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Tropical Discussion
 
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TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
207 PM EDT MON JUL 06 2020

TROPICAL DISCUSSION FROM JULY 06/16 UTC: NORTH IN THE DOMAIN AND
AT UPPER LEVELS...A WEAK AND DISORGANIZED RIDGE AXIS EXTENDS
ACROSS THE NORTHERN BAJA CALIFORNIA PENINSULA INTO NORTHWEST
MEXICO. TO THE EAST...A TUTT CENTERS OVER THE GULF OF MEXICO AND
EXTENDS A TROUGH AXIS INTO EASTERN MEXICO. THE TUTT IS FORECAST TO
MEANDER WESTWARD SLOWLY...TO ENHANCE CONVECTION PRIMARILY ALONG
ITS SOUTHERN AND WESTERN PERIPHERY. LARGEST AMOUNTS OF
PRECIPITABLE WATER AND INSTABILITY FOR DIURNAL CONVECTION ARE
PRESENT ACROSS SOUTHERN MEXICO AND THE GULF OF CALIFORNIA
REGION...WHERE CONVECTION WILL BE ACTIVE THROUGH THE CYCLE.
TROPICAL WAVES WILL ALSO PLAY A ROLE IN THE ORGANIZATION OF
CONVECTION. ON MONDAY...LARGEST ACCUMULATIONS ARE EXPECTED IN THE
EASTERN EJE VOLCANICO CENTRAL AND SIERRA MADRE DEL SUR...WHERE
TROPICAL WAVE WILL STIMULATE CONVECTION TO FAVOR 15-20MM/DAY AND
MAXIMA OF 25-50MM. IN SOUTHWEST MEXICO EXPECTING 10-15MM/DAY AND
MAXIMA OF 20-40MM. IN THE CENTRAL AND NORTHERN SIERRA MADRE
OCCIDENTAL EXPECTING 05-10MM/DAY AND MAXIMA OF 15-30MM. ON
TUESDAY...INTERACTION BETWEEN THE TROPICAL WAVE AND THE TUTT WILL
PEAK IN CENTRAL MEXICO AND THE SIERRA MADRE DEL SUR TO FAVOR
15-20MM/DAY AND MAXIMA OF 35-70MM. IN WESTERN MEXICO...FROM
KALISCO INTO THE SIERRA MADRE OCCIDENTAL OF SONORA AND CHIHUAHUA
EXPECTING 10-15MM/DAY AND MAXIMA OF 20-40MM. IN THE SIERRA MADRE
ORIENTAL...THE TUTT WILL DESTABILIZE THE TROPOSPHERE TO SUSTAIN AN
INCREASE IN THE COVERAGE OF DIURNAL CONVECTION WITH ACCUMULATIONS
OF 05-10MM/DAY AND MAXIMA OF 15-25MM. ON WEDNESDAY...LARGEST
ACCUMULATIONS ARE EXPECTED IN CENTRAL MEXICO AND ALONG THE SIERRA
MADRE OCCIDENTAL OF SINALOA AND SONORA...WHERE EXPECTING
15-20MM/DAY AND MAXIMA OF 25-50MM. IN SOUTHWEST MEXICO EXPECTING
05-10MM/DAY AND MAXIMA OF 15-25MM. A DRY AIR MASS ARRIVING FROM
THE CARIBBEAN WILL SUSTAIN MAXIMA UNDER 15MM/DAY IN AREAS TO THE
EAST OF 98W AND ISOLATED CONVECTION.

