Prognostic Meteorological Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4
000
FXCA20 KWBC 211056
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
655 AM EDT TUE OCT 21 2014

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. A TUTT
EXTENDS SOUTH ACROSS THE CENTRAL CARIBBEAN...WITH AXIS FROM HAITI
TO JUST NORTH OF PANAMA. A BUILDING RIDGE TO THE WEST CONTINUES TO
SLOWLY DISPLACE THIS AXIS TO THE EAST. TROUGH IS NOW FORECAST TO
MOVE ACROSS PUERTO RICO TO THE VIRGIN ISLES THROUGH THE DAY
TODAY...AND THROUGH THURSDAY MORNING IT IS TO SETTLE ACROSS THE
FRENCH ISLES TO NORTHERN VENEZUELA WHILE THE RIDGE IS TO ENVELOP
MOST OF THE BASIN. BUILDING RIDGE IS TO THEN FAVOR A SUBSIDENCE
INVERSION AND GRADUAL EROSION OF AVAILABLE MOISTURE.
MEANWHILE...AS THE TROUGH ALOFT MOVES ACROSS PUERTO RICO DURING
THE DAY...IT IS TO ENHANCE DIURNAL CONVECTION... WITH GLOBAL
MODELS ONLY SHOWING LIGHT TO MODERATE RAINFALL AMOUNTS. THE HIGHER
RESOLUTION WRF...NMM AND ARW VERSIONS OF THE MODEL...SHOW MOST
ACTIVE CLUSTERING ACROSS WESTERN INTERIOR PORTIONS OF PUERTO RICO
DURING THE AFTERNOON HOURS. THESE SHOW LOCALIZED MAXIMA OF 1.5-2.0
INCHES...AND THIS SEEMS REASONABLE CONSIDERING EVOLVING
MESO-SYNOPTIC PATTERN.

NEXT FEATURE OF INTEREST IS A TROPICAL WAVE ALONG THE ATLANTIC
ITCZ WITH AXIS NORTH ALONG 53W EARLY THIS MORNING. THIS IS
INTERACTING WITH ANOTHER TUTT EAST OF THE ISLANDS IN SUPPORT OF
ORGANIZED DEEP CONVECTION. THE WAVE ENTERS THE WINDWARD ISLANDS
LATER ON THURSDAY...AND THEN ALONG 66W BY FIRST LIGHT ON FRIDAY.
ALTHOUGH WELL ORGANIZED...AS IT ENTERS THE EASTERN CARIBBEAN THE
WAVE IS GOING TO FIGHT THE BUILDING UPPER LEVEL RIDGE AND
GROWINGLY HOSTILE ENVIRONMENTAL CONDITIONS. AS A RESULT...MOST
ACTIVE CONVECTION IS TO CONFINE TO THE SOUTHEAST CARIBBEAN.
CONVECTION...IF ANY...WOULD LIKELY CONFINE TO WESTERN INTERIOR
PORTIONS OF PUERTO RICO.

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

$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.