[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 280557
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI JUL 28 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0530 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 30W SOUTH OF 17N MOVING WEST 15-20 KT.
THIS WAVE HAS A FAIR AMOUNT OF BROAD LOW-MID LEVEL CURVATURE
ASSOCIATED WITH IT. CONVERGENCE IS THE STRONGEST AHEAD OF THE
WAVE AXIS EMBEDDED IN THE ITCZ WHERE THERE IS SCATTERED MODERATE
CONVECTION FROM 6N-11N BETWEEN 32W-38W.

A TROPICAL WAVE IS ALONG 52W SOUTH OF 22N MOVING WEST NEAR 20
KT. THIS WAVE IS NOT AS HIGH AMPLITUDE OR WELL STRUCTURED TODAY
THAN IT WAS OVER THE PAST FEW DAYS. HOWEVER...IT IS STILL RATHER
EASY TO LOCATE WITH BROAD LOW LEVEL TURING EVIDENT ON SATELLITE
IMAGERY. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THIS
WAVE. ISOLATED SHOWERS AND TSTMS ARE WITHIN 300 NM EITHER SIDE
OF THE AXIS.

A TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 70W/71W SOUTH
OF 23N MOVING WEST NEAR 15 KT. THIS WAVE INTERACTING WITH AN
UPPER TROUGH ACROSS THE BAHAMAS IS PRODUCING PATCHES OF
SCATTERED MODERATE CONVECTION WITHIN 240 NM EITHER SIDE OF THE
ANALYZED WAVE AXIS. BASED UPON THE LATEST APPEARANCE ON
SATELLITE IMAGERY...THE AXIS MAY BE ADJUSTED SLIGHTLY AHEAD ON
THE 06Z SURFACE ANALYSIS. WESTERLY UPPER LEVEL WINDS ARE
SHEARING THE TSTMS TO THE EAST OF THE WAVE AXIS. THESE UPPER
WINDS ARE UNFAVORABLE FOR FURTHER DEVELOPMENT.

A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 87W/88W SOUTH OF
19N MOVING WEST 15 KT. THIS WAVE AXIS IS ALONG THE LEADING EDGE
OF A SURGE OF LOW-MID LEVEL CLOUDS WITH EMBEDDED
ISOLATED/SCATTERED SHOWERS AND TSTMS. THIS WAVE REMAINS WEAK
AND IS ENTERING THE EAST PACIFIC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 17N16W 11N28W 10N40W TO INLAND OVER
SOUTH AMERICA NEAR 9N61W TO COSTA RICA NEAR 10N83W. BESIDES FOR
THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVES...A
CLUSTER OF MODERATE CONVECTION IS MOVING OFF THE COAST OF AFRICA
E OF 18W FROM 14N-19N. SCATTERED MODERATE CONVECTION IS ACROSS
SOUTH AMERICA ENHANCED BY THE CENTRAL CARIBBEAN WAVE FROM 1N-8N
BETWEEN 57W-76W.

...DISCUSSION...
GULF OF MEXICO...
RELATIVELY QUIET WEATHER EXISTS ACROSS THE GULF OF MEXICO THIS
EARLY MORNING. AN UPPER HIGH IS CENTERED TO THE NORTH OF THE
AREA OVER THE SE U.S. A NARROW UPPER TROUGH OFF THE E COAST OF
THE U.S. DIGS TO CENTRAL FLORIDA WHERE AN UPPER LOW APPEARS TO
BE FORMING. UNLIKE THE PAST FEW NIGHTS...UPPER DIFFLUENCE IS
RATHER WEAK ACROSS MUCH OF THE AREA ONLY PRODUCING SCATTERED
SHOWERS IN THE E GULF AND FLORIDA AND ISOLATED SHOWERS IN THE
CENTRAL AND WESTERN GULF. AT THE SURFACE...RIDGING IS LOCKED IN
EXTENDING FROM THE BERMUDA-AZORES HIGH. SFC FLOW IS GENERALLY
E-SELY AT 10-15 KT. TROPICAL MOISTURE ASSOCIATED WITH THE
CENTRAL CARIBBEAN WAVE WILL BE ENTERING THE AREA THIS WEEKEND
POSSIBLY INCREASING THE CHANCE OF PRECIP IN THE SOUTHERN GULF.
HOWEVER...MODELS SUGGEST THAT THE WAVE WILL BEGIN TO LOSE SOME
OF ITS MOISTURE AS IT HEADS WWD. OTHERWISE...LITTLE CHANGE IS
EXPECTED THIS WEEKEND AS SFC RIDGING REMAINS ESTABLISHED.

