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May 15-20 Severe Weather Obs/Discussion (Part 2)

SmokeEater

By SmokeEater,
in Central/Western States

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thunderman

thunderman

Posted
Posted

We watched the Rozel storm for a while. It was clearly a strong tornado and the first time it touched down it was down for at least 15-20 minutes.  The 3rd touchdown also lasted about 10-15 mins.  It was an impressive tornado and LCLs were fine.

 

Oh wow, I was not aware that it was on the ground for that long.  I saw the warning/TDS and then it was roping out on the feeds not long after that.

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JoMo

JoMo

Posted
Posted

Good luck to the chasers today. Stay safe everyone. Once again, keep the disco clean and meteorological, and limit the questions and/or comments that don't contribute to the event once activity ramps up. I will be watching closely from the forecast desk in cold Alaska :)

 

I will gladly trade you places today. Cold sounds great right about now. 

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Chinook

Chinook

Posted
Posted

I think this will be a pretty big day, with a better potential for tornadoes in more areas than yesterday. Maybe more than the 22 tornadoes of yesterday. The STP (significant tornado parameter) will be pretty high. See the image below. It's a 6 hour forecast. The LCL's will be 1250m for some of the moderate risk area, which is medium, if you want a tornado threat (I think.)

 

post-1182-0-65191600-1368984353_thumb.pn

 

post-1182-0-61176900-1368984354_thumb.pn

 

 

 

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jojo762

jojo762

Posted
Posted

Widespread SB-CAPE surging north into Kansas, and is already prevalent across  most of Oklahoma. With instability already pooling along the dryline in OK with CAPE values of 3000+j/kg occurring. Doesn't appear that moisture should be much of an issue anymore, not thinking that LCL's should be an issue either with 2000m+ LCL's currently staying behind the dryline for now, and a large area of 1000m over the Moderate Risk. Not expecting terribly large temperature-dewpoint spreads, with dewpoints being in the upper 60's to low 70's, and temps should be in the upper 70's to mid 80's...

Although none of the wind fields at least ATTM appear too impressive though, with 0-6km srh of AOA 40kts. And the best helicities being around 150m2/s2, and the best (250m2s2) currently over Southwest Missouri...

 

Thoughts...?

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Wx 24/7

Wx 24/7

Posted
Posted

I don't want to fill up this page with lengthy copy/paste jobs, but I felt this snippet from an updated TSA AFD is noteworthy:

ALL SIGNS CONTINUE TO POINT TOWARD SIGNIFICANT SEVERE WEATHER LATETHIS AFTERNOON AND EVENING PRIMARILY ACROSS NE OK. STORMS MAY BEJUST AS INTENSE FURTHER SOUTH AND EAST ACROSS EAST CENTRAL OK INTONW AR HOWEVER THEY ARE LIKELY TO BE REDUCED IN NUMBER WITHEASTWARD AND SOUTHWARD EXTENT. LESS DEEP MOISTURE AND A STRONGCAPPING INVERSION CONTINUE TO SUPPORT MUCH LOWER STORM CHANCESTOWARD SE OK.  FORECAST WIND PROFILES SUPPORT A WINDOW OF FAVORABLE SHEARPARAMETERS FOR STRONG TO VIOLENT TORNADOES. WHETHER THIS ISREALIZED WILL DEPEND LARGELY ON EVENTUAL STORM/S/EVOLUTION...HOWEVER UNDERSTANDING THE POTENTIAL EXISTS ISNOTEWORTHY.
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baroclinic_instability

baroclinic_instability

Posted
Posted

 

I don't want to fill up this page with lengthy copy/paste jobs, but I felt this snippet from an updated TSA AFD is noteworthy:

ALL SIGNS CONTINUE TO POINT TOWARD SIGNIFICANT SEVERE WEATHER LATETHIS AFTERNOON AND EVENING PRIMARILY ACROSS NE OK. STORMS MAY BEJUST AS INTENSE FURTHER SOUTH AND EAST ACROSS EAST CENTRAL OK INTONW AR HOWEVER THEY ARE LIKELY TO BE REDUCED IN NUMBER WITHEASTWARD AND SOUTHWARD EXTENT. LESS DEEP MOISTURE AND A STRONGCAPPING INVERSION CONTINUE TO SUPPORT MUCH LOWER STORM CHANCESTOWARD SE OK.  FORECAST WIND PROFILES SUPPORT A WINDOW OF FAVORABLE SHEARPARAMETERS FOR STRONG TO VIOLENT TORNADOES. WHETHER THIS ISREALIZED WILL DEPEND LARGELY ON EVENTUAL STORM/S/EVOLUTION...HOWEVER UNDERSTANDING THE POTENTIAL EXISTS ISNOTEWORTHY.

