After a relatively busy, yet memorable/somber May, we enter June which typically is the last month of our peak season for severe weather. We tend to transition to a pattern that is more dominated by Northwest flow and MCS's from Colorado and Kansas. We'll have to wait and see though since we have had a very wet May but also a delayed storm season.
Current Conditions
Norman Warning Area Map
Tulsa County Warning Area Map
Tornado Warning | Tornado Watch | Severe Thunderstorm Warning | Severe Thunderstorm Watch
Red Flag Warning | Fire Warning | Severe Weather Statement | Special Weather Statement
Hazardous Weather Outlook | Fire Weather Watch Other Color Meanings: Web-Based Watch/Warning/Advisory Map Colors - NOAA's National Weather Service
Oklahoma Mesonet Current Conditions Red - Air Temp, Green - Dewpoint, Barbs - Wind Speed/Direction, Gray - Gusts, Blue - Precip since Midnight
Step 1) Go the main page: High-Resolution Rapid Refresh (HRRR)
Step 2) Click on 3km HRRR-CONUS hourly
Step 3) Under Domain select SC for South Central US
Step 4) Look at the time frames available. Usually if it isn't through Hour 06 yet, I'll just go up to Date and select the previous time.
Step 5) Depending on what you want to see you can click on the specific time or to loop all the times available you'll see a Check Mark under loop. You can click that to loop them all.
Tutorial: WHAT SPC PERCENTAGES MEANS IN RELATION TO CATEGORICAL RISK LEVEL Tutorial: HOW TO READ SKEW-T CHARTS
The main Skew-T is your 3 lines with wind barbs on both sides. So the lines first off. Solid is air temp and dashed dewpoint. The dotted line is the temp of the parcel of air as it goes up. So follow that up. If the solid line is to the right of that dotted line that is air that is warmer than that parcel and the parcel won't rise. Also known as your cap. When the air parcel gets warmer than air temp that area between the solid line and dotted line, that is your CAPE. This also shows that the parcel of air will continue to rise up until it meets the air temp again. Here is a good video to help explain it...
Okay so we are looking at that and we can things are going to be unstable with a lot of CAPE. Move of to the wind barbs on the right, that is your wind direction and speed at the various heights. This is also how we detect shear. The two main kinds are going to be speed shear and directional shear. In this exactly we are seeing surface winds out of the SE/SSE, or backed winds as you'll read often, and then they change directions to the SW and WSW as you go up in height. Good example of directional shear. Speed shear is when you have wind speed increase as you go up. We have some of that here as well. All in all this says, good shear. Sometimes you have to be careful of too much shear or speeds being too high in the upper levels because that can just rip updrafts apart.
So we got an unstable atmosphere and wind shear. Finally the squiggly line that is the hodograph. Used to find things like shear vectors and storm relative winds. These are good to help determine if you are going to be dealing with splitting storms and such. Typically in class right turning supercells we look for the hodograph to arch from the center to the right. Which we have here...for the most part. I won't get too much more into it right now, but googling should bring up a ton of resources on it.
So now we get down to the values. A lot of these are open to interpretation and how they play into storm formation, severe storms, and tornadoes. I'm just going to hit on a few of the variables instead of every one, otherwise this will be a book and probably confuse more than need be. Going left to right since these aren't perfect columns.
LI - Lifted Index. Negative is unstable, usually want lower than -4 for severe.
KI or K Index you usually want mid 20s for storm development and over 35 for strong development.
Equil P - That is where your air parcel meets the air temp again after getting warmer than it.
HAIL - Subjective to this sounding project on estimated hail size.
ConvT - Convective temperature or air temp needed to break cap without much forcing. This is more important in summer usually.
Lapse Rates also need to be looked at, in this care the value is favorable for severe weather.
SRH this is the Storm Relative Helicity in the first kilometer of air from the service...or your low level shear. This is also modified by the direction storms will move. Usually anything over 150 would be pretty significant.
SWEAT Index helps highlight severe storm potential. Usually 300-500 is what we look for, anything higher is significant.
TTI or Total Totals is another index looked at for storm development in general. Mid 40s are usually looked at for storm development, anything higher would indicate a more volatile setup.
Storm Dir/Speed - This is your storm direction in degrees and this is where the storm is coming from. So the example here is ~ 225 degrees which translates into moving NE. Speed is in knots so take the value and multiply by 1.15 to get MPH.
CapI - Strength of cap. Usually you want 2 or lower to help keep somewhat of a lid on things early. Over 4 requires a nuke to get rid of, less would lead to grunge fest.
LCL - Lowest cooling level. This is the atmospheric pressure height (measured in millibars) where the air can condense and form clouds. So a high number here means the level is lower to the ground and better chance for surface based convection. If you see numbers lower than say 850 mb, you are talking mostly high based elevated storms. Tornadoes need high LCL values (or lower cooling levels) since they are tied with surface based storms in most cases.
Sup Potential: Value specific to this product estimating percentage chance if any storm forms that it will be severe.
