornado event.

On a related note, SPC continues its tendency to be WAY too conservative in their 4-8 day outlooks, They almost never outlook an area if there is any sort of model difference, which is, well, practically always. I this case, there will be severe Friday, excact position not totally known, but come on, take a stand once in a while.

this

[Hoosier]

Substantial differences on the 12z runs. GFS has a 983 mb low near Milwaukee at 00z Saturday...meanwhile the GGEM is about 20 mb weaker in Michigan with another low in Texas.

[Stebo]

Substantial differences on the 12z runs. GFS has a 983 mb low near Milwaukee at 00z Saturday...meanwhile the GGEM is about 20 mb weaker in Michigan with another low in Texas.

Canadian is kind of on an island with it's solution and this type of setup where a piece of energy diving into the SW is often incorrectly modeled by the Canadian. The Ukmet is coming in similar to the NAM out to 72hr. By 96hr it has a low NE of the Soo at 984mb

[Stebo]

The GFS is interesting to be sure, but some model differences, will be interesting to see the Euro. Not being "doom and gloom", but there is at least a decent shot at a significant tornado event.

On a related note, SPC continues its tendency to be WAY too conservative in their 4-8 day outlooks, They almost never outlook an area if there is any sort of model difference, which is, well, practically always. I this case, there will be severe Friday, excact position not totally known, but come on, take a stand once in a while.

I agree with this exactly.

[Cheeznado]

The big difference between this system and previous ones this year is the moisture- the first front will probably not even make it to the Gulf, so there should be a very rich airmass to tap once the second low cranks up and draws that air north.

The new Doc has a more positively tlted system than the GFS, which would limit the LL shear a bit due to more SWly surface winds, but still looks like there will be plenty of severe. Stil would not totally rule out a compromise but the GFS does look too strong with the first short wave and too weak with the second one hanging back in the SW.

[wxsmwhrms]

The big difference between this system and previous ones this year is the moisture- the first front will probably not even make it to the Gulf, so there should be a very rich airmass to tap once the second low cranks up and draws that air north.

The new Doc has a more positively tlted system than the GFS, which would limit the LL shear a bit due to more SWly surface winds, but still looks like there will be plenty of severe. Stil would not totally rule out a compromise but the GFS does look too strong with the first short wave and too weak with the second one hanging back in the SW.

Completely agree with this. A compromise seems to have been the way to go the last couple of weeks as the GFS seems to want to overplay the lead waves - and the EC seems to want to overplay the digging waves in the SW. The fact that the UK and Canadian want to play up the trail wave (and the overall pattern along with typically better performance of EC) probably leads to a bit more emphasis on the EC, but would not be surprised to see something kind of in between end up verifying. Certainly looks like lots of severe with this event given the instability available and strength of the system, but how big of a tornado episode it becomes depends on the details which are still quite unclear.

[wxsmwhrms]

HPC perspective...

...TROUGH REACHING THE PACIFIC NORTHWEST LATE TODAY...

PREFERENCE: GFS/ECMWF BLEND

THE GFS AND NAM BOTH LIE WITHIN THE GUIDANCE CONSENSUS WITH

RESPECT TO THE AMPLITUDE/TIMING OF THE TROUGH THROUGH WED MORNING.

BY LATER ON WEDNESDAY INTO THURSDAY SOME DIFFERENCES EMERGE AS THE

FIRST WAVE OF UPPER-LEVEL ENERGY ROUNDS THE BASE OF THE TROUGH AND

EXITS INTO THE HIGH PLAINS. AS THIS OCCURS BY 12Z ON

THURSDAY...THE NAM APPEARS MORE AMPLIFIED WITH THE SHORTWAVE

RELATIVE TO THE GFS AS WELL AS THE NON-NCEP MODELS.

THEREFORE...WILL RECOMMEND A GFS/ECMWF BLEND. CONFIDENCE IS

AVERAGE.

...SHORTWAVE ENTERING PACIFIC NORTHWEST ON THURSDAY...

...SURFACE LOW DEVELOPING ACROSS THE SOUTHERN PLAINS THURSDAY

NIGHT...

