Severe weather returns to Minnesota; storms will stay north of the Twin Cities

Severe weather returns to Minnesota after late June wind storms caused $17.8 million dollars worth of damage, and Xcel Energy called it the most significant power outage in the state’s history. 

Storms today will be mainly confined to the Northland, and Arrowhead regions of the state where a stalled frontal boundary is draped across the international border.

With temperatures well into the 90s across much of the state, and with dew points at or above 70 through the afternoon, there will be more than enough energy, or juice to initiate storms by the evening.

Tropical air and lifted indices approaching -10°C on the RAP model will more than support thunderstorms, and possibly super cells.

I believe storms will form over north central Minnesota, and then move east-southeast during the evening.  Supercells will eventually build into a linear MCS as the day progresses.

The primary severe weather threats are wind and large hail.  Winds will be out of the west at 500 mb, and at the southwest 850 mb.  Had the winds been more southeast at 850 mb, I believe there would be a heightened risk of tornadoes.  Powerful winds, as we saw in the Twin Cities, can cause low-end tornado-like damage.

Persons camping in the Boundary Waters Canoe Area and along the North Shore will definitely need to keep an eye to the sky today.  Unfortunately, these areas are isolated, and having means of receiving weather information can be difficult.  This is why I always pack a weather radio that can run off AC power, batteries, and even hand cranking, as a last option.  These storms will mean business today, and being caught outside far from shelter is a worst case scenario.  Stay tuned for additional updates on Twitter and Facebook today!

RS

Minnesota Severe Weather Awareness Week 2013

This week is Severe Weather Awareness Week in Minnesota.  While we have been plagued by snow and cold lately, now is a good time to prepare for severe thunderstorms as we head towards the summer months.  On Thursday, there will be a statewide afternoon and evening tornado drill at 1:45 and 6:55 p.m., respectively.

An understanding of basic terminology is fundamental for severe weather safety.  Here are some terms you will see in the media, from the National Weather Service, and on this blog:

The Storm Prediction Center issues an outlook leading up to when dangerous weather is likely.  These outlooks may be issued as far out as eight days prior to the event.  For a better understanding of these outlooks, this post does an excellent job explaining the Storm Prediction Center products in-depth.

When conditions become favorable for organized severe thunderstorms and/or tornadoes to develop, a watch is issued by the Storm Prediction Center.  It means weather conditions are favorable for dangerous weather to occur. In other words, a "watch" means watch out for what the weather could do, and be ready to act accordingly. You may wish to alter or have a back-up plan for any outdoor activities or travel.  A typical watch duration is six to seven hours, but it may be cancelled, replaced, or re-issued as required.

A warning is issued by the local National Weather Service office when the weather event is imminent or occurring somewhere in the defined warning area, and that people need to take shelter as soon as possible.  These warnings can last as long as 45 minutes to an hour.  New to 2013 is the use of “impact based warnings” by the National Weather Service to emphasize threat and impacts to improve public response.  More information can be found in the video below:

Do you have enough “safety nets” in place for receiving these weather alerts?  Every person should have multiple means other than the outdoor warning sirens for being aware of approaching severe weather.  As I have stated many times before, sirens are only meant to be heard OUTDOORS as a means to get inside a sturdy structure when sirens are sounded.  In addition to the outdoor siren, conventional NOAA Weather Radio should be in every home, much like smoke detectors.  These radios can be set to alert you in standby mode to all or certain hazards within a county or counties, especially during hours of sleep.  It also provides general weather information 24 hours a day, seven days a week.

