Oklahoma Severe Weather Discussion - April 2012

[venture]

Tornado watch is up now for the northwest quarter of oklahoma until 9pm.

Now to figure out how to copy/paste on my android. Lol

[venture]

Severe thunderstorm watch is now in effect for the southwest quarter of the state.

[Tydude]

.a severe thunderstorm warning remains in effect until 430 pm
cdt for northeastern harper and northwestern woods counties...

At 400 pm cdt...national weather service radar indicated a severe
thunderstorm capable of producing half dollar size hail and
damaging winds in excess of 65 mph. This storm was located near
selman...moving east at 20 mph.

Locations impacted include...
Selman.

Precautionary/preparedness actions...

Severe thunderstorms can produce tornadoes with no warning. Move
immediately to a storm shelter or sturdy building if a tornado
approaches.

[venture]

Just two severe storms left out there right now. One cell in Woodward County is trying to pulse up some.

[venture]

Fairly quiet day for the state today. Could have one or two severe storms impact far SW OK today. Later this evening and overnight might see a couple strong to severe storms form over Western OK and move through Central OK. Nothing to major right now, but the new 12Z NAM is tossing in the risk for some borderline severe stuff. HRRR keeps things dry through evening.

[Charlie40]

Whats it looking like for Friday evening? I have plans that evening and need to know what were looking at in terms of severe potential in order to know If i need to cancel and stay home or not. also Whats it looking like in terms of severe intensity for Saturday and Sunday? Thanks !!

[SoonerDave]

Hey, Venture, just saw a Rick Mitchell tweet saying that a couple of the tornadoes from yesterday were actually anti-cylonic. Is that just a weird aberration, or does it imply some unusual structure or shear in those storms?

Just wondering....thx.

-David

[ou48A]

Hey, Venture, just saw a Rick Mitchell tweet saying that a couple of the tornadoes from yesterday were actually anti-cylonic. Is that just a weird aberration, or does it imply some unusual structure or shear in those storms?

Just wondering....thx.

-David

From my OU meteorology lab class of over 30 years ago……..
At the time they said that about 2% of all Tornadoes in the northern hemisphere turned clock wise.

[SoonerDave]

Hey...

Seeing a couple of met types on Twitter saying things are really shaping up in a bad way for late week/Friday through Sunday severe-storm wise. Any of our resident gurus have any thoughts on how things are shaping up?

[ou48A]

http://www.spc.noaa.gov/products/exper/day4-8/

FRI APR 13 AND SAT APR 14.
VERTICALLY VEERING WIND PROFILES WILL PROMOTE THE
POTENTIAL FOR TORNADIC SUPERCELLS ALSO PRODUCING LARGE HAIL AND
DAMAGING WINDS.

[Charlie40]

http://www.spc.noaa.gov/products/exper/day4-8/

FRI APR 13 AND SAT APR 14.
VERTICALLY VEERING WIND PROFILES WILL PROMOTE THE
POTENTIAL FOR TORNADIC SUPERCELLS ALSO PRODUCING LARGE HAIL AND
DAMAGING WINDS.

That doesnt give enough information as to how widespread we are expecting. Will it be like last night just sporadic cells or will it be a full on tornadic supercells everywhere with multiple tornadoes on the ground at any given time?

[ou48A]

That doesnt give enough information as to how widespread we are expecting. Will it be like last night just sporadic cells or will it be a full on tornadic supercells everywhere with multiple tornadoes on the ground at any given time?

Someone who is far more qualified than I would need to answer that question but I get the feeling that the potential is there for a much more serious event than what we saw last night??????

If nothing else it’s going to move into a more populated area... It could impact more people.

These are 2 links to keep an eye on as forecast will become more focused each day.

http://www.srh.noaa.gov/oun/

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

[Charlie40]

Yeah, I am already well informed on the NWS site and SPC, Just wanting any model details as to what they are saying we might be in for. I am sure the local stations as well as NWS are waiting before putting out any strongly worded headlines yet. Just wanted to get an overall feel so I can prepare accordingly. Thanks Guys...

[venture]

Yeah, I am already well informed on the NWS site and SPC, Just wanting any model details as to what they are saying we might be in for. I am sure the local stations as well as NWS are waiting before putting out any strongly worded headlines yet. Just wanted to get an overall feel so I can prepare accordingly. Thanks Guys...

I got a couple free days...so I'll be sure to type up a more in depth discussion after the 00Z runs tonight.

[Charlie40]

I got a couple free days...so I'll be sure to type up a more in depth discussion after the 00Z runs tonight.

Thanks Venture, I gotta figure out the best plan for Friday and this weekend. I have to uncover the cellar in my garage still hopefully we wont need it but you know how it goes around Oklahoma

[venture]

Large area of heavy rain and storms moving through Northern OK. Gradually...and I mean very gradually LOL...moving to the southeast and south. Some isolated severe hail being detected. We'll see if they make the Metro for the morning rush. An outflow boundary is being pushed out over the OKC area and this can always set things up for additional storms later.

Main threat today will be well out west in the Panhandles. So not going to hit on much there. Tomorrow, different story. SPC's slight risk tomorrow is generally the western 1/4th of OK and this is a hatched area as well for potentially significant weather. Instability on Thursday will be moderate to high with CAPE values from 1500 to 2500 j/kg over much of Western OK. LI values aren't that extreme, generally -4 to -6. Wind profiles look favorable for rotating storms over most of Western & Central OK. Various indices are in alignment with severe parameters and generally indicate a supercell potential from 60-80% for any storm that does form. Storm motion is going to be SLLLLOOOWWW. Generally NE @ 10-15 mph. So if one of these gets over any location there is increased change of prolonged hail or other severe weather modes. Main threats then for Thursday will be tornadoes and very large hail over 2 inches.

