[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 260549
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT WED JUL 26 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0530 UTC.

...SPECIAL FEATURE...

A 1009 MB SURFACE LOW PRESSURE CENTER IS JUST INLAND OVER SOUTH
TEXAS NEAR 27.5N 97.5W MOVING NORTHWARD ABOUT 10 KT.  THIS
SYSTEM IS GENERATING A LARGE AREA OF SHOWERS...THUNDERSTORMS AND
STRONG GUSTY WINDS IN SQUALLS OVER PARTS OF THE WESTERN GULF OF
MEXICO AND THE ADJACENT COASTAL AREAS.  SCATTERED MODERATE
CONVECTION EXISTS FROM 25N-29N BETWEEN 90W-98W. A FEW BUOYS
OFFSHORE INDICATE WINDS NEAR 25 KT..ESPECIALLY IN CONVECTION.
SINCE THE SURFACE LOW CENTER IS OVER LAND...TROPICAL CYCLONE
DEVELOPMENT IS UNLIKELY AT THIS TIME.  HOWEVER...IF THE CENTER
EMERGES OR REFORMS OFFSHORE A TROPICAL DEPRESSION COULD DEVELOP.
REGARDLESS IF THAT OCCURS...LOCALLY HEAVY RAINFALL WILL CONTINUE
TO OCCUR OVER PORTIONS OF EXTREME NORTHEASTERN MEXICO...SOUTHERN
TEXAS...AND SOUTHERN LOUISIANA DURING THE NEXT COUPLE OF DAYS.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 27W S OF 21N MOVING WEST 15-20 KT.
THIS WAVE DOES HAVE SOME LOW-MID LEVEL CURVATURE ESPECIALLY
SOUTH OF 13N EVIDENT ON NIGHT CHANNEL VIS IMAGES. THE WAVE IS
AN AREA OF THICK SAHARAN DUST THAT IS SUPPRESSING ANY AREAS OF
SIGNIFICANT CONVECTION. ISOLATED MODERATE CONVECTION IS EMBEDDED
IN THE ITCZ AND WILL BE DISCUSSED IN THAT SECTION.

TROPICAL WAVE IS ALONG 55W S OF 22N MOVING WEST NEAR 15-20 KT.
THE AREA OF LOW PRES THAT HAS BEEN ALONG THE WAVE OVER THE PAST
FEW DAYS IS NO LONGER EVIDENT IN SATELLITE IMAGERY AND THE
AVAILABLE DATA. HOWEVER...THE WAVE STILL REMAINS WELL-DEFINED
WITH A TITLED INVERTED V-SHAPE EVIDENT. SHOWER ACTIVITY HAS ALSO
INCREASED SLIGHTLY WITH SCATTERED SHOWERS AND ISOLATED TSTMS
WITHIN 120 NM OF THE WAVE AXIS.

TROPICAL WAVE IS ALONG 76W S OF 18N MOVING WEST NEAR 15 KT. THIS
WAVE REMAINS WEAK AND DIFFICULT TO IDENTITY. THE POSITION IS
BASED UPON CONTINUITY OF FORWARD SPEED OVER THE PAST 12-24 HOURS.
LITTLE CONVECTION IS ASSOCIATED WITH THIS FEATURE.

TROPICAL WAVE IS ALONG 87W/88W S OF 17N MOVING WEST NEAR 15 KT.
THIS WAVE SHOWS VERY LITTLE SIGNATURE ON SATELLITE IMAGERY.
HOWEVER IT MAY BE ENHANCING CONVECTION IN THE ITCZ OVER COSTA
RICA SPREADING INTO THE EAST PACIFIC.

...ITCZ...
ITCZ IS CENTERED ALONG 12N17W 11N29W 7N45W TO INLAND OVER SOUTH
AMERICA NEAR 10N60W TO PANAMA NEAR 9N79W. SMALL PATCHES OF
SCATTERED MODERATE CONVECTION IS INLAND OVER AFRICA OUT TO ABOUT
25W LIKELY ENHANCED BY THE TROPICAL WAVE ALONG 27W. SIMILAR
CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN
30W-52W. CLUSTERS OF SCATTERED MODERATE CONVECTION IS OVER E
VENEZUELA FROM 5N-8N BETWEEN 60W-63W AND OVER W COLOMBIA FROM
3N-9N BETWEEN 76W-78W.