Many cell phones now feature the ability to receive Wireless Emergency Alerts (WEA), which allow push notifications when the user is within range of an affected hazard area. There are still compatibility issues with this system, mainly with AT&T’s new high-speed LTE network, so I can not recommend this system at this time until it works with all of the phones on the market.  For those who are unable to benefit from WEA, here are a couple apps which work nicely:

• iMap Weather Radio ($9.99, Android & iOS)
• American Red Cross Tornado Warning & Alert App (Free, Android & iOS)

I personally prefer iMap Weather Radio as it allows selectable alerts from virtually every weather hazard possible.  Another benefit is that it uses GPS tracking to only alert when the phone is within the watch, warning, or advisory boundaries, unlike NOAA Weather Radio, which is currently limited to entire counties.  This app also features basic radar and Storm Prediction Center outlooks.  For $9.99, it is a bargain in my opinion considering the cost of weather radios run $30 or more.

Some tornado statistics.  From 1950 to 2010, Minnesota averaged 27 tornadoes a year.  Over 75% of the tornadoes during that period occurred in the months of May, June, and July.  The majority of tornadoes happen between 4 and 6 p.m.  When it comes to tornado intensity, Minnesota tornadoes tend to be on the low-end, with more than half being F/EF-0 and F/EF-1 strength.  The last F/EF-5 tornado in the state was in June 1992, affecting the southwestern town of Chandler.  An Enhanced Fujita scale table is found here.

If you have any severe weather or safety questions, please post them below!

RS

Healthy dose of rain this weekend?

A strong low pressure area is forecast to track across Minnesota this weekend, bringing with it a very good chance of any decent precipitation in almost two months.

Many parts of the state could see upwards of an inch of much-needed rain or more from this powerful storm system.  This will no doubt decrease the degree of drought that plagues much of the state.

Taking a closer look at the Twin Cities, some of the models are spitting out about an inch of rain.

Severe threat?

Over the last couple days, the Storm Prediction Center has highlighted southeastern Minnesota in their daily outlooks for the possibility of severe weather on Saturday.

I’m not quite buying into this scenario, at least for Minnesota.  By Saturday morning, it appears we will dealing with cloud cover which will inhibit convective activity later in the day.  Both the European and American GFS model illustrate this.

Euro:

GFS:

Temperatures are going to struggle to get into the 60s I believe, which will diminish any substantial severe weather threat.  Dew points may get into the 60s, but the lack of any daytime heating will make moisture content irrelevant.  Instead, much of state will be dealing with quality, soaking rains.

RS

Storm reports from Wednesday night

Thunderstorms developed across far western Minnesota during the late afternoon and pushed eastward.  As night came, the air began to stabilize a bit, and the storm complex started to lose signs of life.  During the initial hours, severe weather did occur and large hail fell.

Here is a listing of hail reports meeting severe criteria received by the National Weather Service from Wednesday night.  Golf ball size hail occurred near Donnelly in Stevens County.  Half-dollar size hail was seen near the cities of Morris and Benson.

Another reason the storms fell apart as they approached the Twin Cities was that conditions were not favorable for severe thunderstorms.  The 7 pm observations from Chanhassen indicates the atmosphere was capped.  In addition, CAPE values (an indicator of instability) were low, indicating a minimal chance for severe thunderstorms.

This has been the story all year long. It seems as if one ingredient has always been missing for severe weather, leading to many busts.  It makes me almost believe that “It’s 2012, storms just don’t get real bad here”.

RS

A few severe thunderstorms with gusty winds possible today

After a long stretch of quiet weather throughout July and first half of August, the threat for severe thunderstorms returns to the area today as a strong cold front will be moving through Minnesota during the evening hours.

Temperatures are expected to be near 90 degrees across southern Minnesota, with dew points approaching 60 degrees will create just enough instability for convective activity later on today.

Damaging winds are the greatest threat from any of the thunderstorms today as storms are expected to be linear in nature along the cold front pushing eastward.  Winds will have the potential to reach 55 to 60 mph.

