April 14th, 2012 Plains High Risk

[CoastalWx]

Only this is that it solves the issue of convective initiation. Definitely increases the likelihood of the risk area verifying I think

Yeah if you have a 2-3 rounds of storms like some models have, certainly does increase the likely of the risk verifying.

[CoastalWx]

Those storms that the HRRR has developing late in the day might be the real bad boys.

[baroclinic_instability]

Just a reminder...might as well consider this "storm mode". Try and keep the silly banter to a minimum (or none at all). I have deleted a bunch of posts already.

[CT Rain]

17z balloon launch coming from OUN

[Buckeye05]

Didn't the March 2 outbreak start with morning convection?

[Superstorm93]

[SquatchinNY]

4/27/11 started with a morning MCS, but it was earlier than these storms.

[JetsPens87]

Those storms that the HRRR has developing late in the day might be the real bad boys.

Agreed, think that while certainly there is potential for this inititation this morning for dangerous situations, the LCL/LFC dif remains quite high, and the low level lapse rates are actually quite stable (likely a result from lingering low clouds). So while there certainly is potential for severe weather/isolated tornadoes this morning, I doubt if this is it.

[JoMo]

Extended higher tornado risk farther south.

[Zachary Lassiter]

For those thinking this will stop tonights show... NWS Norman doesn't think so

[ICEHOCEY77]

45% tornado risk expanded southward... details momentarily...

[JetsPens87]

For those thinking this will stop tonights show... NWS Norman doesn't think so

http://twitter.com/N...199760991010816

Anyone thinking this will directly inhibit the situation later tonight should revisit Alabama and a certain tornado outbreak last year.

[hm8]

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1120 AM CDT SAT APR 14 2012

VALID 141630Z - 151200Z

...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PORTIONS OF

NEBRASKA...KANSAS...AND OKLAHOMA...

..THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF NEBRASKA

WESTERN

IOWA...KANSAS...WESTERN MISSOURI...AND OKLAHOMA...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE

CENTRAL/SOUTHERN PLAINS...

...A SIGNIFICANT TORNADO OUTBREAK IS EXPECTED LATER TODAY AND

TONIGHT ACROSS PORTIONS OF NEBRASKA...KANSAS...AND OKLAHOMA...

A LARGE UPPER TROUGH REMAINS PLACED OVER THE WESTERN UNITED STATES

TODAY...WITH A STRONG MID/UPPER LEVEL JET EXTENDING FROM THE

SOUTHWEST STATES INTO THE CENTRAL PLAINS. WATER VAPOR IMAGERY AND

MORNING MODEL SOLUTIONS SUGGEST SEVERAL SUBTLE SHORTWAVE TROUGHS

EMBEDDED IN THE FASTER FLOW. THIS WILL RESULT IN THE POTENTIAL FOR

MULTIPLE ROUNDS OF SEVERE WEATHER OVER THE CENTRAL PLAINS TODAY.

THE FIRST CLUSTER OF SEVERE STORMS HAS NOW FORMED OVER SOUTHWEST KS

AND WILL LIKELY SPREAD NORTHEASTWARD INTO NEB THIS AFTERNOON AND

EVENING. THESE STORMS WILL BE IN AN INCREASINGLY VOLATILE AIR MASS

AS DAYTIME HEATING AND LOW LEVEL MOISTURE ADVECTION DESTABILIZE THE

REGION. LARGE HAIL AND DAMAGING WINDS ARE THE EARLY THREATS...BUT

AN INCREASING RISK OF SURFACE-BASED SUPERCELLS WILL POSE A THREAT OF

TORNADOES BY EARLY AFTERNOON. AS THE ACTIVITY MOVES INTO SOUTHERN

NEB...EVEN STRONGER LOW LEVEL SHEAR SUGGESTS THAT THE POTENTIAL FOR

STRONG TORNADOES WILL BE ENHANCED.

STRONG HEATING IS EXPECTED TO OCCUR ALONG THE DRYLINE LATER THIS

AFTERNOON AND EARLY EVENING OVER WESTERN KS INTO WESTERN OK. MODEL

SOLUTIONS SUGGEST THE CAP WILL BE WEAK BUT CONSIDERABLE UNCERTAINTY

REMAINS REGARDING THE EXTENT OF LARGE SCALE FORCING THIS EVENING.

AREAL COVERAGE OF STORMS COULD BE WIDELY SPACED. HOWEVER...

PARAMETERS TO THE EAST OF THE DRYLINE WILL BE EXTREMELY FAVORABLE

FOR TORNADIC SUPERCELLS CAPABLE OF LONG-TRACK... DAMAGING/VIOLENT

TORNADOES /4000 J/KG MLCAPE...50-60 KNOTS OF EFFECTIVE SHEAR...AND

0-3KM SRH VALUES OF 300-500 M2/S2/. THOSE STORMS THAT FORM MAY

PERSIST FOR SEVERAL HOURS AND TRACK ACROSS CENTRAL KS/OK AND INTO

SOUTHERN NEB.

