TROPICAL STORM FELICIA DISCUSSION NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072015
900 AM MDT THU JUL 23 2015
Conventional satellite imagery and a couple of recent microwave
overpasses show that spiral banding has improved during the past
several hours, particularly over the eastern and southern portions
of the cyclone. Dvorak intensity estimates from both TAFB and SAB
are T2.5/35 kt, supporting an upgrade of the system to a tropical
storm. Although Felicia has about 24 hours or so before
moving over cooler water and into a more stable environment,
persistent northerly shear should impede any significant
strengthening. The statistical-dynamical intensity guidance all
show Felicia weakening to a remnant low in 48 hours, and this is
reflected in the official forecast. Global models subsequently
indicate the cyclone dissipating or opening up into a trough in 4
days or less.
The initial motion is estimated to be 320/11. Felicia is forecast
to continue moving northwestward within the mid-level flow on the
southwestern side of the subtropical ridge during the next 24-36
hours. Afterward, the dynamical models show Felicia gradually
turning westward as the system degenerates into a remnant low and is
steered by the low-level tradewind flow. The NHC forecast is
basically an update of the first advisory, and closely follows the
GFEX and TVCN multi-model consensus forecasts.
TROPICAL DEPRESSION SEVEN-E DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072015
300 AM MDT THU JUL 23 2015
Deep convection associated with the area of low pressure several
hundred miles southwest of the southern tip of the Baja California
peninsula has become better organized tonight, with a curved
band wrapping around the southern semicircle of the circulation.
Based on the increased convective organization, the system is now
classified as a tropical cyclone. The initial intensity is set to
30 kt based on the latest Dvorak estimate from SAB.
There is not much of an opportunity for the depression to
strengthen, with moderate northerly shear expected to persist until
the system crosses the 26C isotherm in about a day. As a result,
the intensity guidance shows little strengthening and the NHC
forecast follows this trend. However, it is possible that the
cyclone could briefly reach tropical storm status even though that
isn't explicitly forecast here. The cyclone should weaken to a
remnant low by 48 hours due to cold waters and a dry, stable
airmass. The low is forecast to dissipate by day 5.
The initial motion estimate is 330/08. The depression should
move northwestward around the southwestern periphery of the
subtropical ridge for the next 24 hours and then turn westward under
the influence of the low-level ridge as it becomes a shallow system.
The NHC track forecast is close to a blend of the GFS and ECMWF
models through dissipation.
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