483
FXCA20 KWBC 111904
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
204 PM EST MON DEC 11 2023
FORECAST BULLETIN 11 DEC 2023 AT 1800 UTC: A POLAR FRONT IS
SLOWING DOWN AS IT PROPAGATES SOUTHEASTWARD IN NORTHERN PORTIONS
OF THE DOMAIN. BY MONDAY EVENING THE FRONT IS EXPECTED ALONG THE
NORTHWEST BAHAMAS...CENTRAL CUBA...CENTRAL GUATEMALA...CHIVELA
PASS...JALISCO/AGUASCALIENTES IN CENTRAL MEXICO. ON TUESDAY...THE
BOUNDARY IS FORECAST TO BECOME STATIONARY ACROSS THE NROTHWEST
BAHAMAS...WHILE IT RETREATS NORTHWARD ACROSS WEST CUBA AND THE
YUCATAN CHANNEL. BY WEDNESDAY EVENING EXPECT THE BOUNDARY ACROSS
THE FAR NORTHWEST BAHAMAS...SOUTH FLORIDA...INTO THE RIO BRAVO
REGION. A SHEAR LINE WILL ALSO BE PRESENT ON MONDAY...AND BY THE
EVENING IT IS FORECAST ACROSS CENTRAL CUBA...THE CAYMAN ISLANDS
INTO NORTHEAST HONDURAS...TO THEN DISSIPATE. ANOTHER SHEAR LINE IS
FORECAST TO FORM ON WEDNESDAY...AND BY THE EVENING IT IS FORECAST
ACROSS THE NORTHWEST BAHAMAS...NORTHWEST CUBA...NORTHEAST YUCATAN
PENINSULA.
THE FRONT WILL FAVOR HEAVY RAINFALL IN NORTHERN HONDURAS/GULF OF
HONDURAS ON MONDAY AND TUESDAY...AS IT ENHANCES LOW-LEVEL MOISTURE
CONVERGENCE WHILE PRECIPITABLE WATER RANGES BETWEEN 55 AND 65MM.
ON MONDAY...EXPECT MAXIMA OF 75-125MM IN ISLAS DE LA BAHIA AND
NORTHWEST HONDURAS...WHILE IN COASTAL BELIZE AND CENTRAL
GUATEMALA/CHIAPAS EXPECT MAXIMA OF 20-40MM. THE SHEAR LINE WILL
FAVOR MAXIMA OF 20-35MM IN NORTHEAST HONDURAS/NORTHEAST
NICARAGUA...AND MAXIMA OF 15MM IN THE CAYMAN ISLANDS. IN THE
NORTHWEST BAHAMAS EXPECT MAXIMA OF 15-20MM. ON TUESDAY...ALTHOUGH
THE FRONT RETREATS NORTHWARD IN THE GULF OF HONDURAS...RETURNING
EASTERLY FLOW IS FORECAST TO TRANSPORT HEAVY RAIN PRODUCING
CONVECTION INTO BELIZE. BETWEEN ISLAS DE LA BAHIA...NORTHWEST
HONDURAS AND BELIZE EXPECT 25-50MM/DAY AND MAXIMA OF 75-150MM.
FRONTAL CONVECTION WILL FAVOR MAXIMA OF 15-25MM IN THE YUCATAN
PENINSULA AND MAXIMA OF 15MM IN MOST OF NORTHERN CUBA AND THE
NORTHWEST BAHAMAS. ON WEDNESDAY...LOW-LEVEL NORTHEASTERLIES ARE
FORECAST TO ACCELERATE ALONG THE FRONT IN THE NORTHWEST BAHAMAS.
THIS WILL POSE A RISK FOR ECHO TRAINING. GIVEN POSITIVE
INTERACTIONS WITH AN APPROACHING SHORT WAVE UPPER TROUGH...EXPECT
ACCUMULATION TO INCREASE TO 15-20MM/DAY AND MAXIMA OF 35-70MM IN
THE NORTHWEST BAHAMAS. THE FRONT WILL ALSO STIMULATE PRECIPITATION
IN NORTHEAST MEXICO. EXPECT 10-15MM/DAY AND MAXIMA OF 20-35MM IN
NORTHEAST COAHUILA...WHILE IN NIEVO LEON AND TAMAULIPAS EXPECT
MAXIMA OF 15MM. THE SHEAR LINE WILL FAVOR MAXIMA OF 20-35MM IN
NORTHWEST CUBA...WHILE IN EASTERN PORTIONS OF THE YUCATAN
PENINSULA EXPECT 15-20MM/DAY AND MAXIMA OF 25-50MM.
