[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 122353
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST FRI NOV 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...

A 1009 MB LOW IS LOCATED IN THE SW CARIBBEAN SEA CENTERED NEAR
11N76W THAT CONTINUES TO PRODUCE AN AREA OF UNORGANIZED WIDELY
SCATTERED MODERATE CONVECTION COVERING THE AREA FROM 09N-16N
BETWEEN 73W-80W. AS THIS AREA OF DISTURBED WEATHER HAS MOVED
WESTWARD OVER THE PAST COUPLE OF DAYS...IT CONTINUES TO LOCATE
ITSELF BENEATH AN UPPER LEVEL RIDGE ACROSS THE WESTERN CARIBBEAN
SEA AND PORTIONS OF CENTRAL AMERICA. THIS IS PROVIDING AN UPPER
LEVEL DIFFLUENT ENVIRONMENT FOR THE ONGOING CONVECTION...
HOWEVER...THE CONVECTION LACKS LOWER LEVEL CYCLONIC SUPPORT AS E
TO NE WINDS WERE DEPICTED ON AN EARLIER 12/1458 UTC ASCAT PASS.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 07N12W 04N21W 07N35W 06N42W 08N59W.
A SURFACE TROUGH IS ANALYZED WITHIN THE ITCZ REGION FROM 03N37W
TO 13N32W. WEAK LOW-LEVEL CYCLONIC FLOW IS IN THE VICINITY OF
THE SURFACE TROUGH AXIS SCATTERED MODERATE AND ISOLATED STRONG
CONVECTION OCCURRING FROM 06N-11N BETWEEN 28W-35W. THIS AREA OF
CONVECTION CONTINUES TO BE ENHANCED BY AN UPPER LEVEL TROUGH
WITH AXIS ALONG 30W AND A BASE VERY NEAR THE ONGOING CONVECTION
AT 08N32W. ELSEWHERE...ISOLATED MODERATE CONVECTION IS FROM
05N-08N BETWEEN 25W-28W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE EXTENDS FROM THE YUCATAN PENINSULA
NORTHWARD TO OVER THE SE CONUS AND SUPPORTS SURFACE RIDGING THAT
ENVELOPES THE ENTIRE GULF AND FLORIDA PENINSULA THIS EVENING.
OVERALL...MOSTLY FAIR CONDITIONS PERSIST...HOWEVER...WEST OF THE
RIDGE AXIS ESTABLISHED ALONG 88W...MOIST E TO SE LOW-LEVEL
RETURN FLOW IS GENERATING ISOLATED SHOWERS FROM 20N-25N BETWEEN
92W-95W. THIS SOUTHERLY RETURN FLOW IS FORECAST TO REMAIN IN
PLACE OVER THE WESTERN GULF AS THE NEXT COLD FRONT...CURRENTLY
OVER CENTRAL TEXAS...EMERGES OFF THE TEXAS COAST AND INTO THE NW
GULF WATERS EARLY SATURDAY.

CARIBBEAN SEA...
A DRY AND SUBSIDENT AIRMASS IS LOCATED OVER THE NW CARIBBEAN DUE
TO AN UPPER LEVEL RIDGE AXIS EXTENDING FROM NORTHERN COLOMBIA TO
SOUTHERN MEXICO NEAR 18N92W. THIS AREA OF GENERALLY FAIR WEATHER
COINCIDES WITH SURFACE RIDGING THAT EXTENDS FROM THE GULF OF
MEXICO AND REMAINS N OF 16N W OF 75W. FARTHER SE...THE SPECIAL
FEATURE 1009 MB LOW CONTINUES GENERATING SCATTERED SHOWERS AND
TSTMS OVER THE SW CARIBBEAN S OF 16N BETWEEN 73W-80W. BROAD
UPPER LEVEL TROUGHING EXISTS OVER THE NORTH CENTRAL CARIBBEAN N
OF 16N E OF 76W AND EXHIBITS OVERALL DRY AIR ALOFT ON WATER
VAPOR IMAGERY THIS EVENING. THIS TROUGHING SUPPORTS A STATIONARY
FRONT THAT ENTERS THE BASIN OVER THE LEEWARD ISLANDS NEAR
BARBUDA AND EXTENDS SW TO NEAR 16N66W WITH POSSIBLE ISOLATED
SHOWERS LOCATED N OF 16N E OF 68W. FINALLY...A COLD FRONT IS
POSITIONED ACROSS THE SW NORTH ATLC AND TRAILS ALONG 20N BETWEEN
68W-74W...NORTH OF HISPANIOLA. LOW-LEVEL MOISTURE CONTINUES TO
POOL IN THE VICINITY AND SOUTH OF THE WEAKENING FRONT WITH
POSSIBLE ISOLATED SHOWERS EXPECTED TO PERSIST THROUGH SATURDAY
OVER PUERTO RICO...HISPANIOLA...AND PORTIONS OF JAMAICA.

ATLANTIC OCEAN...
A DEEP LAYERED 999 MB GALE FORCE LOW REMAINS SPINNING OVER THE
WESTERN NORTH ATLC CENTERED NEAR 33N63W. THE MIDDLE TO UPPER
LEVEL TROUGHING DIPS WELL INTO THE NORTH-CENTRAL CARIBBEAN SEA
AND REMAINS LARGELY INFLUENTIAL BETWEEN 55W-80W OVER THE W ATLC
WATERS. ON THE SOUTHEASTERN PERIPHERY OF THE TROUGHING...A
STATIONARY FRONT ENTERS THE DISCUSSION AREA NEAR 32N45W AND
EXTENDS SW INTO A 1009 MB LOW CENTERED NEAR 29N51W THEN ALONG
25N53W TO THE NE CARIBBEAN SEA NEAR 17N63W. SCATTERED SHOWERS
ARE WITHIN 180 NM SE OF THE FRONT BETWEEN 48W-60W. AS ANOTHER
SHORTWAVE TROUGH ROTATES AROUND THE MAIN DEEP LAYERED LOW...A
REINFORCING COLD FRONT IS ANALYZED WEST OF THE STATIONARY FRONT
AS A COLD FRONT FROM 32N51W 23N60W TO NW OF HISPANIOLA NEAR
20N74W. ISOLATED SHOWERS ARE OCCURRING WEST OF THE COLD FRONT TO
CUBA AND THE FLORIDA PENINSULA. FARTHER EAST...THE REMAINDER OF
THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE
ANCHORED BY A 1023 MB HIGH CENTERED E OF THE MADEIRA ISLANDS
NEAR 33N14W.

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

$$
HUFFMAN




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