Showing posts from October, 2017

Hurricane Nate Threatens New Orleans

The image below, a forecast for October 8, 2017, run on October 7, shows Hurricane Nate near New Orleans, with winds as fast as 83 mph or 134 km/h (at 850 mb) and up to 5.33 in or 135.4 mm (3-hour precipitation accumulation) of rain (at the green circle). Early forecast also showed as much as 6.1 in or 154.9 mm of rain (3-hour precipitation accumulation) hitting the Mississippi coast. The NOAA image below also shows the track over North America as forecast over the next few days. Nate, the fourth major storm to strike the United States in less than two months, killed at least 30 people in Central America before entering the warm waters of the Gulf and bearing down on the U.S. South ( Reuters report ). One of the biggest dangers is storm surge flooding, as illustrated by above image and the  tweet below. 7-11 ft storm surge on the MS Gulf Coast and open water coast in SE LA from #Nate . I’m 6ft 6 in. This pole is 11 ft. Some perspective. — Ken Graham (@wx4

The Arctic is Changing the Jet Stream - Why This Is Important

By Sam Carana, with contributions by Jennifer Francis Global warming is increasing the strength of hurricanes. A warmer atmosphere holds more water vapor and sea surface temperatures are rising. Both of these changes strengthen hurricanes. Steering winds may also be changing, causing unusual hurricane tracks such as Sandy's left turn into the mid-Atlantic seaboard and Harvey's stagnation over Houston. Is rapid Arctic warming playing a role? Jennifer Francis has long been warning that global warming is increasing the likelihood of wavier jet stream patterns and more frequent blocking events, both of which have been observed. The Arctic is warming more rapidly than the rest of the world. The narrowing temperature difference between the Arctic and lower latitudes is weakening the speed at which the jet stream circumnavigates Earth and may be making the jet stream more wavy. In a 2012 study, Jennifer Francis and Stephen Vavrus warned that this makes atmospheric blocking events in t