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Atlantic Tropical Weather Discussion (Text)



000
AXNT20 KNHC 210551
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
205 AM EDT MON APR 21 2014

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL  
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF 
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE 
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE 
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0545 UTC.

...ITCZ/MONSOON TROUGH...                                     
THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST OF SENEGAL 
AND THE EXTENDS OVER THE EASTERN TROPICAL ATLANTIC ALONG 13N17W 
TO 06N23W. THE ITCZ BEGINS FROM THERE AND CONTINUES JUST S OF 
THE EQUATOR WEST OF 35W TO THE NORTHERN COAST OF BRAZIL NEAR 
01S46W. SCATTERED MODERATE CONVECTION EXISTS WITHIN 120 NM OF 
THE ITCZ WEST OF 35W.  SCATTERED MODERATE ISOLATED STRONG 
CONVECTION EXISTS SOUTH OF WEST AFRICA EAST OF 10W. 

...DISCUSSION...                                                

GULF OF MEXICO...                                               
A 1021 MB SURFACE HIGH IS ANALYZED ALONG THE FLORIDA PANHANDLE 
WITH A WEAK SURFACE PRESSURE GRADIENT ACROSS THE GULF OF MEXICO. 
CORRESPONDINGLY...SURFACE WINDS ARE GENERALLY GENTLE TO MODERATE 
BREEZE CONDITIONS OUT OF THE NORTHEAST IN THE EASTERN GULF AND 
SOUTHEAST IN THE WESTERN GULF.  NO SIGNIFICANT DEEP CONVECTION 
OR SHOWERS ARE CURRENTLY OCCURRING.  RELATIVELY THICK CIRRUS IS 
BLOWING EASTWARD ACROSS THE WEST CENTRAL GULF AS UPPER-LEVEL 
DEBRIS CLOUDINESS FROM LATE AFTERNOON AND EARLY EVENING DEEP 
CONVECTION OVER CENTRAL MEXICO.  OVER THE NEXT COUPLE OF 
DAYS...THE WINDS WILL DROP OFF EVEN MORE AS THE WEAK SURFACE 
HIGH DRIFTS SOUTHWESTWARD INTO THE CENTRAL GULF.  NO SIGNIFICANT 
DEEP CONVECTION OR SHOWERS ARE EXPECTED FOR THE NEXT 
DAY...THOUGH LATE TUESDAY SOME CONVECTION COULD DEVELOP IN THE 
NORTHERN GULF OF MEXICO AHEAD OF AN ADVANCING COLD FRONT.

CARIBBEAN SEA... 
THE TAIL END OF A COLD FRONT EXTENDS ACROSS THE 
CENTRAL BAHAMAS TO EASTERN CUBA.  SCATTERED MODERATE ISOLATED 
STRONG CONVECTION EXISTED OVER EASTERN CUBA AND THE EASTERN 
BAHAMAS EARLIER...THOUGH THIS IS CURRENTLY DISSIPATING.  A 
MODERATE NORTH-SOUTH SURFACE PRESSURE GRADIENT EXISTS ACROSS THE 
CARIBBEAN AND THE EASTERLY TRADEWINDS ARE GENTLE TO FRESH BREEZE 
CONDITIONS...WITH THE USUAL EXCEPTION OF STRONGER NE WINDS OF 25 
KT NORTH OF COLOMBIA. OVER THE NEXT COUPLE OF DAYS...THE SURFACE 
PRESSURE GRADIENT WEAKENS AND WINDS FURTHER SLACKEN. ENHANCED 
TOTAL PRECIPITABLE WATER IS OBSERVED WITH THE TPW IMAGERY ACROSS 
THE EASTERN BAHAMAS...EASTERN CUBA...AND THE NORTHWESTERN 
CARIBBEAN.  ADDITIONALLY...A WEAK MAXIMA IN MOISTURE 
ALSO...POSSIBLY AN EARLY SEASON WEAK TROPICAL WAVE...IS REACHING 
THE WINDWARD ISLANDS.  WHILE THE FRONTAL BOUNDARY SHOULD 
DISSIPATE NEAR THE BAHAMAS SHORTLY...THE RESIDUAL MOISTURE AND 
CONVERGENCE MAY CONTINUE TO AID THE DEVELOPMENT OF SCATTERED 
DEEP CONVECTION IN THE EASTERN BAHAMAS...EASTERN 
CUBA...HISPANIOLA...AND JAMAICA DURING THE NEXT COUPLE OF DAYS. 
ADDITIONALLY...THE WEAK MAXIMA IN MOISTURE IS SUGGESTED BY THE 
GFS TO MOVE NORTHWESTWARD AND MAY ENHANCE SHOWER AND WIDELY 
SCATTERED DEEP CONVECTION OVER THE LESSER ANTILLES AND PUERTO 
RICO. HOWEVER...SUCH CONVECTIVE ACTIVITY IS NOT EXPECTED TO BE 
WIDESPREAD...AS SUBSIDENT UPPER-LEVEL WESTERLY FLOW COVERS THE 
CARIBBEAN AS IS TYPICAL FOR THIS TIME OF YEAR.

