Oklahoma Severe Weather Discussion - April 2013

[venture]

NWS Norman just launched a balloon to do a special midday sounding to see how things look upstairs. Should have details soon.

[venture]

Current radar has a bunch of crap from Arapaho north to Alva. The more interesting stuff is down around Childress. Norman Updated their afternoon graphic...

[BrettM2]

Current radar has a bunch of crap from Arapaho north to Alva. The more interesting stuff is down around Childress. Norman Updated their afternoon graphic...

So are they expecting most of the hail to be gone by the time it reaches OK county? Or will that just be after 7pm but the storms will be the same?

[venture]

So are they expecting most of the hail to be gone by the time it reaches OK county? Or will that just be after 7pm but the storms will be the same?

They are thinking mostly after 7PM. So the eastern edge of this is where they think things will line up at that time, there is another graphic for after 7PM.

[venture]

Here is the 18Z Sounding

[s00nr1]

Haha it's going to take a major effort to bust that cap pre-fropa. Good luck.

[venture]

Yeah the cap it just a monster still. Cap is stout down toward Fort Worth as well, but not as strong.

[venture]

We have one cell right now going up right along the front in Foard County, TX. A few other cells behind the front that are still trying.

[venture]

Watch Soon...



MESOSCALE DISCUSSION 0411
NWS STORM PREDICTION CENTER NORMAN OK
0214 PM CDT TUE APR 09 2013

AREAS AFFECTED...NWRN TX INTO MUCH OF CNTRL OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 091914Z - 092115Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...SCATTERED STORMS WILL EVENTUALLY FORM AND LARGE HAIL WILL
BE POSSIBLE. A WATCH MAY BE REQUIRED BEFORE 21Z.

DISCUSSION...AN ARCTIC FRONT CONTINUES TO SURGE SWD ACROSS TX INTO
WRN OK. ALONG THIS FRONT...OCCASIONAL CU HAVE RAPIDLY DEVELOPED AND
DISSIPATED AS SOURCE AIR GETS UNDERCUT. AHEAD OF THE FRONT...THE AIR
MASS HAS BEEN CAPPED.

HOWEVER...LATEST VISIBLE IMAGERY INDICATES CHANGING CHARACTER TO THE
CU FIELDS FROM NWRN TX INTO WRN OK NEAR THE FRONT. A DEEPER GROUPING
OF TCU HAS FORMED ON THE NOSE OF THE HOTTER AIR ACROSS NWRN
TX...NEAR A WEAK SURFACE LOW AND DRYLINE/COLD FRONT INTERSECTION
WHERE CAPPING IS NEGLIGIBLE. MORE RECENTLY...STABLE WAVE CLOUDS HAVE
MIXED ACROSS W CNTRL AND SWRN OK...SUGGESTING THE CAP IS BEING
LIFTED THERE AS WELL. WITH ADDITIONAL SURFACE HEATING AHEAD OF THE
FRONT...AND COOLING IN THE CAPPING LAYER...STORM INITIATION WILL
BECOME INCREASINGLY LIKELY OVER THE NEXT COUPLE HOURS.

ONE POTENTIAL PROBLEM IN REGARD TO LONG LIVED SEVERE CONVECTION IS
THE TENDENCY FOR THE FRONT TO UNDERCUT DEVELOPMENT OCCURRING ALONG
IT...ORPHANING THE INCIPIENT UPDRAFTS. THEREFORE...MUCH OF THE
CONVECTION MAY END UP BEING ELEVATED BEHIND THE FRONT.

..JEWELL/THOMPSON.. 04/09/2013

[Anonymous.]

Looks like some action may be getting started around Lawton.

[Anonymous.]

This will be the first SVR Thunderstorm Watch issued for OKC this year. (We have had 1 tornado watch)

[venture]

Even behind the front, storms are just have a tough time getting established. Heating is still on going down to the SW though so every little bit helps.

[SSEiYah]

Wow...


(credit: kfor.com)

[venture]

I wonder how much pressure the techs working on the FDR radar are feeling right now. LOL

Cell in NE Foard Co showing signs are getting stronger.

[Bunty]

Even behind the front, storms are just have a tough time getting established. Heating is still on going down to the SW though so every little bit helps.

