The purpose of this blog is to give the public in the Mid Atlantic region the background behind the forecasts.
By: weatherenthusiast1 , 6:44 AM GMT on October 26, 2012
You have likely heard about Hurricane Sandy- but do you know the facts?
Fact #1: It will impact a large area of the Northeast
Fact #2: High winds, rain, and flooding are likely over a large area
Myth #1: We know where the storm is headed
I want to emphasize why we don't have a good handle on the exact track and why we should not focus on the exact track at this time.
1. This is like predicting any other hurricane track, but in some respects harder. The pieces of the puzzle important to Sandy's track have not fully arrived to the Contiguous US and thus have not been properly sampled. Let's look at how uncertain things can be.
Take a look at this link: Model Errors
At this time, the storm is at least 84 hours away. The error in track has averaged about 36 mi - 229 mi. That is why we have a cone of uncertainty: landfall can occur anywhere between Maryland and Massachusetts.
Also, take a look at this link: ECMWF 500mb Reanalysis
Clearly, at 96 and even 72 hours out, there were important upper level differences between what was modeled and what actually happened.
Finally, this storm will likely transition to an extratropical cyclone. It is well documented that this transition (and the reintensification) that could occur is very difficult to model. This is why we need to wait for short range models like the NAM to become more in range. These HiRes models will allow a better pinpoint on the track within 48 hours.
At this range, the best thing to do is take each individual model run with a grain of salt. Using the ensembles, and ensemble means will give a better picture of any changes in the track.
GFS and its ensembles seem to have moved further north in its 0Z run. This is matched by CMC and its recent ensemble tracks.
ECWMF continues to be very consistent in its NJ/DE landfall.
NAM has a similar NJ/DE landfall but is less accurate in this range.
NOGAPS continues to be consistent with a NJ landfall.
Thanks for reading! Check back for an update tomorrow at this time!
0Z 10/27: Model Update: Focus on Dynamic Models: (NAM/GFS/ECWMF/CMC/NOGAPS)
0Z 10/28: Short Range Model Update (NAM/WRF)
10/28-10/31: Live Blog Updates
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.