Upgrade to High Risk today possible.

http://www.spc.noaa.gov/products/outlook/day1probotlk_1630_torn.gif

Don't really know where to post this question...but I have been wondering. Only one time do I remember a tornado hitting a downtown area of a major city, and that was Ft. Worth several years ago. Is there a reason why large downtowns don't usually get hit, or is it just luck? And...what would happen to downtown OKC if a mile wide EF4/EF5 like the one that hit Moore would take a direct path down Sheridan?

Has Aaron Tuttle gone off the deep end with his thoughts?
https://www.facebook.com/ATsFans

So the right time to sensationalize the weather is at the moment it's actually happening, absolutely not before?

Don't really know where to post this question...but I have been wondering. Only one time do I remember a tornado hitting a downtown area of a major city, and that was Ft. Worth several years ago. Is there a reason why large downtowns don't usually get hit, or is it just luck? And...what would happen to downtown OKC if a mile wide EF4/EF5 like the one that hit Moore would take a direct path down Sheridan?

So probably a bunch of small towns in Oklahoma have never got hit by a tornado, either. Why is that? There would be no doubt a lot of skyscraper windows blasted out if a strong tornado came to downtown OKC.

Don't really know where to post this question...but I have been wondering. Only one time do I remember a tornado hitting a downtown area of a major city, and that was Ft. Worth several years ago. Is there a reason why large downtowns don't usually get hit, or is it just luck? And...what would happen to downtown OKC if a mile wide EF4/EF5 like the one that hit Moore would take a direct path down Sheridan?

I think its been a matter of luck, personally.

Upgrade to High Risk today possible.

Can we expect a PDS tornado watch?

Don't really know where to post this question...but I have been wondering. Only one time do I remember a tornado hitting a downtown area of a major city, and that was Ft. Worth several years ago. Is there a reason why large downtowns don't usually get hit, or is it just luck? And...what would happen to downtown OKC if a mile wide EF4/EF5 like the one that hit Moore would take a direct path down Sheridan?

Just luck of the draw in my opinion. If something strong hit downtown we would definitely see a ton of glass damage and such. I think the structures would mostly survive, but i'm not a structural engineer. :)

Can we expect a PDS tornado watch?

I would imagine they'll be PDS watches today, yes.

http://www.srh.noaa.gov/images/fxc/oun/graphicast/image1.jpg

Don't really know where to post this question...but I have been wondering. Only one time do I remember a tornado hitting a downtown area of a major city, and that was Ft. Worth several years ago. Is there a reason why large downtowns don't usually get hit, or is it just luck? And...what would happen to downtown OKC if a mile wide EF4/EF5 like the one that hit Moore would take a direct path down Sheridan?


Just luck of the draw in my opinion. If something strong hit downtown we would definitely see a ton of glass damage and such. I think the structures would mostly survive, but i'm not a structural engineer.

So there's no "truth" to the idea that the urban downtown center creates its own micro-climate from the air-handling units and building height that would weaken a storm front? Seems I heard that somewhere, but perhaps it's more urban myth than reality.

Visible satellite imagery is beautiful right now. Really paints the boundaries out. You can see fluffy cumulous in all of the danger zone.

Temperatures in NC OK are already at 85F. You could swim in the air today, A/Cs will be working overtime.

I would not be surprised to see a PDS TOR watch for the first time this year.


The last High Risk issued was over a year ago during a multi-day event in April 2012 over OK and KS.

Storm Prediction Center May 31, 2013 1630 UTC Day 1 Convective Outlook (http://www.spc.noaa.gov/products/outlook/day1otlk.html)
...REGIONAL SEVERE WEATHER OUTBREAK POSSIBLE TODAY OVER PARTS OF
CENTRAL/EASTERN OK...SOUTHEAST KS...AND SOUTHWEST MO. VERY LARGE
HAIL...WIDESPREAD DAMAGING WINDS...AND A FEW STRONG/VIOLENT
TORNADOES ARE POSSIBLE...

