Severe threat april 14, Tornado outbreak possible

[tornadotony]

Shear vectors perpendicular to the initiating boundary would suggest discrete cells as well.

At face value, this would be a large event, likely with numerous tornadic supercells from central NE all the way down to OK, ala 4/8/99 shifted W. But I can't buy that yet. Not even close. Models did not handle this past weekend's system all that well.

[OceanStWx]

At face value, this would be a large event, likely with numerous tornadic supercells from central NE all the way down to OK, ala 4/8/99 shifted W. But I can't buy that yet. Not even close. Models did not handle this past weekend's system all that well.

Of course, even with a perfectly consistent forecast from the models much of it will come down to mesoscale intricacies. Like you said, all we're really doing is taking things at face value right now, which should always be taken with a grain of salt.

[baroclinic_instability]

This is an interesting topic to think about. To put it succinctly, from my experience, the intensification rate of the surface low is pretty irrelevant to the severity of the severe weather/tornado outbreak, and it's something that I rarely take into consideration. The main thing I look at (in forecast mode) is if there's superposition of parameters (CAPE, 0-6 km shear, helicity, etc.) over a large enough region. Obviously it's more complicated than that...there's the cap strength, mesoscale boundaries, storm mode, etc, but generally speaking you can get this superposition irrespective of whether the system is intensifying or not. I can name several examples of systems that were filling in at the time of the outbreak off the top of my head: 4/10/09, 3/15/08, even the Super Outbreak I believe featured a steady-state surface low. One could even make the argument that a rapidly deepening low is a bad sign because there's too much forcing, although this would have to be evaluated on a case-by-case basis.

Now, if you were to take all the major outbreaks and analyze the min SLP tendency of the low during the outbreak, I would guess that you'd find that on average, the low was intensifying at the time. However, this probably has more to do with the cyclogenesis maximum in the lee of the Rockies, and/or the fact that most major tornado outbreaks are associated with large synoptic scale troughs that generate significant surface cyclones (although most don't bomb out).

My philosophy is best illustrated in this particular case as: I'm pretty impressed with this setup overall, but it isn't because of the bombing of the low per se, however meteorologically-impressive it is.

I guess I meant how certain parameters can often be underestimated--much the same way big winter storms bombing out can be grossly underestimated (think the Boxing Day Storm and Groundhogs Blizzard). The highly non-linear development also seems to often times support extreme supercellular development which may be supportive of the highly non-linear pressure perturbations in the storms themselves. Yes the scales don't match up (and even the physical processes)--hence why I mentioned "it seems" to be that way. But yeah I see your point--it just seems to be the case after watching weather events over the years. We are both well aware reality doesn't always match up with perceptions though.

[OceanStWx]

I guess I meant how certain parameters can often be underestimated--much the same way big winter storms bombing out can be grossly underestimated (think the Boxing Day Storm and Groundhogs Blizzard). The highly non-linear development also seems to often times support extreme supercellular development which may be supportive of the highly non-linear pressure perturbations in the storms themselves. Yes the scales don't match up (and even the physical processes)--hence why I mentioned "it seems" to be that way. But yeah I see your point--it just seems to be the case after watching weather events over the years. We are both well aware reality doesn't always match up with perceptions.

We do know that this rapid development would induce a large ageostrophic response from the atmosphere, resulting in more backed surface winds. That in and of itself would promote longer lived supercells.

[brettjrob]

I don't see a major threat for a squall line with this--at least not early on. The moderately curved hodographs near the front as well as strong low level helicity values would be indicative of potentially semi discrete and large supercells even in the presence of not so impressive CAPE values. The SW flow aloft and strongly backed low level wind fields owing to the rapid height falls as the storms turn NE would suggest potential for large dominant right movers as they move into a low level vorticity rich environment with somewhat low LCL's. I don't know if there has been studies or something--but I can't stress it enough--these tanking lows almost always support rather large and at least semi discrete dominant supercells and are often under-estimated events if one looks at severe parameters alone. These non-linear synoptic bombing events--just as they can create extreme winter weather--seem to support the development of extreme convection in the form of very well developed supercells. The jet pattern aloft and associated jet circulation are highly favorable. I would be interested in what Tony and the other severe guys think.