AS A LOW-LEVEL RIDGE STRENGTHENS ACROSS THE NORTH
ATLANTIC...EXPECT A STRENGTHENING OF THE NORTHEASTERLY LOW-LEVEL
WINDS ACROSS MOST OF THE CARIBBEAN. THIS WILL HIGHLIGHT SHALLOW
CONVECTIVE INSTABILITY IN THE LOW TROPOSPHERE DUE TO A SHALLOW
COLD-ADVECTIVE REGIME...AND WILL ALSO FAVOR EXTRACTION OF MOISTURE
FROM THE OCEAN. ACCORDINGLY...EXPECT AN INCREASE IN THE COVERAGE
OF VERY LIGHT RAIN SHOWERS IN THE NROTHEAST CARIBBEAN. ON MONDAY
THESE WILL FAVOR MAXIMA OF 10MM IN THE DOMININCAN
REPUBLIC...PUERTO RICO AND THE CENTRAL LESSER ANTILLES. THIS
INCREASES TO MAXIMA OF 15MM IN THE DOMINICAN REPUBLIC AND PUERTO
RICO ON TUESDAY. ON WEDNESDAY EXPECT MAXIMA OF 15MM IN THE CENTRAL
LESSER ANTILLES...PUERTO RICO/VI AND MOST OF THE NORTHEAST COAST
OF THE DOMINICAN REPUBLIC AND SOUTHEAST CUBA. SIMILAR AMOUNTS ARE
EXPECTED IN JAMAICA.
THE ACCELERATION OF THE TRADES IN THE CARIBBEAN WILL HIGHLIGHT
MOISTURE CONVERGENCE IN THE CARIBBEAN BASIN OF SOUTHERN CENTRAL
AMERICA. ON MONDAY EXPECT MAXIMA OF 30-60MM DEVELOPING IN
SOUTHEAST NICARAGUA/NORTHERN COSTA RICA...WHILE IN NORTHWEST
PANAMA EXPECT MAXIMA OF 15-20MM. ON TUESDAY EXPECT MAXIMA OF
20-35MM IN BOTH REGIONS. ON WEDNESDAY...EXPECT MAXIMA OF 25-50MM
IN NORTHWEST PANAMA WHILE IN SOUTHEAST NICARAGUA/NORTHEAST COSTA
RICA EXPECT MAXIMA OF 20-35MM.
SEASONALLY QUIET CONDITIONS ARE RETURNING TO NORTHERN SOUTH
AMERICA...WHERE DEEP LAYER MOISTURE IS ONCE AGAIN CONSTRAINED TO
THE AMAZON BASIN AND TO THE PACIFIC BASIN OF COLOMBIA. AN UPPER
TROUGH DEVELOPING ACROSS CENTRAL AMERICA ON WEDNESDAY IS EXPECTED
TO ENHANCE VENTILATION IN WESTERN COLOMBIA. THIS WILL RESULT IN AN
INCREASE IN RAINFALL ACCUMULATION TO FAVOR 10-15MM/DAY AND MAXIMA
OF 20-45MM WHERE THE ITCZ INTERACTS WITH THE CONTINENT. OTHERWISE
EXPECT DIURNAL CONVECTION TO GENERALLY FAVOR MAXIMA IN THE
15-20MM/DAY RANGE IN WESTERN COLOMBIA AND NORTHWEST ECUADOR. DRIER
CONDITIONS ARE EXPECTED IN VENEZUELA AND THE GUIANAS GIVEN MUCH
LOWER AMOUNTS OF AVAILABLE MOISTURE AND LACK OF ENHANCED UPPER
DIVERGENCE IN THE UPPER TROPOSPHERE.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
NONE
GALVEZ...WPC (USA)
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