Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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908 FXCA20 KWBC 041933 PMDCA TROPICAL DISCUSSION - INTERNATIONAL DESKS NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 232 PM EST WED DEC 04 2024 FORECAST BULLETIN 04 DEC 2024 AT 1940 UTC: NOTE: LATEST DISCUSSION HAS A CORRECTION OF DATE. OVER THE NORTH CARIBBEAN AND SOUTHERN UNITED STATES...A MID TO UPPER LEVEL TROUGH EXTENDS INTO CUBA...AND THE GREATER ANTILLES. WHILE A MID TO UPPER LEVEL RIDGE IS STRENGTHENING ON WEDNESDAY OVER THE CARIBBEAN BASIN...EXTENDING INTO THE CENTRAL ATLANTIC...SOUTH MEXICO...CENTRAL AMERICA...AND NORTH SOUTH AMERICA. THE STRENGTHENING OF THE RIDGE IN THE UPPER LEVELS WILL BEGIN TO INTERFERE IN THE LOWER LEVELS WITH A FRONTAL BOUNDARY THAT IS EXPECTED OVER NORTH HISPANIOLA...JAMAICA...AND EXTENDS INTO NICARAGUA BY WEDNESDAY EVENING. A SHEAR LINE ASSOCIATED WITH THE FRONT EXTENDS OVER THE DOMINICAN REPUBLIC...AND NEAR THE SAN ANDRES AND PROVIDENCIA ISLANDS IN THE WEST CARIBBEAN SEA. DUE TO THE CONVERGENT CONDITIONS OF THE MJO DEEP CONVECTION IS LIMITED OVER THE MAJORITY OF THE REGION...HOWEVER THE PRESENCE OF AN ATMOSPHERIC KELVIN WAVE CAN ENHANCE CONVECTION WHERE CONDITIONS ARE FAVORABLE. THE HEAVIER TOTAL PRECIPITATION AMOUNTS ARE EXPECTED TO REMAIN ISOLATED OVER THE REGION ON WEDNESDAY. ON THURSDAY...THE FRONTAL BOUNDARY BEGINS MEANDERING NORTHWARD FROM TURKS AND CAICOS...EAST CUBA...AND INTO NORTH HONDURAS WHERE IT BEGINS TO BECOME STATIONARY AND WEAKEN. THE PREFRONTAL SHEAR LINE ALSO MOVES SLIGHTLY NORTHWESTWARD INTO THE WINDWARD PASSAGE AND JAMAICA...WHERE MODERATE PRECIPITATION IS EXPECTED. TO THE EAST...THE PRESENCE OF MOIST PLUMES ARE EXPECTED TO ARRIVE TO THE LESSER ANTILLES AND PROPAGATE WEST INTO THE SOUTHERN CARIBBEAN SEA ON FRIDAY. THESE MOIST PLUMES ARE INHIBITED FROM DEEPER CONVECTION DUE TO THE HIGH PRESSURE SYSTEM IN THE MID TO UPPER LEVELS SO MAXIMA ARE EXPECTED TO REMAIN BELOW 25MM IN THE LESSER ANTILLES ON THURSDAY AND FRIDAY...AND BELOW 35MM IN THE ABC ISLANDS AND EXTREME NORTH VENEZUELA. TO THE NORTH...A FAST MOVING FRONTAL BOUNDARY IN THE SOUTHERN UNITED STATES EXTENDS INTO NORTH MEXICO...WHERE THE MOIST AIR FROM THE GULF OF MEXICO IS ENTERING THE REGION OF TAMAULIPAS AND COAHUILA...WHERE THEY CAN EXPECT A MARGINAL RISK OF SEVERE WEATHER ON THURSDAY AND FRIDAY...AND MAXIMA BELOW 20MM ON BOTH DAYS. ON FRIDAY...THE FRONTAL BOUNDARY OVER THE SOUTH UNITED STATES EXTENDS INTO THE NORTH BAHAMAS...THE GULF OF MEXICO AND ENTERS THROUGH TEXAS. THE SECOND FRONTAL BOUNDARY OVER THE NORTH CARIBBEAN IS EXPECTED TO CONTINUE WEAKENING OVER TURKS AND CAICOS...CUBA...AND THE WEST CARIBBEAN...WHILE THE SHEAR LINE REMAINS PRESENT OVER HISPANIOLA. DUE