IN THE CARIBBEAN...A CELL OF THE SUBEQUATORIAL RIDGE CENTERS OVER
AND TO THE NORTHEAST OF THE LEEWARD ISLANDS. THE RIDGE IS FORECAST
TO MEANDER WESTWARD TO CENTER JUST TO THE SOUTH OF JAMAICA B
WEDNESDAY EVENING. THE RIDGE WILL PLAY A ROLE VENTILATING
CONVECTION...ESPECIALLY ALONG ITS SOUTHERN AND EASTERN PERIPHERY
PERIPHERY IN INTERACTION WITH TROPICAL WAVES. THIS WILL STIMULATE
RAINFALL ACCUMULATIONS IN THE WINDWARD ISLANDS ON MONDAY AND
LEEWARD ISLANDS ON TUESDAY. IN THE MID-LEVELS...A RIDGE CENTERS TO
THE SOUTHEAST OF BERNUDA BUT EXTENDS AN AXIS WESTWARD INTO THE
BAHAMAD ANS WESTERN CUBA. THE RIDGE IS FORECAST TO HOLD THROUGH
THE CYCLE...TO LIMIT THE COVERAGE OF CONVECTION IN THE BAHAMAS AND
CUBA THROUGH THE FORECAST CYCLE. WAVES IN THE TRADES WILL PLAY A
ROLE IN THE STIMULATION OF CONVECTION. ON MONDAY...LARGEST
ACCUMULATIONS ARE EXPECTED IN THE WINDWARD ISLANDS AND CENTRAL
LESSER ANTILLES...WHERE TROPICAL WAVE CONVECTION WILL FAVOR
05-10MM/DAY AND MAXIMA OF 15-30MM. SIMILAR AMOUNTS ARE EXPECTED IN
WESTERN PUERTO RICO. IN THE LEEWARD ISLANDS AND VIRGIN ISLANDS
EXPECTING MAXIMA OF 15MM. TO THE WEST...ISOLATED CONVECTION IN
HISPANIOLA AND THE NORTHWEST BAHAMAS WILL SUSTAIN 05-10MM/DAY AND
MAXIMA OF 15-25MM. IN CUBA EXPECTING ISOLATED AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. IN JAMAICA...EXPECTING MAXIMA
OF 15MM. ON TUESDAY...LARGEST ACCUMULATIONS ARE EXPECTED WITH THE
TROPICAL WAVE ACROSS THE LESSER ANTILLES INTO THE VIRGIN
ISLANDS...WHERE EXPECTING 10-15MM/DAY AND MAXIMA OF 20-35MM. IN
WESTERN PUERTO RICO AND IN HISPANIOLA EXPECTING 05-10MM/DAY AND
SCATTERED MAXIMA OF 15-25MM. N JAMAICA...GUBA AND THE NORTHWEST
BAHAMAS EXPECTING ISOLATED ACCUMULATIONS OF 05-10MM/DAY AND MAXIMA
OF 15-20MM. ON WEDNESDAY...TROPICAL WAVE CONVECTION IN HISPANIOLA
WILL SUSTAIN A PEAK IN ACCUMULATIONS...TO FAVOR 15-20MM/DAY AND
MAXIMA OF 25-50MM. CONVECTION IN JAMAICA AND SOUTHEAST CUBA ...AS
WELL AS WESTERN CUBA WILL SUSTAIN 05-10MM/DAY AND MAXIMA OF
15-25MM. SHOWERS IN THE SOUTHEAST BAHAMAS WILL SUSTAIN MAXIMA OF
10MM. DRY AIR MASS ARRICING FROM THE TROPICAL ATLANTIC WILL LEAD
TO A DECREASE IN THE COVERAGE OF CONVECTION AND ACCUMULATIONS IN
THE EASTERN CARIBBEAN. LARGEST AMOUNTS ARE EXPECTED IN THE
SOUTHERN WINDWARD ISLANDS AND IN PUERTO RICO...WHERE EXPECTING
MAXIMA UNDER 15MM/DAY.

