Heat and humidity return along with severe weather for Tuesday

The next few days (things are uncertain for Wednesday so I will do a post on Tuesday evening about Wednesday's potential) will be very active in southern Manitoba with the help of heat and humidity fueling thunderstorm potential, get ready because it is going to be hot!

Severe Weather risk map July 19, 2016

Heat on Tuesday in the mid 80's or high 20's

Dewpoints soaring into the low 20's to mid 20's by afternoon in southern Manitoba.

The day Tuesday looks very unstable hot and humid,high temperatures will soar into the high 20's along with humidex readings in the high 30s to low forties combined there will be a chance for extreme heat warnings by Tuesday morning. Things will get really interesting in the afternoon and evening as a trough of low pressure approaches from the west.

Moisture: No shortage of moisture dewpoints will be advecting northwards along and ahead of the frontal system with values of 18 to 25C, PWATS of more than 1 inch or 50 to 70mm is likely.

Winnipeg Indicies CAPE and lifted index along with shear

Brandon Severe weather indicies for the next few days

CAPE INDEX for Tuesday

Lifted Index for Tuesday

Instability: No shortage of it (above) CAPES will be on the order of 2,000 to 5,000 J/Kg with afew places getting above 6,000. Lifted indicies getting from -7 to -13. This will be sufficent enough for explosive thunderstorm development come mid afternoon,, capping may be an issue though.

EHI for Tuesday at 5pm

Supercell composite for Tuesday afternoon

Significant Tornado Index July 19

Storm relative helicity july  19

Shear: High amounts of shear are available on Tuesday with a lot of Storm Relative Helicity available from 200 to 600 m2s-2, EHI of 5 to 8, and supercell composites from 12 to 25. Bulk shear from 50 to 60knots. This should be sufficent for the formation of dangerous supercells and possible tornadoes.

Trigger: Cold Front arriving from the west and a LLJ cranking up from the south ahead of the front.

Summary: Tomorrow will be a dangerous day weatherwise, a cold front will move through mid afternoon to mid evening, with serious CAPE levels there will be explosive thunderstorm development mid afternoon and evening. A high risk is present in the Western half of the province, and a moderate risk points east into the whiteshell. I expect storms to fire by around 4pm (if the cap doesnt hold) in western Manitoba where a high risk is present all modes of severe weather will be possible with huge discrete supercells likely early on, posing a risk of tornadoes and there could be a few touchdowns.  It will likely grow into a southeast or eastward moving MCS after organizing itself.  In both instances there will be a risk for very large hail up to golfballs and baseballs at best or soccerballs, yes soccerballs given extreme high CAPE, torrential flooding rains, ground scraping wall clouds and shelf clouds, winds in excess of 100km/h and frequent dangerous lightning. The risk for a few spinups or tornadoes will be present in the Red River Valley and Winnipeg by late afternoon and evening with the system, though not as high as a risk as the western half of the province. Western Manitoba mainly a afternoon event and the Red River Valley/Winnipeg, Eastman a late afternoon and evening event. Storms should clear by midnight for most. Remember this is subject to change and Justin on Manitoba weather centre should have updates through the day, I will be volunteering at the fringe festival in Winnipeg tomorrow 11am until 4pm at the patio or the beer tent feel free to stop by and say hi if you want.

I will have a quick update in the comments section by late afternoon and another post on Wednesday's potential late Tuesday Evening once storms clear. Remember to tweet reports to #mbstorm on Twitter and follow them there too!

Severe Weather Returns

A hot and humid airmass will be in place the next few days along with a trough of low pressure that will move through the region, so that will be the main weather maker the next few days as it moves east into Ontario. As a result severe weather will be commonplace as it passes through.

My own severe weather risk map for the night ahead, a high risk is present for the extreme southwest.

Severe weather risk map for Tonight as put out by the RDPS model

For the night ahead an area of low pressure will be moving into Southern Manitoba encountering a hot and humid airmass, thunderstorms have already developed in Western North Dakota and they are expected to move into southwestern Manitoba over the coming hours. Let's have a lookk and see what ingredients are present here:

Moisture: Dewpoints will be in the upper teens low 20's for most tonight mixed in with humidex readings in the mid 30 range should give sufficent amounts of moisture for storms to drop, Excess of 50mm+ in less than a hours time possible.

Instability: CAPES on the order of 2,000 J/kg in the central parts of the province to 3,000 J/Kg in southern parts of the province overnight. A few places along the border could see CAPES of 4,000 to 5,000 J/Kg. Along with Lifted indicies of -5 to -11. Supercells although weak will be possible in the southern half of the province given Bulk Richardson Numbers in the high 30's to near 45. Anything less than 45 means supercell potential.

