[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131146
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI NOV 13 2009

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 8N12W 7N20W 9N36W 9N39W 9N61W. A
SURFACE TROUGH IS ANALYZED FROM 13N34W TO 8N38W. THIS SURFACE
TROUGH HAS BEEN MOVING WNW AT 12 KT OVER THE PAST 24 HOURS.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-11N
BETWEEN 15W-28W. ELSEWHERE...SCATTERED MODERATE CONVECTION IS
FROM 6N-13N BETWEEN 48W-54W.

...DISCUSSION...

GULF OF MEXICO...
NLY SURFACE WINDS ARE ACROSS THE GULF OF MEXICO E OF 92W AS A
SURFACE RIDGE AXIS EXTENDS FROM A 1016 MB HIGH CENTERED OVER
LOUISIANA NEAR 31N93W TO THE BAY OF CAMPECHE AND PORTIONS OF
CENTRAL AMERICA. ALOFT...AN UPPER LEVEL SHORTWAVE TROUGH AXIS
EXTENDS FROM THE SOUTHERN FLORIDA PENINSULA THROUGH 24N90W TO
OVER CENTRAL MEXICO NEAR 20N98W. DRY AIR AND STRONG SUBSIDENCE
IS NOTED ON WATER VAPOR IMAGERY ACROSS THE GULF PROVIDING
GENERALLY STABLE CONDITIONS AND PATCHY STRATOCUMULUS CLOUDINESS.
AS THE SURFACE RIDGE DRIFTS EASTWARD...WINDS WILL REMAIN LIGHT
NEAR THE RIDGE AXIS WITH SELY RETURN FLOW EXPECTED TO DEVELOP
ACROSS THE WESTERN WATERS SATURDAY EAST OF A COLD FRONT FORECAST
TO MOVE OFF THE TEXAS COAST MONDAY AFTERNOON.

CARIBBEAN SEA...
A COLD FRONT EXTENDS ACROSS EASTERN CUBA AND INTO THE NW
CARIBBEAN NEAR 21N78W EXTENDING SW TO GRAND CAYMAN ISLAND NEAR
19N81W. A SURFACE TROUGH IS ANALYZED SE OF THE COLD FRONT AND
EXTENDS INTO THE WESTERN CARIBBEAN NEAR 21N77W CONTINUING SSW TO
14N81W. LOW-LEVEL CONVERGENCE NEAR THE COLD FRONT AND SURFACE
TROUGH IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN
120 NM EITHER SIDE OF THE SURFACE TROUGH. MORE CONCENTRATED
SHOWERS AND TSTMS ARE OCCURRING OVER THE SW CARIBBEAN...SOUTHERN
NICARAGUA...AND COSTA RICA FROM 7N-14N BETWEEN 76W-84W. THIS
ACTIVITY S OF THE SURFACE TROUGH IS ENHANCED BY UPPER LEVEL
DIFFLUENCE DUE TO AN UPPER LEVEL ANTICYCLONIC CIRCULATION
CENTERED NEAR 10N80W. THE UPPER LEVEL RIDGE EXTENDS ACROSS THE
BASIN EASTWARD TO 58W IN THE TROPICAL NORTH ATLC. AN AREA OF
HIGHER VALUES OF PRECIPITABLE WATER ARE EAST OF THE LESSER
ANTILLES BETWEEN 55W-60W AND CONTINUES TO ADVECT WESTWARD ON
10-15 KT TRADEWINDS. EXPECT INCREASED CLOUDINESS AND POSSIBLE
ISOLATED SHOWERS OVER THE EASTERN CARIBBEAN E OF 65W AND THE
LESSER ANTILLES OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N72W AND EXTENDS
S-SW ALONG 30N72W TO THE SE BAHAMAS NEAR 24N75W TO EASTERN CUBA
AND INTO THE NW CARIBBEAN. POSSIBLE ISOLATED SHOWERS ARE WITHIN
60 NM EITHER SIDE OF THE FRONT. E OF THE FRONT...A SURFACE
TROUGH IS ANALYZED FROM 31N70W TO 25N72W AND OVER EASTERN CUBA.
SCATTERED SHOWERS AND TSTMS ARE OCCURRING WITHIN 60 NM EITHER
SIDE OF THE SURFACE TROUGH WITH ENHANCED CONVECTION N OF 25N
BETWEEN 65W-70W. THIS FRONT IS BEING DRIVEN BY AN UPPER LEVEL
LOW CENTERED OFF THE NORTH CAROLINA COAST NEAR 34N75W AND UPPER
LEVEL TROUGHING DIPPING TO 25N W OF 69W. UPPER LEVEL DIFFLUENCE
E OF THE UPPER TROUGH AXIS IS ALSO AIDING IN ENHANCING THE
CONVECTION. FARTHER E...A 1003 MB LOW IS CENTERED NEAR 33N62W.
LOW-LEVEL CONVERGENCE EAST OF THE LOW CENTER FOCUSED ON A
WEAKENING STATIONARY FRONT EXTENDING FROM THE LOW TO 31N55W IS
GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS N OF 29N BETWEEN
50W-60W. THIS CONVECTION IS BEING ENHANCED BY A LARGE AREA OF
UPPER LEVEL DIFFLUENCE ACROSS THE WESTERN ATLC AND INTO THE
CENTRAL ATLC N OF 24N BETWEEN 50W-70W. OVER THE CENTRAL ATLC...A
COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N38W AND EXTENDS
WESTWARD ALONG 31N TO 53W. ISOLATED SHOWERS AND TSTMS ARE WITHIN
90 NM EITHER SIDE OF THE FRONT. ACROSS THE REMAINDER OF THE
CENTRAL AND EASTERN ATLC...A BROAD SURFACE RIDGE DOMINATES
ANCHORED BY A 1018 MB HIGH CENTERED NEAR 26N31W. THIS SURFACE
HIGH IS SUPPORTED BY A BROAD UPPER LEVEL RIDGE WITH AXIS ALONG
40W. EAST OF THE UPPER LEVEL RIDGE...AN UPPER LEVEL TROUGH AXIS
DIPS SOUTHWARD TO 14N E OF 27W AND CONTINUES SHEARING MOISTURE
FROM THE ITCZ TO THE NE SUPPORTING SCATTERED SHOWERS SE OF A
LINE FROM NORTHERN MAURITANIA NEAR 21N17W TO SW OF THE CAPE
VERDE ISLANDS NEAR 13N27W.

$$
HUFFMAN





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