06W (Danas) Advisories

...Danas accelerates northward towards Korea...

Center Track Forecast

12 hours: 50 knots; 60 mph; 95 km/h24 hours: 45 knots; 50 mph; 85 km/h36 hours: 40 knots; 45 mph; 75 km/h48 hours: 30 knots; 35 mph; 55 km/h72 hours: 25 knots; 30 mph; 45 km/h (Dissipating)96 hours: 25 knots; 30 mph; 45 km/h (Dissipated)

Advisory 3


1-minute sustained wind: 50 knots; 60 mph; 95 km/hEstimated minimum pressure: 982 mbCurrent position: 29.6N 124.3E

Public Advisory

06W, known as Danas, is currently moving northward at 16 knots, or 30 kilometers per hour, with 1-minute sustained winds of 50 knots, or 95 kilometers per hour. Danas is expected to make landfall in South Korea in approximately 24 hours with winds of 45 knots, or 85 kilometers per hour, then dissipate over the Sea of Japan in approximately 4 days. Danas poses a significant rainfall threat to the southern half of South Korea, including the cities of Busan and Gwangju.

Scientific Discussion

Danas continues to appear disorganized, with a somewhat broken curveband measuring around 5/10 around the center of the cyclone, though this convection is fairly strong. All Dvorak estimates continue to lag behind ASCAT passes; wind barbs of 50 to 55 knots were found in an ASCAT pass from approximately 9 hours ago, while Dvorak estimates range from CI2.5/35 kt to CI3.0/45 kt. However, Hebert-Poteat technique estimates suggest that Danas has winds of 55 knots, more in line with the ASCAT passes, though slightly higher. However, convection has intensified slightly since the previous ASCAT pass, though this convection is forming an elongated half-ring around the center (a potential subtropical sign). Thus, for this advisory, I will balance out ASCAT passes with Hebert-Poteat estimates, and set the wind estimate at 50 knots for this advisory.
The newest model guidance is marked by a very tightly clustered agreement in terms of position throughout forecast hour 96, in which most models expect Danas to dissipate by that forecast hour. Given this, I will follow the general consensus. The intensity forecast is also fairly straightforward; Danas is now entering rapidly decreasing SSTs, which are expected to drop below 26C within the next 12-24 hours, which will cause the storm to weaken, though it still has the opportunity to strengthen slightly more in the next 12 hours.

Forecaster ID

MCK

Advisory Archive

Below is an archive of previous advisories for 06W.

...Danas moving northward and accelerating...

Center Track Forecast

12 hours: 40 knots; 45 mph; 75 km/h24 hours: 45 knots; 50 mph; 85 km/h36 hours: 40 knots; 45 mph; 75 km/h48 hours: 35 knots; 40 mph; 65 km/h72 hours: 30 knots; 35 mph; 55 km/h96 hours: 25 knots; 30 mph; 45 km/h120 hours: 20 knots; 25 mph; 35 km/h

Advisory 2


1-minute sustained wind: 35 knots; 40 mph; 65 km/hEstimated minimum pressure: 989 mbCurrent position: 23.7N 123.3E

Public Advisory

06W, known as Danas, is currently enhancing the monsoonal flow across much of the Philippines due to its large circulation. It is expected to rapidly move north and then eastward into the Sea of Japan and strengthen to a moderate tropical storm, producing wind impacts in Taiwan, Korea, and Japan.

Scientific Discussion

Danas has surprisingly moved northward away from the developing circulation to the west of Luzon Island and is now generating strong convection of its own. This convection is currently being measured as having cloud tops as cool as -82 Celsius, while the circulation to its southwest, now designated Invest 91W, is maintaining extremely cold convection with a particularly potent, but unidirectional cirrus outflow and an unclear low-level circulation that does not appear to be closed. Thus, for this advisory, I will track the original circulation, which is confirmed by ASCAT passes as having winds of 35 knots.
Most models now anticipate that the current circulation of Danas will survive until extratropical transition in the Sea of Japan. In fact, given this clarity, the model guidance is now fairly clustered together, though the GEM remains a particularly slow solution. For now I will mostly follow a blend of the ECMWF and GFS solutions, taking Danas into the Sea of Japan in approximately 60 hours. It should be noted that while sea-surface temperatures are expected to drop below the 26C level within 36 hours, wind shear is expected to decrease to below 20 knots within the next 12. Thus the intensity forecast today calls for strengthening, though I will stay conservative for now.

Forecaster ID

MCK

...06W drifting northward east of Luzon...

Center Track Forecast

12 hours: 35 knots; 40 mph; 65 km/h24 hours: 35 knots; 40 mph; 65 km/h36 hours: 35 knots; 40 mph; 65 km/h48 hours: 25 knots; 30 mph; 45 km/h72 hours: 20 knots; 25 mph; 35 km/h

Advisory 1


1-minute sustained wind: 40 knots; 45 mph; 75 km/hEstimated minimum pressure: 987 mbCurrent position: 18.1N 123.2E

Public Advisory

06W, known as Danas, is currently enhancing the monsoonal flow across much of the Philippines due to its large circulation. It is expected to generally drift northward, though it will likely spawn a new center of circulation to the west of Luzon Island which may prolong wind and rain effects across much of the Philippines until it drifts northward.

Scientific Discussion

Danas continues to maintain its sheared structure as it makes its poleward turn. Evident on satellite imagery is a very defined low-level swirl to the east of Luzon Island now making a northward progression, with numerous thunderstorms with cloud tops below -80C to the west of Luzon Island displaced approximately 100 nautical miles to the west. ASCAT passes reveal peak winds of 40 knots. Buoys and weather stations in Itbayat support the positioning of Danas at this time, however model output from the ECMWF and GFS suggest that another center of circulation is forming underneath the robust convection to the west of Luzon Island; several buoys and some weather stations on the western coast also suggest the formation of this western swirl. Thus, the estimated position of Danas is of a very low-confidence nature.
Given this scenario, the forecast for Danas is a low-confidence forecast as well. For the time-being, I will mostly follow the ECMWF and HWRF track forecast, as these models were the ones that predicted the formation of the western center of circulation the best. The GFS also saw this potential swirl, though not to this degree. However, global models suggest that the two centers of circulation will continue to interact with each other, with the general consensus depicting the eastern circulation taking the headstart to the north, while the western circulation shrinks and follows the initial circulation. With this in mind, the track forecast will follow the eastern circulation only, with tomorrow’s advisory to shift to the western circulation of Danas if applicable. Again, keep in mind, this track forecast is one of a very low confidence, given the confusion in center position.

Forecaster ID

MCK