FARTHER SOUTH...CONVECTIVE INITIATION BECOMES INCREASINGLY

UNCERTAIN. HOWEVER...WEAK CONVERGENCE ALONG THE DRYLINE COUPLED

WITH A WEAK CAP AND STEEP LOW LEVEL LAPSE RATES SUGGEST SOME THREAT

OF ISOLATED SEVERE STORMS ACROSS PARTS OF WESTERN NORTH TX.

..HART/COHEN.. 04/14/2012

[Superstorm93]

...A SIGNIFICANT TORNADO OUTBREAK IS EXPECTED LATER TODAY AND TONIGHT ACROSS PORTIONS OF NEBRASKA...KANSAS...AND OKLAHOMA... A LARGE UPPER TROUGH REMAINS PLACED OVER THE WESTERN UNITED STATES TODAY...WITH A STRONG MID/UPPER LEVEL JET EXTENDING FROM THE SOUTHWEST STATES INTO THE CENTRAL PLAINS. WATER VAPOR IMAGERY AND MORNING MODEL SOLUTIONS SUGGEST SEVERAL SUBTLE SHORTWAVE TROUGHS EMBEDDED IN THE FASTER FLOW. THIS WILL RESULT IN THE POTENTIAL FOR MULTIPLE ROUNDS OF SEVERE WEATHER OVER THE CENTRAL PLAINS TODAY.

[MNstorms]

http://www.ghcc.msfc.nasa.gov/GOES/GOES16102012105K1DCem.jpg

A loop of the clouds. http://charlie.wxcaster.com/loops/vis_loops.php?region=07

[baroclinic_instability]

The activity in KS is slightly elevated, but there is already surfaced based initiation across the Panhandles along the dryline. That is impressive that it is going up already. It should not have any problem initiating possibly multiple rounds of DMC today, and the afternoon and evening is when the ugly parameters come together. It doesn't seem like the I35 area was overhyped the way things are unfolding right now.

[SquatchinNY]

...

[jcwxguy]

here we go

[JetsPens87]

Of note: THe 90% RH between LCL/LFC is QUICKLY expanding through central KS ahead of the current batch of convection. As Low level lapse rates continue to steepen these storms could begin to rotate, especially the ones on the leading northern edge of the convection as they are about to hit some very unstable mid level airmass.

[Superstorm93]

Holy Cr@p

RUC STP:

Next Frame:

GREATER THAN 25

[Buckeye05]

...

Wow...that is ugly

[SquatchinNY]

Superstorm, can you get archived images of STP from the 4/27/11 and 3/2/12 outbreaks?

[JetsPens87]

The activity in KS is slightly elevated, but there is already surfaced based initiation across the Panhandles along the dryline. That is impressive that it is going up already. It should not have any problem initiating possibly multiple rounds of DMC today, and the afternoon and evening is when the ugly parameters come together. It doesn't seem like the I35 area was overhyped the way things are unfolding right now.

The way things are unfolding leave me with only a few factors I am questioning. The first was LCL/LFC height differences which is very very quickly looking to come together as the 90% RH field is fiercely expanding northward. So this drawback is being taken care of. Secondly, is the low level lapse rates, they are continuing to improve(destabalize) throughout the early morning, and with convection already thriving(albeit elevated) there is no reason to think that destabilization is but a mere few hours away. Last but not least for me is the larger scale forcing mechanisms, unlike the outbreak of last year, the larger forcing is not all in place. Wondering if the jetstreak is just a tad too far north/west to give the best forcing. Remember, all the ingredients can be there thermodynamically, but if the actual dynamics arent there then the threat is limited. Models do look more favorable with the jetstreak approaching western KS/southern NE by late afternoon which is likely why convection is being forecast to be later tonight. The combination of when the best forcing occurs and the best thermodynamic setup will be ey in just how severe this outbreak becomes. If the jetstreak approaches into a vastly unstable airmass then watch out, however if it waits even a little longer then suspected, the airmass could be turning more stable throughout the night(even though this would not completely diminish the threat, only prevent it from its full potential).

