Showing posts with label dew point. Show all posts
Showing posts with label dew point. Show all posts

Tuesday, July 10, 2012

7/10 - 11:55pm - A Tale of Two TV Stations

Let's start with weather first, shall we? Today was hot in Louisville, much hotter than anticipated because dry air that made its way into the area allowed temperatures to rise quite a bit. We're talking about a high temperature that was 95 degrees today, which even though is very warm, it was still cooler than what we experienced during last week's massive heat wave. Tomorrow should be a little cooler as moister air moves in again from the south.


Daily rain chances will be ramping up Thursday in Louisville as a trough develops to the west of the Mississippi River. It's already been raining in West Tennessee a bit this week, but more is on the way through the weekend as this trough gets its act together and a warm front moves northward. The rain is still needed in West Tennessee as drought conditions persist throughout the region. This rain will keep temperatures down in both regions, which is good news after all the heat! Between this past morning and Sunday morning there could be over 6 inches of rainfall  in West Tennessee and North Mississippi according to the Hydrometeorological Prediction Center (HPC). Flash flooding issues may crop up in some of the heavier thunderstorms.


Now, to the two TV stations. The first TV station in question here is WBBJ-TV in Jackson, TN where I'll be at on Saturday and Sunday night doing weather. It's been nearly three months since I've been on air in West Tennessee so I'm happy to be coming back this weekend and next weekend too for the Saturday night shows! The second TV station in question is WAVE-TV in Louisville. Today I went in to meet with Kevin Harned and the gang at the station and came out a WAVE 3 Weather intern. This has been "in the works" for awhile but today it was made official and I'm extremely excited to be sharing this news! I'll be at WAVE a couple days a week until mid-August. My duties will be mostly web-based with social media, blogs, etc, but I'll also assist with any needed TV-related tasks. I'm so thankful to be able to intern at the station I grew up with and to work with such a great team of meteorologists!

Thursday, June 28, 2012

6/28 - 11:30am MDT - Waking Up in Nebraska

After storms in Northeast Colorado yesterday became contaminated by storms coming off the Front Range, we decided to head east to be ready for today's chase. After waking up in Ogallala, Nebraska this morning we're rested up for a relatively leisurely day without too much driving since we're already pretty much in our target area for the day. The Storm Prediction Center has a general thunderstorm risk out for Western Nebraska, Northeast Colorado, and Northwest Kansas today with a 5% severe wind risk.

The focus today will be a cold front that's slowly moving through the region today. Winds around this frontal boundary may shift out of the east a little bit and that's where we'll position ourselves since the best shear will be where that happens. Dew points will be in the 60's across Central Nebraska this afternoon with slightly lower readings to the west. These surface winds, while weak, and the moisture should be more than enough to get some storms going.

Winds aloft are a little less certain since they may change throughout the day. Early on this morning winds at 500 mb (18,000 feet) were almost westerly across the western half of Nebraska, but already we've seen a shift to the southwest. While not terribly strong, the winds up there could have just enough punch to get storms to become severe. Small embedded shortwaves within the flow may enhance these winds a bit in some areas too. By 6pm MDT tonight the RAP model (right) still has these winds out of the southwest aloft, so that's some good news. The thinking at this point is that the shear won't be high enough to keep storms from merging together and being clustered, but we'll see how that plays out.

Follow me on Twitter and Facebook for constant updates during our chase!

Sunday, June 24, 2012

6/23 - 11:30pm MDT - Who's Ready to Go North?

Our tour guests have been through orientation and now we're ready to set off for our northward journey tomorrow from Denver to the region where Wyoming, Nebraska, and South Dakota meet. This area will be on the northwestern side of the large ridge in the middle of the country and on the eastern side of the trough coming onshore from the Pacific. This means there will be southwesterly winds aloft, at 500 mb or 18,000 feet, to hopefully bring in some drier air so that instability will increase when it contrasts with the warm, moist air at the surface that will be rising into it. While weak in speed, the winds up there will also increase wind shear because they will be at odds with the easterly and southeasterly winds at the surface. This will increase helicity a little bit, which is a corkscrew-like rotation in the atmosphere that is good for fueling rotating thunderstorms.

