371
FXCA20 KWBC 311650
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1149 AM EST FRI JAN 31 2025
FORECAST BULLETIN 31 JANUARY 2025 AT 16:50 UTC
..LARGE SCALE CONDITIONS
THE MJO CONTINUES PROPAGATING IN PHASE 4...WHICH IMPLIES ENHANCED
UPPER CONVERGENCE IN THE AMERICAS. EMBEDDED IN THIS UPPER
CONVERGENT PATTERN...A POTENTIAL KELVIN WAVE IS FORECAST TO ENTER
THE AMERICAS EARLY NEXT WEEK. THERE IS MODEL AGREEMENT ON A
DECREASE IN LARGE SCALE UPPER CONVERGENCE...WHICH WILL LIKELY
RESULT IN A GENERALIZED WEAKENING OF THE TRADE WIND CAP AND AN
INCREASE IN THE COVERAGE OF AREAS PRONE TO THE DEVELOPMENT OF DEEP
CONVECTION.
..FRONT IN MEXICO ON FRIDAY AND SATURDAY
A SURFACE FRONT IS PROPAGATING FROM FLORIDA ACROSS THE GULF AND
THE VERACRUZ REGION. BY FRIDAY EVENING IT IS ANALYZED ACROSS THE
FLORIDA PANHANDLE...CENTRAL GULF...SOUTHERN VERACRUZ. BY SATURDAY
EVENING IT IS FORECAST ACROSS CENTRAL FLORIDA...CENTRAL GULF INTO
EASTERN TABASCO AND SOUTHEAST CHIAPAS. THE FRONT IS FORECAST TO
RAPIDLY WEAKEN THEREAFTER AND RETREAT NORTHWARD AS A STATIONARY
BOUNDARY. BY SUNDAY EVENING EXPECT A WEAKENING BOUNDARY ACROSS
CENTRAL FLORIDA...CENTRAL GULF. PRECIPITATION IMPACTS: A NORTES
EVENT ON FRIDAY WILL FAVOR MAXIMA OF 20 - 35MM IN NORTHERN OAXACA
AND SOUTHERN VERACRUZ DUE TO TERRAIN ENHANCEMENT. ALSO...EXPECT
THUNDERSTORMS ALONG A PREFRONTAL TROUGH IN THE WESTERN YUCATAN
PENINSULA/CAMPECHE/NORTHERN GUATEMALA AND EASTERN CHIAPAS TO FAVOR
ISOLATED MAXIMA OF 15 - 20MM. EXPECT A PEAK IN PRECIPITATION ON
SATURDAY IN TABASCO/CHIAPAS WHERE EXPECT MAXIMA OF 20 - 45MM DUE
TO TERRAIN ENHANCEMENT. IN GUATEMALA AND BELIZE EXPECT 05 -
10MM/DAY AND ISOLATED MAXIMA OF 15 - 20MM.
..CLOSED UPPER LOW IN CENTRAL MEXICO ON SUNDAY
AN UPPER TROUGH CURRENTLY IN NORTHWEST MEXICO IS FORECAST TO
SEGREGATE FROM THE WESTERLIES AND FORM A CUTOFF LOW OVER CENTRAL
MEXICO DURING SATURDAY INTO SUNDAY. 500 HPA TEMPERATURES ARE
FORECAST TO DECREASE UNDER -15C...SETTING UP A HIGHLY UNSTABLE
ENVIRONMENT ESPECIALLY OVER EASTERN PORTIONS OF THE EJE VOLCANICO
CENTRAL AND SIERRA MADRE ORIENTAL SUR...INCLUDING MEXICO CITY.
ALTHOUGH MOISTURE IS OFTEN LIMITED THIS TIME OF THE YEAR...IT WILL
BE SUFFICIENT TO TRIGGER SCATTERED STRONG THUNDERSTORMS...SOME
CAPABLE OF PRODUCING SMALL HAIL. EXPECT MAXIMA GENERALLY UNDER
15MM.
..CARIBBEAN BASIN
MID LEVELS: THE SEASONAL MID-LEVEL RIDGE IS PRESENT WHILE
CENTERING OVER THE NORTHWEST BAHAMAS ON FRIDAY AND EXTENDING OVER
MOST OF THE CARIBBEAN. THE RIDGE ASSOCIATES WITH A TRADE WIND
INVERSION OVER THE ENTIRE CARIBBEAN...ALTHOUGH WEAKNESSES ARE
PRESENT IN ASSOCIATION WITH A LOW-LEVEL TROUGH PROPAGATING
WESTWARD ACROSS EASTERN HISPANIOLA...AND ACROSS THE WINDWARD
ISLANDS. THE RIDGE IS FORECAST TO GRADUALLY WEAKEN...PARTLY IN
RESPONSE TO THE DECREASE IN UPPER CONVERGENCE. THIS WILL YIELD TO
A GRADUAL DECREASE IN STABILITY AND WEAKENING OF THE TRADE WIND
INVERSION INTO NEXT WEEK. FURTHERMORE...A TUTT IS EXPECTED TO
PROPAGATE WESTWARD ACROSS THE TROPICAL ATLANTIC TO ARRIVE IN THE
WINDWARD ISLANDS ON SUNDAY. THIS WILL ENHANCE THE VERTICAL
DEVELOPMENT OF CONVECTION AND ACCUMULATIONS. IN THE LOWER
LEVELS...THE TRADES CONTINUE ACCELERATED...FAVORING ENHANCED WIND
SHEAR AND LIMITING THE RESIDENCE TIME OF PRECIPITATING CONVECTION.
