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FXCA20 KWBC 221755
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
155 PM EDT FRI SEP 22 2023
FORECAST BULLETIN 22 SEP 2023 AT 1800 UTC: IN MEXICO...A ROBUST
HIGH PRESSURE SYSTEM ALOFT EXTENDS FROM THE SOUTHERN UNITED STATES
INTO NORTHERN CENTRAL AMERICA. DRY AIR CONTINUES TO BE ADVECTED
INTO NORTHEAST MEXICO AND LARGE AMOUNTS OF PRECIPITATION ARE NOT
EXPECTED. AN EASTERLY WAVE IS PROPAGATING OVER THE SOUTH AND
WEST...WHICH WILL BE THE MAIN REASON OF PRECIPITATION. TO THE
EAST...MOISTURE CONVERGENCE DUE TO THE TRADE WINDS WILL FAVOR
PRECIPITATION FOR FRIDAY AND THE REST OF THE WEEKEND. ON
FRIDAY...ALONG THE SIERRA MADRE OCCIDENTAL...EXPECT MAXIMA OF
15MM...WHILE FROM JALISCO...ALONG THE SIERRA MADRE DEL SUR...AND
INTO THE YUCATAN PENINSULA...EXPECT MAXIMA OF 15-25MM. ON
SATURDAY...JALISCO IS FORECAST A MAXIMA OF 20-35MM...WHILE THE
AFOREMENTIONED AREAS ALONG THE WEST AND SOUTHEAST CAN EXPECT
MAXIMA BELOW 25MM. ON SUNDAY...DRIER CONDITIONS ARE EXPECTED
THROUGHOUT MAJORITY OF THE WEST AND CENTRAL PORTIONS OF THE
COUNTRY...WHERE EXPECT ISOLATED MAXIMA OF 15-20MM. THE EASTERN
YUCATAN PENINSULA CAN EXPECT MAXIMA OF 20-35MM.
IN THE CARIBBEAN...A SURFACE FRONTAL BOUNDARY REMAINS TO THE NORTH
OF THE BAHAMAS...AND A PREFRONTAL SHEAR LINE EXTENDS OVER THE
CENTRAL BAHAMAS AND INTO CENTRAL CUBA. A PERSISTENT DEEP UPPER
TROUGH EXTENDS FROM THE EASTERN UNITED STATES INTO THE WEST
CARIBBEAN SEA...WITH ITS BASE NEAR EXTREME NORTH COLOMBIA. A
SERIES OF SHORT WAVE TROUGHS ARE EXPECTED TO PROVIDE VENTILATION
FOR DEEP CONVECTION OVER THE BAHAMAS AND CUBA ON FRIDAY AND INTO
THE WEEKEND. THE PREFRONTAL SHEAR LINE IS EXPECTED TO BY
SUNDAY...AND THE UPPER TROUGH IS FORECAST TO RETROGRADE TO THE
WEST. TO THE SOUTH...A TRAIN OF TROPICAL WAVES IS EXPECTED TO
PROPAGATE OVER THE CARIBBEAN BASIN ON FRIDAY AND INTO THE
WEEKEND...BRINGING PRECIPITATION TO THE LESSER ANTILLES AND
PORTIONS OF THE GREATER ANTILLES. ON FRIDAY...CENTRAL CUBA CAN
EXPECT MAXIMA OF 20-45MM...WHILE NORTHERN BAHAMAS...AND WESTERN
HISPANIOLA CAN EXPECT MAXIMA OF 20-35MM. GENERALIZE MAXIMA OF
15-25MM ARE EXPECTED IN PORTIONS OF CUBA...SOUTH BAHAMAS...TURKS
AND CAICOS...EAST HISPANIOLA AND INTO PUERTO RICO/VI...AND THE
LESSER ANTILLES. ON SATURDAY...A SHORT WAVE TROUGH FAVOR DEEPER
CONVECTION OVER THE BAHAMAS AND NORTHERN PORTIONS OF CUBA. IN THE
NORTH-CENTRAL BAHAMAS...EXPECT MAXIMA OF 25-50MM WITH A RISK OF
SQUALLY WEATHER...WHILE NORTHWEST CUBA CAN EXPECT MAXIMA OF
30-60MM WITH A RISK OF SEVERE WEATHER. THE SOUTHERN BAHAMAS AND
TURKS AND CAICOS ARE FORECAST MAXIMA OF 20-35MM...WHILE WESTERN
HISPANIOLA CAN EXPECT MAXIMA OF 20-45MM. ELSEWHERE IN THE GREATER
ANTILLES EXPECT MAXIMA OF 15-25MM. THE LESSER ANTILLES ARE
FORECAST MAXIMA OF 20-35MM. ON SUNDAY...EASTERN CUBA CAN EXPECT
MAXIMA OF 20-45MM. THE SOUTHERN BAHAMAS...TURKS AND
CAICOS...JAMAICA...AND THE LESSER ANTILLES ARE FORECAST MAXIMA OF
20-35MM. ELSEWHERE OVER THE CARIBBEAN BASIN EXPECT MAXIMA OF
15-25MM.
