105
FXCA20 KWBC 041822
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
122 PM EST MON DEC 04 2023
FORECAST BULLETIN 04 DEC 2023 AT 1820 UTC: A BROAD TROUGH EXTENDS
ACROSS THE CENTRAL USA. THIS TROUGH CONNECTS WITH AN UPPER TROUGH
THAT EXTENDS ACROSS TEXAS INTO SOUTHERN BAJA CALIFORNIA. AS THE
TROUGH IN MEXICO PRESSES AGAINST A BROAD UPPER RIDGE THAT CENTERS
IN SOUTHEAST CUBA/JAMAICA...IT CONTINUES TO SUSTAIN A STRONG
SUBTROPICAL UPPER JET THAT EXTENDS FROM NAYARIT/JALISCO INTO SOUTH
TEXAS ON MONDAY. THIS IS FAVORING ASCENT IN PORTIONS OF CENTRAL
MEXICO...FAVORING SCATTERED SHOWERS. THE TROUGH IS FORECAST TO
LIFT INTO THE SOUTHERN PLAINS OF THE USA EARLY ON WEDNESDAY
MORNING...WHILE ANOTHER TROUGH ARRIVES FROM THE WEST DURING THE
DAY ON WEDNESDAY. THIS WILL MAINTAIN UNSEASONABLY WET CONDITIONS
IN PORTIONS OF SOUTHWEST...CENTRAL AND NORTHEAST MEXICO. ON MONDAY
AND TUESDAY EXPECT 05-10MM/DAY AND MAXIMA NEAR 15MM. ON WEDNESDAY
THIS DECREASES TO MAXIMA OF 10MM IN THE MEXICAN PLATEAU...WHILE
ALONG THE SIERRA MADRE ORIENTAL EXPECT 05-10MM/DAY AND MAXIMA OF
15-25MM.
ALSO NORTH IN THE DOMAIN AND AT LOW-LEVELS...A FRONT IS PRESENT.
BY MONDAY EVENING THE FRONT IS FORECAST ACROSS THE FAR NORTHWEST
BAHAMAS...SOUTH FLORIDA...JUST NORTH OF THE NORTHERN YUCATAN
PENINSULA. BY TUESDAY EVENING EXPECT THE FRONT ACROSS THE CENTRAL
BAHAMAS...FLORIDA STRAIT...CENTRAL GULF OF MEXICO. ON
WEDNESDAY...AS A POLAR HIGH BUILDS IN THE SOUTHERN
PLAINS/MISSISSIPPI VALLEY...EXPECT A WIDESPREAD INCREASE IN THE
NORTHERLY LOW-LEVEL WINDS. THIS WILL ACCELERATE THE FRONT
SOUTHWARD. BY WEDNESDAY EVENING EXPECT THE BOUNDARY ACROSS THE
CENTRAL BAHAMAS...CENTRAL CUBA...JUST NORTH OF THE CAYMAN
ISLANDS...CENTRAL BELIZE/NORTH GUATEMALA INTO THE CHIVELA PASS
REGION. A PREFRONTAL SHEAR LINE IS FORECAST TO DEVELOP ON TUESDAY
TO EXTEND ACROSS THE CENTRAL BAHAMAS...CENTRAL CUBA...CAYMAN
ISLANDS...NORTHWEST HONDURAS. BY WEDNESDAY EVENING EXPECT IT
ACROSS NORTH HISPANIOLA...HAITIAN PENINSULA...NORTHEAST NICARAGUA.
