Days 4 to 7 - Discussion

[pottyprof]

meso discussion issued..

MCD - 01/2230Z

ACUS11 KWNS 012102

SWOMCD

SPC MCD 012102

OKZ000-KSZ000-012230-

MESOSCALE DISCUSSION 0757

NWS STORM PREDICTION CENTER NORMAN OK

0402 PM CDT THU MAY 01 2008

AREAS AFFECTED...CNTRL OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 012102Z - 012230Z

TSTM INITIATION REMAINS UNCERTAIN THROUGH THE NEXT COUPLE OF HOURS

ALONG DRYLINE WHICH HAS MIXED TO NEAR THE I-35 CORRIDOR. SUPERCELLS

WOULD LIKELY OCCUR...PREDICATED ON TSTM DEVELOPMENT. THE AREA WILL

BE MONITORED FOR A POSSIBLE WW.

20Z OUN RAOB HAS SHOWN A SUBSTANTIAL WEAKENING OF THE CAPPING

INVERSION DEPICTED ON THE EARLIER 12Z RAOB. VIS SATELLITE IMAGERY

OVER THE PAST HOUR OR SO HAS SHOWN ATTEMPTS AT CU DEVELOPMENT ALONG

DRY LINE...PRIMARILY OVER S-CNTRL OK IN GRADY/STEPHENS COUNTIES.

MAJORITY OF LATEST MODEL GUIDANCE SUGGEST TSTM DEVELOPMENT IS

UNLIKELY THROUGH 00Z...AS CONVERGENCE ALONG THE DRYLINE AND

LARGE-SCALE ASCENT APPEARS MODEST. STILL...12Z HI-RES WRF-NMM

DEPICTS ISOLATED DEVELOPMENT INVOF CURRENT CU AREA AROUND 21Z. IF

THIS WERE TO INDEED OCCUR...MODERATE TO STRONG INSTABILITY WITH

MLCAPES OF 2000 TO 3000 J/KG AND EFFECTIVE SHEAR AROUND 40 KTS WOULD

BE SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS AS

THE PRIMARY THREATS. A MORE PROBABLE SCENARIO IS FOR TSTM

DEVELOPMENT AFTER 00Z INVOF N-CNTRL OK AS DEEPER ASCENT SPREADS EWD

FROM SERN CO/SWRN KS AND LOW-LEVEL FLOW BACKS/STRENGTHENS IN

RESPONSE TO APPROACHING WAVE.

..GRAMS.. 05/01/2008

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

ATTN...WFO...TSA...ICT...OUN...

36289652 35209684 34439725 34289780 34459808 35249777

[Gorky]

I'm still in Independance. Internet connectivity is a real problem, as I had issues with my computer. I have remedied it and now just suffering from crawling speeds. Since I was last on, it looks like a small swarm of spotters are in my local area. That's some sort of good news I guess! I've checked out the terrain around here also, and it's fairly good north towards Freedonia, but terrible South and West of here.

[dallas]

Some info from Accuweather

Tornadoes Possible in Kan., Mo. and Okla.

Thursday, May 01, 2008

A STORM IN KANSAS WILL PRODUCE SEVERE STORMS, INCLUDING THE POTENTIAL FOR TORNADOES, THIS AFTERNOON ACROSS KANSAS INTO OKLAHOMA AND PARTS OF WESTERN MISSOURI...

I was wondering why SPC did not have a moderate risk of severe weather out this morning across Kansas, then I just checked again at the time of this writing and saw that they have added a moderate risk across Kansas. From my point of view, this is almost a textbook case of supercell thunderstorm development in the Plains with potential for large tornadoes produced by the supercells. The storms will probably wait until after 6pm CDT to develop since the jet is lagging behind across the Rockies. Once they do develop, we will see explosive thunderstorm development with storms becoming severe within 30 minutes of the initial development.

Overnight, storms will develop along the entire cold front from Iowa down to north Texas, and there may be a threat of tornadoes from western Missouri to northern Texas overnight. In any case, wind damage and hail will be associated with the storms overnight into Friday as the line continues to march eastward.

Edited May 1, 2008 by dallas

[Roger J Smith]

In general the dew points are a little on the low side for this to be a sure-fire classic severe weather event, but I like the development in western KS where dew points are only 4-6 C, it could take another two hours for anything much to get going north to northwest of Wichita, then it should fire around 01z heading pretty close to where both team and Gorky are located. As the night progresses this could get more severe in western MO than at any point in eastern KS, so, not sure what anyone would want to do about sampling that, but my guess is that if tornadoes are not visible somewhere in eastern KS before sunset, they will probably just be developing at that point and may do some significant damage in western Missouri around midnight.

The best sign to watch for would be any discrete cells around Pratt KS to Enid OK phasing with the advancing w/c KS activity. This might be expected around 2230z from the current J-field analysis.

