Category: Posts EN

Rosa Targets Baja California and the American Southwest Early Next Week!

Written by Team Morecast

 

Hurricane Rosa underwent rapid intensification early today and is now a category four cyclone. Rosa is moving slowly west and will encounter much cooler sea surface temperatures in the next few days (see map below), so weakening is likely. However, Rosa will also be speeding up and turning north, then northeast. Rosa will threaten portions of northwest Mexico and the American Southwest later this weekend into early next week.

 

 

Most of the models suggest Rosa will make an initial landfall along the northern Baja Californian coast. By then, Rosa will have weakened significantly thanks to much cooler water temperatures. However, increasing forward speed may carry it fast enough into the Desert Southwest that Rosa will retain some gusty wind potential, especially in the higher terrain near and east of the track of the circulation.

 

 

The most significant hazard, however, will likely be heavy, flooding rainfall over a region unaccustomed to the kinds of amounts in the forecast. Where the rain falls will depend on the exact track of this small but powerful storm. Most models carry the storm through central Arizona. In this corridor, expect widespread amounts of 1.5-3 inches (38-75 mm) in 12 hours or less. Localized amounts of 4-5 inches (100-125 mm) are likely. That kind of rainfall will easily overwhelm the local drainage capacity. Significant flooding will be the result!

 

Trami Weakening and Crawling, But Threat to Japan Looms This Weekend!

Written by Team Morecast

 

Typhoon Trami peaked at Category Five intensity on Tuesday. Since then, Trami has been moving very slowly, allowing ocean waters to cool underneath the storm. This has cut off the supply of warm ocean moisture that typically fuels cyclones. Trami has weakened back to Category Three status, though it can still boast sustained winds to 90 knots (167 kph). Models indicate the storm could intensify a bit as it picks up speed and takes aim for Japan late this weekend into early next week.

 

 

Trami is currently drifting slowly north under the influence of weak steering winds. An approaching trough will eventually pick Trami up as the cyclone enters the East China Sea late this week. A turn to the northeast looks likely which would cause the cyclone to rake many of the Japanese home islands. The interaction with the trough would mean heavy rains breaking out in the south as early as Friday, persisting through Monday. Later next week, the typhoon will transition to be a large and powerful extratropical cyclone over the northwest Pacific.

 

 

While forward motion is so slow, conditions will not be favorable for strengthening. However, there will be a window of opportunity for some strengthening as the cyclone starts to accelerate. Trami will be a threat to produce damaging winds and a minor to moderate storm surge, especially in southern Japan. However, the more widespread threat will be flooding rainfall. Most of Japan will see amounts of at least 75-150 mm. Locations in the central and south will see totals commonly 150-300 mm, with some spots seeing totals of 400-450 mm! Serious flash flooding is likely.

Flooding from Hurricane Florence Yet To Subside in Some Areas

Written by Team Morecast

 

The last raindrops from deadly Hurricane Florence fell in the Carolinas more than a week ago. However, the massive amount of water the storm dropped is still moving through the region’s river systems. In fact, one of the larger rivers in the region, the Waccamaw, has yet to crest. Record flooding is ongoing, adding to a damage toll that will eventually put Florence among the top ten costliest cyclones of all time.

 

 

In the NASA satellite image above, you can see the darker sediments and debris flowing into the Atlantic from rain-swollen rivers. Florence dropped close to three feet of rain in some areas of southern North Carolina and eastern South Carolina. The resultant flooding constitutes the bulk of a price tag that Moody’s Analytics predicts will finish between $38 and 50 billion dollars. Even the bottom end of that range would put Florence at sixth on the all-time list of costliest U.S. tropical cyclones. Florence is also being blamed for 48 deaths in the U.S.

 

 

Flood waters have receded in many of the hard-hit areas of the Carolinas. However, the clean-up of thousands of water-damaged homes and businesses will take months. Many of these swamped structures will have to be totally gutted and rebuilt. However, some of the larger rivers are still absorbing runoff from upstream. The Waccamaw River in eastern South Carolina is still rising as of Tuesday evening (see gauge map above). It’s already two to three feet higher than previous record crests. Major towns like Conway and Georgetown are facing widespread flooding (see tweet link below) that will last through the end of the week at least.

 

 

 

Super Typhoon Trami a Harmless Giant for Now

Written by Team Morecast

 

Super Typhoon Trami became the fourth category five cyclone of the 2018 Western Pacific season on Monday. Forward motion has slowed to westward crawl, however. Steering winds will remain quite weak over the next few days and Trami won’t pose an immediate threat to any major land masses. That could change as we head towards this weekend, however!

 

 

Trami will continue to move through a favorable environment over the next few days. Ocean waters lie beneath the storm with weak vertical wind shear above (see map above). These conditions will ensure that Trami remains a strong typhoon despite the slow storm motion that might otherwise lead to weakening.

 

 

Trami is expected to drift slowly north to northwest through the next couple of days. Later in the week, Trami will move more quickly to the north or northwest as steering currents strengthen. Most models bring the system north into the East China Sea by week’s end. The storm’s track after that is uncertain. There’s a strong possibility it could approach the southern islands of Japan this weekend or early next week. We’ve got several days of monitoring left to do, though, before Trami poses that kind of threat.