Another Weekend of Unsettled Weather

(Some Information Provided by Brad From A Weather Moment)

Today will be another beautiful day for the start of the Red River Exhibition as temperatures near the mid 20C range anywhere in the southern part of the province, with very little cloud cover to contend with. Although things are about to turn active for the weekend with the arrival of more low pressure systems that will move over our region.

An area of rain/storms will form in SE Sask, Western North Dakota tonight at 6pm and it will drift eastwards throughout the night.

An area of low pressure is expected to trek eastwards across the prairies and northern plains today, as a result things will become more favourable for the development of thunderstorms tonight. As the system tracks into SW Manitoba and Western North Dakota tonight, storms should have very little issue popping up. With decent instability, the storms should quickly grow into an area of rain with embedded thunderstorms and likely trek East-Northeast. The area of rain will get to the SW by late evening, Red River Valley late overnight and get through to eastern Manitoba by the morning and afternoon. With little LLJ influence in place it will likely keep the thunderstorm threat to a minimum with the rain that pushes through. Although the odd rumble of thunder cannot be ruled out. Some Models are forecasting up to near 10 and 15mm of rain over the next 3 to 6 hours. This system looks a lot similar to last weekends storm system, so it may end up prompting more stormchasers to head out if severe weather develops. As the area of low pressure tracks through the rest of Manitoba tomorrow, we will see the chance for showers and thunderstorms through much of the Red River Valley in the afternoon. Chances will be higher North of Morris, that would include Winnipeg and areas North.
 

Another Round Of Storms, Possibly Some Severe On Sunday

The threat of severe weather returns to Southern Manitoba on Sunday as another powerful low pressure system moves into the area. Dewpoints will rapidly climb up into the high teens/low twenties on Sunday, especially in regions of SW Manitoba as a powerful southerly flow develops out ahead of the incoming storm system. CAPE values will likely climb past 2000 J/Kg with decent shear. Tornado potential exists and looks to be near the Western Red River Valley, including Pilot Mound,Crystal City, Manitou, Pembina Valley Provincial Park, Morden, Winkler, Altona, Emerson and Morris. All areas South and West of Winnipeg. The closer to the USA border you live, the greater the risk for tornado producing Supercells. As the storm system travels eastwards into the Red River Valley by evening things should blow up fairly good, with widespread thunderstorms growing quickly into an MCS. Damaging Winds and large hail will most certainly be a threat for areas in the RRV. Sunday's forecast is sensitive to the systems speed. If it ends up being slower everything will be further West, If faster everything will be further East.

Details on the coming storm systems will be available on Twitter and in my Blog Commentary

Significant Tornado Threat In Southern Manitoba Saturday

A slow moving area of low pressure pushing into our region this weekend will set the stage for the potential of supercell thunderstorms capable of producing dangerous flooding, extremely large hail, damaging winds and possible tornadoes.

 A look at the slow moving low pressure system that is set to roll into Southern Manitoba on saturday with the Severe Thunderstorm coverage risk map.

The main surface low starts to move into our area on Saturday, bringing a warm front up from the Northern plains of North Dakota into Southern Manitoba. 
So what will the atmosphere have available for the Storm's Tomorrow? Looking at Data Provided by Brad from A Weather Moment 

• Moisture: Plentiful. Surface dewpoints will be sitting near 20°C across Southern Manitoba, with 850mb dewpoints pushing up towards 15-17°C. This deep layer of moisture will provide plenty of energy for storms to work with.
• Instability: The major inhibition to storms will be a layer of warm air at 700mb. Temperatures will climb to 10-13°C at 700mb on Saturday morning, however cooler air will push in later in the afternoon, helping destabilize the mid-levels. LI values of -8 to -11, combined with CAPE values anywhere from 2500 J/kg to 5500 J/kg are evidence of an extremely unstable atmosphere.
• Shear: With a decent upper-level jet pushing in through the day, most areas across southwest and south-central Manitoba will see bulk shear values increase to 30-40kt by evening.
• Trigger: A warm front draped across Southern Manitoba will be strong enough to initiate convection in the mid-to-late afternoon as the cap begins to erode.

Overall models are having a hard time deciding on the speed of this system, but they agree that it has the potential to produce dangerous supercell thunderstorms capable of producing tornadoes. The greatest difficulty is predicting where they will form, current indications are that the greatest threat for tornadoes will likely occur in a the region from North of grand Forks towards and north of the Canadian Border. This would likely include the Red river Valley and into Winnipeg and North. Although if this turns out to be different SW Manitoba might be under the gun, for tornadoes. So overall here is the Risk Map for Saturday:

The Latest Storm Prediction Centre Severe Weather Outlook, areas hatched in red indicates the best chance for severe thunderstorms.

                                                                                                                                         According to Brad "large MCS will likely develop as the whole system lifts northwards overnight, which will continue to provide a severe weather threat in the form of strong winds and large hail. It will push through the RRV by Sunday morning. We may see the threat for another round of thunderstorms on Sunday afternoon, however they are not expected to be severe. Things will finally cool off on Monday as the main upper low moves through and draws in cooler, dryer air from the west.

More Showers and Thunderstorms on the way for Parts of southern Manitoba

While temperatures will soar to near 30 degrees today, the Red River Valley should be prepared for showers and possible thunderstorms to develop by mid towards late afternoon. This will result from a low pressure system that will move into the area and tap into heat and moisture.

