[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141800
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED APR 14 2010

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1645 UTC...

...THE ITCZ...
THE ITCZ AXIS IS CENTERED FROM SRN LIBERIA NEAR 5N8W ALONG 6N20W
4N30W 4N40W 6N50W AND INTO NE SOUTH AMERICA NEAR 5N56W. NUMEROUS
STRONG CONVECTION IS INLAND OVER AFRICA FROM 4N-9N BETWEEN
6W-10W. SIMILAR ACTIVITY IS FROM 1N-6N BETWEEN 11W-18W.
SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N-6N BETWEEN
24W-35W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM
1N-7N BETWEEN 40W-53W. SCATTERED MODERATE/STRONG CONVECTION IS
ALSO FROM 6N-10N BETWEEN 58W-60W.

...DISCUSSION...

THE GULF OF MEXICO...
A SURFACE RIDGE BUILDS ACROSS THE GULF OF MEXICO FROM A 1037 MB
HIGH N OF THE GREAT LAKES PROVIDING GENERALLY FAIR WEATHER
ACROSS THE N CENTRAL AND ERN GULF. HOWEVER...A SHORTWAVE UPPER
LEVEL TROUGH OVER THE WRN GULF IS ENHANCING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS IN THE S CENTRAL GULF FROM
21N-25N BETWEEN 85W-93W...AND ACROSS THE SRN TIP OF TEXAS FROM
24N-28N W OF 93W. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF
THE BASIN WITH AXIS EXTENDING DOWN THE FLORIDA PENINSULA. WATER
VAPOR IMAGERY INDICATES SIGNIFICANTLY DRY AIR ACROSS THE NE GULF
SUPPORTING CLEAR SKIES ACROSS THIS AREA. SURFACE OBSERVATIONS
INDICATE MAINLY E WINDS OF 20-25 KTS ACROSS THE GULF. EXPECT THE
SURFACE RIDGE TO REMAIN WHILE SHOWERS/THUNDERSTORMS CONTINUE
ACROSS THE CENTRAL GULF.

THE CARIBBEAN SEA...
MUCH OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER
TODAY INFLUENCED BY AN UPPER LEVEL RIDGE ACROSS THE BASIN
EXTENDING FROM THE FLORIDA PENINSULA. HOWEVER...ISOLATED SHOWERS
ARE NOTED ACROSS THE NW CARIBBEAN N OF 19N W OF 82W DUE TO THE
APPROACH OF A SHORTWAVE UPPER LEVEL TROUGH ACROSS THE WRN GULF.
ISOLATED SHOWERS ARE ALSO OFF THE COAST OF PANAMA AND NRN
COLOMBIA NEAR A 1009 MB LOW OVER NRN COLOMBIA NEAR 8N74W. A
SURFACE TROUGH EXTENDS FROM THE CENTRAL ATLC ACROSS PUERTO RICO
TO NEAR 18N67W. SCATTERED SHOWERS ARE N OF 17N BETWEEN 65W-68W.
TOTAL PRECIPITABLE WATER IMAGERY INDICATES A LARGE AREA OF
ENHANCED LOW-LEVEL MOISTURE THAT HAS REMAINED ACROSS THE LEEWARD
ISLANDS FOR THE PAST SEVERAL DAYS SUPPORTING CONTINUED SHOWER
ACTIVITY OVER THE AREA. IN FACT...GUADELOUPE REPORTED 2.85
INCHES OF RAIN FOR THE PAST 24 HR TOTAL. A WEAK
PRESSURE GRADIENT IS PROVIDING MODERATE TRADEWINDS ACROSS MUCH
OF THE BASIN. EXPECT THE SURFACE TROUGH ACROSS PUERTO RICO TO
DRIFT NE...WHILE ENHANCED MOISTURE CONTINUES TO IMPACT THE
LEEWARD ISLANDS.

THE ATLANTIC OCEAN...
THE FAR W ATLC IS INFLUENCED BY A SURFACE RIDGE BUILDING FROM
THE N PROVIDING GENERALLY FAIR WEATHER W OF 67W. THE SURFACE
RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE EXTENDING DOWN THE
FLORIDA PENINSULA. A DEEP LAYER TROUGH IMPACTS THE W CENTRAL
ATLC ENHANCING A LARGE AREA OF SHOWER ACTIVITY. THE ASSOCIATED
SURFACE TROUGH EXTENDS FROM 31N61W TO CENTRAL PUERTO RICO ALONG
25N64W TO 18N67W. MOST OF THE SHOWER ACTIVITY IS E OF THE TROUGH
AXIS WITHIN 500 NM. MUCH OF THE ACTIVITY IS ENHANCED BY
DIFFLUENT FLOW ALOFT TO THE E SIDE OF THE UPPER LEVEL TROUGH
ALONG 63W. ANOTHER SURFACE TROUGH IS NOTED E OF THE LESSER
ANTILLES FROM 18N51W TO 15N52W. ISOLATED SHOWERS ARE WITHIN 150
NM EITHER SIDE OF THE AXIS. AS MENTIONED IN THE CARIBBEAN SEA
SECTION...THERE IS A LARGE AREA OF ENHANCED MOISTURE ASSOCIATED
WITH THE DEEP LAYER TROUGH CONCENTRATED OVER THE LEEWARD
ISLANDS. GUADELOUPE HAS ALREADY REPORTED A 24 HR PRECIPITATION
TOTAL OF 2.85 INCHES. THIS AREA OF LOW-LEVEL MOISTURE IS
EXPECTED TO CONTINUE IMPACTING THE LEEWARD ISLANDS FOR AT LEAST
THE NEXT 24 HRS. FARTHER E...A WEAK SURFACE RIDGE BUILDS ACROSS
THE REMAINDER OF THE CENTRAL ATLC BETWEEN 35W-50W PROVIDING FAIR
WEATHER OVER THIS PORTION OF THE BASIN. THIS RIDGE IS SUPPORTED
BY A NARROW UPPER LEVEL RIDGE ALONG 45W. ACROSS THE ERN ATLC...A
PAIR OF SURFACE TROUGHS...REMNANTS OF FRONTAL BOUNDARIES REMAIN
ASSOCIATED WITH A STATIONARY 993 MB LOW SW OF PORTUGAL NEAR
35N16W. ONE TROUGH AXIS EXTENDS ALONG 32N13W ACROSS THE CANARY
ISLANDS TO 26N18W 22N29W. THE SECOND TROUGH EXTENDS ALONG 31N18W
27N25W 27N29W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 30 NM EITHER
SIDE OF BOTH TROUGH AXIS. THIS SYSTEM IS SUPPORTED BY AN UPPER
LEVEL TROUGH CENTERED E OF THE AZORES ISLANDS NEAR 36N23W.

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

$$

WALTON



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