[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 241800
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON JUL 24 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
1630 UTC.

...SPECIAL FEATURES...

A SURFACE LOW PRESSURE AREA CENTERED JUST EAST OF LA PESCA
MEXICO IS MOVING NORTH AT 5 TO 10 KT. SHOWER AND THUNDERSTORM
ACTIVITY OVER MUCH OF THE WESTERN GULF OF MEXICO AND BAY OF
CAMPECHE HAS INCREASED AND BECOME A LITTLE BETTER ORGANIZED...
AND NOAA BUOYS IN THE SOUTHWESTERN GULF OF MEXICO HAVE RECORDED
WIND GUSTS OF 40 TO 50 MPH THIS MORNING. UPPER-LEVEL WINDS ARE
EXPECTED TO BECOME A LITTLE MORE FAVORABLE...AND A TROPICAL
DEPRESSION COULD DEVELOP DURING THE NEXT DAY OR SO...IF THE LOW
PRESSURE CENTER REMAINS OFFSHORE. LATEST SATELLITE PICTURES AND
SURFACE DATA SHOW THAT A SURFACE LOW IS FORMING NEAR TAMPICO IN
MEXICO.

...TROPICAL WAVES...

HIGH AMPLITUDE TROPICAL WAVE WITH PRONOUNCED INVERTED V PATTERN
IS ALONG 43/44W S OF 24N MOVING WEST NEAR 15 KT. A 1011 MB LOW
IS ON THE WAVE AXIS NEAR 14N. THIS WAVE AND LOW REMAIN
WELL-DEFINED IN AFTERNOON VISIBLE IMAGERY.  HOWEVER...THIS
FEATURE CONTINUES TO BE VOID OF ANY SIGNIFICANT CONVECTION. A
FEW SHOWERS ARE SPIRALING ON THE NORTHERN AND WESTERN SEMICIRCLE
OF THE SFC LOW AND AT THE BASE OF THE WAVE WITHIN 300 NM EITHER
SIDE OF THE AXIS S OF 10N. THIS CENTRAL ATLC WAVE WILL LIKELY
INCREASE IN FORWARD SPEED OVER THE NEXT COUPLE OF DAYS AS IT
TRACKS UNDER A STRONG LOW-LEVEL RIDGE...BRINGING IT INTO THE
TROPICAL ATLC WATERS TUE NIGHT AND THROUGH THE E CARIBBEAN THU
AND FRI.

TROPICAL WAVE IS ALONG 66/67W S OF 19N MOVING WEST NEAR 15 KT.
THIS WAVE REMAINS WEAK AND LOW AMPLITUDE.  WAVE EMBEDDED
WITHIN AN AREA OF DENSE SAHARAN DUST LIMITING ANY ORGANIZED
SHOWER ACTIVITY.

TROPICAL WAVE IS ALONG 78/79W S OF 21N MOVING WEST 15-20 KT.
THIS WAVE IS ALSO WEAK WITH LITTLE ASSOCIATED CONVECTION.
ONLY A HINT OF SOME EVIDENCE OF A WAVE-LIKE STRUCTURE IS EVIDENT
ON SATELLITE IMAGERY.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 9N9W 14N40W 12N45W TO INLAND OVER
SOUTH AMERICA NEAR 8N65W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION EXISTS ALONG THE ITCZ NEAR COASTAL LIBERIA AND SIERRA
LEONE BETWEEN 6-11N. THE ITCZ BETWEEN 21-40W IS RELATIVELY QUIET
WITH ONLY FEW SHOWERS/TSTMS EVIDENT. SCATTERED MODERATE
CONVECTIONS EXISTS ALONG TH ITCZ BETWEEN 50W/64W.

