Atlantic Tropical Weather Discussion

000
AXNT20 KNHC 080004
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
705 PM EST FRI MAR 076 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...SPECIAL FEATURE...                                           
GALE CONDITIONS ARE FORECAST TO BEGIN LATER TONIGHT N OF 26N 
WITHIN 180 NM E OF FRONT THAT WILL EXTEND FROM 31N69W TO 22N78W. 
PLEASE SEE THE HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS 
MIAHSFAT2/ FZNT01 KNHC OR THE OFFSHORE FORECAST UNDER AWIPS/WMO 
HEADERS MIAOFFNT4/FZNT24 KNHC FOR MORE DETAILS. 

...ITCZ/MONSOON TROUGH...                                     
THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC 
NEAR 10N14W AND CONTINUES ALONG 3N20W TO 1N30W WHERE THE ITCZ 
BEGINS AND CONTINUES S OF THE EQUATOR NEAR 41W. A CLUSTER OF 
SCATTERED MODERATE TO STRONG CONVECTION WAS NOTED FROM 2N TO 5N 
BETWEEN 10W-14W. 

...DISCUSSION... 

GULF OF MEXICO...                                               
UPPER LEVEL TROUGH MOVING ACROSS THE EASTERN SEABOARD APPEARS TO 
BE SHEARING OUT TO THE NE AS IT RIDES OVER A LARGE EXPANSIVE 
ANTICYCLONE AND RIDGE OVER THE CARIBBEAN AND SW N ATLC. AN UPPER 
LEVEL CYCLONE NEAR CAPE HATTERAS NC IS TURNING TO THE NE AND 
ELONGATING WITH TIME. THE TROUGH EXTENDED SOUTHWARD ACROSS 
FLORIDA AND WAS BEING SUPPLANTED BY A SHORTWAVE RIDGE OVER THE 
GULF W OF 90W. STRONG SUBSIDENCE OVER THE GULF WAS GRADUALLY 
BEING OVERTAKEN BY UPPER LEVEL MOISTURE N OF 25N W OF 88W. AT 
THE SURFACE...1021 MB HIGH PRESSURE OVER MISSISSIPPI RIDGED INTO 
THE GULF WITH NW WINDS E OF 90W AND RETURN SE FLOW DEVELOPING W 
OF 90W. COLD AIR STRATOCUMULUS CLOUDS COVER THE GULF N OF 24N 
AND E OF 91W AND EXTEND OVER FLORIDA. OVERCAST STRATUS CLOUDS 
WITH AREAS OF DENSE FOG AND DRIZZLE WERE NOTED OVER THE GULF W 
OF 96W AND WERE BANKED UP ALONG THE SIERRA MADRE. SURFACE RIDGE 
WILL SLIDE E ON SAT AND ALLOW RETURN FLOW TO EXPAND OVER THE 
GULF W OF 90W. A COLD FRONT IS EXPECTED TO MOVE INTO THE W GULF 
EARLY SUN WITH SCATTERED SHOWERS AND THUNDERSTORMS IN ITS WAKE. 

CARIBBEAN SEA...                                                 
AN EXPANSIVE ANTICYCLONE OVER THE CARIBBEAN HAS SHIFTED E WITH A 
BROAD AREA OF S TO SW WINDS ALOFT OVER THE CARIBBEAN W OF 65W. 
THIS FLOW WAS ADVECTING MAINLY HIGH LEVEL MOISTURE W OF 70W.  
THE SW N ATLC COLD FRONT EXTENDS ACROSS CUBA AND THE ISLE OF 
YOUTH THEN BECOMES STATIONARY FROM 20N84W TO THE WESTERN GULF OF 
HONDURAS. SCATTERED SHOWER ACTIVITY ASSOCIATED WITH THE FRONT 
WAS DISSIPATING WITH TIME. LOW LEVEL CONVERGENCE BETWEEN 
EASTERLY TRADE WINDS AND SW FLOW AHEAD OF THE FRONT WAS 
RESULTING IN A PATCH OF BROKEN TO OVERCAST LOW CLOUDS WITH  
ISOLATED LOW TOPPED SHOWERS OVER JAMAICA...EASTERN CUBA AND THE 
WINDWARD PASSAGE. ADDITIONAL ACTIVITY WAS NOTED N OF A LINE FROM 
THE WINDWARD ISLANDS NEAR SAINT LUCIA TO S OF THE MONA PASSAGE 
NEAR 17N68W. FRONT WILL STALL TONIGHT INTO THROUGH SAT THEN 
WEAKEN TO A TROUGH AND EXTEND FROM E CUBA TO 20N88W SUN. FRESH 
TO STRONG TRADE WINDS WILL PREVAIL ALONG THE COAST OF COLOMBIA 
WHILE MODERATE TO FRESH TRADE WINDS WILL BE FOUND OVER THE 
REMAINDER OF THE AREA THROUGH SUN.

