162
FXCA20 KWBC 051700
PMDCA
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1200 PM EST TUE DEC 05 2023
FORECAST BULLETIN 05 DEC 2023 AT 1700 UTC: A PERSISTENT MID-UPPER
TROUGH WEATHER PATTERN IS EXPECTED TO PERSIST ACROSS THE WESTERN
USA AND WEST MEXICO. EMBEDDED IN THIS PATTERN....SEVERAL SHORT
WAVE TROUGHS ARE FORECAST TO PROPAGATE EASTWARD...INTERACTING WITH
THE MID-UPPER RIDGE PRESENT ACROSS THE NORTHWEST CARIBBEAN AND
GREATER ANTILLES. THIS WILL FAVOR RECURRENT PERIODS OF ENHANCED
VENTILATION TO THE SOUTH OF THE SUBTROPICAL UPPER JET...WHICH WILL
FAVOR INTERMITTENT LIGHT RAIN SHOWERS ACROSS SOUTHWEST...CENTRAL
AND NORTHEAST MEXICO DURING THE NEXT SEVERAL DAYS. ON TUESDAY
EXPECT 05-10MM/DAY AND MAXIMA OF 15MM. THIS DECREASES ON WEDNESDAY
TO MAXIMA NEAR 10MM. ON THURSDAY...ANOTHER UPPER TROUGH ENTERS
FROM THE WEST TO FAVOR AN INCREASE TO 05-10MM/DAY AND MAXIMA OF
15MM FROM CENTRAL TO NORTHEAST MEXICO.
ANOTHER FEATURE OF INTEREST IS A SURFACE FRONT. GUIDANCE CONTINUES
RESOLVING THE BUILDING OF A STRONG POLAR RIDGE IN THE SOUTHERN
MISSISSIPPI VALLEY ON WEDNESDAY...WHICH IS FORECAST TO MEANDER TO
THE EAST SOUTHEAST AND CENTER JUST TO THE NORTH OF THE BAHAMAS IN
THURSDAY. THIS WILL ACCELERATE THE CURRENT FRONT SOUTHWARD. ON
TUESDAY EVENING...EXPECT THE FRONT ACROSS THE NORTHWEST
BAHAMAS...SOUTHEAST GULF OF MEXICO...22N 95W. BY WEDNESDAY EVENING
EXPECT THE FRONT ALONG THE CENTRAL BAHAMAS...CENTRAL CUBA...CAYMAN
ISLANDS...ISLAS DE LA BAHIA IN HONDURAS...CENTRAL GUATEMALA AND
THEN ALONG THE CONTINENTAL DIVIDE INTO CENTRAL MEXICO. BY THURSDAY
EVENING EXPECT THE FRONT ALONG 23N 60W...NORTHERN
HISPANIOLA...JUST NORTH OF JAMAICA...ISLAS DE LA BAHIA...CENTRAL
GUATEMALA. A SHEAR LINE IS ALSO ORGANIZING. BY TUESDAY EVENING
EXPECT IT ALONG THE CENTRAL BAHAMAS...CENTRAL CUBA...CAYMAN
ISLANDS...NORTHWEST HONDURAS. BY WEDNESDAY EXPECT IT ALONG
NORTHERN HISPANIOLA...EASTERN HAITIAN PENINSULA...NORTHEAST
NICARAGUA. BY THURSDAY EVENING EXPECT IT ALONG PUERTO RICO...16N
75W...NORTHEAST NICARAGUA.
INITIALLY/ON TUESDAY...EXPECT MAXIMA UNDER 10MM IN THE BAHAMAS
WITH THE FRONT AND IN THE CAYMAN ISLANDS WITH THE SHEAR LINE.