Shear: Not that impressive but it should be enough to sustain severe storms with 30 to 40 knots of bulk shear expected. That should supply the chance for some funnel clouds in places and maybe a few weak tornadoes, the chance is only 5% though.

Trigger: Frontal system will be moving Northeast overnight bringing in a severe weather threat, as it encounters the hot and humid airmass.

So what do we expect overall???
As thunderstorms continue to develop in North Dakota, they will push northwards overnight and if not either way given the high or extreme levels of instability I expect the storms to either grow upscale into a MCS or elevated thunderstorms that will develop in the form of a MCS with the likelihood of north and east expansion in a squall line/bow echo/derecho. As a result severe weather will be possible through the late evening and overnight timeframe, given high MUCAPES baseball sized hail will be possible for most, severe winds in excess of 90km/h, Flash Flooding rains with very intense frequent lightning. Most of the severe weather will be affecting the high risk area from 7 to 11pm in southwest Manitoba, moderate risk area from 11pm to 5am in the rest of the western half of Manitoba into Winnipeg and the Red River Valley. Areas from the red river valley east the slight risk area after sunrise. Stay tuned to watches and warnings at http://weather.gc.ca/warnings/index_e.html?prov=mb Overnight lows will be mild and it will be muggy with lows of 21C in Winnipeg and 19C in Brandon with high teens and low 20's for most and humidex values of 25 to 30C. Thunderstorms should clear by morning leaving behind another sunny and muggy airmass.

Monday another round of severe weather 

 

High dewpoints stay in place on Monday in Southern Manitoba, fueling storms.

Severe weather risk map for Monday as put out by the RDPS model

Severe Weather including Tornado risks are possible in the red river valley including Winnipeg tomorrow.

Monday looks like another busy day weatherwise as a potent cold front drives through the province, there will be a setup for decent severe weather this time in the Red River Valley, hot and humid conditions will be present in the afternoon with humidex values near to above 40C. Let's look at the details about tomorrow's atmospheric conditions...

Moisture: Dewpoints in the low 20's and humidex values in the 40's, PWATS in excess of 30 to 50mm will provide significant amounts of moisture for storms to drop.

Instability: Will be off the charts tomorrow afternoon, 3,000 to 4,000 MUCAPE, lifted indicies in excess of minus 7 to minus 12. Enough for baseball sized hail again given MUCAPE fuels the updrafts in thunderstorms which creates hail.

Shear: Very impressive!!! 50 to 60 knots of bulk shear expected giving storm organization into potential supercells and continued storm growth.

Trigger: A powerful cold front moving in from the southwest in North Dakota.

It will be a very busy day weatherwise as we approach the day Monday, as mentioned a powerful cold front will go through a hot humid airmass, as a result I expect storms to fire in the western red river valley and northern north dakota in the late afternoon hours. They will likely grow upscale into a thunderstorm squall line by mid afternoon into the evening.  There will be a potential for baseball sized hail, frequent lightning, and heavy rainfall in excess of 100mm an hour. Winds will also be a concern as hefty amounts of shear are available for thunderstorms tomorrow. The risk for tornadoes is there in the red river valley and eastern manitoba tomorrow afternoon and evening with supercell potential.Storms should weaken as they move north into Northern Manitoba by late evening. Watches will likely be issued tomorrow so stay tuned to weather.gc.ca for details. High temperatures will be in the mid to high 20s with humidex values going above 40C for much of the south. Clearing should come in by mid evening with temperatures dropping into the mid teens for overnight lows and much drier air will be in place.

Showers are expected on Tuesday with the odd shower or thunderstorm around that will be with the presence of a powerful low pressure system that will be centered over the interlakes, severe weather will not be anticipated on Tuesday with highs just getting above 20C. Warmer weather will arrive by mid week into late week.

I will update in the morning or early afternoon tomorrow regarding the severe threat, in case it changes.

More storms possible this week

The next  few days will be a little unsettled and it could get interesting as a few shortwaves moves through our area, temperatures will be mild however.

