Storms Gone And A Nice Week Ahead

Perhaps one good thing about our Spring Storm Season is that the storms usually leave the atmosphere clean and refreshed which will be the case this week. High Pressure will dominate North Texas weather for a good chunk of the week and we get to reap the benefits of low humidity and cooler evenings and mornings. 

Today's surface map shows the cold front which brought rain to North Texas over the weekend moving off  to the East. It will be replaced by a ridge of High Pressure, clearly seen over Arizona. The High will move toward Texas and bring a moslty calm, dry week.

Today: Mostly sunny, with a high near 74. Northeast wind between 10 and 15 mph. 

Tonight: Partly cloudy, with a low around 54. North northeast wind between 5 and 10 mph. 

Tuesday: Sunny, with a high near 78. Northeast wind between 5 and 10 mph. 

Tuesday Night: Mostly clear, with a low around 55. East southeast wind around 5 mph. 

Wednesday: Sunny, with a high near 80. South southeast wind between 5 and 10 mph. 

Wednesday Night: Partly cloudy, with a low around 58. South wind around 10 mph. 

Thursday: Mostly sunny, with a high near 79. South wind between 10 and 15 mph, with gusts as high as 20 mph. 

Thursday Night: A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 59. South wind 5 to 10 mph becoming west northwest. 

Friday: A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 74. North northeast wind 

Tornadoes In Oklahoma

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
411 PM CDT FRI APR 13 2012

OKC027-132130-
/O.CON.KOUN.TO.W.0009.000000T0000Z-120413T2130Z/
CLEVELAND OK-
411 PM CDT FRI APR 13 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 430 PM CDT FOR
CLEVELAND COUNTY...

AT 409 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
STORM WAS LOCATED NEAR NORMAN...MOVING EAST AT 25 MPH.

LOCATIONS IMPACTED INCLUDE...
NORMAN...STELLA AND LAKE THUNDERBIRD.

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 107 AND 115.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GET IN...GET DOWN AND COVER UP. TAKE COVER NOW IN A STORM SHELTER
OR AN INTERIOR ROOM OF A STURDY BUILDING. STAY AWAY FROM DOORS AND
WINDOWS.

High Risk Of Tornadoes For Oklahoma

The forecast we talked about in our previous post on Thursday has changed very little. There is a high risk of a major tornado outbreak on Saturday in Southern Kansas and South thru Oklahoma to very near the Red River. This does NOT include North Texas.

It's a pretty classic Spring storm system taking shape.A strong Low Pressure system with abundant moisture and instability ahead of it will combine with a Cold Front to produce the strong to severe storms on Saturday. This is a dangerous situation and residents in the aforementioned areas need to be alert and watch for rapidly developing storms on Saturday. Be cautions and check preparedness plans.

For North Texas, we won't escape this system either. By late Saturday night we should see rain and thunderstorms break out as the atmosphere will be "un-capped" and there will be plenty of moisture and lift for strong to Severe storms. However, at this time it appears that the main low will track to the north of us and that should mean we won't have the energy and lift for a widespread severe outbreak. That is NOT to say we won't have heavy thunderstorms, especially during the day on Sunday and the chance of tornadoes cannot be completey ruled out but will not be nearly as high as in the High Risk area.

We will keep an eye on things and issue updates as needed.

Strong Storms For the Weekend? Ingredients Coming Together.

Typical early Spring Weather for the South Central Plains states as a pretty active pattern is in place. Here in North Texas we have been influenced the past few days by a nearly stationary Cold Front that has been wobbling back and forth, from North to South. This will continue into the first part of the weekend and will lead to isolated, mostly afternoon and evening rain chances almost anywhere in North Texas. The chances of you seeing rain are small and it should not interrupt any outdoor plans. That all changes this weekend.

The Storm Prediction Center in Oklahoma has placed parts of North Texas under a Moderate Risk for Severe Weather, beginning late Saturday. This should not be taken lightly this time of the year.
A very strong storm system will be featured over the Four Corners area and this system will have whats called a "triple point axis". To simplify, this means that a Low Pressure System will include a Stationary Front (the one we've had all week), a Cold Front, and a Dry Line.

