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Tropical Discussion
 
(Latest Discussion - Issued 1830Z Jul 16, 2018)
 
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TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
230 PM EDT MON JUL 16 2018

TROPICAL DISCUSSION FROM JUL 16/12 UTC: AT 250 HPA...BROAD CELL OF
THE SUBTROPICAL RIDGE DOMINATES THE FLOW OVER THE SOUTHERN
USA/GULF OF MEXICO. A TUTT SOUTH OF THIS RIDGE EXTENDS ACROSS THE
CENTRAL TO NORTHERN STATES OF MEXICO. THE RIDGE TO THE NORTH IS TO
STEER THE TROUGH WEST ACROSS THE NORTHERN STATES OF MEXICO TO THE
GULF OF CORTEZ LATER ON TUESDAY/EARLY WEDNESDAY MORNING...TO THEN
MEANDER ACROSS THE BAJA PENINSULA LATER IN THE DAY. AS IT MEANDERS
WEST...THE TROUGH IS TO ENHANCE DIURNAL CONVECTION ACROSS
SONORA/NORTHERN SINALOA MEXICO...WITH RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 35-70MM. ON TUESDAY THIS DECREASES TO
15-20MM/DAY AND MAXIMA OF 25-50MM. ON WEDNESDAY-THURSDAY EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM. OTHER
CONVECTION IS EXPECTED ACROSS CHIHUAHUA EARLY IN THE CYCLE...TO
SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM.

ANOTHER TUTT TO THE SOUTH EXTENDS FROM THE NORTHEAST
CARIBBEAN/CUBA...ACROSS THE YUCATAN PENINSULA TO AN ILL ORGANIZED
LOW SOUTH OF GUATEMALA. THE TUTT LOW TO THE SOUTH IS FORECAST TO
BECOME BETTER ORGANIZED LATER ON TUESDAY-WEDNESDAY AS IT MEANDERS
ALONG THE PACIFIC COAST OF SOUTHERN MEXICO. EARLY IN THE CYCLE
THIS IS TO ENHANCE CONVECTION ACROSS THE NORTHWEST/CENTRAL
BAHAMAS...TO FAVOR RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF
10MM. ON TUESDAY...AS THE SUBTROPICAL RIDGE TO THE NORTH
STRENGTHENS ITS FOOTHOLD OVER THE GULF OF MEXICO...EXPECTING A
LULL IN ACTIVITY...WHILE ON WEDNESDAY ONCE AGAIN EXPECTING
RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF 10MM. OVER
CUBA...MOST ACTIVE IS EXPECTED ON WEDNESDAY-THURSDAY WITH RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM. OVER GUATEMALA-SOUTHERN
MEXICO INITIALLY EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-30MM...DECREASING TO 05-10MM/DAY AND MAXIMA OF
15-20MM ON TUESDAY. HIGHER AMOUNTS ARE EXPECTED ON WEDNESDAY AS A
TROPICAL WAVE STREAMS ACROSS CENTRAL AMERICA.