CARIBBEAN SEA...
THE MAIN FEATURE IN THE REGION IS A TROPICAL WAVE IN THE CENTRAL
CARIBBEAN. THIS WAVE IS INTERACTING WITH AN UPPER TROUGH ACROSS
THE BAHAMAS TO GENERATE A WIDE AREA OF SCATTERED MODERATE
CONVECTION ACROSS SOUTH AMERICA AND THE CENTRAL CARIBBEAN FROM
9N-18N BETWEEN 67W-75W. THE STRONGEST CONVECTION IS 150 NM SOUTH
OF HISPANIOLA FROM 14N-16N BETWEEN 70W-74W. IN THE UPPER
LEVELS...A SMALL UPPER LOW CONTINUES TO DIVE SWWD NOW OVER THE
YUCATAN PENINSULA. AN UPPER RIDGE COVERS MUCH OF THE REMAINDER
OF THE AREA. BESIDES FOR THE CONVECTIVE ACTIVITY ASSOCIATED WITH
THE TROPICAL WAVE...ONLY SCATTERED SHOWERS DOT THE CARIBBEAN.
TRADE WINDS ARE 10 TO 20 KT ACROSS THE CARIBBEAN...THESE WINDS
WILL REMAIN IN THAT RANGE...POSSIBLY SLACKENING A BIT...THRU THE
WEEKEND. MOISTURE WILL BE ON THE INCREASE ACROSS THE LESSER
ANTILLES TODAY AND SAT AS ANOTHER TROPICAL WAVE APPROACHES THE
AREA...HOWEVER THIS WAVE DOES NOT APPEAR THAT IT WILL BE AS
CONVECTIVELY ACTIVE AS THE WAVE CURRENTLY IN THE CARIBBEAN.

ATLANTIC OCEAN...
THE DOMINANT FEATURE IN THE ATLC IS THE BERMUDA-AZORES RIDGE
WITH THE SFC RIDGE AXIS EXTENDING FROM A 1027 MB HIGH OVER THE
AZORES TO A 1029 MB HIGH NEAR 33N52W ACROSS THE N CENTRAL GULF.
SCATTERED PATCHES OF MOISTURE DRIVEN BY MODERATE E WINDS IS THE
THEME ACROSS THE ATLC N OF THE TROPICAL WAVES. IN THE UPPER
LEVELS...A MID-UPPER LEVEL NARROW TROUGH LIES OFF THE E COAST OF
THE U.S. PRODUCING A NARROW PLUME OF HIGH LEVEL MOISTURE W OF
75W. AN UPPER LOW IS N OF THE BAHAMAS NEAR 27N71W INCREASING
SHOWER ACTIVITY IN THE CARIBBEAN AS IT INTERACTS WITH THE
TROPICAL WAVE. SEE THE CARIBBEAN SECTION FOR MORE DETAILS. THE
REMAINDER OF ATLC IS DOMINATED BY A LARGE UPPER RIDGE EXTENDING
FROM AFRICA TO 65W. UPPER DIFFLUENCE BETWEEN THIS RIDGE AND
TROUGH N OF THE BAHAMAS IS PRODUCING AN AREA OF UPPER LEVEL
MOISTURE BETWEEN 61W-73W. MODERATE TO STRONG SUBSIDENCE LIES
EAST OF 63W N OF 20N...THIS DRY STABLE AIR IS SUPPRESSING ANY
CONVECTION FROM FORMING IN THIS REGION.

$$
CANGIALOSI


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