FWIW, I've heard a few other chasers mention their affinity for deepening surface lows at peak heating. In my (limited) experience, it's not a prerequisite for an outbreak by any means, but it can be the catalyst for a substantially overperforming event when it does happen. At the risk of stating the obvious, the rapid last-minute moisture return and strong backing of low-level flow favored by such a scenario is usually quite helpful.

[baroclinic_instability]

We do know that this rapid development would induce a large ageostrophic response from the atmosphere, resulting in more backed surface winds. That in and of itself would promote longer lived supercells.

I think you just said it better right there than my silly post, lol. But yeah you are right. The significant ageostrophic response can be grossly underestimated by some guidance--and sometimes this is why the individual deterministic models can be much more indicative/skillful of potential as opposed to SREF/ensembles where the small scale perturbations are canceled out.

[baroclinic_instability]

FWIW, I've heard a few other chasers mention their affinity for deepening surface lows at peak heating. In my (limited) experience, it's not a prerequisite for an outbreak by any means, but it can be the catalyst for a substantially overperforming event when it does happen. At the risk of stating the obvious, the rapid last-minute moisture return and strong backing of low-level flow favored by such a scenario is usually quite helpful.

I agree--I am basing my experiences on 4 years of forecasting in the private sector--which is pretty piddly in the big scheme. I think you and Ocean nailed it though with the ageostrophic flow response/backed low level flow as well as the feedback/cascade effect in self developing storms.

[OceanStWx]

I think you just said it better right there than my silly post, lol. But yeah you are right. The significant ageostrophic response can be grossly underestimated by some guidance--and sometimes this is why the individual deterministic models can be much more indicative/skillful of potential as opposed to SREF/ensembles where the small scale perturbations are canceled out.

As a for instance, the 12z NAM has a 925 mb ageostrophic wind component due east at 30 kts over eastern Oklahoma. The 12z GFS isn't too far off, with 25 kts of east northeast flow at 925 mb. With the geostrophic component around 45 kts from the southwest, this yields a forecast wind speed at 925 around 35 to 40 kts from the south southeast.

So for those of you who don't completely grasp the concept, the ageostrophic component of the wind is the one that crosses lines of constant height, while geostrophic is parallel. The "true" wind would then fall somewhere in between. In this case, the ageostrophic wind being from the east or northeast is helping to back the "true" wind in the lower levels as air rushes into the rapidly developing low pressure.

[OceanStWx]

Probably another thing to mindful of is that a closing 500 mb low with below normal 500 temps will not require the same quantity of moisture return to produce adequate instability.

[janetjanet998]

Kansas city mentions a good point which could be very dangerous

Tornadic supercells may continue after dark and if they form early in the afternoon then we could have hours and hours of them well into the night..this could lead to a high number of tornadoes

I believe low topped mini supercells storms will start to form by early afternoon over S nebraska (see my previous post about arcs of storms forming) which they have historicly in set ups like this

. THREAT WILL EXIST FOR

DAMAGING WINDS AND HAIL WITH THIS ACTIVITY. WILL ALSO NEED TO WATCH

NOCTURNAL TORNADO THREAT AS MODELS ARE NOT INDICATING MUCH OF A

NOCTURNAL INVERSION SETTING UP WHICH MAINTAINS 0-3 KM CAPE IN THE

100-250 J/KG RANGE AFTER 00Z. THIS COMBINED WITH RAPIDLY INCREASING

0-1 KM SHEAR AND LOWERING LCL HEIGHTS COULD BE FAVORABLE FOR

TORNADOES IN THE 00Z-04Z TIME FRAME AS COLD FRONT MOVES INTO THE

WESTERN CWA.

[janetjanet998]

I have been following severe weather outbreaks for 20 years and in these cases, as others have mentioned, systems like this are oftern under forecast...if the models are correct this could be huge

in the past local NWS's and even SPC have underestimated events like this i think due to lack of experience and younger forecasters using "text book" (ie by the books or what they learned in college) knowledge

[OceanStWx]

Kansas city mentions a good point which could be very dangerous

Tornadic supercells may continue after dark and if they form early in the afternoon then we could have hours and hours of them well into the night..this could lead to a high number of tornadoes

I believe low topped mini supercells storms will start to form by early afternoon over S nebraska (see my previous post about arcs of storms forming) which they have historicly in set ups like this

. THREAT WILL EXIST FOR

DAMAGING WINDS AND HAIL WITH THIS ACTIVITY. WILL ALSO NEED TO WATCH

NOCTURNAL TORNADO THREAT AS MODELS ARE NOT INDICATING MUCH OF A

NOCTURNAL INVERSION SETTING UP WHICH MAINTAINS 0-3 KM CAPE IN THE

100-250 J/KG RANGE AFTER 00Z. THIS COMBINED WITH RAPIDLY INCREASING

0-1 KM SHEAR AND LOWERING LCL HEIGHTS COULD BE FAVORABLE FOR

TORNADOES IN THE 00Z-04Z TIME FRAME AS COLD FRONT MOVES INTO THE

WESTERN CWA.