TO THE NORTHEAST TRADE WINDS FAVORING OROGRAPHIC LIFT IN THE GOLF OF HONDURAS REGION...THE AREA CAN EXPECT HEAVY PRECIPITATION ON FRIDAY. IN SOUTH BAHAMAS...TURKS AND CAICOS...EAST CUBA...JAMAICA...AND HISPANIOLA EXPECT PRECIPITATION WITH THE PRESENCE OF THE WEAKENING FRONT AND THE SHEAR LINE. IN TERMS OF PRECIPITATION DUE TO THE FRONTAL BOUNDARY AND SHEAR LINE...NORTH COSTA RICA AND SOUTH NICARAGUA CAN EXPECT MAXIMA OF 35-70MM WITH A POTENTIAL FOR LOCALLY HIGHER AMOUNTS. SIMILAR AMOUNTS ARE EXPECTED IN NORTH HISPANIOLA. EAST HONDURAS...EAST NICARAGUA...AND JAMAICA CAN EXPECT MAXIMA OF 20-45MM. ON THURSDAY...NORTH HONDURAS CAN EXPECT MAXIMA OF 40-80MM...WHILE EXTREME EAST HONDURAS AND EAST NICARAGUA CAN EXPECT MAXIMA OF 30-60MM. THE SOUTH BAHAMAS...TURKS AND CAICOS...NORTH HISPANIOLA...EAST CUBA...AND JAMAICA CAN EXPECT MAXIMA OF 20-45MM. ON FRIDAY...THE GOLF OF HONDURAS REGION CAN EXPECT MAXIMA OF 40-80MM. SOUTH BAHAMAS...TURKS AND CAICOS...AND EAST CUBA CAN EXPECT MAXIMA OF 20-45MM. FROM EAST HONDURAS THROUGH EAST NICARAGUA EXPECT MAXIMA OF 20-35MM....THE JAMAICA AND HISPANIOLA CAN EXPECT MAXIMA OF 15-25MM. NORTH SOUTH AMERICA IS EXPECTED TO REMAIN ACTIVE IN THE CENTRAL PORTIONS OF THE CONTINENT...AS THE BOLIVIAN HIGH MEANDERS OVER THE REGION. THE PERIPHERY OF THE HIGH PRESSURE SYSTEM EXTENDS INTO NORTH SOUTH AMERICA WHERE VENTILATION IS EXPECTED OVER SOUTH COLOMBIA...AND NORTH BRASIL...EXTENDING INTO THE GUIANAS...AND NORTH PERU/WEST ECUADOR ON WEDNESDAY. AN INDUCED TROUGH PROPAGATING OVER NORTH BRASIL IS EXPECTED TO EFFECT THE SOUTHERN PORTION OF THE TROPICAL FORECAST REGION AND MODERATE PRECIPITATION IS EXPECTED...WITH THE POSSIBILITY OF LOCALLY HIGHER AMOUNTS OF PRECIPITATION OVER THE NEXT THREE DAYS. THE PRESENCE OF THE NOCTURNAL LOW LEVEL JETS IN COLOMBIA/VENEZUELA...AND THE GUIANAS ARE TRENDING TO DRIER CONDITIONS IN PORTIONS OF THE REGION. THESE CONDITIONS ARE EXPECTED FROM WEDNESDAY TO FRIDAY. THE PRESENCE OF THE ITCZ ENTERING FRENCH GUIANA AND AMAPA-BRASIL WILL FAVOR PERSISTENT PRECIPITATION OVER THE NEXT THREE DAYS...EXPECTED TO PRODUCE MODERATE PRECIPITATION. IN TERMS OF PRECIPITATION ON WEDNESDAY...AMAZONAS-BRASIL TO SOUTH COLOMBIA CAN EXPECT MAXIMA OF 30-60MM WITH HIGHER LOCAL AMOUNTS. WEST COLOMBIA AND AMAPA-BRASIL CAN EXPECT MAXIMA OF 20-45MM. ON THURSDAY...FROM SOUTH VENEZUELA/COLOMBIA...INTO AMAZONAS-BRASIL EXPECT MAXIMA OF 30-60MM...WITH A FRENCH GUIANA AND AMAPA EXPECTING MAXIMA OF 25-50MM. PARA-BRASIL AND EAST AMAZONAS-BRASIL CAN EXPECT MAXIMA OF 20-45MM. WEST COLOMBIA CAN EXPECT MAXIMA OF 20-45MM. ON FRIDAY...AMAPA...FRENCH GUIANA...AMAZONAS-BRASIL...AND WEST PARA CAN EXPECT MAXIMA OF 20-45MM. EASTERLY/TROPICAL WAVES INITIALIZED AT 12 UTC NONE CASTELLANOS...(WPC) $$