Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center
 
Tropical Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1822Z Oct 22, 2014)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
Abbreviations and acronyms used in this product


TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
222 PM EDT WED OCT 22 2014

AT 15 UTC...TD-NINE CENTERED NEAR 19.4N 92.4W...WITH MINIMAL
CENTRAL PRESSURE OF 1002 HPA AND MAXIMUM SUSTAINED WINDS OF 30KT.
SEE NHC BULLETIN FOR DETAILS.

DISCUSSION FROM OCTOBER 22/00UTC: IN A WEAK STEERING FLOW THE NHC
FORECASTS TD-NINE TO MEANDER EAST ACROSS THE YUCATAN PENINSULA TO
THE WESTERN CARIBBEAN THROUGH FRIDAY EVENING. THE SLOW TO EVOLVE
DEPRESSION IS TO CONTINUE FAVORING HEAVY RAINS ACROSS THE YUCATAN
PENINSULA/SOUTHERN STATES OF MEXICO. IN THIS AREA EXPECTING
RAINFALL AMOUNTS OF 35-70MM/DAY AND MAXIMA OF 150-200MM/DAY. NOTE
THAT STRONG TOPOGRAPHICAL FORCING ACROSS CAMPECHE-TABASCO-CHIAPAS
WOULD LIKELY RESULT IN EXTREME RAINFALL AMOUNTS WITH MAXIMA OF
NEARLY 400MM. AS THE DEPRESSION MOVES TO THE WESTERN
CARIBBEAN...AND NORTHERLIES EXPAND INTO HONDURAS/CENTRAL
GUATEMALA...THIS IS TO THEN FAVOR RAINFALL AMOUNTS OF 20-40MM/DAY
AND MAXIMA OF 75-150MM.

AT MID/UPPER LEVELS A DEEP POLAR TROUGH DOMINATES THE FLOW ACROSS
THE EASTERN USA/FAR WESTERN ATLANTIC TO THE EASTERN GULF OF
MEXICO/FLORIDA PENINSULA. THROUGH THURSDAY EVENING THE TROUGH IS
TO SLOWLY PULL TO THE EAST-NORTHEAST AS ANOTHER TROUGH APPROACHES
FROM THE WEST. THE LATTER IS TO MOVE TO THE EASTERN USA-NORTHERN
GULF OF MEXICO LATER ON FRIDAY. AS IT MOVES TO THE EASTERN USA...A
SUBTROPICAL JET MAXIMA IS TO THEN ROUND THE BASE OF THE
TROUGH...WITH DIVERGENCE ON ITS RIGHT ENTRANCE REGION TO ENVELOP
WESTERN CUBA AND THE NORTHWEST-CENTRAL BAHAMAS. AT LOW LEVELS THE
TROUGH SUSTAINS A POLAR FRONT THAT MOVES ACROSS THE NORTHWEST
BAHAMAS-SOUTH FLORIDA TO THE GULF OF MEXICO EARLY ON THURSDAY
MORNING. THE FRONT IS TO THEN REMAIN NEARLY STATIONARY THROUGH
FRIDAY MORNING. IT IS TO THEN UNDULATE SOUTH TO THE NORTHERN
YUCATAN WHILE MEANDERING OVER THE NORTHWEST BAHAMAS LATER IN THE
DAY. THROUGH SATURDAY EVENING THE FRONT MEANDERS ACROSS THE
CENTRAL BAHAMAS-CENTRAL/WESTERN CUBA WHILE TRAILING TO THE
NORTHERN YUCATAN. MOISTURE ADVECTING FROM TD-NINE IS TO THEN
CONVERGE ALONG THIS FRONT...TO RESULT IN AREAS OF STRONG
DYNAMICAL/MECHANICAL FORCING AND POTENTIALLY SEVERE CONVECTION AS
CONDITIONS BECOME FAVORABLE FOR MCS FORMATION. ACROSS WESTERN CUBA
EXPECTING RAINFALL AMOUNTS OF 15-30MM/DAY AND MAXIMA OF 40-80MM
THROUGH THURSDAY MORNING...AND 35-70MM/DAY AND MAXIMA OF 75-150MM
THROUGH FRIDAY EVENING. OVER THE NORTHWEST BAHAMAS EXPECTING
RAINFALL AMOUNTS OF 15-30MM/DAY AND MAXIMA OF 40-80MM ON THURSDAY
TO FRIDAY...AND 50-75MM/DAY AND MAXIMA OF 150-200MM ON SATURDAY TO
SUNDAY.

