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
 
(Latest Discussion - Issued 1855Z Jun 11, 2021)
 
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
255 PM EDT FRI JUN 11 2021

TROPICAL DISCUSSION FROM JUN 11/19 UTC: MID/UPPER LEVEL LOW OFF
THE COAST OF TAMAULIPAS IN NORTHEAST MEXICO EXTENDS A TROUGH TO
THE SOUTHWEST ACROSS CENTRAL MEXICO TO AN ILL ORGANIZED LOW OFF
THE SOUTHWEST COAST NEAR COLIMA-NAYARIT. THE UPPER LEVEL FEATURE
IS INTERACTING WITH A BROAD LOW LEVEL TROUGH OVER THE EASTERN
PACIFIC/AREA OF DISTURBED WEATHER ALONG THE ITCZ MEANDERING SOUTH
OF GUERRERO/OAXACA. THIS IS ENHANCING CONVECTIVE DEVELOPMENT WHILE
DRAWING DEEP ITCZ MOISTURE NORTHWARD INTO MEXICO. THE MOIST
INFLOW...IN COMBINATION WITH STRONG TOPOGRAPHICAL FORCING...WILL
LEAD TO TWO ADDITIONAL DAYS OF TORRENTIAL RAINFALL AMOUNTS...WITH
RAINFALL AMOUNTS OF 20-40MM/DAY AND MAXIMA OF 75-150MM ACROSS
PORTIONS OF GUERRERO...OAXACA AND SOUTHERN CHIAPAS. THROUGH SUNDAY
THIS WEAKENS TO 15-20MM/DAY AND MAXIMA OF 35-70MM WHILE BUILDING
WEST ALONG THE SIERRA MADRE DEL SUR OVER COLIMA/NAYARIT TO
SOUTHERN SINALOA. HIGHER AMOUNTS...HOWEVER...ARE EXPECTED TO THE
NORTH ACROSS VERACRUZ...WITH ACCUMULATION OF 20-30MM/DAY AND
MAXIMA OF 50-100MM.

THE EVOLVING UPPER LEVEL PATTERN ACROSS WESTERN PORTIONS OF THE
DOMAIN IS TO ALSO ENHANCE CONVECTIVE DEVELOPMENT ACROSS NORTHERN
CENTRAL AMERICA. MOST ACTIVE IS TO CLUSTER BETWEEN EL
SALVADOR/SOUTHERN GUATEMALA EARLY IN THE CYCLE...WITH ACCUMULATION
OF15-20MM/DAY AND MAXIMA OF 35-70MM EARLY IN THE CYCLE. ON
SATURDAY THIS WEAKENS TO 05-10MM/DAY AND MAXIMA OF 15-25MM...WHILE
ON SUNDAY IT SURGES TO 10-15MM/DAY AND MAXIMA OF 20-40MM WHILE
BUILDING WEST ACROSS CHIAPAS IN SOUTHERN MEXICO. ACROSS
HONDURAS...MEANWHILE...EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY
AND MAXIMA OF 20-35MM. THROUGH THE WEEKEND THIS WEAKENS TO
05-10MM/DAY AND MAXIMA OF 15-25MM. ACROSS BELIZE/NORTHERN
GUATEMALA TO THE YUCATAN...DIURNAL CONVECTION WILL SUSTAIN
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM.

ALSO AT UPPER LEVELS...A SHORT WAVE RIDGE EXTENDS FROM CUBA/THE
BAHAMAS TO THE WESTERN ATLANTIC. SHORT WAVE TROUGH ON THE SOUTHERN
STREAM WILL PRESS AGAINST THIS AXIS...AND THROUGH MONDAY MORNING
THE RIDGE WILL RELOCATE WHILE THE TROUGH AMPLIFIES ACROSS THE
BAHAMAS-CUBA. THE COLD CORE UPPER LEVEL FEATURE IS TO THEN ENHANCE
CONVECTIVE INSTABILITY OVER THE ISLANDS...WITH CONVECTION ACROSS
CUBA/NORTHWEST BAHAMAS EXPECTED TO INTENSIFY/BECOME MORE
WIDESPREAD. DURING THE WEEKEND THIS WILL INCREASE TO 05-10MM/DAY
AND MAXIMA OF 15-25MM...WITH POTENTIAL FOR LOCALLY HIGHER RAINFALL
AMOUNTS. THIS IS TO ALSO FAVOR AN INCREASE IN CONVECTION ACROSS
THE CAYMAN ISLANDS DURING THE WEEKEND.

