Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
339 PM EDT Tue Jun 02 2026

Forecast Bulletin 02 June 2026 at 1940 UTC:

Mexico and North Central America...
On Tuesday, the region to the south of Mexico and north Central
America will be heavily affected by an upper level trough that
extends into the eastern Pacific over the southern Mexico region,
and a tropical wave that is currently propagating over the
southern Yucatan through El Salvador/Guatemala, and enters into
the East Pacific Ocean. To the east and west of this trough are
two mid to upper level ridges that are interacting with the
trough. This interaction with the divergent side of the trough is
located over northern Central America on Tuesday afternoon and
into the evening hours, favoring moderate to locally heavy
precipitation from west El Salvador, through Guatemala and into
southern Mexico. Similar amounts are expected in the southern
Belize region. On Wednesday, the wave continues to propagate
towards the southern Mexico region where it will decrease in
precipitation as it enters a generalized ridging region in the mid
to upper levels. During this day, a mid to upper level trough
extends into the Baja California region favoring some enhanced
divergence along the north central Altiplano region of Mexico. The
northern portion of Mexico can expect light to moderate amounts in
total accumulation. On Thursday, the tropical wave is slowing down
and remains over the southern portions of Mexico, where it is
expected to weaken. The southern region of Mexico can expect light
totals on Thursday. To the east, a new tropical wave is entering
north Central America, and expect enhanced moisture convergence
due to orographic lift in the region, favoring light precipitation
with the presence of a mid level ridge inhibiting deep convection.

Caribbean and the Bahamas...
The northern portion of the region is seeing the entry of a
frontal boundary, fueling instability and the potential for light
precipitation over the north Bahamas. The region can expect to see
a marginal risk of severe weather due to the base of a trough over
the United States eastern seaboard and entering the northern
Bahamas by the evening hours of Tuesday, and interacting with the
ridge over much of the Caribbean. Prefrontal troughing over Cuba
and Hispaniola will favor moderate and light convection,
respectively. Otherwise, the region is seeing enhanced Saharan Air
Layer from the east. On Wednesday, the frontal boundary weakens
over the central Bahamas while a new cold front behind it develops
to the north of the Bahamas by the evening hours. This will favor
moderate precipitation totals over the north and central portions
of the Bahamas. On Thursday, the secondary frontal boundary
remains over the north Bahamas, taking the place of the previous
frontal boundary that had entered the region. This will reinforce
the precipitation over the same region of the Bahamas. Over the
Greater Antilles, prefrontal troughing will favor trace to light
precipitation, as deep convection is inhibited by a mid to upper
level ridge over the West Caribbean.

South Central America and Northern South America...
Tropical waves are propagating over the region and enhancing the
convection that will favor heavy precipitation on Tuesday. A
tropical wave is expected over western Panama, where it will
interact with the cyclonic circulation associated with the monsoon
through and being the process on moist onshore flow entering the
Pacific coasts of Costa Rica, Panama and west Colombia. Enhanced
moist onshore flow is expected in west Colombia where expect heavy
precipitation that will locally exceed the forecast amount. Costa
Rica and Panama can expect similar higher local precipitation
totals. Another tropical wave is expected to enter east Colombia
and west Venezuela, which will begin to interact with the Andes
region of Colombia and favor heavy precipitation, To the east, a
tropical wave is expected in Guyana by the evening of Tuesday, but
this wave is surrounded by an environment with less available
moisture, favoring light to moderate precipitation over the
Guianas and the eastern Amazon Basin. On Wednesday, similar
conditions continue in southern Central America and northwest
South America, with the continued presence of propagating tropical
waves. The moist onshore flow continues over much of Costa Rica,
Panama, and west Colombia, favoring the heavy precipitation on
Wednesday. Similarly, the central portions of Colombia and
Venezuela will see the effects of the tropical waves enhancing
deep convection over much of the region. By Thursday, model
guidance begins to diverge in the speed of propagation for the
tropical waves over southern Central America and how soon they
will begin to be absorbed into the monsoon trough cyclonic
circulation. The tropical wave affecting Costa Rica enters
Nicaragua by Thursday, while enhancing the cyclonic circulation
and moist onshore into portions of southwest Nicaragua and Costa
Rica. Another tropical wave is expected to reach Panama by the
evening hours of Thursday, where it will have enhanced cyclonic
circulation associated with the monsoon trough. The speed of this
second wave differs between models, but there is confidence that
this will wave will favor moist onshore flow into west Colombia on
Thursday, and thus expect heavy precipitation to continue on
Thursday into Friday. Similarly, a tropical wave entering east
Colombia and west Venezuela will see ventilation aloft with
increased divergence from interacting upper level systems over
north South America. Expect heavy recitation from Colombia into
west Venezuela. A new tropical wave is entering the Guianas by the
evening on Thursday, favoring moderate precipitation totals in the
coastal regions of French Guiana and Amapa-Brasil.

Positions of Tropical/Easterly Waves Initialized at 12 UTC
TYP SOF INIT 03/00 03/12 04/00 04/12 05/00 05/12 06/00 06/12
TW  12N  21W  24W   29W   33W  37W   42W   46W   50W  54W
TW  12N  42W  44W   46W   48W  50W   52W   55W   58W  60W
TW  10N  55W  58W   60W   63W  66W   69W   72W   74W  76W
TW  12N  67W  70W   72W   75W  78W   81W   83W   85W  88W
TW  17N  80W  81W   82W   83W  85W   86W   88W   89W  90W
TW  21N  90W  92W   94W   96W  98W  100W  102W  DISS  ---
TW  17N 108W  110W  113W 116W EXITS  ---   ---   --- 

Castellanos...(WPC)