Severe Weather Potential - August 7 Update #3

Despite the hopes for convection before sunset, it does not appear likely as sunset is within an hour or two and there is not even a watch issued for potential development. Some cumulus is occurring in the warm sector, however, temperatures at 700hPa have increased to 14C directly over the most likely area for development. This is suppressing any chance of convection until at least after sundown across the area...

Thunderstorm development is still possible along the front as the low level jet increases slightly and we see the decoupling of the boundary layer. The tornadic threat with this development will be fairly minimal, with a large hail threat, and a more likely damaging wind threat across portions of southeast South Dakota and then across northern Iowa and southern Minnesota. An additional update is possible, but only if development can actually occur.

Once again Iowa has went and gone off to disappoint the severe weather lovers across the northern plains!

Severe Weather Potential - August 7 Update #2

Convective inhibition remains strong, however, confidence has increased that the inhibition will yield to convection during the late afternoon or evening hours across portions of the warm front in South Dakota and Iowa. Thunderstorms that do develop are likely to be supercellular with the threat for very large hail, damaging winds, and tornadoes given good low level shear and strong instability.

Just a short update... Expect to leave for a chase target in vicinity of Storm Lake, IA in approximately an hour. Storm initiation by 7 PM along the warm front in vicinity of prolonged strong low level convergence that is occurring in this area. Storms should follow this warm front, tapping into strong instability and good shear parameters leading to a continued tornado threat through 9 PM. Eventual evolution to a cluster or linear segments is expected beyond 10 PM with more of a damaging wind threat.

Severe Weather Potential - August 7 Update #1

Not much for changes in the going forecast or in the current analysis of things across the plains states. Watching clearing skies across the Dakotas and Nebraska, which should also work into western Iowa during the early afternoon hours. Warm front currently located along and just east of the Missouri River from South Dakota into western Iowa. This front should slowly move a bit northward, currently inhibited due to cold pool left from cloud cover and showers this morning. Strong instability and good inhibition is still in the forecast for the warm sector through this evening. A shortwave currently over eastern Colorado should move over the corner regions of SD/NE/MN/IA during the evening hours and should provide enough support for the formation of isolated thunderstorms.

Thunderstorms forming along the warm front would appear to be supercellular in nature during the evening hours, with the threat of very large hail, damaging winds, and the potential for a tornado given favorable storm motion. Storms should merge in the early nighttime hours, and begin more of a damaging wind threat across northern Iowa and southern Minnesota. This is confirmed with the latest SPC outlook upgrading the probabilities for damaging winds across this region...

Will watch the warm front evolution, as well as the 700hPa temperatures that will be inhibiting development until the Colorado shortwave makes its' way over during the evening hours.

Severe Weather Threat - August 7

Morning convection continues across southwest Iowa, with additional showers/thunderstorms spread throughout the state and spreading eastward at approximately 30-40 mph. These thunderstorms and showers should continue through the morning hours across much of the state, with cloud cover also remaining through 10 AM across the entire state. Look for a gradual decrease in coverage in both showers and cloud cover through the Noon hour and into the afternoon. Skies should begin to clear from west to east through the Noon hour as well, beginning to leave portions of western Iowa under warm and sunny skies by early afternoon. A warm front currently positioned south of the thunderstorm activity this morning should make its' way northward as the lee cyclone moves out of eastern Colorado and into the plains this afternoon. The warm front should become positioned parallel to I90 across southern Minnesota and likely through South Dakota, with a very warm/moist and unstable air mass to its' south.

Instability values should become quite high (3000-4000 j/kg) given surface temperatures near/above 90 degrees and dew point values well into the 60s and perhaps 70s along/south of the warm front. Strong surface convergence as well as theta-e should be taking place along the warm front, with aid from a subtle disturbance in the mid-levels also arriving during the evening hours across northwest Iowa. The combination of strong instability and continued convergence along the boundary may have the potential to break a cap that is likely to be in place throughout the afternoon south of the warm front. Temperatures at 700hPa are likely to be in the 11-13C range, with temperatures at 850hPa above 20C. Despite the warm temperatures aloft, models continue to indicate surface heating is enough to overcome the cap in areas that have this strong convergence along the warm front.

