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
 
(Caution: Version displayed is not the latest version. - Issued 1819Z Apr 21, 2014)
 
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
219 PM EDT MON APR 21 2014

DISCUSSION FROM APRIL 21/00UTC: ACROSS MEXICO...SEASONAL
CONVECTION IS ACTIVATING PRIMARILY ACROSS THE SIERRA MADRE
ORIENTAL. MOISTURE AVAILABILITY IS LARGER. FURTHERMORE...EXPECTING
SOME AID BY UPPER TROUGH CURRENTLY POSITIONED ACROSS THE PLAINS OF
THE UNITED STATES INTO CHIHUAHUA. THIS WILL SUSTAIN DIURNAL
SHOWERS AND THUNDERSTORMS EXTENDING ACROSS MOST OF THE SIERRA
MADRE ORIENTAL SOUTH INTO OAXACA/EASTERN GUERRERO. ON MONDAY INTO
EARLY TUESDAY EXPECTING ACCUMULATIONS OF 00-05MM/DAY AND MAXIMA OF
10MM ACROSS TAMAULIPAS/COAHUILA. FURTHER SOUTH EXPECTING
05-10MM/DAY AND MAXIMA OF 15MM. ON TUESDAY INTO EARLY WEDNESDAY
EXPECTING AN INCREASE IN CENTRAL/SOUTHERN MEXICO TO 10-15MM/DAY
AND MAXIMA OF 20-30MM. EXPECTING SIMILAR AMOUNTS ON WEDNESDAY INTO
EARLY THURSDAY. SIMILARLY...DIURNAL CONVECTION ACROSS GUATEMALA
AND PARTS OF WESTERN HONDURAS/NORTHERN EL SALVADOR WILL INCREASE
INTO WEDNESDAY/THURSDAY TO PRODUCE MAXIMA OF 15-25MM/DAY.

STRONG UPPER TROUGH OFF THE COAST OF NORTH CAROLINA IS EXITING
INTO THE OPEN ATLANTIC. ASSOCIATED SURFACE FRONT IS THUS FORECAST
TO STALL AND WEAKEN ACROSS THE EXTREME SOUTHEASTERN BAHAMAS INTO
SOUTHEASTERN CUBA/NORTHERN HISPANIOLA. ALTHOUGH THE FRONT WILL NOT
PROGRESS FURTHER SOUTH OF ITS POSITION AFTER MONDAY...A REGION OF
MODERATE CONVECTIVE INSTABILITY WILL SUSTAIN A WET PATTERN ACROSS
THE REGION. A WEAK SHEAR LINE IS ALSO PRESENT AND WILL MODULATE
ACTIVITY ACROSS NORTHERN HONDURAS/SOUTHERN BELIZE TODAY...AND
JAMAICA THROUGH THE CYCLE. MONDAY-EARLY TUESDAY ACCUMULATIONS WILL
PEAK AT 05-10MM/DAY AND MAXIMA OF 15-20MM ACROSS
HISPANIOLA/SOUTHEASTERN BAHAMAS IN ASSOCIATION WITH PRE-FRONTAL
TROUGH. ON TUESDAY INTO EARLY WEDNESDAY EXPECTING A DECREASE TO
PRODUCE MAXIMA OF 15MM. A LOCAL INCREASE IS EXPECTED ACROSS
HISPANIOLA ON DAY 03 WHILE SHEAR LINE CONTINUES. THIS WILL LEAD TO
MAXIMA OF 20-30MM.

ACROSS THE EASTERN CARIBBEAN...QUIET PATTERN IS IN PLACE. THE BASE
OF AN UPPER TROUGH LOCATED ACROSS THE CENTRAL ATLANTIC IS
INTERACTING WITH A REGION OF TRADE WIND CONVERGENCE ACROSS THE
FRENCH ANTILLES. THIS WILL LEAD TO NUMEROUS SHOWERS TODAY AND
PRODUCE ACCUMULATIONS OF 05-10MM/DAY AND MAXIMA OF 15-20MM. DURING
TUESDAY INTO EARLY WEDNESDAY...WEAK TRADE WIND SURGE WILL SUSTAIN
MOST ACTIVE CONVECTION ACROSS THE LEEWARD ISLANDS INTO THE VIRGIN
ISLANDS AND EASTERN PUERTO RICO. EXPECTING AMOUNTS OF 05-10MM/DAY
AND MAXIMA OF 15MM. WEDNESDAY INTO EARLY THURSDAY EXPECTING A
DECREASE IN ACCUMULATIONS WITH LOCALIZED MAXIMA OF 15MM STILL
EXPECTED ACROSS PUERTO RICO.

ACROSS NORTHERN SOUTH AMERICA...VENTILATION HAS IMPROVED IN THE
PERIPHERY OF SUBEQUATORIAL RIDGE. AT LOW-LEVELS...A WEAK
PERTURBATION IN THE TRADES IS MOVING ACROSS THE GULF OF PANAMA.
THIS SYSTEM WILL MODULATE ACTIVITY ACROSS COSTA RICA AND PANAMA AS
WELL...LEADING TO MAXIMA OF 20-40MM ESPECIALLY ON MONDAY INTO
TUESDAY. ACROSS COLOMBIA...CONVECTIVE INSTABILITY AND VENTILATION
PEAK. THIS...IN COMBINATION WITH ARRIVING UPPER DIVERGENT PHASE OF
THE MJO...WILL LEAD TO ACTIVE DIURNAL CONVECTION THROUGH THE
CYCLE. EXPECTING ACCUMULATIONS OF 15-20MM/DAY WITH MAXIMA OF
25-50MM TODAY INTO TUESDAY...WITH MAXIMA INCREASING TO 30-60MM/DAY
AFTERWARDS.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC
INITIAL   24    36    48    60    72    84    96   TYPE
NONE SIGNIFICANT

GALVEZ...WPC (USA)
GARCIA...SMN (MEXICO)
FIGUEROA...MARN (EL SALVADOR)