883
FXCA20 KWBC 221930
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
229 PM EST FRI NOV 22 2024
FORECAST BULLETIN 22 NOV 2024 AT 1930 UTC:
THE MID-UPPER FLOW IN THE NORTH HEMISPHERE WESTERLIES CONTINUES TO
BE LARGELY AMPLIFIED. EMBEDDED IN THIS AMPLE FLOW...A POTENT
TROUGH IN THE NORTH ATLANTIC IS SUSTAINING AN EXTENSIVE FRONT THAT
IS PROPAGATING SOUTHWARD ACROSS THE BAHAMAS...NORTHWEST CARIBBEAN
AND CENTRAL AMERICA. THE INTENSITY OF THIS SYSTEM AND LARGE VALUES
OF AVAILABLE MOISTURE IN THE CARIBBEAN WILL LIKELY FAVOR MODERATE
TO LOCALLY HEAVY RAINFALL IN PORTIONS OF COSTA RICA AND PANAMA
THROUGH THE FORECAST CYCLE.
IN TERMS OF FRONT POSITIONS...BY FRIDAY EVENING EXPECT THE FRONT
EXTENDING ACROSS THE TURKS AND CAICOS...FAR SOUTHEAST CUBA...JUST
TO THE WEST OF JAMAICA...CENTRAL NICARAGUA. BY SATURDAY EVENING
EXPECT THE FRONT JUST TO THE SOUTH OF THE TURKS AND
CAICOS...WINDWARD PASSAGE...JUST TO THE WEST OF JAMAICA...CENTRAL
NICARAGUA. BY SUNDAY EVENING EXPECT THE BOUNDARY TO START
RETREATING NORTHWARD WHILE THE TEMPERATURE GRADIENT LOSES
DEFINITION IN AREAS TO THE WEST OF THE CAYMAN ISLANDS. A SHEAR
LINE IS ALSO PRESENT. BY FRIDAY EVENING EXPECT IT FROM JUST
SOUTHWEST OF JAMAICA INTO CENTRAL COSTA RICA. BY SATURDAY
EVENING...EXPECT IS ACROSS THE CENTRAL DOMINICAN RPUBLIC...HAITIAN
PENINSULA...SOUTH OF JAMAICA...BOCAS DEL TORO IN PANAMA. BY SUNDAY
EVENING EXPECT IT ALONG 22N 60W INTO THE EASTERN DOMINICAN
REPUBLIC. IN TERMS OF RAINFALL AMOUNTS...ON FRIDAY EXPECT THE
HEAVIEST PRECIPITATION TO CLUSTER ACROSS EASTERN COSTA RICA AND
SOUTHEAST NICARAGUA WHERE SHEAR LINE CONVECTION WILL FAVOR MAXIMA
OF 50-100MM. MOIST NORTHERLY LOW-LEVEL FLOW WILL FAVOR MAXIMA OF
25-50MM IN MOST OF PANAMA. IN HONDURAS...POST FRONTAL NORTHERLIES
WILL CONTINUE TO INTERACT WITH TERRAIN TO FAVOR MAXIMA OF 20-35MM.