If the cap is overcome within the warm sector across northwest Iowa or South Dakota, expect rapid intensification of updrafts leading to large hail becoming a likely threat. Given strong shear values, especially for the late evening and early nighttime hours as the low level jet begins to aid the low level flow, a tornadic potential will exist with any development. Expect storms to begin to form into somewhat of a cluster or MCS after 10 PM and continue across the state, with perhaps an additional MCS moving out of the Dakotas and into MN/IA during the nighttime hours. An additional update is likely near the Noon hour, and once again through the afternoon and convective inhibition and the location of boundaries, etc. becomes more defined.

Storm Chasing Status: With a conditional threat, I will likely be sitting in the comfortable confines of home through the afternoon. However, with the threat likely evolving within an hours drive will be watching conditions closely. Current four county target area is Lyon and Osceola counties in northwest Iowa, and Nobles and Rock counties in southwest Minnesota.

A Quick Recap

Busy days ongoing for me has created a good lack of updates on my part. Just to review back to July 14, the severe weather threat did materialize, although much weaker than initially thought due to only convection along the front firing during the evening hours. Did manage to punch through a severe warned cell between Wallingford and Ringsted on the way back from a playoff baseball game. This cell didn't really back much punch in regards to wind, and no hail was found. A weakly photogenic shelf cloud was noted, but not captured...

After the cold front passed through the state we were left with some below average temperatures that have continued into tonight. Current temperatures early this morning range from the mid 50s to the upper 40s! High temperatures for Friday should range from the upper 60s to the mid 70s across the state from northeast to southwest; lows overnight will drop into the upper 40s to mid 50s across the state once again. The weekend will stay dry with highs in the upper 60s to mid 70s from east to west on Saturday, then from mid 70s to mid 80s by Sunday. Low to mid 50s for Saturday night temperatures, and mid 50s to lower 60s from east to west for lows on Sunday night.

We'll return to chances of thunderstorms and showers for the work week, with the best chances on Monday night in the west; Tuesday and Tuesday night for the central and eastern thirds, and the potential for a lingering shower or storm in the east on Wednesday. High temperatures in the upper 70s to mid 80s from east to west for the first half of the work week; with lows in the upper 50s to mid 60s. Look for an update on these chances of thunderstorms come early next week!

Severe Weather Potential - July 14

The potential for a significant severe weather event over portions of the central/northern plains is there for tomorrow, as potent surface features will be supported by strong upper air parameters. Two areas of interest are going to come into play, both of which have some very big question as to its' potential to produce significant severe weather. A lot of the questions may be answered tomorrow morning once the evolution of the MCS(s) from current severe/tornadic convection across SD/NE is known. An update during the overnight hours or during the early morning will hopefully give an idea as to which area of concern is greatest.

The most favorable target will likely be along a reinforced warm front or outflow boundary following tonights' convection that will setup across southeast Nebraska, southwest Iowa and across northern/western Missouri. Strong heating and moisture return will be in place for this area, providing extreme instability and likely strong lift. Upper air features better align with this area of instability and lift, aided by a shortwave that would likely aid in development. As with the case with most late season events with such extreme parameters in place is the capping concerns... Temperatures at 700hPa near the 12C mark will likely cap thing well into the afternoon, however, there is support with the models indicating that this capping inversion will be broken before 00z. A target in this area could come with some significant rewards, or you could end up with nice blue skies as the cap holds.

Another target area will be further north along the cold front which is forecasted to move into western Minnesota and near the SD/NE/IA/MN corners and into eastern Nebraska. Capping will be less of a concern here with a strong mechanism for storm development (cold front) and 700hPa temperatures less than 12C. Development is likely by the evening hours along the cold front throughout western Minnesota and into SD/IA/NE. The problem with the setup here arises with the displacement of instability and shear parameters, with strong instability present along/ahead of the cold front (especially at low levels), but the best shear further ahead of the front. Any development just ahead of the cold front may be able to tap into both instability and shear, thus able to put on a show... This would rely on any outflow boundaries from morning convection...

Additional updates likely within the next 8-12 hours... I will likely favor the secondary target area as it is quite local.