...HISPANIOLA...                                                
THE DEEP CONVECTION THAT OCCURRED OVER THE HIGH TERRAIN OF HAITI 
AND DOMINICAN REPUBLIC EARLIER TODAY HAS DIMINISHED.  ENHANCED 
TOTAL PRECIPITABLE WATER IS OBSERVED WITH THE TPW IMAGERY ACROSS 
THE EASTERN BAHAMAS...EASTERN CUBA...AND THE NORTHWESTERN 
CARIBBEAN. WHILE THE FRONTAL BOUNDARY SHOULD DISSIPATE NEAR THE 
BAHAMAS SHORTLY...THE RESIDUAL MOISTURE AND CONVERGENCE MAY 
CONTINUE TO AID THE DEVELOPMENT OF SCATTERED DEEP CONVECTION IN 
HISPANIOLA DURING THE NEXT COUPLE OF DAYS. HOWEVER...SUCH 
CONVECTIVE ACTIVITY IS NOT EXPECTED TO BE WIDESPREAD...AS 
SUBSIDENT UPPER-LEVEL WESTERLY FLOW COVERS THE CARIBBEAN AS IS 
TYPICAL FOR THIS TIME OF YEAR.

ATLANTIC OCEAN... 
A 1009 MB SURFACE LOW IS SOUTH OF NORTH 
CAROLINA NEAR 31N75W WITH A COLD FRONT EXTENDING SOUTHWARD TO 
EASTERN CUBA AND A SECONDARY TROUGH EXTENDING SOUTHWESTWARD TO 
THE NORTHWESTERN BAHAMAS.  A PRE-FRONTAL SQUALL LINE IS ABOUT 
100 NM AHEAD OF THE FRONT NORTH OF 25N.  SURFACE WINDS REACH UP 
TO 30 KT IN THE NORTHERLY FLOW JUST OFFSHORE OF NORTHEASTERN 
FLORIDA.  ALL OF THIS IS SUPPORTED BY A VIGOROUS UPPER-LEVEL 
CUTOFF LOW AT ABOUT THE SAME LOCATION AS THE SURFACE LOW.  THE 
UPPER-LEVEL LOW SHOULD LIFT OUT AND BECOME AN OPEN TROUGH AS IT 
QUICKLY MOVES NORTHEASTWARD.  WHILE THE BAROCLINICITY OF THE 
COLD FRONT WEAKENS SOME...LARGE AMOUNTS OF MOISTURE AND UPPER-
LEVEL FORCING SHOULD CONTINUE TO PROVIDE THE POTENTIAL FOR AT 
LEAST SCATTERED DEEP CONVECTION AHEAD AND ALONG THE FRONT FOR 
THE NEXT COUPLE OF DAYS.  WHILE THE NORTHERLY FLOW BEHIND THE 
FRONT SHOULD GRADUALLY WEAKEN...THE SOUTHWESTERLY WINDS AHEAD OF 
THE FRONT SHOULD STRENGTHEN UP TO STRONG BREEZE OR NEAR GALE 
CONDITIONS FOR THE NEXT TWO DAYS.   FARTHER TO THE EAST...A 
ANOTHER COLD FRONT MAY JUST REACH AROUND 30N EAST OF 40W LATE ON 
MONDAY...THOUGH THE POTENTIAL FOR DEEP CONVECTION WITH THIS 
APPEARS MINIMAL AND WINDS REMAIN LIGHT ACROSS THE FRONT.  
ELSEWHERE...THE REMAINDER OF THE ATLANTIC IS DOMINATED BY A 
SURFACE RIDGE ANCHORED BY A 1025 MB HIGH NEAR 30N45W WHICH IS 
EXPECTED TO DRIFT EASTWARD OVER THE NEXT TWO DAY.  FAIR WEATHER 
IS OVER THE CENTRAL AND EASTERN ATLANTIC BEING SUPPORTED BY DRY 
AIR SUBSIDENCE FROM THE MIDDLE LEVELS. 

FOR ADDITIONAL INFORMATION PLEASE VISIT 
WWW.HURRICANES.GOV/MARINE

$$
LANDSEA


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Page last modified: Monday, 21-Apr-2014 05:51:53 UTC