722
FXCA20 KWBC 271925
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
325 PM EDT WED MAY 27 2026
FORECAST BULLETIN 27 MAY 2026 AT 1930 UTC:
IN CUBA, MEXICO AND NORTH-CENTRAL CENTRAL AMERICA...
A DYNAMIC UPPER LEVEL PATTERN WILL BE AFFECTING SOUTHERN MEXICO
AND NORTH CENTRAL AMERICA FOR THE NEXT THREE DAYS. ON WEDNESDAY, A
SHORTWAVE TROUGH WILL BE PRESENT ACROSS THE YUCATAN PENINSULA AND
ITS BASE WILL EXTEND INTO 15.5N. DIFFLUENCE AND DIVERGENCE WILL BE
REINFORCED OVER THE YUCATAN PENINSULA, GUATEMALA, BELIZE, AND
NORTHWEST CUBA. THEREAFTER, THE TROUGH WILL BEGIN TO LOSE ITS
STRUCTURE ON THURSDAY, AND BY THURSDAY EVENING, ITS REMNANTS WILL
COMBINE WITH ANOTHER AMPLIFYING TROUGH TO THE NORTHWEST. WITH
RESPECT TO THE AMPLIFYING TROUGH, ON WEDNESDAY, IT WILL BEGIN TO
DEVELOP ACROSS NORTHEAST MEXICO AND ITS AMPLIFICATION WILL BE
SUPPORTED BY THE PRESENCE OF A POTENT JET STREAK MAX IN NORTHWEST
MEXICO. UPPER DIVERGENCE WILL BE PRESENT ACROSS ITS BASE AND EXIT
REGION, WHICH WILL BE LOCATED ACROSS TAMAULIPAS AND VERACRUZ FOR
WEDNESDAY. AS THIS TROUGH COMBINES WITH THE AFOREMENTIONED
WEAKENING UPPER TROUGH ON THURSDAY, EXPECT IT TO BEGIN TO INTERACT
WITH ANOTHER DEVELOPING RIDGE IN THE CARIBBEAN SEA. THIS WILL
CAUSE AN INCREASE IN WIND SPEEDS WHICH IN TURN WILL SUPPORT
DIVERGENCE FOR THURSDAY AND FRIDAY ACROSS THE SAME REGIONS.
IN TAMAULIPAS AND NORTHERN VERACRUZ, A SHORTWAVE MID-LEVEL TROUGH
WILL BE DEVELOPING ON WEDNESDAY AFTERNOON TO EVENING, WHICH WILL
FAVOR THE INCREASE IN INSTABILITY AND VERTICAL ASCENT. AT THE SAME
TIME, LOW LEVEL WIND SPEEDS WILL BE FROM THE SOUTHEAST, HELPING
TRANSPORT MOIST AIR INTO THE COAST AS WELL AS SUPPORTING MOISTURE
CONVERGENCE. MODERATE ACCUMULATIONS ARE LIKELY WITH THIS PATTERN
FOR WEDNESDAY AND A RISK FOR SEVERE WEATHER. DAILY PRECIPITATION
ACCUMULATIONS WILL DECREASE THEREAFTER.
AS THE PRESSURE LEVELS DECREASE IN THE SOUTH GULF, EXPECT THE
INCREASE IN MOISTURE ACROSS THE YUCATAN AND NORTH CENTRAL AMERICA.
