Discussion (May 18-19-20-21) Moore Tornado EF-5 from NWS

[CrazyC83]

That is one dramatic picture! Luckily it lifted before town it appears

[Cyclenall]

Wow,look at this photo of tornado in SW Rozel Kansas. You have another option to post videos and photos and that is in the Sticky 2013 U.S Severe Weather Season (Videos-Photos-Stats-Forecast thread

HOLY CRAP!!!!!!! That has to be the best looking tornado of 2013 so far! That looks like the Seymour TX tornado of April 10 1979!! (which was one of the most ominous plains tornadoes of the 1970s "looking"):

Seymour TX tornado of April 10 1979:

[cycloneye]

I moved the post you made at the watches and warnings thread to this one.

[Bunkertor]

^ roping out

[cycloneye]

Cyclenall,that is why I posted that photo at the sticky thread to continue to document the 2013 season with those extraordinary photos.

[cycloneye]

Reports so far on May 18 of Tornadoes,Wind and Hail.

[Cyclenall]

I've been extremely underwhelmed with the hail sizes so far, not even cracking 3"...pretty laughable...even a normal day can do better.

[CrazyC83]

Yet that tornado will likely go down as an EF-0 since I haven't heard of any damage.

[WeatherGuesser]

I only count 17 TOR Warnings so far and many of those were for the same storms as they moved into new areas.

[CrazyC83]

How will today's under-performance (or at least under-reporting) play into tomorrow? A morning MCS could either make things more prime by adding shear lines or kill the instability completely...

Worthy of a High Risk?

[Ntxw]

How will today's under-performance (or at least under-reporting) play into tomorrow? A morning MCS could either make things more prime by adding shear lines or kill the instability completely...

Worthy of a High Risk?

I would not put a high risk. High risk should be reserved for the classic jet streak outbreaks. We are not working with a strong upper wind pattern to make use of the parameters. A localized event certainly! However I would take each day differently as timing, the way these shortwaves eject and not be too worked up on instability or what occurred the day before. I have to say it again, this is not the look of the classic outbreaks where storms fire off a triple point and long track tornadoes travel along a warm front. It is highly dependent on the dry-line and if storms move into the best conditions at the right time.

[WeatherGuesser]

Moderate for Monday now. That makes 3 consecutive Moderate days.

SPC AC 190600

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT SUN MAY 19 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM PARTS OF SERN KS/W CENTRAL
AND SWRN MO SWWD INTO CENTRAL OK...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY/UPPER
GREAT LAKES REGION SSWWD INTO N CENTRAL TX...

...SYNOPSIS...
A LARGE UPPER LOW IS FORECAST TO LINGER IN PLACE ACROSS THE SD/NEB
VICINITY...WHILE A MID-LEVEL JET STREAK AROUND THE SRN FRINGE OF THE
LOW EJECTS FROM THE SRN ROCKIES INTO THE CENTRAL U.S. DURING THE
PERIOD. WHILE A SECOND LOW/TROUGH IS FORECAST TO APPROACH THE PAC
NW COAST LATE...THE CENTRAL U.S. STORM SYSTEM WILL BE THE SYSTEM OF
INTEREST WITH RESPECT TO SEVERE POTENTIAL ON MONDAY.

AT THE SURFACE...A LOW IS FORECAST TO REMAIN OVER THE SD VICINITY
BENEATH THE UPPER LOW...WITH A TRAILING COLD FRONT FORECAST TO SHIFT
EWD ACROSS THE PLAINS. AS THE AFOREMENTIONED JET STREAK SHIFTS INTO
THE S CENTRAL PORTION OF THE COUNTRY...SECONDARY CYCLOGENESIS IS
FORECAST TO OCCUR ALONG THE FRONT IN THE SWRN OK VICINITY...NEAR THE
INTERSECTION OF THE FRONT AND A DEVELOPING DRYLINE. THE COLD FRONT
AND DRYLINE SHOULD SERVE AS PRIMARY FOCI FOR AFTERNOON DEVELOPMENT
OF WIDESPREAD/SEVERE STORMS.

...UPPER MS VALLEY/UPPER GREAT LAKES SWWD INTO THE SRN PLAINS...
WHILE DETAILS REMAIN DIFFICULT TO DISCERN DUE TO MULTIPLE ROUNDS OF
WIDESPREAD/INTERVENING CONVECTION...ANOTHER SUBSTANTIAL SEVERE
WEATHER EVENT IS FORECAST MONDAY/DAY 2 ACROSS THE CENTRAL CONUS.

