587  
FXCA20 KWBC 201846  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
246 PM EDT MON MAR 20 2023  
 
FORECAST BULLETIN FROM 20 MAR 2023 AT 1845 UTC:A WEAKENING MJO  
PATTERN MAY START TO PLAY A ROLE IN THE GENERAL WEATHER PATTERN  
OVER THE TROPICS OVER THE COMING DAYS. THE LATEST MJO ANALYSIS AND  
GUIDANCE SUGGESTS THAT THERE IS LESS CONVECTIVE ENHANCEMENT  
EXPECTED THROUGH THE UPCOMING WEEK ACROSS THE TROPICS...WITH THE  
EXCEPTION PERHAPS OF THE WESTERN SECTIONS OF COLOMBIA AND ECUADOR  
WHERE A SLIGHT CONVECTIVE ENHANCEMENT MAY PREVAIL FOR THE FIRST  
HALF OF THIS WEEK...BUT IS EXPECTED TO BECOME LESS FAVORABLE LATER  
ON. MOST OF MEXICO WOULD BE IN MORE OF SUPPRESSED CONVECTIVE STATE  
FOR THE NEXT FEW DAYS...BUT THE SUPPRESSION WILL ALSO WEAKEN LATER  
ON IN THE WEEK. IN THE MID LEVELS...THERE IS A LOW PRESSURE ACROSS  
THE SOUTHEASTERN CARIBBEAN THAT WILL MEANDER IN THE AREA THROUGH  
THE FIRST HALF OF THE WORKWEEK...WHILE AN UPPER TROUGH WILL ALSO  
BE PRESENT OVER THE SOUTHEASTERN CARIBBEAN THROUGH THE SAME TIME  
PERIOD. THIS WILL CAUSE SCATTERED SHOWERS ACROSS THE LEEWARD  
ISLANDS FOR THE NEXT THREE DAYS. THERE IS CURRENTLY A COLD FRONT  
EXTENDING FROM THE CENTRAL ATLANTIC....THROUGH THE BAHAMAS AND  
CENTRAL CUBA...SOUTHWEST INTO THE GULF OF HONDURAS...WHERE IT  
BECOMES A STATIONARY FRONT THAT EXTENDS FROM HONDURAS AND  
BELIZE...NORTH INTO THE SOUTHERNMOST STATES OF MEXICO. THIS FRONT  
WILL CAUSE SIGNIFICANT SHOWER ACTIVITY FOR THE REST OF TODAY AND  
TONIGHT ACROSS NORTHERN CENTRAL AMERICA...SOUTHERN MEXICO...CUBA  
AND THE BAHAMAS. THE REST OF MEXICO IS EXPECTED TO REMAIN FAIRLY  
DRY...WITH THE EXCEPTION OF NORTHERN BAJA CALIFORNIA...WHERE A LOW  
PRESSURE SYSTEM WILL BRING SOME RAIN TO THE AREA TODAY AND ON  
TUESDAY...CONDITIONS IMPROVING BY WEDNESDAY. THE CONVECTION ACROSS  
NORTHERN SOUTH AMERICA IS EXPECTED TO BE MAINLY ACROSS NORTH  
CENTRAL BRAZIL AND ALONG THE WESTERN SECTIONS FROM NORTHERN PERU  
INTO COLOMBIA...WHILE THE GUIANAS WILL RECEIVE SOME RAINFALL IN  
ISOLATED AREAS. TUESDAY LOOKS LIKE THE RAINIEST DAY COMPARED TO  
TODAY AND WEDNESDAY.  
 
