National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXCA20 KWBC 171821
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
221 PM EDT MON JUN 17 2013

AT 15UTC TROPICAL DEPRESSION TWO CENTERED NEAR 16.2N 87.6W...WITH
CENTRAL PRESSURE OF 1008 HPA AND MAXIMUM SUSTAINED WINDS OF 30KT.
THE DEPRESSION IS MOVING TO THE WEST-NORTHWEST AT 11KT. SEE NHC
FORECAST FOR DETAILS.

DISCUSSION FROM JUNE 17/00UTC: AT UPPER LEVELS...A NARROW TROUGH
ACROSS THE GULF OF MEXICO/ISTHMUS OF TEHUANTEPEC SPLITS THE
SUBTROPICAL RIDGE IN TWO CELLS...ONE OVER BAJA PENINSULA/SOUTHERN
MEXICO AND THE OTHER OVER CENTRAL AMERICA/WESTERN CARIBBEAN. THIS
IS A SLOW TO EVOLVE PATTERN...WITH SLIGHT MODIFICATION LATER IN
THE CYCLE AS THE TROUGH ALIGNS ALONG 100W. MEANWHILE...RIDGE ALOFT
IS TO VENT DIURNAL CONVECTION ALONG THE SIERRA MADRE BETWEEN
SINALOA-SONORA IN WESTERN MEXICO...WITH RAINFALL AMOUNTS OF
00-05MM/DAY AND MAXIMA OF 10MM IN ISOLATED TO SCATTERED LATE
AFTERNOON/EARLY EVENING CONVECTION. THE TROUGH
ALOFT...MEANWHILE... AS IT ENHANCES CONVECTIVE INSTABILITY...IS TO
FAVOR SCATTERED CONVECTION. ACROSS CENTRAL MEXICO EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM/DAY. THROUGH
DAY 04 THIS IS TO GRADUALLY INCREASE AS MOISTURE SURGES IN
ASSOCIATION WITH TD-TWO.

THE WESTERN CARIBBEAN RIDGE...MEANWHILE...WILL PROVIDE THE
VENTILATION ALOFT TO TD-TWO AS IT TRACKS WEST ACROSS THE
YUCATAN-NORTHERN CENTRAL AMERICA TO THE SOUTHERN STATES OF MEXICO.
ACROSS BELIZE-GUATEMALA AND THE SOUTHERN STATES OF MEXICO THIS IS
TO FAVOR RAINFALL AMOUNTS OF 35-70MM/DAY AND MAXIMA OF
75-125MM/DAY THROUGH DAY 02. LOCALIZED HEAVIER AMOUNTS ARE
POSSIBLE ACROSS CENTRAL GUATEMALA TO TABASCO/CHIAPAS IN SOUTHERN
MEXICO DUE TO STRONG TOPOGRAPHICAL FORCING. CONVECTION TRAILING
THIS DEPRESSION IS TO ALSO AFFECT NORTHEAST HONDURAS/NICARAGUA
THROUGH 36 HRS WITH RAINFALL AMOUNTS OF 35-70MM/DAY AND MAXIMA OF
75-125MM. ON DAYS 03-04...THIS IS TO DECREASE TO 15-20MM/DAY AND
MAXIMA OF 25-50MM...WITH MOST INTENSE EXPECTED BETWEEN
VERACRUZ-NORTHERN OAXACA AND CENTRAL PORTIONS OF MEXICO.

ALSO...AS THE UPPER LEVEL RIDGE HOLDS ACROSS THE WESTERN
CARIBBEAN/CENTRAL AMERICA...IT WILL SUSTAIN THE SOUTHWARD
AMPLIFICATION OF A TUTT ACROSS PUERTO RICO/HISPANIOLA TO THE
EASTERN CARIBBEAN. A CLOSED LOW NEAR 23N 64W IS TO ANCHOR THIS
TROUGH OVER THE NEXT FEW DAYS. AT 500 HPA IT ALSO REFLECTS AS A
CLOSED CIRCULATION JUST NORTH OF THE ISLANDS. BUT THROUGH 36-48
HRS IT WILL WEAKEN TO AN INVERTED TROUGH. AT 60-72 HRS...AS A CELL
OF THE SUBEQUATORIAL RIDGE BUILDS ACROSS THE TROPICAL ATLANTIC...
IT WILL FORCE THE TUTT TO RETROGRESS TO HISPANIOLA-SOUTHEAST
BAHAMAS...WHILE BASE MEANDERS OVER/TOWARDS JAMAICA. ALTHOUGH THE
TUTT PATTERN IS WELL ESTABLISHED...THIS IS TO HAVE LITTLE IMPACT
ON LOCAL WEATHER CONDITIONS ACROSS THE NORTHEAST CARIBBEAN ISLES
OVER THE NEXT 36-48 HRS. FOR THE MOST PART...AS IT IS TO FAVOR
DENSE UPPER CLOUDS...THIS WILL TEND TO LIMIT...IF NOT
INHIBIT...SEA BREEZE CONVERGENCE. SOME POSITIVE INTERACTION IS
POSSIBLE ALONG THE BASE OVER THE SOUTHERN WINDWARD ISLANDS...WHERE
IN INTERACTION WITH THE ITCZ IT WILL RESULT IN RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-30MM. HIGHER RAINFALL AMOUNTS ARE
EXPECTED LATER IN THE CYCLE AS THE TUTT INTERACTS WITH A TROPICAL
WAVE IN THE LOW LEVEL EASTERLIES (SEE BELOW FOR DETAILS).

THE EASTERN PACIFIC ITCZ IS TO MEANDER WEST ALONG 10N ACROSS COSTA
RICA/PANAMA TO NORTHERN COLOMBIA. ACROSS PANAMA-COSTA RICA THIS IS
TO FAVOR RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM/DAY.
OVER NORTHERN COLOMBIA TO NORTHWEST VENEZULA EXPECTING RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM/DAY. EQUATORIAL
TROUGH CONVECTION OVER CENTRAL/NORTHERN VENEZUELA IS TO FAVOR
RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF 10MM/DAY. OVER THE
TROPICAL ATLANTIC...AS THE ITCZ MEANDERS ACROSS THE NORTHERN
GUIANAS TO NORTHEAST VENEZUELA...EXPECTING RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM/DAY.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC

INITIAL 24   36   48   60   72   84   TYPE
43W     44W  50W  55W  59W  64W  68W  TW

TROPICAL WAVE IS INITIALIZED ALONG 43W. A 35-40KT WIND SURGE
ASSOCIATES WITH THIS PERTURBATION. BY 36-48 HRS...AS IT MOVES
ACROSS GUYANA TO SURINAME IT WILL SUSTAIN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM/DAY. OVER NORTHERN GUYANA TO
NORTHEAST VENEZUELA/SOUTHERN WINDWARD ISLANDS IT IS TO THEN RESULT
IN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM/DAY...
WHILE OVER THE LEEWARD/FRENCH ISLANDS EXPECTING ACCUMULATION OF
10-15MM/DAY AND MAXIMA OF 20-40MM/DAY. OVER PUERTO RICO TO THE
DOMINICAN REPUBLIC...AS THE TROPICAL WAVE INTERACTS WITH THE
TUTT...EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-45MM/DAY. OVER VENEZUELA...IN INTERACTION WITH THE NEAR
EQUATORIAL TROUGH...EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15MM/DAY.

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