FOR THE NEXT THREE DAYS, NUMEROUS LOW LEVEL TROUGHS WILL BE
DEVELOPING. AT THE SAME TIME, A TROPICAL WAVE WILL BE TRAVERSING
THE CARIBBEAN SEA ON WEDNESDAY AND THURSDAY BEFORE ARRIVING INTO
THE YUCATAN PENINSULA ON FRIDAY; HOWEVER, IT IS EXPECTED TO LOSE
ITS DEFINITION AS IT APPROACHES THE PENINSULA. THE SUSTENANCE OF
WIDESPREAD SOUTHEASTERLY AND EASTERLY LOW LEVEL WINDS INTO THE
REGION WILL SUPPORT OROGRAPHIC ENHANCEMENT IN NORTH-CENTRAL
GUATEMALA FOR THE NEXT THREE DAYS. ON WEDNESDAY, EXPECT MODERATE
PRECIPITATION ACCUMULATIONS IN THIS REGION. MEANWHILE ALONG THE
CARIBBEAN COAST OF NICARAGUA, ALSO EXPECT MODERATE PRECIPITATION
ACCUMULATIONS WITH THE APPROACH OF THE TROPICAL WAVE. BY THURSDAY,
MODERATE TO ENHANCED PRECIPITATION ACCUMULATIONS ARE EXPECTED
ALONG THE CARIBBEAN COASTS OF EASTERN HONDURAS AND NORTHERN
NICARAGUA, AGAIN AFFILIATED WITH THE TROPICAL WAVE. IN THE YUCATAN
PENINSULA AND GUATEMALA, A LOW LEVEL TROUGH WILL BE DEVELOPING IN
THE AFTERNOON AND EVENING. IT WILL SUPPORT THE ENHANCEMENT OF
CYCLONIC ROTATION AND MOISTURE CONVERGENCE. AT THE SAME TIME,
THERE WILL BE A MID-LEVEL SHORTWAVE TROUGH THAT WILL HELP
DESTABILIZE THE ENVIRONMENT. THESE CONDITIONS WILL FAVOR ENHANCED
PRECIPITATION ACCUMULATIONS IN THE REGION. ON FRIDAY, THE LOW
LEVEL WIND DIRECTION WILL BECOME MORE SOUTH-SOUTHEASTERLY, LEADING
TO THE DECREASE IN OROGRAPHIC EFFECTS IN THE YUCATAN PENINSULA.
ALSO AT THIS POINT, THE TROPICAL WAVE WILL BE DECAYING. THUS,
PRECIPITATION ACCUMULATIONS WILL BE ON THE MODERATE SIDE ACROSS
NORTH-CENTRAL GUATEMALA AND THE CARIBBEAN COAST OF BELIZE AND
QUINTANA ROO. THE PRECIPITATION THAT DOES DEVELOP WILL BE
CONCENTRATED IN THE VICINITY OF SURFACE TROUGHS. ALSO ON FRIDAY,
ANOTHER TROPICAL WAVE WILL BE APPROACHING THE CARIBBEAN COAST OF
NICARAGUA AND EASTERN BELIZE, BRINGING WITH AN INCREASE IN
MOISTURE AND AGAIN, CYCLONIC ROTATION. MODERATE PRECIPITATION
ACCUMULATIONS ARE EXPECTED WITH THIS FEATURE.
ELSEWHERE IN MEXICO, ACROSS THE CENTRAL REGION, THERE WILL BE A
SHORTWAVE MID-LEVEL TROUGH AND THE BASE OF AN UPPER TROUGH MOVING
ACROSS THE REGION EARLY THURSDAY MORNING, HELPING DESTABILIZE THE
ENVIRONMENT AND SUPPORTING DIVERGENCE. ALSO ON WEDNESDAY AND
THURSDAY, ONSHORE FLOW WILL BE PRESENT ALONG THE PACIFIC COASTS OF
GUERRERO AND OAXACA, WHICH WILL SUPPORT THE INFLUX OF MOISTURE
INTO THE HIGHER TERRAIN IN CENTRAL MEXICO. MODERATE ACCUMULATIONS
ARE EXPECTED WITH THESE CONDITIONS ON WEDNESDAY FOR CENTRAL MEXICO
AND LIGHT ACCUMULATIONS FOR THURSDAY. UPPER LEVEL SUPPORT WILL
DECREASE FOR FRIDAY.
ELSEWHERE IN CENTRAL AMERICA AND TROPICAL SOUTH AMERICA...
ACROSS COLOMBIA, EXPECT THE DEVELOPMENT OF ANOTHER LOW LEVEL
TROUGH STARTING ON WEDNESDAY. THIS TROUGH WILL SUPPORT THE BRIEF
INTENSIFICATION OF THE PANAMANIAN LOW LEVEL TROUGH, LEADING TO AN
INCREASE IN PRECIPITABLE WATER VALUES AND LOW LEVEL ONSHORE FLOW.