The Storm Prediction Center highlights this below:

THE GREATEST SEVERE POTENTIAL HOWEVER -- LIKELY IN THE FORM OF DAMAGING WINDS ASSOCIATED WITH A WELL-ORGANIZED LINE AND POSSIBLY SOME BOWING STRUCTURES -- IS EXPECTED ACROSS A PORTION OF THE ERN DAKOTAS BUT PARTICULARLY MN...FROM FROM MID AFTERNOON THROUGH EARLY EVENING. SOME THREAT MAY CONTINUE EWD INTO WRN PORTIONS OF THE UPPER GREAT LAKES REGION LATER IN THE EVENING...BUT DIURNAL COOLING/STABILIZATION SUGGEST LESSER POTENTIAL THAN EARLIER/FARTHER W.

Timing.  Storms are expected to develop during the early evening hours in western Minnesota from near Bemidji to Alexandria.  This is where the greatest concentration of energy for initiation will be located.

The line should be into the Twin Cities around 9 to 10 pm, but intensity should diminish once the sun sets and we lose daytime heating, allowing attrition to come into play.  Storms this time of the year are very dependent on heating.  Here is one of the high-resolution models at 9 pm tonight (click the image to enlarge):

I believe the threat for damaging winds will be the greatest west of an International Falls, Grand Rapids, St. Cloud, and Worthington line.  The Twin Cities may see a few strong/severe storms storms depending on when the line begins to lose some of it’s punch.  It will be something to monitor later today.

RS

Urgent notice for Bemidji residents

THE FOLLOWING MESSAGE IS TRANSMITTED AT THE REQUEST OF THE BELTRAMI EMERGENCY MANAGEMENT:

“EMERGENCY TRAVEL ONLY IS BEING ADVISED IN THE CITY OF BEMIDJI AT THIS TIME DUE TO EXTENSIVE STORM DAMAGE. THIS DAMAGE INCLUDES NUMEROUS POWER-LINES DOWN...NUMEROUS AND SIGNIFICANT TREE DAMAGE AS WELL. ALL PHONE SYSTEMS ARE DOWN EXCEPT FOR 911 FOR EMERGENCY CALL ONLY.”

Some of the storm reports from the Bemidji area:

• Bemidji [Beltrami Co, MN] law enforcement reports TSTM WND DMG at 07:00 PM CDT -- numerous trees down throughout the city of bemidji. street flooding as well.
  
• Bemidji [Beltrami Co, MN] broadcast media reports NON-TSTM WND DMG at 07:05 PM CDT -- public report of a 60 ft spruce tree broken off about halfway up the tree with other limbs down in the area ... posted on kvly facebook site

In addition to damage in Bemidji, visitors at Lake Itasca State Park are trapped inside the park due to trees down across the exit.   Winds were estimated around 80 mph.

Radar image from earlier in the evening:

RS

Active Sunday evening across Minnesota

A line of strong to severe thunderstorms moved through west central and east central areas of Minnesota Sunday night causing high winds, flooding, and numerous funnel cloud reports.  The line weakened as it approached the Twin Cities as drier, more stable worked into the system from convection earlier in the day.

Dew points were most impressive across northeastern South Dakota and far west central Minnesota at 7:30 pm Sunday.  Despite the models printing a large MCS (mesoscale convective system) coming into the Twin Cities by 10 pm or so, I knew it was going to lose a bit of punch, and questioned whether it would be severe by the time it arrived into MSP.  I think weather folks tend to get too excited about what the computers are telling them and assume the worst without looking at other information.  One can not forget the basics, such as surface observations.  Have to ask yourself, “Does this model solution make sense?”

Only one official tornado report was received Sunday east of Wheaton, Minnesota.  There were many reports of funnel clouds and thunderstorm wind damage across west central Minnesota.  The highest wind gust observed was 77 mph in the town of Cosmos at 9:56 pm.

The National Weather Service offices were busy issuing warnings all night.  Tornado warnings clipped the far west metro, and severe thunderstorm warnings extended all the way to the St. Croix River.  The Twin Cities saw heavy rains, two to three inches, on already saturated ground, triggering flash flood warnings.

It was definitely a busy night, and we could see more storms on Tuesday.  Look for additional updates as they are warranted!