This generic map shows a Triple Point System

The counterclockwise rotation around the LOW will first cause the warm front to rapidly lift North allowing warm moist air to rush in. That will be followed by the Dry Line and then the Cold Front. It's like adding ingredients to a recipe and in this case it will cause lots of LIFT, Wind Sheer (winds changing direction and speed with height), a clash of air-masses, and that will all result in SuperCell Thunderstorms which lead to violent weather including Tornadoes.
The greatest Tornado threat will be near the axis of the Triple Point and on the image above that's where the arrow is pointing to. That's where the greatest areas of wind sheer will be and that's where storms are most likely to rotate. On Saturday this area will be in most of Oklahoma and into the Northwest portions of North Texas, west of DFW. On Sunday the entire system will shift further East and I don't want to predict at this point what Sunday will be like except to say that thunderstorms are a very good bet. I would like to see another couple of computer model runs before we get a good handle on Sunday. We will have another post by Friday afternoon.

Severe Weather Safety Tips

I ran across some Severe Weather Awareness tips from the National Weather Service to pass along.

Before Storms Develop

I heard there was a chance of severe storms today when I woke up, what should I do?

• Check the Hazardous Weather Outlook.
  
  The Hazardous Weather Outlook (HWO) can tell you when thunderstorms are expected to hit, where the best chance of severe weather will be, and it will provide a brief discussion of what is expected to happen.
   
• Visit the NWS Ft. Worth Website.
  
  The Enhanced Page will most likely provide some sort of informative graphic if severe weather is anticipated. It may give you an idea of where severe weather is most likely in an easy-to-understand graphical display.   

• "Like" us on Facebook.
  
  While we don't post our warnings to our Facebook site, we do often post information about upcoming and occurring weather events. We also highlight other ways to get prepared before the storm and announce Skywarn Storm Spotter training sessions.
   
• Check Your Kit:
  
  If you have a severe weather safety kit and/or NOAA All-Hazards Radio, you should make sure that everything has fresh batteries that work. You should check your radio, flashlight, etc. because they may become necessary later in the day. Make sure your cell phone is fully charged in case you lose power. If you don't have a severe weather safety kit, here are some suggestions to get you started.
    
• Review Your Safety Plan:
  
  If you have a severe weather safety plan you should review it. Make sure everyone in your family knows what to do in certain situations. Know where everyone will be during the day and make it clear what to do if severe weather impacts your location. Know where to seek shelter beforehand! If you don't have a tornado safety plan, review some safety tips and suggestions. Here is a link to a Red Cross family disaster plan in .pdf format.
    
• Find A Way To Monitor Weather Information:
  
  Whether it be via a television, AM/FM radio, the Internet, NOAA All-Hazards Radio, etc., continue to monitor weather information during the day for any changes in the situation. Set up a routine (i.e. check the weather information every hour on the hour). If you have access to the Internet or a NOAA Weather Radio, the NWS Fort Worth Hazardous Weather Outlook will be issued around 4 am and 4 pm daily with updates typically around 11 am and 9 pm.
  
  If you follow the steps above, you should have a good idea of when and where severe weather may strike, where you and your friends and family will be during that time, and know exactly what to do if severe weather should occur. Also, your severe weather safety kit should be complete and ready.

---

When A Watch Is Issued

Watches may be issued hours before a storm. The sky may be sunny when you first hear a tornado or severe thunderstorm watch. Remember, a watch just means that conditions are favorable for severe thunderstorms and/or tornadoes.

• Check Weather Information Again:
  
  Don't be caught off guard! While watches may be issued before storms form, thunderstorms may be developing when the watch is posted, or thunderstorms may be ongoing and moving into the area. By checking the weather information again, you will be aware of what is going on around you.

