[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221136
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT OCT 22 2011

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...SPECIAL FEATURES...

A BROAD AREA OF LOW PRESSURE COVERS THE SW CARIBBEAN WITH A 1007
MB LOW ANALYZED NEAR 13N81W. LINGERING TROPICAL MOISTURE IS
GENERATING SCATTERED/HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS S
OF 15N W OF 80W TO INLAND OVER NICARAGUA. ALTHOUGH THERE HAS
BEEN LITTLE CHANGE IN THE ORGANIZATION DURING THE PAST SEVERAL
HOURS...SURFACE PRESSURES CONTINUE TO FALL OVER THE AREA AND THE
DEVELOPMENT OF A TROPICAL DEPRESSION IS STILL POSSIBLE OVER THE
NEXT DAY OR TWO. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL
ATLC NEAR 16N17W CONTINUING TO 12N25W. THE ITCZ AXIS CONTINUES
FROM 12N25W TO 7N39W. SCATTERED MODERATE/STRONG CONVECTION IS
FROM 2N TO INLAND OVER SW AFRICA E OF 2W ACROSS THE PRIME
MERIDIAN. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG
CONVECTION ARE FROM 2N-6N BETWEEN 3W-18W INCLUDING THE COAST OF
SW AFRICA AND WITHIN 300 NM S OF THE ITCZ/MONSOON TROUGH BETWEEN
21W-36W. A SURFACE TROUGH IS ANALYZED FROM A 1011 MB LOW NEAR
20N40W SW ALONG 16N43W TO 14N48W. CLUSTERS OF SCATTERED
MODERATE/STRONG CONVECTION ARE WITHIN 90/120 NM OF A LINE FROM
16N36W TO 10N45W. A SECOND SURFACE TROUGH IS ALSO IN THE TROPICS
EXTENDING FROM 12N49W 10N52W TO INLAND OVER SOUTH AMERICA NEAR
7N58W. SMALL CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION
ARE FROM 6N-11N BETWEEN 51W-58W.

...DISCUSSION...

GULF OF MEXICO...
NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE GULF THIS MORNING.
STRONG SUBSIDENCE AND DRY STABLE AIR ALSO DOMINATES THE GULF
WITH SOME LINGERING COLD AIR STRATOCUMULUS CLOUDS ARE OVER THE
FAR S GULF LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR
SKIES AGAIN THIS MORNING. A SURFACE RIDGE COVERS THE GULF AND
THE E CONUS WITH A 1022 MB HIGH ALONG COAST OF LOUISIANA NEAR
29N91W. SURFACE RIDGE WILL CONTINUE TO BUILD ACROSS THE W GULF
THROUGH WED.

CARIBBEAN SEA...
THE PRIMARY CONCERN THIS MORNING CONTINUES TO BE THE SURFACE LOW
IN THE SPECIAL FEATURES SECTION ABOVE. THE BROAD UPPER TROUGH
OVER CENTRAL ATLC EXTENDS OVER THE A MAJOR PORTION OF THE
CARIBBEAN INDUCING AN INVERTED UPPER TROUGH OVER THE NW
CARIBBEAN FROM NE HONDURAS TO JUST W OF THE CAYMAN ISLANDS. THE
REMNANTS OF A STATIONARY FRONTAL BOUNDARY REMAIN ACROSS THE NW
CARIBBEAN EXTENDING OVER CUBA NEAR 21N78W TO OVER THE CAYMAN
ISLANDS TO E OF HONDURAS NEAR 16N82W. LINGERING MOISTURE COUPLED
WITH THE SURFACE AND UPPER LEVEL FEATURES ARE GENERATING HEAVY
SHOWERS AND ISOLATED THUNDERSTORMS N OF 15N BETWEEN 79W-87W. THE
BROAD UPPER TROUGH IS GENERATING CLUSTERS OF SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS OVER THE CENTRAL AND E CARIBBEAN S OF 19N
TO ALONG COAST OF COLOMBIA AND VENEZUELA BETWEEN 65W-80W.
REMNANTS OF THE FRONT WILL MEANDER ACROSS THE NW CARIBBEAN
THROUGH SUN. A TROUGH OVER THE TROPICAL ATLC WILL MOVE W INTO
THE E CARIBBEAN MON REACHING THE CENTRAL CARIBBEAN WED.

ATLANTIC OCEAN...
THE UPPER TROUGH OVER THE E CONUS EXTENDS OVER THE W ATLC W OF
74W SUPPORTING A STATIONARY FRONT THAT EXTENDS THROUGH 32N69W
ALONG 27N72W ACROSS THE BAHAMA ISLANDS NEAR 24N75W TO OVER CUBA
NEAR 21N78W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN
120 NM W OF THE FRONT S OF 30N TO OVER CUBA. COLD AIR
STRATOCUMULUS CLOUDS ARE WITHIN 150 NM W OF THE FRONT. THE
SURFACE RIDGE OVER THE GULF OF MEXICO EXTENDS E TO THE FRONT. A
BROAD UPPER LOW/TROUGH COVERS THE REMAINDER OF THE W ATLC AND
ALL OF THE CENTRAL ATLC CENTERED NEAR 20N64W GENERATING
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 19N-31N BETWEEN
53W-67W. AN UPPER TROUGH EXTENDS S TO OVER THE E ATLC N OF 20N E
OF 30W. A BROAD E/W UPPER RIDGE COVERS THE TROPICAL ATLC S OF
20N E OF 58W PROVIDING DIFFLUENCE BETWEEN THIS UPPER RIDGE AND
THE ABOVE UPPER TROUGH TO GENERATE SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS E OF A LINE FROM 27N21W TO 20N28W TO INLAND OVER
THE WESTERN SAHARA. A BROAD SURFACE RIDGE DOMINATES THE ATLC N
OF 25N E OF THE FRONT TO AFRICA. THE STATIONARY FRONT WILL DRIFT
W THROUGH MON. A COLD FRONT WILL MOVE SE ACROSS THE NW ATLC SUN
NIGHT MERGING WITH THE STATIONARY FRONT MON AND THIS MERGED
FRONT WILL EXTEND FROM BERMUDA TO THE SE BAHAMAS MON NIGHT THEN
MOVE INTO THE CENTRAL ATLC BY EARLY WED.

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

$$
PAW




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