Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center
 
Tropical Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1731Z Apr 02, 2020)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
Abbreviations and acronyms used in this product


TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
131 PM EDT THU APR 02 2020

TROPICAL DISCUSSION FROM APRIL 2/18 UTC: NORTH IN THE FORECAST
AREA AND AT MIS-UPPER LEVELS...A SLOW TO PROGRESS PATTERN OF
RIDGES AND TROUGHS IS EXPECTED TO PERSIST THROUGH THE CYCLE. IN
THE MID-LEVELS...RIDGE PATTERN EXTENDS ACROSS CENTRAL MEXICO AND
THE WESTERN HALF OF THE GULF OF MEXICO AND THE YUCATAN
PENINSULA/GULF OF HONDURAS ON THURSDAY. TO THE EAST...A BROAD
TROUGH EXTENDS FROM THE FLORIDA PENINSULA EAST TO 65W AND SOUTH
INTO HISPANIOLA. THE PATTERN IS FORECAST TO EVOLVE SLOWLY...AS THE
RIDGE TENDS TO STRENGTHEN AND EXPAND INTO THE GULF OF HONDURAS BY
SATURDAY EVENING...WHILE THE BROAD TROUGH EXTENDS FROM THE BAHAMAS
EAST TO 55W...AND SOUTH TO 15N IN THE NORTHEAST CARIBBEAN. TRADE
WIND INVERSION ANALYSIS SHOWS THAT A WELL ESTABLISHED TRADE WIND
INVERSION WILL BE THE DOMINANT FEATURE IN THE REGION...TO SUSTAIN
LIMITED PRECIPITATION AMOUNTS THROUGH THE CYCLE.

EMBEDDED IN THIS FAIR WEATHER PATTERN...DISCRETE AREAS OF
CONVECTION AND PRECIPITATION ARE OCCURRING WITH A ROBUST SURFACE
FRONT MOVING SOUTHEASTWARD ACROSS THE BAHAMAS AND CUBA ON
THURSDAY. BY THURSDAY EVENING...IT WILL EXTEND ACROSS THE CENTRAL
BAHAMAS INTO EXTREME NORTHERN CUBA...WHILE A WEAKENING TAIL STALLS
ACROSS THE CENTRAL GULF OF MEXICO. BY FRIDAY EVENING THE FRONT
WILL ADVANCE TO EXTEND ACROSS NORTHERN HISPANIOLA...THE WINDWARD
PASSAGE...AND ALONG THE SOUTHERN COAST OF CUBA. BY SATURDAY
EVENING...THE FRONT WILL EXTEND ACROSS PUERTO RICO...CENTRAL
HISPANIOLA...ALONG THE NORTH COAST OF CUBA. ON THURSDAY...LARGEST
ACCUMULATIONS ARE EXPECTED IN SOUTHEAST CUBA TO REACH 05-10MM/DAY
AND MAXIMA OF 15-25MM. ACROSS THE SOUTHEAST BAHAMAS AND THE TURKS
AND CAICOS EXPECTING 05-10MM/DAY AND MAXIMA OF 15MM.
FRIDAY ACTIVITY WITH THE FRONT IS EXPECTED TO PEAK IN EXTREME
SOUTHEAST CUBA...IN NORTHERN HAITI AND IN THE NORTHERN AND CENTRAL
DOMINICAN REPUBLIC...WHERE IT WILL SUSTAIN SCATTERED AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-25MM. LIGHTER AMOUNTS ARE EXPECTED IN
SOUTHERN HAITI AND THE CAYMAN ISLANDS...WHERE PREFRONTAL
CONVECTION WILL SUSTAIN MAXIMA UNDER 10MM/DAY. THE FRONT WILL
ARRIVE INTO PUERTO RICO ON SATURDAY...ALTHOUGH MODELS ARE STILL
STRUGGLING ON AGREEING ON THE POSITIONING OF THE FRONT. UNDER THIS
EVOLUTION...EXPECTING A PEAK IN ACCUMULATIONS IN PUERTO RICO ON
SATURDAY-EARLY SUNDAY WITH EXPECTED AMOUNTS OF 05-10MM/DAY MAXIMA
OF 15-20MM. SIMILAR AMOUNTS ARE EXPECTED IN THE DOMINICAN REPUBLIC
UNDER THE INFLUENCE OF THE LINGERING FRONT. UNDER THE INFLUENCE OF
THE FORMING SHEAR LINE ON SATURDAY...EXPECTING SHALLOW CONVECTION
TO DEVELOP IN THE LEEWARD ISLANDS TO SUSTAIN 00-05MM/DAY AND
MAXIMA OF 10MM.

ANOTHER FRONT WILL APPROACH THE REGION FROM THE CENTRAL US ON
FRIDAY...TO EXTEND ALONG THE US-COAHUILA BORDER ON FRIDAY
AFTERNOON...WHERE IT WILL REMAIN THROUGH SATURDAY. MID-UPPER LEVEL
FLOW WILL BE FROM THE SOUTHWEST. MODELS AGREE ON A SHORT WAVE
TROUGH INTERACTING WITH A MOIST AND UNSTABLE PREFRONTAL AIRMASS ON
FRIDAY AFTERNOON. THIS POSES A MODERATE RISK FOR SEVERE
CONVECTIONS AND RAINFALL ACCUMULATIONS OF 05-10MMDAY AND MAXIMA OF
15MM IN EASTERN COAHUILA AND NORTHERN NUEVO LEON. LARGER AMOUNTS
ARE EXPECTED ON SATURDAY ALONG THE NORTHERN SIERRA MADRE
ORIENTAL...YET THE CONDITIONS WILL NOT BE PRONE FOR SEVERITY.
DURING SATURDAY-EARLY SUNDAY...EXPECTING ACCUMULATIONS OF
05-10MM/DAY AND MAXIMA OF 15-25MM.