Chase Account - July 9

Several rounds of severe weather swept across portions of northwest Iowa yesterday, from mid-afternoon hail to evening and overnight storms that left hail, winds, and heavy rainfall across parts of the state. I made a trip out to view the storms on two occasions yesterday, once during the mid-afternoon hours between 3:30 and 4:30 PM. This was the initial round of storms that produced some large hail from the SD/IA borders eastward to near Highway 71. Upon arrival to the storms, they were weakening significantly and led to only heavy rains that would obscure your view pretty good. On this trip we would also arrive upon an accident that occurred just west of Ruthven, IA where it appeared a vehicle may have been pulling out of a private lane onto the highway and did not see the cross traffic. A bad scene there as both vehicles were badly damaged, however, have not heard any news about this accident and how either drivers/passengers fared.

The second chase came during the waning daytime hours, from ~8:30 PM to after 10 PM across portions along the Dickinson/Clay county lines and back towards Wallingford in Emmet county. Several occasions of strong lightning strikes, and torrential/blinding rains with the multiple storm cells that we crossed paths with. On the backside of the last cell to be severe warned across these counties we were able to capture several occasions of 3/4" hail and strong east-southeast winds of 40+ mph. Video was captured from the dash cam for the entire trip, however, nothing significant to really note and share... A nice local chase/spot to add on for the year; now we'll wait for some true summer isolated cells to actually have some photogenic quality to the storms!

Severe Weather Potential - July 9

A complicated forecast is in the works for the next 36 hours, and perhaps even longer, for Iowa and adjacent areas. A strong wave will initiate thunderstorms this afternoon across the western Dakotas and areas of Montana/Wyoming. These storms should develop into a large MCS, possible derecho, during the evening and overnight hours traversing the Dakotas and moving into western Minnesota by sunrise on Thursday. This MCS will likely be making a right turn throughout the night as the low level jet veers, making the projected path perhaps into northern Iowa between 6-10 AM tomorrow. While the severe weather threat would seem minimal, gusty winds nearing severe criteria is a definite possibility.

As this MCS clears, a stable layer will be left over and likely inhibit additional development until the later afternoon hours. With a cold front and strong disturbance coordinate to create sufficient lift to break and inhibition that will be present across northern Iowa and southern Minnesota. With wind fields increasing in strength throughout the lower and mid-levels, expect deep layer shear to be sufficient for supercells as the initial storm mode with damaging winds, large hail, and isoalted tornadoes all being possible. However, with time and more forcing along the cold front it would appear that the growth of another MCS is likely, yielding a damaging wind threat across the central portions of the state. More details into the forecast will be clear tomorrow morning when the extent of the morning MCS is known... Expect an additional update late tonight and early tomorrow as to the possibilities of severe weather across portions of Iowa.

Severe Weather Recap - July 7

A cluster of thunderstorms developed in eastern South Dakota during the afternoon hours yesterday, and entered into northwest Iowa during the evening hours. These clusters of storms were at times severe warned with the potential for both damaging winds and large hail, estimated 60 mph winds were reported and hail up to 1.5" in diameter also occurred. The severe weather was intermittent at best, with little in the way of damage reported.

I ventured outside of home for a short while as the leading edge of what was a bow echo entered the state in northern Emmet county. Upon arriving outside of Wallingford I did capture very brief video of a gustnado on this leading edge. I estimate the location of this gustnado near Dolliver, IA given its' distance away from me at that time. An otherwise uneventful night as gusty winds and heavy rains were all that occurred...

I will try to get a vidcap of the gustnado up at a later time... Along with a few panoramic images of the shelf as it entered Emmet county.

Severe Squall Line

A mature squall line that continues to be capable of damaging winds in excess of 60 mph and the potential for quarter sized hail is moving swiftly to the east across South Dakota and northeast Nebraska. Current warnings cover the entire length of this line from DeSmet, SD to Pierce, NE...

Along its' current track the line would likely enter southwest Minnesota and northwest Iowa just after 1 AM this morning. Northwest Iowa is most likely to see any damaging winds from this squall line as it enters the state. Those in northwest Iowa should monitor conditions with their weather radio as damaging winds can often cause trees to fall which can produce damage to homes, especially upper levels.