IN THE NORTH-CENTRAL CARIBBEAN...FRONTAL CONVECTION AND DIURNAL
HEATING WILL FAVOR 10-15MM/DAY AND MAXIMA OF 20-45MM IN SOUTHEAST
CUBA ON FRIDAY. IN THE SOUTHEAST BAHAMAS AND WEST HAITI EXPECT
MAXIMA OF 20-35MM. ON SATURDAY...EXPECT THE HEAVIEST PRECIPITATION
TO CONTINUE IN EASTERN COSTA RICA AND BOCAS DEL TORO...WHERE SHEAR
LINE CONVECTION WILL FAVOR MAXIMA OF 50-100MM. IN THE CENTRAL
CARIBBEAN...FRONTAL CONVECTION WILL FAVOR MAXIMA OF 20-35MM IN
SOUTHEAST CUBA...WHILE SHEAR LINE CONVECTION WILL FAVOR SIMILAR
AMOUNTS IN THE HAITIAN PENINSULA. IN THE DOMINICAN REPUBLIC THIS
WILL FAVOR MAXIMA OF 15MM. EXPECT SIMILAR AMOUNTS IN JAMAICA. ON
SUNDAY...EXPECT THE LARGEST AMOUNTS TO DEVELOP IN FAR SOUTHEAST
CUBA...AS AN EASTERLY LOW-LEVEL JET DEVELOPS ALONG THE FRONT AND
INCREASES THE POTENTIAL FOR ECHO TRAINING. GIVEN PRONOUNCED
OROGRAPHIC FORCING EXPECT MAXIMA OF 40-80MM. FRONTAL CONVECTION IS
EXPECTED ALSO IN THE TURKS AND CAICOS AND INAGUA...AS WELL AS THE
CAYMAN ISLANDS WHERE EXPECT MAXIMA OF 15-25MM. SHEAR LINE
CONVECTION WILL FAVOR MAXIMA OF 25-50MM IN THE EASTERN DOMINICAN
REPUBLIC...WHILE AREAS WEST IN HISPANIOLA SHOULD EXPECT MAXIMA OF
15-30MM.
ANOTHER EVOLUTION OF INTEREST IS THE POTENTIAL DEVELOPMENT OF
BROAD ROTATION IN THE WESTERN CARIBBEAN LATER IN THE WEEKEND INTO
EARLY NEXT WEEK. LARGE AND PERSISTENT UPPER TROUGH IN THE WESTERN
CARIBBEAN WILL FAVOR A GRADUAL DECREASE IN SURFACE PRESSURES IN
THE REGION. THIS WILL ALSO YIELD TO A GRADUAL INCREASE OF THE
EASTERLY TRADES ACROSS THE EASTERN CARIBBEAN...WHICH ARE
TRANSPORTING A MOISTER AIRMASS WESTWARD. THE PILING UP OF THESE
PERTURBATIONS AND DYNAMICS FROM THE UPPER TROUGH WILL GRADUALLY
SET UP AN ENVIRONMENT FAVORABLE FOR HEAVY RAINFALL FROM SUNDAY
THROUGH WEDNESDAY OR POTENTIALLY THURSDAY. THE DETAILS BEHIND THIS
EVOLUTION ARE STILL UNCLEAR. HOWEVER...VALUES OF PRECIPITABLE
WATER ARE EXPECTED TO INCREASE NOTABLY ALREADY BY SUNDAY.
FURTHERMORE...MODELS ARE ALREADY RESOLVING A PRONOUNCED TROUGH
EXTENDING FROM EAST PANAMA INTO JAMAICA. ENHANCED MOISTURE
CONVERGENCE IN EASTERN JAMAICA WILL LIKELY FAVOR MAXIMA OF 35-70MM
ON SUNDAY THROUGH EARLY MONDAY. ONSHORE FLOW IN EAST COSTA RICA
AND WEST PANAMA WILL FAVOR MAXIMA OF 30-60MM. NOTE THAT HIGHER
ACCUMULATIONS ARE EXPECTED NEXT WEEK.
IN NORTHERN SOUTH AMERICA...EXPECT MOST ACTIVITY TO CLUSTER IN
COLOMBIA GIVEN PERSISTENT VENTILATION AS THE REGION IS FORECAST TO
CONTINUE TO LIE UNDER THE DIVERGENT NORTHERN PERIPHERY OF THE
BOLIVIAN HIGH/SUBTROPICAL UPPER RIDGE OF SOUTH AMERICA.
PRECIPITABLE WATER IS EXPECTED TO REMAIN HIGH THROUGH THE FORECAST
CYCLE...FAVORING SCATTERED DEEP DIURNAL CONVECTION ON A DAILY
BASIS. THE FORECAST WEATHER PATTERN WILL FAVOR GENERALLY
10-15MM/DAY AND MAXIMA OF 20-45MM ON A DAILY BASIS.
EASTERLY/TROPICAL WAVES INITIALIZED AT 12 UTC
NONE
GALVEZ...(WPC)
JACKMAN...(BMS BARBADOS)
MATHIAS...(CIAARA-MB BRAZIL)
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