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Tropical Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1824Z Aug 15, 2014)
 
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TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
224 PM EDT FRI AUG 15 2014

DISCUSSION FROM AUGUST 15/00UTC: MID/UPPER LEVEL RIDGE OVER
NORTHERN MEXICO/SOUTHWEST USA IS TO MAINTAIN ITS FOOTHOLD OVER
WESTERN PORTIONS OF THE DOMAIN DURING THE NEXT FEW DAYS. A TUTT
BOUNDS THE EASTERN PERIPHERY OF THIS RIDGE...WHILE A TUTT LOW TO
THE SOUTH IS RETROGRESSING ACROSS THE CENTRAL STATES OF MEXICO.
THE TUTT LOW MOVES ACROSS COLIMA-NAYARIT EARLY IN THE
CYCLE...MOVING SOUTH OF THE BAJA PENINSULA LATER THIS EVENING.
SIMULTANEOUSLY...THE TUTT TO THE EAST IS FORECAST TO PERSIST AS IT
IS EXPECTED TO STRENGTHEN THROUGH SATURDAY EVENING. A CLOSED LOW
IS TO FORM ALONG THIS AXIS OFF THE SOUTH COAST OF TEXAS/EAST OF
TAMAULIPAS LATER ON SATURDAY. THIS IS TO SLOWLY MOVE INLAND ACROSS
NORTHEAST-CENTRAL MEXICO LATER IN THE CYCLE. BEST INFLOW OF SHORT
WAVE ENERGY/COOL AIR ALOFT IS EXPECTED ACROSS VERACRUZ TO THE
CENTRAL STATES OF MEXICO/SIERRA MADRE DEL SUR. ACROSS VERACRUZ
EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM.
THROUGH SATURDAY EVENING THIS IS FORECAST TO INCREASE TO
15-20MM/DAY AND MAXIMA OF 25-50MM AS THE UPPER TROUGH DEEPENS.
ACROSS CENTRAL MEXICO/SIERRA MADRE DEL SUR EXPECT RAINFALL AMOUNTS
OF 15-20MM/DAY AND MAXIMA OF 25-50MM. THROUGH SUNDAY EVENING
MAXIMA DECREASES TO 20-40MM. ALONG THE SIERRA MADRE
OCCIDENTAL...TO AFFECT WESTERN CHIHUAHUA/SONORA-SINALOA EXPECTING
RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM. OTHER
ACTIVITY TO THE SOUTH IS TO AFFECT OAXACA-CHIAPAS/TABASCO IN
SOUTHERN MEXICO TO PORTIONS OF GUATEMALA...WITH RAINFALL AMOUNTS
OF 15-20MM/DAY AND MAXIMA OF 25-50MM.

ANOTHER TUTT LOW TO THE EAST LIES TO THE NORTH-NORTHEAST OF THE
DOMINICAN REPUBLIC. THIS TUTT SPLITS THE SUBTROPICAL RIDGE IN TWO
CELLS...ONE OVER THE BAHAMAS-EASTERN GULF...AND A BIGGER CELL OVER
THE CENTRAL ATLANTIC. THE TUTT WILL BE INFLUENCED BY THE RIDGE TO
THE WEST AND THE ONE TO THE EAST. THE ONE TO THE EAST FORCES THE
LOW TO LIFT NORTH TOWARDS BERMUDA...WHILE THE ONE TO THE WEST
SHEARS SHORT WAVE ENERGY ACROSS HISPANIOLA/CUBA. THROUGH SATURDAY
EVENING AN ILL ORGANIZED SHEAR AXIS IS TO THEN DEVELOP ACROSS CUBA
WITH CLOSED LOW OVER ISLA DE LA JUVENTUD. AT MID LEVELS...MODELS
INITIALIZED A SIMILAR PATTERN...WITH RIDGE SPLITTING IN TWO CELLS.
BUT THROUGH SATURDAY EVENING THE ONE OVER THE CENTRAL ATLANTIC IS
TO BECOME THE DOMINANT CELL WHILE BUILDING WEST ACROSS THE BAHAMAS
TO THE GULF OF MEXICO. AS A RESULT...TUTT INFLUENCE IS TO
GENERALLY LIMIT TO CUBA...WHERE IN INTERACTION WITH SEA BREEZE
CONVERGENCE EXPECTING A GRADUAL INCREASE IN ACTIVITY DURING THE
WEEKEND. INITIALLY EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15MM. THIS INCREASES TO 15-20MM/DAY AND MAXIMA OF
25-50MM LATER ON SUNDAY. ACROSS PUERTO
RICO-HISPANIOLA...MEANWHILE...THIS WILL TEND TO STRENGTHEN THE
TRADE WINDS CAP LATER DURING THE WEEKEND. AT LOW LEVELS...
PERSISTENT RIDGE IS TO DOMINATE THE FLOW ACROSS THE CARIBBEAN
BASIN-GULF OF MEXICO TO CENTRAL AMERICA...WITH AXIS TO ANCHOR ON A
HIGH NORTH OF THE DOMINICAN REPUBLIC. THE PERSISTENT LOW LEVEL
RIDGE PATTERN WILL SUSTAIN STRONG EASTERLY WINDS ACROSS THE LESSER
ANTILLES-CARIBBEAN BASIN...WITH 850 HPA WINDS OVER THE WINDWARD
ISLANDS TO PEAK AT 20-25KT...WHILE STRONGER WINDS OF 35KT ARE TO
DOMINATE THE SOUTHERN CARIBBEAN TO CENTRAL AMERICA.

