809
FXCA20 KWBC 302014
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
314 PM EST MON DEC 30 2024
FORECAST BULLETIN 30 DEC 2024 AT 20 UTC:
THE MADDEN-JULIAN OSCILLATION (MJO) REMAINS IN ITS DIVERGENT PHASE
THROUGH THE WEEK. WIDESPREAD CONVECTION IS MORE FAVORABLE IN
REGIONS WHERE SYNOPTIC FORCING WILL OCCUR.
A COLD FRONT WILL BE DEVELOPING IN THE CENTRAL USA AND QUICKLY
MOVING SOUTHWARD. BY TUESDAY EVENING ... IT WILL BE LOCATED ALONG
THE NORTHERN EXTREMES OF THE GULF OF MEXICO AND NORTHERN FLORIDA
... BY WEDNESDAY EVENING IT IS EXPECTED ALONG THE NORTHERN BAHAMAS
.. CENTRAL GULF OF MEXICO
MOUTH OF THE RIO BRAVO. THIS COLD
FRONT WILL HAVE MINIMAL IMPACTS IN THE REGION IN TERMS OF
RAINFALL. ELSEWHERE...AN ELONGATED COLD FRONT CURRENTLY EXTENDS
FROM A LOW IN THE NORTH ATLANTIC INTO THE WINDWARD ISLANDS. DUE TO
A DECREASE IN BAROCLINICITY...IT IS BEING ANALYZED AS A SHEARLINE
ACROSS THE SOUTHERN CARIBBEAN. THIS SHEAR LINE AND A SECOND ONE
EXTENDING INTO GUYANA ON MONDAY WILL MAINLY INFLUENCE
PRECIPITATION IN TRINIDAD AND TOBAGO AND THE GUIANAS THROUGH THE
CYCLE. EXPECT THE ITCZ TO ALSO PLAY A ROLE IN INFLUENCING THE
PRECIPITATION PATTERNS IN THE GUIANAS ON A DAILY BASIS FOR THE
NEXT THREE DAYS.
IN UPPER LEVELS OF NORTHERN CENTRAL AMERICA AND THE YUCATAN
PENINSULA...EXPECT ENHANCED DIVERGENCE DUE SPEED DIFFLUENCE IN THE
NORTHERN TIER OF AN UNUSUALLY ROBUST SUBEQUATORIAL RIDGE. THE
HIGHEST IMPACT IS EXPECTED ON WEDNESDAY...WHEN A COMBINATION OF
THIS UPPER LEVEL DIVERGENCE...LOW LEVEL MOISTURE ADVECTION FROM
THE CARIBBEAN SEA...AND A PROPAGATING LOW LEVEL TROUGH WILL HELP
ENHANCE PRECIPITATION CHANCES...ESPECIALLY ALONG THE CARIBBEAN
COASTS. EXPECT RAINFALL MAXIMA OF 15 - 30MM/DAY TUESDAY AND
WEDNESDAY FOR REGIONS OF GUATEMALA...EL
SALVADOR...HONDURAS...BELIZE...AND QUINTANA ROO. ON
WEDNESDAY...EXPECT LOCALLY HIGHER AMOUNTS IN THE CARIBBEAN BASIN
OF CENTRAL GUATEMALA WHERE MAXIMA COULD REACH 25-50MM/DAY.
IN NICARAGUA AND PANAMA...A LOW-TO-MID LEVEL HIGH PRESSURE SYSTEM
CENTERING JUST TO THE NORTH OF THE CAYMAN ISLANDS ON MONDAY
CONTINUES TO DRIVE EASTERLY TRADES IN THE CARIBBEAN BASIN AND
TRANSPORTING A MOIST PLUME INTO THE NICARAGUA...PANAMA...AND COSTA
RICA REGIONS THROUGH TUESDAY MORNING. AS THE HIGH PRESSURE SYSTEM
BROADENS INTO THE GULF OF MEXICO WITH THE PASSAGE THE
AFOREMENTIONED COLD FRONT ON WEDNESDAY...MOISTURE IS EXPECTED TO
INCREASE IN THE SOUTHWESTERN CARIBBEAN. RAINFALL MAXIMA OF 15 -
25MM WILL BE LIKELY IN THE CARIBBEAN COASTS OF NICARAGUA AND
PANAMA ON WEDNESDAY. INTERACTIONS WITH THE INTERTROPICAL
CONVERGENCE ZONE (ITCZ) WILL HELP TO INCREASE PRECIPITATION
CHANCES TODAY INTO TUESDAY...WITH A RAINFALL MAXIMA OF 20 - 35MM
POSSIBLE ON THE PACIFIC COASTS OF COSTA RICA AND PANAMA.
TROPICAL SOUTH AMERICA...THE SUBEQUATORIAL UPPER JET WILL CONTINUE
TO INFLUENCE UPPER LEVEL DYNAMICS TODAY AND TUESDAY. BY
WEDNESDAY...THE JET IS FORECAST TO LOSE DEFINITION OVER THE
CONTINENT...WHICH GENERALLY FAVORS AN INCREASE IN RAINFALL
ACCUMULATION. WE EXPECT PRECIPITATION TOTALS TO INCREASE FOR
TUESDAY AND WEDNESDAY AS A RESULT. THE MJO WILL ALSO FAVOR MORE
WIDESPREAD CONVECTION IN THE REGION. THE BOLIVIAN HIGH ALSO
CONTINUES TO DOMINATE IN SOUTH AMERICA...ADDING ADDITIONAL
DIVERGENCE AND CONVECTIVE VENTILATION IN ITS PERIPHERIES. IN
COLOMBIA AND IN LOWER LEVELS...LONG FETCH WESTERLY FLOW FROM THE
PACIFIC BASIN WILL CONTINUE THROUGH THE FORECAST CYCLE...TO
HIGHLIGHT MOISTURE CONVERGENCE IN WESTERN PORTIONS OF THE COUNTRY.
RAINFALL TOTALSARE FORECAST TO PEAK ON TUESDAY WITH RAINFALL
MAXIMA OF 25 - 50MM/DAY POSSIBLE. BY WEDNESDAY...THE DEVELOPMENT
OF TWO LOW PRESSURE SYSTEMS IN THE PACIFIC WILL DISRUPT THE LONG
FETCH FLOW...YIELDING TO A DECREASE IN MAXIMA.
ELSEWHERE IN THE BASIN... EXPECT DIURNAL CONVECTION THROUGHOUT THE
REGION.
TINOCO...(WPC)
GALVEZ...(WPC)
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