...OK/KS/MO...
ANOTHER VERY VOLATILE ENVIRONMENT IS IN PLACE ACROSS PARTS OF THE
SOUTHERN PLAINS AND MID MS VALLEY TODAY. WIDESPREAD VERY STEEP MID
LEVEL LAPSE RATES AND DEWPOINTS IN THE UPPER 60S/LOWER 70S ARE
RESULTING IN THE POTENTIAL FOR AFTERNOON MLCAPE VALUES OVER 4000
J/KG. THIS AIR MASS IS CURRENTLY CAPPED...AND THE CAP SHOULD
RESTRAIN DEEP CONVECTION THROUGH MUCH OF THE DAY ALLOWING STRONG
HEATING.
BY MID/LATE AFTERNOON...A SHORTWAVE TROUGH INDICATED IN WATER VAPOR
IMAGERY OVER THE TX PANHANDLE...ALONG WITH A SECOND AND STRONGER
TROUGH OVER CO...WILL APPROACH THE REGION. THIS WILL RAPIDLY WEAKEN
THE CAP AND ALLOW EXPLOSIVE THUNDERSTORM DEVELOPMENT ALONG THE
DRYLINE OVER WEST-CENTRAL OK...AND ALONG THE COLD FRONT EXTENDING
FROM CENTRAL OK INTO SOUTHWEST MO. DEEP LAYER EFFECTIVE SHEAR
VALUES ARE FAVORABLE FOR SUPERCELL STORMS CAPABLE OF VERY LARGE
HAIL...DAMAGING WINDS...AND TORNADOES. SHEAR VECTORS PERPENDICULAR
TO THE N-S DRYLINE OVER CENTRAL OK WILL FAVOR DISCRETE STORM
STRUCTURES. ALL 12Z MODEL GUIDANCE INDICATES RAPID INTENSIFICATION
OF THE LOW LEVEL JET OVER CENTRAL OK BY EVENING AS THE UPPER TROUGH
APPROACHES. GIVEN THESE PARAMETERS...IT APPEARS THE THREAT OF A FEW
STRONG/VIOLENT TORNADOES ARE IN PLACE.

This is what we can see right now. The red lines are outflow boundaries left by yesterday's convection. Storms can behave differently (good or bad) if they get along these boundaries. Illustrated below by my really sought after drawing skills.

http://img822.imageshack.us/img822/3106/may312013.png

Don't really know where to post this question...but I have been wondering. Only one time do I remember a tornado hitting a downtown area of a major city, and that was Ft. Worth several years ago. Is there a reason why large downtowns don't usually get hit, or is it just luck? And...what would happen to downtown OKC if a mile wide EF4/EF5 like the one that hit Moore would take a direct path down Sheridan?There have been quite a few more. One tore through the middle of downtown Wichita Falls back in the 50s, and another did the same at Waco years later. Those are two I remember right off without searching the records.

In the summer of 1959 one ran right through downtown OKC, from SW 59 and Portland to a golf course northeast of Lincoln Park. All that saved us was that it was around an EF0 strength and was above ground most of the way. However I took photos of building damage at SW 3 and Robinson (the brick cornices blown off of the roof but no damage at ground level) that were in the paper the next day, and the golf course was nearly demolished -- with a major PGA tournament scheduled for the next few days.

There was another one in the 70s that took out part of Windsor Lanes (NW 23 and Meridian) then went east in the middle of NW 23 until veering northeast and blowing Shotgun Sam away from his pizza parlor at NW 39 and May. This one I rode out in my neighbor's basement, around 3 a.m., after KTOK misreported its location as NW 23 and May...

It's just a matter of luck.

This is what we can see right now. The red lines are outflow boundaries left by yesterday's convection. Storms can behave differently (good or bad) if they get along these boundaries. Illustrated below by my really sought after drawing skills.

http://img822.imageshack.us/img822/3106/may312013.png

My MS Paint skills are better. :-p hehe

Seriously though, great depiction of where everything is right now. Very complex setup with the additional boundaries. This moisture pouring in is just incredible as well...

http://www.mesonet.org/data/public/mesonet/maps/realtime/current.TDEW.grad.png

There have been quite a few more. One tore through the middle of downtown Wichita Falls back in the 50s, and another did the same at Waco years later. Those are two I remember right off without searching the records.

In the summer of 1959 one ran right through downtown OKC, from SW 59 and Portland to a golf course northeast of Lincoln Park. All that saved us was that it was around an EF0 strength and was above ground most of the way. However I took photos of building damage at SW 3 and Robinson (the brick cornices blown off of the roof but no damage at ground level) that were in the paper the next day, and the golf course was nearly demolished -- with a major PGA tournament scheduled for the next few days.