Good point from EAX. Both the NAM and GFS continue to forecast at least marginal low level thetae lapse rates even until 06z Friday. And the GFS has a ribbon of 0-3km CAPE AOB 100 J/kg at 06z arcing from St. Joseph to Springfield.

[csnavywx]

Good point from EAX. Both the NAM and GFS continue to forecast at least marginal low level thetae lapse rates even until 06z Friday. And the GFS has a ribbon of 0-3km CAPE AOB 100 J/kg at 06z arcing from St. Joseph to Springfield.

This might also be a good time to remind people to use virtual temperature corrections for their sounding analyses. It can be a source of substantial CAPE calculation errors at lower values.

And agree with the isallobaric wind response causing backing winds with a bombing low like that. Some perfect examples of that with the very powerful systems we had in Oct, Dec, and Feb.

[CUmet]

Probably another thing to mindful of is that a closing 500 mb low with below normal 500 temps will not require the same quantity of moisture return to produce adequate instability.

This is one very notable aspect of flatter troughs like this one...they always come in with colder mid-level temps. The overamplified ones tend to draw in warm mid-level temps over the warm sector, which is one reason why I don't like those so much.

[thewxmann]

All in all, everything looks decent except for the LCL heights. Regardless of how this turns out, I'm just going to be glad capping, EML, and moisture mixing issues won't be as big as a factor this goaround. Negative tilt FTW!

[OceanStWx]

Just doing some sounding analysis at 00z Friday (near Tulsa), and the GFS actually has the better turning in the lowest kilometer. A surface wind of 165/15kts and 210/40kts at 1 km. The NAM is relatively unidirectional, though as we discussed the rapid intensification should lend itself to more backed surface winds. In either case (since the NAM quickly turns the winds above there), this leads to 300-400 m²/s² helicity in the 0-3km layer.

As somebody mentioned above, LCLs are a bit high (around 4kft), with a surface T/T_d of 75/60. But the favorable lapse rates aloft still yield over 2000 J/kg CAPE with breakable (NAM) to no (GFS) CIN. That difference mostly comes from the NAM being slightly slower, with convection likely ongoing at the GFS point sounding location. Therefore, I modified the GFS sounding to be more reflective of initiation.

[ATL_Militarypolice]

This might also be a good time to remind people to use virtual temperature corrections for their sounding analyses. It can be a source of substantial CAPE calculation errors at lower values.

And agree with the isallobaric wind response causing backing winds with a bombing low like that. Some perfect examples of that with the very powerful systems we had in Oct, Dec, and Feb.

If you don't mind me asking, what is the virtual temperature corrections you are referring to, and how do I do this when looking at sounding analysis?

[upsloper]

If you don't mind me asking, what is the virtual temperature corrections you are referring to, and how do I do this when looking at sounding analysis?

Since water vapor is less dense than dry air, the higher the moisture content, the more buoyant the air is. Virtual temperature compensates for this fact.

When you look at a sounding, just use virtual temp as your regular temp, finding your LFC and then your CAPE.

Edit: Good link on soundings if you need it: http://www.cs.ubc.ca...ew-T-Manual.pdf

[Chinook]

Check out the similarity to February 26 1958 negatively tilted bomb storm. This is not to say that a storm in February will do the same things as a storm in April. Note 1957 to 1958 was a strong El Nino.

http://journals.amet...g/toc/mwre/86/2

"A CLASSIC EXAMPLE OF RAPID CYCLOGENESIS IN THE MIDWEST, FEBRUARY 25–28, 1958"

"On the night of February 26, 1958 four tornadoes in Mississippi caused 12 deaths and 80 injuries; although no large towns were hit property damage was believed to be near one million dollars."

http://www.greatlake...8_500_loop1.gif

http://www.greatlake...58_sfc_loop.gif

[OceanStWx]

Another thing that is pretty apparent with the models right now, is that a lot (in fact nearly half) of the CAPE is forecast to be between -10 and -30 C (the hail growth zone). That will lend itself to strong updrafts in that zone and large hail. The -20 C height is forecast to be around 21kft and the 50 dBZ heights for 1" hail will be around 29kft. Those heights should be fairly easy to achieve with updrafts pushing 45kft.