...DISCUSSION...
GULF OF MEXICO...
QUASI STATIONARY UPPER TROF STILL LIES IN THE SE GOMEX THIS
AFTERNOON NEAR 25N85W. A WEAK UPPER RIDGE EXTENDS EAST OF THIS
REGION THROUGH THE FLORIDA PENINSULA AND INTO THE ADJACENT
ATLANTIC/BAHAMA WATERS. IN THE WESTERN GULF...UPPER RIDGE
CONTINUES TO EXTEND EAST FROM INLAND S MEXICO AND INTO THE BAY
OF CAMPECHE. NORTH OF THIS REGION UPPER SW FLOW FOLLOWS THE
SOUTHERN PERIPHERY OF THE ELONGATED TROF STRETCHING FROM THE MID
ATLANTIC REGION TO THE NW GULF. ASSOCIATED UPPER DIFFLUENCE AND
MOISTURE BETWEEN THESE FEATURES IS YIELDING NUMEROUS
MODERATE/SCATTERED STRONG CONVECTION IN THE SW GULF BETWEEN
18N-26N AND 91W-97W. AT THE SURFACE...ANTICYCLONIC FLOW AROUND
THE SW PORTION OF THE BERMUDA HIGH IS CONVERGING WITH FLOW
AROUND A WEAK HIGH OVER THE APPALACHIANS TO PRODUCE A
QUASI-STATIONARY SURFACE FRONTAL BOUNDARY JUST NORTH OF THE GULF
COASTAL REGION. SCATTERED WEAK CONVECTION/ISOLATED MODERATE LIES
IN THE MOIST AIR JUST SOUTH OF THIS BOUNDARY WITHIN 3 DEGREES
FROM A LINE BETWEEN CORPUS CHRISTI TX AND LAKE CITY FL. RADAR
MOSAIC  IMAGERY CONFIRMS NUMEROUS CELLS IN THIS REGION.  SFC
WINDS REMAIN LIGHT IN THE E/SE GULF UNDER WEAK GRADIENT FROM THE
ATLANTIC HIGH INFLUENCE. CENTRAL AND WESTERN GULF SFC FLOW
GENERALLY S/SE 10-20 KT EXCEPT HIGHER UNDERNEATH THE NUMEROUS
SHOWERS AND THUNDERSTORMS PRESENT...AND CONTAIN MORE OF A
WESTERLY COMPONENT NORTH PORTIONS SOUTH OF FRONTAL BOUNDARY.
SIMILAR CONDITIONS EXPECTED THRU 48HRS WITH STRONGEST S/SE FLOW
WESTERN PORTION AS ATLANTIC RIDGE CONTINUES TO INTERACT WITH
LOWER PRESSURE TO THE WEST. SEE SPECIAL FEATURES FOR MORE INFO
ON CONVECTIVE ACTIVITY IN THE SW GULF.

CARIBBEAN SEA...
TWO WEAK LOW AMPLITUDE TROPICAL WAVES EXIST IN THE CARIBBEAN
SEA. BOTH REMAIN BENIGN/DRY FEATURES. FOR MORE DETAILS SEE THE
TROPICAL WAVES SECTION ABOVE. WATER VAPOR SHOWS MOSTLY DRY
MID/UPPER LEVEL AIR IN THE CARIBBEAN FROM 11-19N BETWEEN THE
WINDWARD ISLANDS AND 81W. THIS REGION IS DOMINATED BY AN UPPER
RIDGE TO THE EAST AND TROF TO THE WEST...EXTENDING SOUTH FROM E
CUBA THROUGH HAITI. WEST OF THIS REGION IN THE NW CARIBBEAN LIES
PATCHES OF SCATTERED MODERATE CONVECTION ON THE EAST SIDE OF THE
UPPER RIDGE CENTERED NEAR ACAPULCO MEXICO. MODERATE TO STRONG
TRADE WINDS ARE OCCURRING ACROSS THE CARIBBEAN ON THE SOUTH SIDE
OF THE SUBTROPICAL ATLANTIC RIDGE. A GALE WARNING IS IN EFFECT
BETWEEN 12N-15N AND 73N-77W UNTIL TUESDAY.

ATLANTIC OCEAN...
UPPER RIDGE LIES JUST OFF THE SPACE COAST OF FLORIDA THIS
AFTERNOON...SOUTH OF AN UPPER TROF OVER THE MID ATLANTIC COAST.
MOISTURE ASSOCIATED WITH THESE FEATURES (IN TAFB AREA OF
RESPONSIBILITY) LIES MOSTLY N OF 25N AND W OF 65W. LARGE SCALE
UPPER RIDGING AND LOTS OF DRY AIR CONTINUES TO DOMINATE MUCH OF
THE WEST/CENTRAL ATLANTIC IN THE REGION BETWEEN 40 AND 65W. A
PATCH OF MODERATE CONVECTION LIES ON THE WEST PORTION OF THIS
RIDGING BETWEEN 22N-25N AND 62W-64W. A LARGE UPPER RIDGE EXTENDS
FROM W AFRICA OUT TO 35W. A SMALL UPPER TROF LIES JUST WEST OF
THIS RIDGE...CENTERED NEAR 27N46W. AT THE SURFACE...A 1028MB
HIGH PRESSURE CENTER LIES NEAR 34N53W. MOSTLY FAIR
WEATHER...SCATTERED PATCHES OF LOW TO MID CLOUDS...AND LIMITED
SHOWER ACTIVITY LIE SOUTH OF THIS RIDGE EAST OF 61W. 24/15Z
UW-CIMSS SAHARAN AIR LAYER TRACKING PRODUCT DEPICTS WESTERN
EXTENT OF DENSE DUST OUT TO 42W. THE DUST IS MUCH LESS
PRONOUNCED IN THE VICINITY OF THE STRONG TROPICAL WAVE ALONG
43W-44W...WITH THE CONCENTRATION OF THE DUST INCREASING WEST OF
THIS WAVE THROUGH THE CENTRAL CARIBBEAN NEAR 81W.


$$
WILLIS


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