• Make Sure Your NOAA Weather Radio is Turned ON (If you own one):
  
  If your NOAA All-Hazards Radio was not already turned on, you should definitely make sure that it's on and the batteries are still working when a watch is issued. The radio will alert you if a warning is issued, so it is vital to have it on and working correctly.

• Consider Turning on a TV or AM/FM Radio:
  
  If you don't own a NOAA All-Hazards Radio, you may want to consider turning on a television to a local station, or turning on an AM/FM radio. A local television station is probably the best means of staying updated on the situation other than a NOAA All-Hazards Radio, or the NWS Ft. Worth website.

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When A Severe Thunderstorm Warning Is Issued

Do not ignore severe thunderstorm warnings! Severe thunderstorm warnings often precede tornado warnings, providing you with extra time to prepare for a dangerous storm. If there's a severe thunderstorm headed your way, you should monitor it closely, especially if a tornado watch is also in effect.

• Move Indoors and Away From Windows:
  
  Again, do not ignore severe thunderstorm warnings. Severe thunderstorms can produce damaging straight-line winds and large hail. It is important to move inside a sturdy structure and stay away from windows.

• Monitor Weather Information Continuously:
  
  Severe thunderstorms can and do produce tornadoes. Whatever method you use to stay up-to-date on severe weather information, make sure you do so. Being aware of what's going on around you is very important.

---

When A Tornado Warning Is Issued

Tornado warnings contain information that lists the cities and towns in the path of a tornado. While your National Weather Service strives to provide the most detailed and accurate information possible, there may be occasions when your small town or community is in the path of a dangerous storm, but is not listed in the warning text. This also holds true for television path forecasts. You should be cautious when using detailed forecasts of time and location. Because of the way radar works and how storms behave, these times and locations could be off by several minutes and several miles. Allow yourself plenty of time to get to your tornado shelter.

• Move quickly! Don't waste valuable time by trying to see the tornado. If you wait until you can see or hear it coming, it may be too late.
• Be sure you're dressed, and don't forget to wear sturdy shoes!
• Take your cell phone, car keys and identification with you.
• GET IN, GET DOWN, AND COVER UP!
  
  This is EXTREMELY important. If you are outside, get inside. If you're already inside, get as far into the middle of the building as possible. Get underground if possible. If you cannot, go to the lowest floor possible. Flying and falling debris are a storm's number one killer. Use pillows, blankets, coats, helmets, etc to cover up and protect your head and body from flying debris.
• DO NOT seek shelter under a highway overpass. They are not safe!
• DO NOT open doors or windows. This does not help!
• DO NOT go outside to find the tornado, even if you think it's far away!

TheWeatherGeek: Overnight Storms Possible

TheWeatherGeek: Overnight Storms Possible: The Easter Sunday rainfall that most of us in North Texas saw was caused mostly by a weak Cold Front that slid into the area just in time fo...

Overnight Storms Possible

The Easter Sunday rainfall that most of us in North Texas saw was caused mostly by a weak Cold Front that slid into the area just in time for a little daytime heating to kick off some good rains which we can always use.

The front is still in the area, though it has become defused and difficult to locate. What's left of the front will lift North today and it's possible that a few showers could break out along the Red River but the chances are slight.

Our next chance for rain will come late today and overnight and will be triggered by a strong disturbance that will swing out of the Rockies and into the area of the Texas and Oklahoma Panhandles. Very strong, Supercell thunderstorms will break out this afternoon in this area and will become the focal point for Severe Weather. There is the possibility of Tornadoes in this region from these storms.

The storms will begin moving southeast into the North Texas area but there are some limiting factors to them maintaining strength as they move towards us. The aforementioned warm front that will be moving north this morning will leave an area of subsidence (sinking air) in its wake. Also, the storms will weaken with the loss of daytime heating.

