THE WEATHER PREDICTION CENTER

COLLEGE PARK, MD


CARIBBEAN FORECAST DISCUSSION




TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
251 PM EDT FRI OCT 19 2018

AT 18 UTC...TROPICAL DEPRESSION TWENTY-THREE-E CENTERED AT 13.3N
91.9W. MINIMUM CENTRAL PRESSURE IS 1006 HPA AND MAXIMUM SUSTAIN
WINDS OF 30KT. THE DEPRESSION IS MOVING TO THE WEST-NORTHWEST AT
02KT.

TROPICAL DISCUSSION FROM OCT 19/12 UTC: TROPICAL DEPRESSION TWENTY
THREE-E HAS FORMED TO THE SOUTH OF GUATEMALA...AND NHC HAS THE
SYSTEM MEANDERING TO THE WEST-NORTHWEST THROUGH THE CYCLE. THE
SYSTEM HAS FORMED IN THE BASE OF AN EASTERLY WAVE (SEE
BELOW)...AND AS IT ENHANCES NORTHEASTERLY FLOW IN THE SOUTHERN
GULF OF MEXICO WHERE A DEEP MOIST POOL EXISTS...IT WILL FAVOR
LOCALLY HEAVY RAINFALL. THROUGH EARLY SATURDAY...EXPECTING MAXIMA
OF 25-50MM/DAY IN VERACRUZ/OAXACA AND MAXIMA OF 35-70MM/DAY IN
SOUTHERN GUATEMALA...THE LATTER STIMULATED BY ONSHORE FLOW IN THE
PERIPHERY OF THE TROPICAL DEPRESSION. BY
SATURDAY-SUNDAY...EXPECTING A PEAK IN PRECIPITATION TO SUSTAIN
25-50MM/DAY AND MAXIMA OF 75-125MM...WITH LARGEST ACCUMULATIONS
CLUSTERING IN VERACRUZ. BY SUNDAY-MONDAY...LARGEST AMOUNTS WILL
CONTINUE CLUSTERING IN VERACRUZ AIDED BY ANOTHER EASTERLY WAVE AND
CONTINUED ENHANCED MOISTURE CONVERGENCE...TO PRODUCE MAXIMA OF
35-70MM. LESSER AMOUNTS ARE EXPECTED IN THE PACIFIC COAST AS AN
OFFSHORE TRADE WIND COMPONENT WILL BE DOMINANT.

ALSO IN MEXICO...ANOTHER SURFACE FRONT WILL LEAD TO LARGE VALUES
OF MOISTURE CONVERGENCE IN THE RIO BRAVO REGION ONCE AGAIN. THIS
WILL SUSTAIN MAXIMA OF 15-25MM/DAY IN INTERIOR PORTIONS OF
NORTHWEST MEXICO...BUT ISOLATED MAXIMA OF 25-50MM/DAY ALONG
COASTAL AREAS OF TAMAULIPAS.

TO THE EAST...DRYING TREND IN THE CARIBBEAN CONTINUES UNDER THE
INFLUENCE OF A ROBUST MID-LEVEL RIDGE. THIS WILL CONSTRAIN
ACCUMULATIONS TO NORTHEASTERN SLOPES IN THE GREATER ANTILLES TO
PRODUCE ACCUMULATIONS OF 00-05MM/DAY AND MAXIMA OF 10MM...ALTHOUGH
ISOLATED LARGER AMOUNTS ARE POSSIBLE IN REGIONS OF ENHANCED
OROGRAPHIC FORCING.