My current plan will be to grab a few hours rest before getting up and heading out ahead of this squall line if it is still in tact as it nears Dickinson/Clay counties. More than likely I will attempt some lightning photography as it nears...

Iowa Upsets Chasers

Once again the state of Iowa has upset the chasing community with its' lack of cooperation over the past two days. Two straight days of moderate risk, and two straight days of utter disappointment for any storm chaser that was in the state. Both setups featured their own caveats, and both featured the opportunities for greatness, but both days have their caveats win out with no tornado reports and perhaps the highlight of a shelf cloud and some impressive winds this afternoon in southeast Iowa.

Thursday's setup featured a warm front which pushed well north of the state, leaving the state under a heavy capping inhibition between 850 hPa and 700 hPa. With no warm front to help trigger thunderstorms, only a weak remnant outflow boundary had an opportunity for greatness. Although it tried with several cumulus fields attempting to bubble up through the capping inversion, none would ever succeed. Thus, tack a point up for capping inversions with 12C temperatures at 700 hPa over Iowa as a bad chase day.

Today's (Friday) setup finally featured a strong trigger for convection as a cold front moved through the state, and an outflow boundary once again was expected to allow low level winds to remain southeasterly and aid in low level shear. The disappointment would come with winds remaining southwesterly ahead of the cold front, and the lack of a capping inversion allowing the whole cold front to be socked in with showers/storms from Noon onward. At least there were thunderstorms, albeit outflow dominant, that would let you chase something! Wind reports were consistent with at least three separate thunderstorms today, with winds ranging from 60-85 mph across eastern Iowa. Still, a day that would have offered tornado potential for the state would be ruined by a cold front with little inhibition and the lack of cooperation of the surface winds.

If anything can be learned from the past two days, trust instincts that a 12-13C temperature at 700hPa and no strong convergence in the lower levels will lead to nothing but struggling cumulus or blue skies. And, when a cold front comes into the state then you need the 12C temperature at 700hPa along with some southeast if not at least south winds to provide low level shear.

Here's to the hope that the more summer-like thunderstorms can provide some punch for the state with at least some great lightning and supercellular structure!!

Severe Weather Threat - June 19

While yesterday turned out to be another cap bust in Iowa that makes all those out-of-state chasers absolutely hate chasing in Iowa, today will definitely not be the same. Must cooler temperatures just above the surface in the lower levels will provide much less of a capping inversion, and with a must stronger wave in the mid-levels combined with significantly more convergence at the lower levels as well with a cold front moving southeastward. All of this will provide the southeast half of the state to see numerous thunderstorms, many of which may be severe with damaging winds and large hail.

Be sure to pay attention to the latest weather information via TV/Radio as thunderstorms near your area. While the risk of tornadoes is forecasted, it would appear that surface winds quickly turning southwesterly will decrease the low level shear dramatically, thus inhibiting the strong low level shear that was expected to aid in tornadic development.

Cap Bust??

With 700hPa temperatures in vicinity of the 12C range, the cap over central Iowa is quite strong... And with the ever decreasing convergence along any portion of the state it looks less and less likely that storms will fire before dark. I've decided to slowly work back westward towards home with an eye on the sky/radar if something does try to develop.

For now it appears that the Iowa cap will once again win over another fantastic parameter day in June...

Did manage to meet up with the TWISTEX crew and spend some time chatting with them, and grabbed a few pictures with the TIV2 as they were with the TWISTEX crew today. It was good to see all of them and hope to see you guys again!!

Chasing Live!!

Currently on Highway 18 just east of Cylinder, IA and will likely continue east towards Algona before sitting and waiting for a bit longer. Parameters look amazing, and once the cap is able to go then we should see very explosive development of supercells capable of significant tornadoes and hail.

Be sure to watch the chase live via the spotter network maps, the latest radar update from my laptop, and live video from my dash on the Iowa Chaser Live Chase Page!!

