Prognostic Meteorological Discussion
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FXCA20 KWBC 061910
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TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
209 PM EST TUE DEC 06 2016

TROPICAL DISCUSSION FROM DEC 06/12 UTC: A MID LEVEL SHORT WAVE
TROUGH LIFTS ACROSS THE MID ATLANTIC REGION OF THE USA LATER
TODAY. THIS SETS THE STAGE FOR A DEEPER TROUGH TO AMPLIFY ACROSS
THE CENTRAL USA LATER ON WEDNESDAY/EARLY THURSDAY MORNING. THROUGH
THURSDAY EVENING THE DEEP TROUGH MOVES TO THE EASTERN USA. AT LOW
LEVELS A SURFACE FRONT WILL EXTEND ACROSS CENTRAL FLORIDA TO
TAMAULIPAS/COAHUILA MEXICO LATER TODAY. ON WEDNESDAY THE FRONT
WILL MEANDER TO THE NORTHWEST BAHAMAS WHILE TRAILING ACROSS SOUTH
FLORIDA TO THE RIO BRAVO IN NORTHEAST MEXICO. THE FRONTAL BOUNDARY
IS TO THEN REMAIN NEARLY STATIONARY...WHILE AN ARTIC FRONT SURGES
ACROSS NORTH AMERICA. THROUGH THURSDAY EVENING THE LATTER IS TO
THEN MERGE WITH/REINFORCE THE MEANDERING FRONT TO THE SOUTH. THE
BOUNDARY LAYER WINDS ACROSS THE GULF OF MEXICO WILL THEN INCREASE
TO 35KT...DRIVING THE FRONT SOUTH AND EAST ACROSS THE NORTHWEST
BAHAMAS-WESTERN CUBA TO VERACRUZ MEXICO EARLY ON FRIDAY MORNING.
LATER ON FRIDAY THE FRONT WILL CONTINUE TO THE CENTRAL BAHAMAS
WHILE TRAILING OVER CUBA-THE NORTHERN YUCATAN TO THE SOUTHERN
STATES OF MEXICO. STRONG FRONTAL NORTHERLIES OVER THE WESTERN GULF
ARE TO THEN PEAK AT 35-40KT. THE SURGING NORTHERLIES WILL THEN
FAVOR GENERATION OF A PREFRONTAL SHEAR LINE. EARLY ON FRIDAY
MORNING THE SHEAR LINE WILL EXTEND OVER THE CENTRAL
BAHAMAS-WESTERN CUBA TO THE GULF OF HONDURAS...WHILE ON FRIDAY
AFTERNOON IT IS TO STRETCH OVER THE SOUTHEAST BAHAMAS-EASTERN
CUBA-JAMAICA TO COSTA RICA/SOUTHEASTERN NICARAGUA. AS IT MEANDERS
ALONG THE RIO BRAVO/NORTHEAST MEXICO THE FRONT IS TO ONLY FAVOR
LIGHT CONVECTION WITH ACCUMULATION OF 00-05MM/DAY. BUT AS IT
SURGES ACROSS VERACRUZ ON THURSDAY THIS WILL SUSTAIN RAINFALL
AMOUNTS OF 15-20MM/DAY AND MAXIMA OF 35-70MM. OVER THE NORTHWEST
BAHAMAS EXPECTING RAINFALL AMOUNTS OF 00-05MM/DAY AND MAXIMA OF
10MM ON WEDNESDAY TO THURSDAY...WHILE ON THURSDAY TO FRIDAY
EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM.
OVER WESTERN-CENTRAL CUBA AND ACROSS THE NORTHERN YUCATAN THE
FRONT WILL FAVOR RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM ON FRIDAY.

