036
FXCA20 KWBC 281925
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
325 PM EDT THU MAY 28 2026
FORECAST BULLETIN 28 MAY 2026 AT 1930 UTC:
IN MEXICO AND NORTH CENTRAL AMERICA...
AN UPPER LEVEL TROUGH IS CURRENTLY DIGGING INTO THE SOUTHERN GULF
AND WILL BEGIN TO INTERACT WITH A DEVELOPING RIDGING PATTERN IN
THE CARIBBEAN SEA AND LEADING TO THE INCREASE IN UPPER LEVEL WIND
SPEEDS ACROSS THE YUCATAN PENINSULA. THIS PATTERN WILL CONTINUE
FOR THURSDAY AND FRIDAY. BY SATURDAY, EXPECT THE DECAY OF THE
STRUCTURE OF THE UPPER TROUGH. REGARDLESS, SPEED DIVERGENCE WILL
REMAIN OVER THE YUCATAN PENINSULA. THE DYNAMIC UPPER LEVEL WIND
PATTERN OVER THE YUCATAN WILL SUPPORT THE DEVELOPMENT OF SHORTWAVE
TROUGHS IN THE MID-LEVELS FOR THE NEXT THREE DAYS.
THE PRESENCE OF THE DEVELOPING MID-TO-UPPER LEVEL RIDGE IN THE
WEST CARIBBEAN SEA WILL LEAD TO THE MEAN STEERING WIND-FLOW TO BE
FROM THE SOUTHEAST. CONSEQUENTLY, EXPECT LOW LEVEL TROUGHS TO MOVE
ALONG THE CARIBBEAN COASTS OF NICARAGUA, HONDURAS, AND EVENTUALLY
YUCATAN WITH THIS FLOW PATTERN. CURRENTLY, THERE IS A WEAKENING
TROPICAL WAVE THAT WILL BE ENTERING THE YUCATAN PENINSULA AND WILL
INCREASE MOISTURE CONVERGENCE AND LOW LEVEL CYCLONIC ROTATION. AT
THE SAME TIME EXPECT THE BRIEF DEVELOPMENT OF A LOW LEVEL TROUGH
ACROSS THE WEST YUCATAN PENINSULA AS THE INTERACTION BETWEEN THE
UPPER RIDGE AND TROUGH INCREASES. THIS DYNAMIC LOW LEVEL PATTERN
WILL SUPPORT MODERATE TO ENHANCED ACCUMULATIONS ACROSS THE
YUCATAN, GUATEMALA, AND BELIZE.
BY FRIDAY, THE MID-TO-UPPER LEVEL TROUGH WILL CONTINUE TO SUPPORT
DIVERGENCE INTO THE REGION. THOUGH, THE LOW LEVEL WIND DIRECTION
WILL BE MORE SOUTH-SOUTHEASTERLY AT THAT POINT. MODERATE TOTAL
PRECIPITATION MAXIMA IS LIKELY IN QUINTANA ROO, BELIZE, AND
GUATEMALA FOR FRIDAY AS THERE WILL STILL BE HIGH PRECIPITABLE
WATER VALUES. BY SATURDAY, MODERATE PRECIPITATION ACCUMULATIONS
WILL BECOME CONFINED TO THE CARIBBEAN COAST OF THE YUCATAN
PENINSULA AND THE HIGHER TERRAIN IN GUATEMALA. THE MAIN DRIVERS
FOR THE INITIATION OF PRECIPITATION WILL BE LOCAL AND OROGRAPHIC
EFFECTS. MEANWHILE, THE MOISTURE CONTENT WILL REMAIN HIGH.
ELSEWHERE IN MEXICO, A LOW-TO-UPPER LEVEL TROUGH WILL BE PRESENT
ACROSS THE SOUTHERN GULF ON SATURDAY AND IT WILL SUPPORT THE
INCREASE IN EASTERLY LOW LEVEL WINDS INTO NORTH-CENTRAL MEXICO.
THIS WIND FLOW WILL ASSIST IN TRANSPORTING MOIST AIR INTO THE
REGION. ALSO STARTING ON SATURDAY AFTERNOON, THERE WILL BE A BRIEF
PERIOD WHERE THE UPPER LEVEL WIND PATTERN WILL BECOME DIFFLUENT
AND IT WILL SUSTAIN UPPER DIVERGENCE. THESE CONDITIONS WILL FAVOR
THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS, YIELDING MODERATE
TOTAL PRECIPITATION MAXIMA.
ALONG THE PACIFIC COASTS OF SOUTHWEST MEXICO, GUATEMALA, AND EL
SALVADOR, EXPECT THE DEVELOPMENT OF DAILY SHOWERS AND
THUNDERSTORMS ACROSS THE REGION. THE REGION WILL REMAIN MOIST FOR
THE NEXT THREE DAYS. A GENERALIZED TROUGHING LOW LEVEL WIND
PATTERN WILL DEVELOP TO THE SOUTHWEST OF THE REGION AND THIS WILL
SUPPORT THE TRANSPORT OF MOISTURE TROPICAL AIR INTO THE REGION.
MEANWHILE IN EL SALVADOR, THERE WILL BE A RISK FOR SEVERE WEATHER
ON FRIDAY. OVERALL, EXPECT DAILY LIGHT TOTAL PRECIPITATION MAXIMA
FOR THE NEXT THREE DAYS IN THIS REGION.
ACROSS THE REST OF CENTRAL AMERICA AND TROPICAL SOUTH AMERICA...
