Prognostic Meteorological Discussion
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FXCA20 KWBC 271838
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
238 PM EDT TUE JUN 27 2017

TROPICAL DISCUSSION FROM JUNE 27/12 UTC: AT 250 HPA...A CLOSED
HIGH OVER MICHOACAN/NAYARIT IN SOUTHWEST MEXICO ANCHORS A SHORT
WAVE RIDGE ACROSS MEXICO TO THE YUCATAN/NORTHERN CENTRAL AMERICA.
THE RIDGE ALOFT IS TO VENT DIURNAL CONVECTION ACROSS NORTHWEST
MEXICO...WITH ACTIVITY TO CLUSTER ALONG THE SIERRA MADRE
OCCIDENTAL OVER SONORA-SINALOA...WHERE WE EXPECT RAINFALL AMOUNTS
OF 05-10MM/DAY AND MAXIMA OF 15MM/DAY THROUGH FRIDAY. AS IT
MEANDERS OVER MEXICO...THE RIDGE ALOFT IS INDUCING THE SOUTHWARD
AMPLIFICATION OF A TROUGH ACROSS LOUISIANA-EASTERN MEXICO TO THE
WESTERN GULF. THE TROUGH REACHES MAXIMUM AMPLITUDE LATER
TODAY...TO THEN SLOWLY WEAKEN LATER ON THURSDAY AS SHORT WAVE
ENERGY SHEARS TO THE EAST-NORTHEAST ACROSS THE SOUTHERN USA. AS IT
DEEPENS THE TROUGH IS TO SUSTAIN ORGANIZED CONVECTION ACROSS
TAMAULIPAS TO COAHUILA IN NORTHEAST MEXICO...WITH ACCUMULATION OF
15-20MM/DAY AND MAXIMA OF 25-50MM. ON WEDNESDAY THIS DECREASES TO
10-15MM/DAY AND MAXIMA OF 20-35MM...WHILE ON THURSDAY THE MAXIMA
IS TO PEAK AT 20-45MM. ON THE CENTRAL STATES OF
MEXICO...MEANWHILE...THE RIDGE ALOFT IS TO VENT DEEP
CONVECTION...WITH RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-25MM. THROUGH THURSDAY THIS INCREASES TO 10-15MM/DAY AND MAXIMA
OF 20-45MM. OVER BELIZE-NORTHERN GUATEMALA AND THE YUCATAN
PENINSULA EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15MM...WHILE OVER SOUTHERN GUATEMALA-HONDURAS/EL SALVADOR
EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM.
LOCALLY HIGHER AMOUNTS ARE EXPECTED IN ASSOCIATION WITH TROPICAL
WAVES.

A TUTT TO THE EAST EXTENDS ACROSS THE BAHAMAS-CUBA TO THE WESTERN
CARIBBEAN. ALTHOUGH THIS IS TO PERSIST DURING THE NEXT FEW
DAYS...AS THE TUTT IS TO REMAIN CUT OFF FROM THE FLOW...IT IS
FORECAST TO GRADUALLY WEAKEN LATER IN THE WEEK. AT MID LEVELS...A
500 HPA CELL OF THE SUBTROPICAL RIDGE LIES OVER THE NORTHERN
CARIBBEAN/SOUTHWEST ATLANTIC. THIS IS TO PERSIST NEARLY UNCHANGED
DURING THE NEXT FEW DAYS. ACROSS CUBA AND HISPANIOLA THIS WILL BE
STRONG ENOUGH TO DELAY...BUT NOT STRONG ENOUGH TO SUPPRESS THE
ONSET OF DIURNAL CONVECTION. MEANWHILE...THE TUTT ALOFT IS TO
CONTINUE ENHANCING DIURNAL CONVECTION ACROSS CUBA WHERE WE EXPECT
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM. SIMILAR
AMOUNTS ARE EXPECTED ACROSS THE NORTHWEST BAHAMAS-CAYMAN ISLES AND
JAMAICA OVER THE NEXT DAY OR SO...DECREASING TO 05-10MM/DAY AND
MAXIMA OF 15MM ON WEDNESDAY-THURSDAY. ACROSS HISPANIOLA EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM. OVER PUERTO
RICO THE MOST ACTIVE CONVECTION IS TO CLUSTER ON WESTERN PORTIONS
OF THE ISLAND...WITH ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF
15MM.