[Ginx snewx]

Remembering the last few seasons long track days morning visuals. Joplin, Tuscaloosa, Springfield Ma, all has similar vis sat sigs. The presentation at the AMWX conference about gravity waves prior to outbreaks was the first time I had heard about it  Looks volatile

[mclean02]

Remembering the last few seasons long track days morning visuals. Joplin, Tuscaloosa, Springfield Ma, all has similar vis sat sigs. The presentation at the AMWX conference about gravity waves prior to outbreaks was the first time I had heard about it Looks volatile

Thats what i was worried about seeing in this morning sat loop

[Superstorm93]

171

ACUS11 KWNS 141645

SWOMCD

SPC MCD 141644

KSZ000-OKZ000-TXZ000-141745-

MESOSCALE DISCUSSION 0523

NWS STORM PREDICTION CENTER NORMAN OK

1144 AM CDT SAT APR 14 2012

AREAS AFFECTED...CNTRL/WRN KS...NWRN OK...OK/TX PANHANDLES

CONCERNING...TORNADO WATCH 165...

VALID 141644Z - 141745Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 165 CONTINUES.

SEVERE WEATHER THREAT ACROSS PARTICULARLY DANGEROUS SITUATION

TORNADO WATCH 165 WILL BE EVOLVING WITHIN TWO SPATIAL REGIMES

THROUGH 1730Z:

1. ONGOING ELEVATED THUNDERSTORMS...INCLUDING SUPERCELLS...NORTH A

OF A DODGE CITY TO GARDEN CITY KANSAS LINE...WILL SHIFT NEWD. WITH

THE DOWNSTREAM AIR MASS REMAINING RELATIVELY COOL OWING TO THE

STRATUS DECK...MODIFIED 12Z DDC RAOB SUGGESTS THAT THESE STORMS WILL

REMAIN SOMEWHAT ELEVATED DURING THE NEXT HOUR OR SO AND POSE MAINLY

A THREAT FOR SEVERAL HAIL...SOME POSSIBLY VERY LARGE.

HOWEVER...STRONG LOW-LEVEL SHEAR MAY SUPPORT THE THREAT FOR ONE OR

TWO TORNADOES WITH THIS INITIAL ROUND OF STORMS AS THE INHIBITION

ERODES WITH AT LEAST SOME DIURNAL HEATING.

2. INCREASING CONVECTION DEVELOPING IN SWRN KS SWD INTO THE ERN TX

PANHANDLE WILL MOVE NEWD BEHIND THE INITIAL ROUND OF STORMS. VERY

LITTLE CINH FOR A SFC-BASED PARCEL INTO THE TX/OK PANHANDLES PER 12Z

AMA RAOB SUGGESTS THAT SURFACE-BASED SUPERCELLS MAY QUICKLY EVOLVE

FROM THIS ACTIVITY DURING THE NEXT HOUR OR TWO...WITH THE THREAT FOR

TORNADOES INCREASING INTO THE AFTERNOON.

..COHEN.. 04/14/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...TOP...ICT...OUN...GID...DDC...GLD...AMA...

LAT...LON 39999937 39989800 39779685 38299742 36389768 36099987

36370099 37500110 38620104 39710045 39999937

[Disc]

Storm NE of Jetmore, KS has some mid-level rotation showing up on the high tilts.

[JetsPens87]

Storm NE of Jetmore, KS has some mid-level rotation showing up on the high tilts.

Yup, nothing is really holding back these storms except for the low level lapse rates right now. All other factors are moderately/very favorable.

[baroclinic_instability]

The way things are unfolding leave me with only a few factors I am questioning. The first was LCL/LFC height differences which is very very quickly looking to come together as the 90% RH field is fiercely expanding northward. So this drawback is being taken care of. Secondly, is the low level lapse rates, they are continuing to improve(destabalize) throughout the early morning, and with convection already thriving(albeit elevated) there is no reason to think that destabilization is but a mere few hours away. Last but not least for me is the larger scale forcing mechanisms, unlike the outbreak of last year, the larger forcing is not all in place. Wondering if the jetstreak is just a tad too far north/west to give the best forcing. Remember, all the ingredients can be there thermodynamically, but if the actual dynamics arent there then the threat is limited. Models do look more favorable with the jetstreak approaching western KS/southern NE by late afternoon which is likely why convection is being forecast to be later tonight. The combination of when the best forcing occurs and the best thermodynamic setup will be ey in just how severe this outbreak becomes. If the jetstreak approaches into a vastly unstable airmass then watch out, however if it waits even a little longer then suspected, the airmass could be turning more stable throughout the night(even though this would not completely diminish the threat, only prevent it from its full potential).

Yeah you make valid points regarding upper level synoptic/subsynoptic forcing...not nearly as impressive as April 27th or March 2nd 2012, for instance. Much of the forcing is actually leeside cyclogenesis until the trough ejects after dark, but watch the action of the dual jet config. That will provide more than sufficient exhaust/divergence across much of the WCB of this cyclone across the plains.

[FSMweather]

Btw we have a day two moderate with a 45% percent hatch.