Temperature outlook from the weathernetwork

According to A Weather Moment " A strong capping inversion will be in place over the Red River Valley, heat and moisture being pumped northwards will be trapped at the surface, allowing our temperature to soar to the 30°C mark and pooling moisture that will push our dewpoints up to around 15°C". Today will will be a glorious day throughout the morning and early afternoon. Although conditions will start to breakdown by late afternoon as a surface low lifts north into Southern Manitoba.

According to A Weather Moment "The surface low will travel along a pre-existing surface trough and be supported by a shortwave ejecting northeastwards from the main upper trough, still anchored through Montana and Wyoming. As well With the heat trapped near the surface, the Lifted Index is expected to drop to the -2 to -8 values, with the lowest values running along a line from Gretna, MB to Bisset, MB and increasing to the southeast of that line. The heat combined with ample moisture is also expected to produce high CAPE values generally from 2000 to 3000J/kg. Increasing mid-level lapse rates with the approach of the shortwave will provide enough destabilization to erode the capping inversion through the afternoon and allow showers and thunderstorms to develop along and ahead of the warm front, initially concentrated near the triple point of the system. The showers and thunderstorms will expand in coverage as the evening progresses and the low-level jet intensifies." 

The severe weather threat is well defined says brad from A Weather Moment,"as EHI values rise to between 1.5-2.0 by late afternoon, which when combined with the presence of 30-35kt of bulk shear certainly presents the chance for supercell storms to develop. A few things hamper my excitement, though:

• Bulk shear isn’t really all that impressive; the really good shear moves through Western Manitoba through the day today, lifting northwards into the Interlake. The shear diminishes to the SE and isn’t particularly strong where the greatest CAPE is. When it comes down to it, it’s likely that we’ll end up with marginally strong shear on top of marginally high CAPE this afternoon, with the most favorable conditions missing each other.
• CAPE values may be too high. The NAM & GFS have been forecasting dewpoints slightly higher than have materialized. The amount of energy for storms to work with is going to be heavily dependant on the dewpoints that develop this afternoon, and if they don’t make it as high as forecast then we’ll be seeing weaker storms.
• Too many storms. With so many marginally severe features, we may see quite a few showers and thunderstorms develop this afternoon as the cap erodes. If too many fire off, then it will be difficult for any one storm to oragnize itself into anything that poses a severe weather threat."

All that being said, a potential for severe weather does exist today across south-central and southeast Manitoba. The main threats should severe weather develop will be hail and/or the possibility of a tornado."

Severe Weather threat as highlighted by Brad

Overall everyone should be on the lookout for severe weather and or Storms, as well updates will be available on Twitter.

String of deadly Tornadoes hits the United States

Setup for the tornado outbreak of March 2nd,2012

_{As I mentioned back on Friday morning there was going to be a possible tornado outbreak for today, that's exactly what happened. Through Friday a total of fifteen states were hammered by the worst Tornado Outbreak in Years! The day started off fairly vigorous for people in the states, at 6am a squall line of thunderstorms along the cold front marched eastward through the plains bringing intense frequent lightning, hail to the size of golf balls at times, and high winds in excess of 60+ miles/hr or 96 km/hr. That same line moved eastward with the cold front throughout the morning into the eastern states, where it entered the warm moist gulf air mass and high shear environment. As a result it transformed into a line of tornado producing super cells at 9am.That is when the first few Tornadoes started. At around 9 am a Tornado hit North of Huntsville Alabama. The Tornado Apparently severely damaged houses and heavily damaged a high school.}

(Left: Truck on it's side in front of a gas station, in Henryville,IN)

_{Later On in the afternoon a long lived Tornadic Supercell Formed just north of the Ohio river dropping tornadoes in communities of southern Indiana including Marysville and Henryville.The Community of 1000 people in Marysville was completely destroyed, the nearby town of henrysville was also destroyed. One resident describes the scene like a war zone! "Cars were thrown across the road,street signs were down, homes were decimated, the metal in the ground, the railings for the roads were completely ripped out of the ground and some were in cars. As well Semis and Trucks were overturned." Many other communities were affected by the tornadoes in Indiana during the afternoon hours.}

Radar Image of the tornado entering West Liberty,Kentucky

Tornado Damage in West Liberty,Kentucky

_{Once the evening hours came around (approx 5pm CDT) another Tornado extensively damaged the downtown region of West Liberty,Kentucky.This Time it was affected by an EF3 Tornado, with winds in excess of 220 km/h.}

 

 Data Courtesy of Accuweather.Weathermatrix.com

Satellite Image of the tornado outbreak as it was occurring

Tornado Stats

Death Toll: 31 and rising*
States Affected: 15*
Total Warnings: 660
Area Covered: 38,000 sq. mi.
Tornado Warnings: 281
Severe Thunderstorm: 356
Lightning Strikes: 156,399
Total Spotter Rpts: 809
Tornado Reports: 95
Funnel Cloud: 51*
Wind Reports: 246
Hail Reports: 417

Overall It was a significant Tornado Outbreak, one we will not forget for a long time! there were many stories of survival, courage, and miracles during the recovery efforts, yet they still continue. I can guarantee you those stories will be featured on the news over the next few days. To find out how you can help please visit: http://www.redcross.org/contactus/