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114
FXCA20 KWBC 221915
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
215 PM EST MON DEC 22 2014

DISCUSSION FROM DECEMBER 22/00UTC: A HIGHLY AMPLIFIED SINUSOIDAL
WAVE PATTERN IS INITIALIZED ACROSS THE DOMAIN...WITH A MID/UPPER
LEVEL TROUGH EXTENDING ACROSS THE CENTRAL USA-MEXICO WHILE A RIDGE
DOMINATES THE CARIBBEAN BASIN/WESTERN ATLANTIC. THE MID LEVEL
TROUGH REACHES MAXIMUM AMPLITUDE THROUGH TUESDAY EVENING...THEN
STARTS TO LIFT OVER THE RIDGE TO THE EAST AS A 130-150KT JET
MAXIMA ROUNDS THE BASE OF THE LONG WAVE TROUGH. MEANWHILE...AS THE
TROUGH MEANDERS OVER MEXICO...IT IS TO ENHANCE MOISTURE TRANSPORT
ACROSS THE SOUTHWEST STATES OF COLIMA-NAYARIT...WHERE WE EXPECT
RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF 10MM THROUGH TUESDAY
MORNING AND 05-10MM/DAY WITH MAXIMA OF 15MM ON TUESDAY TO
WEDNESDAY.

AT LOW LEVELS...A MEANDERING FRONT IS TO EXTEND ACROSS THE
SOUTHERN USA THROUGH MIDDAY ON TUESDAY. BUT AS THE TROUGH ALOFT
DEEPENS...A FRONTAL LOW IS TO FORM OVER LOUISIANA. THIS IS TO
RAPIDLY DEEPEN...SUSTAINING A 30-35KT NORTHERLY WIND SURGE ACROSS
THE WESTERN GULF. THIS...IN-TURN...IS TO DRIVE THE FRONT SOUTH
ACROSS THE GULF TO SOUTHERN TAMAULIPAS/NORTHERN VERACRUZ LATER ON
TUESDAY. THROUGH WEDNESDAY MORNING THE FRONTAL NORTHERLIES
INCREASE TO 35-40KT...WITH THE FRONT RACING ACROSS SOUTHERN
VERACRUZ TO OAXACA-CHIAPAS IN SOUTHERN MEXICO. THROUGH WEDNESDAY
EVENING THE FRONT MOVES ACROSS THE YUCATAN PENINSULA...AND EARLY
ON THURSDAY IT IS TO EXTEND ACROSS SOUTH FLORIDA-WESTERN CUBA TO
THE GULF OF HONDURAS/SOUTHERN BELIZE AS THE NORTHERLIES PEAK AT
25-30 KT. THROUGH THURSDAY EVENING THE FRONT MEANDERS TO THE
NORTHWEST BAHAMAS WHILE TRAILING ACROSS WESTERN CUBA TO THE GULF
OF HONDURAS. THE PROGRESSIVE FRONT IS TO TRIGGER SCATTERED
CONVECTION ACROSS VERACRUZ-PUEBLA/CENTRAL MEXICO EARLY ON
WEDNESDAY WITH RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM. STRONG NORTHERLIES ARE TO TRIGGER MODERATE TO HEAVY
CONVECTION ACROSS CHIAPAS/TABASCO-CAMPECHE-NORTHERN
OAXACA-SOUTHERN VERACRUZ THROUGH WEDNESDAY EVENING...WITH
ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF 20-40MM/DAY. ACROSS
WESTERN CUBA IT IS TO THEN FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY
AND MAXIMA OF 25-50MM...WITH MOST INTENSE EXPECTED ACROSS YOUTH
ISLAND. OVER THE NORTHWEST BAHAMAS THIS IS TO THEN FAVOR RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM EARLY ON THURSDAY.
STRONG NORTHERLIES OVER THE NORTHWEST CARIBBEAN ARE TO THEN
ENHANCE CONVECTIVE DEVELOPMENT ACROSS NORTHWEST HONDURAS-ISLAS DE
LA BAHIA AND NORTHEAST GUATEMALA...WITH RAINFALL AMOUNTS OF
15-30MM/DAY AND MAXIMA OF 40-80MM.

