532
FXCA20 KWBC 051934
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
233 PM EST FRI JAN 05 2024
FORECAST BULLETIN 05 JAN 2024 AT 1930 UTC: A POLAR MID-UPPER
TROUGH IS PROPAGATING ACROSS THE PLAINS OF THE USA ON FRIDAY. THIS
IS FAVORING CYCLOGENESIS IN THE SOUTHERN USA...AIDED BY UPPER JET
DYNAMICS. THIS PROCESS IS EXPECTED TO INTERACT WITH A SURFACE
FRONT. BY FRIDAY EVENING THE FRONT IS EXPECTED ACROSS SOUTHEAST
LOUISIANA INTO NORTHERN VERACRUZ. BY SATURDAY EVENING IT IS
EXPECTED ACROSS CENTRAL FLORIDA INTO 23N 94W. BY SUNDAY EVENING IT
IS EXPECTED ACROSS THE FAR NORTHWEST BAHAMAS...SOUTH FLORIDA INTO
THE CENTRAL GULF OF MEXICO. THE FRONT WILL START HIGHLIGHTING
PRECIPITATION ON SATURDAY. AS IT INTERACTS WITH THE BASE OF AN
UPPER TROUGH...IT WILL FAVOR THUNDERSTORMS IN THE NORTHWEST
BAHAMAS WITH FORECAST AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM. ON SUNDAY THIS DECREASES TO MAXIMA UNDER 10MM.
ANOTHER POLAR TROUGH IS EXPECTED TO ENTER THE ROCKIES AND
NORTHWEST MEXICO ON SUNDAY. THE AIR MASS WITH THIS SYSTEM WILL BE
SUFFICIENTLY COLD TO TRIGGER SNOWFALL ONCE AGAIN IN NORTHERN
CHIHUAHUA/SIERRA TARAHUMARA LATE ON SUNDAY INTO MONDAY MORNING.
EXPECT ACCUMULATION OF 05-10CM OF SNOW...ALTHOUGH ISOLATED HIGHER
AMOUNTS ARE POSSIBLE IN REGIONS OF OROGRAPHIC ENHANCEMENT.
ACROSS THE CARIBBEAN REGION...A HIGH PRESSURE WILL PROMOTE
EASTERLY WINDS OVER THE AREA...WHILE THERE WILL BE NEAR TO BELOW
NORMAL AVAILABLE MOISTURE. THE RAINFALL AMOUNTS OVER THE NEXT FEW
DAYS WILL BE MODEST...WITH AREAS ACROSS THE CARIBBEAN...CENTRAL
AMERICA AND NORTHERN SOUTH AMERICA OBSERVING EITHER NO RAIN OR
RAIN IN THE ORDER OF 01-10MM/DAY WITH ISOLATED MAX VALUES UP TO
25MM. A BROAD MID LEVEL HIGH IS DOMINATING THE CARIBBEAN REGION
AND IT IS PROMOTING STABILITY OVER THE AREA. THE EGDI ALGORITHM
DOES NOT SUGGEST A SIGNIFICANT RISK OF THUNDERSTORMS OVER THE AREA
THROUGH THE WEEKEND. THAT BEING SAID...PORTIONS OF NORTHERN SOUTH
AMERICA...GENERALLY OVER SOUTHERN VENEZUELA AND OVER
BRAZIL...SHOWERS AND THUNDERSTORMS ARE POSSIBLE DUE TO STRONGER
MID LEVEL WINDS AND NEAR NORMAL MOISTURE. THE EGDI ALGORITHM DOES
SUGGEST THUNDERSTORM POTENTIAL OVER SOME SECTORS OVER
BRAZIL...SOUTHERN VENEZUELA AND NORTHEASTERN PERU. THE RAINFALL
TOTALS COULD BE IN THE ORDER OF 15-30MM/DAY WITH ISOLATED MAXIMA
OF UP TO 50-80MM ACROSS DIFFERENT AREAS. THE MODEL GUIDANCE IS NOT
PARTICULARLY IN AGREEMENT...WITH THE GFS MODEL BEING IN GENERAL
MORE AGGRESSIVE WITH THE RAINFALL AMOUNTS...WHILE THE ECMWF IS
MORE GENERALIZED WITH THE COVERAGE. THEREFORE OUR FORECAST TAKES
UNCERTAINTY INTO CONSIDERATION AND SPLITS THE DIFFERENCE IN
RAINFALL AMOUNTS...AS WELL AS IT SHOWS MORE GENERALIZED RAINFALL
COVERAGE OF RAIN.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
NONE
GALVEZ/ALAMO...WPC (USA)
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