There was another one in the 70s that took out part of Windsor Lanes (NW 23 and Meridian) then went east in the middle of NW 23 until veering northeast and blowing Shotgun Sam away from his pizza parlor at NW 39 and May. This one I rode out in my neighbor's basement, around 3 a.m., after KTOK misreported its location as NW 23 and May...

It's just a matter of luck.

To add to your fine post
The metro areas of Tulsa, Wichita, KC, Lubbock, Dallas, Miami, Los Angeles Saint Louis, Salt lake city, Atlanta, Washington DC, near Boston and even New York City has had tornadoes and that just off the top of my head.

http://img822.imageshack.us/img822/3106/may312013.png

Surely everyone who has viewed this pic notices the outflow boundary right over the Moore area. Hope storms don't act bad down there.

In Stillwater:

Temperature: 86F
Heat Index: 95F
Feels like: 106F
Dew Point: 75F

Should be getting the report from the 18Z sounding in Norman soon.

To add to your fine post
The metro areas of Tulsa, Wichita, KC, Lubbock, Dallas, Miami, Los Angeles Saint Louis, Salt lake city, Atlanta, Washington DC, near Boston and even New York City has had tornadoes and that just off the top of my head.

One went through downtown Atlanta in 2008. It was around an EF3 if I recall correctly.

A lot of information coming out from NWS Norman today...so just some things to keep in mind...

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
131 PM CDT FRI MAY 31 2013




...DANGEROUS STORMS POSSIBLE THIS AFTERNOON AND EVENING...


YOUR BEST OPTIONS FOR TORNADO SAFETY ARE (IN THIS ORDER)


1. IN AN UNDERGROUND STORM SHELTER, STORM CELLAR, BASEMENT OR
ENGINEERED SAFE ROOM DESIGNED TO WITHSTAND A TORNADO.


2. ON THE LOWEST FLOOR OF A STURDY BUILDING,
A. STAY AWAY FROM DOORS, WINDOWS AND OUTSIDE WALLS.
B. PUT AS MANY WALLS BETWEEN YOU AND THE TORNADO AS YOU CAN.
C. USE AS MANY PILLOWS, COUCH CUSHIONS, SLEEPING BAGS, A MATTRESS
OR BLANKETS TO COVER UP AS YOU CAN.
D. IF YOU OR YOUR CHILDREN HAVE HELMETS, WEAR THEM!
E. IF YOU HAVE AN INFANT, PUT THEM IN THEIR CAR SEAT OR CARRIER


OTHER IMPORTANT SHELTERING REMINDERS:


* WEAR LONG PANTS, LONG SLEEVE SHIRT, AND REAL SHOES
(NOT FLIP FLOPS OR SANDALS!)
* CHARGE YOUR CELL PHONE AND TAKE IT WITH YOU TO SHELTER
* MAKE SURE YOU KNOW WHAT YOU WILL DO WITH YOUR PETS. FIND
LEASHES AND CARRIERS NOW.


YOU CAN SURVIVE ALMOST EVERY TORNADO IF YOU FOLLOW THESE GUIDELINES!


IF YOU DO NOT FEEL SAFE FROM A TORNADO WHERE YOU ARE, AND YOU
FEEL THE NEED TO DRIVE SOMEWHERE ELSE TO FIND BETTER SHELTER, IT
IS CRITICAL THAT YOU DO NOT WAIT TOO LATE TO MAKE THAT CRITICAL
DECISION.


IF YOU WAIT UNTIL THE TORNADO WARNING IS IN EFFECT FOR YOUR
LOCATION, IT IS PROBABLY TOO LATE TO BE ABLE TO DRIVE AWAY SAFELY!!


IF YOU CHOOSE TO LEAVE IN YOUR VEHICLE, BE SURE YOU KNOW WHERE YOU
ARE GOING BEFORE YOU START THE CAR. TRY TO LET SOMEONE KNOW YOU
ARE NOT AT HOME AND WHERE YOU ARE GOING.


DO NOT ASSUME THAT PUBLIC BUILDINGS ARE TORNADO SHELTERS. CHECK
WITH YOUR LOCAL COMMUNITY WHILE THE SUN IS STILL SHINING AND
BEFORE STORMS EVER DEVELOP!


BE SURE THAT YOU ARE NOT PUTTING YOURSELF IN MORE DANGER BY DRIVING
INTO ANOTHER STORM.