Today a shortwave will be moving through Southern Manitoba, and will be the focus for severe thunderstorm development in the interlakes and central Manitoba. There already is a severe thunderstorm watch in place for the interlakes and central Manitoba and may be expanded southwards as the evening goes on. Dewpoints in the 15 to 20C range and temperatures in the mid 20's it will give way to Lifted indicies in the -5 to -7 range with MUCAPES from 500 to 1,500 J/kg there will be sufficent lift available. Coupled with Shear from 10 to 30 knots I suspect storm organization will be quite possible through the evening hours. Along with PWATS of >1 inch (40mm) likely. Put it altogether the trough should be enough to spark thunderstorms in the interlakes regions through the day and as it does storms will drift southeastwards through the late afternoon and evening hours, given the high MUCAPE expect hail to be a concern with toonie size hail and frequent lightning a possibility. Also with PWATS quite high I expect that there will be no doubt some flooding potential if storms stay over 1 area for a decent amount of time. Storms should clear by late evening before exiting the province by midnight or weakening. Daytime highs should be in the mid twenties with humidex values reaching the low to mid thirties.

Wednesday will even be a more interesting day, high temperatures in the mid to high 20's and humidex values in the mid thirties, and dewpoints from 15 to 20C combined with MUCAPES from 1,000 to 3,200 J/kg and Lifted indicies from -3 to -7 will fuel thunderstorm potential. Shear will be on te order of 20 to 45 knots (storm organization) as well with PWATS in the 35mm range (rainfall). Put that altogether with a cold front going through mid to late afternoon into evening, severe weather will be a distinct possibility (although scattered in nature) with large hail given the high CAPE values and potential for some strong wind gusts with shear enough to give storms some wind to work with. Dangerous Lightning and rainfall in excess of 25mm may be a concern as well. The storm threat will ease by late evening as the front passes through as drier air begins working in.

Drier and more stable weather expected for the end of the week into the weekend, before more storms are possible by the end of the weekend.

Hot Muggy Conditions to Spawn Severe Weather

The rest of the day will be one of those evening's that you know something might be brewing, heat and humidity will be in place from a moist southerly airmass resulting in another risk for severe weather that could keep people watching the skies.

Tonight a severe weather event will evolve as a trough of low pressure system comes up from Montana and interacts with a hot and humid airmass that will spawn conditions for severe thunderstorms. Let's have a look at ingredients, I used less equations this time considering I already knew we were going to have scattered severe storms and high convective potential.

Moisture: Dewpoints no lack of it at least 15 to 20C for much of southern Manitoba which will give way to PWATS of 35 to 40mm. Making way for heavy rainfall in storms as much as 70mm may be possible.

Instability: High levels of Instability in Place with a wide swath of 2,000 to 4,000J/Kg moving across the south overnight. Hail could result from these extreme instability numbers, and it could be as large as toonies to golf balls. SWEAT Index's will also be inbetween 400 and 600 with 668 for Brandon and 524 for Winnipeg. Which means supercells are possible with Tornadic Potential. A BRN index of about 10 to 25 across the south which means supercell potential. 

Shear: With storm relative inflow being in the 200 to 500m2s2, there will be a decent amount of shear to work with that could result in damaging wind gusts up to 70km/h or more.

Trigger: The trigger for the severe storms is a warm front that is situated in the red river valley and a cold front that will move through in the late overnight hours.

Severe weather will be possible overnight in Brandon, tornado, hail potential.

Severe hail possible in Winnipeg overnight.

Scattered thunderstorms are expected in the red river valley and southeastern Manitoba this evening before the main event arrives to end the evening, some may be severe as well. Overall this thnderstorm complex that is out  Southeastern Saskatchewan is expected to slowly move into southwestern Manitoba during the evening and overnight hours, eventually pushing into the Red River Valley after midnight. There will be the potential for embedded supercells with funnel clouds and weak tornadoes possible in early stages. As it treks east potential for some or most of the thunderstorms to be severe with damaging wind gusts in excess of 70km/h, severe hail as big as toonies to golfballs, frequent lightning due to the higher CAPE Values and flooding rains depending on how fast the line moves. Watches and warnings may be issued so please stay tuned to weather.gc.ca for updates. The severe weather threat will ease by morning hours. Overnight lows will stay in the high teens under stormy conditions.


Saturday More Mugginess???

Considering the frontal system is not expected to pass through until about 7pm tomorrow high amounts of moisture, shear and instability running from 1,000 to 3,000J/Kg of CAPE will result in another potential round of severe weather this time for the Red River Valley and southeastern Manitoba, as dewpoints approach 20 degrees with daytime high's getting to about 23 to 25 degrees. Likelihood for large hail, damaging winds and heavy rainfall.The front should pass by at around 7pm with storms likely. Drier air should start working into the area by about 8pm from the southwest part of the province which will be situated there the whole day.