The storm complex moving out of the Oklahoma and Texas panhandles will eventually turn into a large group of thunderstorms know as a Mesoscale Convective System. These are fairly common nighttime occurrences in North Texas during the storm season. So what is an MCS? Think of it as a big "ball" of thunderstorms. The official Weather service definition is "A complex of thunderstorms which becomes organized on a scale larger than the individual thunderstorms, and normally persists for several hours or more. MCSs may be round or linear in shape".
They usually weaken as the move into more stable air which will be the case tonight.

Today's Severe Weather Outlook

So, the WeatherGeek forecast calls for Cloudy and warm today with just a very slight chance of rain in our norther counties and in in southern Oklahoma. Very heavy Thunderstorms this afternoon and tonight Northwest of the Wichita Falls area will move South and weaken as they do so. We can expect rain and thunderstorms anytime after sunset that will be heavier the further north and west you are. Tuesday calls for another chance of rain which we will cover in another post.

Next Round Of Storms Taking Shape.

We have enjoyed some very nice weather across North Texas after the dramatic weather on Tuesday. But, since this is Spring an active weather pattern is the norm.

A Cold Front will move into the Northwest portions of the area this afternoon and will become the focal point of our weather into the first part of Easter Sunday. This front will reach roughly the Wichita Falls/Abilene area by mid afternoon and a series of minor upper air disturbances will help the front lift the atmosphere and tap into abundant Gulf Moisture. The result, of course, will be Thunderstorms. 


This event will be different from Tuesday's violent weather for several reasons. There is not a real strong Upper Level Low in place which helps produce the wind sheer needed for Super-cell storms. This time the storms should be much more "linear" meaning they will stay near the southeastward moving front in more of a squall line. Also, for most of North Texas this event should see night-time storms which means they won't have the added daytime heating which leads to more violent storms.


So, the WeatherGeek forecast calls for thunderstorms to break out over the Northwest by mid afternoon along the Cold Front and SLOWLY move southeast. The core of the action should reach the DFW area just before or after midnight and spread east from there. The storms will begin to weaken early Easter Morning but don't be at all surprised to find rain as you are headed to Easter morning services. There will be scattered rain that could last into late Sunday afternoon.


The first and middle parts of next week look pleasant until our next system arrives by Thursday or Friday and this one figures to be stronger.

Rough Weather In The Metroplex

All the DFW TV Station are broadcasting Live and I advises to tune in to keep abreast on immediate changes in the weather.

Tornado Threat Increased a bit.

Thought I'd go ahead and issue an update since the National Weather Service has issues a Tornado Watch until
8pm tonight and as I write this a Tornado Warning for Johnson and Tarrant Counties until 1:30pm.


The wind sheer caused by a very strong upper level has caused the Tornado threat to increase. I don't believe this is a large outbreak situation but there indeed should be some Super-cell thunderstorms this afternoon and they always should be watched closely.

Storms Just West Of The Metroplex

As of 11am there were scattered thunderstorms, some severe, from the Red River near Wichita Fall all the down to the Brownwood area. These storms will continue moving East and will be in the Metroplex soon and on into East Texas after that. There is a Severe Thunderstorm Watch in place as indicated on the map.

Going to be A Stormy Day

The scenario we have been talking about for several days will all come together today as the weak Cold Front and a Strong Upper Level Low Pressure system combine to bring most all of North Texas a good chance of rain and strong to Severe Thunderstorms.

The forecast has become much simpler. As of 8am Thunderstorms were already firing from Abilene to Wichita Falls. This is  in response to the Cold Front which is now headed east with a strong push from the Upper Level Low. These storms will hold together and actually increase in coverage as the day goes on and daytime heating further adds to instability. 
 
As the Low it's self approaches look for the storms to become more Severe because the Low brings with it a lot of Cold air in the upper levels. This will also aid in the development of hail in some storms. There is not a lot of wind sheer with this system and so Tornadoes are not a huge thereat but an isolated tornado or 2 can never be ruled out because there could be a few Super Cell thunderstorms.. 


The system should clear the Eastern part of the area by late evening.