Precip Water measures the amount of water in the air. Usually you don't want it more than 1.5 or 1.75 for severe storms otherwise you are looking at just heavy rain. Lower than say 0.75 and its going to be too dry for much precip.
CAPE most are familiar with. Anything over 0 is unstable. Depending on the season will determine how much you need. Usually anything over 2000 j/kg is very unstable. However as we get into late spring/summer you'll see values over 5000 but not get anything. Even though its extremely unstable, it doesn't do any good without lift or something to break a cap.
CINH: Convective inhibition. Usually when you start getting lower than -100 you have issues getting anything going.
0-1km Shear - Like earlier this is your shear in the first kilometer of air, but this isn't storm direction dependant. When you start getting over 100 to 150 in this department you need to start being vigilant.
1km EHI or Energy Helicity Index another way to measure energy/shear. Usually more than 2 or 3 is pretty high.
That's pretty much the main ones without going longer...which I already went a bit too long. We can get more specific about the individual values if more clarification is needed. I went pretty general and with a broad brush on a lot of these. This is mainly to give you an idea of what to look for. The main thing to remember is that so much goes into this, and hopefully this is another example of how much there is, that you can't focus on just a few of these and figure big time storms. Think of it as a recipe. You have to have near perfect amounts of each to get a good tasting soup...otherwise you are just left with a pot full of odd smelling/looking/tasting water.
Re: Oklahoma Severe Weather Discussion - June 2013
Well the new watch technically goes into tomorrow, so will put it here.
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 269
NWS STORM PREDICTION CENTER NORMAN OK
1145 PM CDT FRI MAY 31 2013
THE NWS STORM PREDICTION CENTER HAS ISSUED A
* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
CENTRAL OKLAHOMA
* EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 1145 PM
UNTIL 500 AM CDT.
* PRIMARY THREATS INCLUDE...
SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2
INCHES IN DIAMETER POSSIBLE
A FEW DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 35
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES NORTHWEST
OF CHICKASHA OKLAHOMA TO 40 MILES SOUTHEAST OF CHANDLER OKLAHOMA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU9).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 262...WW 265...WW
266...WW 267...WW 268...
DISCUSSION...VIGOROUS STORM DEVELOPMENT CONTINUES ABOVE A
CONVECTIVELY GENERATED COLD POOL ACROSS CENTRAL OKLAHOMA. THIS IS
ALONG A MID-LEVEL BAROCLINIC ZONE WHICH MAY LIFT SLOWLY
NORTHWARD...BEFORE SHIFTING BACK SOUTHWARD OVERNIGHT...AS AN UPPER
IMPULSE TURNS EASTWARD OUT OF THE SOUTHERN HIGH PLAINS. GIVEN THE
CONTINUING PRESENCE OF VERY STEEP MID-LEVEL LAPSE RATES AND SIZABLE
MOST UNSTABLE CAPE...ALONG WITH AMPLE CLOUD BEARING LAYER
SHEAR...THE RISK FOR THUNDERSTORMS WITH SEVERE HAIL...PERHAPS A
COUPLE OF STRONG WIND GUSTS...PERSISTS OVERNIGHT.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 26030.
Tornadoes
Probability of 2 or more tornadoes
Low (10%)
Probability of 1 or more strong (F2-F5) tornadoes
Low (<2%)
Wind
Probability of 10 or more severe wind events
Low (20%)
Probability of 1 or more wind events > 65 knots
Low (10%)
Hail
Probability of 10 or more severe hail events
Mod (30%)
Probability of 1 or more hailstones > 2 inches
Mod (30%)
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
Re: Oklahoma Severe Weather Discussion - June 2013
Nah, that's why I wanted to get this thread up because people were asking in the chat.
Below are some images showing the supercell composite index which just highlights chances for storms to be severe if they occur, not a guarantee. Looking at chances of precip we are looking at overnight complex late Monday into early Tuesday. Tuesday Afternoon/Evening Central and Western OK storms. Wednesday storms West, central, and Northeast. Thursday West into central and East. Saturday NW to SE. Monday early Cental.
Re: Oklahoma Severe Weather Discussion - June 2013
Latest trend shows the line moving back to the south now, with the individual cells still moving SE. Extreme flooding is going to develop - please be safe!
Re: Oklahoma Severe Weather Discussion - June 2013
This flooding could possibly go down as the worst in OKC modern history. This will rival and probably pass the N OKC / Edmond event a few years ago in June.
Re: Oklahoma Severe Weather Discussion - June 2013
Originally Posted by venture79
Latest trend shows the line moving back to the south now, with the individual cells still moving SE. Extreme flooding is going to develop - please be safe!
Well, darn, Stillwater gets bypassed again. Much of that area only got under an inch of rain, Friday. Sure sorry, though, that much of OKC is getting overly deluged, besides having the tornado damage and deaths to deal with.
I heard it said that officially OKC set an an all time record for total rainfall in May with around 14 inches.