IN CENTRAL AMERICA...MOISTURE CONVERGENCE DUE TO FAVORABLE ONSHORE
FLOW...AND THE RETROGRADING UPPER TROUGH INTO THE EASTERN PORTION
OF THE REGION BY SUNDAY WILL ASSIST WITH PRECIPITATION ON FRIDAY
AND INTO THE WEEKEND. ON FRIDAY...EXPECT MAXIMA OF 20-35MM IN
WESTERN GUATEMALA AND MAXIMA OF 15-25MM ELSEWHERE IN THE REGION.
ON SATURDAY...EXPECT MAXIMA OF 20-35MM IN SOUTHWEST GUATEMALA AND
ALONG THE PACIFIC COAST OF COSTA RICA...WHILE THE REST OF THE AREA
CAN EXPECT MAXIMA BELOW 25MM. ON SUNDAY...THE AFOREMENTIONED UPPER
TROUGH RETROGRADES FROM THE WEST CARIBBEAN SEA TO THE GULF OF
MEXICO...WITH ITS BASE INTO EL SALVADOR...HONDURAS...AND WEST
NICARAGUA. THIS WILL FAVOR MAXIMA OF 20-45MM IN SOUTHERN
GUATEMALA...EL SALVADOR AND EXTREME SOUTH HONDURAS...AND MAXIMA OF
20-35MM FROM BELIZE...NORTHEAST GUATEMALA...AND NORTH HONDURAS.
NICARAGUA CAN EXPECT MAXIMA OF 15-25MM. COSTA RICA AND PANAMA CAN
EXPECT MAXIMA OF 20-35MM.
IN NORTHERN SOUTH AMERICA...TROUGHS AND TROPICAL WAVES ARE
FORECAST TO PROPAGATE OVER THE REGION ON FRIDAY AND OVER THE
WEEKEND. UPPER DIVERGENCE OVER BRASIL AND SOUTHERN VENEZUELA AND
THE GUIANAS IS FORECAST TO ASSIST WITH DEEP CONVECTION IN THE
AREA. BY SUNDAY...DRIER CONDITIONS ARE EXPECTED OVER THE GUIANAS
WITH THE ADVECTION OF DRY AIR FROM THE EAST. ON FRIDAY...MAXIMA OF
30-60MM ARE EXPECTED OVER EAST VENEZUELA...EXTREME WEST
GUYANA...AND NORTHERN RORAIMA-BRASIL. ELSEWHERE IN
VENEZUELA...EAST COLOMBIA...EAST GUYANA...WEST SURINAME...EXPECT
MAXIMA OF 20-35MM. WEST COLOMBIA CAN EXPECT MAXIMA OF 20-45MM.
ISOLATED MAXIMA UNDER 25MM ARE EXPECTED OVER THE REGION. ON
SATURDAY...MAXIMA OF 30-60MM IS EXPECTED IN CENTRAL AND WEST
COLOMBIA. MAXIMA OF 20-35MM IS FORECAST IN NORTHERN COLOMBIA AND
NORTHEAST VENEZUELA...AND MAXIMA OF 20-45MM IS EXPECTED FROM EAST
COLOMBIA THROUGH CENTRAL AND SOUTH VENEZUELA...AND INTO WEST
GUYANA. ON SUNDAY...INCREASE MOISTURE CONVERGENCE FROM ONSHORE
FLOW AND THE PASSING OF THE TROPICAL WAVE WILL FAVOR MAXIMA OF
40-80MM IN EXTREME SOUTHWEST COLOMBIA...AND MAXIMA OF 30-60MM IN
NORTHWEST COLOMBIA. EXTREME NORTHEAST COLOMBIA...THE LAKE
MARACAIBO REGION IN VENEZUELA...AND SOUTHERN VENEZUELA INTO
SOUTHEAST COLOMBIA...ARE FORECAST MAXIMA OF 20-45MMM.
