[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 101818 CCA
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT THU AUG 10 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 41W SOUTH OF 20N MOVING
WEST NEAR 15 KT. CYCLONIC CURVATURE WITH AN INVERTED V PATTERN
IS MAINLY NOTED IN THE LOW CLOUD MOTIONS N OF 10N BETWEEN 35W
AND 48W. OVERALL THERE IS LITTLE SIGNIFICANT CONVECTION
ASSOCIATED WITH THIS WAVE. A CLUSTER OF MODERATE CONVECTION THAT
WAS NOTED W OF THE AXIS NEAR 9N45W THIS MORNING HAS SINCE
DIMINISHED IN COVERAGE AND INTENSITY. ONLY ISOLATED SHOWERS AND
THUNDERSTORMS ARE NOTED AS OF 1700 UTC WITHIN 200NM OF EITHER
SIDE OF THE AXIS.

AN EASTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 63W S OF 21N
MOVING W NEAR 20 KT. SHOWER AND THUNDERSTORM ACTIVITY ASSOCIATED
WITH THIS WAVE REMAINS DISORGANIZED...AND THE AIR FORCE
RECONNAISSANCE MISSION FOR TODAY HAS BEEN CANCELLED. UPPER-LEVEL
WINDS ARE NO LONGER FAVORABLE FOR TROPICAL CYCLONE FORMATION AND
NO SIGNIFICANT DEVELOPMENT OF THIS SYSTEM IS EXPECTED AS IT
MOVES WESTWARD ACROSS THE CARIBBEAN SEA NEAR 20 KT.  THIS
MORNINGS QUIKSCAT PASS DID NOT SHOW A CLOSED LOW AND LOW CLOUD
MOTIONS DO NOT SUGGEST A SURFACE LOW IS PRESENT. THUS...THE LOW
THAT WAS PREVIOUSLY ALONG THIS WAVE HAS BEEN REMOVED. ISOLATED
MODERATE CONVECTION ASSOCIATED WITH THIS WAVE IS NOTED WITHIN
300NM OF EITHER SIDE OF THE AXIS. CLOUD TOPS ASSOCIATED WITH THE
CLUSTER OF MODERATE TO STRONG CONVECTION THAT DEVELOPED JUST
SOUTH OF THE LEEWARD ISLANDS THIS MORNING HAVE WARMED THIS
AFTERNOON.

A TROPICAL WAVE EXTENDING THROUGH THE BAY OF CAMPECHE...SRN
MEXICO..AND INTO THE GULF OF TEHUANTEPEC IS PRODUCING MINIMAL
SHOWER ACTIVITY IN THE SW GULF OF MEXICO. THE SCATTERED SHOWERS
AND TSTMS NORTH OF THE WAVE MOVING INTO THE WRN GULF FROM 22N TO
29N BETWEEN 90W AND 97W SEEM MORE ASSOCIATED WITH INSTABILITY
AROUND THE BASE OF THE THE UPPER TROUGH IN THE VICINITY.

...THE ITCZ...
ITCZ IS CENTERED ALONG 12N15W 11N39W 11N43W TO THE SOUTH
AMERICAN COAST NEAR 10N62W. SCATTERED SHOWERS AND TSTMS WITH
EMBEDDED ISOLATED MODERATE CONVECTION LIES MAINLY S OF THE AXIS
FROM 4N TO 11N BETWEEN THE AFRICAN COAST AND 43W. SCATTERED
SHOWERS AND TSTMS ALSO EXIST FROM 7N TO 13N BETWEEN 43W AND THE
VENEZUELAN COAST...WITH THE STRONGEST CLUSTER OF MODERATE
CONVECTION IN THIS REGION NOTED NEAR 10N53W.

