General Weather Discussion - April 2014

[Dennis Heaton]

i think venture needs to publish a "oklahoma weather for dummies" book...

like!!!

[ou48A]

Oh Boy News 9 has us under a moderate risk of Severe weather on Wednesday BE PREPARE FOR THIS STORM!!!!

They are not alone

[venture]

They are not alone

I'm not seeing a moderate risk there...just an area of greater chance for higher end weather. Coverage density will determine if it gets upgraded. Right now it is at 15%. This is the problem with trying to compare the local media maps and the NWS products. They don't mean the same thing.

[ou48A]

These people^ do a great job


This is Severe Weather Briefing: Monday March 31, 2014 from the Norman National Weather Service office

“Don't be scared, be prepared”

[Anonymous.]

I'm not seeing a moderate risk there...just an area of greater chance for higher end weather. Coverage density will determine if it gets upgraded. Right now it is at 15%. This is the problem with trying to compare the local media maps and the NWS products. They don't mean the same thing.

Yea the local media using their own maps and categories is a real joke. Honestly there is no purpose to doing so.

[bchris02]

The Weather Channel has us at a TOR:CON 4 for Wednesday.

[venture]

The afternoon discussion is available from OUN: IEM :: AFD from NWS OUN

Some highlights since it is extremely long:

Tuesday

ECENT GUIDANCE HAS COME IN SLIGHTLY MORE BULLISH WRT INSTABILITY... SFC DEWPOINTS WILL CREEP INTO THE UPPER 50S... POSSIBLY LOWER 60S THROUGH THE LATE AFTN/EVENING. SBCAPE VALUES OF 1800 TO 2200 J/KG WILL POOL ALONG/NEAR THE I-44 CORRIDOR WITHIN THE TEXOMA REGION. 0-6KM WIND SHEAR 45-55KTS THROUGH THE EVENING ALONG THE RED RIVER WILL SUPPORT SUPERCELLS CAPABLE OF LARGE HAIL DEVELOPMENT.

EXPECT INITIAL DEVELOPMENT TO BE ISOLATED... STARTING LATE AFTN...3-5PM... WITH STORMS DEVELOPING ALONG THE WEAK COLD FRONT/DRYLINE AND SOME STORMS ALONG THE WARM FRONT AS IT LIFTS NORTH INTO CENTRAL OK.

TORNADO THREAT WILL REMAIN LOW AS LL WINDS DO NOT INCREASE UNTIL LATE IN THE EVENING... AFTER THE DRY LINE BEGINS TO RETREAT TO THE WEST. HOWEVER... THIS WILL NEED TO BE MONITORED CLOSELY... IN CASE ANY SUPERCELL THAT ENDS UP RIDING THE SW BOUNDARY MAY MAINTAIN ITSELF INTO THE EVENING... BECOMING CAPABLE OF PRODUCING A TORNADO IF IT IS ABLE TO TAP INTO THE LL WIND FIELD... PENDING THE CAPPING INVERSION ISN'T TOO STRONG.

Wednesday

STORMS WILL LIKELY DEVELOP MID/LATE AFTN ACROSS PORTIONS OF CENTRAL OK... EXACT LOCATIONS WILL BE DETERMINED BY HOW FAR EAST THE DRYLINE SURGES AND THE LOCATION OF THE WARM FRONT TO THE NORTH.

GIVEN SUFFICIENCY OF OTHER PARAMETERS... TORNADOES CANNOT BE RULED OUT... BUT WILL HINGE ON IMPACTS FROM LL FLOW... CURRENTLY 0-1KM SHEAR IS PALTRY IN ACCORDANCE WITH RECENT GUIDANCE 10 TO 15 KTS BY THE EVENING. HOWEVER... WITH GOOD UPPER LVL SUPPORT... 950 TO 850 MB S/SW WINDS COULD REACH 30-40KTS. WITH SUCH IMPRESSIVE INSTABILITY AND LOW LCLS... TORNADOES ARE NOT OUT OF THE QUESTION... AS THESE CONDITIONS MAY ASSIST IN OVERCOMING THE LOW LL SHEAR.

[warreng88]

2010... was that the year people were parking in the middle of the highway under bridges blocking everyone else from passing through?

[ou48A]

2010... was that the year people were parking in the middle of the highway under bridges blocking everyone else from passing through?

It happened last year too

[venture]

People hiding under overpasses has been going on for years. It isn't really a recent trend. Annoying as hell though when trying to get through and you end up trapped.

[Bunty]

The Oklahoman is hyping baseball+ sized hail. Is that looking like a probability? If so, are we looking at isolated hail cores or something widespread like the 2010 storm?

I try not to worry to death about such things until there is a tornado watch out.

[zookeeper]

SoonerDave: I remember April as the "storm" month as well. We're about the same age, too. I remember the "April showers bring May flowers" song. I think you're right about perceptions being different when you're young (or old!) but it's definitely different now.

