[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181139
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE OCT 18 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
1130 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ANALYZED FROM 16N26W TO 10N31W MOVING W AT
15-20 KT. WAVE WAS RELOCATED BASED ON THE UPPER LEVEL WINDS...
SURFACE OBSERVATIONS...AND SATELLITE IMAGERY. WAVE IS WELL
DEFINED AND IS EMBEDDED WITHIN A MOISTURE SURGE AS DEPICTED ON
THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE REMAINS BENEATH AN
UPPER RIDGE ENHANCING SCATTERED MODERATE/STRONG CONVECTION FROM
13N-17N BETWEEN 20W-30W INCLUDING THE CAPE VERDE ISLANDS.

TROPICAL WAVE IS ANALYZED IN THE CENTRAL TROPICAL ATLC FROM
13N43W TO 7N45W MOVING W NEAR 10 KT. WAVE WAS RELOCATED BASED ON
THE UPPER LEVEL WINDS...SURFACE OBSERVATIONS...AND SATELLITE
IMAGERY. WAVE WELL DEFINED AND IS AT THE LEADING EDGE OF A
MOISTURE SURGE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER
IMAGERY. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE
FROM 7N-10N BETWEEN 42W-47W.

TROPICAL WAVE IS ANALYZED IN THE E CARIBBEAN ALONG 67W/68W S OF
17N MOVING 10-15 KT. WAVE IS WELL DEFINED IN THE UPPER LEVEL
SATELLITE WINDS AND IN THE LOW LEVEL CLOUD PATTERN ON SATELLITE
IMAGERY S OF 16N. ISOLATED SHOWERS ARE S OF 15N TO THE COAST OF
VENEZUELA BETWEEN 65W-70W.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST NEAR
15N17W. THE ITCZ IS DISRUPTED BY THE PRESENCE OF THE TROPICAL
WAVES. SCATTERED MODERATE/STRONG CONVECTION IS FROM 5N-10N
BETWEEN 14W-19W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG
CONVECTION ARE WITHIN 45 NM OF 6N BETWEEN 33W-39W.

...DISCUSSION...

GULF OF MEXICO...
A BROAD AREA OF LOW PRESSURE COVERS MOST OF THE GULF INTO THE NW
CARIBBEAN WITH A 1002 MB LOW CENTERED OFF THE N COAST OF THE
YUCATAN PENINSULA NEAR 23N89W AND A SECOND 1003 MB SURFACE LOW
DEVELOPING TO THE N AT 18/0900 UTC NEAR 26N88W WITH A SURFACE
TROUGH FORMING BETWEEN THE LOWS. SCATTERED/NUMEROUS STRONG
CONVECTION IS FROM 24N-27N BETWEEN 82W-86W WITH SCATTERED TO
HEAVY RAINS COVERING THE REMAINDER OF THE AREA S OF 27N E OF 86W
TO INLAND OVER FLORIDA/CUBA AND THROUGH THE STRAITS OF FLORIDA.
A BROAD UPPER RIDGE COVERS THE GULF ANCHORED JUST N OF THE
YUCATAN CHANNEL. THERE REMAINS A DISTINCT BOUNDARY BETWEEN THE
MOIST TROPICAL AIR TO THE SE AND STRONG SUBSIDENCE/DRY STABLE
AIR TO THE NW THAT EXTENDS FROM CEDAR KEY FLORIDA ALONG 28N86W
23N90W TO TAMPICO MEXICO. THE 1003 MB LOW WILL MOVE N-NE THROUGH
WED WITH THE NEW LOW MOVING INLAND NEAR THE FLORIDA BIG BEND
REGION WED NIGHT. THE NEW LOW WILL DEVELOP A FRONTAL BOUNDARY
ACROSS THE E GULF TONIGHT THROUGH WED NIGHT IN ADVANCE OF A
STRONG COLD FRONT CURRENTLY OVER E TEXAS THAT WILL PUSH INTO THE
NW GULF THIS MORNING. THIS STRONGER FRONT WILL MOVE QUICKLY SE
ACROSS THE AREA TO SE OF THE GULF WED EVENING. HIGH PRESSURE
WILL BUILD OVER THE ENTIRE AREA GULF IN THE WAKE OF THE FRONTS
THROUGH SAT.

