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.

Elsewhere in Weather News: May 17th, 2014

Wildfires Torch California, Helped by Strong Winds and Drought

This past week several wildfires have been burning out of control in San Diego County, just north of San Diego. It is not known whether any of the fires were started intentionally or not, however, the weather has played a significant role in hampering firefighting efforts. As of Friday evening there were four wildfires burning in the county which were all over 1,000 acres in size, and only one of these four was above 25% contained. There are two main points to note of as to why weather has played such a significant role in fueling the fires.

A large pyrocumulus cloud could be seen on Wednesday from San Diego looking towards the Cocos San Marcos fire. (Source: Mashable/Kent Horner)
A large pyrocumulus cloud could be seen on Wednesday from San Diego looking towards the Cocos San Marcos fire. (Source: Mashable/Kent Horner)

The Santa Ana Winds are the first to have a big impact on wildfires currently burning out of control in Southern California. These winds occur when air blows towards the Pacific Ocean from the mountain ranges to the east. As the air descends the mountain sides it warms and its relative humidity decreases causing for hot and dry winds. This past week, relative humidity as low as 3% was observed by stations in southern California, coupled with winds of 50km/h, this produced prime wildfire conditions. The second reason as to why the wildfires have been difficult to contain is the current drought situation in the region. A large ridge of high pressure has been persistent over the west coast for most of this past winter and part of this spring, making precipitation difficult to come by. The drought index currently indicates that an extreme drought (second highest tier) is occurring in the region where the fires are burning. In turn, the wildfires have little trouble spreading to moisture-starved vegetation and dried out brush.

This weekend offers a mixed-bag to firefighters. Strong winds and scorching temperatures will persist during the day, but winds will now be out of the west causing for slightly moister air coming onshore from the Pacific. Regardless, the Storm Prediction Center maintains an “elevated” fire risk for this weekend.

Elsewhere in Weather News: March 22nd, 2014

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: January 18th, 2014

Severe Californian Drought

A severe drought has settled into a good part of the state of California and is starting to be of concern to residents as numerous brush fires have been sparking up this past week. A strong upper level ridge which has persisted over California for a good part of the past month has diverted all low pressure systems well north into BC. With this, a large area of California has been left dry and drought conditions have worsened significantly in the past month. The Drought Index shows that levels have reached extreme for over 50% of California, including Los Angeles. Los Angeles, on average, receives 80mm of rain during the month of January but they have yet to record any rainfall this January. To make matters worse, no pattern changes are in the forecast; the ridge is expected to remain in place at least until the end of January. Models show no precipitation in the foreseeable future for the southern half of California, which means that Los Angeles has a possibility of going the whole month of January without any precipitation.


Drought Index for the West Coast, ranging from abnormally dry (yellow) to exceptional (dark red). A good chunk of California is under extreme (red). (Source: USDA)
Drought Index for the West Coast, ranging from abnormally dry (yellow) to exceptional (dark red). A good chunk of California is under extreme (red). (Source: USDA)

The snow pack in the Sierras has shown telltale signs of drought with only having 20% of the average snow water equivalents for this time (about 25mm of SWE). In this tweet sent out by the Boise NWS a drastic comparison in the snow pack can be seen over the Sierras. If no significant precipitation arrives before spring, California will be setting itself into a long-term drought.

A drought emergency had been issued for California, asking residents to limit their use of water. Bushfires have been flaring up due to the dry conditions, including the Glendora fire which is a fire that started on Thursday and has already burned 1,700 acres east of Los Angeles. Santa Ana winds gusting to 35km/h have been fueling the fire and will continue to do so until tomorrow, making it difficult for crews. Relative humidity in the area has a chance to dip as low as 5% during the day – making for ideal wildfire conditions. This has prompted the National Weather Service to issue a red flag warning east and northeast of Los Angeles.