PRECIPITATION WILL GENERALLY PEAK IN REGIONS OF ENHANCED TRADE
WIND CONVERGENCE AND TERRAIN ENHANCEMENT IN EASTERN SLOPES.
PRECIPITATION AMOUNTS: ON FRIDAY EXPECT THE LARGEST ACCUMULATIONS
IN THE LESSER ANTILLES AND IN THE DOMINICAN REPUBLIC WHERE EXPECT
MAXIMA GENERALLY UNDER 15MM. ON SATURDAY A TROUGH IN THE LEEWARD
ISLANDS AND MARTINIQUE WILL FAVOR 05 - 10MM/DAY AND ISOLATED
MAXIMA OF 15 - 20MM IN ELEVATED TERRAIN. ON SUNDAY EXPECT MAXIMA
OF 15MM IN MOST OF THE CENTRAL LESSER ANTILLES AND WINDWARD
ISLANDS DUE TO AN ARRIVING TROUGH IN THE TRADES AND THE TUTT. IN
HISPANIOLA...A LOW-LEVEL TROUGH WILL FAVOR 05 - 10MM/DAY AND
MAXIMA OF 15 - 25MM.
..CENTRAL AMERICA
THE ENHANCED EASTERLY TRADES AND CARIBBEAN LOW-LEVEL JET WILL
FAVOR INTERMITTENT SHOWERS IN THE CARIBBEAN BASINS OF COSTA
RICA/SOUTHERN NICARAGUA AND WEST PANAMA. NOTICE HOWEVER A
PROMINENT DECREASE IN PRECIPITABLE WATER AS THE CYCLE
PROGRESSES...WHICH WILL YIELD TO A DECREASE IN ACCUMULATIONS. THE
LARGEST AMOUNTS ARE EXPECTED THROUGH EARLY SATURDAY WHEN EXPECT
MAXIMA OF 30 - 60MM. ON SATURDAY THIS DECREASES TO MAXIMA OF 20 -
35MM IN PANAMA AND MAXIMA OF 15 - 20MM IN NORTHERN COSTA
RICA/SOUTHEAST NICARAGUA. EXPECT AN ADDITIONAL DECREASE
THEREAFTER. NOTE THAT VERY ISOLATED HIGHER AMOUNTS ARE LIKELY
UNDER THIS WEATHER PATTERN DUE TO TERRAIN ENHANCEMENT.
..NORTHERN SOUTH AMERICA
DECELERATING UPPER WESTERLY FLOW ACROSS THE PACIFIC BASIN INTO
COLOMBIA/ECUADOR CONTINUES ENHANCING UPPER CONVERGENCE...YIELDING
TO LIMITED COVERAGE OF DIURNAL DEEP CONVECTION.
NEVERTHELESS...ONSHORE FLOW ALONG AND SOUTH OF THE ITCZ CONTINUES
STIMULATING CONVECTION IN THE PACIFIC BASINS OF COLOMBIA AND
ECUADOR ON A DAILY BASIS. AN INCREASE IN WESTERLY LOW-LEVEL WINDS
AND PRECIPITABLE WATER ON SUNDAY WILL FAVOR A NOTICEABLE PEAK IN
PRECIPITATION PARTICULARLY IN ECUADOR. THROUGH EARLY SATURDAY
EXPECT THE LARGEST ACCUMULATIONS MOSTLY IN WESTERN COLOMBIA WHERE
EXPECT 15 - 20MM/DAY AND ISOLATED MAXIMA OF 25 - 50MM. ON SATURDAY
EXPECT MAXIMA OF 20 - 40MM FROM FAR NORTHWEST ECUADOR INTO
SOUTHWEST COLOMBIA. ON SUNDAY EXPECT EVENING HEAVY THUNDERSTORMS
IN COASTAL ECUADOR AND SOUTHWEST COLOMBIA WITH FORECAST MAXIMA IN
THE 35 - 70MM RANGE. IN THE GUIANAS...EXPECT GENERALLY FAIR
WEATHER CONDITIONS AND LIGHT COASTAL SHOWERS DUE FAST
NORTHEASTERLY TRADES AND ENHANCED LOW-LEVEL WIND SHEAR. A MOIST
PLUME IS MOVING IN FROM THE EQUATORIAL INTO FRENCH GUIANA AND
EASTERN SURINAME ON SUNDAY...WHICH WILL FAVOR THUNDERSTORMS WITH
POTENTIAL MAXIMA OF 20 - 35MM.
GALVEZ...(WPC
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