[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 100521
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SAT JAN 10 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
0445 UTC.

...THE ITCZ...

ITCZ IS CENTERED ALONG 8N12W 4N20W 2N28W 1N35W AND INTO NE
BRAZIL NEAR 2S45W. SCATTERED MODERATE CONVECTION IS FROM 5N-7N
BETWEEN 10W-13W. SCATTERED MODERATE CONVECTION IS ALSO FROM
1N-5N BETWEEN 20W-27W. SIMILAR CONVECTION IS FROM 1N-3N BETWEEN
31W-36W.

...DISCUSSION...

GULF OF MEXICO...
WESTERLY FLOW ALOFT IS PRESENT ACROSS THE GULF REGION...WHERE
DEEP LAYER DRY AIR AND SUBSIDENCE ARE RESULTING IN GENERALLY
FAIR WEATHER CONDITIONS. THE RETURN FLOW AROUND A 1027 MB
SURFACE HIGH SE OF NORTH CAROLINA NEAR 34N76W IS BRINGING S TO
SE WINDS OF 10 TO 15 KT ACROSS MUCH OF THE GULF REGION. FARTHER
TO THE NORTH...A DEEP LAYER TROUGH OVER THE W CONUS IS MOVING
WESTWARD...WITH AN ASSOCIATED SURFACE FRONT CURRENTLY EXTENDING
FROM THE SOUTHERN PLAINS INTO THE SOUTHERN ROCKY MOUNTAIN REGION
OF THE CONUS. THIS FRONT IS FORECAST TO APPROACH THE NW GULF ON
SATURDAY BEFORE IT MOVES SOUTHWARD ACROSS THE GULF THROUGH EARLY
NEXT WEEK. INCREASED N WINDS AND COOLER CONDITIONS ARE FORECAST
IN THE WAKE OF THIS FRONT...WITH GALE CONDITIONS EXPECTED ACROSS
PORTIONS OF THE SW GULF FOR SATURDAY NIGHT AND SUNDAY.

CARIBBEAN SEA...
AN UPPER RIDGE IS PRESENT ACROSS THE CARIBBEAN REGION...WITH THE
UPPER RIDGE AXIS EXTENDING FROM N VENEZUELA NEAR 11N70W TO
15N72W TO 19N73W. SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS
ASSOCIATED WITH THIS UPPER RIDGE ARE RESULTING IN GENERALLY FAIR
WEATHER CONDITIONS ACROSS MUCH OF THE CARIBBEAN SEA.
HOWEVER...ACROSS THE SW CARIBBEAN...DEEP MOISTURE IS BEING
TRANSPORTED NORTHWARD TO THE W OF THE UPPER RIDGE AXIS...WHICH
IS RESULTING IN ISOLATED SHOWERS S OF 11N BETWEEN 75W AND 79W.
MODERATE TO FRESH TRADE WINDS ARE PRESENT ACROSS THE CARIBBEAN
SEA. THESE TRADE WINDS ARE FORECAST TO INTENSIFY OVER THE NEXT
FEW DAYS AS A 1027 MB SURFACE HIGH SE OF NORTH CAROLINA NEAR
34N76W MOVES SOUTHEASTWARD. THE STRONGEST WINDS...UP TO 30
KT...ARE PRESENT NEAR THE COAST OF COLOMBIA.

ATLANTIC OCEAN...
A SURFACE COLD FRONT EXTENDS FROM 23N72W TO 27N60W TO 32N54W TO
NE OF THE DISCUSSION AREA...WITH LOW LEVEL CONVERGENCE
SUPPORTING SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THIS
SURFACE COLD FRONT. TO THE W...A DISSIPATING SURFACE COLD FRONT
EXTENDS FROM 27N76W TO 28N66W TO 31N59W...AND A SURFACE TROUGH
EXTENDS FROM 31N59W TO 32N57W TO NE OF THE DISCUSSION
AREA...WITH LOW LEVEL CONVERGENCE SUPPORTING ISOLATED SHOWERS
WITHIN 60 NM EITHER SIDE OF THIS DISSIPATING SURFACE COLD FRONT
AND THIS SURFACE TROUGH. IN THE WAKE OF THE SURFACE COLD FRONTS
AND SURFACE TROUGH...DEEP LAYER DRY AIR AND SUBSIDENCE ARE
RESULTING IN GENERALLY FAIR WEATHER CONDITIONS...WITH WESTERLY
FLOW ALOFT ACROSS THE SW ATLC. THE SUBSIDENCE IS BEING ENHANCED
AROUND A 1027 MB SURFACE HIGH SE OF NORTH CAROLINA NEAR 34N76W.
BOTH OF THE SURFACE FRONTS AND SURFACE TROUGH ARE ASSOCIATED
WITH A DEEP TROUGH ACROSS THE W ATLC N OF THE DISCUSSION AREA.
FARTHER TO THE E...A 1029 MB SURFACE HIGH IS PRESENT NEAR
29N39W. SUBSIDENCE ASSOCIATED WITH THIS SURFACE HIGH IS
RESULTING IN FAIR WEATHER CONDITIONS ACROSS MUCH OF THE E ATLC.
HOWEVER...AN UPPER TROUGH EXTENDS FROM 24N33W TO AN UPPER LOW
NEAR 21N41W TO 12N54W. ATMOSPHERIC INSTABILITY ASSOCIATED WITH
THIS UPPER LOW AND UPPER TROUGH IS RESULTING IN SCATTERED
SHOWERS FROM 11N-18N BETWEEN 33W-38W. THIS ACTIVITY IS BEING
ENHANCED BY UPPER LEVEL DIVERGENCE IN THE NE QUADRANT OF AN
UPPER LEVEL JET MAXIMUM LOCATED S OF THE UPPER LOW. ALSO...LOW
LEVEL CONVERGENCE ASSOCIATED WITH A 1015 MB SURFACE LOW CENTERED
NEAR 29N15W IS RESULTING IN ISOLATED SHOWERS N OF 26N E OF 18W.
ACROSS THE TROPICAL ATLC...AN UPPER RIDGE AXIS IS CENTERED FROM
7N12W TO 6N23W TO 1N36W. UPPER LEVEL DIVERGENCE NEAR THIS UPPER
RIDGE IS ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ.

$$
COHEN




This weather bulletin was brought to you by:
www.nashvilleweather.net