OK. So there are more than I remembered. My bad. But my real question query is..."what would an EF4/5 do to the Devon Tower or Chase Tower or First National. Would they come down? Would then stay standing? I know glass would be all over...but are they built to withstand 200+ mph winds?

http://www.mesonet.org/data/public/mesonet/maps/realtime/current.wx.gif?1370025430145

SE shift to the winds starting to work in to the Norman area and South.

So, has the timeline moved at all? I just heard on News9 they're saying the timeline is from 2p-2a. . . Is that just a prediction of when the storms might hit or will they continually fire off?

So, has the timeline moved at all? I just heard on News9 they're saying the timeline is from 2p-2a. . . Is that just a prediction of when the storms might hit or will they continually fire off?

HRRR is holding to the 3-4PM time frame to fire things off...waiting to see the OUN sounding and how stout the cap still is. That'll give us a better idea.

there is supposed to be storms next week .Will they be severe or what?

there is supposed to be storms next week .Will they be severe or what?

I think most manpower and resources are focued on today. I'm sure tomorrow they will start to look ahead into more detail.

http://www.spc.noaa.gov/products/md/mcd0905.gif

MESOSCALE DISCUSSION 0905
NWS STORM PREDICTION CENTER NORMAN OK
0149 PM CDT FRI MAY 31 2013


AREAS AFFECTED...NERN OK...SERN KS...CNTRL/SWRN MO


CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY


VALID 311849Z - 312045Z


PROBABILITY OF WATCH ISSUANCE...95 PERCENT


SUMMARY...TSTM COVERAGE SHOULD INCREASE RAPIDLY IN THE NEXT FEW
HOURS. HIGHLY FAVORABLE COMBINATION OF CAPE/SHEAR WILL YIELD
SUPERCELLS WITH RISKS OF LARGE HAIL /SOME SIGNIFICANT/...TORNADOES
/POSSIBLY STRONG/ AND ISOLATED DAMAGING WINDS.


DISCUSSION...TCU/SMALL CBS HAVE BECOME INCREASINGLY AGITATED ALONG A
COUPLE OF SW/NE-ORIENTED CLOUD STREETS ACROSS FAR SERN KS.
LARGE-SCALE ASCENT ASSOCIATED WITH PERSISTENT LOW-LEVEL WAA AND
APPROACH OF A SHORT WAVE IMPULSE OVER THE CNTRL HIGH PLAINS SHOULD
FOSTER DEEPENING CONVECTION THROUGH THE AFTERNOON. MODIFIED 18Z SGF
RAOB SUGGESTS MLCIN HAS BECOME MINIMAL WITH PRESENCE OF A STRONGLY
UNSTABLE AIR MASS. ALTHOUGH LOW-LEVEL SHEAR MAY DIMINISH SLIGHTLY
OVER THE NEXT FEW HOURS...IT WILL REMAIN MORE THAN ADEQUATE FOR
SUPERCELLS AND AN ASSOCIATED TORNADO RISK. THIS THREAT MAY BE
MAXIMIZED INVOF REMNANT OUTFLOW BOUNDARY ARCING ACROSS PARTS OF
CNTRL MO.


..GRAMS/HART.. 05/31/201

Has the supercell birth area shifted?

http://climate.cod.edu/data/raob/KOUN/skewt/KOUN.skewt.20130531.18.gif

Anyone on the SE side of OKC confirm the 75F mesonet reading? Seems very odd considering areas around it are almost 90F.

Anyone on the SE side of OKC confirm the 75F mesonet reading? Seems very odd considering areas around it are almost 90F.

Nothing on the WUnderground network backing that up at all.

Strange. Maybe that mesonet is in a unique physical location. Temperature has since gone on the rise, up to 79F.

Edit: And now it is offline. Looks like misreading/errors. Perhaps they are resetting it.

Sooooooooooooooo...the supercell birthing area has moved north and east?

Sooooooooooooooo...the supercell birthing area has moved north and east?

What? No.

If you are referring to the MD that venture posted, that is the area highlighted for the discussion that they are posting about. We will have our own MD soon, I assume.

