526  
FXCA20 KWBC 211910  
PMDCA  
 
TROPICAL DISCUSSION - INTERNATIONAL DESKS  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
310 PM EDT FRI APR 21 2023  
 
FORECAST BULLETIN FROM 21 APR 2023 AT 1845 UTC: OF NOTE...THERE IS  
A DIVERGENT MJO PHASE AFFECTING A GOOD PORTIONS OF THE FORECAST  
AREA. AN ATMOSPHERIC KELVIN WAVE WILL MOVE THROUGH THE FORECAST  
AREA OVER THE NEXT FEW DAYS. THESE ARE EXPECTED TO ASSIST WITH  
SIGNIFICANT PRECIPITATION AMOUNTS IN SOME AREAS FOR THE NEXT  
SEVERAL DAYS.  
 
A SURFACE COLD FRONT IS PRESENT ACROSS THE CENTRAL ATLANTIC...THEN  
A STATIONARY FRONT IS LOCATED IN THE ATLANTIC AS WELL...FROM THE  
WESTERN TIP OF THE COLD FRONT...TO A SURFACE LOW CENTER NEAR 26N  
68W. THE DIVERGENT SIDE OF A MID LEVEL TROUGH WILL FAVOR THE  
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS THAT WILL AFFECT THE  
BAHAMAS...NORTHERN HISPANIOLA AND CUBA TODAY. SOME OF THE  
THUNDERSTORMS COULD BE STRONG AT TIMES...ESPECIALLY ACROSS  
HISPANIOLA. SHOWERS ARE STILL EXPECTED OVER THE REST OF THE  
GREATER AND LESSER ANTILLES AS THE MID LEVEL TROUGH MOVES EAST AND  
CAUSES DEVELOPMENT OF SHOWERS. IN ADDITION...THERE WILL BE AN  
UPPER LEVEL TROUGH MOVING THROUGH THE AREA THROUGH THE WEEKEND.  
DRIER THAN NORMAL AIR IS PRESENT OVER THE LESSER ANTILLES AND  
PUERTO RICO TODAY...BUT WILL GRADUALLY INCREASE AGAIN LATER  
TODAY...PEAKING EARLY SATURDAY MORNING...WHEN IT WILL BE ABOVE  
NORMAL. THE RELATIVELY DRY AIR WILL ALLOW SCATTERED SHOWERS...WITH  
RAINFALL TOTALS OF 05-10MM/DAY WITH MAXIMA UP TO 15MM. MOST OF THE  
DOMINICAN REPUBLIC AND NORTH HAITI ARE FORECAST TO RECEIVE THE  
LARGEST AMOUNTS OF 10-20MM/DAY WITH MAXIMAS OF 25-50MM. THE  
MAJORITY OF CENTRAL AND EASTERN CUBA AND JAMAICA ARE FORECAST TO  
OBSERVE 05-10MM/DAY WITH MAXIMAS OF 15-25MM. ON SATURDAY...PUERTO  
RICO...THE LESSER ANTILLES AND THE DOMINICAN REPUBLIC ARE EXPECTED  
TO RECEIVE BETWEEN 05-10MM/DAY WITH MAXIMA BETWEEN 15-25MM...BUT  
PUERTO RICO COULD OBSERVE VERY ISOLATED AMOUNTS UP TO 40MM.  
SOUTHERN CUBA AND NORTHERN BAHAMAS WILL OBSERVE 05-10MM WITH MAX  
OF 15MM. SUNDAY LOOKS LIKE A BETTER DAY OVERALL FOR THE BAHAMAS  
AND NORTHERN CARIBBEAN. ONLY A FEW SHOWERS WITH MINIMAL  
ACCUMULATIONS WOULD BE EXPECTED FOR CUBA AND MOST OF  
HISPANIOLA...BUT PUERTO RICO AND SOUTHERN DOMINICAN REPUBLIC COULD  
OBSERVE MORE PERSISTENT RAIN...THOUGH THE RAINFALL TOTALS WOULD BE  
GENERALLY BETWEEN 05-10MM WITH ISOLATED AMOUNTS UP TO 15-25MM. THE  
LESSER ANTILLES AND NORTHERN BAHAMAS ARE FORECAST TO OBSERVE  
00-05MM/DAY WITH MAX OF UP TO 10MM.  
 
