Dangerous situation unfolding across Kansas, Oklahoma, and northern Texas

HIGH RISK OF SEVERE WEATHER FROM SOUTHERN KANSAS, THROUGH OKLAHOMA, AND INTO NORTHERN TEXAS. SEVERAL STRONG, LONG TRACKED TORNADOES POSSIBLE TODAY, ALONG WITH VERY LARGE HAIL AND DAMAGING WINDS.

15z surface analysis shows a low pressure system in the panhandle of Oklahoma, with a stationary front extending northeast across central Kansas, through Iowa and into northern Illinois. A cold front is extending down from the low, and bending around through the panhandle of Texas. A dryline extends south of the low, out in front of the cold front, and will be the focus of today's storms.



The combination of surface heating, high dewpoints, and strong wind shear will lead to an outbreak of supercells capable of producing very large hail, damaging winds, and several large tracked tornadoes, with the area within the high risk the most likely to see these tornadoes. Below are the list of risks, issued by the SPC at 1630z.

RISK

TORNADO RISK

HAIL RISK

WIND RISK

Here's a peak at the first tornado watch of the day, covering the higher risk area for today, with the probability of seeing several strong tornadoes being quite high.



Taking a look at current meso analysis shows significant tornado probabilities climbing quite high, and are expected to continue to increase as the day wears on. 0-6km bulk shear is also climbing rapidly across western Oklahoma, and will continue to move east, and increase as the low level jet strengthens later this afternoon. SPC is forecasting explosive development of cells, with very large hail being the initial threat. As that LLJ continues to strengthen, the tornadic threat will also increase.

Enhanced Tornado Index

0-6 Shear

850mb GFS forecast

People across these risk areas need to pay attention to the changing weather conditions, as several more watches will likely be issued as the day wears on. Any cell that forms will become supercellular rapidly, and has the potential to become tornadic.

Severe weather outbreak possible across parts of the south

POTENTIALLY DANGEROUS SITUATION EVOLVING ACROSS OKLAHOMA AND KANSAS.

Today's greatest focus for severe weather will be from south central Kansas into parts of central and eastern Oklahoma, per the SPC's 06z outlook, which is shown below.



The 06z surface analysis across the south shows a low pressure system in southeast Colorado with a cold front extending down through the Oklahoma and Texas panhandles, and a warm front stretched through central Kansas. A very potent dryline also extends down in front of the cold front into Texas, and will be the focus of today's severe weather. Note on the analysis map below the extreme difference in dewpoints, pre (dewpoints in the upper 60's) and post (dewpoints in the teens and low 20's) dryline.



As the day goes on, the low pressure system will deepen and move slowly to the northeast across central Kansas, while swinging dryline across southern Kansas, Oklahoma, and Texas. 24/00z GFS 30mb dewpoints (see below) clearly show the contrast in dewpoints, and the focal point for thunderstorm development. By 7pm CDT, the low pressure area should be in west central Kansas, with a warm front extending from central Kansas, and off to the northeast across northern Missouri, with the cold front bending back into the Texas panhandle, and dryline extending south of the low through southern Kansas, Oklahoma, and Texas, also seen in the image below.





GFS's 500mb 18z forecast map (see image below) shows a negatively tilted trough with two vort maxes moving with the trough. These vort maxes will assist in the triggering of severe thunderstorms throughout the afternoon and evening hours.



GFS's 700mb 18z forecast map (see image below) shows moderate wind speeds of around 25 knots in the area of concern, increasing to 35-45 knots as the day goes on. These winds are expected to generally be out of the south/southwest. These winds, combined with winds out the southeast at the surface, should provide enough turning in the atmosphere to create supercells capable of dropping large hail, and potentially long tracked tornadoes. The SPC (also posted below) has, therefore, issued a 30% risk for tornadoes, with a hatched risk showing the potential for significant (greater than EF-2) tornadoes.





A quick peek at the GFS's 850mb 18z forecast map shows weak to moderate winds, in the range of 20-30 knots across northern TX, eastern Oklahoma, and southern Kansas, but increasing to 35 to 45 knots by 25/00z. (See images below) These winds will be out of the south, which will help to draw up a significant amount of moisture (see 30mb dewpoint map above) This moisture will add a lot of fuel to the fire, and will also lead to some serious flooding concerns, as these storms will be going over areas that have already been hit hard by severe weather over the past few days.