RS

Severe weather possible Thursday

Warm and humid air will work it's way into Minnesota by Thursday, which will create an unstable air mass for thunderstorm development as a cold front moves through the area during the evening hours.

Isolated severe thunderstorms will be possible in the warm sector (behind the warm front and ahead of the cold front) across the southern two-thirds of Minnesota Thursday night.

The veering of winds is much more impressive with this system than the Sunday storm.  The upper, lower, and surface level winds are forecasted to be from the southwest, west, and southwest, respectively.

250 mb:

500 mb:

850 mb:

The wind shear profile seems to be favorable for tornadoes, and surface-based convection is likely.  I wouldn’t be surprised to see a tornado watch issued during the afternoon hours on Thursday.

You will want to keep an eye to the sky if you have Thursday outdoor activities, as this storm will mean business if we get the necessary daytime heating.

RS

Did the Sunday storms produce a tornado?

As expected, a line of strong to severe thunderstorms rolled across Minnesota Sunday night ahead of a cold front.

Widespread damaging wind reports were received throughout the state, and at one time, 18,000 Xcel Energy customers were without power in the Twin Cities.  Some of the more interesting storm reports received that involved structural damage are below.  The majority of the wind reports involved tree damage.

Things really become interesting after 8 pm when a tornado warning was issued at 8:18 pm on a cell heading into southwestern Scott County.

* AT 814 PM CDT...RADAR INDICATED A STORM CAPABLE OF PRODUCING A TORNADO. THE MOST DANGEROUS PART OF THE STORM WAS 6 MILES SOUTHWEST OF BELLE PLAINE...OR ABOUT 4 MILES EAST OF HENDERSON...AND MOVING NORTHEAST AT 50 MPH.

Strong rotation was detected on radar as the cell travelled between Belle Plaine and Jordan.  Damage in the Belle Plaine area included, “Roof blown off house, shed down, and a 48 foot grain bin blown into a field.”

Was this a tornado?  Based on what I have seen on radar, there is pretty good evidence that it was.  However, the National Weather Service in Chanhassen will conduct a formal damage survey to determine if the damage was caused by straight-line winds or a tornado.  If it is indeed ruled a tornado, this would be the first tornado to impact Scott County in almost two years.  The last tornado in the county occurred on June 26, 2010 near Elko New Market.  Damage was reported to trees and a silo in that storm.

RS

Storms still set to arrive tonight

Storms are projected to develop late this afternoon across west central Minnesota and push through the state during the night ahead of a cold front sweeping through today.

All of the models are depicting a line of storms, some of which will be severe within embedded cells, lining up north to south across the state by the evening hours.

One inch or greater hail is the primary concern with these storms today, according to the Storm Prediction Center.

There is also an isolated tornado threat, mainly during storm initiation across a large portion of the state.  I still believe the greatest threat for tornadoes will be north of a Brainerd line.

Keep it tuned here for additional updates throughout the day!

RS

Severe weather likely to close out the weekend

A cold front is expected to sweep through Minnesota during the day Sunday, which will bring a good chance of thunderstorms, some severe, to the region.

Cold front position at 7 pm Sunday:

Out ahead of the front, conditions will be hot and muggy on Sunday.  Temperatures are forecasted to be in the mid-90s with dew points approaching 70 degrees.

Temps:

Dew point:

This will result in a very unstable atmosphere for thunderstorm development.  There will be more than enough energy for storm initiation once the cold front begins to move into the state.

The greatest risk for severe weather will be over the central and northern sections of Minnesota.  Roughly from the St. Cloud area, and northward.  However, an isolated severe storm is possible for the Twin Cities metro.

The overall primary concerns from the Sunday storms are large hail and damaging winds.  A tornado risk does exist closer to the intersection of the cold and warm fronts in northern Minnesota – Brainerd lakes vicinity and north.

If you are going to be out on the lake during the latter half of the weekend, make sure to have a NOAA Weather Radio with you, and keep an eye on the western horizon for darkening skies!

RS