000
WTPZ41 KNHC 020840
TCDEP1

Tropical Storm Juliette Discussion Number   5
NWS National Hurricane Center Miami FL       EP112019
300 AM MDT Mon Sep 02 2019

After struggling to strengthen during the previous 12-h period due
to the entrainment of mid-level dry air, a strong burst of deep
convection, accompanied by frequent lightning and cloud tops near
-90C, has developed near the well-defined low-level circulation
center. A nearly circular CDO feature has also formed over the
center, and the upper-level outflow has improved and expanded in all
quadrants. During the past few hours, SSMI/S and AMSU microwave
satellite data indicate that a primitive mid-level eye feature had
formed, and recent satellite intensity estimates from TAFB and
UW-CIMSS SATCON were T3.5/55 kt and 57 kt, respectively. Based on
these data, the initial intensity has been increased to 55 kt.

The initial motion is estimate is 300/12 kt. There is no significant
change to the previous forecast track or rationale. A deep-layer
ridge anchored to the north of Juliette is expected to change
little, driving Juliette on a general west-northwestward track
throughout the 5-day period. As a result, the new NHC track forecast
is very similar to the previous advisory track, and lies down the
middle of the tightly clustered model guidance.

Now that a nearly complete mid-level eye feature has formed, rapid
intensification is expected to occur during the next 24 hours due to
Juliette being embedded within very favorable environmental
conditions consisting of low vertical wind shear near 5 kt, an
unhindered outflow pattern, and a moist mid-level environment, along
with traversing warm sea-surface temperatures (SST) of 28-29 deg C.
Thereafter, a slower rate of strengthening is expected through 36-48
hours due to the cyclone moving over marginal SSTs. Steady weakening
is forecast on days 3-5 when Juliette will be moving over sub-26C
SSTs despite low shear conditions. The new official intensity
forecast is a little above all of the available intensity guidance,
and shows the same peak intensity as the previous advisory, except
that the time of occurrence has been moved forward by 24 hours.

FORECAST POSITIONS AND MAX WINDS

INIT  02/0900Z 16.2N 111.8W   55 KT  65 MPH
 12H  02/1800Z 17.0N 113.2W   70 KT  80 MPH
 24H  03/0600Z 17.9N 114.9W   85 KT 100 MPH
 36H  03/1800Z 18.5N 116.4W   90 KT 105 MPH
 48H  04/0600Z 19.0N 117.7W   90 KT 105 MPH
 72H  05/0600Z 20.0N 121.3W   75 KT  85 MPH
 96H  06/0600Z 21.5N 125.2W   60 KT  70 MPH
120H  07/0600Z 23.0N 129.5W   45 KT  50 MPH

$$
Forecaster Stewart