18z forecast map

00z forecast map

Something else to note is the amount of CAPE (convective available potential energy) this system will have to work with. By 00z Wed, the GFS is showing an band of MLCAPE between 3500 and 4000 J/kg, with CINH (Convective Inhibition) rapidly erroding. These high CAPE numbers, along with little CINH will allow for rapid, explosive development of supercells, and fairly low freezing levels will allow for very large hail to develop. The SPC has highlighted this threat as well with a 45% risk for hail, and have hatched that risk to signify the potential for significant hail.

CAPE

CINH



As the evening and night wears on, the SPC is forecasting for the cells across Texas and along the dryline to begin to diminish as capping takes over, however a continued wind threat may be seen as storms further north continue to press off to the east. SPC has a 30% risk for wind highlighted to cover the initial wind threat, and lessening the threat as it moves east. (See graphic below)



People need to be aware of what is going on through the day if they live in these higher threat areas. It has already been a very active year across the south, and is proof that these storms, even with all the current technology, can be deadly if a person isn't prepared. Keep those NOAA weather radios on, and make sure they have good batteries in them.

The winter that won't go away

This winter was predicted to be a long, snowy winter, and to this point it certainly has lived up to its hype. Almost 70 inches of snow here in Eau Claire with places in Minnesota approaching the 90 inch mark. Most of the snow had melted a couple weeks ago, before another system came in, dropping anywhere between 6 and 12 inches of new snow, and pretty much gave us back what we had melted. Again, we warmed up, and again this snow melted, and again a potent storm system came through and dropped 6-12 more inches of snow across parts of central Minnesota and western Wisconsin. As this snow pack had melted, the moisture from the snow eventually ran into the rivers, and put some rivers and streams over their banks. Potential record flooding is possible along several points of the Minnesota and Red River Valleys during this spring, and it doesn't look like we will be seeing a long enough stretch of dry weather to cut down on the flooding potential.

This week, fortunately, is looking somewhat quiet, with just a few precip chances for the end week. At this point, it doesn't appear to be anything significant. Surface temps should be well above freezing during the day with temps dropping a bit below freezing overnight Thursday into Friday. Saturday looks like a nice day with temps in the upper 40's to near 50. Sunday into early next week continues to be the time to monitor, as a low pressure system passes south of the area, and a fetch from the Gulf. Showers and thunderstorms could break out across southern MN and western WI during this time, with the potential for half inch or more of rain. This system is a ways out, so plenty can change between now and then. Models haven't really locked a solution yet, so there is little certainty on what will potentially happen. The central plains and parts of the south will need to monitor this as well, as severe weather could be possible from Missouri on south through Texas on Sunday afternoon/evening. Pretty strong cap may be in place, but again this is a ways out so lots can change. Something else to note is some of longer range forecasting tools are hinting at the potential for another shot of below normal temps as we get further into April. I'm really hoping this changes, and we could get into some warmer temps to get rid of the remaining snow, and push us into summer and thunderstorm season. Until then, we'll have to deal with this roller coaster that we in Wisconsin (or Minnesota) call spring.

2010: A Year in Review

Anyone who says that Minnesota or Wisconsin are boring must not have been living here in 2010. After what was a somewhat slow start to the year, things picked up dramatically and really haven't let up since late spring. To mark the end of the year, I decided to take a look back at the year, and rank what I think are the top 5 weather events of the year. I first thought of doing a top 10, but really a top 5 I think is more reasonable. So without further delay, my top 5.


Number 5 - Snowless March

While the other top events of 2010 will consist of weather actually occurring, this one was chosen due to the lack of weather. For the first time since weather data has been recorded, no measurable snow was recorded at the MSP airport, or at Eau Claire's airport. While some may not think this is much of a surprise due to it being March, and almost spring, it actually is a surprise because March is typically one of, if not the snowiest months that we see. This rare event, however, did help reduce the amount of flooding that is typically seen every year due to the snow melt into the Wisconsin and Minnesota rivers.

Number 4 - Record Low Pressure/Windstorm




On October 26, 2010, a low pressure system, with a cold front attached moved across the northern United States, while a secondary low moved up from the south and merged into one "megalow". The low moving from the south ended up becoming the main low, and rapidly deepened (or strengthened) bringing some incredibly strong winds along with it. The main low bottomed out around 28.20 inches of mercury (954.96mb) at Bigfork in Itasca County. This shatters the old Minnesota lowest pressure record of 28.43 that was set in the November 10, 1998 storm at both Austin and Albert Lea. The state of Wisconsin also broke their state record for pressure, with Superior recording a reading of 28.39 inches of mercury (961.3mb). That broke a record that stood for more than 28 years, dating back to April 3rd, 1982. The measurement was taken in Green Bay. The storm brought sustained winds between 20 and 30mph, with gusts of 40-60+mph. This caused power outages, trees to fall, and people's lawn furniture to end up in their neighbors yard. This low was also able to tap into some moisture from the south, and cold air from the north, creating the first decent snowfall across Minnesota and North Dakota. Blizzard warnings, High Wind warnings, and a whole slew of other advisories cover the area. The cold front extending from the low ended up causing problems across a good portion of the central and eastern United States.