...DISCUSSION...
GULF OF MEXICO...
THE MOST ACTIVE WEATHER IN THE REGION IS IN THE WEST GULF
ASSOCIATED WITH A 1009 MB LOW JUST INLAND OVER SOUTH TEXAS. LOW
LEVEL CONVERGENCE AND UPPER DIFFLUENCE IS PRODUCING SCATTERED
MODERATE CONVECTION FROM 25N-29N BETWEEN 90W-98W. FOR MORE
DETAILS SEE THE SPECIAL FEATURE SECTION ABOVE. AN ELONGATED
UPPER LEVEL HIGH IS CENTERED IN THE EASTERN GULF NEAR 27N87W.
DEBRIS MOISTURE IS STREAMING ANTICYCLONICALLY AROUND THE UPPER
HIGH FROM THE CONVECTION IN THE W GULF ACROSS THE SE U.S. AND
THEN SOUTHWARD ACROSS THE W ATLC AND FLORIDA. PATCHES OF
SCATTERED SHOWERS AND TSTMS HAVE DEVELOPED ON THE SOUTHWARD
MOVING BRANCH OF THE ANTICYCLONE. MUCH OF THIS ACTIVITY IS VERY
SCATTERED. ONE SMALL PATCH OF MODERATE CONVECTION IS OFF THE SW
FLORIDA COAST FROM 24N-25N BETWEEN 82W-84W. AT THE
SURFACE...HIGH PRES RIDGING HAS BUILT ACROSS THE AREA FROM THE
CENTRAL ATLC TO A 1020 MB HIGH IN THE E GULF NEAR 28N85W.  A
WEDGE OF DRY UPPER LEVEL AIR IS IN THE CENTRAL GULF BETWEEN
85W-89W KEEPING SKIES MAINLY FAIR. SURFACE WINDS ARE FAIRLY
LIGHT E OF 89W. W OF 89W...WINDS ARE STRONGER WITH A FEW BUOYS
REPORTING 25 KT IN THE NW GULF ESPECIALLY IN AREAS OF
CONVECTION. SIMILAR CONDITIONS ARE EXPECTED ON WED.

CARIBBEAN SEA...
TWO WEAK ILL-DEFINED TROPICAL WAVES ARE IN THE CARIBBEAN SEA.
BOTH OF THESE WAVES ARE RATHER BENIGN ONLY ENHANCING SHOWER
ACTIVITY IN THE ITCZ. SMALL PATCHES OF SHOWERS AND TSTMS ARE
MOVING SWWARD FROM THE STRAITS OF FLORIDA TO THE YUCATAN
CHANNEL. THESE SHOWERS ARE MOVING ANTICYCLONICALLY AROUND AN
UPPER HIGH IN THE E GULF. A SMALL UPPER LOW IS JUST SOUTH OF
CENTRAL CUBA WITH AN UPPER TROUGH AXIS EXTENDING TO HONDURAS.
UPPER LEVEL SOUTHERLY ON THE E SIDE OF THE UPPER LOW IS
PRODUCING BROKEN CLOUDINESS AND ISOLATED SHOWERS OVER JAMAICA
AND HISPANIOLA. AN UPPER RIDGE COVERS THE AREA E OF 68W WITH
PLENTY OF SUBSIDENCE. A WELL-DEFINED TROPICAL WAVE IS
APPROACHING THE AREA ALREADY ENHANCING SCATTERED SHOWERS AND
TSTMS ACROSS THE WINDWARD ISLANDS. THIS WAVE WILL BE MOVING INTO
THE LESSER ANTILLES LATER WED AND TO PUERTO RICO AND HISPANIOLA
ON THU INCREASING THE CHANCE OF RAIN AS IT APPROACHES.  TRADE
WINDS HAVE DECREASED FROM GALE FORCE EARLIER THIS WEEK TO MORE
MODERATE TONIGHT AND THESE WINDS WILL LIKELY REMAIN THAT WAY FOR
THE NEXT DAY OR TWO.

ATLANTIC OCEAN...
THE MAIN SURFACE FEATURE IN THE ATLC IS A DOMINATING BERMUDA
RIDGE WITH A 1027 MB HIGH CENTER NEAR 37N52W AND A 1028 MB HIGH
NEAR 36N44W. BESIDES FOR THE TROPICAL WAVES...THERE ARE ONLY A
FEW AREAS OF SOME WEATHER IN THE ATLC MAINLY CONTRIBUTED TO
UPPER LEVEL FEATURES. A FEW PATCHES OF SHOWERS AND TSTMS ARE IN
THE W ATLC OFF THE NE COAST OF FLORIDA MOVING AROUND THE
PERIPHERY OF AN UPPER RIDGE IN THE E GULF. TWO UPPER LOW'S ONE
NEAR 29N64W AND THE OTHER NEAR 28N55W ARE RATHER DRY FEATURES
ONLY PRODUCING SCATTERED BROKEN CLOUDS AND ISOLATED SHOWERS ON
THE S AND E SIDE OF THEIR CIRCULATION.  THE REMAINDER OF THE
AREA IS ON THE SOUTH SIDE OF AN AMPLIFIED UPPER RIDGE/TROUGH
PATTERN WITH THE RIDGE AXIS ALONG 45W AND THE BASE OF THE UPPER
TROUGH DIGGING TO NEAR 32N20W. THE UW-CIMSS SAHARAN AIR LAYER
ANALYSIS FROM 03 UTC DEPICTS THAT THE LEADING EDGE OF THICK DUST
IS BEHIND THE WELL DEFINED TROPICAL WAVE APPROACHING THE
CARIBBEAN...E OF 55W FROM 10N-30N. SCATTERED MORE MODERATE DUST
HAS SPREAD ACROSS THE ENTIRE CARIBBEAN.

$$
CANGIALOSI


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