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Tropical Discussion
 
(Caution: Version displayed is not the latest version. - Issued 1824Z Apr 14, 2014)
 
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TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
224 PM EDT MON APR 14 2014

DISCUSSION FROM APRIL 14/00UTC: DEEP POLAR TROUGH IS MOVING ACROSS
THE CENTRAL USA/NORTHERN STATES OF MEXICO. THROUGH TUESDAY EVENING
THIS IS TO PULL ACROSS THE EASTERN USA...THEN SLOWS DOWN TO A
CRAWL AS IT PRESSES AGAINST A RIDGE OVER THE WESTERN ATLANTIC. THE
TROUGH MOVES TO THE WESTERN ATLANTIC THROUGH THE DAY ON
WEDNESDAY...WITH MOST OF THE ENERGY LIFTING OVER THE RIDGE TO THE
EAST. AT LOW LEVELS...THE ASSOCIATED FRONT MOVES TO THE NORTHWEST
GULF OF MEXICO/NORTHEAST STATES OF MEXICO LATER THIS AFTERNOON. BY
12UTC ON TUESDAY...AS AT 35-40KT NORTHERLY SURGE ESTABLISHES
ACROSS THE WESTERN GULF...THE FRONT IS TO EXTEND ACROSS NORTH
FLORIDA-GULF TO VERACRUZ/ OAXACA. LATER IN THE DAY IT WILL MOVE TO
CENTRAL FLORIDA-NORTHERN YUCATAN/ SOUTHERN MEXICO AS A 30-35KT
NORTHERLY SURGE PERSISTS. THROUGH WEDNESDAY MORNING THE WINDS WILL
SLACKEN...WITH FRONT TO THEN TRAIL ACROSS GRAND BAHAMA-FLORIDA
KEYS TO THE NORTHERN YUCATAN. AS THE FRONT LOSES UPPER LEVEL
SUPPORT IT IS TO REMAIN NEARLY STATIONARY THROUGH WEDNESDAY
EVENING...WITH BOUNDARY TO THEN RETROGRESS ACROSS THE FLORIDA
PENINSULA-GULF DURING THE MORNING HOURS ON THURSDAY. AS THE FRONT
SURGES ACROSS TAMAULIPAS TO VERACRUZ IT IS TO TRIGGER SCATTERED
CONVECTION WITH ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF 25-50MM.
ON THE SOUTHERN STATES OF MEXICO THE FRONTAL NORTHERLIES ARE TO
THEN FAVOR RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
30-60MM...WHILE OVER THE NORTHERN YUCATAN PENINSULA EXPECTING
ACCUMULATION OF 05-10MM/DAY AND MAXIMA OF 15-25MM. PREFRONTAL
CONVECTION OVER WESTERN CUBA AND THE NORTHWEST BAHAMAS IT IS TO
THEN FAVOR RAINFALL AMOUNTS OF 05-10MM AND MAXIMA OF 15-25MM ON
TUESDAY TO WEDNESDAY. THROUGH WEDNESDAY EVENIGN THE MAXIMA
DECREASES TO 15MM.

SURGING POLAR TROUGH OVER NORTH AMERICA IS TO PRESS AGAINST A MID
LEVEL RIDGE TO THE EAST. EARLY IN THE CYCLE THE RIDGE WILL EXTEND
TO THE NORTHWEST FROM THE WESTERN CARIBBEAN...ACROSS CUBA TO THE
WESTERN ATLANTIC. THIS IS TO REMAIN NEARLY UNCHANGED THROUGH
TUESDAY MORNING...WITH SOME EROSION ACROSS SOUTHERN
MEXICO-GULF-SOUTHEAST USA LATER DURING THE DAY AS THE POLAR TROUGH
BEGINS TO LIFT OVER THIS AXIS. EARLY IN THE CYCLE THIS IS TO
SUSTAIN A TRADE WINDS CAP ACROSS NORTHERN CENTRAL AMERICA/SOUTHERN
MEXICO-CUBA. BUT AS RIDGE BEGINS TO WEAKEN FROM THE WEST THIS IS
TO SLOWLY WEAKEN THROUGH DAY 03. WEAKENING OF THE TRADE WINDS CAP
WILL THEN ALLOW FOR DEEPER MOISTURE TO POOL ACROSS
HONDURAS-NORTHERN EL SALVADOR AND GUATEMALA. DIURNAL CONVECTION IS
TO GRADUALLY BECOME MORE ACTIVE AND BETTER ORGANIZED...AS IT IS TO
CLUSTER ACROSS THE MOUNTAINS IN SOUTHERN GUATEMALA TO SOUTHERN
HONDURAS/EL SALVADOR BORDER. ACROSS GUATEMALA EXPECTING
ACCUMULATION OF 15-20MM/DAY AND MAXIMA OF 30-60MM...WHILE OVER
SOUTHERN HONDURAS/NORTHERN EL SALVADOR EXPECT RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15MM. ALTHOUGH A SOMEWHAT HOSTILE
ENVIRONMENT FOR DEEP CONVECTION IS TO GENERALLY PERSIST OVER
NORTHERN PORTIONS OF CENTRAL AMERICA DURING THE NEXT COUPLE OF
DAYS...MORE FAVORABLE ENVIRONMENTAL CONDITIONS ARE EXPECTED TO THE
SOUTH ACROSS COSTA RICA AND PORTIONS OF PANAMA. THIS AREA WILL
REMAIN ON THE DIVERGENT SIDE OF A SHORT WAVE TROUGH OVER THE
SOUTHERN CARIBBEAN. IN THIS AREA EXPECTING RAINFALL AMOUNTS OF
05-10MM/DAY AND MAXIMA OF 15-25MM...WITH MOST INTENSE TO CLUSTER
OVER THE CONTINENTAL DIVIDE WHERE MAXIMA IS LIKELY TO EXCEED 50MM.