WEAKENING/DIMINISHING CONVECTION MAY BE ONGOING AHEAD OF THE FRONT
ACROSS THE WARM SECTOR...BUT AS STORMS/CLOUDINESS WANE THROUGH THE
MORNING IN MOST AREAS...EXPECT THE ONSET OF HEATING TO DRIVE STRONG
AIRMASS DESTABILIZATION. BY LATE AFTERNOON...THE
PRE-FRONTAL/PRE-DRYLINE WARM SECTOR SHOULD FEATURE 2500 TO 3500 J/KG
MIXED-LAYER CAPE. AS LARGE-SCALE ASCENT -- AIDED BY THE APPROACHING
JET STREAK AND FOCUSED ALONG LOW-LEVEL BOUNDARIES --
INCREASES...EXPECT DEVELOPMENT/RAPID GROWTH OF INITIAL CONVECTION
DURING THE MID AFTERNOON HOURS. AS SHEAR INCREASES IN CONJUNCTION
WITH INTENSIFYING FLOW ALOFT...STORMS SHOULD RAPIDLY ACQUIRE
ROTATION -- PARTICULARLY WHERE CAPE/SHEAR JUXTAPOSITION APPEARS MOST
FAVORABLE ACROSS THE MDT RISK AREA. HERE...THREAT FOR VERY LARGE
HAIL AND TORNADOES WILL EXIST. THREAT FOR DAMAGING WINDS WILL
INCREASE INTO THE EVENING...AS STORMS EVOLVE INTO LINEAR CLUSTERS IN
SOME AREAS. EVEN SO...ROTATING/SUPERCELL STORMS SHOULD LINGER
LOCALLY WELL INTO THE EVENING HOURS -- WITH CONTINUED TORNADO AND
LARGE HAIL POTENTIAL. THREAT SHOULD FINALLY BEGIN TO DIMINISH
OVERNIGHT...AS THE AIRMASS SLOWLY COOLS/STABILIZES -- PARTICULARLY
ACROSS NRN PORTIONS OF THE RISK AREA.

..GOSS.. 05/19/2013

Day 3 (TUE) Slight Risk area is literally from Canada to Mexico

[wx247]

How will today's under-performance (or at least under-reporting) play into tomorrow? A morning MCS could either make things more prime by adding shear lines or kill the instability completely...

Worthy of a High Risk?

I would not put a high risk. High risk should be reserved for the classic jet streak outbreaks. We are not working with a strong upper wind pattern to make use of the parameters. A localized event certainly! However I would take each day differently as timing, the way these shortwaves eject and not be too worked up on instability or what occurred the day before. I have to say it again, this is not the look of the classic outbreaks where storms fire off a triple point and long track tornadoes travel along a warm front. It is highly dependent on the dry-line and if storms move into the best conditions at the right time.

Agreed. High risk days from the SPC are reserved for those classic setups. This isn't really one of those. There still remain some model discrepancies, too, which worries forecasters. That being said... today looks to be a dangerous day and with the numerous outdoor activities going on across the area, I hope everyone is paying attention to the weather, too. We shall see how things progress throughout the day.

[RL3AO]

Its a mid-level moderate day.

[wx247]

Its a mid-level moderate day.

RL... I was kind of in the same camp with you when I first got up, but looking at the latest data this morning I am a bit more concerned. Latest indications are this may be a bit more than that... although not quite a high risk. Seems the NAM is out to lunch based upon the surface features this morning. Accordingly, SPC has upped the ante just a bit with their latest tornado progs in the last hour.

Maybe I am just a bit more on edge because Joplin High School's graduation is today and being from the area and remembering all too well the nightmare of 5/22/11... I will anxiously be following the situation as it unfolds today.

[RL3AO]

Joplin forecast soundings

RAP (23z)



NAM (0z)



GFS (0z)



RAP/NAM are pretty good looking but nothing that screams high risk.



However, this is around Tulsa at 3z. Appears to be much more of a higher end moderate risk sounding. Super high instability and some due south winds at the lower level instead of SSW. One of the negatives could be lower dewpoints near the surface creating higher lcl's.

[SouthDadeFish]

RL,

Here is the 12Z RAP EHI forecast for 03Z tonight:



It shows a bullseye around Tulsa. That forecast sounding shows some strong helicity in the lower levels, and the RAP echoes this with helicity values exceeding 550 right around Tulsa. Interesting set up...

[CrazyC83]

The EHI's were nothing spectacular yesterday (which I knew would limit tornado coverage), but that is enormous there for today! That may have a High Risk case at 1630 but they will likely wait for it to start.

[cycloneye]

Boundaries are present and those may serve as trigger for tronadic activity later this afternoon and evening.

[TropicalAnalystwx13]

The latest runs of the RAP are disconcerting to say the least. An upgrade to high risk is definitely possible, though they may hold off to 20z if they do so.

Joplin has a high school graduation today and their weather radios are down.