THE MID/UPPER LEVEL RIDGE NORTH OF THE GREATER ANTILLES IS ALSO TO
STEER A WANING TUTT ACROSS CENTRAL AMERICA. THIS MOVES ACROSS
NICARAGUA-HONDURAS/EL SALVADOR...AND ACROSS GUATEMALA LATER THIS
EVENING/EARLY ON SATURDAY...THEN DISSIPATES AS IT MOVES TO THE
EASTERN PACIFIC/SOUTHERN STATES OF MEXICO. CONVECTIVE ENHANCEMENT
WITH THIS FEATURE IS TO LIMIT TO EASTERN NICARAGUA/NORTHEAST
HONDURAS OVER THE NEXT 24-36 HRS...WITH RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-25MM. AS IT PULLS ACROSS HONDURAS-EL
SALVADOR TO GUATEMALA IT IS TO THEN FAVOR RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-30MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
54W      58W    63W    67W    71W    75W    78W    81W     TW
85W      88W    91W    94W    97W    99W   102W   105W     TW

A TROPICAL WAVE IS INITIALIZED ALONG 54W EARLY THIS MORNING.
CONVECTION WITH THIS WAVE IS BUILDING TO THE WEST OF THE TROUGH
AXIS...SUGGESTING THAT THE WAVE HAS BECOME NEGATIVELY TILTED WITH
HEIGHT. THESE CONDITIONS ARE FORECAST TO PERSIST AS THE WAVE MOVES
ACROSS THE LESSER ANTILLES INTO THE CARIBBEAN BASIN. ALTHOUGH
LIKELY TO TRIGGER MODERATE TO STRONG CONVECTION...THIS WILL BE OF
SHORT DURATION. STRONG GUSTY WINDS ARE TO THEN ESTABLISH FOLLOWING
WAVE PASSAGE. ACROSS SURINAME-GUYANA/NORTHEAST VENEZUELA EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM. OVER THE
LESSER ANTILLES IT IS TO TRIGGER RAINFALL AMOUNTS OF 10-15MM/DAY
AND MAXIMA OF 20-40MM...WITH THE MOST INTENSE TO CLUSTER ACROSS
THE FRENCH-SOUTHERN LEEWARD ISLANDS. ACROSS THE VIRGIN
ISLES-PUERTO RICO AND THE DOMINICAN REPUBLIC IT IS TO ALSO FAVOR
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM ON
SATURDAY-SUNDAY MORNING. SOUTH ACROSS VENEZUELA-NORTHERN
COLOMBIA...THIS WAVE IS TO INTERACT WITH THE NEAR EQUATORIAL
TROUGH TO TRIGGER RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
25-50MM...WHILE OVER AMAZONIA TO THE SOUTH EXPECTING ACCUMULATION
OF 10-15MM/DAY AND MAXIMA OF 20-40MM. AS IT MOVES ACROSS HAITI TO
JAMAICA EXPECTING ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF
20-40MM. HIGHER AMOUNTS ARE EXPECTED ACROSS EASTERN CUBA WITH
MAXIMA OF 25-50MM...WHILE OVER WESTERN COLOMBIA THE MAXIMA IS TO
PEAK AT 35-70MM LATER ON SUNDAY. ON SUNDAY-MONDAY CONVECTION IS TO
SPREAD ACROSS CUBA WITH ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF
25-50MM...WHILE OVER THE CAYMAN ISLES THE MAXIMA PEAKS AT 15-20MM.
OVER PANAMA TO COSTA RICA EXPECTING ACCUMULATION OF 10-15MM/DAY
AND MAXIMA OF 20-40MM.

A WEAK TROPICAL WAVE ALONG 85W MOVES ACROSS NICARAGUA TO HONDURAS
THROUGH THIS EVENING...TO SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY
AND MAXIMA OF 20-30MM. OVER EL SALVADOR-HONDURAS TO GUATEMALA IT
IS TO THEN SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-40MM. ACROSS SOUTHERN TO CENTRAL MEXICO THIS INCREASES TO
15-20MM/DAY AND MAXIMA OF 25-50MM ON SUNDAY TO MONDAY.

VALVERDE...IMN (COSTA RICA)
MEDINA...ONAMET (REPUBLICA DOMINICANA)
DAVISON...WPC(USA)