PDS Tornado Incoming

http://www.spc.noaa.gov/products/md/mcd0907.gif

MESOSCALE DISCUSSION 0907
NWS STORM PREDICTION CENTER NORMAN OK
0240 PM CDT FRI MAY 31 2013


AREAS AFFECTED...MOST OF OK


CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY


VALID 311940Z - 312115Z


PROBABILITY OF WATCH ISSUANCE...95 PERCENT


SUMMARY...PDS TORNADO WATCH WILL BE ISSUED BY 21Z. ISOLATED TO SCATTERED DISCRETE SUPERCELLS SHOULD FORM ALONG DRYLINE BETWEEN 21-23Z WITH PRIMARY INITIAL THREAT OF VERY LARGE HAIL AND ISOLATED SEVERE WINDS. TORNADO RISK WILL INCREASE TOWARDS 00Z WITH AN EXPECTATION OF A FEW SIGNIFICANT TORNADOES.


DISCUSSION...19Z SURFACE ANALYSIS PLACED A QUASI-STATIONARY FRONT FROM GRANT TO CUSTER COUNTIES WITH A DRYLINE DRAPED S/SWWD INTO THE LOW ROLLING PLAINS OF NWRN TX. SURFACE TEMPERATURES HAVE NOW BREACHED 100 DEG F ALONG THE RED RIVER IN SWRN OK/NWRN TX...RESULTING IN MINIMAL MLCIN PER MODIFIED 18Z OUN RAOB. CU JUST AHEAD OF THE DRYLINE HAS BECOME MORE AGITATED IN LATEST VISIBLE SATELLITE IMAGERY AND SHOULD CONTINUE TO GROW WITH GLANCING INFLUENCE OF A SHORTWAVE IMPULSE OVER THE CNTRL HIGH PLAINS. THIS SHOULD RESULT IN TSTM INITIATION BY 21Z.


STRONG EFFECTIVE SHEAR WILL PROMOTE SUPERCELLS WITH AN INITIAL PRIMARY RISK OF VERY LARGE HAIL. WITH A PLUME OF 73-74 DEG F SURFACE DEW POINTS REMAINING ACROSS CNTRL OK BENEATH THE CAPPING INVERSION NOTED IN 18Z OUN RAOB...AND AS THE LLJ INTENSIFIES BY 00Z...TORNADO THREAT WILL INCREASE SUBSTANTIALLY. SOME OF THESE WILL LIKELY BE SIGNIFICANT...ESPECIALLY ALONG THE I-35 CORRIDOR.


..GRAMS/HART.. 05/31/2013

Please help us with the jargon. What does 21-23z mean?

Take any times like that and subtract 5. That is local time in military time. So 4-6PM.

I believe that's time? 4-6pm?

Second PDS of 2013 unless I am missing one.

We are staying with a MDT risk for now...

...OK...SERN KS INTO SWRN MO...
STORMS ARE BEGINNING TO FORM OVER SERN KS ALONG THE COLD FRONT...AS
WELL AS ALONG THE OUTFLOW BOUNDARY INTO W CNTRL MO. 18Z SGF SOUNDING
SHOWED A LOADED GUN PROFILE WITH STEEP MIDLEVEL LAPSE RATES AND A
VERY DEEP MOIST BOUNDARY LAYER AND A SUPERCELL TORNADO HODOGRAPH.
WITH LIFTED INDICIES OF -10 TO -12...A COUPLE STRONG TORNADOES WILL
BE POSSIBLE IN ADDITION TO VERY LARGE HAIL.


FARTHER S INTO OK...THE 18Z OUN SOUNDING SHOWED A PRONOUNCED CAPPING
INVERSION...WITH A VERY MOIST AND DEEPENING BOUNDARY LAYER WITH
PRECIPITABLE WATER AROUND 1.50 INCHES. OK MESONET OBSERVATIONS
CONTINUE TO SHOW DEWPOINTS HOLDING IN THE LOWER 70S F WITH EXTREME
INSTABILITY IN PLACE.


