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000
FXCA20 KWBC 251850
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
150 PM EST TUE NOV 25 2014

NOTE: TROPICAL DESK PRODUCTS WILL NOT BE AVAILABLE ON NOV 27-28.

DISCUSSION FROM NOVEMBER 25/00UTC: HIGH AMPLITUDE TROUGH NOW
EXTENDS ACROSS THE CENTRAL USA TO THE NORTHERN STATES OF
MEXICO/NORTHWEST GULF. THROUGHOUT THE DAY ON WEDNESDAY THE TROUGH
BEGINS TO LIFT OVER A RIDGE TO THE EAST... WITH BASE OF THE TROUGH
TO RAPIDLY PULL ACROSS THE GULF OF MEXICO TO THE EASTERN USA.
LATER ON THURSDAY IT PULLS FARTHER NORTH AS IT ENTERS THE WESTERN
ATLANTIC. AT LOW LEVELS...THE ASSOCIATED FRONT EXTENDS ACROSS
NORTHERN FLORIDA-GULF OF MEXICO TO THE STATE OF VERACRUZ. FRONTAL
NORTHERLIES OF 25-35KT ARE TO DISPLACE THIS BOUNDARY SOUTH ACROSS
THE FLORIDA PENINSULA TO THE FLORIDA KEYS EARLY ON
WEDNESDAY...WHILE THE TRAILING END RACES ACROSS THE GULF/YUCATAN
PENINSULA TO BELIZE/NORTHWEST CARIBBEAN. LATER ON WEDNESDAY TO
EARLY THURSDAY MORNING THE FRONT MOVES ACROSS THE NORTHWEST TO THE
CENTRAL BAHAMAS...TRAILING ACROSS CENTRAL CUBA TO THE GULF OF
HONDURAS/BELIZE. EARLY ON FRIDAY THE FRONT MOVES TO THE SOUTHEAST
BAHAMAS/TURKS AND CAICOS...TRAILING ACROSS EASTERN CUBA...THE
CAYMAN ISLES TO BELIZE. BRISK FRONTAL NORTHERLIES OVER THE
NORTHWEST CARIBBEAN ARE TO PERSIST THROUGH FRIDAY EVENING. THESE
ARE TO INITIALLY ENHANCE MOISTURE CONVERGENCE ACROSS SOUTHERN
MEXICO-CENTRAL GUATEMALA...AND ACROSS NORTHERN HONDURAS ON
WEDNESDAY AND ONWARD. FURTHERMORE...AS THE FRONT SURGES ACROSS
CUBA IT IS TO TRIGGER A PREFRONTAL SHEAR LINE LATER ON WEDNESDAY.
THIS IS TO EXTEND ACROSS THE CENTRAL BAHAMAS-CENTRAL CUBA TO
NORTHEAST NICARAGUA. THROUGH THURSDAY EVENING THIS WILL MOVE TO
THE TURKS AND CAICOS/WINDWARD PASSAGE OF CUBA...TRAILING ACROSS
JAMAICA TO SOUTHERN NICARAGUA/COSTA RICA. AS IT MOVES ACROSS
CENTRAL AMERICA...THE NORTHERLIES WILL SURGE AND ARE EXPECTED TO
PEAK AROUND 35-45KT OVER NICARAGUA.

ON THE SOUTHERN STATES OF MEXICO-CENTRAL GUATEMALA...THE STRONG
FRONTAL NORTHERLIES WILL SUSTAIN RAINFALL AMOUNTS OF 25-50MM/DAY
AND MAXIMA OF 75-100MM...WITH MOST INTENSE OVER MEXICO TO CLUSTER
BETWEEN SOUTHERN VERACRUZ AND TABASCO/CHIAPAS. ON THE
NORTHWEST-CENTRAL BAHAMAS THE FRONT IS TO SUSTAIN RAINFALL AMOUNTS
OF 05-10MM/DAY AND MAXIMA OF 15-20MM...WHILE OVER CUBA EXPECTING
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-30MM. MOST
INTENSE OVER NORTHERN CENTRAL AMERICA IS EXPECTED BETWEEN PUERTO
BARRIOS GUATEMALA-LA CEIBA IN HONDURAS...WHERE STRONG
TOPOGRAPHICAL FORCING IS TO RESULT IN RAINFALL AMOUNTS OF
50-75MM/DAY AND MAXIMA OF 150-250MM/DAY THROUGH FRIDAY. SHEAR LINE
RELATED CONVECTION IS TO THEN CLUSTER ACROSS SOUTHERN NICARAGUA TO
COSTA RICA...WHERE THIS IS TO SUSTAIN RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-40MM. OVER THE CAYMAN ISLANDS AND
JAMAICA THIS IS TO RESULT IN RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15MM.

