474
FXCA20 KWBC 171850
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
249 PM EDT WED JUN 17 2026
FORECAST BULLETIN 17 JUNE 2026 AT 1850 UTC:
ACROSS MEXICO...
A SHORTWAVE UPPER LEVEL TROUGH WILL BE GAINING DEFINITION DURING
THE DAY ON WEDNESDAY ACROSS NORTHWEST MEXICO AND ITS MID-LEVEL
PROJECTION WILL BECOME MORE APPARENT BY THURSDAY MORNING WHEN IT
WILL BE LOCATED ACROSS NORTHERN MEXICO. THIS PATTERN, COUPLED WITH
THE INTENSIFICATION OF A MID-TO-UPPER LEVEL RIDGE IN THE GULF FOR
THURSDAY WILL REINFORCE THE SUSTENANCE OF HIGH PRECIPITABLE WATER
VALUES ACROSS THE COASTLINE. THE MID-TO-UPPER LEVEL TROUGH AXIS
WILL ARRIVE INTO THE UNITED STATES SOUTHERN PLAINS ON THURSDAY
EVENING AND ITS BASE WILL EXTEND INTO NORTHERN MEXICO THROUGH THE
REST OF THE FORECAST CYCLE. UPPER DIFFLUENCE WILL BE PRESENT OVER
THE REGION, AND IT WILL MAINTAIN AREAS OF DIVERGENCE. WITH THE
DECREASE IN PRESSURE VALUES IN THIS REGION, EXPECT SOUTHERLY LOW
LEVEL WINDS TO STILL PREVAIL ACROSS NORTHEAST MEXICO.
PRECIPITATION CHANCES ARE THUS EXPECTED TO INCREASE ACROSS
CHIHUAHUA AND COAHUILA ON THURSDAY WITH THE ARRIVAL OF THE
MID-TO-UPPER TROUGH AXIS. ISOLATED SHOWERS AND THUNDERSTORMS ARE
LIKELY FOR THURSDAY, WHERE LIGHT TOTAL PRECIPITATION MAXIMA IS
EXPECTED. BY FRIDAY, THE AREA OF GREATEST PRECIPITATION IMPACT
WILL SHIFT TO THE EAST, INTO NUEVO LEON AND TAMAULIPAS WHERE
MODERATE TOTAL PRECIPITATION MAXIMA IS LIKELY.
MEANWHILE IN CENTRAL AND WESTERN MEXICO, THERE IS CURRENTLY WEAK
UPPER LEVEL SPEED DIVERGENCE PRESENT OVER CENTRAL MEXICO THAT WILL
BEGIN TO WEAKEN. IN ITS WAKE, EXPECT THE INTENSIFICATION OF AN
INVERTED UPPER LEVEL TROUGH DURING THE DAY ON WEDNESDAY, WHICH
WILL BE LOCATED ACROSS SOUTH-CENTRAL MEXICO. THIS UPPER TROUGH
WILL EXIT INTO THE PACIFIC OCEAN BY FRIDAY AFTERNOON. THE PRESENCE
OF THIS TROUGH WILL SUPPORT THE SUSTENANCE OF HIGH PRECIPITABLE
WATER VALUES IN THE REGION. AT THE SAME TIME, THERE WILL BE LOW
LEVEL ONSHORE FLOW (WESTERLY LOW LEVEL WINDS) INTO NAYARIT,
JALISCO, AND COLIMA. THOUGH THE LOW LEVEL WIND SPEEDS WILL BE
WEAK, STILL ANTICIPATE LOCAL AND OROGRAPHIC EFFECTS TO ASSIST IN
THE DEVELOPMENT AND SUSTENANCE OF SHOWERS AND THUNDERSTORMS. BY
FRIDAY, A MID-LEVEL SHORTWAVE TROUGH WILL BE DEVELOPING OVER
CENTRAL MEXICO THAT WILL PROVIDE AN ENHANCEMENT IN VERTICAL ASCENT
IN THE REGION. THIS MID-LEVEL TROUGH WILL BE PROPAGATING NORTHWARD
AND INFLUENCING THE SYNOPTIC CONDITIONS ACROSS NAYARIT AND
JALISCO.