ANOTHER TROUGH TO THE EAST EXTENDS ALONG A WANING LOW NEAR 26N 62W
TO HISPANIOLA/NORTHWEST CARIBBEAN. THROUGH THE DAY A JET MAXIMA
ROUNDING THIS TROUGH IS TO DRAW THE UPPER LOW EASTWARD WHILE THE
BASE OF THE TROUGH BRIEFLY PULLS. BUT LATER DURING THE
WEEKEND...THE UPPER LEVEL TROUGH IS TO DEEPEN ONCE AGAIN TO THE
CENTRAL CARIBBEAN/NORTHER COLOMBIA. ALTHOUGH THE TROUGH DEEPENS
ACROSS THE BASIN...A MID LEVEL RIDGE BUILDING FROM THE EAST ACROSS
THE ISLANDS WOULD LIKELY NEGATE ANY FAVORABLE INFLUENCE THE UPPER
LEVEL TROUGH MIGHT HAVE ON WEATHER ACROSS THE EASTERN CARIBBEAN.
ENHANCEMENT...IF ANY...WILL LIMIT TO NORTHERN SOUTH AMERICA.
MEANWHILE...ACROSS PUERTO RICO AND HISPANIOLA CONVECTION IS TO
GRADUALLY WEAKEN DURING THE WEEKEND. OVER HISPANIOLA...EARLY IN
THE CYCLE EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-45MM. THROUGH SUNDAY IT DECREASES TO 05-10MM/DAY AND MAXIMA OF
15MM. ACROSS PUERTO RICO IT WILL DECREASE FROM 15-20MM/DAY AND
MAXIMA OF 30-60MM EARLY IN THE CYCLE TO 05-10MM/DAY AND MAXIMA OF
15MM ON SUNDAY.

TROPICAL WAVES/TUTT INDUCED PERTURBATIONS/TRADE WIND SURGES
INITIALIZED AT 12 UTC.
TYPE INIT  12/00 12/12 13/00 13/12 14/00 14/12 15/00  SOF
TW   43W   45W   48W   52W   55W   58W   61W   64W   16N
TW   69W   72W   75W   78W   81W   83W   85W   88W   13N
TW   81W   84W   87W   89W   92W   94W   96W   98W   15N
TW   92W   95W   98W  101W  104W  107W 109W  112W     14N

A TROPICAL WAVE ALONG 43W AND SOUTH OF 16N ENTERS FRENCH GUIANA
LATER ON SATURDAY EVENING...TO TRIGGER MODERATE CONVECTION WITH
ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF 20-35MM. THROUGH SUNDAY
THIS WILL SPREAD ACROSS SURINAME TO GUYANA/EASTERN VENEZUELA WHERE
IT IS TO RESULT IN SIMILAR RAINFALL AMOUNTS.

TROPICAL WAVE ALONG 69W AND SOUTH OF 13N...IN INTERACTION WITH THE
NEAR EQUATORIAL TROUGH OVER VENEZUELA...WILL SUSTAIN SCATTERED
DEEP CONVECTION ACROSS WESTERN VENEZUELA TO EASTERN
COLOMBIA...WITH ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF 20-35MM.
OVER THE ABC ISLAND/NORTHWEST COAST OF VENEZUELA EXPECTING
ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15MM. OVER NORTHWESTERN
COLOMBIA...THE WAVE INTERACTS WITH THE PANAMANIAN TROUGH TO
SUSTAIN RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 30-60MM. AS
IT SPREADS ACROSS THE DARIEN IN EASTERN PANAMA ON SATURDAY IT
DECREASES TO 10-15MM/DAY AND MAXIMA OF 20-45MM...WITH SIMILAR
AMOUNTS ACROSS COSTA RICA ON SUNDAY. OVER EASTERN
NICARAGUA/NORTHEAST HONDURAS THIS WILL THEN FAVOR RAINFALL AMOUNTS
OF 05-10MM/DAY AND MAXIMA OF 15-25MM.

TROPICAL WAVE ALONG 81W AND SOUTH OF 15N INTERACTS WITH THE
EASTERN PACIFIC ITCZ IN SUPPORT OF ORGANIZED DEEP CONVECTION
ACROSS COSTA RICA...WITH RAINFALL AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 35-70MM. ACROSS NICARAGUA TO HONDURAS EXPECTING RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM...WHILE OVER WESTERN 
HONDURAS/EL SALVADOR IT DECREASES TO 05-10MM/DAY AND MAXIMA OF
15-25MM ON SATURDAY. ACROSS GUATEMALA TO SOUTHERN MEXICO IT THEN
SURGES ON SUNDAY TO 10-15MM/DAY AND MAXIMA OF 20-40MM.

TROPICAL WAVE ALONG 92W AND SOUTH OF 14N IS INTERACTING WITH THE
EASTERN PACIFIC DISTURBANCE SOUTH OF MEXICO...TO ENHANCE
DEVELOPMENT ACROSS OAXACA AND GUERRERO TO RESULT IN RAINFALL
AMOUNTS OF 20-40MM/DAY AND MAXIMA OF 75-150MM. ACROSS
COLIMA-NAYARTI/SIERRA MADRE DEL SUR THIS DECREASES TO 10-15MM/DAY
AND MAXIMA OF 20-35MM ON SATURDAY. ON SUNDAY...ACTIVITY SURGES
ACROSS SONORA TO SUSTAIN RAINFALL AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 35-70MM.

DAVISON...WPC (USA)