TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
222 PM EDT WED JUN 19 2013

AT 15UTC TROPICAL DEPRESSION TWO CENTERED NEAR 19.6N 94.5W...WITH
CENTRAL PRESSURE OF 1006 HPA AND MAXIMUM SUSTAINED WINDS OF 30KT.
THE DEPRESSION IS MOVING TO THE WEST AT 08KT. SEE NHC FORECAST FOR
DETAILS.

DISCUSSION FROM JUNE 19/00UTC: AT 250 HPA...OVER WESTERN PORTIONS
OF THE DOMAIN...A TROUGH OVER CENTRAL MEXICO SPLITS THE
SUBTROPICAL RIDGE IN TWO CELLS...WITH THE WESTERNMOST TO DOMINATE
FLOW ACROSS THE BAJA PENINSULA/NORTHERN MEXICO AND THE EASTERNMOST
THE AREA OVER CENTRAL AMERICA/SOUTHERN MEXICO. THE TROUGH LIES
SOUTH ALONG 100W TO A CLOSED LOW OFF THE COAST OF GUERRERO IN
MEXICO. THIS LOW/TROUGH IS CUT OFF FROM THE FLOW...AND AS SUCH IT
IS EXPECTED TO GRADUALLY WEAKEN/FILL THROUGH 30-36 HRS. AS THE
TROUGH FILLS...THE RIDGES ARE TO COMBINE INTO A BROAD CELL ACROSS
MEXICO-CENTRAL AMERICA. THIS IS TO THEN PERSIST THROUGH 72-96 HRS.
THE TROUGH/LOW...AS IT MEANDERS OFF THE COAST OF MEXICO...WILL
ENHANCE CONVECTIVE DEVELOPMENT ACROSS SOUTHERN GUERRERO/OAXACA
EARLY IN THE CYCLE...TO FAVOR RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-40MM/DAY. OTHER ACTIVITY ALONG THE SIERRA MADRE
OCCIDENTAL WILL RESULT IN RAINFALL AMOUNTS OF 00-05MM/DAY AND
WIDELY ISOLATED MAXIMA OF 10MM. THE RIDGE ALOFT IS TO ALSO VENT
DEEP CONVECTION ACROSS NORTHERN CENTRAL AMERICA TO SOUTHERN
MEXICO...WITH RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-25MM TO CLUSTER ALONG THE CONTINENTAL DIVIDE.

THE RIDGE ALOFT IS TO ALSO VENT DEEP CONVECTION IN ASSOCIATION
WITH TD-TWO. THE NHC IS FORECASTING THIS SYSTEM TO STRENGTHEN TO A
TROPICAL STORM BEFORE MAKING LANDFALL OVER VERACRUZ MEXICO. IN
THIS AREA THIS IS TO SUSTAIN RAINFALL AMOUNTS OF 20-40MM/DAY AND
MAXIMA OF 50-100MM/DAY. THIS WILL SPREAD WEST INTO CENTRAL MEXICO
THROUGH 72 HRS...WITH RAINFALL AMOUNTS DECREASING TO 10-15MM/DAY
AND MAXIMA OF 20-35MM/DAY AS THE STORM WEAKENS TO A REMNANT
LOW/TROUGH.