Moisture shouldn't be too big of a deal since dewpoints will be in the 60's, but we'll be eying the potential for issues with the the cap, which is a warm layer of air above the surface that inhibits thunderstorm development. All the warm air in place over the central part of the country breeds strong capping since the warm air is in place at the mid levels, but the models are suggesting that this cap may be overcome tomorrow afternoon and lead to some isolated storms. At this point there is nothing that suggests any storm that forms will be anything past marginally severe, but the helicity that the NAM model is picking up on above is certainly worth keeping an eye on.

The Storm Prediction Center has a general thunderstorm risk out for our target area tomorrow with no chance for severe weather. Since storms will be pretty isolated and in a fairly unpopulated area, it may not be worth it for them to issue any sort of severe risk with a setup this marginal. We'll see how things have developed overnight when we set out in the morning though. A secondary low may try to form in western South Dakota tomorrow according to the NAM and that may influence our decision on where to go if it forms since the best winds will be just to the north of the low center. Hopefully we'll see some storms!

Follow me on Twitter and Facebook for the latest tomorrow!

Friday, May 25, 2012

5/25 - 11:50am CDT - A Grand Finale

Ever since earlier this week we've had our eye on today's setup in Central Kansas. The moisture return, a low developing over Southwest Kansas, and upper-level wind support all kept us coming back to look at the models to see how it was shaping up. For a while it looked like the cap, or a layer of instability-inhibiting warm air aloft, was going to surpress storm formation but now we're seeing a situation where there will be just enough break in the cap to allow for a few isolated supercell storms to form. To get surface heating today to break that cap we need to clear out the clouds across Kansas first. A push of dry air at around 10,000 feet is currently moving from Southwest Kansas to the northeast and is eating these clouds for breakfast as you see in the satellite image to the right. We expect this to keep moving throughout the day and hopefully it will clear out the clouds in time to get some serious surface heating going.

The big story here today is the moisture return. For the first time this week we are seeing a situation where dew points will surge into the mid to upper 60's. Yes! This much-needed moisture will be the fuel for storms this afternoon and should give us a much better show than the moisture-deprived low-precipitation storms we've been seeing lately. While we don't have this moisture in the area quite yet, it's streaming in like crazy right now. Strong easterly and southeasterly winds are blowing this moisture into Kansas from Missouri and Oklahoma and will continue doing so throughout the day. Having mostly easterly winds in Kansas right now is a very good thing because this is creating just about optimal low-level shear for rotating supercell storms.

Speaking of wind shear, this will create quite a bit of helicity, or a corkscrew-like rotation of air in the atmosphere. When you combine helicity with instability in an equation you get the Energy Helicity Index (EHI). As I've said before I think that indicies and parameters can be distracting since human analysis is always better than a formula, but EHI seems to be fairly reliable since it is so basic and relies on two very basic ingredients. This afternoon's EHI values in Kansas will be the highest we've seen out here this season according to the Rapid Refresh model. That's some great news for storm chasers because higher EHI values typically correlate with enhanced tornado potential.

The Storm Prediction Center has a Slight Risk for severe storms today from Iowa to the Texas Panhandle and within that a 5% tornado risk in Kansas. This is quite the change from the previously non-severe "general thunderstorm" outlooks that they had been issuing for today because of the concern that strong capping may inhibit storm development. Today is our last chase day out here for Tour 3 and my last day out here until I come back for a week in June. If we could see some good storms today that'd be a great end to the first part of my trip! Tonight once we're finished chasing we'll be traveling back to Oklahoma City where I'll fly back to Louisville from tomorrow morning.

Follow up-to-the-minute reports on our chase on my Twitter and Facebook accounts!

Thursday, May 24, 2012

5/24 - 11:30am CDT - A Repositioning Day

Yep, there's a Moderate Risk for severe storms in parts of Wisconsin, Minnesota, and Iowa today according to the Storm Prediction Center. It's too bad because we simply can't chase there due to the amount of trees and vegetation along with a considerable distance from Oklahoma City where we need to be tomorrow night. Here's the plan then: We're going to drive south from Des Moines to Kansas City and then cut west in Kansas for this evening when we could see some overnight storms with lightning in that region.