Cooler weather in the low 20's is expected through sunday and into the week before hotter weather arrives mid to late week. Enjoy the storms!

Severe Weather for Saturday Night....

Fathers day ccould very well be a day to remember in Southern Manitoba, a significant severe thunderstorm threat is in the cards tonight with the potential for the first memorable storm of the year.

Tonight could very well be a very active night across southern Manitoba as a frontal system that developed out in Western Saskatchewan will move into southern Manitoba overnight, it appears that it is already on the doorstep accorddingg to this Rain Alarm image. The low pressure system will slide eastwards gradually bringing the warm front northwards as it moves East, which means that the severe potential will be north of the border rather than it being south of the border in which many ways it has before.

For the night ahead with the convection already developed the severe potential will increase substantially as all of the necessary ingredients including enough shear flow into the developing storm. Let's look over the ingredients using Brad's mist principle.
Moisture: No shortage of mositure dewpoints will skyrocket overnight into the mid to high teens
Instability: Lots of it should support thunderstorm sustaining CAPES on the order of 2,000 to 3,000 J/kg, LI's -5 to -10, Total Totals of 57 in Winnipeg, K Index of 41 in Winnipeg, Sweat Index of 494 in Winnipeg, BRN of 14 in Winnipeg K index of 46 in Brandon, Total Totals of 60 in Brandon, K index of 14 in Brandon, SWEAT index of 662 in Brandon. Here is what they all mean...
Shear: Enough to support bow echos and development and organization of storm cells. Bulk Shear from 50 to 75 knots. Storm Relative helicity 200 to 450 m2 s2.
 Trigger: Frontal system arriving from the west with warm front slowly moving northwards during the overnight.

The severe weather threat will involve a development of a squall line of thunderstorms that will travel through southern manitoba in the coming hours, with the potential of bow echo development which could very well evolve. Factoring in all things the main concerns will be a hail and wind threat, with high levels of moisture in the atmosphere there is a risk for severe flooding and torrential downpours. Hail will also be a concern with sizes up to golfballs once again expected, and if the storms become outflow dominant there very well could bring gusts in excess of 100km/h. Frequent lightning will also be a concern with the potential for dangerous cloud to ground strikes.

The timeline of the storms will vary on speed of the system, it looks like the southwest will be hit after midnight, Red River Valley at around 3am, Eastman early morning and Northwest Ontario during the day.

Severe Weather Threat: Large Hail as Large as Golf Balls, Frequent lightning, Flooding torrential rains, Damaging winds as high as 100km/h or more. No Tornadoes risk is low however.

More Storms Expected during the day Sunday, some may be severe as well.

Severe Weather Summary June 16,2016

The last few days have been very active in southern Manitoba with severe weather occurring on the night of June 16 and the morning of June 17, 2016.

A trough of low pressure moved over southern Manitoba on Thursday evening, we were expecting severe storms to fire and move west to east in the evening, however due to capping (which is a layer of warm air at the troposphere that prevents storms from developing) in the evening storms never fired in the southwest which is a good thing because they didn't need anymore rainfall. As the trough continued to move east in the Red River Valley it encountered an area where more elevated lift was present at 850mb, also as I had expected the capping weakened at around 2am in the Red River Valley and as a result massive storms fired in the Manitou, Pilot Mound areas at 2am.

The storms went on to produce golf ball size hail and continued to strengthen, there was at least a few signs on radar of rotation by snowflake which is at the border of MB/ND by Pembina Valley Provincial Park. The storms then developed into a line which gave off frequent and constant lightning, hail to golf balls, flooding rains, and some damage from wind but not a lot. The storms missed Winnipeg completely at times it looked like they were coming straight at me on radar, however if it had of hit there probably would have been power outages. Here are some photos of the storms that occurred that night... Courtesy goes to the people on the twitter accounts...

The storms not only caused chaos in the Southern Red River Valley but they also affected Winnipeg.
Storms fired at around 5am west of Winnipeg and entered at around 6am and was the culprit for a tree explosion in the Tuxedo area of Winnipeg, tree splinters drove through a duplex building walls and windows. There was also numerous reports of street flooding with the 2 thunderstorms that hit the city. As much as 3 inches fell in the south end of the city, that was hardest hit.

Here are some photos of the tree that was exploded in the Winnipeg area Friday morning...

Lots of street flooding on Friday morning...

Flooding also occurred in Saint Anne photo from Cathleen Roy, and a storm cloud in La Broquerie from Tracey Benson Kokil. The rainfall totals from the storm are as follows....

