916
FXCA20 KWBC 251955
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
254 PM EST MON NOV 25 2024
FORECAST BULLETIN 25 NOV 2024 AT 1900 UTC: UPPER CONVERGENT MJO
CONDITIONS CONTINUE AND ARE FORECAST TO PERSIST INTO NEXT WEEK.
THESE OFTEN ASSOCIATE WITH A DECREASE IN THE COVERAGE OF THE MOST
INTENSE PRECIPITATION.
A SYSTEM OF INTEREST IS A POTENT AND LARGE UPPER TROUGH THAT
EXTENDS FROM THE SOUTHEAST USA/FLORIDA INTO GUATEMALA. THIS TROUGH
IS A SLOW-TO-PROGRESS SYSTEM AND IS EXPECTED TO CONTINUE LOWERING
THE SURFACE PRESSURES IN THE WESTERN AND NORTH-CENTRAL CARIBBEAN.
ASSOCIATED WITH THIS EVOLUTION...WEAK PERTURBATIONS IN THE
EASTERLY TRADES CONTINUE PILING UP AND CONTRIBUTING TO AN INCREASE
IN PRECIPITABLE WATER. SATELLITE ESTIMATES INDICATE THAT A WIDE
REGION OF TOTAL PRECIPITABLE WATER OVER 55MM HAS BUILT IN AREAS
SOUTH OF JAMAICA AND HAITI. DEEP CONVECTION IS RESPONDING
ACCORDINGLY. MODELS AGREE ON THE GENERAL EVOLUTION BUT THERE ARE
IMPORTANT DISCREPANCIES ON THE DETAILS. TO START WITH...MODELS
HAVE BEEN STRUGGLING ON DEPICTING THE REGIONS WHERE THE STRONGEST
CONVECTION DEVELOPED DURING THE LAST TWO DAYS...WHICH HIGHLIGHTS
THE IMPORTANCE OF GAINING CONFIDENCE ON THE ANALYSIS OF THE FLOW
VERSUS RELYING ON MODEL RAINFALL. OUR ANALYSIS SUGGESTS THAT
THROUGH EARLY TUESDAY...THE HEAVIEST PRECIPITATION WILL CLUSTER IN
THE SOUTHEAST BAHAMAS AND THE TURKS AND CAICOS...WHERE THE
STRONGEST UPPER TROUGH DYNAMICS ARE EXPECTED. THIS WILL FAVOR
MAXIMA OF 50-100MM...WHILE IN THE CENTRAL BAHAMAS EXPECT MAXIMA OF
20-35MM. IN SOUTHEAST CUBA...JAMAICA AND THE WESTERN HAITIAN
PENINSULA EXPECT MAXIMA OF 25-50MM. ON TUESDAY...ACTIVITY IN THE
BAHAMAS IS EXPECTED TO PRODUCE MAXIMA OF 30-60MM IN THE SOUTHEAST
BAHAMAS AND TURKS AND CAICOS. TO THE SOUTH...EXPECT MAXIMA OF
35-70MM DEVELOPING IN THE HAITIAN PENINSULA AS WELL AS EASTERN
JAMAICA INCLUDING A RISK FOR MCS. IN SOUTHEAST CUBA AND THE REST
OF HAITI EXPECT MAXIMA OF 20-35MM...WHILE EXPECT SIMILAR AMOUNTS
IN WESTERN JAMAICA. ON WEDNESDAY...EXPECT THE HEAVIEST
PRECIPITATION AGAIN IN JAMAICA AND IN THE HAITIAN
PENINSULA...WHERE EXPECT MAXIMA OF 35-70MM. IN THE SOUTHEAST
BAHAMAS AND TURKS AND CAICOS EXPECT MAXIMA OF 20-45MM.
ANOTHER REGION OF INTEREST IN THE AREA IS SOUTHERN CENTRAL
AMERICA. THE AFOREMENTIONED EVOLUTION IN THE SOUTHERN CARIBBEAN IS
ATTEMTING TO DEVELOP A BAROCLINIC CENTRAL AMERICAN GYRE (CAG) IN
THE SOUTHWEST CARIBBEAN. ALTHOUGH MJO CONDITIONS ARE NOT
PARTICULARLY CONDUCIVE FOR THE DEVELOPMENT OF A CAG...ONSHORE
CONVERGENT FLOW AND ENHANCED VENTILATION IN SOUTHERN CENTRAL
AMERICA HAVE THE POTENTIAL OF INCREASING THE RISK OF HEAVY
PRECIPITATION ONCE AGAIN IN COSTA RICA AND PANAMA. THROUGH EARLY
TUESDAY...ONSHORE FLOW IN NORTHERN COSTA RICA WILL FAVOR MAXIMA OF
30-60MM WHILE ELSEWHERE IN COSTA RICA AND WEST PANAMA EXPECT
MAXIMA OF 20-35MM. ON TUESDAY EXPECT MAXIMA OF 30-60MM IN EASTERN
COSTA RICA...AND MAXIMA OF 20-40MM IN SOUTHERN COSTA RICA AND WEST
PANAMA. ON WEDNESDAY...EXPECT MAXIMA OF 50-100MM DEVELOPING IN
NORTHEAST COSTA RICA/SOUTHEAST NICARAGUUA AS WELL AS IN SOUTHEAST
PANAMA. IN SOUTHERN COSTA RICA AND WEST PANAMA EXPECT MAXIMA OF
25-50MM WHILE IN CENTRAL PANAMA EXPECT MAXIMA OF 20-40MM.
THE STRENGTHENING OF NORTHEASTERLY LOW-LEVEL WINDS ACROSS THE GULF
OF HONDURAS WILL STIMULATE MOISTURE CONVERGENCE ALONG THE NORTH
COAST OF HONDURAS ESPECIALLY ON TUESDAY. EXPECT MAXIMA OF 30-60MM
PEAKING ON TUESDAY AND EARLY HOURS OF WEDNESDAY...DECREASING
THEREAFTER.
EASTERLY/TROPICAL WAVES INITIALIZED AT 12 UTC
NONE
GALVEZ...(WPC)
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