Thursday, October 1, 2015

"How will I know?"
- 1985 single by Whitney Houston (Music Video on VEVO)

  • The 11:00 AM NHC Advisory as shown below indicates Joaquin is moving north, and located at 23.8 North, 74.8 West as reported by Air Force reconnaissance in the storm. The storm has not crossed the 75 degrees west longitude "line of consequence" established by our investigation posted below from Thu 10/1.
  • If the eastward pressing frontal boundary just off the Eastern seaboard continues edging toward the hurricane, it will be evidenced by an increase in Joaquin's forward speed over the next 24-48 hours. 
  • These and other factors, including the brief retrograde (or reverse motion) of a strong high pressure system in southern Canada, provides increased confidence the hurricane should be able to pursue an "escape route" through the west Atlantic.
  • However, with 1,000+ miles of ocean the hurricane has yet to traverse, it is not time to sound the "all clear." We would need to see a consistent movement to the northeast over a 24-hour period before considering a reduced posture.


As the waiting game begins for the hurricane to makes the northwesterly then northerly turn, our tropical team has selected a critical observation point everyone can follow along with us. Or in the timeless words of Ms. Whitney, "I'm asking you what you know about these things."

CROSSING THE LINE This group observation is based on these questions: Will Joaquin turn before crossing the line? Would the future track be affected if this turn occurs later than planned? The line we are talking about is 75 degrees west longitude, the next major longitudinal grid border shown above just left of the eye.

HOW THIS WORKS Most of the computer model guidance, as well as official NHC forecasts, have the storm starting the "turn" before 75 degrees west longitude. 
  • On Thursday, the storm followed a W to SW path. Our thought process is simply that if Joaquin crosses 75 west and by Friday mid-day still has not begun to turn, would this affect the eventual projected path, which has shifted farther east.
  • On the other hand, crossing or not crossing the 75 west line may have no bearing on the storm's path due to other influences such as the trough across Florida or the high in Canada -- all of which are factors affecting where Joaquin will go.
HOW WILL WE KNOW? According to the NHC Forecast Advisory, the hurricane path is set to cross these points in the next 24-48 hours. Let's all see what happens:
  1. At 8 PM tonight, the forecasted position is 22.9 North, 74.2 West. As of 4:40 PM, Joaquin was at approximately 23.1 North and 74.4 West. This is our data starting point, although we will include track verification as a reference. 
  2. At 8 AM Friday, the forecasted position is 23.7 North, 74.6 West. This is one of the critical time points, at which time Joaquin should be showing a discernable turn to the northwest.
  3. By 8 PM Friday, the forecasted position is 25.2 North, 74.4 West. This point is where the storm should be generally moving due north or slightly NNW. 
WHAT'S THE POINT OF IT? We have chosen 75 west as our line of demarcation. We hypothesize the storm needs to complete the turn before this line, and if not, it may affect the track and everyone's expectation that the bullet has been dodged. With your help, it will be interesting to see how this plays out in the next 24 hours.


Unknown said...

How many of your group are pulling the"all-nighter"tonight,1 OCT,and how much sleep can you get during the Joaquin event?How much further south can Joaquin travel before the models are totally inaccurate?Thank you for the detailed information and the difficult work involved.

Westsidehideaway said...

I'll start pulling the all night weather watch after I watch the Ravens Trounce. It be a nice break from weather worry.

Mr. Foot said...

A few college forecasters have stayed up to 1 AM for seeing the overnight model output, but that is par for the course- when in college!

Amy said...

Anne Arundel county OEM has posted that we dodged a major bullet. Feels a bit premature.

Amy said...

Anne Arundel county OEM has posted that we dodged a major bullet. Feels a bit premature.

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