Tropical Discussion - International Desks
NWS Weather Prediction Center College Park MD
318 PM EDT Tue Jun 16 2026

Forecast Bulletin 16 June 2026 at 1930 UTC:

Mexico and Northern Central America...
An upper level trough will continue deepening over north and
northwestern Mexico in the next 24 hours with a more structured
reflection in mid levels while the upper level high pressure
system currently centered over the central and north Mexican
region continues weakening. These upper level conditions will
support deep convection by lifting the abundant low level moisture
present across northeastern Mexico associated with a trough of low
pressure and the inflow of strong moisture advection from
southeast winds along the Caribbean sea and the Gulf. The rain
associated with this system will be more abundant offshore, but
moderate accumulation totals along northeastern Mexico will
continue today.
On Wednesday, a drying trend will establish over northeastern
Mexico as the upper trough tracks northeastward. Along the western
Mexican coast and central region, enhanced values of precipitable
water (PWAT) associated with low level convergence interacting
with local orography will favor moderate accumulation total in the
next three days. Farther south, western tracking tropical waves
embedded in the monsoon trough will interact with the mountainous
terrain of south Mexico and Central America, enhancing orographic
lift and favoring moderate rainfall accumulation totals. 

Caribbean and the Bahamas...
The Atlantic subtropical ridge will remain dominant, inducing
large-scale subsidence that will suppress deep convection across
most of the basin. The exception will be over Cuba, where a
mid-to-upper level trough will provide sufficient dynamic lifting
to support scattered moderate convective showers, with daily total
rain accumulation maxima of 20mm today, before conditions become
slightly drier afterward.

Northern South America and South Central America...
Two upper level ridges, currently centered over the Caribbean sea
basin and the second over northeastern Brazil, will maintain
subsidence over their respective areas while continuing moving
westward in the next 72 hours. A negative PWAT anomaly will be
associated with these conditions through the upcoming days.
However, this setup will confine a moist equatorial corridor
across Venezuela and Colombia, where a series of westward moving
tropical waves will trigger widespread convection today with
elevated total precipitation maxima, especially across north and
northwest Colombia.
By Wednesday and Thursday, as the tropical wave currently located
over the Colombian Pacific coast propagates into the East Pacific,
the enhanced moist onshore flow will undergo orographic lifting
along the Pacific slopes of Costa Rica and western Nicaragua,
migrating the rainfall maxima westward.



Tropical Waves:
SOF  Init  17/00  17/12  18/00  18/12  19/00  19/12 20/00 20/12
10N  49W    51W    53W    56W    59W    62W    65W   68W   72W  
13N  67W    70W    74W    78W    82W    84W    87W   89W   90W  
15N  80W    82W    85W    88W    90W    92W    93W   94W   96W  
14N  89W    92W    95W   DISS    ---    ---    ---   ---   ---  
12N  98W   100W   103W   105W    DISS   ---    ---   ---   ---    

Sanchez-Perez...(WPC)