Also, during the event you can keep an eye on the 65 dBZ mark. Generally speaking getting 65 dBZ to the freezing level (11.5kft) results in severe hail, while getting it to 30kft results in baseball size hail.

[ATL_Militarypolice]

Since water vapor is less dense than dry air, the higher the moisture content, the more buoyant the air is. Virtual temperature compensates for this fact.

When you look at a sounding, just use virtual temp as your regular temp, finding your LFC and then your CAPE.

Edit: Good link on soundings if you need it: http://www.cs.ubc.ca...ew-T-Manual.pdf

Thanks

[JoMo]

I'm not a fan of nighttime tornadoes. Storms look to arrive here around midnight Thursday (on the 00z NAM), LCL's are low, helicity is pretty crazy and instability is still around. Still plenty of time for it to change tho.

[brettjrob]

I'm not a fan of nighttime tornadoes. Storms look to arrive here around midnight Thursday (on the 00z NAM), LCL's are low, helicity is pretty crazy and instability is still around. Still plenty of time for it to change tho.

The NAM seems to be trending toward a slightly narrower instability axis that also sets up farther west than earlier runs suggested. If you take the new run verbatim, I'm not sure that JLN ever destabilizes enough to have serious problems. On the other hand, I've noticed your area is notorious for overperforming events with apparently-questionable low-level moisture, particularly after dark. The hodographs are indeed rather crazy across the tri-state region.

[JoMo]

Day 2 Moderate.

[SmokeEater]

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1258 AM CDT WED APR 13 2011

VALID 141200Z - 151200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SE KS...ERN

OK...FAR SW MO AND FAR NW AR...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL

PLAINS...SRN PLAINS...MID-MO VALLEY...OZARKS AND ARKLATEX...

...REGIONAL OUTBREAK OF SEVERE STORMS AND POSSIBLY TORNADOES ACROSS

PARTS OF THE SRN AND CNTRL PLAINS THURSDAY AFTERNOON AND EVENING...

...SRN PLAINS/CNTRL PLAINS/OZARKS/MID-MO VALLEY...

AN IMPRESSIVE NEGATIVELY-TILTED UPPER-LEVEL TROUGH IS FORECAST TO

CLOSE OFF OVER THE CNTRL HIGH PLAINS THURSDAY. THE EXIT REGION OF A

70 TO 80 KT MID-LEVEL JET ROUNDING THE BASE OF THE TROUGH WILL

CREATE STRONG DEEP LAYER SHEAR PROFILES ACROSS THE REGION CREATING

AN ENVIRONMENT FAVORABLE FOR SEVERE STORM DEVELOPMENT. AT THE

SFC...A WELL-DEVELOPED LOW IS FORECAST TO DEEPEN QUICKLY ACROSS

CNTRL KS AT MIDDAY MOVING NWD INTO NEB. THUNDERSTORM INITIATION

SHOULD FIRST OCCUR NEAR AND TO THE NORTH OF THE SFC LOW DURING THE

AFTERNOON WHERE STRONG LOW-LEVEL CONVERGENCE AND COLD TEMPS ALOFT

SHOULD RESULT IN A LARGE HAIL THREAT. THE MODELS ARE CONSISTENT

DEVELOPING STRONG CONVECTION DURING THE LATE AFTERNOON SEWD INTO

CNTRL TO ERN KS AND ECNTRL OK ALONG THE WRN EDGE OF AN AXIS OF

MODERATE INSTABILITY. THE STORMS SHOULD INITIATE JUST TO THE EAST OF

A DRYLINE ORIENTED NORTH TO SOUTH ALONG THE I-35 CORRIDOR.