CARIBBEAN SEA...
THE UPPER RIDGE ANCHORED JUST N OF THE YUCATAN CHANNEL COVERS
MOST OF THE CARIBBEAN WITH AN E/W UPPER RIDGE OVER THE TROPICAL
ATLC COVERING THE SE CARIBBEAN SE OF A LINE FROM NEAR ANTIGUA
AND BARBUDA IN THE LEEWARD ISLANDS TO THE GUAJIRA PENINSULA OF
COLOMBIA. THE BROAD AREA OF LOW PRESSURE OVER THE SE GULF OF
MEXICO COVERS THE NW CARIBBEAN AND COUPLED WITH THE UPPER RIDGE
OVER THE NW CARIBBEAN IS GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 60/75 NM OF LINE FROM THE YUCATAN CHANNEL
NEAR 22N85W TO OFF THE COAST OF BELIZE NEAR 17N88W. EASTERLY
SURFACE FLOW COMBINED WITH THE EASTERLY FLOW ALOFT OVER THE SW
CARIBBEAN IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
S OF 12N W OF 74W TO OVER COLOMBIA AND CENTRAL AMERICA. BROAD
LOWER PRESSURE OVER THE SE GULF AND NW CARIBBEAN WILL LIFT N-NE
TODAY THROUGH WED NIGHT AS A WEAK PRESSURE PATTERN CONTINUES
OVER MUCH OF THE CARIBBEAN. A WEAK COLD FRONT WILL MOVE INTO THE
NW CARIBBEAN TONIGHT INTO EARLY WED THEN BE ABSORBED BY A
STRONGER COLD FRONT THAT PUSHES INTO THE NW CARIBBEAN WED
EVENING. THIS COLD FRONT WILL REACH FROM CENTRAL CUBA TO NE
HONDURAS BY LATE THU WHERE IT WILL STALL AND BEGIN TO WEAKEN
THROUGH SAT. THE TROPICAL WAVE WILL WEAKEN OVER THE CENTRAL
CARIBBEAN LATE WED NIGHT.

ATLANTIC OCEAN...
AN UPPER RIDGE AXIS EXTENDS FROM THE YUCATAN CHANNEL THROUGH THE
STRAITS OF FLORIDA NEAR 24N80W ALONG 26N62W TO 30N50W PROVIDING
A DIFFLUENT ENVIRONMENT TO ENHANCE SCATTERED SHOWERS AND
POSSIBLE ISOLATED THUNDERSTORMS WITHIN 150 NM OF LINE FROM OVER
FLORIDA NEAR 27N80W ALONG 29N70W TO 32N53W. AN UPPER TROUGH
EXTENDS ACROSS THE CENTRAL ATLC FROM AN UPPER LOW NEAR 30N29W
THROUGH A SECOND UPPER LOW NEAR 20N51W INTO THE W TROPICAL ATLC
TO NEAR 16N57W. THE NORTHERN UPPER LOW IS SUPPORTING A WEAK 1014
MB LOW CENTERED NEAR 31N36W WITH A SURFACE TROUGH EXTENDING S
ALONG 29N35W TO 26N38W WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS FROM 29N-33N BETWEEN 23W-33W. A WEAK SURFACE RIDGE
COVERS MOST OF THE ATLC N OF 20N E OF 80W WITH A WEAKNESS IN THE
VICINITY OF THE ABOVE LOW/TROUGH. A BROAD UPPER RIDGE EXTENDS
E/W ACROSS THE TROPICAL ATLC. SURFACE RIDGE OVER THE W ATLC WILL
SHIFT E AND WEAKEN THROUGH EARLY WED. THE BROAD LOW PRESSURE
OVER THE GULF OF MEXICO/NW CARIBBEAN WILL TRACK N-NE THROUGH WED
AHEAD OF A STRONG COLD FRONT THAT WILL MOVE OFF THE NE FLORIDA
COAST WED EVENING. THE FRONT WILL REACH FROM 31N74W TO CENTRAL
CUBA BY EARLY THU THEN WEAKEN AND BECOME STATIONARY FROM NEAR
31N70W TO CENTRAL CUBA FRI AND SAT. WEAK HIGH PRESSURE WILL
BUILD ACROSS THE AREA BEHIND THE FRONT.

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

$$
PAW




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