MEANWHILE IN CENTRAL MEXICO, THE INTENSIFICATION OF THE MID-LEVEL
RIDGE WILL HELP TRANSPORT MOIST GULF AIR INTO THE REGION. ON THE
PACIFIC SIDE, THE PRESENCE OF WESTERLY LOW LEVEL WINDS ACROSS THE
WESTERN COAST WILL ALSO SUPPORT THE TRANSPORT OF MOISTURE INTO THE
INTERIOR OF THE COUNTRY. THUS, EXPECT AN INCREASE IN PRECIPITABLE
WATER VALUES. LIGHT TO MODERATE DAILY TOTAL PRECIPITATION MAXIMA
IS EXPECTED FOR THE CENTRAL REGION FOR WEDNESDAY AND THURSDAY AND
INCREASING IN MAGNITUDE FOR FRIDAY DUE TO THE PRESENCE OF THE
SHORTWAVE MID-LEVEL TROUGH.
IN CENTRAL AMERICA AND CHIAPAS/OAXACA, MEXICO...
CURRENTLY, A TROPICAL UPPER LEVEL TROUGH (TUTT) IS CURRENTLY OVER
THE CARIBBEAN. ITS AXIS EXTENDS FROM THE SOUTHERN BAHAMAS, INTO
SOUTHERN CUBA, AND WEST JAMAICA, WHILE ITS BASE IS LOCATED OVER
NICARAGUA AND HONDURAS. THE TUTT WILL BE RETROGRADING WITH PASSING
DAYS. BY FRIDAY EVENING, ITS CENTER WILL BE WELL DEFINED AND IT
WILL BE LOCATED ACROSS THE NORTHERN CARIBBEAN SEA. THUS, THIS
FEATURE WILL BE ASSISTING IN THE DEVELOPMENT OF A DIFFLUENT UPPER
LEVEL PATTERN ACROSS GUATEMALA AND SOUTHERN MEXICO FOR WEDNESDAY.
FOR THURSDAY AND FRIDAY, UPPER DIVERGENCE WILL BE MOST FAVORABLE
ACROSS PANAMA. MEANWHILE IN THE LOW TO MID-LEVELS, A TROPICAL WAVE
WILL BE MOVING ACROSS THE WEST CARIBBEAN SEA FOR THE NEXT THREE
DAYS, ASSISTING IN THE TRANSPORT OF MOIST AIR INTO THE REGION AND
ENHANCING CYCLONIC CIRCULATION. AT THE SAME TIME, THE CARIBBEAN
LOW LEVEL JET (CLLJ) WILL BE PRESENT IN THE REGION AND HELP
INCREASE THE PROPAGATION SPEED OF THE TROPICAL WAVE AS IT ENTERS
NICARAGUA ON THURSDAY. BY FRIDAY, THE TROPICAL WAVE AXIS WILL BE
ENTERING INTO THE PACIFIC OCEAN AND IT WILL BE INFLUENCING THE
PRECIPITATION REGIME ACROSS THE PACIFIC COASTS OF HONDURAS AND EL
SALVADOR. WITH RESPECT TO PRECIPITATION, THE HIGHEST TOTAL
PRECIPITATION MAXIMA OF THE REGION WILL BE LOCATED IN THE VICINITY
OF THE TROPICAL WAVE FOR THE NEXT THREE DAYS.
