Aric Dunn wrote:Derek Ortt wrote:Aric... you do not use a 90 percent reduction automatically from all levels.
I highly recommend most here read the Franklin et al. 2003 paper that addresses this topic
umm yeah .. i was going off of there last VDM .. and they were flying near the same level .. and i figured out what they were using then and so i used 90% this time as well .. and they did increase the winds to 70mph on the 2pm advisory
Yes, but that was based of SFMR, which is providing higher-than-normal FL to surface conversions, in some places with the reduction factor nearing 200%.
Typical 1000ft->surface reduction is around .8, with some variation as storms that are flown into at this level prove to be quite volatile.
Here, I don't think an accurate reduction factor can be established for large areas of the storm . . . you might need to calculate one or two for each set of HDOBs that comes in, actually. That's actually some of the most interesting data this short flight collected . . . the observations that support atypical wind profiles . . . which may be a temporary thing or may be a life-long characteristic of this storm.
You can tell by the satellite presentation it's going to be a bad one. Dean struggled for the first day or two after it was upgraded(remember during the mid-afternoon for several days it looked dead?), this one has not AT ALL. 
and there's nothing there! Now we have a 70 mph TS! A good bit of development definitely! I don't know if it's a hurricane yet, it could be, but if it's not it's VERY close.