[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT43 KNHC 071455
TCDAT3

Tropical Storm Julia Discussion Number   5
NWS National Hurricane Center Miami FL       AL132022
1100 AM EDT Fri Oct 07 2022

Earlier this morning, a concentrated burst of deep convection with
a high density of lightning developed near the center of the
cyclone while it was over the Guajira Peninsula, and microwave
imagery shows that convective banding has increased somewhat over
the adjacent waters.  An Air Force Reserve Hurricane Hunter aircraft
currently investigating the system so far has found maximum 925-mb
flight-level winds of 47 kt and SFMR surface winds of 34 kt, and on
that basis, the depression is upgraded to a 35-kt tropical storm.

Based on the latest aircraft fix, Julia is moving a bit faster
toward the west than expected with an initial motion of 280/16 kt.
A strong east-northeast to west-southwest oriented ridge which
stretches into the southern Gulf of Mexico should keep Julia on a
quick westward path during the next 48 hours.  Since the track
guidance has sped up a bit over the past few forecast cycles, the
official forecast now brings Julia to the coast of Nicaragua by
Sunday morning, which is a little sooner than was previously
forecast.  After landfall, the track guidance currently indicates
that Julia and its remnants should remain over Central America and
southern Mexico through Tuesday.

Stiff north-northwesterly shear (15-20 kt) is affecting Julia, and
that can be seen in the suppression of the northern edge of the
recent convective burst.  Shear diagnostics suggest that this shear
should abate soon, and Julia should commence a steady strengthening
trend during the next two days while it crosses the southwestern
Caribbean Sea.  Julia is forecast to become a hurricane by Saturday
evening, and the forecast peak intensity at the time of landfall in
Nicaragua is unchanged from the previous advisory.  The official
forecast at that time is a bit above HCCA and the IVCN consensus
aids, but it's still below SHIPS and LGEM guidance.  The NHC
forecast shows 72- and 96-hour remnant low points to indicate the
expected track over Central America, but it is highly likely that
the center will have dissipated by those times.


Key Messages:

1. Julia is forecast to strengthen into a hurricane by Saturday
evening while it moves over the southwestern Caribbean Sea, and a
Hurricane Warning is now in effect for San Andres, Providencia, and
Santa Catalina Islands.  A Hurricane Watch is also now in effect for
much of the Nicaragua coast.  Hurricane-force winds and a dangerous
storm surge are expected in areas where the core of the system
crosses the islands and moves onshore.

2. The risk of flash flooding continues today over portions of the
Guajira Peninsula. The potential for life-threatening flash flooding
and mudslides is expected to spread to portions of Central America
this weekend.


FORECAST POSITIONS AND MAX WINDS

INIT  07/1500Z 12.7N  73.1W   35 KT  40 MPH
 12H  08/0000Z 13.0N  75.5W   45 KT  50 MPH
 24H  08/1200Z 13.2N  78.7W   55 KT  65 MPH
 36H  09/0000Z 13.1N  81.3W   65 KT  75 MPH
 48H  09/1200Z 13.1N  83.6W   75 KT  85 MPH...INLAND
 60H  10/0000Z 13.6N  85.9W   45 KT  50 MPH...INLAND
 72H  10/1200Z 14.5N  88.5W   30 KT  35 MPH...POST-TROP/INLAND
 96H  11/1200Z 16.2N  93.5W   25 KT  30 MPH...POST-TROP/INLAND
120H  12/1200Z...DISSIPATED

$$
Forecaster Berg
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