MID LEVEL RIDGE OVER THE CARIBBEAN BASIN IS TO SPAN FROM CENTRAL
AMERICA TO THE NORTHERN GUIANAS INTO THE WESTERN ATLANTIC. THE 500
HPA RIDGE IS TO ANCHOR ON A CLOSED HIGH THAT IS TO MEANDER TO THE
NORTH OF THE DOMINICAN REPUBLIC OVER THE NEXT FEW DAYS. THIS IS TO
SUSTAIN A STRONG CAP INVERSION ACROSS THE NORTHERN CARIBBEAN
ISLES-LESSER ANTILLES TO NORTHERN SOUTH AMERICA...AND IT IS TO
GENERALLY FAVOR FAIR WEATHER CONDITIONS. SHALLOW CONVECTION IS TO
LIMIT TO THE OCCASIONAL CLOUD CLUSTER ROUNDING THE LOW LEVEL
SUBTROPICAL RIDGE AS IT MEANDERS OVER THE WESTERN ATLANTIC. ACROSS
THE LEEWARD ISLES-PUERTO RICO-NORTHERN HISPANIOLA THIS IS TO
RESULT IN RAINFALL AMOUNTS OF 00-05MM/DAY AND WIDELY ISOLATED
MAXIMA OF 10MM. THE LOW LEVEL RIDGE IS TO ANCHOR ON A CLOSED HIGH
TO THE SOUTH-SOUTHEAST OF BERMUDA. THIS IS TO SUSTAIN A TIGHT
GRADIENT ACROSS THE BASIN WITH WINDS OF 30-35KT OVER THE SOUTHERN
CARIBBEAN WHILE TO THE NORTH EXPECTING WINDS OF 20-25KT.

SOUTH OF THIS RIDGE...THE PANAMANIAN LOW IS TO CENTER JUST WEST OF
BUENAVENTURA/CALI IN WESTERN COLOMBIA. AS IT MEANDERS TO THE WEST
THIS IS TO SUSTAIN A MOIST WESTERLY FLOW ACROSS THE CAUCA/CAUCA
VALLEY TO THE SOUTHWEST...WITH RAINFALL AMOUNTS OF 05-10MM/DAY AND
MAXIMA OF 15-20MM. OTHER CONVECTION IS TO CLUSTER ALONG THE ANDES
TO THE NORTHWEST...WITH RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA
OF 10MM.

EAST OF THE UPPER LEVEL RIDGE...OVER THE ATLANTIC...A 250 HPA
TROUGH IS TO EXTEND TO THE SOUTHWEST ALONG 20N 50W TO NORTHEAST
VENEZUELA. THIS IS TO PERSIST OVER THE NEXT THREE DAYS. A SOUTHERN
HEMISPHERE TUTT LOW CENTERS NEAR RECIFE IN NORTHEAST BRASIL. THE
TUTT TO THE NORTH AND ONE TO THE SOUTH ARE INTERACTING WITH THE
ATLANTIC ITCZ...SUSTAINING A SURGE IN CONVECTION TO THE EAST OF
50W. PREVAILING EASTERLY TRADES CARRY SOME OF THIS MOISTURE
WESTWARD ACROSS THE NORTHERN GUIANAS TO NORTHEAST
VENEZUELA/SOUTHERN WINDWARD ISLANDS. THIS WILL FEED THE DAILY HEAT
CYCLE/SEA BREEZE CONVERGENCE TO RESULT IN RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM. MOST INTENSE IS EXPECTED OVER
NORTHERN GUYANA AND THE ORINOCO DELTA REGION IN VENEZUELA.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL  24     36     48     60     72     84     96     TYPE

NONE.

JN BAPTISTE...MS (SAINT LUCIA)
NANDA...MDS (SURINAME)
DAVISON...WPC (USA)
$$






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