[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 220000
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI OCT 21 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...

THE CENTER OF CATEGORY FOUR HURRICANE WILMA IS NEAR 20.6N 86.9W
AT 22/0000Z...MOVING ERRATICALLY TO THE NW 4 KT. THIS POSITION
IS NEAR THE NORTHERN TIP OF COZUMEL ISLAND.  THE ESTIMATED
MINIMUM CENTRAL PRESSURE IS 930 MB. THE MAXIMUM SUSTAINED WIND
SPEEDS ARE 120 KT WITH GUSTS TO 145 KT. SEE LATEST NHC FORECAST/
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/ WTNT24 KNHC AND THE
PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC
FOR MORE DETAILS.  POWERFUL HURRICANE WILMA CONTINUES TO BATTER
THE NE COAST OF YUCATAN WITH THE EYE VERY CLOSE TO THE
MAINLAND.  SATELLITE IMAGES SHOW A CLASSICAL STRONG HURRICANE
SIGNATURE OF A WELL-DEFINED EYE... DEEP TSTMS AROUND THE CENTER
AND RAPIDLY EXPANDING OUTFLOW.  HOW LONG IT SPENDS OVER YUCATAN
IS CRITICAL TO DETERMINING ITS LIKELY FINAL INTENSITY AS IT
APPROACHES THE PENINSULA OF FLORIDA ON MONDAY.  NUMEROUS
MODERATE/ISOLATED STRONG TSTMS WITHIN 100 NM OF THE CENTER WITH
OTHER RAINBANDS SCATTERED OVER WESTERN CUBA.. THE FLORIDA
STRAITS.. AND SOUTHWARD THROUGHOUT THE REST OF YUCATAN INTO
BELIZE.  CLOUD TOPS HAVE BEEN WARMING DURING THE PAST 3 HOURS AS
IT INTERACTS WITH LAND.

E CARIBBEAN TROPICAL WAVE IS ALONG 63W S OF 20N MOVING W 10 KT.
THE SYSTEM CONTINUES TO GET BETTER ORGANIZED WITH BANDS OF
CONVECTION BEGINNING TO WRAP AROUND A DEVELOPING 1009 MB LOW
NEAR 14N64W.  THE UPPER ENVIRONMENT IS FAVORABLE FOR FURTHER
DEVELOPMENT AND THE SYSTEM COULD BECOME A TROPICAL DEPRESSION
DURING THE NEXT 36 HOURS.  STRONG GUSTY WINDS APPROACHING GALE
FORCE ARE NEAR AND NE OF THE LOW ALONG WITH SCATTERED SHOWERS
AND TSTMS THROUGHOUT THE E CARIBBEAN E OF A LINE FROM MARGARITA
ISLAND TO HAITI NOW OVERSPREADING PUERTO RICO.   THE LOW IS
TRACKING GENERALLY WNW AT 10-15 KT AND COULD BE APPROACHING
HISPANIOLA LATE TOMORROW.

...TROPICAL WAVES...

E ATLC  WAVE IS ALONG 36W/37W S OF 16N MOVING W 15 KT.  ANY WAVE
SIGNATURE IS MASKED BY A DEEP UPPER TROUGH NW OF THE WAVE.
HOWEVER THE WAVE CONTINUES TO BE QUITE CONVECTIVELY ACTIVE
THANKS TO UPPER DIFFLUENCE FROM THE WAVE... SUPPORTING SCATTERED
MODERATE CONVECTION FROM 5N-9N BETWEEN 35W-38W.

CENTRAL CARIBBEAN WAVE IS ALONG 71W/72W S OF 19N MOVING W 15
KT.  THE WAVE IS NOT PRODUCING ANY CONVECTION AND ONLY BROAD
CURVATURE IS SEEN ON VISIBLE SATELLITE IMAGES.

W CARIBBEAN WAVE PREVIOUSLY ALONG 81W/82W HAS BEEN DROPPED FROM
THE ANALYSIS.  DEEP LAYERED WESTERLY FLOW CONTINUES TO WEAKEN
THE WAVE AND IT IS NO LONGER TRACEABLE NOR A SIGNIFICANT
FEATURE.

...ITCZ...

ITCZ AXIS IS ALONG 8N13W 7N26W 10N36W 8.5N46W 11N58W.  WIDELY
SCATTERED MODERATE CONVECTION FROM 6N-11N BETWEEN 23W-32W.
SCATTERED MODERATE CONVECTION FROM 5N-8N BETWEEN 34W-46W.

...DISCUSSION...