[MAF]

from NOAA/SPC Day two forecast

THOUGH STRONGEST FLOW ALOFT WILL SPREAD ACROSS NRN PORTIONS OF THE

OUTLOOK AREA...SHEAR MORE THAN SUFFICIENT FOR SUPERCELLS WILL LIKELY

EXTEND ACROSS A LARGE PORTION OF THE WARM SECTOR -- FROM E TX/NRN

LA/WRN MS NWD. ATTM...IT APPEARS THAT THE MOST FAVORABLE

SHEAR/INSTABILITY COMBINATION WILL EXIST BETWEEN 02/21Z AND 03/03Z

FROM ROUGHLY CENTRAL IL/SERN MO SWD ACROSS ERN AR/NWRN MS. ALONG

WITH POTENTIALLY A MORE LINEAR ZONE OF STORMS -- WITH EMBEDDED

ROTATION -- INVOF THE SURFACE FRONT...MORE ISOLATED STORMS ARE ALSO

EXPECTED TO DEVELOP WITHIN THE WARM SECTOR INVOF MORE SUBTLE

BOUNDARIES. GIVEN THE DEGREE OF LOW-LEVEL SHEAR AND DEWPOINTS WELL

INTO THE 60S ACROSS A LARGE AREA...TORNADOES -- A FEW POTENTIALLY

STRONG/LONG-LIVED -- ARE ANTICIPATED. DEGREE OF INSTABILITY ALSO

SUPPORTS LARGE HAIL AND LOCALLY-DAMAGING WINDS WITH

LONG-LIVED/WELL-ORGANIZED STORMS -- BOTH LINEAR AND CELLULAR.

CONVECTION SHOULD CONTINUE SHIFTING EWD ACROSS THE MS VALLEY THROUGH

THE EVENING/OVERNIGHT...AND THOUGH A SLOW DECREASE IN SEVERE THREAT

IS ANTICIPATED WITH THE LOSS OF DAYTIME HEATING...SOME THREAT WILL

LIKELY PERSIST THROUGH 03/12Z.

[Mammatus]

Keep the posts coming guys, enjoying this virtual chase. Only 19 days till I fly out to DFW to meet Paul.S and the team

Have purchased www.supercellchaser.com and .co.uk all ready for my return from the US where I can 'hopefully snap away and capture some awesome images of the thunderstorms ready to upload on my new website which I'm developing.

Sounds like your having a superb time out there Gorky, keep us upto date with your movements-

Gavin (Mammatus)

Edited May 1, 2008 by Mammatus

[Rob]

sounds great out there i love americas weather, i wish we had their climate

[pottyprof]

Second meso discussion issued..

MCD - 01/2330Z

ACUS11 KWNS 012157

SWOMCD

SPC MCD 012156

MOZ000-KSZ000-OKZ000-012330-

MESOSCALE DISCUSSION 0758

NWS STORM PREDICTION CENTER NORMAN OK

0456 PM CDT THU MAY 01 2008

AREAS AFFECTED...ERN KS...NWRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 012156Z - 012330Z

ALTHOUGH ISOLATED TSTM DEVELOPMENT IS POSSIBLE THROUGH 00Z...MORE

PROBABLE INITIATION APPEARS LIKELY BETWEEN 00-03Z AS STRONGER

LARGE-SCALE ASCENT AND COLD FRONT OVERTAKE THE DRYLINE.

STRENGTHENING LOW/MID-LEVEL SHEAR WILL PROVE FAVORABLE FOR

SUPERCELLS INITIALLY LIKELY GROWING UPSCALE INTO A QUASI-LINEAR

CONVECTIVE SYSTEM LATER THIS EVENING. LARGE HAIL /SOME POSSIBLY

SIGNIFICANT/...DAMAGING WINDS...AND ISOLATED TORNADOES SHOULD OCCUR.

A WW WILL LIKELY BE REQUIRED.

RECENT VIS SATELLITE IMAGERY INDICATE DEEPENING CU FIELD ALONG THE

DRYLINE FROM AROUND 20 E PNC TO STJ. 21Z TOP RAOB DEPICTED NEARLY

COMPLETE REMOVAL OF CAPPING INVERSION...EVEN WITH SURFACE DEW POINTS

IN THE LOWER 50S SAMPLING JUST W OF DRY LINE. MODIFYING FOR LOWER

60S DEW POINTS WITHIN THE MOIST SECTOR YIELDS A MODERATE TO STRONGLY

UNSTABLE AIR MASS WITH MLCAPES OF 2000 TO 3000 J/KG. STILL WITH ONLY

MODEST ASCENT ALONG THE DRY LINE ATTM...THERE IS UNCERTAINTY AS TO

THE EXTENT OF CONVECTIVE GROWTH PRIOR TO 00Z.

TSTM DEVELOPMENT APPEARS MORE PROBABLE AFTER 00Z AS STRONGER FORCED

ASCENT SPREADS EWD /AS INDICATED BY HIGH-BASED CONVECTION OVER SWRN

KS/...AND AS SURFACE COLD FRONT EVENTUALLY INTERSECTS THE DRY LINE.

