[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT44 KNHC 071459
TCDAT4

HURRICANE MATTHEW DISCUSSION NUMBER  38
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142016
1100 AM EDT FRI OCT 07 2016

The satellite presentation has degraded during the past several
hours, and the eye is not very distinct. However, the SFMR and
flight-level wind data from an Air Force reconnaissance plane
indicate that the initial intensity is still 105 kt.

Matthew is expected to change little in intensity during the next 6
to 12 hours, but it should begin to weaken at a faster pace in
24 hours while the shear increases, and by the end of the forecast
period, Matthew is expected to become a tropical depression.

Fixes from a reconnaissance plane indicate that Matthew is moving
toward the north-northwest or 345 degrees at 10 kt. Matthew is
reaching the northwestern edge of the subtropical ridge and
encounter the mid-latitude westerlies. This flow pattern should
steer the hurricane northward and then northeastward during the
next 36 hours. After that time, the flow pattern is forecast
to change again and a weakening Matthew should then turn southward
and southwestward. The NHC forecast is a little bit to the
north from the previous one during the first 24 to 36 hour period
following the multi-model consensus. After 72 hours, models
continue to vary the flow pattern and the confidence in the track
forecast is low.


KEY MESSAGES:

1.  We have been very fortunate that Matthew's category 3 winds have
remained a short distance offshore of the Florida Coast thus far,
but this should not be a reason to let down our guard.  Only a
small deviation to the left of the forecast track could bring these
winds onshore.  The western eyewall of Matthew, which contains
hurricane-force winds, is expected to move over or very near the
coast of northeastern Florida and Georgia today.

2.  Hurricane winds increase very rapidly with height, and occupants
of high-rise buildings in the Jacksonville area are at particular
risk of strong winds. Winds at the top of a 30-story building will
average one Saffir-Simpson category higher than the winds near the
surface.

3.  The water hazards remain, even if the core of Matthew remains
offshore.  These include the danger of life-threatening inundation
from storm surge, as well as inland flooding from heavy rains from
Florida to North Carolina.

4.  The National Hurricane Center is issuing Potential Storm Surge
Flooding Maps, and Prototype Storm Surge Watch/Warning Graphics for
Matthew.  It is important to remember that the Potential Storm Surge
Flooding Map does not represent a forecast of expected inundation,
but rather depicts a reasonable worst-case scenario -- the amount of
inundation that has a 10 percent chance of being exceeded.

FORECAST POSITIONS AND MAX WINDS

INIT  07/1500Z 29.4N  80.4W  105 KT 120 MPH
 12H  08/0000Z 30.8N  80.7W  100 KT 115 MPH
 24H  08/1200Z 32.5N  79.9W   85 KT 100 MPH
 36H  09/0000Z 33.5N  78.1W   75 KT  85 MPH
 48H  09/1200Z 33.5N  76.0W   60 KT  70 MPH
 72H  10/1200Z 32.0N  74.0W   50 KT  60 MPH
 96H  11/1200Z 28.0N  75.0W   35 KT  40 MPH
120H  12/1200Z 27.0N  76.0W   30 KT  35 MPH

$$
Forecaster Avila
This weather bulletin was brought to you by:
www.nashvilleweather.net