CONVECTION IN NORTHERN SOUTH AMERICA AND CENTRAL AMERICA WILL BE
LARGELY SENSTIVE TO THE INFLUENCE OF TROPICAL WAVES AND THE
NET/ITCZ. SEE THE TROPICAL WAVE SECTION FOR MORE DETAILS ON
ACCUMULATIONS. DRY AIR MASS PROPAGATING ACROSS THE CARIBBEAN WILL
LIMIT ACCUMULATIONS IN NORTHERN CENTRAL AMERICA THROUGH THE
FORECAST CYCLE. IN SOUTH AMERICA...HOWEVER...ENHANCED LOW-LEVEL
MOISTURE CONVERGENCE AND VENTILATION IN THE SOUTHERN PERIPHERY OF
THE CELL OF THE SUBEQUATORIAL RIDGE LOCATED IN THE
CARIBBEAN...WILL FAVOR LARGER ACCUMULATIONS. ON MONDAY...LARGEST
AMOUNTS ARE EXPECTED IN CENTRAL.SOUTHERN VENEZUELA AND NORTHEAST
COLOMBIA WHERE EXPECTING 15-20MM/DAY AND MAXIMA OF 35-70MM. IN
WESTERN COLOMBIA INCLUDING THE VALLE DEL CAUCA EXPECTING
15-20MM/DAY AND MAXIMA OF 25-50MM. IN WESTERN PANAMA AND SOUTHERN
COSTA RICA EXPECTING MAXIMA OF 20-40MM. ON TUESDAY...LARGEST
ACCUMULATIONS ARE EXPECTED IN NORTHWEST COLOMBIA...WHERE ENHANCED
ONSHORE FLOW WILL INTERACT WITH THE ANDES TO FAVOR 15-20MM/DAY AND
MAXIMA OF 25-70MM IN THE EJE CAFETERO/ANTIOQUIA. IN SOUTHWEST
COLOMBIA EXPECTING 10-15MM/DAY AND MAXIMA OF 20-40MM. IN WESTERN
VENEZUELA AND NORTHERN COLOMBIA...TROPICAL WAVE CONVECTION WILL
FAVOR 10-15MM/DAY AND MAXIMA OF 20-40MM. ANOTHER TROPICAL WAVE
WILL FAVOR 10-15MM/DAY AND MAXIMA OF 20-35MM IN SOUTHEAST
VENEZUELA AND IN RORAIMA. ON WEDNESDAY..LARGEST AMOUNTS ARE
EXPETED IN NORTHERN...CENTRAL AND WESTERN COLOMBIA...WHERE
EXPECTING 15-20MM/DAY AND MAXIMA OF 25-50MM. IN THE DARIEN REGION
EXPECTING 05-10MM/DAY AND MAXIMA OF 15-30MM...AS WELL AS IN THE
AMAZON BASIN OF COLOMBIA.

IN THE GUIANAS...LARGEST AMOUNTS WILL INITIALLY CLUSTER TO THE
NORTH IN NORTHENR GUYANA...AS A TROPICAL WAVE ASSOCIATES WITH A
NORTHWARD MODULATION OF THE ITCZ. THIS WILL FAVOR 05-10MM/DAY AND
MAXIMA OF 15-30MM. AS THE ITCZ RETURNS SOUTHWARD...EXPECTING AN
INCREASE IN ACCUMULATIONS IN NORTHERN FRECH GUIANA...SURINAME AND
CENTRAL GUYANA BY WEDNESDAY...TO EXPECT SIMILAR ACCUMULATIONS.

TROPICAL/EASTERLY WAVES INITIALIZED ON JULY 06 AT 12 UTC:
TYPE - 06/12 07/00 07/12 08/00 08/12 09/00 09/12 10/00 SOF
TW   -   23W   27W   31W   35W   39W   43W   47W   51W 11N
TW   -   50W   55W   60W   64W   69W   73W   77W   81W 21N
TW   -   59W   63W   67W   71W   75W   79W   82W   86W 22N
TI   -   70W   75W   79W   82W   86W   91W   95W   99W 20N
TW   -   90W   93W   96W   99W  102W  DISS   ---   --- 16N
TW   -   98W  100W  102W  104W  106W  108W  110W  111W 15N
TW   -  114W  116W  118W  EXITS  ---   ---   ---   --- 21N

A TROPICAL WAVE IS INITIALIZED AT 23W. THE WAVE WILL REMAIN IN THE
TROPICAL ATLANTIC THROUGH THURSDAY EVENING...WHEN IT WILL APPROACH
FRENCH GUIANA.

