Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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386 FXCA20 KWBC 071540 PMDCA TROPICAL DISCUSSION - INTERNATIONAL DESKS NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1040 AM EST FRI FEB 07 2025 FORECAST BULLETIN 7 FEBRUARY 2025 AT 18:00 UTC ...LARGE SCALE CONDITIONS... MJO: THE MJO IS EXPECTED TO CONTINUE LOSING ORGANIZATION AS IT APPROACHES PHASE 7 EARLY NEXT WEEK. ALTHOUGH THE MJO IS STILL IN PHASE 6 THE LARGE SCALE PATTERN IS ALREADY GRADUALLY BECOMING UPPER DIVERGENT WHICH IS CONSISTENT WITH THE WEAKENING OF THE EASTERLY TRADES IN SOME REGIONS AND A WEAKENING OF THE TRADE WIND STABLE LAYER. KELVIN WAVE: NONE SIGNIFICANT KELVIN WAVE APPROACHING THE CARIBBEAN BASIN. ENSO CONDITIONS: LA NINA THE WEATHER PATTERN HAS REMAINED GENERALLY STABLE... WITH TYPICAL LA NIA CONDITIONS PREVAILING THROUGHOUT THE ENTIRE BASIN THIS FEBRUARY. ...SYNOPTIC CONDITIONS IN THE CARIBBEAN BASIN... UPPER LEVELS: A WEAK UPPER-LEVEL TROUGH LOCATED OVER THE BAHAMAS AND TURKS AND CAICOS FROM SATURDAY INTO SUNDAY COULD ENHANCE INSTABILITY ALOFT. HOWEVER LIMITED IMPACTS ARE EXPECTED IN THE GREATER ANTILLES. MID-LEVELS: THE MID-LEVEL RIDGE IS ANTICIPATED TO PERSIST... FURTHER REINFORCING THE TRADE WIND INVERSION ACROSS THE ENTIRE CARIBBEAN SEA. ADDITIONALLY... DRY AIR AT THIS LEVEL CONTINUES TO DOMINATE THE CARIBBEAN BASIN. THIS SITUATION WILL PROMOTE FAIR CONDITIONS...LIMITING THE COVER OF LIGHT SHOWERS. LOWER LEVELS: A SURFACE HIGH PRESSURE SYSTEM WILL CONTINUE TO ADVANCE INTO THE WESTERN NORTH ATLANTIC... LEADING TO EAST-NORTHEAST WINDS IN THE GREATER ANTILLES FOR THE NEXT THREE DAYS. THIS... COMBINED WITH A SHALLOW MOISTURE PLUMES MOVING OVER THE GREATER ANTILLES... WILL PROMOTE LIGHT SHOWER ACTIVITY PRIMARILY IN THE NORTHERN AND EASTERN REGIONS OF PUERTO RICO AND THE DOMINICAN REPUBLIC ON SATURDAY AND SUNDAY. ...PRECIPITATION IN THE CARIBBEAN... THE FOLLOWING ISOLATED MAXIMA ARE EXPECTED: LESSER ANTILLES: MAXIMA OF 15 - 20MM ON FRIDAY...SATURDAY AND SUNDAY. DOMINICAN REPUBLIC: MAXIMA OF 10MM ON FRIDAY AND SATURDAY. EASTERN CUBA: MAXIMA OF 10MM ON FRIDAY. PUERTO RICO: A MAXIMA OF 10MM ON FRIDAY AND SATURDAY. ...CENTRAL AMERICA... THE MID-LEVEL RIDGE OVER THE BASIN WILL CONTINUE TO SUPPORT THE TRADE WINDS ACROSS THE CARIBBEAN SEA... FACILITATING THE TRANSPORT OF MOISTURE TO THE COAST OF CENTRAL AMERICA`S CARIBBEAN BASIN. THE AREAS OF PARTICULAR INTEREST INCLUDE NICARAGUA... NORTHEASTERN HONDURAS... BELIZE... AND THE WESTERN PART OF PANAMA. ...PRECIPITATION IN CENTRAL AMERICA... THE FOLLOWING MAXIMA ARE EXPECTED: BELIZE: MAXIMA IN THE RANGE