GULF OF MEXICO...
WILMA IS CREEPING SLOWER TO THE AREA... SPREADING HIGH CLOUDS
AND WIDELY SCATTERED SHOWERS THROUGHOUT THE EASTERN GULF.. WITH
THE RAIN CONFINED S OF 26N E OF 89W.  VERY DRY AIR CONTINUES TO
LIMIT THE WESTWARD EXTENT OF THE CLOUD SHIELD E OF 90W.  COLD
FRONT DROPS FROM LOUISIANA NEAR NEW ORLEANS THRU THE NW GULF
INTO S TEXAS BETWEEN BROWNSVILLE AND CORPUS CHRISTI.  DRIER AIR
LIES BEHIND THE FRONT WITH NO SIGNIFICANT CONVECTION.  THIS
FRONT SHOULD CONTINUE SOUTHWARD AS A BROAD DIFFUSE FEATURE...
EVENTUALLY APPROACHING THE HURRICANE IN A COUPLE DAYS.  PLEASANT
FALL WEATHER IS EXPECTED OVER THE WESTERN GULF COAST WHILE ALL
EYES ARE ON WILMA IN THE FLORIDA PENINSULA.

CARIBBEAN SEA...
BETWEEN WILMA AND THE DISTURBANCE IN THE SE CARIBBEAN... A THIN
VEIL OF HIGH CLOUDS COVERS THE CENTRAL CARIBBEAN ROTATING AROUND
A LARGE UPPER HIGH CENTERED NEAR SE CUBA.  A WEAK 1008 MB IS
NEAR 14N77W... JUST A SWIRL OF LOW CLOUDS.  WLY LOW-LEVEL FLOW
CONTINUES TO FORCE PLENTY OF TSTMS OVER CENTRAL AMERICA S OF
NICARAGUA... WITH THE SEA-BREEZE EVEN ASSISTING STORMS OVER NW
COLOMBIA.  A VERY DIVERGENT PATTERN REMAINS IN PLACE OVER THE SE
CARIBBEAN WITH AN INVERTED TROUGH MOVING ACROSS NW S AMERICA AND
UPPER RIDGING BUILDING IN THE TROPICAL ATLC ALONG 55W.  HEAVY
RAIN AND GUSTY WINDS ARE POSSIBLE IN THE LEEWARD ISLANDS
WESTWARD THRU HISPANIOLA IN THE N CARIBBEAN AS THE DISTURBANCE
PASSES WITH ANOTHER DAY OF UNSETTLED WEATHER LIKELY IN THE
WINDWARDS DUE TO THE LONG FETCH OF MOISTURE BEHIND THE SYSTEM.

ATLANTIC OCEAN...
UPPER RIDGING DOMINATES MOST OF THE SUBTROPICAL ATLC... WITH
RIDGING EXTENDING FROM THE CENTRAL BAHAMAS ENE TO 27N50W THEN
24N30W IN THE E ATLC.   A WEAK UPPER TROUGH BREAKS THE RIDGE
ALONG 61W OTHERWISE THE RIDGE IS SOLID.  UPPER DIFFLUENCE ALONG
THE NORTHERN PORTION OF THE RIDGE ALONG WITH A SURFACE TROUGH
OCCASIONALLY CAUSES A FEW SHOWERS/TSTMS N OF 27N BETWEEN
50W-65W.  OTHERWISE ISOLATED SHOWERS/TSTMS ARE IN THE NW
BAHAMAS... THE EXTREME OUTER FRINGES OF WILMA.  STRONG
SUBSIDENCE CONTROLS THE CENTRAL ATLC BETWEEN 15N-30N FROM
30W-55W WITH LOTS OF CONVERGENCE DUE TO UPPER RIDGING IN THE
SUBTROPICAL ATLC AND BROAD UPPER TROUGHING IN THE TROPICAL ATLC
CENTERED ALONG 38W S OF 17N.  THE UPPER FLOW IS DIVERGENT OVER
THE ITCZ... ASSISTING SHOWER/TSTM DEVELOPING IN THE CENTRAL
ATLC.  WEAK UPPER TROUGHING IS NEAR THE CANARY ISLANDS AND
GENERAL WSW WINDS ALOFT CONTINUE NEAR THE CAPE VERDES AND THE
REST OF THE TROPICAL ATLC... MOSTLY CONVECTION-FREE.  UPPER
RIDGING IS FORECAST TO GROW IN THE WAKE OF THE BROAD TROUGH IN
THE TROPICAL ATLC...AND NE OF THE BAHAMAS.

$$
BLAKE



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