[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 220002
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI MAR 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...THE ITCZ/THE MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC
NEAR 8N12W SW TO 4N21W. THE ITCZ AXIS EXTENDS FROM 5N21W TO
2N30W TO THE EQUATOR AT 41W THEN TO THE COAST OF SOUTH AMERICA
NEAR 2S45W. NO SIGNIFICANT CONVECTION WAS NOTED ALONG THE
AXES.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL FLOW OVER THE GULF WAS PRIMARILY ANTICYCLONIC WITH A
RIDGE AXIS ALONG 93W. SUBSIDING AIR PREVAILED OVER THE SOUTHERN
TWO-THIRDS OF THE GULF WITH MID TO UPPER LEVEL MOISTURE NOTED N
OF 27N. THIS MOISTURE WAS BEING ADVECTED BY STRONG WESTERLY
WINDS. NWP GRIDDED WINDS AT 250 MB INDICATED WINDS OF 80-90 KT
OVER THE GULF COAST. AT THE SURFACE...BROAD SURFACE RIDGING WAS
ANCHORED BY A 1022 MB HIGH NEAR CHARLESTON SOUTH CAROLINA AND A
1019 MB HIGH NEAR 27N86W. LIGHT E TO SE WINDS PREVAILED OVER THE
GULF WITH SPEEDS GENERALLY 5-10 KT...EXCEPT 10-15 KT ALONG THE
TEXAS GULF COAST. A SURFACE TROUGH WAS NOTED ALONG THE WEST
COAST OF FLORIDA EXTENDING FROM NEAR CEDAR KEY TO JUST NORTH OF
KEY WEST. FAIR SKIES WERE NOTED OVER MOST OF THE GULF WITH THE
ONLY EXCEPTION BEING AN AREA OF LOW CLOUDS WITH POSSIBLE
ISOLATED SHOWERS FROM 23N TO 29N BETWEEN 88W AND 96W. LOOKING
AHEAD...THE RIDGE IS FORECAST TO WEAKEN ON SAT IN RESPONSE TO A
COLD FRONT SLATED TO MOVE INTO THE NW GULF WATERS SUN AFTERNOON
WITH AN INCREASE IN SHOWERS AND THUNDERSTORMS OVER THE N CENTRAL
GULF AHEAD OF THE FRONT ON SUN.

CARIBBEAN...
A BROAD UPPER RIDGE COVERS THE WESTERN AND CENTRAL CARIBBEAN
WHILE A SHARP TROUGH EXTENDS SOUTHWARD ALONG 58W...JUST E OF THE
WINDWARD 1SLANDS. WATER VAPOR IMAGERY SHOWS DRY STABLE AIR AT
THE MID AND UPPER LEVELS ACROSS THE ENTIRE BASIN WHICH IS
SUPPRESSING THE DEVELOPMENT OF ANY DEEP CONVECTION. PATCHES OF
RESIDUAL SURFACE TO LOW-LEVEL MOISTURE ASSOCIATED WITH A
STATIONARY FRONT CURRENTLY OVER THE SW N ATLC LINGER OVER THE NW
CARIBBEAN AND PORTIONS OF HISPANIOLA. THIS MOISTURE IS
SUPPORTING LOW LEVEL CLOUDINESS ACROSS CENTRAL CUBA AND
HISPANIOLA WITH POSSIBLE ISOLATED SHOWERS. OTHERWISE...TRADES OF
15-20 KT ARE ACROSS THE CENTRAL AND EASTERN CARIBBEAN WITH WINDS
REACHING OF 25 KT ALONG THE COAST OF COLOMBIA. THIS WAS
CONFIRMED BY A MUCH EARLIER ASCAT PASS. EXPECT LITTLE CHANGE
OVER THE NEXT 48 HOURS.

HISPANIOLA...
LATE DAY VISIBLE SATELLITE IMAGERY SHOWED SCATTERED LOW CLOUDS
ACROSS THE ISLAND WITH ISOLATED SHOWERS/THUNDERSTORM ALONG THE N
FACING SLOPES OF THE ISLANDS ON THE BORDER OF HAITI AND THE
DOMINICAN REPUBLIC. THIS CLOUDINESS IS BEING SUPPORTED BY
LINGERING MOISTURE ASSOCIATED WITH A FORMER FRONT THAT MOVED
ACROSS CUBA. WITH AMPLE DRY AIR ALOFT AS SEEN IN THE VAPOR
IMAGERY...LOW-LEVEL MOISTURE IS FORECAST TO REMAIN AT A MINIMUM
THROUGH THE NEXT 24-48 HRS WITH THE EXCEPTION OF SHOWER ACTIVITY
THAT DEVELOPS WITH AFTERNOON HEATING.

ATLANTIC...
A FAIRLY SHARP MIDDLE TO UPPER LEVEL TROUGH EXTENDS ACROSS THE
WESTERN ATLC THROUGH 32N65W TO THE SE BAHAMAS. THIS TROUGH
SUPPORTS A COLD FRONT THAT EXTENDS FROM A 1012 MB LOW NEAR
32N61W THROUGH 25N70W TO THE SE BAHAMAS WHERE THE FRONT IS IN
THE PROCESS OF WEAKENING TO THE N COAST OF CUBA NEAR 21N76W. A
PRE-FRONTAL TROUGH EXTENDED FROM 29N62W TO 24N68W. THE COLD
FRONT IS EXPECTED TO MERGE WITH THE TROUGH OVER THE NEXT SIX
HOURS. A WARM FRONT EXTENDED FROM THE LOW EASTWARD TO 31N54W
WHERE IT BECAME STATIONARY TO 32N48W. MULTILAYERED CLOUDINESS
WITH AREAS OF RAIN AND SCATTERED EMBEDDED SHOWERS WERE NOTED
ALONG AND WITHIN 60 NM NW OF THE FRONT FROM 27N TO 31N. ISOLATED
THUNDERSTORMS WERE NOTED ALONG THE PRE-FRONTAL TROUGH.
OTHERWISE...A FAIRLY SHARP UPPER LEVEL TROUGH EXTENDED FROM A
CYCLONIC CIRCULATION NEAR 22N55W TO TRINIDAD. THIS TROUGH WAS
RIDING OVER A BROAD ANTICYCLONE OVER THE DEEP TROPICS ALONG 5N
EAST OF 50W. AT THE SURFACE...THE REMAINDER OF THE ATLC E OF 60W
IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1027 MB HIGH
JUST N OF THE AREA NEAR 33N30W. WEAKER HIGH PRES IS PRESENT W OF
65W ANCHORED BY A 1022 MB HIGH NEAR CHARLESTON SOUTH CAROLINA.
LOOKING AHEAD...THE FRONTAL BOUNDARY OVER THE SW N ATLC IS
FORECAST TO MOVE EASTWARD THROUGH SAT AND WEAKEN OVER THE
CENTRAL ATLC SUN.

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

$$
COBB


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