Re: Oklahoma Severe Weather Discussion - June 2013
Originally Posted by Bunty
Well, darn, Stillwater gets bypassed again. Much of that area only got under an inch of rain, Friday. Sure sorry, though, that much of OKC is getting overly deluged, besides having the tornado damage and deaths to deal with.
I heard it said that officially OKC set an an all time record for total rainfall in May with around 14 inches.
Bunty, don't knock it. An inch of rain isn't something bad with June on the horizon. From the way it's looking on radar, you could still get more tonight.
Re: Oklahoma Severe Weather Discussion - June 2013
I wanted to touch on the long term forecast again. Looking at the GFS tonight for the period going beyond next Sunday (week from tomorrow) we are looking at storm chances returning for every day through Sunday the 16th. Instability will be moderate to high each day, but that doesn't mean everyone will get storms each day. It also doesn't mean everyone will get severe weather. As we get into summer it normally takes higher amounts of instability to get severe weather than it does in Spring. The good news in all of this, temps looks like they won't jump into the 100s anytime soon across most of the state - limited to just the West/Southwest part.
Re: Oklahoma Severe Weather Discussion - June 2013
I just wanted to point out, I took a drive through Edmond 30 mins ago(yes, I know people shouldn't be out driving, but I did anyways, because thats what I do), and I saw about 3 businesses with their sprinkler systems running. NO JOKE! Not that it really matters at this point in time, but it matters in the sense that if they're doing it when it is raining this much, they'll do it when every drop counts and we have a storm(during that time) that would allow them to take a weeks break of watering.
Re: Oklahoma Severe Weather Discussion - June 2013
Originally Posted by venture79
I wanted to touch on the long term forecast again. Looking at the GFS tonight for the period going beyond next Sunday (week from tomorrow) we are looking at storm chances returning for every day through Sunday the 16th. Instability will be moderate to high each day, but that doesn't mean everyone will get storms each day. It also doesn't mean everyone will get severe weather. As we get into summer it normally takes higher amounts of instability to get severe weather than it does in Spring. The good news in all of this, temps looks like they won't jump into the 100s anytime soon across most of the state - limited to just the West/Southwest part.
And I assume that all of the wet weather we are getting now should temper potential summer heat unlike the last couple of years.
Re: Oklahoma Severe Weather Discussion - June 2013
Originally Posted by Plutonic Panda
I just wanted to point out, I took a drive through Edmond 30 mins ago(yes, I know people shouldn't be out driving, but I did anyways, because thats what I do), and I saw about 3 businesses with their sprinkler systems running. NO JOKE! Not that it really matters at this point in time, but it matters in the sense that if they're doing it when it is raining this much, they'll do it when every drop counts and we have a storm(during that time) that would allow them to take a weeks break of watering.
Plupan, I understand your point but I don't really see any major issue during the situation we're having tonight. Our water supply is filling up and overflowing much faster than a few sprinklers can deplete it. I'm sure the businesses where that was happening were wishing they could stop it too. It's costing them money.
Re: Oklahoma Severe Weather Discussion - June 2013
Originally Posted by ljbab728
Plupan, I understand your point but I don't really see any major issue during the situation we're having tonight. Our water supply is filling up and overflowing much faster than a few sprinklers can deplete it. I'm sure the businesses where that was happening were wishing they could stop it too. It's costing them money.
No I understand it doesn't matter, but what I'm saying is, if they're doing it now, there will be a point when our water levels are low and we'll have a storm roll through that will give some good rain and provide enough water where people won't have to water their yards for about a week, but won't fill up the lakes. They will still water anyways.
But hey, you got a good point with the money thing. I'm sure the city likes it lol, if they even notice ;P
Re: Oklahoma Severe Weather Discussion - June 2013
Originally Posted by Plutonic Panda
No I understand it doesn't matter, but what I'm saying is, if they're doing it now, there will be a point when our water levels are low and we'll have a storm roll through that will give some good rain and provide enough water where people won't have to water their yards for about a week, but won't fill up the lakes. They will still water anyways.
But hey, you got a good point with the money thing. I'm sure the city likes it lol, if they even notice ;P
The city still has water use restrictions in place. As long as they are obeying the restrictions, I don't have a problem with it.
Re: Oklahoma Severe Weather Discussion - June 2013
Seeing things get stretched out now. Southern fringe of the line over us is more so stay in place instead of going further south - a few boundaries coming out from them that could play into storms tomorrow down south. Northern edge is building back to the NNE. Also the cold front is lighting up now from Enid back to SE of Leedy.
Re: Oklahoma Severe Weather Discussion - June 2013
Originally Posted by venture79
Seeing things get stretched out now. Southern fringe of the line over us is more so stay in place instead of going further south - a few boundaries coming out from them that could play into storms tomorrow down south. Northern edge is building back to the NNE. Also the cold front is lighting up now from Enid back to SE of Leedy.
It's still just amazing how it just keeps rebuilding continuously over basically the same area for hours and hours.
Oklahoma Severe Weather Discussion - June 2013
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Re: Oklahoma Severe Weather Discussion - June 2013
Originally Posted by Anonymous.
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