Significant Severe Weather - June 18

The updated SPC Day 1 outlook will continue the moderate risk of severe weather across much of northern Iowa and southern Minnesota. There is a significant risk of damaging winds, very large hail, and tornadoes across the area today. In fact, the updated outlook has increased the probability of tornadoes over northern Iowa and southern Minnesota. The morning thunderstorms will actually help increase the risk of tornadoes this afternoon/evening as the outflow boundary left in its' wake will interact with the warm front to create substantial low level shear. This would appear to once again be a very dangerous and life threatening situation over areas of the plains states today.

I will be chasing today across northwest Iowa, this blog will have the latest updates as I can provide them. As we near the afternoon initiation you may be able to view live video from my vehicle as well as track my location via the Iowa Chaser LIVE Chase Page.

Next update in regards to afternoon chasing and severe weather is expected in the early afternoon hours.

Morning Bow Echo

Thunderstorms cleared the state during the overnight hours, but not before providing several reports of hail and damaging winds as well as a tornado report in northeastern Iowa during yesterday evening.

Early this morning there is a bow echo that is entering northwest Iowa with the potential for damaging winds in excess of 60 mph. This storm has had a history of damaging wind gusts as well as marginally severe hail. The bow echo is a line of storms extending from near Beresford, SD southwards to near Pender, NE; and is moving east/northeast at 35 mph. A Severe Thunderstorm Watch has been issued for portions of northwest Iowa until 9 am for this line of thunderstorms.

This line of storms does appear to travel towards my location, thus will plan for its' arrival between 8:30 and 9:00 AM with the likelihood of a photogenic shelf cloud.

Severe Weather Update #1 - June 17

Severe and now tornadic thunderstorms are ongoing with the stronger warm front located along the Kansas/Nebraska border. Additional storms are likely as we continue through the afternoon and eventually congeal into more of a cluster or MCS of storms moving into west-central and southwest Iowa.

The other area of concern for severe weather, including tornadoes, will be over northwest/north-central Iowa where a convergent low level boundary associated with a weak low pressure system over South Dakota may trigger thunderstorms this afternoon/evening. Latest analysis indicates this wind shift is becoming very defined with strong instability along and east of the boundary. Effective wind shear values above 40 kts will support supercells when initiation occurs, and likely support tornadic storms through the evening hours.

I plan on chasing any development along this wind shift and weak boundary in northwest Iowa, thus stay tuned for additional updates!

Severe Weather Potential - June 17

The potential is there for significant severe weather across the western half of Iowa this afternoon and into the overnight hours. All modes of severe weather appear possible, including damaging winds, very large hail, and tornadoes. There are two areas of concern for severe weather today, both of which cover western Iowa...

The first and most likely concern will be over much of western Iowa, and likely be during the late evening or overnight hours. This severe weather threat will likely be for damaging winds and large hail, although a risk of tornadoes will exist, a more linear nature of thunderstorms may be expected. These thunderstorms will evolve from central Nebraska this afternoon as they initiate due to a shortwave and frontal system interaction. As the thunderstorms continue to evolve eastward they are likely to congeal into a more linear MCS capable of large hail and damaging winds as they enter into western Iowa.

Another threat for severe weather will exist during the afternoon/evening hours over mainly northwest Iowa, as well as southwest Minnesota. Similar to yesterday afternoon over South Dakota, a weak low pressure system in conjunction with a trough of low pressure and low level convergence may lead to thunderstorm development along a weak wind shift line. With even higher temperatures and dew points this afternoon yielding even higher instability amounts this will come as no surprise to see even stronger supercells off of this setup. These storms will be capable of all modes of severe weather through the evening hours, but similar to yesterday they should begin to weaken after sunset.

Additional updates are likely this afternoon as the severe weather threat evolves, I am watching the potential across northwest Iowa for the tornadic supercells similar to yesterday...

Severe Weather - June 6

Overnight convection associated with an MCS has continued to move through the state of Iowa this morning, and another cluster of precipitation is also moving across extreme northeast Nebraska and eastern South Dakota as well. This precipitation and its' evolution was a big question mark as to how it would affect the forecast for today's severe weather as it would influence the location of the warm front. It would appear that a cold pool has setup across parts of southeast South Dakota and adjacent areas of Minnesota and Iowa, however, areas behind this convection are already clearing indicating that there may only be a minimal effect from this mornings' precipitation across much of eastern Nebraska and western Iowa. In fact, elevated instability is already showing up across much of eastern Nebraska where clearing is already occurring.

