[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 140554
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SAT NOV 14 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 7N11W 5N16W 6N29W 8N32W 8N38W
7N41W 4N52W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 3N-9N
BETWEEN 17W-28W. A SURFACE TROUGH IS ANALYZED ALONG 31W FROM
4N-11N WITH SCATTERED SHOWERS FROM 9N-14N BETWEEN 27W-33W. A
SECOND SURFACE TROUGH IS ANALYZED FROM 13N34W TO A 1010 MB LOW
NEAR 9N39W AND CONTINUING TO 5N41W. SCATTERED SHOWERS ARE FROM
4N-14N BETWEEN 33W-42W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE EXTENDS ACROSS THE CENTRAL GULF ALONG 90W
ANCHORED ON A 1013 MB HIGH CENTERED OVER EASTERN LOUISIANA NEAR
30N90W. THIS RIDGE IS PROVIDING GENERALLY FAIR WEATHER ACROSS
THE GULF WITH LIGHT NLY WINDS E OF 90W AND SLY RETURN FLOW UP TO
15 KT W OF 90W. ALOFT...AN UPPER LEVEL RIDGE EXTENDS FROM 26N95W
NE ACROSS MUCH OF THE EASTERN CONUS AND AN UPPER LEVEL LOW IS
LOCATED SOUTH OF THIS RIDGE CENTERED OVER EASTERN MEXICO NEAR
21N97W. STRONG SUBSIDENCE IS SUPPORTING A RELATIVELY COOL AND
DRY AIRMASS OVER MUCH OF THE GULF AS NOTED IN WATER VAPOR
IMAGERY. THE SURFACE RIDGE IS FORECAST TO SLIDE GRADUALLY
EASTWARD THROUGH EARLY MONDAY WITH SE RETURN FLOW SPREADING
EASTWARD AS WELL AHEAD OF THE NEXT COLD FRONT TO ENTER THE NW
GULF WATERS MONDAY AFTERNOON.

CARIBBEAN SEA...
A STATIONARY FRONT EXTENDS FROM THE W ATLC ACROSS ERN CUBA NEAR
21N77W INTO THE NW CARIBBEAN TO GRAND CAYMAN ISLANDS NEAR
19N82W. A PRE-FRONTAL SURFACE TROUGH SE OF THE FRONT EXTENDS
FROM 20N75W ACROSS JAMAICA TO 12N82W. ISOLATED SHOWERS ARE
WITHIN 90 NM EITHER SIDE OF THE SURFACE TROUGH. THIS PAIR OF
BOUNDARIES ARE SUPPORTED ALOFT BY AN UPPER LEVEL LOW IN THE W
ATLC AND ASSOCIATED TROUGH AXIS THAT EXTENDS OVER THE SE BAHAMAS
AND CUBA TO THE YUCATAN CHANNEL. FARTHER SOUTH...SCATTERED
SHOWERS AND ISOLATED TSTMS ARE OCCURRING OVER THE SW CARIBBEAN S
OF 12N BETWEEN 77W-84W IN ASSOCIATION WITH LOW-LEVEL SURFACE
CONVERGENCE AND UPPER DIFFLUENCE ASSOCIATED WITH A BROAD UPPER
LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 13N80W. UPPER LEVEL
RIDGING COVERS THE REMAINDER OF THE CARIBBEAN BASIN WITH
MODERATE SUBSIDENCE AND DRY AIR ALOFT. A FEW ISOLATED LOW-LEVEL
SHOWERS HOWEVER ARE ACROSS HISPANIOLA AND ADJACENT COASTAL
WATERS N OF 17N BETWEEN 69W-76W.

ATLANTIC OCEAN...
A COMPLEX AREA OF LOW PRESSURE IS LOCATED OFF THE NORTH CAROLINA
COAST AND CENTERED AS A 996 MB LOW NEAR 34N74W. A STATIONARY
FRONT EXTENDS EAST OF THE SURFACE CIRCULATION AND ENTERS THE
DISCUSSION AREA NEAR 32N69W AND CONTINUES ALONG 29N70W TO THE SE
BAHAMAS AND THEN TO EASTERN CUBA NEAR 21N77W. A SURFACE TROUGH
IS ANALYZED TO THE E ALONG 32N66W TO 24N70W AND ACROSS THE TURKS
AND CAICOS ISLANDS TO EASTERN CUBA NEAR 20N75W. SCATTERED
SHOWERS AND TSTMS ARE PRIMARILY ASSOCIATED WITH THE SURFACE
TROUGH AND ARE OCCURRING WITHIN 200 NM E OF THE BOUNDARY S OF
25N. MORE CONCENTRATED CONVECTION IS FROM 25N-32N BETWEEN
50W-68W. THESE BOUNDARIES ARE SUPPORTED BY AN UPPER LEVEL LOW
CENTERED OFF THE NORTH CAROLINA COAST NEAR 34N73W AND ASSOCIATED
TROUGHING THAT DIPS SOUTHWARD TO 20N. UPPER LEVEL DIFFLUENCE E
OF THE TROUGH AXIS ALONG 70W IS ALSO ENHANCING THE CURRENT
CONVECTION. TO THE E OVER THE CENTRAL ATLC...A 1010 MB LOW IS
CENTERED NEAR 32N29W WITH A COLD FRONT THAT EXTENDS SW TO 28N40W
AND THEN NW TO 31N48W. ISOLATED SHOWERS ARE WITHIN 90 NM E OF
THE FRONT. THIS FRONT IS FAIRLY WEAK DUE TO PREDOMINANTLY
WESTERLY UPPER LEVEL FLOW N OF 29N E OF 45W. AN UPPER LEVEL
TROUGH IS LOCATED SW OF THE UPPER LEVEL WESTERLY FLOW WITH AXIS
FROM 24N45W TO SURINAME IN SOUTH AMERICA NEAR 6N56W. UPPER LEVEL
DIFFLUENCE E OF THE UPPER TROUGH IS GENERATING POSSIBLE ISOLATED
SHOWERS FROM 8N-17N BETWEEN 40W-51W. THE REMAINDER OF THE
EASTERN ATLC IS UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE
ANCHORED BY A 1020 MB HIGH NEAR 25N26W.

$$
HUFFMAN



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