Prognostic Meteorological Discussion
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FXCA20 KWBC 222017
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
316 PM EST WED FEB 22 2017

TROPICAL DISCUSSION FROM FEB 22/12 UTC: STRONG POLAR TROUGH IN THE
PLAINS OF THE USA IS UNDULATING A SURFACE COLD FRONT. BY WEDNESDAY
EVENING THE FRONT WILL EXTEND ACROSS CENTRAL CUBA-CAYMAN ISLANDS
WITH TAIL INTO EXTREME NORTHERN HONDURAS AND EASTERN GUATEMALA.
EXPECTING ACTIVITY TO FOCUS ALONG THE NORTHERN COAST OF
HONDURAS...WHERE FRONTAL CONVERGENCE AND OROGRAPHIC LIFT WILL LEAD
TO MAXIMA OF 15-25MM/DAY. DURING THIS PERIOD...FRONTAL CONVECTION
WILL PRODUCE MAXIMA OF 15-20MM/DAY IN CUBA...WHERE EXPECTING
THUNDERSTORM DEVELOPMENT. THE LARGEST MOISTURE CONVERGENCE IS
EXPECTED IN THE BAHAMAS...WHERE RAINFALL TOTALS WILL BE IN THE 15
- 20MM/DAY RANGE AND MAXIMA OF 25-50MM. BY THURSDAY EVENING...THE
FRONT WILL EXTEND ACROSS THE SOUTHEASTERN BAHAMAS...SOUTHEASTERN
CUBA...CENTRAL JAMAICA...WILL TAIL STALLED OVER THE GULF OF
HONDURAS. LARGEST RAINFALL AMOUNTS ARE TO CONCENTRATE IN THE
CENTRAL AND SOUTHEASTERN BAHAMAS WHERE EXPECTING 10-15MM/DAY AND
MAXIMA OF 20-40MM. IN THE NORTHWESTERN BAHAMAS EXPECTING MAXIMA OF
15-20MM. IN SOUTHEASTERN CUBA...SOUTH OF THE SIERRA
MAESTRA...EXPECTING ISOLATED MAXIMA OF 20-40MM/DAY UNDER
OROGRAPHIC FORCING. IN JAMAICA EXPECTING MAXIMA OF 15MM...AND
15-20MM/DAY IN AREAS SOUTHERN SLOPES WHERE OROGRAPHIC FORCING IS
SIGNIFICANT. BY FRIDAY EVENING AN ILL-DEFINED TAIL OF THE FRONT
WILL EXTEND INTO THE SOUTHEASTERN BAHAMAS. STRONGEST CONVECTION
WILL CONCENTRATE OVER THE SOUTHEASTERN BAHAMAS WHERE EXPECTING
05-10MM/DAY AND MAXIMA OF 15-20MM. IN SOUTHERN CUBA AND THE
SOUTHERN HAITIAN PENINSULA EXPECTING MAXIMA OF 10MM.

UNDER THE INFLUENCE OF THE AFOREMENTIONED UPPER TROUGH AND
FRONT...MODELS AGREE ON A REVERSAL OF THE TRADES IN THE PACIFIC
COAST OF NORTHERN CENTRAL AMERICA BY THURSDAY INTO THE WEEKEND.
ALTHOUGH MOISTURE IS LIMITED...EXPECTING THE DEVELOPMENT OF RAIN
SHOWERS IN PACIFIC BASINS OF GUATEMALA/EL SALVADOR/HONDURAS AND
NICARAGUA...WHERE EXPECTING AMOUNTS OF 05-10MM/DAY AND ISOLATED
MAXIMA OF 15MM WHERE SHOWERS DEVELOP. IN COSTA RICA...EXPECTING
ALSO CONVECTION EXTENDING INTO THE PACIFIC BASIN WITH
ACCUMULATIONS OF 05-10MM/DAY AND VERY ISOLATED MAXIMA OF 15-25MM
THROUGH THE CYCLE.

POTENT UPPER TROUGH IS EXITING THE DOMAIN ACROSS THE NORTHEASTERN
CARIBBEAN. ALTHOUGH THE TROUGH IS LOSING DIRECT INFLUENCE IN THE
WEATHER ACROSS THE CARIBBEAN...THE ASSOCIATED UPPER JET IS
ENHANCING ACTIVITY ACROSS THE GUIANAS. EXPECTING THE LARGEST
RAINFALL AMOUNTS ON THURSDAY AND FRIDAY IN AREAS THAT INCLUDE MOST
OF GUYANA AND EXTREME SOUTHEASTERN VENEZUELA...WHERE DIURNAL
CONVECTION WILL PRODUCE AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
30-60MM. AMOUNTS WILL DECREASE AFTER. OTHER REGION OF INTEREST IN
NORTHERN SOUTH AMERICA ARE THE LOWLANDS OF CENTRAL COLOMBIA. A
MOISTURE SURGE ASSOCIATED WITH WEAK SOUTHERLY TRADES IN NORTHERN
PERU IS ENHANCING LOW-LEVEL CONVERGENCE AND PRODUCING STRONG
CONVECTION. EXPECTING ACCUMULATIONS OF 15-20MM/DAY AND MAXIMA OF
50-100MM ON WEDNESDAY-THURSDAY...DECREASING TO MAXIMA OF 30-60MM
BY THURSDAY-FRIDAY. ANDEAN CONVECTION WILL GRADUALLY ACTIVATE IN
COLOMBIA TO PRODUCE AMOUNTS OF 05-10MM/DAY AND ISOLATED MAXIMA OF
15-20MM IN THE VALLE DEL CAUCA/CHOCO AND EJE CAFETERO THROUGH
EARLY FRIDAY...INCREASING TO 10-15MM/DAY AND MAXIMA OF 20-35MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC:
INITIAL   24     36     48     60     72     84     96    TYPE
40W      44W    49W    54W    59W    64W    68W   DISS     EW

A PERTURBATION IN THE TRADES...OF AFRICAN ORIGINS...IS INITIALIZED
AS AN EASTERLY WAVE AT 40W. THIS WILL STIMULATE ACTIVITY ACROSS
THE GUIANAS SLIGHTLY BY THE END OF THE WORK WEEK...ALTHOUGH MODELS
ARE STRUGGLING CAPTURING THE FEATURE...ITS INTENSITY....AND ITS
SIGNATURE ON MOISTURE FIELDS.

JIMENEZ...IMN (COSTA RICA)
SUBRATH-ALI...TTMS (TRINIDAD AND TOBAGO)
GALVEZ...WPC (USA)

$$





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