[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 040529
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU APR 04 2013

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
0445 UTC.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 7N12W AND CONTINUES ALONG 3N14W TO THE EQUATOR NEAR 22W
WHERE THE ITCZ BEGINS AND CONTINUES ALONG THE EQUATOR TO 30W
THEN ALONG 1N36W THEN S OF THE EQUATOR NEAR 39W. CLUSTERS OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N TO
JUST S OF THE EQUATOR BETWEEN 5W-25W. CLUSTERS OF SCATTERED
MODERATE CONVECTION ARE FROM 1N-3N BETWEEN 30W-36W.

...DISCUSSION...

GULF OF MEXICO...
A BROAD UPPER TROUGH DIPS S FROM THE CENTRAL PLAIN STATES OVER
MEXICO AND THE FAR NW GULF WHILE A BROAD UPPER RIDGE COVERS THE
REMAINDER OF THE GULF ANCHORED OVER SOUTH AMERICA. A COMPLEX
SURFACE PATTERN EXISTS OVER THE GULF AT 04/0300 UTC WITH A
1011 MB LOW OFF THE COAST OF LOUISIANA NEAR 28N90W AND A COLD
FRONT EXTENDING SW ALONG 25N93W TO INLAND OVER MEXICO N OF
TAMPICO NEAR 23N98W. A WARM FRONT EXTENDS E FROM THE 1011 MB LOW
ALONG 29N86W TO 28N83W. A 1008 MB LOW IS S OF THE FRONT NEAR
23N94W WITH A SURFACE TROUGH EXTENDING S TO INLAND OVER S MEXICO
NEAR VERACRUZ. SCATTERED TO HEAVY SHOWERS WITH SCATTERED
THUNDERSTORMS ARE OVER THE N/CENTRAL GULF FROM 24N-28N W OF 86W
TO THE COLD FRONT. SCATTERED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS COVER THE REMAINDER OF THE N GULF N OF A LINE FROM
TAMPA FLORIDA TO TUXPAN MEXICO. THIS IS LEAVING THE S GULF UNDER
MOSTLY CLEAR SKIES TONIGHT. THE 1011 MB LOW WILL SHIFT NE OF THE
GULF TO 31N85W WHILE DEEPENING TO 1006 MB BY THU EVENING WITH
THE FRONT EXTENDING FROM THE LOW TO 26N86W TO 18N94W THEN FROM
SW FLORIDA TO THE YUCATAN PENINSULA FRI MORNING BEFORE SHIFTING
SE OF THE GULF BY FRI AFTERNOON. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT WITH SOUTHERLY RETURN FLOW ACROSS THE GULF LATE
SAT THROUGH MON.

CARIBBEAN SEA...
A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN AND MOST OF THE GULF
OF MEXICO ANCHORED INLAND OVER SOUTH AMERICA. RELATIVE TIGHT
PRESSURE GRADIENT EXISTS BETWEEN THE LOWER PRESSURE OF SOUTH
AMERICA AND THE SURFACE RIDGE OVER THE W ATLC PRODUCING FRESH TO
STRONG EASTERLY TRADE WINDS ACROSS THE S/CENTRAL CARIBBEAN WITH
MODERATE TRADE WINDS ELSEWHERE. THE MONSOON TROUGH EXTENDS
ACROSS PANAMA INTO THE EXTREME SW CARIBBEAN CROSSING COSTA RICA
INTO THE E PACIFIC REGION. SCATTERED SHOWERS ARE S OF 11N
BETWEEN COLOMBIA AND COSTA RICA. WATER VAPOR IMAGERY INDICATES
STRONG SUBSIDENCE ACROSS MOST OF THE BASIN GIVING THE CARIBBEAN
FAIR CONDITIONS ACROSS THE REMAINDER OF THE AREA. TRADE WINDS
WILL PREVAIL THROUGH SUN. AN EXCEPTION WILL BE FRESH TO STRONG
WINDS IN THE GULF OF HONDURAS WHICH WILL OCCUR THROUGH THU
MORNING. A WEAK COLD FRONT WILL MOVE SE OF THE YUCATAN CHANNEL
LATE THU NIGHT GRADUALLY WEAKENING OVER THE NW CARIBBEAN AND
DISSIPATING BY SAT.

ATLANTIC OCEAN...
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE OVER
THE FAR W ATLC N OF 27N W OF 76W ASSOCIATED WITH THE FRONTAL
SYSTEM IN THE GULF OF MEXICO. BROAD UPPER RIDGE FROM THE
CARIBBEAN COVERS THE W ATLC. A WEAK SURFACE RIDGE COVERS THE
ATLC ANCHORED BY A 1024 MB HIGH W OF BERMUDA NEAR 32N67W. AN
UPPER TROUGH EXTENDS OVER THE W/CENTRAL ATLC N OF 24N FROM 44W-
60W SUPPORTING A WEAK COLD FRONT THAT ENTERS THE REGION NEAR
32N53W TO 24N63W. ISOLATED SHOWERS ARE WITHIN 90 NM E OF THE
FRONT. A LARGE SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC
ANCHORED BY A 1029 MB HIGH NEAR 31N39W GIVING THE REMAINDER OF
THE ATLC FAIR WEATHER TONIGHT. SOUTHERLY RETURN FLOW WILL
INCREASE THROUGH THU OVER THE W ATLC AHEAD OF A SURFACE LOW
CURRENTLY IN THE GULF OF MEXICO THAT WILL TRACK NE OVER THE N
ATLC LATE THU NIGHT DRAGGING A COLD FRONT INTO THE W ATLC FRI.
THE FRONT WILL REACH FROM 32N74W TO THE STRAITS OF FLORIDA FRI
EVENING THEN FROM NEAR BERMUDA TO NEAR THE WINDWARD PASSAGE SAT
EVENING WHILE WEAKENING. THE FRONT WILL STALL OUT AS IT MOVES
INTO THE CENTRAL ATLC SUN DISSIPATING BY MON AS HIGH PRESSURE
BUILDS IN OVER THE W ATLC.

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

$$
PAW


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