871
FXCA20 KWBC 091840
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
239 PM EDT MON MAR 09 2026
FORECAST BULLETIN 09 MARCH 2026 AT 1840 UTC:
OVER MEXICO AND NORTHERN CENTRAL AMERICA, A MID TO UPPER LEVEL
TROUGH WITH A CLOSED LOW IS ENTERING THE BAJA CALIFORNIA PENINSULA
ON MONDAY MORNING, ACCOMPANIED BY A LOW PRESSURE SYSTEM IN THE
LOWER LEVELS FAVORING MOIST ONSHORE FLOW INTO THE BAJA CALIFORNIA
REGION BY MONDAY EVENING. THIS MOIST ONSHORE FLOW IS EXPECTED TO
ENTER WEST SONORA AS THE SYSTEM PROPAGATES EAST BY EARLY TUESDAY
MORNING. TO THE SOUTH OVER SOUTHERN MEXICO AND NORTHERN CENTRAL
AMERICA, A RIDGING PATTERN IS EXPECTED IN THE UPPER LEVELS, WHILE
A RIDGE DOMINATES THE REGION IN THE MID LEVELS, FAVORING TRADE
WIND INVERSION CAPS LOCATED BETWEEN THE 900-750HPA LEVELS. IN
ADDITION TO THESE INVERSIONS, EXPECT DRIER AIR OVER THESE REGIONS,
LIMITING CONVECTION. WITH THE PRESENCE OF THE TWO SYSTEMS OVER
MEXICO, EXPECT AN AREA OF ENHANCED DIVERGENCE AT THE POINT WHERE
THEY INTERACT, OVER THE BAJA CALIFORNIA PENINSULA AND NORTHWEST
MEXICO ON MONDAY, WHERE EXPECT MAXIMA OF 20-35MM WITH A SLIGHT
RISK OF SEVERE WEATHER IN SONORA, AND MAXIMA OF 15-20MM WITH A
MARGINAL RISK OF SEVERE WEATHER IN THE CENTRAL BAJA CALIFORNIA
PENINSULA. BY TUESDAY EVENING, THE MID TO UPPER LEVEL TROUGH
PROPAGATES INTO THE SOUTH-CENTRAL UNITED STATES AND ITS BASE
EXTENDS OVER WESTERN MEXICO. SIMILARLY, THE MID TO UPPER LEVEL
RIDGE ALSO SHIFTS EASTWARD, EXTENDING OVER THE WESTERN CARIBBEAN
AND REMAINING OVER NORTHER CENTRAL AMERICA BY TUESDAY EVENING. A
SHORTWAVE MID TO UPPER LEVEL TROUGH EXTENDS INTO THE NORTHERN
MEXICAN PLATEAU,FAVORING A MARGINAL RISK OF SEVERE WEATHER OVER
THE REGION. HOWEVER, DUE TO THE LOW AVAILABLE MOISTURE ASSOCIATED
WITH THE SYSTEM, EXPECT MAXIMA OF 15MM. RESIDUAL MOISTURE ENTERING
SONORA FROM THE EASTERN PACIFIC WILL FAVOR MAXIMA OF 15-25MM. BY
WEDNESDAY EVENING, THE MID TO UPPER LEVEL TROUGH HAS ENTERED THE
SOUTHEASTERN UNITED STATES, WHERE A PREFRONTAL TROUGH IS EXPECTED
TO REACH TAMAULIPAS. WITH THIS, EXPECT TRACE AMOUNTS OF
PRECIPITATION ON WEDNESDAY.