IN TERMS OF PRECIPITATION HIGHLIGHTED BY THE FRONT...EXPECT LITTLE
IMPACT IN THE BAHAMAS DUE TO LIMITED AMOUNTS OF AVAILABLE MOISTURE
AND THE PRESENCE OF A ROBUST MID-LEVEL RIDGE EXTENDING AN AXIS
OVER THE GREATER ANTILLES AND BAHAMAS THROUGH THE ENTIRE FORECAST
CYCLE. HOWEVER...NORTHEASTERLY FLOW IN THE LOW-LEVELS WILL
INTERACT WITH TERRAIN IN SOUTHERN MEXICO AND NORTHERN CENTRAL
AMERICA TO FAVOR WETTER CONDITIONS. ON MONDAY...EXPECT 10-15MM/DAY
AND MAXIMA OF 20-35MM FROM SOUTHERN VERACRUZ INTO SOUTHERN
BELIZE/CENTRAL AND NORTHERN GUATEMALA. IN THE YUCATAN PENINSULA
AND IN THE REST OF VERACRUZ/NORTH OAXACA EXPECT MAXIMA OF 15MM. ON
TUESDAY...SHEAR LINE CONVECTION WILL FAVOR MAXIMA OF 10MM IN THE
CAYMAN ISLANDS...AND MAXIMA OF 15-30MM IN ISLAS DE LA BAHIA/SOUTH
BELIZE/CENTRAL GUATEMALA. PREFRONTAL ONSHORE FLOW WILL FAVOR
MAXIMA OF 15-30MM FROM CENTRAL VERACRUZ EAST INTO CAMPECHE. ON
WEDNESDAY...THE DEVELOPMENT OF A NORTES EVENT WILL FAVOR
20-40MM/DAY AND MAXIMA OF 75-125MM IN SOUTHERN VERACRUZ AND
NORTHEAST OAXACA. FRONTAL CONVECTION WILL FAVOR MAXIMA OF 20-35MM
IN BELIZE/GUATEMALA AND TABASCO. IN NORTHWEST HONDURAS AND ISLAS
DE LA BAHIA EXPECT MAXIMA OF 30-60MM. SHEAR LINE CONVECTION WILL
FAVOR MAXIMA OF 20-35MM IN EAST HONDURAS/NORTHEAST NICARAGUA AND
MAXIMA OF 15-20MM IN WESTERN PORTIONS OF HISPANIOLA.
IN A LARGE SCALE MID-UPPER PATTERN...A RIDGE CENTERS OVER THE
NORTHWEST CARIBBEAN AND EXTENDS INTO CENTRAL AMERICA AND FAR
NORTHWEST COLOMBIA. TO THE EAST...A TROUGH EXTENDS FROM THE
TROPICAL NORTH ATLANTIC NEAR 20N 47W ACROSS TRINIDAD AND TOBAGO
INTO CENTRAL COLOMBIA. MOST OF THE CARIBBEAN AND NORTHERN SOUTH
AMERICA LIES UNDER THE CONVERGENT AND DRY TIER OF THIS TROUGH. THE
PACIFIC ITCZ HAS MIGRATED SOUTHWARD AND NOW ENTERS THE CONTINENT
IN SOUTHWEST COLOMBIA. THIS IS FAVORING GENERALLY FAIR WEATHER IN
MOST OF CENTRAL AMERICA AND NORTHWEST SOUTH AMERICA. THE UPPER
TROUGH IS FORECAST TO GRADUALLY FILL THROUGH WEDNESDAY. THIS WILL
ALLOW FOR AN INCREASE IN UPPER DIVERGENCE/VENTILATION IN COLOMBIA
AND ECUADOR DUE TO THE NORTH QUADRANT OF THE BOLIVIAN
HIGH/SUBTROPICAL UPPER RIDGE. THIS EVOLUTION WILL FAVOR A GRADUAL
INCREASE IN ACCUMULATION FROM SOUTH TO NORTH. ON TUESDAY THROUGH
EARLY WEDNESDAY...THE COMBINATION BETWEEN MOIST ONSHORE FLOW AND
INCREASING VENTILATION WILL FAVOR 15-20MM/DAY AND MAXIMA OF
25-50MM IN SOUTHWEST COLOMBIA AND NORTHWEST ECUADOR. ON WEDNESDAY
EXPECT 15-20MM/DAY AND MAXIMA OF 30-60MM IN SOUTHWEST
COLOMBIA...WHILE IN THE EJE CAFETERO EXPECT MAXIMA OF 15-30MM.
TO THE EAST...THE ATLANTIC ITCZ IS FORECAST TO RETURN FROM
NORTHERN BRAZIL ON MONDAY TO NORTHERN GUYANA BY WEDNESDAY AS IT IS
DRAWN NORTHWARD BY THE UPPER TROUGH LOCATED TO THE EAST OF THE
WINDWARD ISLANDS. THIS WILL FAVOR A GRADUAL INCREASE IN
ACCUMULATION TO MAXIMA OF 15-25MM IN THE COASTAL GUIANAS ON
TUESDAY...SHIFTING TO GUYANA/WINDWARD ISLANDS ON WEDNESDAY.
NOTE...HOWEVER...THAT UNDER MODERATE NORTHEASTERLY TRADES...THE
LARGEST AMOUNTS ARE FORECAST TO CLUSTER ALONG COASTAL LOCATIONS
AND AREAS OFFSHORE.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
NONE
GALVEZ...WPC (USA)
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