BROAD CELL OF THE SUBEQUATORIAL RIDGE TO THE SOUTH OF THIS TROUGH
DOMINATES THE FLOW ACROSS CENTRAL AMERICA-NORTHERN SOUTH AMERICA
AND THE CARIBBEAN BASIN. EARLY IN THE CYCLE THIS IS TO ANCHOR ON
TWO CLOSED HIGHS...WITH ONE CENTERING OVER THE GULF OF URABA AND
THE OTHER JUST WEST OF THE FRENCH ISLANDS. ON
TUESDAY-WEDNESDAY...A DEEPENING TROUGH OVER THE CENTRAL ATLANTIC
IS TO AMPLIFY INTO THE NORTHEAST CARIBBEAN. UNDER PRESSURE FROM
THIS TROUGH THE SEGMENT OF THE RIDGE OVER THE EASTERN CARIBBEAN IS
TO COLLAPSE...WHILE THE ONE TO THE WEST IS TO HOLD ACROSS CENTRAL
AMERICA-SOUTHERN CARIBBEAN-COLOMBIA. AS THE TROUGH DEEPENS ACROSS
THE NORTHEAST CARIBBEAN...EXPECTING THE SLOW AND GRADUAL EROSION
OF THE TRADE WINDS CAP. ON THURSDAY THE CAP WEAKENS AND
ENVIRONMENTAL CONDITIONS BECOME MORE FAVORABLE FOR DEEP CONVECTION
TO DEVELOP. THE SUBEQUATORIAL RIDGE...AS IT HOLDS TO THE
WEST...WILL VENT DEEP CONVECTION ACROSS CENTRAL AMERICA...WITH
ACTIVITY ACROSS HONDURAS-NORTHERN NICARAGUA TO SUSTAIN RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM. HIGHER AMOUNTS ARE
EXPECTED OVER SOUTHERN CENTRAL AMERICA...IN PARTICULAR COSTA
RICA...WHERE WE EXPECT RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA
OF 35-70MM. ON TUESDAY-WEDNESDAY THIS DECREASES TO 10-15MM/DAY AND
MAXIMA OF 20-40MM...WHILE ON THURSDAY EXPECTING RAINFALL AMOUNTS
OF 05-10MM/DAY AND MAXIMA OF 15-20MM. OVER PANAMA-NORTHERN/WESTERN
COLOMBIA EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM...WITH HIGHER AMOUNTS IN ASSOCIATION WITH TROPICAL WAVES.
OVER EASTERN COLOMBIA-SOUTHERN VENEZUELA...EXPECTING MODERATE TO
HEAVY CONVECTION TO SUSTAIN RAINFALL AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 30-60MM. ON TUESDAY AND ONWARD EXPECTING RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM. OVER THE GUIANAS
EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM.

TROPICAL/EASTERLY WAVES/TRADE WIND SURGES FROM 00 UTC:
INITIAL 24    36    48    60    72    84    96    TYPE      SOF
39W     44W   49W   54W   59W   64W   69W   74W    TW       27N
70W     74W   78W   83W   87W   91W   95W   99W    TW       23N
94W     97W  101W  104W  108W  111W   DISSIPATES   EW       18N

A TROPICAL WAVE ALONG 39W AND SOUTH OF 27N MOVES TO FRENCH GUIANA
EARLY ON TUESDAY MORNING...TO SUSTAIN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. THIS SPREADS ACROSS SURINAME
DURING THE DAY...MEANWHILE TRIGGERING SIMILAR RAINFALL AMOUNTS.
OVER GUYANA ALSO EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15-20MM...WHILE ACROSS VENEZUELA THIS WILL SUSTAIN
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-45MM. ACROSS THE
ISLAND CHAIN THIS WILL TRIGGER RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15-25MM ON WEDNESDAY...WITH SIMILAR AMOUNTS OVER PUERTO
RICO-HISPANIOLA ON THURSDAY.

A TROPICAL WAVE ALONG 70W AND SOUTH OF 23N IS TO TRIGGER ORGANIZED
CONVECTION ACROSS CENTRAL/WESTERN VENEZUELA TO EASTERN
COLOMBIA...TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
30-60MM. OVER NORTHWEST VENEZUELA/NORTHERN COLOMBIA THIS WILL
SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-45MM...WHILE OVER THE ABC ISLANDS EXPECTING RAINFALL AMOUNTS OF
00-05MM/DAY AND MAXIMA OF 10MM. ACROSS PUERTO RICO-HISPANIOLA THIS
WILL SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-30MM...WHILE OVER JAMAICA-EASTERN CUBA EXPECTING RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM ON TUESDAY-WEDNESDAY.
ACTIVITY BUILDS ACROSS PANAMA ON TUESDAY...TO FAVOR RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-30MM. OVER COSTA
RICA-SOUTHERN NICARAGUA THIS IS TO INTERACT WITH THE ITCZ IN
SUPPORT OF RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM.
ACROSS HONDURAS-BELIZE-GUATEMALA THIS IS TO THEN SUSTAIN RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM. ON THE SOUTHERN AND
CENTRAL STATES OF MEXICO EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY
AND MAXIMA OF 20-30MM ON THURSDAY.

AN EASTERLY WAVE ALONG 94W AND SOUTH OF 18N IS TO ENHANCE
CONVECTION ACROSS THE SOUTHWEST STATES OF MEXICO...TO FAVOR
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM.

HUDSON...MS (JAMAICA)
HERNANDEZ...IMTA (MEXICO)
WARD-FORBES...BDM (THE BAHAMAS)
DAVISON...WPC (USA)