North Dakota Sees First Significant Tornado Day this Year

Last Saturday, on June 27th, North Dakota saw its first tornado outbreak of the year where 19 twisters touched down across the state.

A surface trough moving across the region associated with an upper level wave was the focus for severe weather across the region last Saturday. Plenty of instability was in place – MLCAPEs in the order of over 2000J/kg and sufficient shear (around 40 knots) was enough to support supercells in the region under the northwest flow. The first supercell in the region fired on the Manitoba side of the border and brought very large hail the size of tennis balls and strong winds to Roseisle and surrounding communities, such as Miami, MB. As the supercell drifted towards the south southeast it crossed the border into North Dakota near Walhalla, and held together quite well. A damage survey conducted by NWS Grand Forks it was found that several weak tornadoes were spawned out this supercell before it encountered a cluster of thunderstorms and weakened. Later on in the day several other tornadic supercells fired along the surface trough to the south of the initial supercell that was in northern North Dakota and produced more tornadoes.

After conducting a damage survey of the area, NWS Grand Forks concluded that 19 tornadoes touched down on June 27th, 2015. (Source: NWS Grand Forks)
After conducting a damage survey of the area, NWS Grand Forks concluded that 19 tornadoes touched down on June 27th, 2015. (Source: NWS Grand Forks)

After it was all said and done, it was concluded that the strongest tornado of all, a cone tornado, was one that touched down near Grand Forks and was of EF-2 strength (winds between 177km/h and 217km/h). The other tornadoes reported were mostly of rope type and weaker; of EF-0 to EF-1 strength. Thankfully the NWS Grand Forks was quick on the warnings and did a good job alerting the public of a nearby tornado – no injuries or deaths were reported with any of the 19 tornadoes.

One of the rope tornadoes in ND observed near Pisek. (Source: Matt D)
One of the rope tornadoes in ND observed near Pisek. (Source: Matt D)

In other weather news this week, the west Pacific has been quite active typhoon-wise as three tropical storms are currently active, and of those one is expected to strengthen significantly by the beginning of next week, possibly to super typhoon status.

Eastern Pacific Active Season Starts Early

The Eastern Pacific hurricane season is off to a record breaking start this year as hurricane Blanca formed south of the Baja Peninsula last week and meandered north towards it. Blanca finally made landfall early this past week on the Baja Peninsula; this is the earliest in the season that a hurricane has ever made landfall on the peninsula since records began.

Hurricane Blanca initially struggled with too much shear tearing the storm apart while it was organizing about 1000km southeast of the Baja Peninsula, but as it slowly drifted north, the environment became more favourable for development.  The storm quickly formed an eyewall and became a category four hurricane. After an eyewall replacement and cooler waters churned up from the stormy seas, Blanca weakened to a category one. However, not too long after, it restrengthened to a category four. By the time the hurricane approached the Baja Peninsula it had encountered cooler waters and slowly weakened to a tropical storm.

Hurricane Blanca with a well defined eye on June 3rd.  (Source: NOAA)
Hurricane Blanca with a well defined eye on June 3rd. (Source: NOAA)

Although the storm was only classified as a tropical storm when it made landfall, bringing winds of 75km/h, the outages it caused were fairly significant. It caused 105,000 of the peninsula to lose power, and brought storm surges of about 5m to areas near the resort town of Puerto Vallarta, on the eastern shores of Mexico. In addition to that, the storm brought significant rainfall in the order of 75-150mm across the Baja Peninsula.  A few days ago, the storm transitioned into a depression over the southwest US and produced some rains over the drought-stricken state of California.

Yet another storm has formed this past week southwest of the Baja Peninsula – hurricane Carlos. Although this one did not strengthen to a category four like Blanca did, there is a chance that it brings another significant rainfall to the Baja Peninsula as a tropical storm by mid-week next week. The storm season for the East Pacific officially starts May 15th.

India Faced with Intense Heat Wave

A heat wave has taken hold across much of India in the past few weeks and will continue to do so before monsoon season arrives next week.

A weak ridge aloft has allowed extreme heat to build into the region while tropical dewpoints over 25°C remain in place. With these temperatures and dewpoints combined, several locations in Eastern India, like Bhubneshwar, have seen humidex values above 55°C – signifying heat stroke is probable with any time spent outside. Not only that, but overnight lows stayed well above 30°C for several days in some regions, providing no relief to the residents. Additionaly, dust storms have been taking place across the drought stricken areas in the north. In Rajasthan, a dust storm killed seven people two weeks ago. Heat waves can be crushing to developing countries, such as India, resulting in exponentially more deaths and damages compared to first world countries as residents have limited access to clean drinking water to hydrate themselves, never mind air conditioned houses.

Asphalt was literally melting away on New Delhi roads  due to high temperatures this week. (Source: Rappler)
Asphalt was literally melting away on New Delhi roads due to high temperatures this week. (Source: Rappler)

Over half of the deaths (1,334 deaths) associated with the heatwave came from the Andhra Pradesh province, while the most recent overall death tally reached 1,826 people. This, according to Jeff Masters of Weather Underground,  is the fifth deadliest heat wave in world history since record keeping began and second deadliest to India (deadliest was 1998). Water shortages were the main problem leading to dehydration and heat stroke; to combat this, the country brought in water tankers and aid to over 4,000 towns in the hardest hit areas.

Help might be on the way however. The seasonal rains that India experiences, called monsoonal rains, are advancing northwestward towards the heat-stricken provinces. These will not only bring much needed moisture to the region, but also allow temperatures to drop well below what India has been experiencing past few weeks. The few weeks preceding the monsoonal season typically do bring heat waves and dry weather to India, but some years are harsher and last longer than others.

Southern Plains States Faced with Serious Flooding

The western troughing pattern, with occasional cut-off lows that have been hanging around the west coast have done good work in eliminating the drought that was entrenched in the Southern Plains past few years. The copious amounts of rain that have fallen in the last month or so has not only taken out a large part of the drought, but caused serious flooding issues in the region. This heavy rainfall stemmed from several storm types; rounds of trailing severe thunderstorms, large areas of stratiform rain as well as slow moving storms the would drop significant amounts of rain. These have all occurred in the Oklahoma/north Texas region since the end of April.

The flooding is not only wreaking havoc on farmers in the area, whose crops are struggling due to all the rain, but also the general population as several major highways in the region have been washed out and forced to close. Lake Eufalufa, one of Oklahoma’s major lakes is currently 14 feet above normal, causing many campsites nearby to be shut down. In Wichita Falls, Texas, neighbourhoods in low-lying areas were forced to evacuate ahead of the next system – the city announced they would be cutting power at all these neighbourhoods to prevent electrical fires. In Norman, Oklahoma, heavy rains from trailing storms turned parts of its Main Street into a fast flowing river this past week. It’s unclear how many people have been affected since the beginning of May throughout the south but two people are known to have died in the floods. The good news is the extreme drought, which covered 29% of the region last year, is now down to 0%.

Past 30-day rainfall in Oklahoma shows significant rainfall across much of the state, with a 495mm tally in Norman.
Past 30-day rainfall in Oklahoma shows significant rainfall across much of the state, with a 495mm tally in Norman.

More rain is in the forecast for most of these regions this weekend – with possibly another significant rainfall in the works. In some of the hardest hit areas, such as central Oklahoma, more than 75 additional millimetres could fall this weekend; flood watches are already in effect and meteorologists are urging residents to limit travel.