NWS NATIONAL HURRICANE CENTER MIAMI FL AL312020
1500 UTC FRI NOV 13 2020
THERE ARE NO COASTAL WATCHES OR WARNING IN EFFECT.
INTERESTS IN NICARAGUA AND HONDURAS SHOULD MONITOR THE PROGRESS OF
THIS SYSTEM. A HURRICANE WATCH MAY BE REQUIRED FOR A PORTION OF
THAT AREA TONIGHT.
TROPICAL DEPRESSION CENTER LOCATED NEAR 14.2N 74.3W AT 13/1500Z
POSITION ACCURATE WITHIN 35 NM
PRESENT MOVEMENT TOWARD THE WEST-SOUTHWEST OR 250 DEGREES AT 6 KT
ESTIMATED MINIMUM CENTRAL PRESSURE 1007 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
REPEAT...CENTER LOCATED NEAR 14.2N 74.3W AT 13/1500Z
AT 13/1200Z CENTER WAS LOCATED NEAR 14.3N 74.0W
FORECAST VALID 14/0000Z 14.0N 75.0W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 50NE 50SE 0SW 50NW.
FORECAST VALID 14/1200Z 13.8N 76.0W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 60NE 60SE 20SW 60NW.
FORECAST VALID 15/0000Z 13.9N 77.3W
MAX WIND 60 KT...GUSTS 75 KT.
50 KT... 30NE 30SE 0SW 0NW.
34 KT... 80NE 60SE 30SW 70NW.
FORECAST VALID 15/1200Z 14.1N 79.0W
MAX WIND 70 KT...GUSTS 85 KT.
64 KT... 20NE 20SE 0SW 15NW.
50 KT... 40NE 40SE 0SW 30NW.
34 KT...100NE 80SE 40SW 100NW.
FORECAST VALID 16/0000Z 14.5N 80.9W
MAX WIND 85 KT...GUSTS 105 KT.
50 KT... 40NE 40SE 20SW 40NW.
34 KT...110NE 90SE 60SW 110NW.
FORECAST VALID 16/1200Z 14.9N 82.7W
MAX WIND 95 KT...GUSTS 115 KT.
50 KT... 40NE 40SE 20SW 40NW.
34 KT...110NE 90SE 60SW 110NW.
EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY
OUTLOOK VALID 17/1200Z 15.2N 85.7W...INLAND
MAX WIND 50 KT...GUSTS 60 KT.
OUTLOOK VALID 18/1200Z 14.7N 88.3W...POST-TROP/REMNT LOW
MAX WIND 25 KT...GUSTS 35 KT.
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.2N 74.3W
NEXT ADVISORY AT 13/2100Z
$$
FORECASTER BROWN
BULLETIN
Tropical Depression Thirty-One Advisory Number 1
NWS National Hurricane Center Miami FL AL312020
1100 AM EDT Fri Nov 13 2020
...NEW TROPICAL DEPRESSION FORMS IN THE CENTRAL CARIBBEAN SEA...
...EXPECTED TO STRENGTHEN AND APPROACH CENTRAL AMERICA AS A
HURRICANE EARLY NEXT WEEK...
SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.2N 74.3W
ABOUT 310 MI...500 KM SSE OF KINGSTON JAMAICA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WSW OR 250 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warning in effect.
Interests in Nicaragua and Honduras should monitor the progress of
this system. A Hurricane Watch may be required for a portion of
that area tonight.
DISCUSSION AND OUTLOOK
----------------------
At 1100 AM EDT (1500 UTC), the center of Tropical Depression
Thirty-One was located near latitude 14.2 North, longitude 74.3
West. The depression is moving toward the west-southwest near 7 mph
(11 km/h) and this motion is expected to continue through early
Saturday. A westward to west-northwestward motion at a slightly
faster forward speed is expected to begin by late Saturday and
continue through early Monday. On the forecast track, the system
will move across the central Caribbean Sea during the next day or
so, and approach the coasts of Nicaragua and northeastern Honduras
late Sunday and Monday.
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
The depression is forecast to strengthen into a tropical storm
later today or tonight. Additional strengthening is likely over
the weekend, and the system could be near major hurricane strength
when it approaches Central America.
The estimated minimum central pressure is 1007 mb (29.74 inches).
