Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center
 
Tropical Discussion
 
(Latest Discussion - Issued 1141Z Nov 24, 2017)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
Abbreviations and acronyms used in this product


TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
641 AM EST FRI NOV 24 2017

PRELIMINARY DISCUSSION FOR PUERTO RICO FROM NOV 24/06 UTC:
FORECAST AREA REMAINS ON THE CONVERGENT SIDE OF A MID LEVEL CELL
OF THE SUBEQUATORIAL RIDGE EXTENDING OVER THE EASTERN CARIBBEAN TO
THE WESTERN ATLANTIC. AT 500 HPA THE RIDGE ANCHORS ON A CLOSED
HIGH TO THE NORTH-NORTHEAST OF PUERTO RICO. AT LOW
LEVELS...REMNANTS OF A TUTT INDUCED PERTURBATION IN THE EASTERLY
TRADES IS PULLING ACROSS THE MONA PASSAGE EARLY THIS MORNING.
PLUME OF TROPICAL MOISTURE TRAILS THIS PERTURBATION...AS IT
EXTENDS OVER PUERTO RICO-USVI TO THE NORTHERN LEEWARD ISLANDS.
ALTHOUGH THIS FAVORS HIGH MOISTURE...WITH PWAT CONTENT OF 1.75-2.0
INCHES...THE ENVIRONMENTAL CONDITIONS REMAIN HOSTILE TO ORGANIZED
DEEP CONVECTION. AS A RESULT...ONLY EXPECTING LIGHT-MODERATE
CONVECTION TO AFFECT PUERTO RICO DURING THE DAY TODAY...WITH MOST
ACTIVE ALONG THE CORDILLERA AND POSSIBLY WESTERN INTERIOR PORTIONS
OF THE ISLAND IN MIDAFTERNOON CONVECTION.

THE MID LEVEL RIDGE PATTERN IS TO GENERALLY HOLD OVER THE NEXT FEW
DAYS. LATER ON SUNDAY...HOWEVER...RIDGE STARTS TO FLATTEN AS A
LONG WAVE TROUGH TO THE WEST STARTS TO LIFT OVER THIS AXIS.
EROSION OF THE RIDGE OVER THE WESTERN ATLANTIC CONTINUES ON
TUESDAY/WEDNESDAY...WHEN THE RIDGE IS TO THEN CONFINE TO THE
CENTRAL/WESTERN CARIBBEAN AND TO THE SOUTH OF 20N. ALTHOUGH THE
RIDGE TENDS TO WEAKEN...THE ENVIRONMENTAL CONDITIONS ARE TO REMAIN
HOSTILE TO ORGANIZED CONVECTION. AS THE PATTERN HOLDS...PLUME OF
TROPICAL MOISTURE SEEPING UNDER THE RIDGE IS TO RAPIDLY MOVE AWAY
ON SATURDAY. IN A DEEP LAYER EASTERLY FLOW...A DRYER AIR MASS THEN
ENTRAINS FROM THE EAST EARLY ON SATURDAY MORNING. THIS IS TO
PERSIST THROUGHOUT THE WEEKEND...TO GENERALLY FAVOR FAIR WEATHER
CONDITIONS ACROSS THE ENTIRE FORECAST AREA. DURING THE
WEEKEND...IN A COOL ADVECTIVE PATTERN...EARLY MORNING TRADE WIND
SHOWERS ARE TO PESTER THE VIRGIN ISLES/EASTERN PUERTO RICO FROM
TIME-TO-TIME. BUT THESE ARE TO GENERALLY FAVOR TRACE RAINFALL
AMOUNTS IN BRIEF RAIN SHOWERS. OTHER CONVECTION IS EXPECTED ACROSS
WESTERN PUERTO RICO DURING THE AFTERNOON HOURS...TO CLUSTER
BETWEEN RINCON-AGUADILLA/ISABELA...WHERE IT IS TO SUSTAIN LIGHT
RAINFALL AMOUNTS. A SLIGHT INCREASE IS POSSIBLE ON MONDAY AS A
SECONDARY MOIST PLUME ADVECTS ACROSS THE NORTHEAST CARIBBEAN. BUT
THIS WILL BE SHORT LASTING...AS A DRYER AIR MASS IT TO QUICKLY
TAKE ITS PLACE ON TUESDAY-WEDNESDAY.

DAVISON...WPC (USA)