HISPANIOLA...                                               
ISOLATED LOW LEVEL SHOWERS ARE DEVELOPING INLAND AND WITHIN 60 
NM ALONG THE S COAST OF HISPANIOLA BETWEEN 70W-74W LEAVING THE 
REMAINDER OF THE ISLAND WITH FAIR CONDITIONS. THE UPPER RIDGE 
WILL REMAIN IN PLACE THROUGH MON WHILE AN UPPER TROUGH OVER THE 
W ATLC CONTINUES TO MOVE E INTO THE CENTRAL ATLC SAT COVERING 
THE AREA N OF THE ISLAND THROUGH MON. A W ATLC COLD FRONT WILL 
MOVE TO OVER E CUBA EARLY SAT WHERE IT WILL BEGIN TO WEAKEN AS 
IT MOVES TO THE CENTRAL ATLC ALIGNING ALONG E/W ACROSS THE ISLAND 
SAT NIGHT INTO SUN. THE LOW LEVEL MOISTURE ASSOCIATED WITH THIS 
FRONT WILL MOVE OVER THE ISLAND OVER THE WEEKEND WITH INCREASING 
SHOWERS ACROSS THE ENTIRE ISLAND.

ATLANTIC OCEAN...                                               
AN UPPER TROUGH ALONG THE EASTERN SEABOARD EXTENDING INTO THE SW 
N ATLC W OF 72W IS BEGINNING TO LIFT NE OVER THE AMPLIFIED RIDGE 
WHICH EXTENDS FROM THE CARIBBEAN. THE RIDGE AXIS EXTENDS FROM 
THE LEEWARD ISLANDS THROUGH 32N55W. THE DOWNSTREAM BROAD TROUGH 
EXTENDS FRO0M AN UPPER LEVEL CYCLONE NEAR 30N19W SW THROUGH 
17N40W TO A BASE NEAR 07N50W. VERY STRONG SUBSIDENCE WAS NOTED
WITHIN 300 NM SE OF THE TROUGH AXIS...WITH GENERAL SUBSIDENCE 
NOTED ELSEWHERE OVER THE TROPICAL ATLC W OF 30W FROM 08N TO 23N. 
AT THE SURFACE...A COLD FRONT ENTERS THE DISCUSSION AREA 
THROUGH 32N73W TO BIMINI ISLAND INTO THE STRAITS OF FLORIDA. THE 
FRONT WAS CLOSING IN ON A PRE-FRONTAL TROUGH WHICH WAS PARALLEL 
TO THE FRONT 45-60 NM TO THE EAST AND S OF 30N. SCATTERED 
SHOWERS AND THUNDERSTORMS WERE NOTED WITHIN 90 NM E OF THE 
TROUGH N OF 27N. A SURFACE RIDGE DOMINATES THE REMAINDER OF THE 
ATLC ANCHORED BY A 1022 MB HIGH NEAR 27N49W. COLD FRONT WILL 
CONTINUE TO MOVE RE AND EXTEND FROM NEAR 31N67W TO E CUBA EARLY 
SAT THEN BEGIN TO WEAKEN AS IT MOVES INTO THE CENTRAL ATLC SAT 
NIGHT INTO SUN. A SURFACE RIDGE WILL BUILD ACROSS THE W ATLC IN 
THE WAKE OF THE FRONT THROUGH MON. 

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

$$ 
COBB