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Hurricane Nora Discussion Number 15
NWS National Hurricane Center Miami FL EP142021
400 AM CDT Sun Aug 29 2021
There have been no recent in-situ observations for estimating the
intensity of Nora, but the cyclone is still fairly well-organized on
satellite images. Taking a blend of T- and Current Intensity
numbers from TAFB and SAB along with ADT estimates from UW-CIMSS
still supports keeping the system as a hurricane at this time.
Center fixes indicate that Nora is moving a little west of due
north at a decreased forward speed, or around 350/9 kt. The
tropical cyclone is expected to move north-northwestward to
northwestward during the next few days, on the southwestern side of
a mid-level ridge. This would take Nora over the eastern part of
the Gulf of California, but very near the coast of mainland Mexico
over the next few days. The track guidance has shifted somewhat to
the east, and now suggests that it is a very distinct possibility
that the system will move inland much sooner than shown by the
latest NHC track forecast.
The future intensity of Nora is of course highly dependent on how
soon the center moves inland. The official intensity forecast
assumes that the system will remain just offshore so that only slow
weakening will occur during the next 72 hours or so. This is in
good agreement with the NOAA corrected consensus guidance.
Alternatively, Nora may move inland sooner than indicated, in which
case the system would probably dissipate in 2 to 3 days or less.
Obviously, this intensity forecast is of low confidence.
Key Messages:
1. Nora is forecast to be at or near hurricane strength while
it moves near the coasts of Nayarit and Sinaloa through the
weekend and into Monday, and hurricane warnings or watches are in
effect for portions of that coastline. Interests in these areas
should closely monitor the progress of Nora and subsequent updates
to the forecast.
2. Heavy rain associated with Nora is expected across the west coast
of Mexico from the states of Colima northward to southern Sonora.
This rain will likely result in life-threatening flash flooding and
mudslides across these regions. Rainfall from Nora is likely to
spread into the southwestern U.S. and central Rockies during the
middle to latter portion of the week, bringing the potential for
flash flooding to the region.
3. Nora is forecast to move north-northwestward to northwestward
over the Gulf of California Tuesday and Wednesday, bringing a risk
of wind impacts to portions of the Mexican states of Baja California
Sur, northern Sinaloa, and Sonora. Given the above-average
uncertainty in the forecast intensity, confidence is not high enough
to determine the magnitude and location of these potential impacts.
FORECAST POSITIONS AND MAX WINDS
INIT 29/0900Z 22.5N 105.9W 65 KT 75 MPH
12H 29/1800Z 23.6N 106.8W 65 KT 75 MPH
24H 30/0600Z 24.2N 107.4W 60 KT 70 MPH
36H 30/1800Z 24.7N 108.1W 60 KT 70 MPH
48H 31/0600Z 25.2N 108.8W 60 KT 70 MPH
60H 31/1800Z 26.0N 109.5W 55 KT 65 MPH
72H 01/0600Z 27.0N 110.2W 55 KT 65 MPH
96H 02/0600Z 29.5N 111.0W 30 KT 35 MPH...INLAND
120H 03/0600Z...DISSIPATED
$$
Forecaster Pasch
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