HAZARDS AFFECTING LAND
----------------------
Rainfall: Through Wednesday morning, Tropical Depression
Thirty-One is expected to produce 4 to 8 inches of rain, with local
12 inch totals, across portions of northern Columbia, Panama and
Costa Rica. Across Jamaica and southern Haiti, 2 to 4 inches are
expected, with local amounts up to 6 inches. Across remaining
sections of Central America, the system has the potential to produce
20 to 30 inches of rain with a focus across northern Nicaragua and
Honduras. This rainfall would lead to significant, life-threatening
flash flooding and river flooding, along with landslides in areas of
higher terrain.
NEXT ADVISORY
-------------
Next complete advisory at 500 PM EDT.
$$
Forecaster Brown
Tropical Depression Thirty-One Discussion Number 1
NWS National Hurricane Center Miami FL AL312020
1100 AM EDT Fri Nov 13 2020
Deep convection associated with the area of low pressure over the
central Caribbean Sea has increased and become more concentrated
since yesterday. One-minute GOES-16 visible satellite imagery shows
that the circulation has also become better defined, with a westerly
component seen in the low-cloud motion near the southwestern edge
of the primary convective mass. Subjective Dvorak intensity
estimates from both TAFB and SAB are T2.0, indicating that the
convection has become sufficiently organized for the system to be
classified as a tropical depression. The initial wind speed is set
at 30 kt, in line with the Dvorak classifications.
Environmental conditions of low vertical wind shear, warm sea
surface temperatures, and a moist atmosphere favor intensification
over the next few days. Given the current broad and sprawling
structure of the system, strengthening may begin as gradual today,
but once an inner core organizes, steady-to-rapid strengthening
appears likely. While the SHIPS rapid intensification index does not
show very high chances of rapid strengthening for any one 24-h
period over the next few days, it does indicate a 50/50 chance
(nearly 10 times the climatological mean) of a 65-kt increase in
wind speed over the next 72 hours. As a result, the NHC forecast
calls for significant strengthening during the 24 to 72 hour time
period, and the system could approach the coast of Central America
as a major hurricane in a few days. The NHC track forecast at days
4 and 5 shows the system weakening over land, however some of the
track guidance keeps the system just off the coast on Honduras at
that time. If a more northern track occurs, the system could be
stronger at 96 and 120 h if it remains over water.
The depression is moving west-southwestward at about 6 kt. A strong
mid-level ridge that lies over Florida and the western Atlantic
should steer the cyclone west-southwestward during the next 12 to 24
hours. After that time, the ridge is forecast to begin sliding
eastward, and a westward to west-northwestward motion should begin.
On the foreast track, the cyclone is expected to approach the
coast of Central America in 60-72 h. The track guidance is in good
agreement through the first couple of days, but there is increasing
cross-track spread after that time. The HMON, HWRF, and GFS show a
track near or north of the coast of Honduras after 72 hours, while
the ECMWF and UKMET are farther south. For now, the NHC track is
near the middle of the guidance envelope between the HFIP corrected
consensus model and the TCVA multi-model consensus.
Key Messages:
1. The depression is expected to strengthen to a hurricane while it
approaches the coast of Central America, and there is a risk of
dangerous wind, storm surge, and rainfall impacts across portions of
Nicaragua and Honduras beginning Sunday night. Hurricane Watches
will likely be issued for a portion of this area tonight.
2. Through Wednesday morning, heavy rainfall from Tropical
Depression Thirty-One may lead to life-threatening flash flooding
and river flooding across portions of Haiti, Jamaica and Central
America. Flooding and landslides from heavy rainfall could be
significant across Central America given recovery efforts underway
after Hurricane Eta.
FORECAST POSITIONS AND MAX WINDS
INIT 13/1500Z 14.2N 74.3W 30 KT 35 MPH
12H 14/0000Z 14.0N 75.0W 35 KT 40 MPH
24H 14/1200Z 13.8N 76.0W 45 KT 50 MPH
36H 15/0000Z 13.9N 77.3W 60 KT 70 MPH
48H 15/1200Z 14.1N 79.0W 70 KT 80 MPH
60H 16/0000Z 14.5N 80.9W 85 KT 100 MPH
72H 16/1200Z 14.9N 82.7W 95 KT 110 MPH
96H 17/1200Z 15.2N 85.7W 50 KT 60 MPH...INLAND
120H 18/1200Z 14.7N 88.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
$$
Forecaster Brown