I think that AFD sums it up nicely. A classic way of noting potential but alluding to uncertainties. Forecasters are good at it. 

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JoMo

JoMo

Posted
Posted

 

I don't want to fill up this page with lengthy copy/paste jobs, but I felt this snippet from an updated TSA AFD is noteworthy:

 

Check out Springfield's. I think the summary is paragraph 6. Lots of detail. 

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Chinook

Chinook

Posted
Posted

I think that AFD sums it up nicely. A classic way of noting potential but alluding to uncertainties. Forecasters are good at it. 

What I've noticed in some of the nastiest tornado outbreaks over the years is this: The 250mb and 300mb jet level winds are even higher than the 500mb, in the area of the tornadic storms. Like for example, 500mb is at 40 knots, then 300mb would be at 50 knots, maybe 250mb would be at 55 knots or higher. I believe some of the research says that higher jet-level storm relative winds will be a predictor of the supercell type, i.e. from HP to classic to LP.  (in that order.)

 

I think what I've seen is the classic type supercells with medium to high winds at 300mb (with an increased speed compared to 500mb) will be ones that have at least a 25% chance of producing a tornado.

 

Today, SE Kansas should have a 500mb wind of 55kt and a 300mb wind of 75kt. (based of 16z RAP) This is certainly a warning sign for higher tornado severity.

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Superstorm93

Superstorm93

Posted
Posted

 

MESOSCALE DISCUSSION 0697
NWS STORM PREDICTION CENTER NORMAN OK
1251 PM CDT SUN MAY 19 2013

AREAS AFFECTED...NRN OK...SCNTRL THROUGH ERN KS...EXTREME SERN NEB
AND WRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191751Z - 191945Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP BY 20Z...MOST LIKELY OVER
SCNTRL KS INTO NCNTRL OK. STORMS WILL SUBSEQUENTLY CONTINUE THROUGH
THE WARM SECTOR OVER ERN KS...NERN OK AND EVENTUALLY WRN MO THIS
EVENING. INITIAL THREATS WILL BE SUPERCELLS WITH VERY LARGE HAIL AND
TORNADOES...A FEW OF WHICH COULD BE STRONG.

DISCUSSION...EARLY THIS AFTERNOON A DRYLINE EXTENDS FROM WRN TX INTO
FAR WRN OK THEN NWWD INTO THE OK PANHANDLE WHERE IT INTERSECTS A
COLD FRONT. A WEAKENING OUTFLOW BOUNDARY EXISTS NEAR THE OK/KS
BORDER AND HAS BEEN LIFTING SLOWLY NWD. SATELLITE IMAGERY ALSO
INDICATES AN EWD PROPAGATING GRAVITY WAVE FROM SCNTRL KS INTO NWRN
OK. UPPER 60S DEWPOINTS ARE ADVECTING NWD THROUGH THE WARM SECTOR
BENEATH VERY STEEP /8-9 C/KM/ MID LEVEL LAPSE RATES. THESE FACTORS
ALONG WITH DIABATIC WARMING WILL CONTRIBUTE TO STRONG INSTABILITY
WITH 3000-4000 J/KG MLCAPE BY MID AFTERNOON. WARM AIR AT THE BASE OF
THE EML IS SERVING TO CAP THE BOUNDARY LAYER TO SFC BASED STORMS IN
THE NEAR TERM. HOWEVER...MESOSCALE FORCING FOR ASCENT ASSOCIATED
WITH EWD PROPAGATING GRAVITY WAVE LOCATED WITHIN UPPER JET EXIT
REGION AS WELL AS DRYLINE CONVERGENCE SHOULD CONTRIBUTE TO
THUNDERSTORM INITIATION AS CONVECTIVE TEMPERATURES ARE REACHED
TOWARD MID-LATE AFTERNOON.

MID-UPPER JET ROTATING THROUGH BASE OF THE TROUGH IS RESULTING IN
50+ KT DEEP SHEAR SUPPORTIVE OF SUPERCELLS. 0-2 KM HODOGRAPHS WILL
ALSO BE SUFFICIENT FOR LOW LEVEL MESOCYCLONES...AND THREAT FOR A FEW
STRONG TORNADOES WILL EXIST GIVEN THE STEEP LAPSE RATES AND
MAGNITUDE OF INSTABILITY.