HOWEVER, WIND SPEEDS WILL BE WEAK FOR THIS PERIOD. THUS, EXPECT
MODERATE PRECIPITATION ACCUMULATIONS WITH THESE CONDITIONS FOR
WEDNESDAY. THEREAFTER, A LONG FETCH WESTERLY LOW LEVEL WIND FLOW
PATTERN WILL BE PRESENT FROM THE PACIFIC OCEAN AND INTO
NORTH-CENTRAL COLOMBIA, HELPING TRANSPORT DEEP MOISTURE INTO THE
REGION STARTING ON THURSDAY EVENING. THIS PATTERN WILL LEAD TO AN
INCREASE IN MOISTURE CONVERGENCE AND THUS PRECIPITATION
ACCUMULATIONS FOR THURSDAY.
EAST OF THE ANDES, A TROPICAL WAVE WILL CONTINUE TO MOVE ACROSS
THE GUIANAS AND INTO VENEZUELA TODAY. BY THURSDAY, THE TROPICAL
WAVE WILL BE TRAVERSING VENEZUELA AND ARRIVING INTO COLOMBIA FOR
FRIDAY. EXPECT THE ENHANCEMENT IN MOISTURE CONVERGENCE WITH THIS
FEATURE AND ENHANCED DAILY PRECIPITATION MAXIMA IN ITS VICINITY.
THE DECREASE IN PRESSURE VALUES ACROSS THE SOUTH CARIBBEAN SEA IS
SUPPORTING THE INCREASE IN EASTERLY AND SOUTHEASTERLY LOW LEVEL
WINDS ACROSS THE BASIN. ALSO, A REGION OF UPPER DIFFLUENCE WILL BE
PRESENT OVER SOUTHERN VENEZUELA, REINFORCING UPPER DIVERGENCE IN
THE REGION FOR WEDNESDAY. THUS, EXPECT THE MOST INTENSE
PRECIPITATION MAXIMA IN THE VICINITY OF LOW LEVEL TROUGHS/TROPICAL
WAVES AND AREAS WITH ENHANCED UPPER DIVERGENCE.
IN THE CARIBBEAN AND BAHAMAS...
A SERIES OF MOISTURE PLUMES WILL BE MOVING ACROSS THE REGION FOR
THE NEXT THREE DAYS. THEY WILL HELP INCREASE PRECIPITATION
CHANCES, ESPECIALLY IN COMBINATION WITH THE DIURNAL CYCLE AND
LOCAL EFFECTS. DAILY LIGHT PRECIPITATION ACCUMULATIONS ARE LIKELY
ACROSS THE ENTIRE REGION. IN THE BAHAMAS, A LOW LEVEL PRESSURE
SYSTEM WILL BE MOVING TO THE NORTHWEST STARTING ON THURSDAY AND
INTO FRIDAY, LEADING TO THE INFLUX OF MOISTURE INTO THE FAR
NORTHWEST ISLANDS. AT THE SAME TIME, THERE WILL BE SOME WEAK
MID-LEVEL TROUGHING THAT WILL HELP TRIGGER VERTICAL ASCENT AND
THUS INCREASE PRECIPITATION CHANCES. OVERALL, LIGHT ACCUMULATIONS
ARE LIKELY FOR THURSDAY AND FRIDAY WITH THE APPROACH OF THE
PRESSURE SYSTEM INTO THE REGION, THOUGH THE HIGHEST ACCUMULATIONS
WILL STAY OUT TO SEA.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
TYP SOF INIT 28/00 28/12 29/00 29/12 30/00 30/12 31/00 31/12
TW 09N 35W 38W 41W 44W 47W 50W 53W 56W 59W
TW 05N 50W 54W 57W 60W 63W 66W 69W 71W 74W
TW 14N 78W 80W 82W 85W 87W 89W DISS --- ---
TW 12N 95W 97W 99W 101W DISS --- --- --- ---
TINOCO-MORALES..(WPC)
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