AMPLIFYING POLAR TROUGH PATTERN TO THE NORTH WILL SUSTAIN
INTENSIFICATION OF AN INDUCED/INVERTED TROUGH ACROSS THE CENTRAL
CARIBBEAN AND THE PANAMANIAN LOW OVER THE EASTERN PACIFIC.
THIS...IN-TURN...IS TO SUSTAIN A SURGE IN CONVECTION ACROSS
WESTERN COLOMBIA...WHERE WE EXPECT RAINFALL AMOUNTS OF 15-20MM/DAY
AND MAXIMA OF 25-50MM. BUT AS THE NORTHERLIES SURGE ACROSS THE
BASIN AND THE LOW WEAKENS THIS DECREASES TO 05-10MM/DAY AND MAXIMA
OF 15-20MM. ACROSS COSTA RICA/PANAMA DIURNAL CONVECTION IS TO
SUSTAIN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM...WITH THE MOST INTENSE EXPECTED ALONG THE CONTINENTAL
DIVIDE.

EAST OF THE POLAR TROUGH...A MID/UPPER LEVEL RIDGE DOMINATES THE
FLOW ACROSS THE CARIBBEAN/WESTERN ATLANTIC. STRONG RIDGE PATTERN
IS FORECAST IS TO PERSIST THROUGH EARLY ON WEDNESDAY. IT THEN
STARTS TO ERODE AS THE POLAR TROUGH LIFTS OVER THIS AXIS LATER IN
THE DAY. LATER ON THURSDAY THE RIDGE COLLAPSES OVER THE WESTERN
NORTH ATLANTIC...WHILE A LOW AMPLITUDE RIDGE IS TO THEN CONFINE TO
THE CARIBBEAN/GREATER ANTILLES. MEANWHILE THIS IS TO CONTINUE
FAVORING A FAIRLY STRONG CAP INVERSION ACROSS THE NORTHERN
CARIBBEAN ISLES AS WELL AS OVER THE LESSER ANTILLES. AT LOW
LEVELS...A BROAD RIDGE OVER THE WESTERN NORTH ATLANTIC SUSTAINS A
BRISK EASTERLY FLOW ACROSS THE ISLAND CHAIN TO THE CARIBBEAN
BASIN. UNDER PRESSURE FROM THE POLAR TROUGH TO THE WEST THIS IS
ALSO FORECAST TO GRADUALLY WEAKEN AS THE CYCLE PROGRESSES...WITH
STRONG EASTERLY TRADES EARLY IN THE CYCLE FORECAST TO WEAKEN
THROUGH THURSDAY MORNING. THE BRISK EASTERLY TRADES ARE TO FAVOR
GENERATION OF TRADE WIND SHOWERS AND LIGHT CONVECTION ACROSS THE
NORTHEAST CARIBBEAN ISLES.

DOWNSTREAM FROM THE SUBTROPICAL RIDGE...A TUTT NOW EXTENDS ACROSS
THE CENTRAL ATLANTIC TO THE EASTERN CARIBBEAN/NORTHERN VENEZUELA.
THE TUTT IS TO GRADUALLY STRENGTHEN THROUGH WEDNESDAY EVENING AS
THE RIDGE TO THE WEST STEERS SUCCESSIVE VORTICES AROUND THE
AMPLIFYING LONG WAVE TROUGH. THROUGH EARLY THURSDAY A CLOSED LOW
IS TO FORM JUST EAST OF THE LEEWARD ISLANDS... WHILE THE BASE OF
THE TROUGH MEANDERS ACROSS THE EASTERN CARIBBEAN TO NORTHERN
VENEZUELA. A FINGER OF THE SUBTROPICAL JET IS TO BOUND THE
NORTHERN PERIPHERY OF THE TROUGH...WITH ITS DIVERGENT LEFT EXIT
REGION (INDIRECT) TO MOVE JUST NORTH OF THE VIRGIN ISLES/PUERTO
RICO LATER THIS EVENING/EARLY WEDNESDAY. ANOTHER JET IS TO BOUND
THE SOUTHERN PERIPHERY OF THE TROUGH... WITH ITS RIGHT ENTRANCE
(DIVERGENT/DIRECT) OVER NORTHERN GUYANA. LATER ON THURSDAY...AS
RIDGE TO THE WEST FLATTENS...THE TUTT WILL BEGIN TO PULL TO THE
EAST-NORTHEAST. MEANWHILE...THIS IS TO ENHANCE CONVECTION ALONG
THE NEAR EQUATORIAL TROUGH OVER VENEZUELA...WITH TO THE SOUTH
EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-30MM...WHILE OVER NORTHERN GUYANA EXPECTING ACCUMULATION OF
10-15MM/DAY AND MAXIMA OF 20-30MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE
49W     52W    54W    56W    59W    62W    66W    68W   TUTT INDCD