AS THE MID/UPPER LEVEL TROUGH DEEPEN ACROSS NORTH AMERICA IT IS TO
PRESS AGAINST A BROAD CELL OF THE SUBTROPICAL RIDGE TO THE SOUTH.
EARLY IN THE CYCLE THE MID LEVEL RIDGE WILL ANCHOR ON A CLOSED
HIGH OVER THE SOUTHEAST BAHAMAS/EASTERN CUBA...WITH AXIS SPANNING
EXTENDING FROM SOUTHERN MEXICO-WESTERN ATLANTIC TO THE NORTHERN
CARIBBEAN. LATER ON THURSDAY...UNDER PRESSURE FROM DEEPENING POLAR
TROUGH...RIDGE WILL START TO FLATTEN WHILE THE CLOSED HIGH SETTLES
JUST NORTH OF THE LESSER ANTILLES. MEANWHILE...OVER THE NEXT FEW
DAYS THIS IS TO SUSTAIN A STRONG CAP INVERSION ACROSS THE NORTHERN
CARIBBEAN ISLES. THIS IS TO CONTINUE INHIBITING ORGANIZED DEEP
CONVECTION THROUGH AT LEAST THURSDAY EVENING. AT LOW LEVELS IT
REFLECTS AS A BROAD RIDGE OVER THE WESTERN ATLANTIC INTO THE
NORTHERN CARIBBEAN. THIS IS TO ALSO YIELD TO DEEPENING POLAR
TROUGH OVER THE EASTERN USA LATER IN THE WEEK. AS THE RIDGE
WEAKENS AND THE GRADIENT SLACKENS TRADES ACROSS THE BASIN WILL
DECREASE TO 05-10KT...WITH MOST INTENSE EXPECTED OVER THE SOUTHERN
CARIBBEAN/OFF THE COAST OF COLOMBIA TO PEAK AT 15-25KT. OVER THE
NEXT DAY OR SO THIS WILL FAVOR TRADE WIND SHOWERS ACROSS THE
EASTERN CARIBBEAN ISLES-PUERTO RICO...WITH ACCUMULATION OF 00-05MM
IN PASSING SHOWERS. SLIGHTLY HIGHER AMOUNTS ARE EXPECTED OVER THE
DOMINICAN REPUBLIC-JAMAICA ON THE NEXT COUPLE OF DAYS.

SOUTH OF THE SUBTROPICAL RIDGE...OVER THE EASTERN
CARIBBEAN...UPPER LEVEL ANALYSIS SHOWS A SHORT WAVE TROUGH
MEANDERING OFF THE COAST OF VENEZUELA. OVER THE NEXT FEW DAYS THE
UPPER LEVEL TROUGH IS TO ANCHOR ON A MEANDERING LOW JUST NORTH OF
ARUBA/ CURACAO. AS IT MEANDERS OVER THE EASTERN CARIBBEAN THIS
WILL ENHANCE CONVECTIVE DEVELOPMENT ALONG THE COAST OF VENEZUELA
AND THE ABC ISLES...WHERE WE EXPECT RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15MM. OVER NORTHWEST VENEZUELA EXPECTING
ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15-25MM OVER THE NEXT
COUPLE OF DAYS. OTHER CONVECTION TO THE SOUTH IS EXPECTED ACROSS
AMAZONIA IN SOUTHERN VENEZUELA...WHERE DIURNAL CONVECTION IS TO
SUSTAIN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM. ON
THE WESTERN PLAINS/ANDEAN REGION OF COLOMBIA EXPECTING RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-30MM IN ISOLATED TO
SCATTERED CONVECTION. THROUGH THURSDAY THIS WILL INCREASE TO
10-15MM/DAY AND MAXIMA OF 20-40MM. ACROSS PANAMA/COSTA RICA EXPECT
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM AS THE
EASTERN PACIFIC ITCZ MEANDERS OVER THE ISTHMUS.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC:

INITIAL   24     36     48     60     72     84     96    TYPE
51W      52W    55W    58W    61W    63W    67W    71W     EW

AN EASTERLY WAVE IS INITIALIZED ALONG 51W. THIS IS TO SLOWLY PULL
ACROSS FRENCH GUYANA TO SURINAME THROUGH WEDNESDAY
MORNING...MEANWHILE FAVORING RAINFALL AMOUNTS OF 00-05MM/DAY AND
MAXIMA OF 10MM. LATER ON WEDNESDAY/EARLY THURSDAY IT IS TO PULL
ACROSS GUYANA TO EASTERN VENEZUELA/WINDWARD ISLES...TO FAVOR
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM. ON THURSDAY
THIS WILL INCREASE TO 10-15MM/DAY AND MAXIMA OF 20-40MM WHILE
BUILDING WEST ACROSS MARGARITA ISLAND/NORTHEAST COAST OF
VENEZUELA. ON THE FRENCH/LEEWARD ISLES THIS IS TO THEN FAVOR
RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM. OVER
CENTRAL VENEZUELA THIS IS TO THEN FAVOR RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-20MM...WITH MOST INTENSE OVER
AMAZONIA TO THE SOUTH. CONVECTION SPREADS WEST ACROSS THE ABC
ISLES EARLY ON FRIDAY MORNING. ALONG THE NORTH COAST INTO THE ABC
ISLES EXPECTING RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF
20-40MM. OVER PUERTO RICO AND THE DOMINICAN REPUBLIC THIS IS TO
THEN RESULT IN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM.

JIMENEZ...IMN (COSTA RICA)
MIRANDA...INAMEH (VENEZUELA)
DAVISON/GALVEZ...WPC (USA)

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