ELSEWHERE...EXPECT ISOLATED MAXIMA OF 15-25MM.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
TYPE SOF INIT 23/00 23/12 24/00 24/12 25/00 25/12 26/00 26/12
TW 19N 45W 48W 51W 54W 57W 61W 65W 68W 72W
TW 20N 61W 64W 67W 70W 73W 76W 79W 81W 83W
TW 20N 69W 71W 73W 75W 77W ABSORBED
EW 19N 96W 99W 103W 107W 111W 115W EXIT
A TROPICAL WAVE IS INITIALIZED AT 45W AND TO THE SOUTH OF 19N. IT
IS EXPECTED TO REMAIN OVER THE OPEN WATERS OF THE ATLANTIC OCEAN
AND REACH THE EXTREME NORTH OF FRENCH GUIANA ON SATURDAY...WHERE
EXPECT MAXIMA OF 15MM. ON SUNDAY...THE WAVE WILL REACH THE LESSER
ANTILLES...WHERE EXPECT MAXIMA OF 20-35MM. NORTHEAST
VENEZUELA...AND NORTH GUYANA CAN EXPECT MAXIMA OF 15-20MM.
A TROPICAL WAVE IS INITIALIZED AT 61W AND TO THE SOUTH OF 20N. ON
FRIDAY...THE WAVE WILL FAVOR MAXIMA OF 30-60MM IN EASTERN
VENEZUELA...WEST GUYANA..AND NORTH RORAIMA-BRASIL. CENTRAL
VENEZUELA CAN EXPECT MAXIMA OF 20-35MM...AND SOUTHERN RORAIMA CAN
EXPECT MAXIMA OF 15-25MM. ON SATURDAY...FORECASTS ARE INDICATING
THE WAVE WILL SPEED UP AS IT PROPAGATES WEST. THE WAVE WILL FAVOR
MAXIMA OF 20-45MM IN SOUTH-CENTRAL VENEZUELA AND EAST COLOMBIA.
NORTHERN VENEZUELA...AND NORTHERN AMAZONAS-BRASIL CAN EXPECT
MAXIMA OF 15-25MM. BY SUNDAY...THE WAVE APPROACHES ANOTHER
TROPICAL WAVE MOVING SLOWER OVER PANAMA/COLOMBIA. THE WAVE WILL
FAVOR MAXIMA OF 40-80MM IN SOUTHWEST COLOMBIA...WITH ONSHORE FLOW
FAVORING MOISTURE CONVERGENCE IN THE AREA. MAXIMA OF 30-60MM ARE
EXPECTED IN THE CHOCO AND ANTIOQUIA REGIONS OF COLOMBIA...AND
MAXIMA OF 20-45MM ARE EXPECTED IN THE EXTREME NORTH OF COLOMBIA.
EASTERN PANAMA CAN EXPECT MAXIMA OF 20-35MM. ELSEWHERE IN COLOMBIA
EXPECT MAXIMA OF 15-25MM.
A TROPICAL WAVE IS INITIALIZED AT 69W AND TO THE SOUTH OF 20N. ON
FRIDAY... THE WAVE WILL FAVOR MAXIMA OF 20-35MM IN WESTERN
VENEZUELA AND EAST AND EAST COLOMBIA...AND WEST HISPANIOLA. MAXIMA
OF 15-25MM ARE EXPECTED IN NORTHEAST VENEZUELA...NORTH
COLOMBIA...AND EAST HISPANIOLA. ON SATURDAY...THE WAVES SLOWS DOWN
AND BEGINS TO LOSE DEFINITION IN RESPONSE TO A DEEP UPPER TROUGH
THAT EXTENDS INTO THE WEST CARIBBEAN SEA. IT WILL FAVOR MAXIMA OF
30-60MM IN CENTRAL AND WEST COLOMBIA...MAXIMA OF 20-35MM IN
NORTHERN COLOMBIA...AND MAXIMA OF 15-25MM IN SOUTHERN PORTIONS OF
COLOMBIA. THE WAVE IS EXPECTED TO LOSE DEFINITION AND BE ABSORBED
BY THE TROPICAL WAVE APPROACHING TO ITS EAST.
AN EASTERLY WAVE IS INITIALIZED AT 96W AND TO THE SOUTH OF 19N. ON
FRIDAY...THE WAVE WILL FAVOR MAXIMA OF 15-25MM FROM OAXACA TO
PORTIONS OF EASTERN MICHOACAN. ON SATURDAY...MAXIMA OF 20-35MM ARE
EXPECTED IN WEST JALISCO. BY SUNDAY... THE WAVE PROPAGATES OVER
THE OPEN WATERS OF THE PACIFIC OCEAN AND LITTLE TO NO EFFECTS ARE
EXPECTED OVER CONTINENT.
ACOSTA...WPC (USA)
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