683
FXCA20 KWBC 101831
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
231 PM EDT WED MAY 10 2023
FORECAST BULLETIN FROM 10 MAY 2023 AT 1830 UTC: ZONAL WESTERLY
FLOW IN THE MID-UPPER TROPOSPHERE OVER MEXICO WILL LIMIT DIURNAL
THUNDERSTORM DEVELOPMENT TO SOUTHERN PORTIONS OF THE SOUTHERN
SIERRA MADRE ORIENTAL ON WEDNESDAY...AND TO CENTRAL AND SOUTHERN
PORTIONS ON THURSDAY...WHEN EXPECT 10-15MM/DAY AND ISOLATED MAXIMA
OF 20-35MM. AN UPPER TROUGH MOVES IN FROM THE SOUTHWEST USA ON
FRIDAY...TO HIGHLIGHT UPPER DIVERGENCE ACROSS NORTHEAST MEXICO.
GIVEN PRECIPITABLE WATER INCREASING TO 45-50MM ALONG THE RIO BRAVO
REGION BY FRIDAY...EXPECT THE DEVELOPMENT OF HEAVY RAINFALL.
EXPECT AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 40-80MM WITH A RISK
FOR SEVERITY.
A PERSISTENT UPPER TROUGH PATTERN OVER AND EAST OF THE EASTERN
SEABOARD...WILL CONTINUE TO FAVOR SURGES OF NORTHERLY LOW-LEVEL
FLOW AND STIMULATE THE FORMATION AND SOUTHWARD PROGRESSION OF
SURFACE FRONTS ACROSS THE BAHAMAS. A FRONT IS REORGANIZING ON
WEDNESDAY AND BY THE EVENING IT IS FORECAST ALONG 25-26N FROM 70W
INTO ELEUTHERA. BY THURSDAY EVENING IT IS FORECAST ACROSS THE
CENTRAL BAHAMAS INTO ANDROS ISLAND...WHILE A SHEAR LINE FORMS
ACROSS THE TURKS AND CAICOS...INAGUA INTO SOUTHEAST CUBA. BY
FRIDAY EVENING EXPECT THE FRONT CROSS EXUMA/ELEUTHERA INTO GRAND
BAHAMA...WHILE THE ILL-DEFINED SHEAR LINE EXTENDS INTO NORTHERN
HISPANIOLA AND THE HAITIAN PENINSULA. EXPECT LITTLE PRECIPITATION
ON WEDNESDAY EXCEPT IN HISPANIOLA...WHERE A PREFRONTAL TROUGH-LIKE
STRUCTURE WILL STIMULATE DIURNAL CONVECTION TO FAVOR 05-10MM/DAY
AND ISOLATED MAXIMA OF 15-30MM. ON THURSDAY...EXPECT 05-10MM/DAY
AND MAXIMA OF 15MM ACROSS THE CENTRAL AND SOUTHEAST
BAHAMAS...WHILE THE SHEAR LINE FAVORS 15-20MM/DAY AND MAXIMA OF
25-50MM IN SOUTHEAST CUBA. THE PREFRONTAL TROUGH WILL INTERACT
WITH A PASSING SHORT WAVE TROUGH IN HISPANIOLA TO FAVOR
15-20MM/DAY AND MAXIMA OF 25-50MM. ON FRIDAY...EXPECT AMOUNTS
INCREASING IN THE BAHAMAS TO 05-10MM/DAY AND MAXIMA OF 15-25MM IN
THURDERSTORMS. THE SHEAR LINE WILL FAVOR 10-15MM/DAY AND MAXIMA OF
20-45MM IN HISPANIOLA.
ALSO OF INTEREST IN THE NORTHWEST CARIBBEAN...A CLOSED UPPER LOW
IS FORECAST TO FORM OVER THE EASTERN GULF OF MEXICO ON
THURSDAY...TO DEEPEN AND MEANDER SOUTHEASTWARD THROUGH THE
WEEKEND. THIS WILL DESTABILIZE THE TROPOSPHERE OVER CUBA AND
ENHANCE VENTILATION...FAVORING THE DEVELOPMENT OF MODERATE
PRECIPITATION AND A RISK FOR SEVERITY ON THURSDAY AND FRIDAY.
WEDNESDAY...EXPECT DIURNAL CONVECTION TO FAVOR 05-10MM/DAY AND
MAXIMA OF 15-30MM IN MOST OF EASTERN AND CENTRAL CUBA. ON THURSDAY
EXPECT 10-15MM/DAY AND MAXIMA OF 20-35MM WITH A RISK FOR SEVERITY
IN WESTERN AND CENTRAL CUBA. ON FRIDAY...EXPECT SIMILAR
ACCUMULATIONS AND A RISK OF SEVERITY IN MOST OF CUBA.
AN INCREASING TREND IN PRECIPITATION IS EXPECTED IN CENTRAL
AMERICA AS A TRAIN OF EASTERLY/TROPICAL WAVES ENTERS THE REGION.
YET...LIMITED AVAILABLE MOISTURE AND UNFAVORABLE DYNAMICS FOR
ASCENT WILL LIMIT ACCUMULATIONS IN AREAS TO THE SOUTH OF
NICARAGUA...GENERALLY LIMITING MAXIMA OF 20-35MM IN PANAMA AND
15-25MM IN COSTA RICA DURING THE WETTEST DAYS. TO THE
NORTH...HOWEVER...ENHANCED INSTABILITY AND INTERACTION WITH SHORT
WAVE TROUGHS IN THE MID AND UPPER TROPOSPHERE WILL SET UP AN
ENVIRONMENT FAVORABLE FOR ISOLATED HIGHER AMOUNTS...REACHING
ISOLATED MAXIMA IN THE 25-60MM RANGE IN PORTIONS OF
GUATEMALA...HONDURAS...EL SALVADOR AND CHIAPAS IN THE AFTERNOONS
OF THURSDAY AND FRIDAY (SEE BELOW FOR DETAILS).
