Historic outbreak Sunday: The aftermath

[WaitingForSiren]

Oh whoops, lol, I confused Kansas City with St Louis. I was about to say, thatd be bad because it looks like St Louis could get hit nicely on Wednesday at least. Never mind what i said earlier.

[jhamps10]

no kidding siren, local TV is painting a picture of severe weather on Wednesday, and this kinda worries me since they usually will NEVER talk like this 4 days out of a severe weather seranio. But having EAX off this week is not good since if a storm develops in say Kansas city moving at say 50 or 60 MPH it wil be in St. Louis in like 3 hours MAX.

[jkt21787]

Now maybe its time to change the name of the thread If you're not sure what I'm talking about, take a look at the 00z models.

Completely trashes the setup, basically. Trough doesn't go negative tilt until very late and strong surface low just can't develop. Its very strung out. At worst its a severe squall line. No longer has a look that is even near a significant severe weather/tornado event.

Nevertheless, its just one run of major change after rather strong consistency. Would like to see the 12z models before really backing off any significant threat.

[jhamps10]

I'd like to see what SPC says in day 3 forcast in a few hours....

Plus the 12Z models should be the kicker.... if it comes back to a strong system, then all bets are still on for severe weather this week. if not, then who knows what's gonna happen.

[wxmann_91]

From outbreak to poof in one run. Was going to do a map but now I think it's not necessary anymore.

[jkt21787]

From outbreak to poof in one run. Was going to do a map but now I think it's not necessary anymore.

Shouldn't jump off the train too fast. There was a problem with the model initialization tonight I've just learned on another board. Impossible to know if it had any impact on how this setup is shown now.

This was a drastic change, which should raise a little suspicsion. Best to wait until the 12z tomorrow.

But I wouldn't be doing maps now tonight, that's for sure.

[Weatherfreak14]

Yeah, could be popping back up in the short term forcasts within a few days, but I think this raises a few suspecions of what is to happen now.

[WaitingForSiren]

The 12z models havent come in yet, but the 06Z GFS shows a storm favorable for a significant severe weather outbreak across the missouri valley still. I think you guys should let the 00z gs go, I think it was just a fluke. And the NAM obviously isnt getting the picture yet. Ill make a graphic for updated severe forecasts later today.

And I dunno what SPC is smoking with their day 3 outlook...that slight risk will DEFINITELY have to moved towards st louis with an eventual upgrade to moderate risk still looking possible if you ask me toward Missouri and arkansas. I think it might be further west now given the westward hike in the models, but either way wednesday and thursday look to be the most active severe days since November.

[jeff]

I am predicting that the models are slightly too fast with the first system...and instead of a Wednesday night/Thursday morning and early afternoon weather maker here in Houston..I am going to predict that the worst comes during the afternoon and evening of Thursday. We'll see though...this is still 4 days out...

SE TX looks quite capped Thursday. May see the tail end of a squall line should the forecast soundings pan out on the GFS.

[WaitingForSiren]

I guess now would be a good time to say "I told you so!". Latest gfs has this thing stronger than ever and a little further north, so a major outbreak sure looks likely. You guys shouldnt have taken that 00z fluke so seriously!

[jhamps10]

I guess now would be a good time to say "I told you so!". Latest gfs has this thing stronger than ever and a little further north, so a major outbreak sure looks likely. You guys shouldnt have taken that 00z fluke so seriously!

Where is your bulls-eye or the highest area in your opinion on this storm system?

[jasons2k]

I am predicting that the models are slightly too fast with the first system...and instead of a Wednesday night/Thursday morning and early afternoon weather maker here in Houston..I am going to predict that the worst comes during the afternoon and evening of Thursday. We'll see though...this is still 4 days out...

SE TX looks quite capped Thursday. May see the tail end of a squall line should the forecast soundings pan out on the GFS.

I agree Jeff, I would love to get in on the action down here, but it looks marginal for us unless the system digs more.

[WaitingForSiren]

Yeah I think Texas will remain capped, Id be a bit surprised if Houstan even sees A storm out of this whole deal. I definitely think Thursday will be a high risk day now, with Wednesday likely being moderate risk. Ill draw up maps once the 18z GFS run loads.

[jkt21787]

Thursday just doesn't look near as impressive to me as once before, even with 12z GFS back to a more acceptable solution (NAM the same as last night). I believe instability will be a major concern now, and most of the NWS offices are starting to back down in their discussions, mentioning a possible severe squall line but not much else. Perhaps some supercells/tornadoes can't be ruled out but I don't see this being a major tornado event any more, just a wind event. IMHO, this event doesn't exceed Moderate risk and may not get to that.