A MORE ACTIVE PATTERN OF CONVECTION IS EXPECTED IN THE WINDWARD
ISLANDS AND NORTHERN SOUTH AMERICA...AS THE UPPER TROUGH TO THE
EAST OF THE LEEWARD ISLANDS DEEPENS AND EXTENDS ITS AXIS INTO
NORTHERN SOUTH AMERICA. THIS WILL INTERACT WITH ITCZ CONVECTION TO
SUSTAIN MODERATE ACCUMULATIONS. FURTHERMORE...THE UPPER TROUGH
WILL INDUCE A WELL DEFINED TROUGH THAT WILL LINGER ACROSS THE
WINDWARD ISLANDS/ORINOQUIA THROUGH THE CYCLE...TO SUSTAIN MODERATE
PRECIPITATION. LARGEST AMOUNTS ARE EXPECTED ON FRIDAY WHEN MAXIMA
WILL REACH 25-50MM/DAY IN MOST OF VENEZUELA...AND EXTENDING INTO
THE ABC. BY SATURDAY-SUNDAY EXPECTING MAXIMA OF 20-35MM/DAY IN
MOST OF VENEZUELA...EXTENDING INTO MONDAY. FURTHER WEST...ACTIVE
CONVECTION WILL ALSO DEVELOP IN COLOMBIA ON A DAILY BASIS. ON
FRIDAY...UNDER THE INFLUENCE OF A DISSIPATING TROPICAL
WAVE...EXPECTING ACCUMULATIONS OF 10-15MM/DAY AND MAXIMA OF
20-40MM. BY SATURDAY-SUNDAY...EXPECTING MAXIMA OF 25-50MM/DAY IN
NORTHERN COLOMBIA...YET IN NORTHWESTERN COLOMBIA AND THE CHOCO
EXPECTING MAXIMA OF 20-40MM. BY SUNDAY-MONDAY...LARGEST AMOUNTS
ARE EXPECTED IN WESTERN COLOMBIA AIDED Y ENHANCED WESTERLIES IN
THE LOW-LEVELS...TO SUSTAIN MAXIMA OF 25-50MM/DAY. IN NORTHERN
COLOMBIA EXPECTING MAXIMA OF 20-40MM.

IN SOUTHERN CENTRAL AMERICA...DIURNAL CONVECTION IS EXPECTED ON A
DAILY BASIS. IN COSTA RICA AND PANAMA EXPECTING AN INCREASING
TREND IN ACCUMULATIONS FROM MAXIMA OF 15-25MM ON FRIDAY TO MAXIMA
OF 20-40MM/DAY ON SUNDAY. A REVERSE TREND IS EXPECTED IN NORTHERN
PORTIONS OF CENTRAL AMERICA...AS A DRY AIR MASS ARRIVES FROM THE
CARIBBEAN. THIS WILL SUSTAIN MAXIMA OF 20-30MM/DAY
INITIALLY...DECREASING TO MAXIMA OF 15-20MM/DAY BY SATURDAY...WITH
CONVECTION BECOMING ISOLATED AFTER.

TROPICAL/EASTERLY WAVES/TRADE WIND SURGES FROM 00 UTC:
INITIAL 24    36    48    60    72    84    96    TYPE     SOF
75W    77W   79W   DISS                            TW      15N   
83W    86W   90W   93W   96W   98W  100W  103W    I/EW     23N   
89W    93W   96W   98W  101W  104W  107W  110W     EW      25N

A TROPICAL WAVE IS INITIALIZED AT 75W BUT IS DISSIPATING AS UPPER
TROUGH PATTERN AND PANAMANIAN LOW PATTERN BECOME THE DOMINANT
FEATURES IN NORTHERN SOUTH AMERICA.

AN EASTERLY WAVE IS INITIALIZED AT 83W AND WILL ENHANCE CONVECTION
ACROSS THE YUCATAN PENINSULA ON FRIDAY...SOUTHERN MEXICO ON
SATURDAY...AND CENTRAL MEXICO ON SUNDAY.

AN EASTERLY WAVE PROPAGATING ALONG 89W HAS AIDED THE DEVELOPMENT
OF TROPICAL DEPRESSION TWENTY THREE-E. THE ASSOCIATED WAVE WILL
ENHANCE ACTIVITY ACROSS MEXICO THROUGH THE CYCLE AS IT PROPAGATES
FROM TABASCO/CHIAPAS ON FRIDAY...TO CENTRAL MEXICO BY SUNDAY.

SERNA...IDEAM (COLOMBIA)
TEJADA...AAC (PANAMA)
GALVEZ...WPC (USA)      




Last Updated: 251 PM EDT FRI OCT 19 2018