As for all the "prepare now for this storm!" from some over-excited posters, there's really not much any of us can do to prepare for these storms this far in advance.

Another storm season. Ugh. They come and they go. Que Sera Sera (whatever will be, will be).

[SoonerDave]

The Weather Channel has us at a TOR:CON 4 for Wednesday.

If the Weather Channel and its moronic TOR:CON index were a piece of paper, I'd wad it up in to the most microsocopic ball possible, douse it in gasoline, set it afire, stomp out the ashes, scoop them up, and sprinkle them on Mike Morgan's oatmeal.

[bchris02]

If the Weather Channel and its moronic TOR:CON index were a piece of paper, I'd wad it up in to the most microsocopic ball possible, douse it in gasoline, set it afire, stomp out the ashes, scoop them up, and sprinkle them on Mike Morgan's oatmeal.

It makes more sense than KFOR's new threat level system. They should just stop with the "slight", "moderate", "enhanced slight" or whatever and come up with something that people will understand better.

[jn1780]

It makes more sense than KFOR's new threat level system. They should just stop with the "slight", "moderate", "enhanced slight" or whatever and come up with something that people will understand better.

I disagree. I don't think people have any more idea what a "4" vs a "5" means on the Tor-con scale than they do the difference between "slight" vs "enhanced slight".

[bchris02]

The thing is "slight" doesn't really mean slight when it comes to severe weather. There needs to be a scale that will give people an idea of what is possible and how likely it is. For instance, conditions that favor long tract, violent tornadoes (F4+) like May 20th, 2013 or May 31, 2013 should fall differently on the scale than conditions that favor hail to golf balls and a squall line, both which are considered severe events and could happen under a "slight" risk.

[PennyQuilts]

The thing is "slight" doesn't really mean slight when it comes to severe weather. There needs to be a scale that will give people an idea of what is possible and how likely it is. For instance, conditions that favor long tract, violent tornadoes (F4+) like May 20th, 2013 or May 31, 2013 should fall differently on the scale than conditions that favor hail to golf balls and a squall line, both which are considered severe events and could happen under a "slight" risk.

Well, I suppose you may have a point. However, speaking only for myself, I've never had any trouble keeping the types of weather straight. There has been many a storm where there were big tornadoes on some areas and that doesn't make me overlook that there might be hail at my place. To me, these might just be different aspects of a particular system. Since they so often come together, I don't really know why someone would want to separate them with a different severity system. To me, it is not so much about severity as likelihood. There is a "slight" risk of hail if it isn't likely to happen. A "severe" risk if it is probably going to happen. A "slight" risk of a long term tornado if it probably isn't going to happen but it could. A "severe" risk of a long term tornado means, to me, that is it much more likely to happen.

You worry much, much, much, much more about hail than I do and to be honest, I know that stuff is considered to be "severe," but I pretty much shrug it off. if it isn't a catastrophe, I don't sweat it. Sometimes I worry about cows if there is a bad hail storm.

[ou48A]

The thing is "slight" doesn't really mean slight when it comes to severe weather. There needs to be a scale that will give people an idea of what is possible and how likely it is. For instance, conditions that favor long tract, violent tornadoes (F4+) like May 20th, 2013 or May 31, 2013 should fall differently on the scale than conditions that favor hail to golf balls and a squall line, both which are considered severe events and could happen under a "slight" risk.

Most people are not as WX savvy as those who read this thread and most people are not near as tornado savvy as what most Oklahoman are.... While most of us on this thread don't really need it the WX channels Tor-Con index it is a useful tool to help reach a certain type of person who may not want to take the time to learn more.
Right or wrong the higher the Tor Con index is, the more ordinary folks will pay attention.

[venture]

Alright back to weather.

Tuesday

00Z Nam Discussion
Warm front will move back north overnight and through Tuesday. By late afternoon the front should be near the I-44 corridor and retreating further to the NW. Instability will be highest in the I-44 to I-35 portion of SW OK with CAPE values at or above 2500 j/kg and LIs around -7. Looks like dewpoints will be in the mid 50s to low 60s in this area. Convective inhibition will be absent once we get to late afternoon/early evening but quickly return after sunset. Overall coverage seems to be fairly isolated with the best area appears to be in the area of SW OK between I-44 and I-35 and then further SW into N TX. Forecast sounding (below) highlights a region that will be primed for severe weather as long as we get see storms initiate.



00Z GFS Discussion

Not many differences than NAM except for some modest position differences and more convection. Instability is all pretty much the same and the key areas as well. To compare, here is the sounding for the same general area in SW OK as the one above...



Main threads - large hail and damaging winds. Tornado threat will be there, but the window will be narrow since the boundaries will be retreating later in the evening. We'll have to see how things go. GFS does have more CIN and a stronger cap. So best to just go with a balance here and see how things progress tomorrow.

