Category: Elsewhere in Weather News

Elsewhere in Weather News: September 29th, 2013

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Wutip Forms, Typhoon Usagi Update

This week the Northwest Pacific typhoon season continues to be active as another typhoon – typhoon Wutip – has spun up in the South China Sea and is tracking westward. Although this is good news for the residents of Hong Kong and southern China who have been affected by last week’s typhoon, Vietnam will now have to closely monitor Wutip. As of Friday night Wutip was only a high-end tropical cyclone but is expected to slowly continue to strengthen over the open waters of the South China Sea. It will likely only have enough time to strengthen to a category one typhoon before it makes landfall near the city of Da Nang. Still, residents of Vietnam will have to watch for storm surge that could wreak havoc in low lying coastal areas as well as flooding; much rain will be associated with Wutip. It’s expected that Wutip will make landfall Sunday night.

Wutip

Infrared enhanced image of Wutip on Friday night. A bit of dry air to the south-east of it’s center but very cold tops (white) near it’s center as it was attempting to organize itself. (Source: CIMSS)

The storm talked about in last week’s EIWN, typhoon Usagi, has caused significant damage to coastal areas of China, in the Guangdong province. In total, 25 people have died in China due to landslides triggered by the heavy rains and storm surge. Search and rescue teams are still looking for survivors in the mud though, and cleanup efforts are now underway. Usagi made landfall 140km to the north-west of Hong Kong; there it brought with it sustained winds of 175km/h which gusted to over 200km/h. In Hong Kong over 200 flights had to be cancelled. Although once a powerful super typhoon, Usagi is no more as it moved over China’s mainland and fell apart this past week.

Elsewhere in Weather News: September 21st, 2013

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Super Typhoon Usagi Takes Aim at Hong Kong

The strongest typhoon of the year up to date has formed in the Pacific and is taking aim at Hong Kong. Super typhoon Usagi is currently located in the Luzon Strait between Taiwan and the Philippines and is moving in a west north-westerly fashion. Thursday and Friday morning, Usagi was packing sustained winds of around 260km/h – considered category five strength. It has since slightly weakened but is still a dangerous category four super typhoon as it eyes (no pun intended) Hong Kong and the southern coast of China.

Usagi

Awesome image of Usagi Thursday afternoon. (Source: Colorado State University/Capital Weather)

This super typhoon is not only a very powerful typhoon but also a very large one; its diameter reaching over 1,000km. A very distinct eye could be seen on satellite as well as more than one eyewall present; it is not as common for a tropical system to have more than one eyewall, though it does happen with storms of category three or higher.

Usagi is expected to make landfall sometime on Sunday along the south China shores. Its impacts remain to be seen though, with seas expected reaching 10 meters in the South China Sea all vessels will have to steer clear or dock. Another concern is the rainfall; already copious amounts of rain have fallen in Taiwan, especially on its east coast where about a meter of rain was not out of the question before the weekend’s end.

In addition to Usagi, a second typhoon is expected to form this weekend behind (to the east) of Usagi, it will be named Pabuk. Although still a ways out, Pabuk has a good chance at becoming a severe typhoon due to the warm sea surface temperatures and low shear in the area. Currently, the models show Pabuk reaching the eastern shores of Japan but then quickly curving back out to sea – this would suggest minimal impacts to Japan.

Elsewhere in Weather News: September 14th, 2013

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Historical Flooding in Colorado

This past week Colorado has been absolutely swamped thanks to moisture streaming up from the Gulf of Mexico, riding up the Rocky Mountains (upslope flow) and then falling as rain. High pressure sliding down from the north in the US Plains as well as an upper-level low to the west drew in the moist air from the southeast. Generally, 850mb dewpoints could be found in the 15°C range and PWAT values around 40mm in Eastern Colorado. Plentiful moisture was in place – a recipe for heavy rains that had the possibility to fall for a long period of time. This became the case for Wednesday evening through Friday morning for Boulder, Colorado and surrounding communities.

850mb moisture transport

Radar with overlay of the 850 moisture transport, notice the vectors all pointing towards the Rockies. Taken Friday 3am. (Source: SPC Mesoanalysis image archive)

As best described by NWS Boulder, flooding of “biblical” proportions took place is continues as of Friday night. Small creeks easily turned into raging rivers that inundated whole towns and mudslides blocked highways, took out buildings. The death toll is already at four but concerns of more as 172 people are still missing and some communities are literally cut off, with no roads leading in or out of town. Interstate 25 had been closed due to water running over it as well as numerous other highways that had simply been washed away.

The average rainfall per year for Boulder, CO is around 525mm, this means that in a few days Boulder got over half its annual rainfall at 310mm. This easily beats out the old record for rainfall in September (243mm), and average of 43mm (this month; 721% above average September rainfall). Interestingly enough, the area which received all this rainfall was under a moderate to extreme drought as per the Drought Index.

Rainfall estimates

Estimated rainfall from KFTG as of Friday 3am. Notice the dark purples/white; areas above 200mm estimates. Map storm total accumulation. (Source: GRLevel3)

It appears as though Boulder might get a break from the rain today as the upper-level low weakens and moves further east though there is still a slight chance for pop-up (non-severe) storms. Tomorrow will likely bring with it more rain for the region, unfortunately.

Elsewhere in Weather News: September 7th, 2013

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Tropical Storm Gabrielle Drenches Parts of Caribbean

The seventh storm of the Atlantic hurricane season spun up this past week, though did not affect the continental United States. The tropical storm, Gabrielle, did not reach hurricane status due to unfavorable conditions for storm development, including shear levels being on the high side. Shortly after it made landfall on Thursday it had been downgraded to tropical depression status. Drenching rains still fell across Puerto Rico, Dominican Republic and the US Virgin Islands thanks to Gabrielle’s southerly flow bringing in copious amounts of moisture (PWAT values approaching 75mm) from the Caribbean Sea.

Gabrielle

Gabrielle shortly after it got downgraded to a tropical depression on Thursday early afternoon. (Source: WUnderground)

As of Friday morning the highest rainfall amounts came out of St. Thomas where 175mm had already fallen. In general anywhere between 100mm to 250mm will have fallen across the region after Gabrielle has moved off to the north in the middle of the Atlantic Ocean. Friday evening the storm had been almost completely torn apart north of Puerto Rico and wasn’t a threat to land anymore. No deaths or injuries have been reported with the storm.

Surprisingly there has not been one hurricane in the Atlantic so far this year and if there continues to be a lack of hurricanes until September 16th, a record for the latest start to a hurricane season (since records began) would be achieved. However, longer range models such as the GFS have been showing tropical development in the Caribbean as well as another wave coming off Africa’s west coast in the near future which will be something to keep an eye on.