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Latest forecast track(note moved northward again)- www.usno.navy.mil
Latest warning text-http://www.usno.navy.mil/NOOC/nmfc-ph/RSS/jtwc/warnings/wp0411web.txt
Super Typhoon Songda (Cat 5 @ 0600UTC)
Songda has increasingly intensified over the last 24 hours due to favorable conditions, a low shear environment exists well around the system, a defined eye on msat images indicate this as does the shear analysis @CIMSS. Water vapor conditions remain favorable also, JTWC notes the restricted Pole ward outflow, this may indeed be the only influence that will prevent the system from reaching a strong category 5(Super Typhoon), currently projected to only just make a CAT 5 system with sustained winds of 135kts gusts to 165kts. The pole ward outflow does not look like having the ability to increase with a relatively unfavorable shear profile to the north a head of strong westerly winds, the system however may be able to overcome this with further northward movement but is not progged to. The strong mid-latitude westerly’s blowing from mainland China are the biggest influence on the end result of this system, should they be weaker than forecast or should the system manage to push the interaction zone further northward then it would be a more favorable environment for direct land interaction with the Japanese mainland with higher intensity. Currently the westerly’s appear to lie just north of Okinawa @ ~30kts. Steering wind charts @ CIMSS indicate continued northward movement, model consensus to +36 hours continues to be represented by the JTWC track map, JTWC again mention the use of corrections because of known inaccuracies for their track in later TAU’s +36 hours, models currently predict a tight but varied forecast, their tracks and intensities vary slightly but all models that I have checked indicate land interaction with Japan predominately with the southern tip at least but most indicate a widespread crossing of the mainland. Wind intensity is consistently indicated as being as high as 70kts during land crossing, models have in their latest run however scaled back the size of the rain event associated with the system should it cross the mainland, the precipitation forecasts still remain high @ 100mm+ accumulated for widespread areas of southern to central Japan but have been scaled back to around 20-50mm accumulated for central to northern areas. This is good news but still a great threat to any area that will be potentially affected. Some models also have lessened the forecast strength of the westerly’s, originally forecasting for 50kts around Okinawa now forecasting around 30kts(confirmed @ CIMSS), this again may change the result. Super Typhoon Songda is a very intense system now, while it will always inevitably loose strength during its northern travels it has the potential to be a very serious weather event for Japan, currently the hope is that JTWC have the right forecast numbers for their “correction” and the system tracks off shore from Japan. Short term however, the system will most definitely affect Ryukyu and Okinawa, with possible winds as high as 125kts and significant rain, and now seems most likely to affect the southern tip of the mainland of Japan.