[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161734
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST THU DEC 16 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
1700 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N10W 4N22W 4N35W 4N45W 1N55W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-8N
BETWEEN 12W-16W. SIMILAR ACTIVITY IS FROM 2N-7N BETWEEN 21W-30W.
SOME OF THIS ACTIVITY IS ENHANCED BY AN EMBEDDED SURFACE TROUGH
ALONG 11N18W TO 4N25W. A SHEAR LINE IS N OF THE ITCZ AXIS ALONG
8N32W 10N43W 6N53W SUPPORTING SCATTERED MODERATE/ISOLATED STRONG
CONVECTION WITHIN 75 NM EITHER SIDE OF THE AXIS BETWEEN 40W-46W.
STRONG CONVECTION IS ALSO INLAND OVER NRN BRAZIL FROM EQ-4N
BETWEEN 49W-53W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES A VERY DRY AND STABLE AIRMASS WITH
MAINLY ZONAL WLY FLOW ALOFT COVERS THE GULF OF MEXICO
MAINTAINING FAIR CONDITIONS BASIN-WIDE. A SURFACE RIDGE
CONTINUES TO DOMINATE THE AREA EXTENDING FROM A 1020 MB HIGH E
OF CAPE CANAVERAL. ANTI-CYCLONIC FLOW IS AROUND THE RIDGE WITH
WINDS REACHING 15 KT IN THE ERN GULF AND UP TO 25 KTS IN THE WRN
GULF. STRONG SLY WINDS SHOULD CONTINUE ACROSS THE WRN PORTION AS
A COLD FRONT APPROACHES THE TEXAS COAST LATER TONIGHT. AS THE
FRONTAL SYSTEM MOVES INTO THE AREA...THE SURFACE RIDGE IS
FORECAST TO SHIFT EWD.

CARIBBEAN SEA...
THE DRY AND STABLE AIRMASS ACROSS THE GULF OF MEXICO ALSO
SPREADS ACROSS THE NW CARIBBEAN BRINGING FAIR CONDITIONS. A
SHEAR LINE EXTENDS FROM THE NRN LEEWARD ISLANDS NEAR 18N63W TO S
OF HISPANIOLA NEAR 15N73W DEPICTING AN AREA OF SPEED CONVERGENCE
WHICH IS CAUSING AN AREA OF CLOUDINESS AND POSSIBLE SHOWERS
WITHIN 120 NM N OF THE AXIS. A SURFACE TROUGH EXTENDS FROM THE
TAIL END OF THE SHEAR LINE NEAR 14N75W TO THE COLOMBIA/PANAMA
BORDER NEAR 7N77W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 60 NM E
OF THE AXIS. A SECOND SURFACE TROUGH IS JUST W OF THE SRN
WINDWARD ISLANDS ALONG 12N62W TO 6N65W COINCIDING WITH A SMALL
MOISTURE MAXIMUM THAT TRACKED WWD FROM THE TROPICAL ATLC.
POSSIBLE ISOLATED SHOWERS ARE WITHIN 30 NM OF THE AXIS.
ALOFT...AN UPPER LEVEL RIDGE COVERS THE ERN CARIBBEAN CENTERED E
OF NRN BRAZIL. EXPECT POSSIBLE SHOWER ACTIVITY TO CONTINUE
ACROSS THE CENTRAL CARIBBEAN AS ENHANCED MOISTURE STAYS ACROSS
THAT PORTION OF THE BASIN.

ATLANTIC OCEAN...
SURFACE RIDGING COVERS THE FAR W ATLC ANCHORED BY A 1020 MB HIGH
OFF THE COAST OF CAPE CANAVERAL FLORIDA NEAR 29N79W MAINTAINING
FAIR CONDITIONS ACROSS THE AREA. A BROAD UPPER LEVEL TROUGH
CENTERED N OF NEW HAMPSHIRE IS SUPPORTING A COLD FRONT THAT
ENTERS THE DISCUSSION AREA NEAR 32N47W ALONG 27N50W 21N56W TO
THE NRN LEEWARD ISLANDS NEAR 18N62W. SCATTERED SHOWERS ARE
WITHIN 250 NM E OF THE AXIS N OF 23N. ISOLATED SHOWERS ARE
WITHIN 60 NM SE OF THE AXIS ELSEWHERE. A SURFACE TROUGH IS E OF
THE LESSER ANTILLES AND AHEAD OF THE FRONT ALONG 21N55W TO
13N59W SUPPORTING SCATTERED SHOWERS WITHIN 45 NM E OF THE AXIS.
FARTHER S...A SHEAR LINE IS N OF THE ITCZ AXIS ALONG 8N32W
10N43W 6N53W SUPPORTING SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS
WITHIN 75 NM EITHER SIDE OF THE AXIS. TO THE N...ANOTHER SURFACE
RIDGE DOMINATES ANCHORED BY A 1018 MB HIGH NEAR 25N42W. THE
SURFACE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE EXTENDING
FROM NRN BRAZIL ALONG 40W. ACROSS THE ERN ATLC...AN UPPER LEVEL
TROUGH EXTENDS FROM THE AZORES ISLANDS TO S OF THE CAPE VERDE
ISLANDS SUPPORTING A LOW PRESSURE SYSTEM CENTERED NW OF THE
CANARY ISLANDS NEAR 32N23W WITH A COLD FRONT ENTERING THE
DISCUSSION AREA NEAR 32N20W ALONG 26N20W 22N28W 22N33W.
SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS ARE WITHIN 60 NM EITHER
SIDE OF THE AXIS. A SURFACE TROUGH IS BEHIND THE FRONT EXTENDING
FROM THE LOW CENTER ALONG 29N25W 26N31W. NO SHOWERS ARE
ASSOCIATED WITH THE TROUGH.

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

$$
WALTON





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