TUTT ALOFT SUSTAINS INDUCED TROUGH IN THE EASTERLY TRADES WITH
AXIS NORTH-NORTHWEST ACROSS 49W. MOST ACTIVE CONVECTION WITH THIS
FEATURE IS EXPECTED TO THE NORTH OF 10N...TO AFFECT THE LESSER
ANTILLES EARLY ON THURSDAY AND ACROSS THE VIRGIN ISLES TO PUERTO
RICO LATER ON THURSDAY...WITH ACCUMULATION OF 00-05MM/DAY AND
MAXIMA OF 10MM.

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







000
FXCA20 KWBC 251153
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
653 AM EST TUE NOV 25 2014

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. TUTT PATTERN
TO THE EAST OF THE ISLANDS CONTINUES TO STRENGTHEN AS A HIGH
AMPLITUDE RIDGE CONTINUES TO HOLD TO THE WEST. THE RIDGE ENVELOPS
MOST OF THE CARIBBEAN BASIN AND THE WESTERN ATLANTIC. AT LOW
LEVELS...BROAD RIDGE OVER THE CENTRAL TO WESTERN NORTH ATLANTIC
FAVORS A BRISK EASTERLY FLOW ACROSS THE CARIBBEAN BASIN...WITH
TRADE WIND SHOWERS PESTERING THE FORECAST AREA.

UNDER PRESSURE FROM A POLAR TROUGH OVER THE USA...MID/UPPER LEVEL
RIDGE IS TO GRADUALLY FLATTEN THROUGH THURSDAY MORNING. AS THE
RIDGE EVOLVES...TUTT IS TO MEANDER WEST INTO THE EASTERN
CARIBBEAN...WITH A SUBTROPICAL JET MAXIMA ALONG THE WESTERN
FRINGES TO MOVE JUST NORTH OF THE FORECAST AREA LATER ON
WEDNESDAY/EARLY THURSDAY MORNING. DIVERGENCE ON ITS LEFT EXIT
REGION IS LIKELY TO ENHANCE CONVECTIVE DEVELOPMENT ACROSS PUERTO
RICO AND THE NORTHERN VI...WITH GFS SHOWING A WEAKER TRADE WINDS
CAP ACROSS THE FORECAST AREA DURING THE DAY ON THURSDAY. OTHER
ENHANCEMENT IS POSSIBLE AS SHORT WAVE VORTICES REVOLVE AROUND THE
MEANDERING MID LEVEL LOW. EARLY ON FRIDAY THE TUTT IS TO FILL
WHILE MERGING INTO POLAR TROUGH TO THE NORTH.

AT LOW LEVELS...TUTT ALOFT IS TO SUSTAIN AN INDUCED PERTURBATION
IN THE EASTERLY TRADES. THIS MOVES ACROSS THE LEEWARD ISLANDS
EARLY ON THURSDAY... AND THROUGH FRIDAY MORNING IT MOVES ACROSS
THE VIRGIN ISLES TO EASTERN PUERTO RICO...WHERE IT IS FORECAST TO
GRADUALLY FILL/WEAKEN. IN THIS PATTERN...WE EXPECT AN INCREASE IN
TRADE WIND SHOWERS ACTIVITY ACROSS THE VIRGIN ISLES-EASTERN PUERTO
RICO AND THE SAN JUAN METRO AREA TO START LATE ON WEDNESDAY AND
PERSIST THROUGH THE DAY ON THURSDAY. GFS OFFERS THE WORST CASE
SCENARIO...WITH RAINFALL MAXIMA PEAKING AROUND 10-15MM...WHILE THE
ECMWF ONLY SHOWS TRACE AMOUNTS. CONSIDERING FAVORABLE JET DYNAMICS
WE ARE LEANING TOWARDS THE WETTER GFS SOLUTION. FURTHERMORE...THE
WESTERN INTERIOR PORTIONS OF PUERTO RICO MIGHT ALSO EXPERIENCE A
FEW SHOWERS/CBS DURING THE AFTERNOON HOURS AS ENHANCE BY SEA
BREEZE CONVERGENCE/DIURNAL HEATING...BUT THIS WILL BE HIGHLY
DEPENDENT ON HOW DENSE UPPER CLOUD SHIELD REMAINS DURING THE DAY.