Tomorrow still looks interesting to say the least. Right out front I need to say that this setup has a very high bust potential because of all the capping that will be in place. Warm temperatures of 10 degrees Celsius and higher at 10,000 feet (700 mb) will act as this capping mechanism because it will inhibit warm air from rising buoyantly into the layers above for thunderstorm formation. With that said, this cap may weaken just enough for a couple of storms to fire up in Kansas tomorrow. They would likely be very isolated due to the capped environment, so that's definitely a plus here.

We all know by now that the models have not been handling moisture very well lately and tomorrow probably won't be any different. The NAM model has dew points of 65 degrees Fahrenheit and higher in Central Kansas at 4pm CDT. If this is overdone and we see dew points between 60 and 65 degrees it still wouldn't be too bad. An area of low pressure smack dab over the middle of Kansas should help bring some of this moisture in and also create a considerable amount of wind shear for rotating storms, especially near the warm front just south of the Nebraska border. Again, this is all if the cap actually breaks tomorrow. If it doesn't we'll be sweating it out in the sun as we watch cumulus cloud towers fail to rise high enough for storms. Tomorrow morning I'll post again with an update on this potential.

Follow me on Twitter and Facebook for updates!

5/24 - 12:35am CDT - We're in... Iowa?

We didn't think we'd be in Iowa tonight. The storms that formed yesterday (Wednesday) rushed eastward as the cold front in the region decided to push further east than expected. Unfortunately none of these storms really did much because they formed in a linear fashion and didn't have the moisture necessary to get too severe. One of the southern cells in the line just west of Omaha, Nebraska managed to be isolated for a while and generated a wall cloud that triggered a tornado warning. Our only option in this environment was to cross the Missouri River in Omaha and wait for the storms to come to us because it would not be good to have the storms outrun us while trying to find a way across the river. The storms slowed down and died out pretty much at that point so we threw in the towel for the day.

Tomorrow will likely be a travel day back to Kansas or Southern Nebraska as we await Friday's potential chase setup. Storms tomorrow will be up near the Great Lakes in Wisconsin and Michigan and we just don't chase there due to the distance from the Plains and lack of good chase environment up there. Strong capping should keep storms from going up in the central and southern Plains, but we'll keep an eye on that in case that changes. Friday's setup may be decent if capping aloft doesn't ruin it. A deepening trough out in California and hopefully some better moisture return from the Gulf of Mexico should create potential for severe weather. A strengthening low in Southeast Colorado/Southwest Kansas should provide ample surface wind support for rotating storms should this pan out as forecast. The Storm Prediction Center already has a 5% risk area for this in their 3-day severe weather outlook. I'm crossing my fingers that this setup will yield some good storms because Friday is my last day chasing in the Plains until late June!

Follow me on Twitter and Facebook for updates this week.

Wednesday, May 23, 2012

5/23 - 11:50am CDT - Nebraska or Colorado?

Today we're in the Cornhusker state of Nebraska in search of severe storms. Yesterday's chase in what ended up being extreme southern South Dakota was short-lived as storms that formed up that way south of Murdo, SD quickly dissipated due to a low amount of moisture and contamination of their inflow via a layer of clouds that formed to the south of them. The storm we chased had a nice structure for a few minutes and even put down a bit of a wall cloud before it fell apart.

A cold front situated across the center of Nebraska will be the focus for storms this afternoon. The band of clouds on the satellite image is roughly where the front is located right now and it will slowly sag south and east today. A low forming over Eastern Colorado/Western Kansas should help back the winds out of the east this afternoon here in portions of Nebraska and that will increase low-level wind shear needed for rotating storms as that happens. This low will also create easterly winds in Northeast Colorado, so that may be a secondary target area for today.

We're already seeing some easterly winds beginning to set up in Nebraska this morning and we'll be watching where those develop this afternoon as well. Dew points are still quite low this morning in the upper 50's, but more moisture should move in this afternoon and bump up dew points to around 60 or higher. This is still a bit low for good storms, but we'll probably be better off than we were yesterday in this regard. Dew points in Northeast Colorado won't have to be as high for good storms thanks to the elevation there.