[venture]

SPC has gone pretty conservative for today. Smaller risk area, removed hatched section, and really holds most activity back due to weaker forcing.

...NWRN TX INTO SWRN OK...
STRONG HEATING WILL OCCUR W OF THE DRYLINE...WITH DEWPOINTS IN THE
60S F RETURNING NWWD AS SELY LOW-LEVEL FLOW BROADLY INCREASES ACROSS
THE SRN PLAINS. WEAK HEIGHT RISES WILL OCCUR DURING THE DAY AS THE
GREAT LAKES TROUGH DEPARTS...AND THIS WILL RESULT IN ONLY WEAK
CONVERGENCE AND FORCING FOR ASCENT ACROSS NWRN TX. THEREFORE...WHILE
MODERATE INSTABILITY LEVELS ARE EXPECTED...WITH FAVORABLE SHEAR
PROFILES FOR SUPERCELLS...THE SEVERE THREAT WILL BE MORE
CONDITIONAL. THE MOST LIKELY SCENARIO MAY BE FOR A LINE OF TCU TO
FORM ON THE LEADING EDGE OF THE MOISTURE RETURN/RETREATING
DRYLINE...WITH ISOLATED THUNDERSTORMS ERUPTING AS THIS AIR MIXES
INTO THE STEEP LOW-LEVEL LAPSE RATE ENVIRONMENT. THE MAIN ISSUE TO A
MORE SIGNIFICANT SEVERE THREAT WILL BE THE LACK OF PROLONGED FORCING
AND LIKELY MIXING OF THE MOISTURE. ALTHOUGH THE LOW-LEVEL JET
INCREASES FURTHER DURING THE EVENING...CAPPING WILL EXIST...THUS
STORMS SHOULD DISSIPATE AFTER SUNSET.

[Soonerman12]

ou48A... I completely agree with you. The torcon index does have its flaws but can be very useful. There was a torcon index of 4 in Missouri last week and guess what? Tornado warnings were issued. Last May the weather channel gave central OK a 6 and the EF5 hit Moore. People just need to understand how the Torcon works and what it means. I don't agree with a lot of the meteorologist on TWC (they seem like idiots) but Dr. Greg Forbes is very knowledgeable when it comes to tornados. Your absolutely right though, the torcon is good for people that don't know a whole lot about weather. (even though myself and the majority of people on this site know quite a bit)

Here is how the Torcon works,

TOR:CON Value Descriptions

8+ Very high probability of a tornado
6 - High probability of a tornado
4 - Moderate chance of a tornado nearby, but hail and/or high wind gusts possible
2 - Low chance of a tornado, but hail and/or high wind gusts possible
0 - Near-zero chance of a tornado or a severe thunderstorm

They have given Central and Eastern OK a 4 for Wednesday with all concern shifting to just Eastern OK Thursday with a torcon of 4-5. Even though a 4 is not a huge number (40% chance of a tornado) That is still in the moderate category and several tornadoes have touched down with a "4".

[bchris02]

I do think torcon is more useful to the average viewer than KFOR's system no doubt. I believe they had an 8 on May 31, 2013.

[SoonerDave]

ou48A... I completely agree with you. The torcon index does have its flaws but can be very useful. There was a torcon index of 4 in Missouri last week and guess what? Tornado warnings were issued. Last May the weather channel gave central OK a 6 and the EF5 hit Moore. People just need to understand how the Torcon works and what it means. I don't agree with a lot of the meteorologist on TWC (they seem like idiots) but Dr. Greg Forbes is very knowledgeable when it comes to tornados. Your absolutely right though, the torcon is good for people that don't know a whole lot about weather. (even though myself and the majority of people on this site know quite a bit)

Here is how the Torcon works,

TOR:CON Value Descriptions

8+ Very high probability of a tornado
6 - High probability of a tornado
4 - Moderate chance of a tornado nearby, but hail and/or high wind gusts possible
2 - Low chance of a tornado, but hail and/or high wind gusts possible
0 - Near-zero chance of a tornado or a severe thunderstorm

They have given Central and Eastern OK a 4 for Wednesday with all concern shifting to just Eastern OK Thursday with a torcon of 4-5. Even though a 4 is not a huge number (40% chance of a tornado) That is still in the moderate category and several tornadoes have touched down with a "4".

So what you're saying is that the harem-scarem index boils down to "low, moderate, or high"...help me understand how this is so much more informative to the casual observer than a "slight, moderate, or high" severe weather risk?

Sorry, but TORCON is just another way to frighten, drive website hits, and push ratings.

[Soonerman12]

Hey, I never said it was more useful than slight, moderate, or high. I simply said it has its flaws but can be useful.

[Soonerman12]

bchris02... If i'm not mistaking May 31st, 2013 was the El Reno Tornado. TWC gave a Torcon value of 6 on May 20th, 2013 when the Moore tornado hit.