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







000
FXCA20 KWBC 251153
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
653 AM EST TUE NOV 25 2014

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. TUTT PATTERN
TO THE EAST OF THE ISLANDS CONTINUES TO STRENGTHEN AS A HIGH
AMPLITUDE RIDGE CONTINUES TO HOLD TO THE WEST. THE RIDGE ENVELOPS
MOST OF THE CARIBBEAN BASIN AND THE WESTERN ATLANTIC. AT LOW
LEVELS...BROAD RIDGE OVER THE CENTRAL TO WESTERN NORTH ATLANTIC
FAVORS A BRISK EASTERLY FLOW ACROSS THE CARIBBEAN BASIN...WITH
TRADE WIND SHOWERS PESTERING THE FORECAST AREA.

UNDER PRESSURE FROM A POLAR TROUGH OVER THE USA...MID/UPPER LEVEL
RIDGE IS TO GRADUALLY FLATTEN THROUGH THURSDAY MORNING. AS THE
RIDGE EVOLVES...TUTT IS TO MEANDER WEST INTO THE EASTERN
CARIBBEAN...WITH A SUBTROPICAL JET MAXIMA ALONG THE WESTERN
FRINGES TO MOVE JUST NORTH OF THE FORECAST AREA LATER ON
WEDNESDAY/EARLY THURSDAY MORNING. DIVERGENCE ON ITS LEFT EXIT
REGION IS LIKELY TO ENHANCE CONVECTIVE DEVELOPMENT ACROSS PUERTO
RICO AND THE NORTHERN VI...WITH GFS SHOWING A WEAKER TRADE WINDS
CAP ACROSS THE FORECAST AREA DURING THE DAY ON THURSDAY. OTHER
ENHANCEMENT IS POSSIBLE AS SHORT WAVE VORTICES REVOLVE AROUND THE
MEANDERING MID LEVEL LOW. EARLY ON FRIDAY THE TUTT IS TO FILL
WHILE MERGING INTO POLAR TROUGH TO THE NORTH.

AT LOW LEVELS...TUTT ALOFT IS TO SUSTAIN AN INDUCED PERTURBATION
IN THE EASTERLY TRADES. THIS MOVES ACROSS THE LEEWARD ISLANDS
EARLY ON THURSDAY... AND THROUGH FRIDAY MORNING IT MOVES ACROSS
THE VIRGIN ISLES TO EASTERN PUERTO RICO...WHERE IT IS FORECAST TO
GRADUALLY FILL/WEAKEN. IN THIS PATTERN...WE EXPECT AN INCREASE IN
TRADE WIND SHOWERS ACTIVITY ACROSS THE VIRGIN ISLES-EASTERN PUERTO
RICO AND THE SAN JUAN METRO AREA TO START LATE ON WEDNESDAY AND
PERSIST THROUGH THE DAY ON THURSDAY. GFS OFFERS THE WORST CASE
SCENARIO...WITH RAINFALL MAXIMA PEAKING AROUND 10-15MM...WHILE THE
ECMWF ONLY SHOWS TRACE AMOUNTS. CONSIDERING FAVORABLE JET DYNAMICS
WE ARE LEANING TOWARDS THE WETTER GFS SOLUTION. FURTHERMORE...THE
WESTERN INTERIOR PORTIONS OF PUERTO RICO MIGHT ALSO EXPERIENCE A
FEW SHOWERS/CBS DURING THE AFTERNOON HOURS AS ENHANCE BY SEA
BREEZE CONVERGENCE/DIURNAL HEATING...BUT THIS WILL BE HIGHLY
DEPENDENT ON HOW DENSE UPPER CLOUD SHIELD REMAINS DURING THE DAY.

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






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