The environment today is rather "capped" as we say, meaning there's a warm layer of air above the surface layer that's prohibiting storm development. As surface heating gets going later this afternoon and into this evening there should be enough energy for updrafts to break through this cap and form storms. This means that storms should be fairly isolated at least starting out, which is a good thing since isolated storms are more organized, more likely to produce a tornado, and easier to chase. Some of these isolated storms may become supercells, and that's exactly the thing we're after since they may produce a few tornadoes today. Storms may condense into one or more lines of storms later this evening as the cap quickly erodes after dark. The Storm Prediction Center has a Slight Risk for severe weather today from Colorado to Minnesota and that includes a couple areas of 5% tornado risk. There's a chance we may bug out on our plans for Nebraska and move to the secondary area you see there in Northeast Colorado, so stay tuned.

Follow up-to-the-minute updates today on my Twitter and Facebook accounts!

Tuesday, May 22, 2012

5/22 - 9:45am MDT - Nebraska Here We Come!

Today's storm setup is tricky because we're dealing with, again, a situation where the moisture is not returning to the region as well as we need it to. The good news though is that the trough that is slowly making it's way eastward will finally be in play today, so upper-level wind support will be there for storms. Let's start with the moisture though. The higher dew points will be in the Dakotas today no doubt, but this is at the surface. With such a short time between being dry and having moisture moving into that region, this moist layer is likely very shallow and confined near the surface even though the short-range models this morning show it a little deeper than before (models have not been handling moisture well at all lately). This means that storms up that way would likely be low-precipitation supercells, maybe to the point where some of them are only putting down virga and not ground-falling rain. The better surface wind support near the low will also be in the Dakotas, but you won't get many, if any, tornadoes if the storms can't get any "meat" on them from the lack of moisture. Dew points in Northern Nebraska may be lower at surface, but we may have an overall deeper layer of moisture there.

The upper-level winds as I said before will be more favorable today than yesterday. The trough moving in will provide fast southwesterly winds in the Dakotas extending down to Northern Nebraska. This should bring in some drier air aloft and enhance wind shear for this afternoon's storms. Today we'll stay on the southern end of these winds aloft so that maybe we can get some deeper moisture coupled with the winds. Hopefully some supercell storms can form in this environment.

Because the models are having difficulties resolving moisture issues, today's CAPE (instability) forecast looks rather low in Nebraska with higher values north. This is something we'll be watching throughout the afternoon to see where it actually sets up. The potential lack of moisture and the best shear being removed from deep layer moisture will likely limit tornado potential today, but maybe we can see some high-based photogenic storms!

The Storm Prediction Center has a Slight Risk for severe storms today in the Dakotas extending toward Northern Nebraska. There's only a 2% tornado risk with this and I think this is a good call given the moisture issues here. If dew points were to be higher over a deeper layer in North Dakota I think you could have a pretty decent tornado risk from supercells given the forecast wind environment. In any case, our more southerly target today will put us in great position for tomorrow's chase, which will likely be in Nebraska.

Follow me on Twitter and Facebook for updates today!

5/21 - 11:55pm MDT - Nice LP Supercell Today

Today didn't turn out to be the best chase, but we made the best of it with the sighting of a nice low-precipitation (LP) supercell near Grande, New Mexico. This formed within a line of discrete storm cells that stretched from Southeast Colorado to Central New Mexico. The formation of these cells in a line among an environment characterized by northwest wind flow at 18,000 feet (500 mb) didn't make for the best conditions for severe storms, but a few of them did reach severe limits. Besides this low-profile supercell and possibly a couple others in the same line, an "out of the blue" classic supercell formed ahead of an eastward-advancing MCS (mesoscale convective system - line of storms) just west of Amarillo before being ingested by the actual MCS. It didn't form in the expected environment for this, so we were not in position to see this short-lived storm. More photos of the LP supercell we saw today are available on my Flickr and Facebook albums.