..DIAL/KERR.. 05/19/2013


 

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CT Rain

CT Rain

Posted
Posted

 

attachicon.gifmcd0697.gif

 

MESOSCALE DISCUSSION 0697

NWS STORM PREDICTION CENTER NORMAN OK

1251 PM CDT SUN MAY 19 2013

AREAS AFFECTED...NRN OK...SCNTRL THROUGH ERN KS...EXTREME SERN NEB

AND WRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191751Z - 191945Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP BY 20Z...MOST LIKELY OVER

SCNTRL KS INTO NCNTRL OK. STORMS WILL SUBSEQUENTLY CONTINUE THROUGH

THE WARM SECTOR OVER ERN KS...NERN OK AND EVENTUALLY WRN MO THIS

EVENING. INITIAL THREATS WILL BE SUPERCELLS WITH VERY LARGE HAIL AND

TORNADOES...A FEW OF WHICH COULD BE STRONG.

DISCUSSION...EARLY THIS AFTERNOON A DRYLINE EXTENDS FROM WRN TX INTO

FAR WRN OK THEN NWWD INTO THE OK PANHANDLE WHERE IT INTERSECTS A

COLD FRONT. A WEAKENING OUTFLOW BOUNDARY EXISTS NEAR THE OK/KS

BORDER AND HAS BEEN LIFTING SLOWLY NWD. SATELLITE IMAGERY ALSO

INDICATES AN EWD PROPAGATING GRAVITY WAVE FROM SCNTRL KS INTO NWRN

OK. UPPER 60S DEWPOINTS ARE ADVECTING NWD THROUGH THE WARM SECTOR

BENEATH VERY STEEP /8-9 C/KM/ MID LEVEL LAPSE RATES. THESE FACTORS

ALONG WITH DIABATIC WARMING WILL CONTRIBUTE TO STRONG INSTABILITY

WITH 3000-4000 J/KG MLCAPE BY MID AFTERNOON. WARM AIR AT THE BASE OF

THE EML IS SERVING TO CAP THE BOUNDARY LAYER TO SFC BASED STORMS IN

THE NEAR TERM. HOWEVER...MESOSCALE FORCING FOR ASCENT ASSOCIATED

WITH EWD PROPAGATING GRAVITY WAVE LOCATED WITHIN UPPER JET EXIT

REGION AS WELL AS DRYLINE CONVERGENCE SHOULD CONTRIBUTE TO

THUNDERSTORM INITIATION AS CONVECTIVE TEMPERATURES ARE REACHED

TOWARD MID-LATE AFTERNOON.

MID-UPPER JET ROTATING THROUGH BASE OF THE TROUGH IS RESULTING IN

50+ KT DEEP SHEAR SUPPORTIVE OF SUPERCELLS. 0-2 KM HODOGRAPHS WILL

ALSO BE SUFFICIENT FOR LOW LEVEL MESOCYCLONES...AND THREAT FOR A FEW

STRONG TORNADOES WILL EXIST GIVEN THE STEEP LAPSE RATES AND

MAGNITUDE OF INSTABILITY.

..DIAL/KERR.. 05/19/2013

 

 

Great minds think alike lol 

 

Winds are a bit more backed than the NAM showed around Tulsa and into adjacent SE Kansas. Will be interesting to watch that over the next 2-3 hours once CI is underway. 

post-40-0-83711900-1368986613_thumb.gif

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Superstorm93

Superstorm93

Posted
Posted

That gravity wave looks absolutely nasty on visible 

 

Should be extremely interesting to see how the cells look once they initiate off of that thing. I'm not all up in arms about a "major outbreak" today or anything, but I definitely think that we could see one or two very well documented, strong tornadoes. 

 

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Superstorm93

Superstorm93

Posted
Posted

GOES-WEST will be in SRSO for today's severe weather

 

The data will be found here: http://rammb.cira.colostate.edu/dev/lindsey/loops/

 

NOUS72 KNES 191548
ADMNES
SUBJECT: ADMINISTRATIVE: GOES-15 (GOES-WEST) SRSO SCHEDULED FOR MAY
*TOPIC: *GOES-15 (GOES-WEST) SRSO IS SCHEDULED FOR MAY 19, 2013

*DATE/TIME**ISSUED: *MAY 19, 2013 1535 UTC*****
*

*PRODUCT(S) OR DATA IMPACTED:*GOES-15 (GOES-WEST) IMAGER DATA AND
PRODUCTS**

*DATE/TIME OF INITIAL IMPACT:*MAY 19, 2013****J-DAY 139 @ 1959 UTC*
*

*DATE/TIME OF EXPECTED END:*MAY 20, 2013 J-DAY 140 @ 0559 UTC****

*LENGTH OF OUTAGE:*10 HOURS *
*

*DETAILS/SPECIFICS OF CHANGE:*SRSO REQUESTED BY CIRA FOR SUPPORT OF THE
IFLOODS FIELD EXPERIMENT. THE CENTER POINT IS 40N 101W.

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