DOWNSTREAM FROM THE RIDGE OVER THE WESTERN ATLANTIC...A MID/UPPER
LEVEL LOW CENTERS TO THE SOUTHEAST OF BERMUDA. AS IT MEANDERS OVER
THE ATLANTIC THIS IS PHASING WITH A SHORT WAVE TROUGH STREAMING
ACROSS THE BAHAMAS. THROUGH THIS AFTERNOON THESE ARE TO COMBINE
INTO A BROAD TROUGH WITH AXIS SOUTH-SOUTHWEST TO THE NORTHEAST
CARIBBEAN ISLES. AS THE TROUGH HOLDS...A SUBTROPICAL JET MAXIMA IS
TO THEN RAPIDLY ROUND THE BASE OF THIS TROUGH... WITH DIVERGENCE
ON ITS RIGHT ENTRANCE REGION TO VENT DEEP CONVECTION ACROSS PUERTO
RICO-VIRGIN ISLES EARLY THIS CYCLE. RIDGE TO THE WEST THEN
DISPLACES THIS TROUGH TO THE EAST...WITH AXIS TO THEN SETTLE OVER
THE ISLAND CHAIN LATER ON TUESDAY THROUGH WEDNESDAY. AS IT
MEANDERS OVER THE LESSER ANTILLES THE TROUGH IS TO FOCUS SHORT
WAVE ENERGY ACROSS THE LEEWARD/FRENCH ISLES. AT LOW LEVELS...BROAD
CELL OF THE BERMUDA RIDGE DOMINATES FLOW ACROSS THE NORTH
ATLANTIC...SUSTAINING AN EASTERLY FLOW ACROSS THE LESSER ANTILLES
TO THE CARIBBEAN BASIN. AS LIGHT EASTERLY TRADES PREVAIL...SHALLOW
MOISTURE IS CLUSTERING ALONG 17N/18N AND BETWEEN THE NORTHEAST
CARIBBEAN ISLES AND 50W. ALTHOUGH MID/UPPER LEVEL PATTERN
EVOLVES...THE LOW LEVELS ARE TO REMAIN NEARLY UNCHANGED THROUGH
DAY 03...WITH MOIST INFLOW ACROSS THE LEEWARD-VIRGIN ISLES
EXPECTED TO PERSIST THROUGH DAY 03. MOST ACTIVE CONVECTION ACROSS
PUERTO RICO AND THE VIRGIN ISLES IS EXPECTED TODAY...WITH RAINFALL
AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-20MM. ACROSS THE LEEWARD
ISLES EXPECT RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15MM.

FURTHERMORE...AS THE MID LEVEL TROUGH SETTLES ACROSS THE LESSER
ANTILLES...IT IS TO THEN LEAD TO RAPID EROSION OF TRADE WINDS CAP
ACROSS THE GUIANAS. THE SUBEQUATORIAL RIDGE TO THE SOUTH...AS IT
MEANDERS ACROSS THE GUIANAS...IS TO PROVIDE THE VENTILATION ALOFT
TO RESULT IN RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM...WITH MOST INTENSE ACROSS NORTHERN GUYANA.

ACROSS COLOMBIA AND VENEZUELA...MOST ACTIVE CONVECTION IS EXPECTED
TO THE SOUTH ALONG THE NEAR EQUATORIAL TROUGH. IN THIS AREA
INITIALLY EXPECTING RAINFALL AMOUNTS OF 15-20MM/DAY AND MAXIMA OF
25-50MM AS A SOUTHERLY WIND SURGE OVER BRASIL/PERU ENHANCES
MOISTURE CONVERGENCE TO THE NORTH. THROUGH TUESDAY EVENING THIS
WILL DECREASE TO 10-15MM/DAY AND MAXIMA OF 20-35MM. OVER NORTHWEST
VENEZUELA TO NORTHERN COLOMBIA EXPECTING CONVECTION TO GRADUALLY
BECOME MORE ACTIVE AND BETTER ORGANIZED THROUGH WEDNESDAY...WHEN
DIURNAL CONVECTION IS TO RESULT IN RAINFALL AMOUNTS OF 10-15MM/DAY
AND MAXIMA OF 20-35MM.

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

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