PREFERENCE: ECMWF/UKMET BLEND

A SECOND SHORTWAVE MOVES ONSHORE IN THE PAC NORTHWEST EARLY ON

THURSDAY. AS THIS WAVE CROSSES THE ROCKIES THURSDAY NIGHT...A

SURFACE LOW WILL DEVELOP ACROSS THE SOUTHERN PLAINS. AS THE

SURFACE LOW NEARS THE GREAT LAKES BY LATE FRIDAY...THE NAM REMAINS

THE FASTER SOLUTION. BASED ON THE SOLUTION OF THE 12Z

UKMET/ECMWF...THE GFS SOLUTION APPEARS TO ALSO BE AN

OUTLIER...DEEPENING THE SURFACE LOW MORE THAN ANY OTHER GUIDANCE

AND TRACKING THE LOW FARTHER WEST. THE GFS IS THE ONLY MODEL THAT

PHASES THE NORTHERN AND SOUTHERN STREAM SYSTEMS...RESULTING IN THE

SUBSTANTIALLY DEEPER LOW THAT TRACKS FARTHER TO THE WEST. THE

CANADIAN GLBL AMPLIFIES THE UPPER-LEVEL WAVE SUBSTANTIALLY MORE

THAN ANY OTHER PIECE OF GUIDANCE AND HOLDS THE UPPER TROUGH BACK

OVER THE FOUR CORNERS REGION BY FRIDAY EVENING. WILL CONTINUE TO

RECOMMEND A BLEND OF THE ECMWF/ UKMET. CONFIDENCE IS BELOW AVERAGE.

[beneficii]

MEG is impressed with the moisture and the quality of the warm sector, but they stay mum on issues like shear and instability, preferring to defer trying to answer those questions:

THE FRONT SHOULD LIFT BACK TO THE NORTH THURSDAY NIGHT AS ANOTHER

EVEN STRONGER UPPER LEVEL TROUGH APPROACHES FROM THE WEST. SHOWER

AND THUNDERSTORMS SHOULD BREAK OUT AREAWIDE LATER THURSDAY NIGHT

WITH INCREASING LOW LEVEL MOISTURE AND INSTABILITY AS WELL AS

INCREASING WIND SHEAR. A FEW OF THESE STORMS ALONG THE NORTHWARD

SURGING WARM FRONT MAY BECOME SEVERE. THE WARM FRONT SHOULD LIFT

WELL NORTH OF THE FORECAST AREA BY EARLY FRIDAY MORNING WITH THE

ENTIRE REGION WELL ENTRENCHED IN A MOISTURE RICH GULF AIRMASS.

THIS EXPANSIVE WARM SECTOR WILL SET THE STAGE FOR A POTENTIAL

SIGNIFICANT SEVERE WEATHER EVENT FRIDAY INTO FRIDAY NIGHT AS

SURFACE LOW PRESSURE STRENGTHENS AND LIFTS NORTHEAST FROM THE

SOUTHERN PLAINS INTO MISSOURI AND MID LEVEL COOLING OVERSPREADS

THE QUALITY WARM SECTOR. THERE IS STILL A FEW DAYS TO REFINE THE

DETAILS OF THIS EXPECTED SEVERE WEATHER EPISODE.

[ATL_Militarypolice]

BMX AFD:

AT THE SURFACE THE GFS SHOWS VIGOROUS DEEPENING OF THE SURFACE LOW

AS IT MOVES FROM SOUTHERN KANSAS TO THE GREAT LAKES...FROM 995 MB

12Z FRIDAY TO 971 MB 06 Z SATURDAY. THE SEVERE WEATHER THREAT WILL

BE HIGHER IF THIS SOLUTION VERIFIES...BUT IT WILL ALL DEPEND ON THE

EVOLUTION OF THE MID/UPPER LEVEL TROUGH. AN UPPER LEVEL JET MAX WILL

APPROACH FROM THE SOUTHERN PLAINS BY FRIDAY AFTERNOON LEADING TO

DIFFLUENCE ALOFT OVER OUR REGION. AS OPPOSED TO LINEAR FORCING...THE

BROAD NATURE OF THE LARGE SCALE ASCENT ASSOCIATED WITH APPROACHING

JET MAX SUPPORTS THE IDEA OF SUPERCELL DEVELOPMENT BY LATE FRIDAY

AFTERNOON ACROSS MISSISSIPPI AND NORTHWEST ALABAMA. CAPE VALUES OF

1200 TO 1800 J/KG AND WESTERLY 0-6 KM SHEAR OF 65 TO 75 KNOTS

CROSSING THE WARM SECTOR ALSO ARGUES FOR SUPERCELL DEVELOPMENT IN

THE EARLY STAGES OF THIS EVENT. IF A STRONG SURFACE LOW FORMS AS

DEPICTED BY THE GFS...THE RAPID DEEPENING OF THE SURFACE LOW AND

VIGOROUS PRESSURE TROUGH ASSOCIATED WITH THE FRONT WOULD ALLOW FOR

BACKING SURFACE WINDS DURING THE LATE AFTERNOON. 0-1 KM HELICITY

VALUES IN EXCESS OF 400 M2/S2 ARE NOTED ON THE GFS LATE FRIDAY

AFTERNOON ACROSS THE NORTHWEST PART OF THE AREA WHERE SUPERCELL

DEVELOPMENT IS POSSIBLE...AND THIS COULD LEAD TO AN ENHANCED TORNADO

THREAT. STRONG WIND PROFILES WILL ALSO SUPPORT A DAMAGING WIND

THREAT...AND LARGE HAIL WILL ALSO BE POSSIBLE. AT THIS TIME...THE

BEST THREAT APPEARS TO BE ACROSS THE NORTHERN HALF OF THE AREA FOR

FRIDAY AFTERNOON AND EVENING. A TRANSITION TOWARD A SQUALL IS

EXPECTED OVERNIGHT AS THE FORCING BECOMES MORE ASSOCIATED WITH THE

COLD FRONT. HELICITY VALUES MAY REMAIN QUITE HIGH AS A 60 KT LOW

LEVEL JET DEVELOPS AND THIS WOULD SUPPORT A CONTINUING DAMAGING WIND

AND TORNADO THREAT AS THE LINE MOVES ACROSS THE STATE. THE FRONT

SHOULD CLEAR THE AREA BY NOON SATURDAY LEADING TO MUCH DRIER AND

COOLER CONDITIONS AND ENDING THE SEVERE WEATHER THREAT. WITH THIS

SYSTEM STILL 3 DAYS AWAY...THE AFOREMENTIONED POSSIBLE EVOLUTION OF

THIS EVENT IS SUBJECT TO CHANGE.

GRANTHAM/87

[wxsmwhrms]

BMX AFD:

AT THE SURFACE THE GFS SHOWS VIGOROUS DEEPENING OF THE SURFACE LOW

AS IT MOVES FROM SOUTHERN KANSAS TO THE GREAT LAKES...FROM 995 MB

12Z FRIDAY TO 971 MB 06 Z SATURDAY. THE SEVERE WEATHER THREAT WILL

BE HIGHER IF THIS SOLUTION VERIFIES...BUT IT WILL ALL DEPEND ON THE

EVOLUTION OF THE MID/UPPER LEVEL TROUGH. AN UPPER LEVEL JET MAX WILL

APPROACH FROM THE SOUTHERN PLAINS BY FRIDAY AFTERNOON LEADING TO

DIFFLUENCE ALOFT OVER OUR REGION. AS OPPOSED TO LINEAR FORCING...THE

BROAD NATURE OF THE LARGE SCALE ASCENT ASSOCIATED WITH APPROACHING

JET MAX SUPPORTS THE IDEA OF SUPERCELL DEVELOPMENT BY LATE FRIDAY

AFTERNOON ACROSS MISSISSIPPI AND NORTHWEST ALABAMA. CAPE VALUES OF

1200 TO 1800 J/KG AND WESTERLY 0-6 KM SHEAR OF 65 TO 75 KNOTS

CROSSING THE WARM SECTOR ALSO ARGUES FOR SUPERCELL DEVELOPMENT IN

THE EARLY STAGES OF THIS EVENT. IF A STRONG SURFACE LOW FORMS AS

DEPICTED BY THE GFS...THE RAPID DEEPENING OF THE SURFACE LOW AND

VIGOROUS PRESSURE TROUGH ASSOCIATED WITH THE FRONT WOULD ALLOW FOR

BACKING SURFACE WINDS DURING THE LATE AFTERNOON. 0-1 KM HELICITY

VALUES IN EXCESS OF 400 M2/S2 ARE NOTED ON THE GFS LATE FRIDAY

AFTERNOON ACROSS THE NORTHWEST PART OF THE AREA WHERE SUPERCELL

DEVELOPMENT IS POSSIBLE...AND THIS COULD LEAD TO AN ENHANCED TORNADO

THREAT. STRONG WIND PROFILES WILL ALSO SUPPORT A DAMAGING WIND

THREAT...AND LARGE HAIL WILL ALSO BE POSSIBLE. AT THIS TIME...THE

BEST THREAT APPEARS TO BE ACROSS THE NORTHERN HALF OF THE AREA FOR

FRIDAY AFTERNOON AND EVENING. A TRANSITION TOWARD A SQUALL IS

EXPECTED OVERNIGHT AS THE FORCING BECOMES MORE ASSOCIATED WITH THE

COLD FRONT. HELICITY VALUES MAY REMAIN QUITE HIGH AS A 60 KT LOW

LEVEL JET DEVELOPS AND THIS WOULD SUPPORT A CONTINUING DAMAGING WIND

AND TORNADO THREAT AS THE LINE MOVES ACROSS THE STATE. THE FRONT

SHOULD CLEAR THE AREA BY NOON SATURDAY LEADING TO MUCH DRIER AND

COOLER CONDITIONS AND ENDING THE SEVERE WEATHER THREAT. WITH THIS

SYSTEM STILL 3 DAYS AWAY...THE AFOREMENTIONED POSSIBLE EVOLUTION OF

THIS EVENT IS SUBJECT TO CHANGE.

GRANTHAM/87

I agree with BMX at this point, but there is still a fair amount of uncertainty involved with this setup. Agree with the concept that broad forcing could lead to more of a supercellular threat, but if the upper trough lags much more there may not be any forcing of significance to get storms going. None of the models have been having much success in the last few weeks with regard to how much to dig these southern systems. The 18Z GFS dug it more while the NAM (FWIW, which ain't much) dug it less. I wouldn't even completely write off the idea of a secondary low developing somewhere over the mid-South Friday night into Saturday if the southern system can dig and become separated enough. The 18Z GEFS has solutions that pretty much run this whole gamut (including a completely separated and dug in southern stream system), but to be honest seem to favor more of a progressive, less split flow than the EC/UK/Canadian solutions.

My bottom line is that a severe risk seems pretty strong from eastern AR/northern MS N/NE to the Ohio River, with a decent threat south and north of that area depending on the ultimate evolution of the trough. There is still a potential for a higher end tornado event somewhere from the Ohio Valley into the lower MS Valley, but question on details remain. But as Cheeznado mentioned, to me a big difference in this even is the quality warm sector which would enable storms to get going even with more subtle forcing.

[wxsmwhrms]

The 00Z NAM (again FWIW) really digs the SW US system, but goes berzerk with the lead system and setup in W TN/KY/IN/OH. It looks really favorable in those areas for tornadic supercells Friday afternoon and evening - but it's the NAM, of course.

[ohleary]

The GFS is interesting to be sure, but some model differences, will be interesting to see the Euro. Not being "doom and gloom", but there is at least a decent shot at a significant tornado event.

On a related note, SPC continues its tendency to be WAY too conservative in their 4-8 day outlooks, They almost never outlook an area if there is any sort of model difference, which is, well, practically always. I this case, there will be severe Friday, excact position not totally known, but come on, take a stand once in a while.

You would work at SPC before you make a statement like this, if you were a reasonable Met. Describe how the are WAY too conservative, knowing everything they know about their jobs. Thanks in advance.

[ohleary]

The 00Z NAM (again FWIW) really digs the SW US system, but goes berzerk with the lead system and setup in W TN/KY/IN/OH. It looks really favorable in those areas for tornadic supercells Friday afternoon and evening - but it's the NAM, of course.

Curious why you'd post this at all, if you're going to end it with the famous "it's the NAM". If you don't believe it, why post?

[Hoosier]

Curious why you'd post this at all, if you're going to end it with the famous "it's the NAM".  If you don't believe it, why post?

Um, we're discussing this potentially significant severe event, and it's not like the NAM has a solution that is completely out in left field and radically different than what other models have suggested in the past few days. Anyhow, the 00z NAM would suggest a possible enhanced threat near/north of the Ohio River closer to the surface low. It has backed low level flow and strong 0-6 km shear juxtaposed with 1000-1500+ J/kg CAPE.

[Stebo]

Curious why you'd post this at all, if you're going to end it with the famous "it's the NAM". If you don't believe it, why post?

You post something like that because it is a possible solution with respect to the system.

[SmokeEater]

Curious why you'd post this at all, if you're going to end it with the famous "it's the NAM". If you don't believe it, why post?

Do you have anything constructive to add to this severe thread, other then stirring crap up? Thanks in advance.