Author: Matthieu

Matt has been a member of the AWM team since January 2012, writing the weekly feature Elsewhere in Weather News which highlights weather news from across the globe. Matt has lived in Winnipeg all his life and has been a weather enthusiast since a very young age. He is currently completing his B.Sc. in Atmospheric Sciences at the University of Manitoba.

Elsewhere in Weather News: March 22nd, 2014

Matthieu Leave a comment

Below Normal February Temperatures for most of Continental US; Will Return

What seems to be the winter that won’t give up in Southern Manitoba has not only been persistent in the Canadian Prairies, but also a good chunk of the United States. The central and eastern half of the US has been fairly consistent in staying below normal in February thanks to a persistent trough on the east coast and ridge over the west coast. Consequently, a northwest flow in the upper levels of the atmosphere has established itself over the Northern US Plains and Midwest and, as a result, Arctic highs were continuously helped down into the region. Interestingly enough, central North America has been one of the only regions in the world to experience below normal temperatures in February.

Temperature anomalies across the globe for February, notice the below average in Central/Eastern US, contrasted by the much above normal just to the east, over the ocean. This is caused by persistent troughing on the East Coast. (Source: NOAA)
Temperature anomalies across the globe for February, notice the below average in Central/Eastern US, contrasted by the much above normal just to the east, over the ocean. This is caused by persistent troughing on the East Coast. (Source: NOAA)

The pattern, which has not shifted around much this winter, has caused extremes to occur not only temperature-wise but also precipitation wise. The problem is that with the ridge staying put over the area systems have trouble making their way into the region and instead diverted further north. California continues to experience severe to exceptional drought – the highest level of drought, as per the US Drought Monitor. Consequences might not be immediate but could spell trouble once the wildfire season rolls around, and when water reserves literally start to run dry in the state. Currently, about 60% of the state is considered to have an above average risk for wildfires due to the drought, according to NICC.

Sunday night into early next week yet another blast of Arctic air is expected to infiltrate across a good chunk of the United States. In addition to this cold blast, models are showing a potent Nor’easter Tuesday-Wednesday next week blasting through the Northeast US and Atlantic Canada which could drop significant amounts of snow. However, there is a glimmer of hope for the central United States as most models are in agreement that temperatures late next week into next weekend will be either bounce back to normal or slightly above normal.

500mb northwest flow returns to the region this week, shown by the NAM here, on Tuesday morning. (Source: Twisterdata)
Northwest flow returns to the region this week, shown by the NAM here, on Tuesday morning. (Source: Twisterdata)

Elsewhere in Weather News: March 15th, 2014

Matthieu Leave a comment

Cyclone Lusi Heads towards New Zealand; Otherwise a Calm Week

The weather this week has been fairly uneventful but the most significant event has been the three tropical storms that churned simultaneously off Australia’s north and east coast earlier this week. The strongest of the three storms, Cyclone Lusi, was of category three at its strongest point when it moved over the Island of Vanuatu. Vanuatu is an Island on the eastern side of the Coral Sea, near New Caledonia. Flooding was the biggest of the resident’s worries as the cyclone was fairly slow moving; affecting the island from Monday through Wednesday. Of course, strong winds were also problematic as many houses on the island are not built to withstand category three cyclone winds (120km/h). Long-term damage could also be concerning – crops destroyed and freshwater contaminated by flooding waters. Nearly 40,000 people living on the island were affected and about 100 people were evacuated from low-lying areas. Unfortunately, six people perished from trees falling on houses and fast currents associated with the floodwaters.

Cyclone Lusi as seen by NASA's Aqua satellite on March 12th, after the cyclone had passed over the northern islands of Vanuatu. (Source: NASA)
Cyclone Lusi as seen by NASA’s Aqua satellite on March 12th, after the cyclone had passed over the northern islands of Vanuatu. (Source: NASA)

The cyclone continued its trek southwards towards New Zealand where it is expected to make landfall this morning. As it moved south the cyclone encountered colder waters causing it to weaken significantly and start its transition to an extra-tropical storm. On Friday evening the cyclone still packed somewhat of a punch as it affected the northern island of New Zealand; about 7,200 people were reported to not have power and residents were urged to stay inside. New Zealand averages about one tropical storm per year.

Elsewhere in weather news, weather has remained relatively quiet across the globe, apart for severe thunderstorms affecting Argentina and Australia.

Elsewhere in Weather News: March 8th, 2014

Matthieu Leave a comment

Cyclone Takes Aim at Northern Queensland

On Thursday, March 7th an area of convection appeared off the northern coast of Australia in the Arafura Sea, associated with a weak tropical disturbance. Since then the convection has remained nearly stationary due to steering winds being fairly weak but not much organization has occurred. However, the disturbed area is expected to organize quickly today into tomorrow as it drifts slightly to the southeast where shear values are low and sea surface temperatures are very warm; 30-31°C. By Sunday evening it is expected that Gillian become a category two cyclone, just off the northern coast of Queensland.

Infrared satellite image of Gillian looking rather disorganized, but with some deep convection on Friday evening. (Source: CIMSS)
Infrared satellite image of Gillian looking rather disorganized, but with some deep convection on Friday evening. (Source: CIMSS)

The Australian Bureau of Meteorology (BoM) warns that winds could approach 150km/h in areas closest to where it makes landfall. Shoreline areas are most at risk along the peninsula due to the storm surge and large waves. Flooding/flash flooding is also expected as areas along the coast have received around 850mm in February; over double their average rainfall for that month. Another 250-400mm could fall in the region due to Gillian. It is expected that Gillian linger through the beginning of next week and die out as it continues south over land.

Queensland's rainfall for the past 30 days, note the area of 800+mm, this is where Gillian is headed. (Source:BoM)
Queensland’s rainfall for the past 30 days, note the area of 800+mm, this is where Gillian is headed. (Source:BoM)

Interestingly enough a second, weaker, cyclone is spinning off the east coast of Queensland and is expected to make landfall at about the same time that Gillian does as a strong category one. Both cyclones are to watch Sunday into the beginning of next week as they pose a threat to the northern and eastern areas of Queensland. The Australian cyclone season begins November 1st and ends April 30th and on average they see about ten cyclones per year.

Elsewhere in Weather News: March 1st, 2014

Matthieu Leave a comment

Australian Town Sees Flooding Rains

The town of Dajarra, a small Australian town in the northwestern part of Queensland, has faced flooding problems that started mid-week and worsened Thursday. The flooding was associated with a surface trough of low pressure that stayed nearly stationary for over 24 hours and sparked slow moving convection. General reports of 60-80mm in the region were reported but some localized amounts reached as high as 150mm. In addition, the region has been drought-stricken in the past few months which makes it tougher for water to infiltrate soils and easier to runoff.

Wills River overflows its banks in Dajarra. (Source: ABC)
Wills River overflows its banks in Dajarra. (Source: ABC)

The result of all this rain was that creeks overflowed their banks and quickly turned into raging rivers. Most residents were evacuated as homes were threatened or were inundated by the floodwaters. Some workers from the railway were also stranded but have since been saved from the waters. The town is still cut off due to floodwaters as of Friday evening.

Dajarra’s average rainfall for the whole month of February is 100mm but they have received over 125% of this in the past week. It appears as though the surface trough will linger until the end of this weekend and continue to bring unsettled weather. This event comes two weeks after the flooding that occurred in Adelaide, South Australia, which wreaked havoc on the city. In one day 73mm of rain was dumped on Adelaide making it the most rain the city had received on a single day in February since 1969.