OVER MEXICO AND CENTRAL AMERICA...PRECIPITATION IS FORECAST FOR  
NORTHERN NUEVO LEON AND TAMAULIPAS WITH 05-10MM/DAY WITH MAXIMAS  
OF 30-60MM WITH OCCASIONAL STRONG STORMS. CENTRAL AND SOUTHERN  
AREAS OF THE SIERRA MADRE ORIENTAL...SOUTHERN GUATEMALA AND EL  
SALVADOR...AND THE PACIFIC COASTS OF COSTA RICA AND WESTERN PANAMA  
ARE FORECAST 05-10MM/DAY WITH MAXIMAS OF 15-25MM. ON  
SATURDAY...OAXACA/GUERRERO ARE FORECAST TO OBSERVE 10-15MM/DAY  
WITH MAX OF 20-35MM. LESSER AMOUNTS OF RAIN ARE FORECAST FROM  
AROUND HIDALGO NORTH TO TAMAULIPAS...WITH RAINFALL AMOUNTS RANGING  
BETWEEN 00-10MM AND MAX UP TO 15MM. HOWEVER...THERE IS A SLIGHT  
CHANCE OF BRIEF STRONG STORMS OVER TAMAULIPAS. SOUTHERN GUATEMALA  
AND EL SALVADOR WILL OBSERVE UP TO 15MM AND COSTA RICA AND PANAMA  
IS EXPECTED TO OBSERVE 05-10MM/DAY WITH MAX UP TO 25MM. ON  
SUNDAY...THAT SAME AREA OF SOUTHERN MEXICO WILL ONCE AGAIN OBSERVE  
THUNDERSTORMS THAT COULD PRODUCE MAX AMOUNTS OF 20-35MM...WHILE  
AREAS FROM HIDALGO NORTH TO TAMAULIPAS AGAIN ARE EXPECTED TO  
OBSERVE 05-10MM WITH MAX UP TO 25MM.  
 
IN NORTHERN SOUTH AMERICA...DUE TO A KELVIN WAVE PASSING  
THROUGH...THERE WILL BE SIGNIFICANT SHOWERS EXPECTED THROUGH THE  
WEEKEND. TODAY...SOUTHERN VENEZUELA AND THE BRAZILIAN STATES OF  
RORAIMA AND AMAZONAS WILL SEE AMOUNTS OF 20-40MM/DAY WITH MAXIMA  
BETWEEN 50-100MM...WITH LOCALIZED AREAS THAT COULD SEE HIGHER  
AMOUNTS. FROM THE LAKE MARACAIBO REGION IN VENEZUELA TO EASTERN  
AND CENTRAL COLOMBIA...15-20MM/DAY IS FORECAST WITH MAXIMAS OF  
40-80MM...WESTERN COLOMBIA AND NORTH AND CENTRAL ECUADOR ARE  
FORECAST 15-20MM/DAY WITH MAXIMAS OF 30-60MM. THE GUIANAS AND  
NORTHEASTERN BRAZIL...AS WELL AS SOUTH-CENTRAL COLOMBIA INTO  
NORTHERN PERU ARE FORECAST AMOUNTS OF 10-15MM/DAY WITH MAXIMAS OF  
20-45MM. ELSEWHERE IN NORTHERN SOUTH AMERICA...RAINFALL AMOUNTS OF  
05-10MM/DAY WITH MAXIMAS OF 15-25MM COULD BE OBSERVED. SATURDAY  
HAS THE HIGHER AMOUNTS OF RAIN A BIT FURTHER EAST. AREAS OF  
NORTHERN VENEZUELA INTO THE GUIANAS ARE EXPECTED TO OBSERVE  
BETWEEN 15-20MM WITH MAX TOTALS OF 30-80MM. THE WESTERN SECTIONS  
OF THE PARA STATE IN BRAZIL IS FORECAST TO OBSERVE 20-40MM WITH  
MAXIMA BETWEEN 75-125MM. FROM ECUADOR TO WESTERN AND SOUTHERN  
COLOMBIA...THE RAIN WILL BE RELATIVELY MODEST...WITH 05-10MM/DAY  
AND MAX OF 15-25MM IN THE FORECAST. FOR SUNDAY...WESTERN  
VENEZUELA...COLOMBIA AND WESTERN ECUADOR IS FORECAST TO HAVE  
05-10MM WITH MAXIMA OF 15-25MM. FROM EASTERN ECUADOR...NORTHERN  
PERU...TO THE NORTHEAST ACROSS EASTERN COLOMBIA INTO THE SOUTHERN  
HALF OF VENEZUELA AND NORTHERN GUYANA...A LARGE AREA OF CONVECTION  
COULD CAUSE SOME AREAS TO OBSERVE 15-20MM WITH MAXIMA OF 35-70MM.  
THAT BEING SAID...THE LATEST MODEL GUIDANCE SUGGEST THAT AN AREA  
OF THE SOUTHERNMOST PART OF VENEZUELA AND ADJACENT AREAS IN BRAZIL  
COULD OBSERVE A LOCALIZED MINIMUM OF RAIN. FURTHER EAST ACROSS  
NORTHERN BRAZIL INTO THE SURINAME AND FRENCH GUIANA...ISOLATED  
THUNDERSTORMS COULD PRODUCE 10-15MM OF RAIN WITH MAXIMA OF  
20-35MM. A LOCALIZED MAXIMUM OF RAIN ACROSS THE EASTERN AMAZONAS  
STATE IN BRAZIL IS FORECAST TO OBSERVE 15-20MM WITH MAXIMA OF  
25-50MM.  
 
ALAMO/ACOSTA...WPC (USA)  
 

 
 
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