OF 10 - 15 MM ON FRIDAY...SATURDAY AND SUNDAY EASTERN NICARAGUA: A MAXIMA 20-35MM ON FRIDAY. A MAXIMA 20 - 30MM ON SATURDAY AND SUNDAY. NORTHERN HONDURAS: MAXIMA OF 15-25MM ON FRIDAY...SATURDAY AND SUNDAY THE CARIBBEAN BASIN OF WEST PANAMA: A MAXIMA OF 15 - 25MM ON FRIDAY...SATURDAY AND SUNDAY. ...SYNOPTIC CONDITIONS OVER TROPICAL SOUTH AMERICA... OVERALL: THROUGH THE END OF THIS FORECAST CYCLE... WE WILL OBSERVE A TRANSITION PERIOD FROM UPPER CONVERGENT TO MORE UPPER DIVERGENT ALOFT...ASSOCIATED WITH THE STRENGTHENING OF THE BOLIVIAN HIGH. THIS WILL PROMOTE AND INCREASE IN THE COVERAGE OF DEEP CONVENTION DEVELOPMENT. CURRENTLY THE MID TO UPPER LEVELS ARE NOT PROVIDING ADEQUATE SUPPORT DUE TO STRONG WIND SHEAR AND UPPER CONVERGENCE. THE LOW LEVELS CONTINUE TO BE FAVORABLE FOR WARM CONVECTION AND ISOLATED SHOWERS ALONG THE INTERIOR COAST OF ECUADOR AND THE ANDES FROM FROM FRIDAY INTO SATURDAY. THIS IS DUE TO HIGH PRECIPITABLE WATER AND PERPENDICULAR ONSHORE FLOW. BY SUNDAY... INCREASING UPPER-LEVEL DIVERGENCE OVER WESTERN COLOMBIA IS EXPECTED TO PROMOTE ENHANCE DYNAMICALLY-INDUCED ASCENT AND FACILITATE THUNDERSTORM DEVELOPMENT. AS A RESULT... THE FOLLOWING MAXIMA ARE ANTICIPATED: NORTHERN AND COAST OF ECUADOR: A MAXIMA OF 20 - 35MM ON FRIDAY AND SATURDAY. A MAXIMA OF 20 - 45MM ON SUNDAY. SOUTHWEST COLOMBIA: A MAXIMA OF 20 - 35MM ON FRIDAY AND SATURDAY. AN MAXIMA OF 20 - 45MM ON SUNDAY. NORTHERN COLOMBIA: A MAXIMA OF 15 - 25MM ON FRIDAY AND SATURDAY. AN INCREASE BY SUNDAY WITH A MAXIMA OF 20 - 40MM. THE NOCTURNAL LOW-LEVEL JET OVER CENTRAL NORTHERN SOUTH AMERICA WILL CONTINUE TO WEAKEN... RESULTING IN A REDUCTION OF THE DRY AREAS AND AN INCREASE IN LIGHT RAINFALL ACROSS THE REGION. INCREASING UPPER-LEVEL DIVERGENCE... ALONG WITH THE MOISTURE PLUME MOVING OVER THE GUIANAS AND AMAPA... WILL FACILITATE AN INCREASE IN RAINFALL FROM FRIDAY TO SUNDAY... WITH THE HIGHEST AMOUNTS ANTICIPATED ON SUNDAY. ADDITIONALLY... THERE IS A RISK OF ECHO TRAINING ON SUNDAY. WET CONDITIONS IN THIS REGION ARE CHARACTERISTIC OF LA NIA CONDITIONS DURING FEBRUARY. THE FOLLOWING MAXIMA ARE ANTICIPATED: THE GUIANAS AND AMAPA: A MAXIMA OF 20 - 40MM ON FRIDAY AND SATURDAY. A MAXIMA OF 40 - 80 ON SUNDAY. TYPICAL PRECIPITATION MAXIMA ALONG THE ITCZ/NET OVER CONTINENTAL TROPICAL SOUTH AMERICA INDICATE AN ANTICIPATED INCREASE IN RAINFALL. UPPER LEVEL DIVERGENCE PROVIDES SUPPORT FOR DEEP CONVECTION DEVELOPMENT AND WILL FAVOR DAILY MAXIMA GENERALLY IN THE RANGE OF 20 TO 50 MM OVER THE COMING DAYS. FOR GRAPHICAL INFORMATION: HTTPS://WWW.WPC.NCEP.NOAA.GOV/INTERNATIONAL/CRB_DAY1-3.SHTML LEDESMA...(WPC) GALVEZ...(WPC $$