Prognostic Meteorological Discussion
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FXCA20 KWBC 051814
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
214 PM EDT THU MAY 05 2016

TROPICAL DISCUSSION FROM MAY 05/12UTC: CONSISTENT WITH PREVIOUS
FORECAST...A 500/250 HPA CLOSED HIGH TO THE SOUTH OF
COLIMA/NAYARIT IN SOUTHWEST MEXICO IS TO EXTEND A RIDGE ACROSS
MEXICO ALONG 100W/105W TO THE USA. THE RIDGE HOLDS THROUGH THE
MEDIUM RANGE PERIOD...AND IT IS TO FAVOR FAIR WEATHER CONDITIONS
ACROSS MOST OF MEXICO.

A HIGH AMPLITUDE TROUGH LIES TO THE EAST OF THIS RIDGE...WITH AXIS
SOUTH BETWEEN 100W-65W TO THE CARIBBEAN BASIN. UNDER INFLUENCE OF
THE LONG WAVE RIDGE TO THE WEST...THE TROUGH IS TO AMPLIFY ACROSS
THE CARIBBEAN TO SOUTHERN CENTRAL AMERICA LATER ON FRIDAY...WITH A
HIGHLY AMPLIFIED TROUGH TO THEN PERSIST INTO THE WEEKEND WHILE
SLOWLY MEANDERING EAST ACROSS THE NORTHERN CARIBBEAN ISLES. AT MID
LEVELS THE LONG WAVE TROUGH IS FOCUSING SHORT WAVE ENERGY ACROSS
THE BAHAMAS AND CUBA...WHILE AT 250 HPA A SUBTROPICAL JET MAXIMA
ROUNDING THE BASE OF THE TROUGH FAVORS AN UPPER DIVERGENT PATTERN.
AT LOW LEVELS THE TROUGH SUSTAINS A SURFACE FRONT THAT MOVES TO
THE CENTRAL/SOUTHEAST BAHAMAS TO CENTRAL CUBA TO NORTHERN
HONDURAS/ BELIZE LATER TODAY. DURING THE DAY ON FRIDAY THE FRONT
PUSHES FARTHER EAST ACROSS THE TURKS AND CAICOS-EASTERN CUBA WHILE
TRAILING ACROSS JAMAICA TO NORTHEAST NICARAGUA/HONDURAS. BOUNDARY
MEANDERS EAST TO THE WINDWARD PASSAGE/HAITI ON SATURDAY
MORNING...WHERE IT IS TO REMAIN WHILE GRADUALLY WEAKENING. FRONTAL
NORTHERLIES OF 15-20KT ARE EXPECTED OVER THE NEXT COUPLE OF DAYS
TO ENVELOP THE WESTERN CARIBBEAN AND THE GULF.

OVER VERACRUZ-CHIAPAS...THE POST FRONTAL NORTHERLIES WILL SUSTAIN
TOPOGRAPHICALLY INDUCED CONVECTION WITH RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-30MM THROUGH FRIDAY MORNING. THIS IS
TO ALSO FAVOR CONVECTION ACROSS NORTHERN HONDURAS TO SOUTHERN
BELIZE THROUGH FRIDAY WITH RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-45MM. OVER THE CENTRAL/SOUTHEAST BAHAMAS AND
CENTRAL/EASTERN CUBA...UNDER FAVORABLE JET DYNAMICS...THIS WILL
SUSTAIN RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 35-70MM
THROUGH FRIDAY. IT IS TO THEN FAVOR RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 25-50MM ON FRIDAY TO SATURDAY. THROUGH
FRIDAY MORNING CONVECTION SPREADS INTO JAMAICA WITH ACCUMULATION
OF 15-20MM/DAY AND MAXIMA OF 25-50MM...DECREASING TO 20-35MM ON
FRIDAY TO SATURDAY. ACROSS HAITI IT IS TO THEN TRIGGER RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM ON FRIDAY AND
SATURDAY. FURTHERMORE...THE BROAD POLAR TROUGH...AS IT EXTENDS
ACROSS THE BAHAMAS-CUBA...IT IS TO SUSTAIN AN INDUCED/INVERTED
TROUGH ACROSS THE CENTRAL CARIBBEAN. ALONG THIS AXIS...AN ILL
ORGANIZED LOW IS TO FORM NORTH OF LA GUAJIRA LATER ON FRIDAY. THIS
IS EXPECTED TO PERSIST THROUGH SATURDAY. AS THE TROUGH
DEVELOPS...IT IS TO FAVOR A MOIST NORTHEASTERLY FLOW INTO THE
CARIBBEAN PLAINS OF NICARAGUA...TO RESULT IN RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM/DAY THROUGH ON SATURDAY. THIS IS
TO ALSO ENHANCE MOISTURE CONVERGENCE ACROSS LA GUAJIRA PENINSULA
AND THE ABC ISLES...WITH RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15MM ON SATURDAY TO SUNDAY.