A ROBUST TROPICAL WAVE IS INITIALIZED AT 50W. THE WAVE EXTENDS
NORTH INTO 20N...BUT DEEP CONVECTION IS OCCURRING TO THE SOUTH OF
15N. ON MONDAY...THE WAVE IS FORECAST TO ENHANCE CONVECTION IN
NORTHERN FRENCH GUIANA AND NORTHERN SURINAME WHERE IT WILL SUSTAIN
05-10MM/DAY AND MAXIMA OF 15MM. ON TUESDAY...THE WAVE WILL FAVOR
10-15MM/DAY AND MAXIMA OF 20-35MM IN THE CENTRAL AND NORTHERN
LESSER ANTILLES...INTO THE VIRGIN ISLANDS AND EASTERN PUERTO RICO.
IN NORTHERN SOUTH AMERICA...IT WILL FAVOR SIMILAR ACCUMULATIONS IN
SOUTHEAST AND SOUTHERN VENEZUELA/WESTERN GUYANA...WHILE IN
NORTHERN GUYANA AND NORTHEAST SURINAME IT WILL FAVOR 05-10MM/DAY
AND MAXIMA OF 15-20MM. ON WEDNESDAY...THE WAVE WILL STIMULATE
CONVECTION IN HISPANIOLA WHERE IT WILL SUSTAIN 15-20MM/DAY AND
MAXIMA OF 25-50MM. IN NORTHERN AND CENTRAL COLOMBIA IT WILL FAVOR
SIMILAR ACCUMULATIONS...WHILE IN THE COLOMBIA ORINOQUIA AND AMAZON
BASIN IT FAVORS 05-10MM/DAY AND MASIMA OF 15-30MM. NOTICE THAT
THIS WAVE IS BEING TRAILED BY A DRY AND STABLE AIR MASS ARRIVING
FROM THE TROPICAL ATLANTIC...AND WILL THUS BE FOLLOWED BY A SHARP
DECREASE IN RAINFALL ACCUMULATIONS.

A WEAK TROPICAL WAVE IS INITIALIZED AT 58/59W. THIS WAVE IS
ASSOCIATED WITH A NORTHWARD UNDULATION OF THE ITCZ...AND IS
ENHANCING CONVECTION TO THE EAST OF THE WINDWARD ISLANDS. ON
MONDAY...THE WAVE WILL FAVOR SCATTERED DEEP CONVECTION IN THE
WINDWARD ISLANDS NORTH INTO MARTINIQUE...TO SUSTAIN 05-10MM/DAY
AND MAXIMA OF 15-30MM. ACROSS THE LEEWARD AND VIRGIN ISLANDS THIS
WAVE WILL SUSTAIN 05-10MM/DAY AND MAXIMA OF 15MM. IN SOUTHWEST
PUERTO RICO...NORTHEASTERLY TRADES WILL INTERACT WITH THE
CORDILLERA TO FAVOR 05-10MM/DAY AND ISOLATED MAXIMA OF 15-30MM. IN
NORTHERN SOUTH AMERICA...INTERACTIONS WITH THE NET WILL FAVOR
15-20MM/DAY AND MAXIMA OF 25-50MM. ON TUESDAY...THE WAVE WILL
SUSTAIN 05-10MM/DAY AND MAXIMA OF 15-25MM IN HISPANIOLA AND
WESTERN PUERTO RICO. IN SOUTH AMERICA...LARGEST ACCUMULATIONS ARE
EXPECTED IN NORTHWEST VENEZUELA AND NORTHERN COLOMBIA IN
INTERACTION WITH THE NET...WHERE EXPECTING 10-15MM/DAY AND MAXIMA
OF 20-40MM. CONVERGENCE OF WESTERLY WINDS IN THE LOW LEVELS WILL
SUSTAIN MAXIMA OF 35-70MM IN NORTHWEST COLOMBIA/EJE CAFETERO. ON
WEDNESDAY...THE WAVE WILL ENHANCE CONVECTION IN JAMAICA AND
SOUTHEAST CUBA...WHERE IT WILL FAVOR 05-10MM/DAY AND MAXIMA OF
15-25MM. IN THE SOUTHEAST BAHAMAS EXPECTING MAXIMA OF 10MM. THE
WAVE WILL ENHANCE CONVECTION IN SOUTHERN CENTRAL AMERICA. IN
EASTERN PANAMA AND IN NORTHWEST COLOMBIA EXPECTING 05-10MM/DAY AND
MAXIMA OF 15-30MM. IN WESTERN PANAMA...COSTA RICA AND SOUTHEAST
NICARAGUA EXPECTING 10-15MM/DAY AND MAXIMA OF 20-40MM.