Forecast Looks To Be In Good Shape

The forecast the WeatherGeek put on the table in last nights post is still looking like a good bet. The LOW off the Texas Coast we talked about has moved northeast today and is causing widespread rain and heavy thunderstorms over East Texas. Some of this might reach into the Paris, Sulphur Springs, Tyler area but not much more west than that. There is a Severe Thunderstorm Watch for that Area until 11pm.

As mentioned yesterday, my concern with this LOW is that it will rob the atmosphere of moisture ahead of the Strong Upper Level Low moving into the New Mexico area. The National Weather Service finally made mention of this possibility in their morning discussion (as I pat myself on the back for beating them to it.). 

It's still difficult to tell how much of a factor this will be.

It's a given the 2 things will happen today and tomorrow. A Dryline and Cold Front will join forces in West Texas to kick off a round of very heavy Thunderstorms to the west of the DFW area. These might stay together long enough to make it to the I35 area but I'm thinking more likely they stay west of there.

The real show will be overnight and into Tuesday when the main LOW to the west becomes "cutoff" and moves over us. Again, I think it's possible that the Thunderstorms currently in East Texas might take away some of the punch this system has but we should still still rain and thunderstorms, some strong, across all of North Texas overnight and again on Tuesday. It won't rain all the time but there could be several rounds. The official forecast calls for a 60% coverage for DFW on Tuesday and that sounds about right.

After this system moves out we should have dry and still slightly warm weather.

Very Complicated Forecast

Yesterday, the WeatherGeek talked about ingredients coming together for a hot Sunday and rain on Monday. We have had our Sunday hot temps reaching  90 just west of DFW. The rain and Thunderstorms are becoming more of a tough call with each passing hour it seems.


This is what I do know. North Texas is in the path of a Strong Upper Level storm system that will bring rain to most, if not, all of us between Monday afternoon and Tuesday afternoon. 
It's just the type of complicated pattern that challenged me to start this blog in the first place :).

Weather Map as of Sunday Afternoon Shows a Front to our West and a little Rain the Gulf. Both will play a role in  our weather.

Here are the determining factors:


1) Strong Upper Level Low, currently over the Desert Southwest, will spin-off a piece of energy know as a "Closed Low". Think of this as a low pressure system that breaks off from the main energy and jet stream. These are always difficult to judge because they tend to have a mind of their own as to the track they will take.


2) A Dryline and Cold Front (not real cold, more of a wind-shift line) will move out of West Texas in response to the approaching Upper Level Low..


3) A new Low forming off the Texas Coast.


So how will these 3 factors play in our weather? I will try to be as basic as I can but keep in mind that this is a very complicated pattern. The National Weather Service afternoon discussion this afternoon was one of the longest I have read in a long time and almost gave me a headache.
First, the Cold Front/Dryline will move East tomorrow afternoon. There will not be a huge amount of push behind it so it's still tough to tell how far East this will make it. Regardless, there is plenty of moisture and instability in place to fire off thunderstorms, which should form into a squall line and some will be strong to Severe. I will keep these storms West of DFW until the early evening hours and therefore don't think this will lead to much rain, if any, East of I35.
The Low off the Texas coast will also be moving Northeast and should cause storms to break out over Southeast Texas and maybe even up to the Sulphur Springs, Paris areas. This should be in the afternoon/evening hours. Don't expect this to be a major Severe outbreak at this time. This low could play a major role in what happens Tuesday morning into the afternoon. This is ONLY a hunch on my part and the National Weather Service has not talked about this in their afternoon discussion. I have seen in the past where  Low Systems that form in the Gulf with an approaching Storm System to our West will rob the atmosphere of moisture for the storm in the West to work with. If this pans out it means that the only rain we see would be from the Low off the Texas Coast and this is not a real strong system so it would lessen the rain. However, if this Low has little impact on the moisture available for the Strong Low coming at us from the West then we will likely see much more activity and it could indeed be strong Tuesday morning into the afternoon.


There are a lot of "if's" there which is the fun thing about predicting Weather.