LATEST MODEL GUIDANCE REMAIN CONSISTENT WITH A RETREAT OF THE DRY

LINE FARTHER W FROM NEAR ICT TO TOP BY 03Z AS LOW-LEVEL FLOW BACKS

AND STRENGTHENS WITH RESPONSE TO APPROACHING WAVE. ABUNDANT

DIRECTIONAL/SPEED SHEAR WILL PROVE FAVORABLE FOR UPDRAFT ROTATION

AND LIKELY SUPERCELLS WITH INITIAL DEVELOPMENT...AND ATTENDANT

THREATS FOR LARGE HAIL/DAMAGING WINDS/ISOLATED TORNADOES.

..GRAMS.. 05/01/2008

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

ATTN...WFO...EAX...TSA...TOP...ICT...OUN...

36629670 36699729 37049788 37619784 38139712 39039604

Right on target

[Gorky]

Looks like initiation jsut west of me. Path of these cells would be in the Freedonia area so I'm going to move 10 miles or so North and see what they look like

[pottyprof]

Stay safe Nath mate and enjoy!!

This is the first precipitation from these cells

[dallas]

From NOAA

--------------------------------------------------------------------------------

Tornado Watch

--------------------------------------------------------------------------------

TORNADO WATCH OUTLINE UPDATE FOR WT 243

NWS STORM PREDICTION CENTER NORMAN OK

435 PM CDT THU MAY 1 2008

TORNADO WATCH 243 IS IN EFFECT UNTIL 1100 PM CDT FOR THE

FOLLOWING LOCATIONS

SDC003-005-009-011-015-017-023-025-027-035-043-049-057-059-061-

067-069-073-077-079-083-087-097-099-101-111-115-125-127-135-

020400-

/O.NEW.KWNS.TO.A.0243.080501T2135Z-080502T0400Z/

SD

. SOUTH DAKOTA COUNTIES INCLUDED ARE

AURORA BEADLE BON HOMME

BROOKINGS BRULE BUFFALO

CHARLES MIX CLARK CLAY

DAVISON DOUGLAS FAULK

HAMLIN HAND HANSON

HUTCHINSON HYDE JERAULD

KINGSBURY LAKE LINCOLN

MCCOOK MINER MINNEHAHA

MOODY SANBORN SPINK

TURNER UNION YANKTON

[MAF]

radar picking up now http://www.spc.noaa.gov/products/watch/ww0243.html

Tornado area above

[Roger J Smith]

Good call Gorky, you may need to go further north, cells likely to move NNE and also back build in response to developing upstream wave.

Team if still in Emporia may be okay to await but would be wise to drift southeast. Yates Centre to Burlington about the target zone, but could still see tornadic action further north.

[MAF]

a more detailed map. showing current watch ( #243) area

[SHOUY]

Good luck all you guys, Im sitting here in the Uk with all the radars on the web running and loving this forum. I see some storms really popping up fast and moving n,east. Fredonia and Buffalo look a good bet. Plus there is a new supercell moving in behind it. We all want some video posted soon.. All stay safe... Shouy.

[Cookie]

welcome shouy!

thanks for the updates guys I love a virtual chase!

[MAF]

welcome to NW shouy. glad you can join in in the chase

Probability of 2 or more tornadoes Mod (40%)

Probability of 1 or more strong (F2-F5) tornadoes Low (20%)

courtesy NOAA/SPC

Edited May 1, 2008 by Mick

[pottyprof]

What a super line of cells.. Couldn't have been a better call for the NW team and Nath.. WTG Guys!!

[MAF]

some pretty hefty stuff there Paul. they certainly are in a nice line

[Cookie]

What a super line of cells.. Couldn't have been a better call for the NW team and Nath.. WTG Guys!!

do you get that from the normal bog standed Google earth?

[Roger J Smith]

It's good to see this line, however, they are relatively small and svr wx characteristics at current radar depiction would be modest, I have seen reports of spatterings of 1 inch hail. Feel that more potent cells may develop in a while perhaps out of this line but possibly from a second line not formed yet. No doubt will make for good photography being isolated.

They could go tornadic at any moment though. Would get to a point midway Yates Centre and Chanute for the biggest cell approaching.

[pottyprof]

do you get that from the normal bog standed Google earth?

Ill get you a link mate..

New tornado watch just popped up for Oklahoma.... Those cloud tops look very high up around the Kansas/Missouri border..

[MAF]

areas covered by watch #243

http://www.spc.noaa.gov/products/watch/ws0243.html

courtesy NOAA/SPC

Watch #245 isuued now

starting to get busy me thinks

http://www.spc.noaa.gov/products/watch/ww0245.html

[NL]

Two inch hail from the cell in Franklin county Kansas, line of storms

starting to intensify. Just been following chasers with streaming cams

skyline looking quite ominous.

Edited May 1, 2008 by NL

[SHOUY]

can believe its getting so good over there and i have to get up for work in a few hours doh!!

If anybody is interested im using The Weather Channel local interactive maps very good.

http://www.weather.com/weather/map/interac...om=hp_main_maps

All the best Shouy.