This afternoon's Memphis discussion...
THE 12Z GFS INDICATES STRONGER DYNAMICS WITH A DEEPER 500 MB TROF AND SURFACE SYSTEM. THE SHEAR IS VERY IMPRESSIVE WITH HUGE 0-3KM HELICITY VALUES WHILE THE MUCAPES ARE MARGINAL AT BEST. THIS SOLUTION SEEMS TO POINT TO A LINE OF STRONG TO MARGINALLY SEVERE STORMS MOVING ACRS THE FORECAST AREA DURING THE DAY. THE 12Z NAM ON THE OTHER HAND SHOWS A WEAKER SURFACE AND UPPER SYSTEM WITH MORE IMPRESSIVE INSTABILITY. HOWEVER THE MAX INSTABILITY AND SHEAR VALUES DO NOT LINE UP VERY WELL AND THIS MODEL IS HINTING AT A LINE OF THUNDERSTORMS DEVELOPING WELL IN ADVANCE OF THE FRONT. THE NAM IS ALSO HINTING AT SOME REDEVELOPMENT AS THE 500 MB TROF MOVES OVER THE MID SOUTH DURING THU AFTERNOON AT THE TIME OF BEST INSTABILITY...PERHAPS THERE WOULD BE SOME HAIL WITH THOSE STORMS. WITH THAT BEING SAID ABOUT 12Z MODEL SOLUTIONS...A POTENT SHORTWAVE MOVING ACRS THE REGION WITH THE GULF WIDE OPEN HAS POTENTIAL FOR SEVERE WEATHER. THE CURRENT FORECAST AND HWO HANDLES SITUATION WELL AND WL CONTINUE WITH THAT THINKING UNTIL THE DETAILS BECOME MORE CERTAIN.

[Extremeweatherguy]

I have a feeling that Houston will get some T-storms out of this...here is part of the latest NWS discussion:

LONG ADVERTISED STORM SYSTEM APPROACHES THE AREA FROM
THE WEST ON WEDNESDAY AND MOVES THROUGH THE AREA WEDNESDAY NIGHT AND
VERY EARLY THURSDAY MORNING. WE COULD SEE SOME SHOWERS OR THUNDERSTORMS
DEVELOP ON WEDNESDAY UNDER A STRENGTHENING LOW LEVEL JET. DYNAMICS STILL
LOOK GOOD FOR POSSIBLE SEVERE THUNDERSTORMS LATE WEDNESDAY NIGHT THROUGH
EARLY THURSDAY MORNING AS THIS SYSTEM MOVES ON THROUGH. STRONG STRAIGHT-
LINE WINDS WILL PROBABLY BE THE PRIMARY SEVERE WEATHER THREAT WITH
LOCATIONS UP NORTH (ROUGHLY NORTH OF I-10) AT GREATEST RISK. RAINFALL
AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO AVERAGE AROUND 1/2 INCH OR
LESS DUE TO ITS FAST EASTWARD SPEED.

[WaitingForSiren]

jkt, one thing you should never do in these kind of situations is pay close attention to long range instability forecasts. Major severe weather outbreaks always occur in situations where rapid moisture transpot has occured, and I definitely think that is what will happen. Wednesdays storm should bring up a lot of moisture, then thursdays storm should have plenty to work with. History shows that wind events are rare in March and I dont think this event will be different. I think numerous supercells/line segments will develop thursday evening, with scattered tornadic supercells likely especially in arkansas, kentucky, tennessee and extreme southern illinois.

[jkt21787]

jkt, one thing you should never do in these kind of situations is pay close attention to long range instability forecasts. Major severe weather outbreaks always occur in situations where rapid moisture transpot has occured, and I definitely think that is what will happen. Wednesdays storm should bring up a lot of moisture, then thursdays storm should have plenty to work with. History shows that wind events are rare in March and I dont think this event will be different. I think numerous supercells/line segments will develop thursday evening, with scattered tornadic supercells likely especially in arkansas, kentucky, tennessee and extreme southern illinois.

I've followed the models for many years, so I know that very well.

But when basically all the NWS offices come to the same thinking regarding instability, its hard to completely ignore it. Based on my analysis, instability could be a problem. Not moisture return, mind you. I think 60 degree dewpoints will be plentiful. But clouds/rain from debris from Wed's activity could prevent much instability from developing. But it will be very hard to tell how this will set up until pratically Thursday.

Now, for those unaware, this is why we will need instability in this situation badly, moreso than in a lot of typical events we see. Because of the screaming wind profiles and excessive shear. Excessive shear will tear apart storm updrafts if there is not enough instability to keep updrafts strong and persistent. I've seen it numerous times before, particularly in this region.

Now, why a linear/wind event might dominate is because of the incredible forcing along the front and powerful LLJ which will run parallel to the front. This allows shear vectors to become parallel rather than perpendicular to the front, which favors linear segments heavily. Enough directional shear in the lower level of the atmosphere does exist, however, which may favor potential for supercells ahead of the line if there is not a strong inhibition layer ahead of the forcing along the front, which would prevent development there. Also this could allow for broken areas within the line to quickly develop embedded supercell characterisitcs and drop a tornado.

But in the end instability will determine just how significant this event gets, and this is something which will be rather uncertain until right up until the event.

[jhamps10]

Disclaimer: This is not an offical product of the SPC and should not be refered as such. This is only the opinion of the poster and not of storm2k.org or any professional organization. this may or may not be based on solid meterology findings. for offical info please refer to the SPC and NWS information.



This indeed has the chance to be a major severe weather outbreak after looking at model info from 00Z. Also this looks to be a major flooding threat for some people in low lying areas as some areas could get up to 4" of rainfall.

[therock1811]

I am going to do my first ever video forecast here. It will be posted as soon as I can get it saved.

Disclaimer: This video forecast is NOT an offical product of the SPC and should not be referred to as such. This is only the opinion of the poster and not of storm2k.org or any professional organization. This may or may not be based on solid meteorology findings. For offical info please refer to the SPC and NWS information.

http://jmos21.podomatic.com/

Look for the pic of the thunderbolt!

[jhamps10]

cool, can't wait for it