Tropical Storm Chris Discussion Number 9
Wiki-Hurricanes Forecast Center
5:00 AM EDT Tue Jul 10 2018
Chris' cloud pattern has become better organized since the previous advisory, with the formation of a prominent spiral band in the southern quadrant, as well as deeper convection to the northwest of the center where it has until recently been lacking in vigor. The combination of dry air and cold water upwelling continues to hinder the formation of a solid eyewall, though it would not take much for this process to complete. A reconnaissance aircraft is currently investigating the cyclone, reporting a minimum barometric pressure of 993mb. Flight-level winds of 67kt support surface winds of around 55kt; however, the initial intensity has been held at 60kt under the assumption stronger winds exist in either the northeast or southwest quadrants. In stationary systems, there is no preferred quadrant of maximum winds.
The storm has been meandering for days, but things are about to change. An upper-level trough is forming over Canada, and this feature should push southward later today, providing sufficient steering flow to direct Chris to the northeast. This track should keep it well offshore the East Coast of the United States, but bring it very close to Newfoundland in about three days as an extratropical cyclone.
Water temperatures at Buoy 41002 southwest of the center have continued to fall to near 25C, indicating that cold water upwelling continues. However, Chris has a fairly compact radius of maximum winds, and it is beginning to meander away from the location it has been for the past several days. This should allow for steady intensification as the system remains in a low wind shear environment. In fact, as the upper-level trough moves southward, outflow channels should only become more distinct. Dry air continues to lurk near the cyclone, but the combination of light upper-level winds and warm ocean waters should keep this issue at bay. The intensity forecast is largely a reflection of the previous one, calling for Chris to become a hurricane in a few hours and peak with winds of 80kt before undergoing extratropical transition.
FORECAST POSITIONS AND MAX WINDS
INIT 10/0900Z 60 KT 70 MPH
12H 10/1800Z 70 KT 80 MPH
24H 11/0600Z 80 KT 90 MPH
36H 11/1800Z 80 KT 90 MPH
48H 12/0600Z 75 KT 85 MPH
72H 13/0600Z 60 KT 70 MPH...POST-TROP/EXTRATROP
96H 14/0600Z 40 KT 45 MPH...POST-TROP/EXTRATROP
120H 15/0600Z...DISSIPATED