998
FXCA20 KWBC 202013
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
312 PM EST TUE JAN 20 2026
FORECAST BULLETIN 20 JANUARY 2026 AT 2010 UTC:
THE TROPICAL REGION IS EXPECTED TO REMAIN GENERALLY QUIET, WHICH
IS NORMAL FOR THE TIME OF YEAR. THAT SAID, THE CARIBBEAN COAST OF
CENTRAL AMERICA IS FORECAST TO OBSERVE SIGNIFICANT RAINFALL OVER
THE NEXT THREE DAYS. GENERALLY DUE TO ONSHORE FLOW AND MOISTURE
CONVERGENCE, EITHER DUE TO A LOW-LEVEL TROUGH NEAR HONDURAS AND
BELIZE, OR NEAR THE MONSOON TROUGH IN AND AROUND COSTA RICA.
GENERALLY SPEAKING, TOTAL 3-DAY RAINFALL ACCUMULATIONS ACROSS THE
CARIBBEAN COAST OF CENTRAL AMERICA COULD BE AROUND 1 TO 4 INCHES,
WITH POSSIBLY ISOLATED HIGHER AMOUNTS OVER NORTHERN HONDURAS.
ISOLATED PORTIONS OF THE CARIBBEAN ISLANDS COULD OBSERVE 1 TO 2
INCHES OF RAIN OVER THE NEXT THREE DAYS, WITH THE LATEST MODEL
GUIDANCE SUGGESTING THESE TOTALS IN AREAS OF THE NORTHERN COAST OF
THE DOMINICAN REPUBLIC, EASTERN COASTAL PUERTO RICO, AND ACROSS
THE ISLAND CHAIN OF THE LESSER ANTILLES, FROM GUADELOUPE TO SAINT
LUCIA. ACROSS TROPICAL SOUTH AMERICA, WESTERN COLOMBIA AND ECUADOR
ARE ALSO FORECAST TO OBSERVE UP TO 3 INCHES ACROSS ISOLATED AREAS
DUE TO DEEP MOISTURE FROM THE PACIFIC AND ONSHORE FLOW.
A BROAD SURFACE HIGH PRESSURE ACROSS THE CENTRAL ATLANTIC WILL
DOMINATE THE WIND FLOW ACROSS THE ATLANTIC BASIN OVER THE NEXT FEW
DAYS. HOWEVER, THERE IS A COLD FRONT ACROSS THE WESTERN TROPICAL
ATLANTIC WITH AN ASSOCIATED SHEAR LINE TO ITS WEST SOUTHWEST,
WHICH CROSSES THE BAHAMAS AND CUBA, INTO THE CARIBBEAN TODAY AND
TONIGHT. ANOTHER THING OF NOTE IS A LOW-LEVEL TROUGH PRESENT OVER
THE GULF OF HONDURAS, THIS TROUGH JUST NORTH OF HONDURAS IS
CONTRIBUTING TO THE LOW-LEVEL MOISTURE CONVERGENCE THAT WILL CAUSE
SIGNIFICANT RAINFALL OVER NORTHERN HONDURAS, WITH UP TO 100 MM OF
RAIN ACROSS ISOLATED AREAS POSSIBLE. THE AFOREMENTIONED SURFACE
HIGH PRESSURE WILL ALSO ALLOW FOR RELATIVELY STRONG LOW-LEVEL
WINDS ACROSS THE TROPICAL ATLANTIC (MAINLY SOUTH OF 22N) AND
ACROSS THE CARIBBEAN, WITH LOW-LEVEL EASTERLY WINDS GENERALLY IN
THE VICINITY OF 20 TO 30 KNOTS OVER THE NEXT THREE DAYS.
IN THE MID LEVELS, THE REGION WILL BE MOSTLY UNDER A HIGH
PRESSURE, CAUSING SUBSIDENCE ACROSS MOST OF THE AREA, WHICH IS
PART OF THE REASON WHY THE HIGH AMOUNTS OF RAIN IN THE FORECAST IS
LIMITED TO A RELATIVELY SMALL COVERAGE AREA. THAT SAID, A
MID-LEVEL LOW PRESSURE IS FORECAST TO MOVE TO THE EAST OF THE
LEEWARD ISLANDS BY THURSDAY, CAUSING A MID-LEVEL JET OVER THE EAST
AND NORTHEASTERN CARIBBEAN ISLANDS, WHICH WILL PROMOTE SOME
VENTILATION FOR THUNDERSTORM DEVELOPMENT.
ACROSS THE UPPER LEVELS, THE SYNOPTIC PATTERN IS SIMILAR TO THAT
OF THE MID-LEVELS. A RIDGE OF HIGH PRESSURE WILL DOMINATE THE
TROPICAL REGION, PROMOTING SUBSIDENCE ACROSS MOST OF CENTRAL
AMERICA AND THE CARIBBEAN. THAT SAID, AN UPPER TROUGH IS FORECAST
ACROSS EASTERN MEXICO BY THURSDAY, WHICH COULD CAUSE SOME
DIVERGENCE TO ITS EAST AND INTO THE GULF. AN UPPER-LEVEL LOW IS
ALSO FORECAST ACROSS THE TROPICAL ATLANTIC FROM WEDNESDAY INTO
THURSDAY, WHICH WILL CAUSE LOCALLY STRONGER WINDS IN THE UPPER
LEVELS ACROSS THE CARIBBEAN ISLANDS ON WEDNESDAY INTO THURSDAY,
WITH SOME DIVERGENCE POSSIBLE ACROSS THE LEEWARD ISLANDS. THIS
WOULD FURTHER PROMOTE VENTILATION ALOFT FOR THUNDERSTORMS ACROSS
THE LESSER ANTILLES ON THURSDAY.
ALAMO...(WPC)
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