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FXCA20 KWBC 131842
PMDCA

Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
141 PM EST Thu Nov 13 2025

Forecast Bulletin 13 November 2025 at 1840 UTC:

Mexico and Central America:

Heavy precipitation due to a shear line and frontal system is
expected to continue today through Saturday morning in Belize and
Quintana Roo in Mexico. Strong low-level flow and ample
precipitable water will continue to move onshore from the east
into the evening hours on Friday, before dissipating overnight on
Friday and into Saturday. Precipitation totals up to 40-80mm are
still expected for this area on Friday, and 25-50mm is expected on
Saturday. Remnant and reduced moisture will continue to make its
way into the region on Saturday evening and Sunday bringing
lighter precipitation. On Sunday night, moisture availability will
further diminish and any remaining precipitation will be localized
and light, most likely in the form of showers.

In Baja California, a potent mid-latitude system, in the form of a
cutoff low in the upper levels, will impact the northern portions
of Baja California beginning Saturday, bringing precipitation from
then until Monday. A cold front associated with the system will
enter the coast from the Pacific, and with added low-level
moisture convergence and strong upper-level divergence, heavy
precipitation is expected, particularly on Saturday. A
precipitation maximum of 20-45mm is expected on Saturday into
Sunday.

In Costa Rica and Panama, the presence of the monsoon trough and
the Panamanian Low will promote a broad cyclonic circulation in
the low levels, and onshore flow of moisture will continue to move
from the Atlantic into the northern coasts of Costa Rica and
Panama today through Saturday. By Sunday however, drier air is
anticipated to intrude into the region, and precipitation will
become much lighter and more localized. Localized heavy
precipitation is still possible at higher elevations at this point
due to orographic enhancement. On the Pacific side, a long fetch
plume of moisture will remain in place through the forecast
period. Much of the moisture in the low-levels will flow mostly
parallel to the southern coasts, thus, precipitation will be in
the form of heavy but localized convection.

The Bahamas and Caribbean:

A frontal system, which is currently bringing heavy precipitation
to Belize and Quintana Roo in Mexico, will continue its slow
southeastward progression through the Atlantic today and Friday.
The cold front currently extends from the southern Bahamas,
central Cuba, and the Caribbean Sea, just south of Cuba. Beginning
on Friday, this front is expected to begin to dissipate, as a new
cold front moves in and takes its place. Precipitation will occur
along with the progression of the front in the central and
southern Bahamas and the east coast of Cuba on Friday and
Saturday, before moving into the island of Hispaniola on Sunday.
Precipitation is expected to be light in most regions, with
moderate amounts possible in isolated areas.

Tropical South America:
In northwest Brazil, a plume of moisture from the Amazon is
expected to move westward towards southeast Colombia and northeast
Peru on Saturday in the early morning hours. With the addition of
low wind shear, but sufficient upper-level divergence, along with
local and diurnal effects, heavy precipitation in the form of
strong thunderstorms is expected on Saturday morning. In the west
coast of Colombia, a long fetch plume of moisture associated with
the presence of the monsoon trough will aid in the onshore flow of
moisture from the west. Heavy precipitation for west Colombia is
expected to occur today and Friday, with lingering but lighter
precipitation on Saturday into Sunday. The highest precipitation
totals are forecast to occur on the coast, where orographic ascent
will be enhanced. In the interior portions of tropical South
America, precipitation will be caused mostly by local, diurnal,
and orographic effects, with daily convection expected in much of
the north-central regions throughout the forecast period. Late
over the weekend, a plume of drier air will move in from the east
and intrude into north-central Brazil and the Guianas, and calmer
conditions should be expected.


Positions of Tropical/Easterly Waves Initialized at 12 UTC
TYP SOF  INIT  14/00  14/12  15/00  15/12  16/00  16/12  17/00
--  --    --    ---   ---


For the latest available charts please visit:
https://www.wpc.ncep.noaa.gov/international/crb_day1-3.shtml

Blanco-Alcala...(WPC)
$$