Lab – Extreme Spring Rainfall

The recent opening of what has been described as an atmospheric river California has caused heavy rainfall over January and the preceding months. Combined with a strong Pacific storm, the atmospheric river led to record high amounts of rainfall that has not been witnessed in the state for close to over a century. The moisture laden winds from the Pacific Ocean were pushed inland leading to extremely high amounts of rainfall that soaked large swathes of land especially in the Coastal America. The severe rainfall marked by historically high daily recordings came in the backdrop of another severe weather system of historic proportions: severe drought like never witnessed in the state before. The drought devastated California estate for several months. Its ripple effects where even felt in the neighboring states due to the overlapping of climatic conditions.

The interchange between two opposite ends of two weather patterns with historical figures brought closer to home a weather phenomenon commonly ignored by many Americans as foreign weather system confined to geographical scholarly endeavors. The severe polar ends of weather patterns are a manifestation of the El Nino weather system. It is a weather pattern that has for some years witnessed in other continents including Africa and Asia. However, the rainfall, like in the case of the devastating drought, it was not confined to California alone as neighboring states also recording historically high amounts of rainfall.

The strong winds moving inland from the Pacific Ocean to the mainland United States led to flashfloods. The resulting severe flashfloods sustained over weeks led to damage to the numerous levees that directed the storm waters and preventing them from causing severe damage to properties or loss of lives. However, the floods were too strong for the infrastructure designed to contain them. Up to dozens people were reported dead while properties worth billions of dollars including bridges and farm produce especially in the rural areas were damaged. Vital infrastructures such as electricity power lines, roads and bridges were swept away by the flashfloods. Water and sewer lines were also affected by deluge that pounded the area for weeks without. This contaminated the water systems in the area. Farmers in rural areas were left counting losses as their crops and animals were swept away by the floods. Hundreds of families were left homeless and had to seek alternative shelter. It is estimated that the cost of restoring some level of normalcy in the area will cost over $50 billion. The funds will be used to resettle families, reconstruct vital infrastructures and restore vital services to the general public.

The heavy torrents were as a result of a reversal of the Northern American wintertime stationary waves, which affects the mean temperatures in the region. Also known as the Northern American dipole, the phenomenon weakened over the winter leading to a reduction in mean temperature difference between eastern and western U.S which are colder and warmer, respectively. The colder eastern U.S became warmer while the warmer western region became significantly cold. This allowed the moisture laden winds to sweep through the coastal regions in California and other regions such as Nevada. Moreover, the temperature differential allowed the moisture laden atmospheric river to sweep in from Hawaii. The atmospheric river moved slowly across California with its epicenter primarily in Northern California, which were the most affected as inches upon inches of rain continued to pummel the region.

Signs of massive flooding as a result of the torrential rains were already visible in early January with the authorities in various regions in California and Nevada issuing an evacuation order. The heavy rains continued to pummel the region in record amounts with residents of various areas such as Los Angeles going for days without electricity as torrential rains accompanied by strong winds and flash floods knocked out power lines and other utility lines. Several trees were also knocked over and consequently took out the utility lines. In some areas such as Maxwell, Oroville and Santa Cruz among others, residents had to be evacuated to higher and dry land where emergency tents and temporary settlements were setup for them. The rescue mission led by law enforcement agencies also saw several people lifted out to safety using helicopters. Residents living down Oroville Dam and various rivers in region had to be evacuated as the storm waters not only breached and overpowered the levees but also the spillways on dams. The down river areas are at a high risk of flooding the rains continued to pound the region in the February.

Even as locals partner with emergency services and law enforcement agencies to mitigate the effects of the flashfloods including reinforcing the quickly deteriorating levees, it should not be lost to the authorities and residents that these severely heavy rainfalls are manifestations of a pending danger of climate change that scientists had warned off several decades ago. As the global atmosphere gradually becomes warmer, there is a reversal of climatic conditions. The reversal of the Northern American dipole is a manifestation of climate. The eastern stationary waves became warmer instead of colder. The resulting warm currents laden with moisture swept across the land leaving behind destruction as a result of heavy rainfall and strong winds. Therefore, instead of the winter snow heavy rains pummeled the region leaving its wake a string of deaths and destruction. In the end, the region is being tossed from one extreme end to another by Mother Nature: record drought system followed by historically high amounts of rainfall.

As the residents return to their homes to count their losses and find the motivation to pick up their lives, the authorities are now fully aware of their inadequacies and strengths when it comes to dealing with such natural disasters. Once again forces of nature have left the authorities with a bill to settle: over $50 billion in reconstruction cost. It exposed the frailties of the levees designed several years ago to withstand mild floods and snow. Additionally, several lives were lost while the rural farmers are counting their losses too as most of their crops were swept away. The weather patterns are increasingly becoming unpredictable and devastating. With the occurrence and movement of such atmospheric rains and laden winds significantly challenging to predict with pinpoint accuracy, the future seems portentous. How devastating will the next storm or drought be? The lack of definite answer to this question is perturbing. It portends a danger unknown but whose devastating capabilities have so far manifested to the residents of Northern California and even Nevada. No one knows with certainty how severe the next reversal of the dipole will be.