IN NORTHERN SOUTH AMERICA...CURRENT ACTIVE PATTERN IS FORECAST TO
YIELD TO A DECREASING TREND IN ACCUMULATIONS ACROSS
COLOMBIA...ECUADOR AND WESTERN VENEZUELA AS THE WAVES IN THE
TRADES EXIT THE REGION. HOWEVER...VENTILATION IS FORECAST TO
REMAIN ENHANCED ACROSS THE GUIANAS/NORTHERN BRASIL...WHICH WILL
FAVOR ROUNDS OF MODERATE PRECIPITATION ON A DAILY BASIS. THE
STRONGEST ACTIVITY WILL PRIMARILY CLUSTER ALONG THE NET AND BE
ENHANCED BY AN EASTERLY WAVE. INITIALLY...EXPECT ACTIVE CONVECTION
ALONG THE NET TO FAVOR 15-30MM/DAY AND ISOLATED MAXIMA OF 40-80MM
FROM RORAIMA...SOUTHERN VENEZUELA INTO CENTRAL COLOMBIA. IN
NORTHWEST AND NORTHERN COLOMBIA...EXPECT 15-20MM/DAY AND MAXIMA OF
25-50MM AIDED BY A TROPICAL WAVE. AFTER THIS PERIOD...EXPECT
15-20MM/DAY AND MAXIMA OF 25-60MM ON A DAILY BASIS IN THE GUIANAS
AND RORAIMA. IN COLOMBIA/ECUADOR/NORTHERN PERU...EXPECT A GRADUAL
DECREASING TREND...YIELDING TO 10-15MM/DAY AND ISOLATED MAXIMA OF
20-35MM BY FRIDAY.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
TYPE SOF INIT 11/00 11/12 12/00 12/12 13/00 13/12 14/00
EW 10N 53W 56W 58W 60W 62W 64W 66W 68W
TW 13N 73W 76W 78W 80W 82W 84W 87W 89W
EW 16N 83W 85W 87W 89W 91W 93W 95W 97W
AN EASTERLY WAVE IS INITIALISED AT 53W AND IS FORECAST TO
PROPAGATE FROM FRENGH GUIANA/SURINAME ON WEDNESDAY INTO CENTRAL
VENEZUELA BY SATURDAY MORNING. IT WILL GENERALLY FAVOR 15-20MM/DAY
AND MAXIMA OF 25-60MM IN THE GUIANAS...WHILE IN VENEZUELA IT WILL
FAVOR 10-15MM/DAY AND MAXIMA OF 20-35MM.
A TROPICAL WAVE IS INITIALIZED AT 73W AND IS PROPAGATING ACROSS
WESTERN COLOMBIA ON WEDNESDAY...TO FAVOR MAXIMA OF 25-50MM IN THE
EJE CAFETERO AND AREAS TO THE NORTH...AND MAXIMA OF 20-45MM IN
SOUTHWEST COLOMBIA/COASTAL ECUADOR. ON THURSDAY...IT WILL FAVOR
10-15MM/DAY AND MAXIMA OF 20-35MM IN PANAMA...AND MAXIMA OF 15MM
IN JAMAICA. ON FRIDAY...IT WILL FAVOR 05-10MM/DAY AND MAXIMA FO
15-25MM IN WESTERN PANAMA AND COSTA RICA...WHILE FROM NORTHEAST
COSTA RICA INTO NORTHEAST NICARAGUA EXPECT 10-15MM/DAY AND MAXIMA
OF 20-35MM.
AN EASTERLY WAVE IS INITIALIZED AT 83W AND IS PROPAGATING ACROSS
COSTA RICA...NICARAGUA AND HONDURAS ON WEDNESDAY. IT WILL FAVOR
ISOLATED CONVECTION IN COSTA RICA TO PRODUCE MAXIMA OF 15-25MM.
SIMILAR AMOUNTS ARE EXPECTED IN WESTERN HONDURAS/NORTHERN EL
SALVADOR WHILE IN NORTHERN NICARAGUA/EASTERN HONDURAS EXPECT
MAXIMA UNDER 15MM. ON THURSDAY...IT WILL FAVOR 15-20MM/DAY AND
ISOLATED MAXIMA OF 30-60MM FROM NORTHWEST NICARAGUA/SOUTHERN
HONDURAS/NORTHERN EL SAVADOR INCO CHIAPAS...AND MAXIMA OF 20-35MM
FROM CENTRAL HONDURAS INTO BELIZE/NORTHERN GUATEMALA. ON
FRIDAY...IT WILL FAVOR 15-20MM/DAY AND ISOLATED MAXIMA OF 25-50MM
FROM EL SALVADOR/SOUTHERN HONDURAS INTO WESTERN GUATEMALA. ACROSS
CENTRAL HONDURAS INTO CHIAPAS/TABASCO/NORTHERN GUATEMALA AND
BELIZE EXPECT 10-15MM/DAY AND MAXIMA OF 20-30MM.
GALVEZ/ACOSTA...WPC (USA)
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page