ON THURSDAY, WIDESPREAD CYCLONIC CIRCULATION WILL BE OBSERVED IN
THE LOW LEVELS ACROSS THE SOUTHWEST CARIBBEAN SEA AND ALONG THE
PACIFIC COASTS OF COSTA RICA, PANAMA, AND COLOMBIA. EXPECT A LONG
FETCH MOISTURE TONGUE TO CONVERGE INTO THE NORTH-CENTRAL PACIFIC
COAST OF COLOMBIA. MEANWHILE IN THE CARIBBEAN, EASTERLY LOW LEVEL
WINDS WILL DOMINATE AND LEAD TO MOISTURE POOLING AND MOISTURE
CONVERGENCE ALONG THE COASTS OF SOUTHERN NICARAGUA, COSTA RICA,
AND PANAMA. ELEVATED PRECIPITATION ACCUMULATIONS ARE LIKELY ACROSS
COLOMBIA AND MODERATE ACCUMULATIONS ARE LIKELY ACROSS NICARAGUA,
COSTA RICA, AND PANAMA.
BY FRIDAY, THE AREA WITH THE MOST INTENSE MOISTURE CONVERGENCE
WILL SHIFT INTO NICARAGUA AND FAR WESTERN HONDURAS, YIELDING
MODERATE TOTAL PRECIPITATION MAXIMA. MEANWHILE, A TROPICAL WAVE
WILL BE MOVING ACROSS PANAMA AND WILL SUPPORT VORTICITY IN THE
REGION. MODERATE TOTAL PRECIPITATION MAXIMA IS LIKELY IN THE
PROXIMITY OF THIS WAVE ON FRIDAY. ON SATURDAY, THE TROPICAL WAVE
WILL BE MOVING ACROSS THE SOUTHEAST CARIBBEAN SEA AND WILL ARRIVE
INTO NORTHEAST NICARAGUA ON SATURDAY EVENING. THUS, ENHANCED
ACCUMULATIONS ARE LIKELY IN THIS REGION DUE TO THE PRESENCE OF THE
TROPICAL WAVE. ALONG PANAMA AND THE PACIFIC COAST OF COLOMBIA, THE
LOW LEVEL WIND FLOW WILL BECOME LESS ORTHOGONAL TO THE LOCAL
TOPOGRAPHY AND WIND SPEEDS WILL DECREASE. THUS, THE HIGHEST
PRECIPITATION ACCUMULATIONS ARE EXPECTED FOR THURSDAY AND FRIDAY.
ACROSS TROPICAL SOUTH AMERICA, EXPECT THE PROPAGATION OF LOW LEVEL
TROUGHS AND TROPICAL WAVES FOR THE NEXT THREE DAYS. THE FIRST
TROPICAL WAVE IS CURRENTLY ACROSS COLOMBIA AND WILL CONTINUE TO
MOVE ACROSS THE ANDES ON THURSDAY AND FRIDAY. BY FRIDAY EVENING,
THE TROPICAL WAVE AXIS WILL BE NEAR CENTRAL PANAMA AND BY SATURDAY
EVENING, IT WILL BE APPROACHING COSTA RICA BEFORE REACHING
NICARAGUA ON SATURDAY EVENING. THE SECOND TROPICAL WAVE IS
CURRENTLY ACROSS GUYANA AND WILL CONTINUE TO MOVE ACROSS VENEZUELA
ON FRIDAY BEFORE ARRIVING INTO COLOMBIA ON FRIDAY. THESE TWO
FEATURES WILL DRIVE PRECIPITATION IMPACTS IN THE AREA, LEADING TO
ENHANCED TOTAL PRECIPITATION MAXIMA FOR THE NEXT THREE DAYS. IN
GENERAL, THE REGION WILL REMAIN VERY MOIST AND LOCALIZED SHOWERS
AND THUNDERSTORMS ARE LIKELY FOR THE NEXT THREE DAYS.
IN THE CARIBBEAN, A BROAD RIDGING PATTERN WILL DEVELOP ACROSS THE
GREATER ANTILLES AND WILL DRIVE THE TRANSPORT OF MOIST AIR INTO
CUBA AND THE BAHAMAS. MODERATE ACCUMULATIONS ARE LIKELY WITH THIS
PATTERN ACROSS CUBA FOR THE NEXT THREE DAYS. ACROSS THE REST OF
THE REGION, EXPECT THE PRESENCE OF WEAK MOISTURE PLUMES TO
CONTINUE TO PROPAGATE ACROSS THE BASIN. HOWEVER, THERE IS
CURRENTLY A SAHARAN AIR LAYER PLUME APPROACHING THE CARIBBEAN,
WHICH WILL ACT AS A SUPPRESSOR OF PRECIPITATION INITIATION FOR THE
END OF THE WEEKEND.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
TYP SOF INIT 29/00 29/12 30/00 30/12 31/00 31/12 01/00 01/12
TW 09N 42W 45W 48W 52W 56W 59W 62W 65W 67W
TW 05N 58W 61W 63W 66W 69W 71W 74W 77W 80W
TW 09N 69W 71W 74W 76W 79W 81W 83W 85W 88W
TW 14N 82W 84W 86W DISS --- --- --- --- ---
TW 12N 99W 101W DISS --- --- --- --- --- ---
TINOCO-MORALES...(WPC)
SANCHEZ-PEREZ...(WPC)
MURRAY...(MSJ)
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