FORECAST SOUNDINGS ALONG THE INSTABILITY AXIS AT 00Z FRIDAY SHOW

MLCAPE VALUES FROM 1500 J/KG IN ECNTRL KS TO 2500 TO 3000 J/KG IN

ECNTRL OK. THIS COMBINED WITH 0-6 KM SHEAR VALUES OF 50 TO 65 KT

WILL CREATE A THERMODYNAMIC AND SHEAR ENVIRONMENT FAVORABLE FOR

SUPERCELLS AND LARGE HAIL ESPECIALLY ACROSS THE MODERATE RISK AREA

IN SE KS...ERN OK...FAR NW AR AND FAR SW MO. THE GREATEST SEVERE

THREAT COVERAGE SHOULD OCCUR ON THE NOSE OF A PLUME OF STEEP

MID-LEVEL LAPSE RATES WHICH COMBINED WITH THE MODERATE INSTABILITY

AND STRONG DEEP LAYER SHEAR WILL BE FAVORABLE FOR VERY LARGE HAIL

WITH THE MORE DOMINANT SUPERCELLS. TORNADOES WILL ALSO BE POSSIBLE

ESPECIALLY AS THE LOW-LEVEL JET STRENGTHENS DURING THE EARLY

EVENING. FORECAST SOUNDINGS IN ERN OK FROM 00Z TO 03Z SHOW 0-3 KM

STORM RELATIVELY HELICITIES OF 350 TO 450 M2/S2 WHICH WILL MAKE AN

ISOLATED THREAT FOR STRONG TORNADOES POSSIBLE. HOWEVER...THIS THREAT

SHOULD BE CONDITIONAL UPON MOISTURE RETURN AND STORM MODE.

SQUALL-LINE DEVELOPMENT INSTEAD OF THE TENDENCY FOR DISCRETE

CONVECTION WOULD RESULT IN MORE OF A WIND DAMAGE THREAT.

FURTHER SOUTH ACROSS NE TX...FORECAST SOUNDINGS AT 21Z TO 00Z SHOW A

STOUT CAPPING INVERSION WHICH IS EXPECTED TO HOLD FOR MUCH OF THE

AFTERNOON AND EVENING. FOR THIS REASON...THE SEVERE THREAT SHOULD

DROP OFF QUICKLY WITH SWD EXTENT IN NE TX. DURING THE EVENING AND

OVERNIGHT PERIOD...THE MODELS ARE CONSISTENT WITH DEVELOPING AN MCS

IN THE OZARKS AND DRIVING THIS FEATURE EWD INTO THE LOWER TO MID MS

VALLEY. ALTHOUGH SEVERE THREAT COVERAGE SHOULD DECREASE DURING THE

LATE EVENING AND OVERNIGHT PERIOD...A THREAT FOR HAIL AND ISOLATED

WIND DAMAGE MAY CONTINUE AS FAR EAST AS SCNTRL MO AND ECNTRL AR

WHERE SFC DEWPOINTS SHOULD BE IN THE LOWER 60S F AND 40 TO 50 KTS OF

LOW-LEVEL FLOW IS FORECAST.

..BROYLES.. 04/13/2011

[SmokeEater]

30% hatched day 3 also.

DAY 3 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0228 AM CDT WED APR 13 2011

VALID 151200Z - 161200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER TO

MID-MS VALLEY...CNTRL GULF COAST...TN VALLEY AND OH VALLEY...

...LOWER TO MID-MS VALLEY/CNTRL GULF COAST/TN VALLEY/OH VALLEY...

A STRONG NEGATIVELY-TILED UPPER-LEVEL LOW IS FORECAST TO MOVE FROM

THE CNTRL PLAINS EWD INTO THE OZARKS ON FRIDAY. THE EXIT REGION OF A

WELL-DEVELOPED 80 TO 100 KT MID-LEVEL JET IS FORECAST TO SPREAD

ACROSS THE CNTRL GULF COAST STATES DURING THE DAY CREATING STRONG

DEEP LAYER SHEAR PROFILES FAVORABLE FOR SEVERE STORMS. THE

GFS...ECMWF AND NAM BEGIN THE DAY 3 PERIOD WITH AN MCS LOCATED IN

THE MID-MS VALLEY DRIVING THIS FEATURE EWD INTO WRN KY AND WRN TN BY

MIDDAY. SOUTH ACROSS THE WARM SECTOR...THE MODELS DEVELOP MODERATE

INSTABILITY ACROSS MUCH OF THE CNTRL GULF COAST STATES AND INITIATE

NUMEROUS THUNDERSTORMS FROM MIDDLE TN SWWD INTO NCNTRL AL...MS AND

SE LA DURING THE AFTERNOON. THE DEVELOPMENT OF A SEVERE MCS SEEMS

PROBABLE ACROSS THE CNTRL AND SRN PARTS OF THE SLIGHT RISK AREA

FRIDAY AFTERNOON AND EVENING.