A CELL OF THE SUBEQUATORIAL RIDGE LIES TO THE SOUTH...WITH AXIS AT
250 HPA EXTENDING EAST-TO-WEST ACROSS THE TROPICAL ATLANTIC-ISLAND
CHAIN TO THE CARIBBEAN/NORTHERN SOUTH AMERICA. THE RIDGE ALOFT IS
TO GENERALLY PERSIST DURING THE NEXT FEW DAYS. THIS IS TO CONTINUE
VENTING DEEP CONVECTION ACROSS EQUATORIAL SOUTH AMERICA. MOST
ACTIVE IS TO CLUSTER ALONG THE ITCZ/NEAR EQUATORIAL TROUGH OVER
THE GUIANAS-SOUTHERN/CENTRAL VENEZUELA TO COLOMBIA. ACROSS EASTERN
COLOMBIA-SOUTHERN VENEZUELA AND THE GUIANAS INITIALLY EXPECTING
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM. THROUGH
THURSDAY THIS INCREASES TO 20-30MM/DAY AND MAXIMA OF 35-70MM AS
ENHANCED BY STRONG TROPICAL WAVES PULLING ALONG THE NET/ITCZ.
ACROSS WESTERN COLOMBIA INITIALLY EXPECTING RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 25-50MM. THIS GRADUALLY DECREASES TO
05-10MM/DAY AND MAXIMA OF 15-25MM ON WEDNESDAY-THURSDAY.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC:
INITIAL   24     36     48     60     72     84     96       TYPE
32W      34W    37W    40W    43W    46W    49W     52W      TW
42W      45W    48W    51W    53W    56W    58W     61W      TW
54W      58W    61W    64W    67W    70W    73W     77W      TW
57W      60W    63W    67W    70W    73W    77W     81W  TUTT
INDUCED
71W      73W    76W    78W    81W    83W    85W     87W      EW
80W      83W    86W    89W    92W    94W    97W    100W      TW
87W      89W    92W    95W    97W    99W   101W    103W  TUTT
INDUCED

TROPICAL WAVE ALONG 32W REACHES EASTERN FRENCH GUIANA/AMAPA IN
BRASIL LATER ON FRIDAY...WHERE IT IS TO FAVOR RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM.

TROPICAL WAVE ALONG 42W REACHES EASTERN FRENCH GUIANA/AMAPA IN
BRASIL LATER ON WEDNESDAY/EARLY MORNING HOURS ON THURSDAY...WHERE
IT IS TO SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-30MM. ACROSS SURINAME TO GUYANA THIS IS TO THEN FAVOR RAINFALL
AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 35-70MM...TO AFFECT EASTERN
VENEZUELA ON FRIDAY-SATURDAY. ACROSS THE WINDWARD-FRENCH ISLES
EXPECTING ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15-25MM.

A PROGRESSIVE/NEGATIVELY TILTED TROPICAL WAVE IS INITIALIZED ALONG
54W...WITH ORGANIZED CONVECTION BUILDING TO THE WEST OF THE WAVE
AXIS. ACROSS SURINAME-GUYANA THIS IS TO SUSTAIN RAINFALL AMOUNTS
OF 10-15MM/DAY AND MAXIMA OF 20-45MM...WHILE OVER THE ORINOCO
DELTA/NORTHEAST VENEZUELA EXPECTING ACCUMULATION OF 05-10MM/DAY
AND MAXIMA OF 15MM...INCREASING TO MAXIMA OF 15-25MM ON WEDNESDAY.
OVER THE FRENCH/WINDWARD ISLES AND TRINIDAD THIS WILL ALSO TRIGGER
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-30MM. ON
WEDNESDAY FOCUS OF THE HEAVY CONVECTION SHIFTS TO THE
FRENCH-LEEWARD ISLANDS...WITH RAINFALL AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 30-60MM. ACROSS CENTRAL-EASTERN VENEZUELA ALSO EXPECTING
RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 30-60MM...INCREASING
TO 15-20M/DAY AND MAXIMA OF 35-70MM ON THURSDAY. OVER THE NORTHERN
LEEWARD-VIRGIN ISLES MOST INTENSE CONVECTION IS EXPECTED LATER ON
WEDNESDAY TO THURSDAY...WITH RAINFALL AMOUNTS OF 10-15MM/DAY AN
MAXIMA OF 20-30MM...WHILE ACROSS PUERTO RICO-THE DOMINICAN
REPUBLIC EXPECTING RAINFALL AMOUNT OF 10-15MM/DAY AND MAXIMA OF
20-40MM WITH MOST INTENSE ALONG THE CARIBBEAN COASTAL WATERS. ON
FRIDAY...AS IT PULLS ACROSS COLOMBIA IT IS TO SUSTAIN RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM.