Current SPC forecasts still indicate that they do not expect the front to have much of a northward surge at all today, leaving the primary focus for severe weather across southeast Nebraska and extreme northern Kansas. Once storms fire over that region this evening, they would then propagate northeastward along the warm front into western Iowa with the threats of damaging winds and large hail. This may be the more likely scenario, however, an eye will likely be kept on this front and its' northward progression throughout the day.

Severe weather will definitely be a possibility for areas south of a Kearney, NE to Sioux City, IA to Fort Dodge, IA line. All modes of severe weather would appear likely south of this line, including the threat of tornadoes in both discrete supercells and even in a more linear segments given strong shear values across the region. Once again however if the warm front is able to surge north across any portion of Nebraska/Iowa the threat of severe weather may move northward... Additional updates this afternoon may address this if it does indeed look to be occurring.

With prior plans in Vermillion, SD until ~7 PM I don't see any chasing occurring today unless the front can surge well north of its' current forecast. Tomorrow may be another chance with those details later tonight...

Severe Weekend Weather!

One of the more impressive setups for severe weather will take place beginning today and continue through the weekend for the northern/central Plains states. A broad western trough has finally moved into position to create southwesterly flow across the high plains today, and will make progress eastward over the next two days to continue this southwest flow into the central US. Today's severe weather threat will be held to the high plains due to meager moisture in place, and the more favorable upper level support is located across the high plains as well. Today's area of interest will include western Nebraska, northeast Colorado, and nearby adjacent areas including eastern Wyoming. The main threats with today's storms in the high plains will be very large hail and tornadoes given a strengthening low-level jet in the evening hours.

Tomorrow (Saturday) the lee cyclone begins to move off of the high plains and further east into Nebraska, with the aid of strong southerly jets just above the surface and an open Gulf of Mexico even at the surface we will see strong moisture return through the day and into the overnight. Moisture return will likely make it to near 60 or just above by Saturday evening, leading to only moderate instability across Nebraska and into western Iowa along/south of a warm front. The warm front location is somewhat in question, although this mornings' models locate this front from near Lincoln, NE to Clear Lake, IA and eastward towards Dubuque, IA. A dryline also situates itself southward from the low in central Nebraska, leading to other favorable areas for severe weather along this dryline through central Kansas. Shear values are favorable throughout this region, and initiation of storms appears likely nearest to the low pressure system in Nebraska and along/north of the warm front in NE/IA. Further south along the dryline could have explosive development if 700hPa temperatures well above 10C do not cap the convection. Storms that do develop and remain somewhat discrete will be supercellular in nature capable of large hail, damaging winds, and tornadoes. The more likely scenario will be for the storms to develop near the surface low and near the warm front, these storms will be capable of large hail/damaging winds. Given moderate moisture, storms may become surface based and definitely become capable of tornadoes as storms move along the warm front. An additional update on tomorrow may be posted later today if necessary...

Sunday is another day that holds very high potential for severe weather, given deeper and more sufficient moisture return south of the warm front that is once again expected to be draped from northern Nebraska through central/northern Iowa (Norfolk, NE to Sioux City, and near Clear Lake). While the warm front doesn't appear as defined on Sunday, likely due to convection debris/cloud cover from Saturday night, sufficient instability and lift would appear strong enough to erode the capping inversion that is once again present south of the warm front (10-12C 700 hPa temperatures). Once again storms should develop near the low pressure and near the warm front, capable of large hail/damaging winds/tornadoes given increasing shear values throughout the evening. As storms continue to develop near the low and further south along the dryline, it would appear that an MCS will once again develop and push east/northeast through Iowa capable of hail/winds. An update will be posted for Sunday either tonight/early tomorrow or potentially early Sunday.

I'm currently scheduled to photograph a wedding in Vermillion, SD on Saturday afternoon and early evening. Meaning I'm already in position for the potential on Saturday along the warm front and perhaps in position for Sunday in northeast Nebraska given an overnight stay. All of my chase gear will be with me needless to say...