FURTHERMORE...TD-NINE...AS IT MEANDERS OVER THE SOUTHERN
GULF...SUSTAINS A SOUTHWESTERLY FLOW ACROSS THE SOUTHERN STATES OF
MEXICO TO CENTRAL AMERICA. THIS FAVORS THE NORTHWARD MODULATION OF
THE EASTERN PACIFIC ITCZ ALONG THE SOUTH COAST OF
MEXICO-GUATEMALA/EL SALVADOR TO NORTHERN NICARAGUA. AT UPPER
LEVELS...BUILDING RIDGE IS TO EXPAND FROM SOUTHERN MEXICO TO THE
CENTRAL CARIBBEAN EARLY IN THE CYCLE. THROUGH THURSDAY EVENING THE
RIDGE IS TO BUILD ACROSS THE BASIN TO THE NORTHEAST CARIBBEAN
ISLANDS. EARLY IN THE CYCLE THE RIDGE IS TO ANCHOR ON TWO CLOSED
HIGHS...WITH ONE OVER SOUTHERN MEXICO AND THE OTHER NEAR THE
CAYMAN ISLANDS. THROUGH FRIDAY MORNING THE ONE OVER MEXICO WEAKENS
WHILE THE ONE NEAR THE CAYMAN ISLES IS TO STRENGTHEN. THE RIDGE
ALOFT IS TO VENT DEEP CONVECTION ALONG THE CONVERGENCE ZONE.
ACROSS GUATEMALA-EL SALVADOR/SOUTHERN HONDURAS TO WESTERN
NICARAGUA THIS IS TO FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND
MAXIMA OF 25-50MM THROUGH THURSDAY. THEREAFTER EXPECTING RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-30MM. AS THE ITCZ MEANDERS
OVER THE SOUTHERN CARIBBEAN/NORTH OF PANAMA DIURNAL CONVECTION IS
TO GENERALLY CLUSTER ALONG THE CONTINENTAL DIVIDE...WITH RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM.

EAST OF THE SUBTROPICAL RIDGE...AT 250 HPA...A TUTT EXTENDS FROM
THE NORTHEAST CARIBBEAN TO THE GULF OF URABA/NORTH OF PANAMA. AS
THE RIDGE ALOFT EXPANDS ACROSS THE NORTHERN CARIBBEAN THIS IS TO
CONTINUE PUSHING THE TROUGH EAST. THROUGH THURSDAY MORNING THE
TROUGH IS TO MIGRATE FARTHER EAST ACROSS THE WINDWARD ISLANDS TO
NORTHERN VENEZUELA...WHERE IT IS TO REMAIN THROUGH THE END OF THE
WEEK WHILE GRADUALLY BECOMING BETTER ORGANIZED. AS THE TROUGH
MEANDERS EAST ACROSS NORTHERN VENEZUELA IT IS TO INTERACT WITH THE
NEAR EQUATORIAL TROUGH TO THE SOUTH...TO TRIGGER SCATTERED
CONVECTION WITH ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15-30MM.
HIGHER AMOUNTS ARE EXPECTED ACROSS AMAZONIA TO THE SOUTH...WITH
MAXIMA OF 20-40MM. FURTHERMORE...AS THE TROUGH ALOFT MEANDERS
ACROSS THE WINDWARD ISLES...IT IS TO INTERACT WITH THE ATLANTIC
ITCZ. THIS IS TO CONTINUE FAVORING SCATTERED DEEP CONVECTION WITH
RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-35MM. ON SATURDAY
THIS DECREASES TO 05-10MM/DAY AND MAXIMA OF 15-25MM. ACROSS
COLOMBIA TO THE WEST...DIURNAL CONVECTION IS TO GENERALLY FAVOR
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-30MM.
HOWEVER...IN A LIGHT WESTERLY LOW LEVEL FLOW...GLOBAL MODEL
GUIDANCE SHOWING LOCALIZED MAXIMA IN EXCESS OF 40MM CLUSTERING
OVER THE ANDES.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
38W     40W    42W    44W    46W    49W    52W    54W     TW
59W     61W    63W    65W    67W    69W    71W    73W     TW

TROPICAL WAVE ALONG 38W REACHES FRENCH GUIANA LATER ON FRIDAY...TO
FAVOR SCATTERED CONVECTION WITH ACCUMULATION OF 00-05MM/DAY IN
ISOLATED CONVECTION.

TROPICAL WAVE ALONG 59W IS TO INTERACT WITH TUTT ALOFT AS IT
ENTERS THE WINDWARD ISLES/ORINOCO DELTA REGION IN VENEZUELA EARLY
IN THE CYCLE...TO SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND
MAXIMA OF 20-40MM. OVER EASTERN-CENTRAL VENEZUELA...IN INTERACTION
WITH THE EQUATORIAL TROUGH...EXPECTING RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM...WITH SIMILAR AMOUNTS ACROSS
THE ABC ISLANDS. LATER ON FRIDAY...AS IT ENTERS NORTHWEST
VENEZUELA/ NORTHERN COLOMBIA...IT IS TO FAVOR RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM/DAY.

JN BAPTISTE...MS (SAINT LUCIA)
MEDINA...ONAMET (REPUBLICA DOMINICANA)
DAVISON...WPC (USA)