HIGHER BASED CU HAVE RECENTLY FORMED OVER NW TX AND SWRN OK WHERE
TEMPERATURES WERE NEARING 100 F...AND THE GREATEST PRESSURE FALLS
ARE CENTERED IN THIS REGION AS WELL. MODELS ALSO CONTINUE TO SHOW
CYCLOGENESIS THROUGH THE EVENING...WITH WINDS OVER CNTRL OK BECOMING
MORE BACKED WITH TIME. THIS WILL HAVE THE EFFECT OF ENLARGING
HODOGRAPHS AND SRH VALUES. THIS WILL ALSO LIKELY PULL THE STATIONARY
BOUNDARY...NOW FROM N CNTRL INTO WRN OK...SWD TO NEAR I-40. CELLS
THAT FORM OVER SWRN OR W CNTRL OK WILL MOVE E WITH A VERY HIGH
THREAT OF GIANT HAIL AND A FEW STRONG TO VIOLENT TORNADOES. ONE
CAVEAT IS INITIAL LCL HEIGHTS IN THE HOTTER AIR...AND POTENTIAL
OUTFLOW MAGNITUDE. HOWEVER...THE EXTREMELY FAVORABLE SUPERCELL
ENVIRONMENT IS EXPECTED TO KEEP STORMS MAINLY CELLULAR...HELPING TO
COUNTERACT ANY NEGATIVE OUTFLOW EFFECTS.


LATER IN THE EVENING...A SEVERE MCS AND/OR ADDITIONAL SUPERCELLS ARE
STILL LIKELY ACROSS MUCH OF NRN AND NERN OK INTO SWRN MO...WITH
DAMAGING WINDS AND A FEW TORNADOES.

Second PDS of 2013 unless I am missing one.

I believe that's correct. First was up in OH/IN/IL that busted.

http://www.spc.noaa.gov/products/watch/ww0262_radar.gif

Tornadoes
Probability of 2 or more tornadoes

High (90%)
Probability of 1 or more strong (F2-F5) tornadoes

High (70%)
Wind
Probability of 10 or more severe wind events

High (90%)
Probability of 1 or more wind events > 65 knots

Mod (50%)
Hail
Probability of 10 or more severe hail events

High (>95%)
Probability of 1 or more hailstones > 2 inches

High (90%)
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events

High (>95%)
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 262
NWS STORM PREDICTION CENTER NORMAN OK
330 PM CDT FRI MAY 31 2013


THE NWS STORM PREDICTION CENTER HAS ISSUED A


* TORNADO WATCH FOR PORTIONS OF
CENTRAL AND NORTHEAST OKLAHOMA


* EFFECTIVE THIS FRIDAY AFTERNOON FROM 330 PM UNTIL MIDNIGHT CDT.


...THIS IS A PARTICULARLY DANGEROUS SITUATION...


* PRIMARY THREATS INCLUDE...
SEVERAL INTENSE TORNADOES LIKELY
NUMEROUS VERY LARGE HAIL EVENTS TO 4 INCHES IN DIAMETER LIKELY
NUMEROUS DAMAGING WIND GUSTS LIKELY WITH SEVERAL SIGNIFICANT
GUSTS TO 80 MPH POSSIBLE


THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES WEST NORTHWEST OF
BARTLESVILLE OKLAHOMA TO 30 MILES EAST OF WICHITA FALLS TEXAS.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU2).


PRECAUTIONARY/PREPAREDNESS ACTIONS...


REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.


&&


OTHER WATCH INFORMATION...CONTINUE...WW 260...WW 261...


DISCUSSION...AN EXTREMELY UNSTABLE AIR MASS HAS DEVELOPED ACROSS
MUCH OF CENTRAL/EASTERN OK THIS AFTERNOON. THIS WILL LIKELY RESULT
IN RAPID DEVELOPMENT OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING ALONG THE DRYLINE OVER WEST-CENTRAL OK...AND ALONG A WEAK
BOUNDARY EXTENDING NORTHEASTWARD INTO NORTHEAST OK. DISCRETE
SUPERCELLS CAPABLE OF EXTREMELY LARGE HAIL AND DAMAGING TORNADOES
ARE POSSIBLE. DAMAGING WINDS WILL BECOME AN INCREASING THREAT
THROUGH THE EVENING.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
600. MEAN STORM MOTION VECTOR 26025.

Mm

Four inch hail? That's wider than my palm. Good lord.

Four inch hail? That's wider than my palm. Good lord.

Indeed. Sometimes the hail can cause more damage than the tornadoes.

Please help us with the jargon. What does 21-23z mean?Just to give a bit of background to help your understanding. More than 60 years ago the powers that be assigned letters to the 24 possible time zines around the world, omitting I and O from the alphabet to avoid confusing them with numerals. The zone just to the east of the UK was given the letter "A" and the rest of the alphabet followed, with "Z" winding up as Greenwich Mean Time or GMT (now known as UTC to remove any locale bias). The letters do not recognize Daylight Saving or Summer times; they remain on the standard clock all year round.