Our tentative plan for tomorrow is to head to the Valentine, Nebraska area to intercept a severe weather threat that may manifest up there as a large-scale trough begins affecting the Northern Plains. Many would consider this an "secondary" target area since higher dew points and better surface winds will be in North Dakota, but in this case the moisture up in North Dakota will likely be confined to an area closer to the surface since there will not be enough time for ample deep moisture to make it up that far north. Northern Nebraska should have some deeper moisture than North Dakota and even though less helicity (spinning motion in atmosphere) will be present in Nebraska, Energy Helicity Index values are still forecast to be elevated according to the Rapid Refresh model. We'll make a final determination based on data coming in tomorrow morning before heading out!

Follow me on Twitter and Facebook for updates on our chase!

Sunday, May 20, 2012

5/20 - 11:45am CDT - Texas Panhandle Today

We're on the road from Oklahoma City to the Panhandle region of Texas where storms are likely to form today. Right now we're watching a clear area on satellite near a cold front situated just south of a line from Childress to Lubbock, TX. This clearing should help to build instability for storms to form as heating from the sun is allowed to reach the surface. Winds and dew points at the moment are not terribly favorable, but the most recent RAP (Rapid Refresh) model does have surface winds turning more easterly during the afternoon bringing in more moisture.

Even though winds at the surface will likely be favorable, winds aloft at 18,000 feet (500 mb) will be weak and westerly to west-northwesterly. It would be preferrable to have winds at that level that are fast and from the southwest, so not having much of either of those components will be a limiting factor. Storms that form this afternoon could have some large hail and winds, but the tornado threat at the moment looks marginal given the lack of upper wind support and possibly lower dew points.

Given these factors, the Storm Prediction Center has decided to forgo issuing a severe weather risk for the area today and only has a general storm risk with mention of some isolated instances of severe storms. The trick today will be to find these isolated instances wherever the best environment for these sets up this afternoon.

The latest updates on our chase are available on Twitter and Facebook.

Saturday, May 19, 2012

5/19 - 11:30pm CDT - New Tour Group, Chase Tomorrow

This morning Tour 2's guests departed and this evening we just finished up orientation and dinner with the guests on Tour 3. This past week we went 2,402 miles (3,866 kilometers) across Oklahoma, Texas, Colorado, and Kansas. Everybody had a great time as we traveled from the Mexican border near Big Bend National Park in Texas all the way to Denver even though storms may not have been available to chase every day.

A rash of tornadoes southwest of Wichita, Kansas near Harper has us a little down this evening since they happened during our day to switch up tour groups in Oklahoma City. Unfortunately there was damage reported with these tornadoes, which seemed to be all rope-like based on the photos being posted via social media. The rope structure of these makes sense given the low moisture in the area which means that cloud bases were high. For tomorrow the setup does not look as favorable for tornadoes given the still marginal amount of moisture in the region and weaker upper-level winds, but our sights are set on Western Oklahoma and the Panhandle region of Texas as the cold front that triggered today's madness continues southward.

The Storm Prediction Center has a general thunderstorm risk with a 5% severe probability for the area in question tomorrow. They're not real optimistic about severe storms based on the weak upper-level and surface winds, but we'll see how that develops tomorrow. The one thing we have going is that the direction of the winds at the surface (mostly easterly) will contrast well with the mostly westerly winds at 500 mb (18,000 ft) for some directional wind shear. Good storms may be hard to come by on Monday, but as the trough that I mentioned in the previous blog post begins to move in I think our prospects will improve during the week.

Follow me on Twitter and Facebook for the latest on our chase!

Friday, May 18, 2012

5/18 - 2:45pm CDT - Regarding Next Week's Chase

As we make our way back to Oklahoma City on our last day of this week's storm chasing tour, I'm looking over quite a bit of data for next week's severe weather potential. After a lengthy period of high pressure ridging across the Plains (A.K.A. no storms) we're finally seeing signs that a large-scale trough will begin to move onshore from the Pacific and begin to affect the Plains during the middle part of the week. A smaller trough will be coming through this weekend as well but not a lot of moisture and our inability to chase during its peak on Saturday due to our down day in Oklahoma City means it will not be discussed here.