OVER THE CARIBBEAN AND SOUTHERN CENTRAL AMERICA, A DEEP MID TO
UPPER LEVEL TROUGH EXTENDS OVER THE WEST CARIBBEAN, WITH ITS BASE
EXTENDING INTO COSTA RICA AND PANAMA BY THE MORNING HOURS OF
MONDAY. AS THIS SYSTEM IS EXPECTED TO REMAIN OVER THE REGION ON
MONDAY INTO TUESDAY, THE MID LEVEL TEMPERATURES WILL REACH BELOW
THE -8C THRESHOLD FOR SEVERE WEATHER IN THE NORTH CARIBBEAN, WHILE
MOIST PLUMES EMBEDDED IN THE TRADE WINDS ENTER THE GREATER
ANTILLES, FAVORING THUNDERSTORMS WITH LIGHT TO MODERATE
PRECIPITATION TOTALS ON MONDAY. THESE CONDITIONS ARE EXPECTED TO
CONTINUE INTO TUESDAY AND WEDNESDAY, AS THE MID TO UPPER TROUGH
MEANDERS EASTWARD INTO THE EAST CARIBBEAN. IN THE SOUTHERN SECTORS
OF CENTRAL AMERICA, CONTINUED MOIST ONSHORE FLOW ENHANCED BY THE
CARIBBEAN LOW LEVEL JET (LLJ) WILL FAVOR LIGHT PRECIPITATION OVER
CARIBBEAN COASTS OF PANAMA AND COSTA RICA, DUE TO THE LACK OF
HIGHER AMOUNTS OF MOISTURE IN THE REGION. IN TERMS OF
PRECIPITATION, EXPECT MAXIMA OF 25-50MM IN THE DOMINICAN REPUBLIC,
WHILE GENERALIZED MAXIMA OF 20-45MM IN EAST CUBA AND HAITI, WITH A
MARGINAL RISK OF SEVERE WEATHER. MOIST PLUMES ACROSS THE REGION
WILL FAVOR GENERALIZED MAXIMA OF 15-25MM OVER THE CARIBBEAN COASTS
OF CENTRAL AMERICA, AND OVER THE REST OF THE CARIBBEAN REGION. ON
TUESDAY, THE PRECIPITATION DECREASES IN THE REGION DUE TO A
DECREASE IN AVAILABLE MOISTURE. EXPECT GENERALIZED MAXIMA OF
15-25MM OVER THE GREATER ANTILLES. SIMILAR TOTALS ARE EXPECTED ON
WEDNESDAY.
OVER TROPICAL SOUTH AMERICA, THE BOLIVIAN HIGH IS CENTERED OVER
BOLIVIA AND EXTENDS NORTHWARD INTO THE SOUTHERN AMAZON BASIN,
WHERE IT BEGINS TO FAVOR DIFFLUENCE ALOFT FROM SOUTH COLOMBIA,
INTO ECUADOR, NORTH PERU, AND NORTHERN BRASIL. IN THE LOWER
LEVELS, THERE ARE MOIST TROUGHS THAT ARE EMBEDDED IN THE TRADE
WINDS THAT ARE PROPAGATING OVER THE AMAZON BASIN, ENCOUNTERING THE
DIFFLUENCE ALOFT FAVORING DEEP CONVECTION WITH THE DIURNAL CYCLE.
WITH AMPLE AVAILABLE MOISTURE, THERE ARE REGIONS OVER THE AMAZON
THAT COULD EXPECT LOCALIZED HIGHER AMOUNTS THAN THOSE FORECAST. BY
WEDNESDAY, EXPECT AN ADDITIONAL MOIST TROUGH TO APPROACH HE
GUIANAS AND THE AMAZON DELTA, WHERE MODERATE TO HEAVY
PRECIPITATION IS EXPECTED. IN TERMS OF PRECIPITATION, ON MONDAY,
EXPECT MAXIMA OF 30-60MM FROM WEST ECUADOR, THROUGH NORTH PERU
INTO THE CENTRAL AMAZON BASIN. GENERALIZED MAXIMA OF 20-45MM ARE
EXPECTED OVER THE EASTERN AMAZON INTO THE AMAZON DELTA, AS WELL AS
THE WESTERN COASTS OF COLOMBIA AND ECUADOR. BY TUESDAY, EXPECT
MAXIMA TO INCREASE OVER COASTAL FRENCH GUIANA INTO AMAPA-BRASIL,
WITH MAXIMA OF 25-50MM, WHILE SOUTHWEST COLOMBIA INTO NORTHERN
ECUADOR CAN EXPECT MAXIMA OF 30-60MM. BY WEDNESDAY, EXPECT MAXIMA
OF 25-50MM IN NORTHERN GUIANAS, WHILE THE REST OF THE REGION CAN
EXPECT MAXIMA OF 20-35MM IN THE WESTERN AMAZON BASIN, WHILE MAXIMA
OF 20-45MM ARE EXPECTED IN WESTERN ECUADOR.
CASTELLANOS...(WPC)
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