A PERTURBATION ORIGINALLY INDUCED BY A TUTT IS RAPIDLY PROPAGATING
ACROSS THE CENTRAL CARIBBEAN...AND IS INITIALIZED AT 70W AND TO
THE SOUTH OF 20N. THIS WAVE IS ENHANCING CONVECTION PRIMARILY IN
NORTHERN SOUTH AMERICA. ON MONDAY...IT WILL FAVOR 05-10MM/DAY AND
MAXIMA OF 15-25MM IN NORTHERN AND CENTRAL COLOMBIA. WHILE IN
WESTERN COLOMBIA IT WILL FAVOR 15-20MM/DAY AND MAXIMA OF 25-50MM.
IN HISPANIOLA...EXPECTING 05-10MM/DAY AND ISOLATED MAXIMA OF
15-25MM. ON TUESDAY...THE WAVE WILL ENHANCE CONVECTION PRIMARILY
IN CUBA...THE CAYMAN ISLANDS AND IN JAMAICA...WHERE EXPECTING
05-10MM/DAY AND MAXIMA OF 15-20MM. ON PANAMA AND COSTA RICA THE
WAVE WILL FAVOR MAXIMA OF 15MM. ON WEDNESDAY...THE WAVE WILL
ENHANCE CONVECTION IN NORTHERN CENTRAL AMERICA. BUT GIVEN THE
LIMITED AMOUNTS OF AVAILABLE MOISTURE THIS WILL SUSTAIN
05-10MM/DAY AND MAXIMA GENERALLY UNDER 15MM/DAY.

A TROPICAL WAVE IS INITIALIZED AT 90W AND HAS A STRONG SIGNATURE
IN CONVECTION OFF THE WEST COAST OF NORTHERN CENTRAL AMERICA. ON
MONDAY...THE WAVE WILL ENHANCE CONVECTION IN WESTERN GUATEMALA AND
CHIAPAS TO SUSTAIN 10-15MM/DAY AND MAXIMA OF 20-40MM. ON
TUESDAY...IT WILL ENLANCE CONVECTION IN OAXACA/GUERRERO AND
SOUTHERN PUEBLA TO SUSTAIN 15-20MM/DAY AND MAXIMA OF 35-70MM...AS
IT INTERACTS WITH A TUTT TO THE NORTH. ON WEDNESDAY...IT WILL
ENHANCE CONVECTION IN SOUTHWEST MEXICO AND THE CENTRAL EJE
VOLCANICO TO SUSTAIN 15-20MM/DAY AND MAXIMA OF 25-50MM STRETCHING
INTO THE SIERRA MADRE OCCIDENTAL OF SINALOA AND SOUTHERN SONORA.

A TROPICAL WAVE IS INITIALIZED AT 98W AND TO THE SOUTH OF 17W.
THIS WAVE IS FORECAST TO FORM A LOW AS IT PROGRESSES WESTWARD TO
THS SOUTH OF THE PACIFIC COAST OF MEXICO. ENHANCEMENT OF
CONVECTION WITH THIS WAVE WILL PRIMARILY REMAIN OFF THE COASTS OF
SOUTHERN MEXICO.

A TROPICAL WAVE IS INITIALIZED AT 114W AND TO THE SOUTH OF 21N.
THIS WAVE IS PROPAGATING AWAY OF THE FORECAST AREA INTO THE OPEN
WATERS OF THE TROPICAL CENTRAL PACIFIC.

GALVEZ/DAVISON...WPC (USA)