IN TERMS OF AMOUNTS OF RAINFALL...THE FRONTAL BOUNDARY WILL CAUSE  
RAINFALL IN THE ORDER OF 10-15MM/DAY OR SO WITH MAXIMAS THAT COULD  
REACH 25-30MM ACROSS THE GREATER ANTILLES AND NORTHERN BAHAMAS  
TODAY. NORTHERN CENTRAL AMERICA AND SOUTHERNMOST MEXICO MAY SEE  
SIMILAR AMOUNTS OF RAIN WITH TOTALS BETWEEN 10-15 MM/DAY...BUT  
WITH MAXIMAS BETWEEN 25-45MM. FOR TUESDAY...AS THE FRONT MOVES  
SOUTH SLOWLY...THE HIGHER RAINFALL AMOUNTS WILL ALSO BE EXPECTED  
FURTHER SOUTH. NOW IT IS THE SOUTHERN BAHAMAS AND SOUTHERN CUBA AS  
WELL AS JAMAICA AND SOUTHERN HAITI. THAT WILL RECEIVE THE HIGHER  
AMOUNT OF RAIN WITH TOTALS NEAR 05-10MM/DAY WITH MAX NEAR 15-25MM.  
NORTHERN CENTRAL AMERICA AND SOUTHERN MEXICO WILL CONTINUE TO  
OBSERVE SIGNIFICANT RAINFALL...THOUGH A BIT MORE  
GENERALIZED...WITH OVERALL RAINFALL VALUES OF 05-10MM/DAY MAX  
VALUES BETWEEN 15-25MM...WHILE PORTIONS OF HONDURAS...SOUTHERN  
MEXICO...AND BELIZE COULD OBSERVE MAX VALUES SOMEWHERE BETWEEN  
25-45MM. BY WEDNESDAY...THE COLD FRONT WEAKENS  
SIGNIFICANTLY...AND MAINLY ISOLATED AREAS EXPECTED TO RECEIVE  
SIGNIFICANT RAINFALL. 05-10MM/DAY WITH MAX SOMEWHERE BETWEEN 15  
AND 25MM CAN BE EXPECTED ACROSS PORTIONS OF THE GREATER ANTILLES.  
NORTHERN CENTRAL AMERICA AND SOUTHERN MEXICO WILL OBSERVE BETWEEN  
05-10MM WITH MAX BETWEEN 15 AND 25MM. THE REST OF CENTRAL AMERICA  
WILL ALSO RECEIVE SOME RAIN...ESPECIALLY ACROSS COSTA RICA AND  
PANAMA...WITH TOTALS GENERALLY BETWEEN 05-15MM/DAY AND MAXIMAS  
SOMEWHERE BETWEEN 15-30MM EACH DAY...ALTHOUGH TUESDAY LOOKS LIKE  
THE RAINIEST DAY. THE LEEWARD ISLANDS ARE IN THE SAME PLACE...WITH  
RAINFALL TOTALS ACROSS THE LEEWARDS RANGING BETWEEN 05-10MM/DAY  
TODAY AND TUESDAY WITH MAX UP TO 25MM...BUT 15-20MM/DAY WITH  
MAXIMA UP TO 40MM CAN BE EXPECTED ON WEDNESDAY.  
 
ACROSS NORTHERN SOUTH AMERICA...THE MOST PERSISTENT RAINFALL OVER  
THE NEXT THREE DAYS WILL BE ACROSS ECUADOR...WESTERN COLOMBIA AND  
PORTIONS OF NORTH CENTRAL BRASIL. THIS IS THE CASE GENERALLY DUE  
TO CONVECTION ACROSS THE AREA. BUT A SIGNIFICANT PORTION OF  
NORTHERN SOUTH AMERICA WILL REMAIN RAIN FREE. ECUADOR AND WESTERN  
COLOMBIA WILL OBSERVE PERIODS OF THUNDERSTORMS...AND THE RAINFALL  
TOTALS COULD BE NEAR 10-15MM/DAY WITH MAXIMAS BETWEEN 25-35MM FOR  
THE NEXT THREE DAYS...BUT A SMALL PORTION OF NORTHWESTERN ECUADOR  
AND SOUTHWESTERN COLOMBIA COULD OBSERVE AS MUCH AS 15-20MM WITH  
MAXIMAS OF 25-50MM ON WEDNESDAY. THE AMAZONAS STATE IN BRAZIL EAST  
INTO THE GUIANAS WILL OBSERVE GENERALLY 05-15MM/DAY WITH MAXIMAS  
BETWEEN 15 AND 35MM EACH DAY FOR THE NEXT THREE DAYS...WITH THE  
HIGHER AMOUNTS IN THAT RANGE BEING FORECAST ALONG THE NET IN  
BRAZIL.  
 
ALAMO/ACOSTA...WPC (USA)  
 

 
 
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