This trough coming in next week will need some moisture to work with for severe weather to form. This is something we've had a problem with for a while now but it looks like the Gulf of Mexico will finally be "open for business" starting next week. As the trough begins creating southwesterly winds and diffluence aloft in Kansas extending into Northwest Oklahoma on Wednesday (5/23), southerly winds at the surface should begin to bring in some much-needed moisture. The degree to which this will happen is still very much up in the air at this point because the GFS model has been consistently overshooting actual dew points, meaning it's been too optimistic about moisture return. The European model does agree that moisture will begin flowing into the Plains on Wednesday, but to a lesser degree than the GFS on the right.

This setup will continue right into Thursday and Friday as the trough digs in and moisture continues to flow into the region. These two days may harbor better severe weather chances than Wednesday due to having more time for moisture to return. Given the possibility that small-scale weather phenomena like cloud shields and overnight storms could limit potential on any of these days it's very difficult to point out which of them will be the best for storm chasing. Not only that, but the aforementioned computer model issues and amount of time between now and the trough moving into the Plains creates an even bigger margin of error. It's safe to say right now that things are certainly looking more favorable synoptically (on a large scale) for severe storms, but calling for a tornado "outbreak" at this point wouldn't be logical due to the variability of all the smaller features involved. This setup certainly has our attention and we're keeping close watch! Our robotic streaming webcam has been sitting dormant since we haven't had any storms lately, but we're hoping that we can put it in action next week.

Follow my storm chasing updates on Twitter and Facebook!

Thursday, May 17, 2012

5/17 - 4:15pm MDT - Some Fun in Denver!

Since good storms for chasing didn't form yesterday and won't form today, we're having a bit of fun in Denver, Colorado! Today we split into a few groups, one group that toured the Front Range of the Rockies, one that went to the Denver Art Museum, and another that went to the Elitch Gardens theme park in town. We all had a great time and will meet up this evening for dinner. Tomorrow we'll be heading back to Oklahoma City as Tour 2 ends and we'll be saying goodbye to our guests on Saturday morning.

For next week's tour, Tour 3, there may be a return of severe weather to the Plains. This may take until midweek though as a large-scale trough moves inland from the Pacific and moisture flows back into the region near the surface from the Gulf of Mexico. A lack of moisture in the Plains has plagued us for days now, so this return will be very welcome if what the long-range GFS model indicates pans out.

Be sure to keep up with my updates on Twitter and Facebook!
 

Wednesday, May 16, 2012

5/16 - 10:45am CDT - To Colorado We Go!

After spending quite a bit of time in Texas over the past few days we are on our way north to Colorado this morning. We're going to try to chase some storms that may form in the upslope flow of the Front Range of the Rockies. Here's how these form: Moist air flows from east to west up the gentle slope of the mountains during the afternoon. This moist air when lifted by the terrain condenses because it's moving into cooler air aloft. As more air rises up this gentle east-west slope, it continues to condense to form clouds and eventually thunderstorms. Since the mountains act as a constant source of lift, these storms can be pretty reliable as long as other ingredients are in place.

Here's the issue for today though... Moisture is going to be hard to come by today because the last major system to roll through the Plains last week pushed all the moisture down toward the Gulf of Mexico. A little bit of it will be returning to the region today though and we can already see that happening on the current surface map. Dew points right now are in the 30's with a couple 40 degree plus readings across the eastern part of Colorado where these storms will form. In a perfect world you'd want easterly winds to be blowing in better moisture and to create better low-level shear, but this morning we're dealing with southeasterly winds. The good part is that it doesn't take as much moisture to generate these storms as it does in lower elevations. Generally you want dew points to be above 40 degrees in this region, and that's something we may struggle to get today if the computer models are correct.

Putting all of this together with some weak southwest winds at 500 mb (18,000 ft) there is a chance for some storms in Eastern Colorado today. With potentially weak moisture return the setup for anything severe looks very "iffy" at this point and the Storm Prediction Center has placed parts of Eastern Colorado under only a general thunderstorm risk because of this. We'll keep an eye on the surface observations this morning and afternoon to determine whether moisture will return as needed.

