
JTWC Track- www.usno.navy.mil
JTWC warning text- www.usno.navy.mil
Typhoon Songda (Category 3 system @ 0900UTC)
Currently Songda sits east off the coast of the Philippines and has begun over the last 6-12 hours turning northward (currently tracking west northwest). The system has begun deeply intensifying, strong convection continues around its core and throughout the entire system, outflow is strong and shear maps indicate that the system lies in a relatively low shear environment, however there is a small area of higher shear to the northeast and the visible sat image show signs of mild shearing, within the next 6-12 hours the system is forecast to continue rapid intensification and be classified as a Cat 4 System with sustained winds of 114kts+ as it continues its northerly movement. Recurve to the north east is forecast to begin in 48 hours or so this will project the system directly over the Ryukyu Islands with the possibility of Cat 4 winds (most likely high Cat 3; 105-113kts). Forecasts and models have not changed significantly over the last 24 hours, the JTWC warning track indicates a sharp curve away from Japan in the Later TAU’s (+96 hours) due to strong westerly’s forecast to arrive at the mid latitudes, should this occur the Japanese mainland would be spared the worst of the system, models still vary on track and intensity, however they remain tightly grouped and most indicate serious land interaction with the Japanese mainland bringing in some cases 60kt+ winds and well over 100mm of rainfall to wide spread areas. As mentioned before JTWC amend their forecast track due to known inaccuracies in the models abilities to forecast recurve scenarios and this is why currently they track the system more eastward of Japan than the models indicate. Looking at the usual analysis material at CIMSS(shear, steering winds, water vapor, ect.) the forecast track and intensity seem to be a very reasonable scenario and there seems little to indicate otherwise particularly in the next 48 hours, after that the system will move north past the Philippines, currently the wind shear profile here seems to be very unfavorable, this may improve in that time, also a system as intense as this can at times make its own conditions(basic explanation) so the unfavorable shear profile further north would not affect the system as greatly and it would be able to maintain a higher intensity much further north than currently forecast(this was seen with Aere, the forecast unfavorable shear never eventuated and hence the system maintained greater intensity further north.) Steering winds short term seem a little unsure but definitely indicate continuing northward movement, this is a good scenario for the Philippines and later on Taiwan, provided the northeasterly change in track occurs. Unfortunately the system seems sure to affect the Ryukyu Is. and Okinawa with intense Cat 3 winds. Typhoon Songda still remains at least 72 hours away from first land interaction with the Japanese mainland(as currently forecast) however it poses a very real and serious threat to Japan, should the JTWC reasoning fail or should a forecast weather condition change ever so slightly for example the driving mid latitude westerly’s that will push the system away from Japan weaken than the Japanese mainland will be very much in the firing line of a very serious weather event. Hopefully this does not eventuate! (Remembering…I am no meteorologist)