Number 3 - Southern Minnesota/Western Wisconsin flooding

Beginning the afternoon/evening of September 22nd, a moist airmass moved into the area, and a slow moving warm front moved into southern Minnesota before stalling out to a stationary front. The combination of these two things created a long duration heavy rain event which ended up causing rivers to overflow, and farm fields to turn into lakes. The rain didn't stop falling until late in the day on September 23rd, but its effects were felt days, even weeks later. Below is a graphic of rain totals that were observed across southern Minnesota and western/southern Wisconsin, courtesy the National Weather Service in La Crosse, WI.



All of this rain, along with its eventual runoff, caused flooding for a couple weeks after the rain had ended. Fortunately, this rain was followed by a dry stretch that lasted nearly a month. This allowed the rivers to eventually fall below flood stage, fields to dry out, and farmers to make good progress on their annual harvest.

Number 2 - June tornadoes/record season

There was much thought put into whether or not to put this at number 1 or 2, and in reality, it could easily be put in the number 1 spot. But after all that thinking, the record year Minnesota had takes the number 2 spot. While the season as a whole was quite remarkable, one day in June covers a good chunk of the overall tornadoes that Minnesota saw through the year. A warm and extremely unstable airmass moved into Minnesota during the day of June 17th, 2010, setting up what would be the largest outbreak of tornadoes Minnesota would see during a 24 hour period. Three fatalities (2 from northwest Minnesota, and 1 from south central MN), as well as many injuries were reported as a result of the outbreak. 48 of Minnesota's record breaking 105 tornadoes were reported on the 17th of June. Although a majority of the tornadoes were rated EF-2 or lower, four of them received EF-3 ratings, and three of them received EF-4 ratings. Below is a storm reports map from the 17th.



Also, here is a link which contains info of each tornado for Minnesota. http://www.crh.noaa.gov/images/mpx/2010torlist.pdf

Number 1 - Blizzard of 2010

This years number one event actually happened closer to the end of the year. On December 11th, 2010, a large, slow moving area of low pressure moved across central IA and northern IL, strengthening and tapping into Gulf moisture as it trekked east. North of the low, a wide swath of snow formed, dropping snow at rates of 1+ inches/hour. Wind speeds increased as the low strengthened, creating whiteout conditions and making travel impossible. Many roads were considered impassible, and access to the I-94 was restricted across western Wisconsin due to those whiteout conditions, and large snow drifts that were forming on the road. What makes this storm such an impressive system is the fact that such a large area saw well over a foot of snow, and even those areas that initially saw a little mixing of freezing rain and sleet still saw 10+ inches of snow. Below is the snowfall map from that storm, over a 24 hour time frame, courtesy of the National Weather Service.



Although there were a lot of high totals of snow, some notable ones were from Osceola, WI with 23 inches of snow, Eau Claire, WI with 22 inches, and even the Twin Cities with 17 inches. In fact at the Metrodome in Minneapolis, the snow was so much that it caused the roof of the dome to collapse, forcing a game between the Vikings and the Giants to be moved to Detroit while repairs were done. Schools in Minnesota were closed for several days after because the snow removal process was slow going, and rightfully so. That storm, as well as several others in the Twin Cities, led to a record breaking December for snow totals on record. Here in Eau Claire, we are second snowiest on record at this point, but are less than 2 inches away from surpassing the top mark for the month of December. With at least 3 months of potential snow accumulating days it will be interesting to see how much actually falls over the winter, and how much of an impact it will have on the annual spring floods that we see. 2010 will be tough to beat when it comes to significant weather, but 2011 may be full of a few new surprises. You never know :)

Quite pattern, but trending colder

After an exciting week last week and the record breaking low (falling just short of breaking the U.S. lower 48 record for a non tropical system), we have fallen back into a quiet weather pattern. That quiet pattern will hold, at least for a little while longer. In the mean time, a shot of cold air looks to work its way down from Canada, covering a good chunk of the eastern U.S. This could spell trouble for the east coast as this trough digs south and interacts with a system working up the coast. Heavy rain and mountain snows appear likely with this system, but the models are having a difficult time coming to a common solution on the strength of that system. For around here, the week will start out decent, but a cold front coming through Tuesday/Wednesday will cool temps down to the 40's to end the week. Temps should moderate some to end next weekend as the ridge out to our west begins to work east. Could see some light precip forming along with the frontal passage, and maybe a little light mix on Thursday, but other than that, things will be quiet.