Last night I had a good internet connection at our hotel and was able to upload some video. Check out my footage of our encounter with golf ball size hail and flash flooding east of Lajitas, Texas on Monday:




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Monday, May 14, 2012

5/14 - 12:45pm CDT - Pressing Further Southwest in Texas

Today we're continuing on southwestward in Texas where fast westerly and northwesterly winds aloft and moist, easterly winds at the surface will combine to create a potential for severe weather. These winds should create enough shear for supercells among some scattered storms and more specifically there is a chance for a couple tornadoes down this way. There are a few clouds on the visible satellite view right now from ongoing storms in the region, but areas closer to the Mexican border near Marfa and Fort Davis are pretty much cloud free. There is a field of cumulus clouds we're driving toward south of Marfa that may serve as a focus for development, so we'll see how that pans out. In any case we have lots of direct sunlight and instability already building for storms later this afternoon.

The Storm Prediction Center has issued a Slight Risk for severe weather today across extreme southwest Texas where we're at and they've even included a 5% tornado risk area. This is the best setup we've had so far this week, so we remain hopeful that we'll see some great stuff today! There aren't many roads around the area so this will be a challenging chase day even though the ingredients appear to be coming together pretty well.




Follow me on Twitter and Facebook for the latest today!

Sunday, May 13, 2012

5/13 - 10:15am CDT - Going West!

This week's storm chasing tour is starting out with a trip west from Oklahoma City. Fast westerly and north westerly winds aloft this afternoon over West Texas and Eastern New Mexico will provide support for potentially severe storms. While originally it looked like we would definitely be chasing in an area near and west of Fort Stockton, TX, the latest data coming in right now has actually increased the amont of moisture closer to Amarillo and Lubbock, TX. This moisture along with easterly winds rotating around a high pressure center near Wichita, KS could provide a secondary target area for us, which is good because we may not have to drive as far today! We're keeping an eye on the trends as we're traveling west on I-40 and right now we're leaning toward the more northern target near Amarillo and Lubbock because we think the models are underestimating the amount of moisture that will be allowed into that region this afternoon.

The satellite picture has been on our computer screens this morning too because it's revealing where storms may set up later on today. The previously more favorable target near Fort Stockton in far West Texas on I-10 looks a bit dismal at the moment because of the showers and clouds currently over that area. This may act to inhibit surface heating and the building of instability this afternoon for storm development. There are some storms in Eastern New Mexico, but those may actually help to moisten up the atmosphere closer to where you see the favorable clear slot in the clouds near Amarillo and Lubbock.

The Storm Prediction Center has a Slight Risk area for severe weather over extreme West Texas and the eastern half of New Mexico for this afternoon. This outlook came out before the latest data showing the favorability in conditions near Amarillo and Lubbock did, so some northward changes may be made in the outlook that will come out at 11:30am CDT. Overall, the (small) tornado threat today highly depends on how much moisture we can get into the area so that cloud bases are low enough along with how much low-level shear sets up.

Follow me on Twitter and Facebook today for live updates!

Monday, May 7, 2012

5/7 - 10am CDT - On Our Way to South Texas

The same cold front that we targeted yesterday in Kansas and Oklahoma is on the move southward and so are we. We're on our way to South Texas this morning to meet up with where the front, the dry line (boundary between moist air to the east and dry air to the west), surface heating, easterly winds, and moisture all meet up. Storms should fire along the front and/or dry line this afternoon as instability builds. You'll see in the image to the right that there's a sliver of high dew points that will develop in Southwest Texas this afternoon that will be our focus as the cold front moves south.

Due to the threat of severe storms this afternoon, the Storm Prediction Center has issued a Slight Risk area for portions of South Texas with a 2% tornado risk (pictured left). Some of these storms will have large hail and damaging winds. The tornado risk, like yesterday, looks fairly low due to weak winds aloft, but the directional wind shear will help out as well as high instability. There may just be enough ingredients to spawn one or two tornadoes today down there, so we'll cross our fingers and keep driving!

As usual, I'll be posting up-to-the-minute storm chasing updates on my Twitter and Facebook accounts today.