Originally this was a military standard to avoid confusion when an army or navy was on the move. By specifying times with a letter suffix to indicate the zone, commanders could be assured that all clocks were in sync with each other.

It's now become the standard for all international communications, such as weather reports.

Cell in Kay County to the ESE of Newkirk is going to be severe soon, so be ready up there.

First PDS TWatch of the year. Yikes! Stay safe everyone!

http://www.weatherspotlight.com/screencap/may13/ktlx_20130531_2124.png

http://www.weatherspotlight.com/screencap/may13/31-2.png

http://www.weatherspotlight.com/screencap/may13/ktlx_20130531_2136.png

As things are going fast, I'll try to past as much as I can. Please stay tuned to the Chat room as well: Live Chat | Weather Spotlight (http://www.weatherspotlight.com/?page_id=40)

All NWS tweets/warnings/etc are auto posted in there as soon as they are issued.

http://www.weatherspotlight.com/screencap/may13/31-3.png

Hinton storm is worrisome to OKC.

Chat is going.

http://www.spc.noaa.gov/products/md/mcd0908.gifMESOSCALE DISCUSSION 0908
NWS STORM PREDICTION CENTER NORMAN OK
0458 PM CDT FRI MAY 31 2013


AREAS AFFECTED...WCNTRL THROUGH CNTRL AND NERN OK


CONCERNING...TORNADO WATCH 262...


VALID 312158Z - 312330Z


THE SEVERE WEATHER THREAT FOR TORNADO WATCH 262 CONTINUES.


SUMMARY...STORMS WILL UNDERGO A RAPID INCREASE IN ORGANIZATION AND
INTENSITY OVER WCNTRL AND SWRN OK. THE STORMS ARE EXPECTED TO MATURE
INTO SUPERCELLS AND BECOME CAPABLE OF PRODUCING VERY LARGE HAIL AND
STRONG TORNADOES AS THEY MOVE EWD AND ENEWD TOWARD CNTRL OK THIS
EVENING.


DISCUSSION...EARLY THIS EVENING A COLD FRONT EXTENDS FROM ERN KS
SWWD THROUGH NWRN OK THEN WWD INTO THE NRN TX PANHANDLE. A DRYLINE
EXTENDS FROM WRN TX NWD INTO WRN OK WHERE IT INTERSECTS THE DRYLINE.
TRENDS IN SATELLITE IMAGERY SHOW CUMULUS CONGESTUS INCREASING WITHIN
THE MORE DEEPLY MIXED REGIME NEAR THE DRYLINE ACROSS SWRN OK AND THE
FIRST STORMS ARE INITIATING ALONG THE DRYLINE/FRONT INTERSECTION
NEAR WATONGA. THE ATMOSPHERE DOWNSTREAM IS VERY UNSTABLE WITH 4000+
J/KG MLCAPE WITH DEWPOINTS IN THE LOW 70S AND VERY STEEP LAPSE RATES
ALONG WITH EFFECTIVE SHEAR IS AROUND 50 KT. LOW LEVEL HODOGRAPHS ARE
NOT PARTICULARLY LARGE...BUT WINDS NEAR THE SFC ARE BACKED TO SSELY
ACROSS CNTRL-WCNTRL OK...AND HODOGRAPHS WILL GRADUALLY INCREASE IN
SIZE AS THE LLJ STRENGTHENS. THIS ENVIRONMENT WILL SUPPORT EXPLOSIVE
THUNDERSTORM DEVELOPMENT WITH STORMS RAPIDLY ORGANIZING INTO
SUPERCELLS CAPABLE OF PRODUCING VERY LARGE HAIL AND STRONG TORNADOES
AS THEY MOVE ENEWD THROUGH THE VERY MOIST AND UNSTABLE WARM SECTOR
NEXT FEW HOURS.


..DIAL.. 05/31/2013

The Hinton storm is worrisome, since I think the two to the north of it will merge which will disrupt rotating supercells. The south end of this will track straight through N OKC and Memorial Rd. Quail Springs should close.

The Hinton storm is worrisome, since I think the two to the north of it will merge which will disrupt rotating supercells. The south end of this will track straight through N OKC and Memorial Rd. Quail Springs should close.

Penn Square Mall, virtually all of NWOKC and S. Edmond in the strike zone. Seems like it will go tornadic once it reaches El Reno or Yukon, then head into West OKC.