From Oklahomaskies.net:

SEVERE WEATHER UPDATE: Special sounding out of Norman still showing a decent CAP in place which is inhibiting thunderstorm development for now. A strong cold front is racing south through western Oklahoma and will begin to overtake a dryline situated from southwest Oklahoma into west Texas. As this occurs, strong forcing along the front will result in a line of storms(squall line) with severe hail and wind possible. If we can get any storm to isolate itself, more significant severe weather including tornadoes will be probable. The most likely area for this to occur would be across southwest Oklahoma into western north Texas.

[Anonymous.]

The Frederick Radar actually came back on around an hour ago.

SSEiYah, not sure what you are saing 'wow' to, but that large circle is ground clutter near the radar - not convection.

[SSEiYah]

SSEiYah, not sure what you are saing 'wow' to, but that large circle is ground clutter near the radar - not convection.

ahh ok.

[venture]

Current Radar with front, wind, and dewpoint

[venture]

From Oklahomaskies.net:

SEVERE WEATHER UPDATE: Special sounding out of Norman still showing a decent CAP in place which is inhibiting thunderstorm development for now. A strong cold front is racing south through western Oklahoma and will begin to overtake a dryline situated from southwest Oklahoma into west Texas. As this occurs, strong forcing along the front will result in a line of storms(squall line) with severe hail and wind possible. If we can get any storm to isolate itself, more significant severe weather including tornadoes will be probable. The most likely area for this to occur would be across southwest Oklahoma into western north Texas.

Pretty much repeats everything we've been saying so far today.

The Frederick Radar actually came back on around an hour ago.

It went down again just after 2PM. OUN advised it was going to be on and off all afternoon as they work on it.

[Achilleslastand]

If someone is going to be away from their pc/tv this evening what radio station is recommended to get the best info?

[SoonerDave]

What's the speed of that front? Doesn't look like its going to take two hours to cross greater OKC..?

[venture]

Moving around 18 mph to the east. It is about 40 miles from downtown so it looks like 5pm there.

[venture]

Tornado threat pretty much done for today, could be a spin up ahead of the front if any storms happen there. Large hail the main story. Convective wind won't be a major deal either.



...SRN PLAINS...
CONVECTIVE POTENTIAL IS INCREASING ACROSS PORTIONS OK AND NW TX
WHERE MLCINH IS ERODING AHEAD OF SFC COLD FRONT...AMIDST FAVORABLY
STEEP MIDLEVEL LAPSE RATES AND DEEP SHEAR. REF SPC MESOSCALE
DISCUSSION 411 FOR MORE DETAILED NEAR-TERM ASSESSMENT.
ALSO...THOUGH POTENTIAL STILL EXISTS FOR SVR TSTMS WITH LARGE HAIL
AND DAMAGING GUSTS TO DEVELOP OVERNIGHT INVOF COLD FRONT...CORRIDOR
OF MAX HAIL COVERAGE AND SIGNIFICANT-HAIL PROBABILITIES HAS BEEN
TRIMMED NWD TOWARD RED RIVER. GEOMETRY OF KINEMATIC FIELDS SUGGESTS
MORE LINEAR EVOLUTION WITH TIME THAT WOULD DISFAVOR THE SORT OF
PERSISTENT SUPERCELLULAR MORPHOLOGIES OPTIMALLY SUITABLE FOR MORE
THAN ISOLATED SIGNIFICANT-HAIL THREAT OVER MOST AREAS. STILL..ANY
RELATIVELY DISCRETE CONVECTION THAT CAN DEVELOP AHEAD OF
FRONT...ESPECIALLY OVER NW TX/SRN-CENTRAL OK REGION...MAY PRODUCE
DAMAGING HAIL.

[SoonerDave]

Moving around 18 mph to the east. It is about 40 miles from downtown so it looks like 5pm there.

Ahhh, okay. I was under the impression it was moving much faster than that.

Clouds are reaaallly thickening up here in E. OK County....

[s00nr1]

18Z NAM ramping up precip amounts between 10pm tonight and 10am tomorrow. OKC metro is right around the freezing mark. A 1-2 degree shift one way or the other could make things very interesting.