TUTT LOW TO THE NORTH-NORTHEAST OF THE LEEWARD ISLES SUSTAINS AN
INDUCED INVERTED TROUGH IN THE MID LEVEL EASTERLY TRADES...WITH
AXIS ALONG 57W. THIS DECOUPLES FROM THE UPPER LEVEL CIRCULATION
EARLY IN THE CYCLE AND THEN PULLS TO THE EAST-SOUTHEAST ACROSS THE
NORTHEAST CARIBBEAN ISLES. CONVECTIVE ENHANCEMENT WITH THIS
FEATURE WILL LIMIT TO WESTERN PUERTO RICO AND THE DOMINICAN
REPUBLIC ON WEDNESDAY-THURSDAY...TO SUSTAIN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15MM.

AN EASTERLY WAVE TO THE SOUTH EXTENDS OVER SOUTH AMERICA ALONG
71W. ACROSS NORTHWEST VENEZUELA-ANDEAN REGION OF COLOMBIA THIS
WILL SUSTAIN RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
25-50MM. ACROSS PANAMA THIS IS TO THEN RESULT IN RAINFALL AMOUNTS
OF 05-10MM/DAY AND MAXIMA OF 15-25MM ON WEDNESDAY. AS IT MOVES
ACROSS WESTERN PANAMA-COSTA RICA-SOUTHERN NICARAGUA ON THURSDAY
THIS IS TO THEN TRIGGER RAINFALL AMOUNTS FO 10-15MM/DAY AND MAXIMA
OF 20-35MM...WITH SIMILAR AMOUNTS ACROSS HONDURAS ON FRIDAY.

A PROGRESSIVE TROPICAL WAVE EXTENDS ALONG 80W TO THE CAYMAN ISLES.
A TRADE WINDS SURGE AND DRY/DUSTY SAHARAN AIR LAYER TRAILS THIS
PERTURBATION. ACROSS JAMAICA-THE CAYMAN ISLES-CUBA THIS IS TO
TRIGGER RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM.
OVER PANAMA-COSTA RICA...IN INTERACTION WITH THE ITCZ...EXPECTING
RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 25-50MM. ACROSS
NICARAGUA/NORTHEAST HONDURAS THIS WILL INTERACT WITH THE WESTERN
CARIBBEAN TUTT TO SUSTAIN HIGHER RAINFALL AMOUNTS...WITH
ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF 35-70MM. AS IT SPREADS
ACROSS WESTERN HONDURAS/EL SALVADOR TO GUATEMALA THIS DECREASES TO
10-15MM/DAY AND MAXIMA OF 20-45MM ON WEDNESDAY...WITH SIMILAR
AMOUNTS ACROSS SOUTHERN AND CENTRAL MEXICO ON THURSDAY TO FRIDAY.

THE TUTT OVER THE WESTERN CARIBBEAN TRIGGERED A PERTURBATION IN
THE EASTERLY TRADES...WITH AXIS ALONG 87W. THIS DECOUPLES FROM
UPPER TROUGH EARLY IN THE CYCLE...AND AS IT PULL ACROSS
HONDURAS-BELIZE TO GUATEMALA/SOUTHERN MEXICO IT IS TO SUSTAIN
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM. OVER
CENTRAL MEXICO IT IS TO THEN INTERACT WITH MEANDERING UPPER LEVEL
TROUGH TO ALSO FAVOR RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-45MM.

GAJADHAR...SLMS (SAINT LUCIA)
GALVEZ/DAVISON...WPC (USA)
$$




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