Just taking a peak into the longer range, the GFS has been hinting at a pretty good shot of cold air coming down. Riding along that edge of colder air could be a decent storm system, and potentially the first widespread snowstorm for somewhere close to home. It's a ways out, and plenty can change between now and then, but the GFS hasn't lost it yet, and even the ECMWF is hinting at something getting spun up. It is something to monitor, but keep in mind that most models really tend to struggle during the transition of the seasons. Forecasters have been calling for a snowy winter, so we'll see if things will get going in the next 10 or so days.

Record setting day across the Midwest

After what has been a slow, dull, boring (but actually kind of nice) October, mother nature quickly reminded us where we all live, and how quickly things can change. A low pressure system, with a cold front attached moved across the northern United States, while a secondary low moved up from the south and merged into one "megalow". The low moving from the south ended up becoming the main low, and rapidly deepened (or strengthened) bringing some incredibly strong winds along with it. The main low bottomed out around 28.20 inches of mercury (954.96mb) at Bigfork in Itasca County. This shatters the old Minnesota lowest pressure record of 28.43 that was set in the November 10, 1998 storm at both Austin and Albert Lea. The state of Wisconsin also broke their state record for pressure, with Superior recording a reading of 28.39 inches of mercury (961.3mb). That broke a record that stood for more than 28 years, dating back to April 3rd, 1982. The measurement was taken in Green Bay. Below is a graphic showing the progression of the low, courtesy of the NWS Office in La Crosse.




With this, the storm brought sustained winds between 20 and 30mph, with gusts of 40-60+mph. This caused power outages, trees to fall, and people's lawn furniture to end up in their neighbors yard. This low was also able to tap into some moisture from the south, and cold air from the north, creating the first decent snowfall across Minnesota and North Dakota. Blizzard warnings, High Wind warnings, and a whole slew of other advisories cover the area. The cold front extending from the low ended up causing problems across a good portion of the central and eastern United States. Severe storms containing damaging winds and tornadoes caused damage across parts of southern Wisconsin, Tennessee, Indiana, Ohio, Michigan, as well as a few other states. This is a link to a more detailed description of what happened, courtesy of the Minnesota State Climatology Office http://climate.umn.edu/doc/journal/low_pressure_101026.htm Below is a satellite image of the low, with the cold front extending south off of it.

Yawn....

Well, what a stretch of weather we have had here in Western Wisconsin. It has been at least 15 consecutive days of dry weather, and that trend looks to last another 4 days at least. This dry stretch, however, was needed after the flooding rains most areas received about a month or so ago. Farmers have been taking advantage of this stretch of dry, warm weather by getting their harvesting done before we see any more rain, or even snow. Yes, that dreaded "S" word will be being used more and more in the coming months, but it shouldn't be seen for a little while yet. However, what is good for some, can be bad for others. While the farmers and most of the general public has been enjoying this stretch of dry weather, it is now to the point that the things leaves and grass are getting too dry, leading to a high fire risk across most of the area. So, quite frankly, some rain wouldn't be the worst thing in the world right now. It does, however, look like we will have to wait until next week before any chance at some measurable rain reaches the area. First things first...

Today looks to be mostly sunny, with maybe a few clouds here and there, highs right around 58 degrees. Tuesday night, a few clouds, temps dropping to around 38 degrees. Wednesday will be breezy in advance of a cold front that will be coming through. Temps will be slightly warmer with highs getting to around 60 degrees.

Looking further down the road, a change will begin taking place over a good portion of the United States, however how that change will unfold is still uncertain. A potent system will be coming onshore over the Pacific northwest this coming weekend, bringing with it a much more active pattern, with some long range models spinning up some decent storm systems that could hit the area with rain, wind, and colder temperatures. In fact, looking wayyy down the road, the GFS is hinting at the potential for some accumulating snow a couple days before Halloween. Keep in mind that this is far in the model, and will likely change as time goes on, but there has been a trend that at least one decent system (likely rain) will hit the Upper Midwest sometime next week. Below is a look at the system, per the GFS, the morning of October 29th. Again, it is a ways away, but when you're bored, you grasp for anything.



I will continue watching next week to see how next week unfolds. Until then, enjoy this (likely) final stretch of nice weather, because this could honestly be it until next spring.