Friday gets a bit closer to Central OK. SPC Slight Risk covers all over Western & Central OK with a hatched area from I-35 and back to the west...including most of the OKC Metro area. Instability looks better on this day with a general swatch of LI's from -4 to -8 and CAPE 2000+ j/kg generally from SW OK through Northern OK. Storm initiation would be during mid Afternoon to early evening, depending on the model you like (NAM holds things closer to the evening). Most parameters are in place for all models of severe weather and appear to be pretty favorable for tornadoes. Storm motion is looking like NE @ 30-35 mph...so more likely normal. There is a good likelihood that storms that do form would go severe this day. So main threat for Friday does look like tornadoes and hail again, a bit more likely than Thursday.

Saturday much of the same but a smidge to the east. There really isn't much to add here, the setup looks nearly identical to Friday. So if there isn't any ongoing storms to complicate things, Saturday could be another very active days. Main threats will be tornadoes and large hail.

Sunday...broken record, almost. Threat for severe weather this day but a little less certain which ongoing activity forecast by GFS. If things clear up, instabilities will climb and severe weather will be likely again for most of Oklahoma. Wind profiles look more linear which would push for more of a squall line like setup, however rogue storms going against the grain could rotate. Large hail and damaging winds are the main threats, but tornado threat will be around as well. Heavy rain for Central OK also looks possible which some areas getting over an inch.

Monday...severe risk is down but heavy rain chances are up. Many areas over Eastern OK could see over an inch of rain. Could see some low topped hailers over NW and Northern OK in the late afternoon before sun down under the upper low.

Things calm down for a bit after Monday...but it won't last...
Friday Apr 20th - Some storm chances over Western and Northern OK.
Saturday April 21st - Slight Chance for storms Western/Central OK.
Sunday April 22nd - Chance of storms, some severe, Western OK.
Monday April 23rd - Storms over Western & Northern OK, severe probable.
Tuesday April 24th - Chance of storms NW OK.
Wednesday April 25th - Slight chance of storms most of OK.
Thursday April 26th - Slight chance of storms most of OK.

[venture]

MESOSCALE DISCUSSION 0490
NWS STORM PREDICTION CENTER NORMAN OK
0235 PM CDT WED APR 11 2012

AREAS AFFECTED...SERN CO INTO THE TX PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 111935Z - 112030Z

COVERAGE OF THUNDERSTORMS CONTINUES TO INCREASE ACROSS SERN CO INTO
THE TX PANHANDLE. ALTHOUGH LARGE HAIL AND DMGG WINDS WILL BE THE
PREDOMINANT THREAT...AN ISOLATED TORNADO CANNOT BE RULED OUT. A WW
MAY BE NEEDED THIS AFTERNOON.

THE EARLIER STRATUS LAYER HAS ERODED...WITH AMPLE SUNSHINE
SUPPORTING A GRADUAL EROSION OF CONVECTIVE INHIBITION ACROSS A
GENERALLY MOIST AND UNSTABLE AIR MASS. A RECENT INCREASE IN VERTICAL
DEVELOPMENT OF CUMULUS HAS BEEN NOTED ON VARIOUS 1915Z SATELLITE
IMAGES AND SUPPORTING RADAR IMAGERY. SEVERAL SURFACE
BOUNDARIES/AREAS OF CONVERGENCE ARE SUPPORTING AN INCREASE IN
CONVECTIVE DEVELOPMENT...WITH UPSLOPE WINDS CLOSER TO THE HIGHER
TERRAIN...A STATIONARY FRONT ACROSS THE PANHANDLE THAT HAS BEEN
REINFORCED BY DIFFERENTIAL HEATING...AND A SUBTLE OUTFLOW BOUNDARY
ACROSS THE PANHANDLE AS WELL. SEVERAL SMALLER UPPER DISTURBANCES ARE
LIKELY BOLSTERING THIS CONVECTION. HOWEVER...WITH THE LARGER SCALE
RIDGE OVER THE AREA...STORMS HAVE CURRENTLY BEEN SLOW TO BECOME
SEVERE WITH LARGE SCALE SUBSIDENCE AND WEAK MID-UPPER LEVEL SHEAR.
WITH TIME...DEEP LAYER WINDS WILL STRENGTHEN WITH THE APPROACH OF AN
UPPER TROUGH...WITH STRENGTHENING IN LOW-LEVEL SELYS AS WELL. AS A
RESULT...ROTATING STORMS MAY BECOME INCREASINGLY POSSIBLE LATER
TODAY.

..HURLBUT.. 04/11/2012


ATTN...WFO...OUN...LUB...AMA...PUB...ABQ...

[ou48A]

I am hearing that if Friday night and early morning Saturday storms clear out soon enough that Saturday could be particularly dangerous weather day for our area.

[adaniel]

^^
That stinks. There are several large outdoor events, included the OU Spring Game, scheduled on Saturday.

[venture]

Friday and Saturday both look fairly significant right now.

[SoonerDave]

Friday and Saturday both look fairly significant right now.

Venture, I think you just channeled Gary England

[venture]

Venture, I think you just channeled Gary England

Let me find a blue shirt and red tie... LOL

Will post a new forecast update here this evening/early morning.

[venture]

New website is being pulled together a bit faster than I had planned. http://www.weatherspotlight.com is the new address. Live Event Chat is also loaded in to cover severe weather the next 3 days, though I won't be available for all of it.

[OKCisOK4me]

Even Reed Timmer said it could be interesting...

[venture]

Even Reed Timmer said it could be interesting...

He gets excited about water spinning in a 2-liter. :-P lol