The storms were big and we are expecting a lot more, I am coming up with another blogpost in a bit with the storm potential about tonight...

Severe Thunderstorm Outlook for Thursday

Today is expected to be a busy day weatherwise and it will potentially be the most active that we have seen in a long time, a few tweaks to the risk area map I have moved the high risk area further north as the cold front will be affecting those areas more than I first thought and the high risk area is extended further east given forecasted radar imagery. Let's have a look at the graphics before we go into quick details....

Cold front going through later in the evening will trigger severe storms, some may be supercells. Put out by AWWS.

Supercell potential mid evening in southwest and western Manitoba by the WRF Model,
Bow echo and MCS possible overnight.

Thursday Thunderstorm Risk (red is severe thunderstorms) during the day put out by the RDPS Summer Model

Thursday night thunderstorm risk map put out by the RDPS Summer Model (Severe Weather is possible in Red, Near Severe in Orange).

 Nothing muc as changed in terms of what we are expecting, except the tornado risk has dissapeared completely for the Red River Valley overnight on Thursday into Friday. What I am expecting is that severe thunderstorms will develop in Eastern Saskatchewan late afternoon and drift into Western Manitoba by evening along and ahead of the cold front, discrete supercells will likely develop by evening posing a tornado risk with 100km/h winds, golf ball to baseball size hail, heavy rainfall and frequent dangerous lightning. Please Read Environment Canada's latest forecast discussion here: http://kamala.cod.edu/offs/CWWG/focn45.chunk.html .Please stay aware of watches and warnings in your area, and take shelter when dangerous weather threatens. Follow all the info at my page: michaelmcgregor7.wix.com/southmbwxcentral. Here are some Tornado safety precautions from http://www.getprepared.gc.ca/cnt/hzd/trnds-en.aspx and http://www.getprepared.gc.ca/cnt/hzd/trnds-drng-en.aspx  : 

Also safety tips from TheWeatherNetwork can be found here

"Warning signs of a potential tornado

Warning signs include:

• Severe thunderstorms, with frequent thunder and lightning
• An extremely dark sky, sometimes highlighted by green or yellow clouds
• A rumbling sound or a whistling sound.
• A funnel cloud at the rear base of a thundercloud, often behind a curtain of heavy rain or hail."

"If you are in a house

• Go to the basement or take shelter in a small interior ground floor room such as a bathroom, closet or hallway.
• If you have no basement, protect yourself by taking shelter under a heavy table or desk.
• In all cases, stay away from windows, outside walls and doors

If you live on a farm

• Livestock hear and sense impending tornadoes. If your family or home is at risk, the livestock will be a non-issue. If your personal safety is not an issue, you may only have time to open routes of escape for your livestock. Open the gate, if you must, and then exit the area in a tangent direction away from the expected path of the twister.

If you are in an office or apartment building

• Take shelter in an inner hallway or room, ideally in the basement or on the ground floor.
• Do not use the elevator.
• Stay away from windows.

If you are in a gymnasium, church or auditorium

• Large buildings with wide-span roofs may collapse if a tornado hits.
• If possible, find shelter in another building.
• If you are in one of these buildings and cannot leave, take cover under a sturdy structure such as a table or desk.

Avoid cars and mobile homes

• More than half of all deaths from tornadoes happen in mobile homes.
• Find shelter elsewhere, preferably in a building with a strong foundation.
• If no shelter is available, lie down in a ditch away from the car or mobile home. Beware of flooding from downpours and be prepared to move.

If you are driving

• If you spot a tornado in the distance go to the nearest solid shelter.
• If the tornado is close, get out of your car and take cover in a low-lying area, such as a ditch.

In all cases

• Get as close to the ground as possible, protect your head and watch for flying debris.
• Do not chase tornadoes - they are unpredictable and can change course abruptly.
• A tornado is deceptive. It may appear to be standing still but is, in fact, moving toward you"

 The severe thunderstorms/supercells may form into a severe thunderstorm complex or MCS by evening once they transition they will drift eastwards into the Red river valley, interlakes, Eastern Manitoba late evening and overnight with large hail as large as baseballs, damaging wind potential 80km/h plus, frequent lightning and heavy rainfall near 25 to 75mm. They will weaken once they near the Ontario border or cross into Minnesota. Storms possible Friday afternoon in the Red River Valley/East MB but a slim chance. Will keep you updated on Twitter, Manitoba Weather Center and Southern Manitoba Weather Hub. Here is a great page with information on the weather terms I used such as squall line, supercells, MCS and bow echo's.