HIGHER AMOUNTS ARE EXPECTED IN PORTIONS OF SOUTHERN MEXICO AND
NORTHERN CENTRAL AMERICA DUE TO ENHANCED UPSLOPE ASSOCIATED WITH
NORTHEASTERLY LOW-LEVEL WINDS. THIS WILL FAVOR MAXIMA OF 15-30MM
FROM CENTRAL VERACRUZ/NORTHERN OAXACA INTO NORTHERN
HONDURAS/SOUTHERN BELIZE AND ISLAS DE LA BAHIA. ON WEDNESDAY...A
NORTES EVENT WILL HIGHLIGHT OROGRAPHIC ENHANCEMENT IN NORTHERN
OAXACA/SOUTHERN VERACRUZ WHERE EXPECT 20-40MM/DAY AND MAXIMA OF
75-125MM. FRONTAL CONVECTION IN CENTRAL GUATEMALA/NORTHWEST
HONDURAS/ISLAS DE LA BAHIA WILL FAVOR 15-20MM/DAYA ND MAXIMA OF
35-70MM. THE SHEAR LINE WILL FAVOR MAXIMA OF 20-35MM IN EAST
HONDURAS/NORTHEAST NICARAGUA. EXPECT LIGHTER AMOUNTS ELSEWHERE. ON
THURSDAY...FRONTAL CONVECTION WILL FAVOR MAXIMA OF 30-60MM IN
SOUTHERN BELIZE/CENTRAL GUATEMALA. IN HISPANIOLA AND JAMAICA THE
FRONT WILL FAVOR MAXIMA OF 20-35MM ESPECIALLY IN NORTHERN AND
EASTERN LOCATIONS. THE SHEAR LINE WILL FAVOR MAXIMA OF 20-35MM IN
NORTHEAST NICARAGUA/EAST HONDURAS. IN PUERTO RICO IT WILL
GENERALLY FAVOR MAXIMA OF 15MM.
THE PROMINENT MID-UPPER RIDGE IN THE NORTHERN CARIBBEAN IS AIDING
WITH THE AMPLIFICATION OF AN UPPER TROUGH ACROSS THE TROPICAL
ATLANTIC...JUST TO THE NORTH OF THE GUIANAS. THIS IS IN TERM
UNDULATING THE ATLANTIC ITCZ NORTHWARD AND INDUCING PERTURBATIONS
IN THE EASTERLY TRADES. GIVEN THAT THE UPPER TROUGH IS FORECAST TO
HOLD THROUGH THE CYCLE...IT WILL FACILITATE THE ARRIVAL OF A
TROPICAL MOIST PLUME FROM THE EQUATORIAL ATLANTIC INTO THE GUIANAS
AND WINDWARD ISLANDS. ON TUESDAY EXPECT 05-10MM/DAY AND MAXIMA OF
15-25MM IN THE NORTHERN GUIANAS...PEAKING IN COASTAL AREAS. ON
WEDNESDAY...EXPECT 05-10MM/DAY AND MAXIMA OF 15-30MM DEVELOPING
FROM TRINIDAD AND TOBAGO/NORTHEAST VENEZUELA INTO CENTRAL GUYANA.
IN SURINAME AND FRENCH GUIANA EXPECT MAXIMA OF 15-25MM. ON
THURSDAY...EXPECT 10-15MM/DAY AND MAXIMA OF 20-40MM FROM NORTHERN
GUYANA INTO GRENADA. IN THE CENTRAL LESSER ANTILLES EXPECT MAXIMA
OF 15MM. SIMILAR AMOUNTS ARE EXPECTED IN THE ABC ISLANDS AND
NORTHERN VENEZUELA AS THE MOIST PLUME MOVES IN.
DRIER CONDITIONS ARE EXPECTED IN NORTHWEST SOUTH AMERICA/SOUTHERN
CENTRAL AMERICA...WHERE RAINFALL WILL FOCUS IN REGIONS OF ENHANCED
ONSHORE WINDS//MOISTURE CONVERGENCE. THESE ARE SOUTHEAST
NICARAGUA...BOCAS DEL TORO IN PANAMA AND SOUTHWEST COLOMBIA...THE
LATTER DUE TO ITCZ CONVERGENCE. THE MOST SIGNIFICANT AMOUNTS ARE
EXPECTED IN SOUTHWEST COLOMBIA...WHERE MAXIMA WILL RANGE 20-60MM
ON A DAILY BASIS.
POSITIONS OF TROPICAL/EASTERLY WAVES INITIALIZED AT 12 UTC
NONE
GALVEZ...WPC (USA)
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