AS THE POLAR TROUGH DEEPENS TO THE WEST...A MID LEVEL SHORT WAVE
RIDGE WILL BUILD ACROSS THE EASTERN CARIBBEAN/VENEZUELA. THROUGH
FRIDAY EVENING/ SATURDAY MORNING A CAP INVERSION IS TO GRADUALLY
STRENGTHEN ACROSS PUERTO RICO-VIRGIN ISLES-ISLAND CHAIN.
THIS...IN-TURN...WILL RESULT IN GRADUAL DECREASE IN DIURNAL
CONVECTION...WITH MODELS TRENDING TOWARDS LESSER AMOUNTS DURING
THE WEEKEND. MEANWHILE...ACROSS PUERTO RICO EXPECTING RAINFALL
ACCUMULATION OF 00-05MM/DAY AND MAXIMA OF 10MM. IN A LONG FETCH
SOUTHERLY FLOW...THE MOST ACTIVE IS TO CLUSTER ALONG THE
CORDILLERA AND NORTH COAST OF THE ISLAND. OVER THE ISLAND CHAIN
THIS IS TO ONLY FAVOR LIGHT TO TRACE AMOUNTS OVER THE NEXT COUPLE
OF DAYS.

THE EASTERN PACIFIC ITCZ MEANDERS EAST ALONG 08N/09N INTO SOUTHERN
CENTRAL AMERICA...ENHANCING LOW LEVEL MOISTURE CONVERGENCE ACROSS
PANAMA-COSTA RICA. OVER COSTA RICA...IN INTERACTION WITH THE
CARIBBEAN TROUGH...EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-35MM. OVER PANAMA...THIS WILL RESULT IN RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM. ACROSS WESTERN
COLOMBIA TO NORTHWEST VENEZUELA DIURNAL CONVECTION IS TO CLUSTER
ON THE ANDES...TO RESULT IN RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-35MM. ALSO UNDER INFLUENCE OF THE CARIBBEAN
INDUCED/PREFRONTAL TROUGH... CONVECTION WILL INCREASE WHILE
SPREADING NORTH ACROSS LA GUAJIRA...WITH RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 25-50MM/DAY ON FRIDAY AND SATURDAY.
CONVECTION IS TO ALSO SPREAD ACROSS THE ABC ISLES EARLY ON SUNDAY
WITH ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15MM. OVER AMAZONIA
IN COLOMBIA TO AMAZONAS/RORAIMA HIGHLANDS IN VENEZUELA EXPECTING
DIURNAL CONVECTION TO FAVOR RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-35MM/DAY THROUGH SATURDAY. ACROSS THE GUIANAS TO
EASTERN VENEZUELA EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC.
INITIAL    24    36    48    60    72    84    96         TYPE
NONE

CARDOS...SMN (MEXICO)
CABANERIT...INAMEH (VENEZUELA)
DAVISON/GALVEZ...WPC (USA)
$$





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