FARTHER EAST...A TUTT LOW NORTH OF THE ISLANDS EXTENDS A TROUGH
SOUTH ACROSS PUERTO RICO/EASTERN HISPANIOLA TO THE EASTERN
CARIBBEAN. THE TROUGH IS INTERACTING WITH A TROPICAL WAVE AND THE
ATLANTIC ITCZ...SUSTAINING A MOIST PLUME ACROSS THE ISLANDS. UNDER
INFLUENCE OF A BUILDING CELL OF THE SUBEQUATORIAL RIDGE TO THE
EAST...THE TUTT HAS STARTED TO RETROGRESS. THROUGH 42-48 HRS IT IS
TO RELOCATE ACROSS HISPANIOLA-CENTRAL CARIBBEAN...WHILE MID/UPPER
LEVEL RIDGE ESTABLISHES A FOOTHOLD ACROSS THE EASTERN CARIBBEAN.
THE RETROGRESSING TUTT IS TO FAVOR AN UPPER DIVERGENT PATTERN
ACROSS THE ISLAND CHAIN TO PUERTO RICO EARLY THIS CYCLE...SHIFTING
ACROSS HISPANIOLA THROUGH 42-48 HRS. BY 60-72 HRS THIS IS TO
EXPAND TO ALSO INCLUDE JAMAICA AND THE SOUTHEAST BAHAMAS/TURKS.
BUT AS THE RIDGE BUILDS...A MID/UPPER CONVERGENT PATTERN IS TO
THEN ESTABLISH ACROSS THE ISLAND CHAIN TO PUERTO RICO THROUGH 36
HRS. ALONG THE BASE OF THE TROUGH...AS IT MEANDERS OVER NORTHERN
COLOMBIA/NORTHWEST VENEZUELA...THIS IS TO ENHANCE CONVECTION ALONG
THE NEAR EQUATORIAL TROUGH.

ITCZ CONVERGENCE ACROSS SOUTHERN NICARAGUA-COSTA RICA-PANAMA IS TO
RESULT IN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM.
OVER NORTHERN COLOMBIA...THE NEAR EQUATORIAL TROUGH AS IT
INTERACTS WITH THE TUTT WILL SUSTAIN RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 25-50MM THROUGH 60 HRS...AND 10-15MM/DAY
AND MAXIMA OF 20-35MM/DAY THEREAFTER. ACROSS THE NORTHERN
GUIANAS...AS THE ITCZ MEANDERS SOUTH ALONG THE NORTH COAST BY
24-36 HRS...EXPECTING SCATTERED CONVECTION ALONG THE NORTH COAST
TO RESULT IN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM/DAY. THROUGH 72-84 HRS THIS DECREASES TO 05-10MM/DAY AND
MAXIMA OF 15MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC

INITIAL 24   36   48   60   72   84   TYPE
61W     66W  70W  74W  78W  81W  85W  TW

TROPICAL WAVE IS INITIALIZED ALONG 61W. THE WAVE IS IN PHASE WITH
THE TUTT. ACROSS THE VIRGIN ISLES TO PUERTO RICO-EASTERN
HISPANIOLA IT IS TO SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-45MM/DAY. BY 36-48 HRS THIS WILL INCREASE TO
15-20MM/DAY AND MAXIMA OF 25-50MM AS CONVECTION FLARES UP ACROSS
THE DOMINICAN REPUBLIC. CONVECTION IS TO THEN SPREAD TO THE
SOUTHEAST BAHAMAS/TURKS-EASTERN CUBA THROUGH 48 HRS...WITH
ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15MM/DAY. OVER JAMAICA
IT IS TO RESULT IN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM/DAY. ACROSS THE CAYMAN ISLES IT IS TO THEN FAVOR RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM...WHILE OVER THE
CENTRAL-NORTHWEST BAHAMAS EXPECT ACCUMULATION OF 05-10MM/DAY AND
MAXIMA OF 15-20MM LATER IN THE CYCLE. OVER SOUTH AMERICA MOST
ACTIVE IS EXPECTED OVER NORTHWEST VENEZUELA-NORTHERN COLOMBIA
WHERE IT IS TO SUSTAIN RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA
OF 25-50MM/DAY. ACROSS PANAMA TO COSTA RICA AND EASTERN
NICARAGUA/NORTHEAST HONDURAS EXPECTING ACCUMULATION OF 05-10MM/DAY
AND MAXIMA OF 15-25MM/DAY.

MCKENZIE...BDM (BAHAMAS)
ROBINSON...MSJ (JAMAICA)
DAVISON...WPC (USA)