...DISCUSSION...
THE GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL LOW CENTER IS SEEN IN WV IMAGERY MOVING
FROM THE CENTRAL TO WESTERN GULF. THIS IS PRODUCING CYCLONIC
FLOW OVER MUCH OF THE GULF. SCATTERED SHOWERS AND TSTMS NEAR THE
BASE OF THE UPPER LOW ARE MOVING INTO THE WRN GULF FROM 22N TO
29N BETWEEN 90W AND 97W. ISOLATED SHOWERS ARE ALSO NOTED WEST OF
SW FLORIDA THROUGH 88W. FAIRLY LIGHT E/SE WINDS AT THE SURFACE
CONTINUE IN THE GULF THIS AFTERNOON ON THE W/SW PORTION OF HIGH
PRESSURE EXTENDING FROM THE ATLC. THE EXCEPTION IS THE NE GULF
WHERE LIGHT/VARIABLE TO LIGHT WSW WINDS DOMINATE...JUST N OR IN
THE VICINITY OF THE RIDGE AXIS. SIMILAR CONDITIONS EXPECTED THE
NEXT COUPLE OF DAYS...THOUGH SHOWER ACTIVITY ASSOCIATED WITH THE
UPPER LOW WILL MOVE TOWARDS AND INTO SRN TEXAS AND NE MEXICO.

THE CARIBBEAN SEA...
PARTS OF THE NORTHWESTERN CARIBBEAN SEA AND THE YUCATAN PENINSULA
ARE COVERED BY MIDDLE TO UPPER LEVEL CYCLONIC FLOW FROM THE
CENTRAL GULF OF MEXICO LOW CENTER. A VAGUE UPPER HIGH IS LOCATED
OVER NE NICARAGUA. THIS IS LIKELY AIDING THE SCATTERED MODERATE
CONVECTION MOVING THROUGH CENTRAL AMERICA AND THE SW CARIBBEAN.
THIS ACTIVITY HAS BEEN SURGING WESTWARD OVER THE LAST COUPLE OF
DAYS WITHIN EASTERLY FLOW. HOWEVER THERE IS NO CURVATURE
ASSOCIATED WITH THIS SURGE AND THUS DO NOT THINK THERE IS A
TROPICAL WAVE EMBEDDED. UPPER LEVEL ANTICYCLONIC NE/E FLOW
DOMINATES MUCH OF THE CARIBBEAN E OF 80W. THE EXCEPTION IS THE
AREA JUST S OF THE LEEWARD ISLANDS WHICH IS ON THE SRN PORTION
OF AN ATLC UPPER TROUGH. UPPER WSW FLOW IN THIS AREA IS SHEARING
THE TSTMS ASSOCIATED WITH THE ERN CARIBBEAN TROPICAL WAVE ALONG
63W. 15 TO 25 KT EASTERLY TRADE FLOW CONTINUES TO DOMINATE MUCH
OF THE CARIBBEAN THIS AFTERNOON...DUE TO THE INTERACTION BETWEEN
THE ATLC HIGH NORTH OF THE AREA WITH THE COLOMBIAN LOW. THE
STRONGEST WINDS ARE LOCATED BETWEEN THE COLOMBIAN/VENEZUELAN
COASTS AND PUERTO RICO/HISPANIOLA DUE TO THIS INTERACTION AND
PERHAPS SOME ENHANCEMENT BY THE APPROACHING TROPICAL WAVE.

THE ATLANTIC OCEAN...
AN UPPER LEVEL HIGH OVER THE SE US IS PRODUCING NE FLOW IN THE
SW ATLC OFF THE COAST OF FLORIDA. THESE WINDS ARE BLOWING THE
HIGH CLOUDS OFF THE SCATTERED SHOWERS AND THUNDERSTORMS
OCCURRING MAINLY SOUTH OF A STATIONARY FRONT EXTENDING EAST FROM
THE CAROLINAS. A FAIRLY DRY UPPER LEVEL LOW IS SEEN SPINNING
NORTH OF THE LEEWARD ISLANDS...WITH ITS CENTER NEAR 21N63W.
LARGE SCALE UPPER RIDGING DOMINATES MUCH OF THE REMAINDER OF THE
TROPICAL ATLC...WITH THE RIDGE EXTENDING W FROM AFRICA TO NEAR
55W...WITH THE AXIS MORE OR LESS ALONG 20N. FAIR WEATHER WITH
MINIMAL SHOWER ACTIVITY DOMINATES THIS AREA OUTSIDE OF THE
ITCZ/TROPICAL WAVE VICINITY. SURFACE HIGH PRESSURE CENTERS ARE
ANALYZED AT 1022MB NEAR 27N32W AND 1020MB NEAR 27N54W...WITH THE
RIDGE AXIS EXTENDING W THROUGH SOUTH CENTRAL FLORIDA.

$$
WILLIS




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