FORECAST SOUNDINGS IN CNTRL MS AND WRN AL AT 21Z ON FRIDAY SHOW

IMPRESSIVE WIND SHEAR PROFILES WITH 50 TO 60 KT OF 0-6 KM SHEAR AND

0-3 KM STORM RELATIVE HELICITIES AROUND 400 M2/S2. THIS ENVIRONMENT

SHOULD SUPPORT SUPERCELL DEVELOPMENT WITH A THREAT FOR STRONG

TORNADOES POSSIBLE. HOWEVER...THE MAGNITUDE OF THE TORNADO THREAT

WILL BE CONDITIONAL UPON STORM MODE. IF A SQUALL-LINE WERE TO

DEVELOP INSTEAD OF MORE DISCRETE CONVECTION....THEN WIND DAMAGE

COULD BE THE GREATER THREAT. THE UPPER-LEVEL SYSTEM IS QUITE

IMPRESSIVE WITH A WELL-DEVELOPED LOW-LEVEL JET IN PLACE ACROSS THE

ECNTRL STATES. THE GFS AND NAM SOLUTIONS FOCUS THE LOW-LEVEL JET

FURTHER NORTH IN TN AND KY BY LATE AFTERNOON WHILE THE ECMWF SHOWS A

STRONG COMPONENT OF THE JET IN THE TN VALLEY AND CNTRL GULF COAST

STATES. IF THE ECMWF SOLUTION IS CORRECT AND MOISTURE RETURN ENDS UP

BEING STRONGER THAN FORECAST...THEN A TORNADO OUTBREAK COULD OCCUR

IN PARTS OF WRN TO MIDDLE TN...MS AND AL FRIDAY AFTERNOON. AT THIS

POINT...THE POTENTIAL FOR AN OUTBREAK REMAINS CONDITIONAL AND

DIFFERENCES IN THE MODEL SOLUTIONS RAISE UNCERTAINTIES CONCERNING

THE EXACT SCENARIO.

FURTHER NORTH ACROSS THE OH VALLEY...SEVERE STORMS WILL ALSO BE

POSSIBLE FRIDAY AFTERNOON AS THE UPPER-LEVEL LOW APPROACHES FROM THE

WEST. IN SPITE OF WEAKER INSTABILITY...A STRONG WIND FIELD IS

FORECAST WITH COLD TEMPS ALOFT. THIS WOULD RESULT IN A POTENTIAL FOR

HAIL AND WIND DAMAGE WITH THE MORE ORGANIZED CONVECTIVE CLUSTERS. A

TORNADO THREAT WILL ALSO BE POSSIBLE IN THE OH VALLEY DUE TO THE

STRONG LOW-LEVEL SHEAR FORECAST BUT THIS POTENTIAL SHOULD BE

DEPENDENT UPON MOISTURE RETURN.

..BROYLES.. 04/13/2011

[janetjanet998]

12z NAM looks likes its a little more moist and unstable then 00z

also a tad more south

[jmt]

The NAM seems to be trending toward a slightly narrower instability axis that also sets up farther west than earlier runs suggested. If you take the new run verbatim, I'm not sure that JLN ever destabilizes enough to have serious problems. On the other hand, I've noticed your area is notorious for overperforming events with apparently-questionable low-level moisture, particularly after dark. The hodographs are indeed rather crazy across the tri-state region.

Let's hope you are right and it doesn't destabilize enough.

[JoMo]

As janetjanet998 said, low is a bit farther south and faster with more moisture available according to the NAM. Currently, Mid 60 dewpoints in the Gulf where there were 40's yesterday, Houston area is in the mid 50's.The hodos out ahead of the storm are still pretty amazing, winds are even more backed it would seem now.

Springfield, MO had an excellent morning AFD that laid things out really well.

http://www.wundergro...CityName=Joplin

[Thundersnow12]

The 12z NAM has a tad more moisture into OK to the KS border but not going to believe that yet.

Also, the 9z SREF tor ingredients pops a 40 from 0-6z tomorrow evening from the OK/AR border to south-central AR.

Ouch, its popping a 50 from 18-0z on thursday around southeast MS/southwest AL.