ANOTHER REGION OF INTEREST IS CHIAPAS/OAXACA, MEXICO AND
GUATEMALA, WHERE MOIST LOW LEVEL ONSHORE FLOW WILL BE PRESENT IN
THE REGION FOR WEDNESDAY AND THURSDAY. DURING THIS PERIOD, EXPECT
LIGHT TO MODERATE TOTAL PRECIPITATION MAXIMA. THEREAFTER, THIS
WIND FLOW WILL WEAKEN. HOWEVER, THE AFOREMENTIONED TROPICAL WAVE
WILL BE APPROACHING THE REGION AND IT WILL HELP WITH THE INCREASE
IN PRECIPITABLE WATER VALUES AND SOUTHWESTERLY LOW LEVEL WINDS
ALONG THE COASTS. THIS, COUPLED WITH A MID-TO-UPPER DIFFLUENT
PATTERN WILL HELP SUPPORT MODERATE TOTAL PRECIPITATION MAXIMA FOR
FRIDAY.
IN TROPICAL SOUTH AMERICA AND THE CARIBBEAN...
A SERIES OF LOW LEVEL TROUGH AND TROPICAL WAVES WILL BE
PROPAGATING ACROSS THE REGION FOR THE NEXT THREE DAYS. A TROPICAL
WAVE OF INTEREST IS CURRENTLY MOVING ACROSS THE GUIANAS AND IS
EXPECTED TO START ENTERING WESTERN VENEZUELA, TRINIDAD, AND TOBAGO
LATE WEDNESDAY EVENING AND EARLY THURSDAY MORNING. DURING THIS
PERIOD, EXPECT MOIST AIR ADVECTION ACROSS THE GUIANAS AND
EXTENDING INTO THE LESSER ANTILLES, WHICH WILL SUPPORT THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. PRECIPITATION CHANCES
WILL BEGIN TO INCREASE ON WEDNESDAY IN THE LESSER ANTILLES WITH
THE ARRIVAL OF THE MOISTURE PLUME. SHOWERS AND THUNDERSTORMS WILL
BE LIKELY THROUGH THURSDAY. MEANWHILE, THE TROPICAL WAVE WILL BE
MOVING ACROSS VENEZUELA ON THURSDAY AND FRIDAY. THE TROPICAL WAVE
WILL BE CROSSING THE ANDES IN COLOMBIA AFTER FRIDAY EVENING. THUS,
FOR THE NEXT THREE DAYS, EXPECT MODERATE TO ENHANCED TOTAL
PRECIPITATION MAXIMA IN THE VICINITY OF THE TROPICAL WAVE.
ANOTHER REGION OF INTEREST IS ALONG THE PACIFIC COASTS OF COLOMBIA
AND ECUADOR. THERE WILL BE HIGH PRECIPITABLE WATER VALUES IN THE
AREA, BUT THE LOW LEVEL WIND SPEEDS WILL BE WEAK. THE DIRECTION OF
THE LOW LEVEL WINDS WILL BE FROM A NORTHERLY AND NORTHWESTERLY
COMPONENT FOR THE NEXT THREE DAYS WHICH MAY SUPPORT OROGRAPHIC
EFFECTS. ANTICIPATE DAILY MODERATE TO ENHANCED TOTAL PRECIPITATION
MAXIMA THROUGH THE FORECAST CYCLE FOR THE REGION. IN THE GREATER
ANTILLES, A SERIES OF MOISTURE PLUMES AND INDUCED LOCAL TROUGHS
WILL SUPPORT THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN THE
REGION. FOR THE NEXT THREE DAYS, EXPECT LIGHT TOTAL PRECIPITATION
MAXIMA WITH THE PASSAGE OF THESE MOISTURE PLUMES.
TROPICAL WAVES:
SOF INIT 18/00 18/12 19/00 19/12 20/00 20/12 21/00 21/12
17N 29W 32W 36W 40W 43W 46W 49W 52W 56W
11N 53W 56W 59W 61W 63W 66W 70W 74W 77W
13N 76W 79W 82W 85W 88W 91W 94W 96W 99W
16N 84W 87W 89W 92W 94W 97W 100W 101W DISS
TINOCO-MORALES...(WPC)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page