OTHER AREAS OF PRECIPITATION WILL BE EASTERN PORTIONS OF THE EJE
VOLCANICO IN CENTRAL MEXICO...WHERE DIURNAL HEATING WILL PRODUCE
SUFFICIENT INSTABILITY TO OVERCOME THE STABILIZING OF THE
MOD-LEVEL RIDGE...FORECAST TO CENTER TO THE EAST OF THE REGION.
THIS WILL SUSTAIN ISOLATED SHOWERS AND THUNDERSTORMS TO PRODUCE
ACCUMULATIONS OF 00-05MM/DAY AND MAXIMA OF 10MM ON THURSDAY AND
FRIDAY...INCREASING TO 05-10MM/DAY AND MAXIMA OF 15M ON SATURDAY.
DIURNAL CONVECTION IS ALSO EXPECTED IN NORTHERN CENTRAL
AMERICA...ALONG THE MONTAINS OF EL SALVADOR...GUATEMALA AND
CHIAPAS. UNDER THE INFLUENCE OF STRENGTHENING MID=LEVEL RIDGE
PATTERN...THIS IS FORECAST TO GRADUALLY DECREASE FROM 05-10MM/DAY
AND MAXIMA OF 15MM IN CHIAPAS/WESTERN GUATEMALA ON THURSDAY...TO
05-10MM/DAY AND MAXIMA OF 15MM IN THE SAME REGION ON FRIDAY...TO
SIMILAR AMOUNTS SPREADING INTO EL SALVADOR ON SATURDAY. ALSO IN
CENTRAL AMERICA...ISOLATED CONVECTION WILL CONTINUE TO OCCUR ON A
DAILY BASIS OVER SOUTHERN COSTA RICA...TO PRODUCE AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-25MM ON THURSDAY...DECREASING TO
05-10MM/DAY AND MAXIMA OF 15MM THEREAFTER. ELSEWHERE IN THE
CARIBBEAN...EXPECTING VERY LIGHT ACCUMULATIONS.

IN NORTHERN SOUTH AMERICA...THE UPPER SUBEQUATORIAL RIDGE
CONTINUES BUILDING. THIS IS BEING AIDED AS WELL BY A TROPOSPHERIC
KELVIN WAVE THAT IS FORECAST TO CENTER OVER VENEZUELA AND THE
GUIANAS ON THURSDAY TO THEN EXIT INTO THE ATLANTIC. UNDER THE
INFLUENCE OF ENHANCED SOUTHERLY LOW-LEVEL FLOW ALONG THE COLOMBIAN
ORINOQUIA...THE FOCUS FOR MOISTURE CONVERGENCE ON THURSDAY WILL
EXTEND ACROSS THE NORTHERN COLOMBIAN ORINOQUIA INTO THE ORINOQUIA
OF WESTERN VENESUELA. IN THESE REGIONS EXPECTING AMOUNTS OG
15-20MM/DAY AND MAXIMA OF 25-50MM. LARGER AMOUNTS ARE EXPECTED IN
THE AMAXON BASIN...WHERE A ROBUST EASTERLY WAVE AHEAD OF A TRADE
WIND SURGE WILL SUSTAIN 15-30MM/DAY AND MAXIMA OF 40-80MM.
CONVECTION IN THE NORTHWEST HALF OF COLOMBIA WILL SUSTAIN
05-10MM/DAY AND MAXIMA OF 15-25MM...WHILE THE BAJO MAGDALENA
EXPECTS 10-15MM/DAY AND ISOLATED MAXIMA OF 20-40MM. BY
FRIDAY...THE FOCUS FOR STRONGEST CONVECTION WILL EXTEND FOM THE
COLOMBIAN AND VENEZUELAN AMAZON INTO WESTERN/NORTHEAST COLOMBIA
WHERE EXPECTING 15-20MM/DAY AND MAXIMA OF 25-50MM. IN NORTHWEST
COLOMBIA10-15MM/DAY AND MAXIMA OF 20-35MM.

IN THE GUIANAS...AS TRADE WIND SURGE/EASTERLY WAVE PHASES WITH THE
TROPOSPHERIC KELVIN WAVE CROSSING ON THURSDAY...IT WILL SUSTAIN
RAINFALL ACCUMULATIONS OF 15-30MM/DAY AND MAXIMA OF 40-80MM ON
THURSDAY...DECREASING TO 15-20MM/DAY AND MAXIMA OF 30-60MM BY
FRIDAY. THESE AMOUNTS WILL AFFECT THE SOUTHERN GUIANAS AND MOST OF
EASTERN FRENCH GUIANA. A DECREASE TO 10-15MM/DAY AND MAXIMA OF
20-40 IN THE SOUTHERN GUIANAS IS EXPECTED BY SATURDAY.

GALVEZ/DAVISON...WPC (USA)