[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131709
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT THU JUL 13 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
1700 UTC.

...TROPICAL WAVES...
A WELL-DEFINED TROPICAL WAVE IS ALONG 25W SOUTH OF 16N MOVING
WEST 15-20 KT. LOW-MID LEVEL CYCLONIC TURNING IS CLEARLY EVIDENT
ON VISIBLE SATELLITE IMAGERY. SCATTERED SHOWERS AND ISOLATED
TSTMS ARE WITHIN 180 NM EITHER SIDE OF THE WAVE AXIS.

A TROPICAL WAVE IS ALONG 48W SOUTH OF 14N MOVING WEST NEAR 15
KT. THIS WAVE IS NOT VERY WELL DEFINED AT THIS TIME. LITTLE
SHOWER ACTIVITY IS DIRECTLY ASSOCIATED WITH THIS FEATURE.

A TROPICAL WAVE HAS MOVED INTO THE EASTERN CARIBBEAN ALONG 64W
SOUTH OF 22N MOVING WEST NEAR 15 KT. THIS WAVE REMAINS EASY TO
LOCATE. THE VORTICITY MAXIMUM OR ILL-DEFINED SFC LOW THAT WAS
ALONG THE WAVE YESTERDAY HAS DISSIPATED OVERNIGHT BUT A NEW
SMALL BURST OF CONVECTION HAS DEVELOPED FROM 12N-14N BETWEEN
63W-65W TODAY. DESPITE THE FAIR WAVE SIGNATURE...FURTHER
DEVELOPMENT IS NOT EXPECTED AT THIS TIME DUE TO UNFAVORABLE
UPPER LEVEL WINDS. SCATTERED SHOWERS AND ISOLATED TSTMS ARE
WITHIN 300 NM BEHIND THE WAVE AXIS. AN EARLIER QUIKSCAT PASS
SHOWS AN INCREASE IN THE WINDS BEHIND THE AXIS ESPECIALLY IN THE
CONVECTION.

A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 84W SOUTH OF 17N
MOVING WEST 10 TO 15 KT. LITTLE SIGNATURE IS EVIDENT ON VISIBLE
SATELLITE IMAGERY. HOWEVER...THIS WAVE MAY BE ENHANCING CLUSTERS
OF MODERATE TO STRONG CONVECTION IN THE ITCZ.

...ITCZ...
BESIDES FOR THE CONVECTION ASSOCIATED WITH THE EASTERN ATLANTIC
TROPICAL WAVE...THE ITCZ IS RELATIVELY QUIET WITH ONLY SCATTERED
SHOWERS AND ISOLATED TSTMS WITHIN 240 NM EITHER SIDE OF THE
AXIS.

...DISCUSSION...
GULF OF MEXICO...
A SURFACE TROUGH...THAT WAS IN THE W BAHAMAS AND OVER SOUTH
FLORIDA YESTERDAY HAS TRACKED WESTWARD INTO THE EASTERN GULF OF
MEXICO. AS OF 1500 UTC...THE BOUNDARY LIES ALONG 29N86W 26N83W
23N82W. SCATTERED SHOWERS AND TSTMS ARE WITHIN 90 NM EITHER
SIDE OF THE TROUGH AXIS N OF 26N. DOPPLER RADAR INDICATES A
POSSIBLE SMALL SURFACE LOW DEVELOPING ALONG THE TROUGH NORTHWEST
OF KEY WEST WHERE THERE IS A LARGER AREA OF RAINFALL SOUTH OF
26N...NAMELY WITHIN 180 NM EITHER SIDE OF THE TROUGH AXIS. THE
OTHER FEATURE IN THE GULF...IS A LARGE UPPER LEVEL LOW WHICH IS
NOW CENTERED NEAR 23N94W. UPPER LEVEL DIFFLUENCE IS GENERATING
ISOLATED/SCATTERED SHOWERS ESPECIALLY ON THE MOIST EAST SIDE OF
THE UPPER LEVEL CIRCULATION FROM THE YUCATAN PENINSULA TO THE
CENTRAL AND WESTERN GULF. BOTH THE UPPER LEVEL LOW AND SFC
TROUGH WILL CONTINUE TO TRACK WESTWARD ACROSS THE GULF OF MEXICO
OVER THE NEXT COUPLE OF DAYS. MOISTURE ASSOCIATED WITH THE SFC
TROUGH WILL MOVE INTO THE CENTRAL GULF OF MEXICO TOMORROW
ALLOWING THE EASTERN GULF AND FLORIDA TO CLEAR OUT.

THE CARIBBEAN SEA...
AN UPPER LEVEL TROUGH/RIDGE PATTERN REMAINS IN PLACE ACROSS THE
CARIBBEAN SEA. THE UPPER TROUGH EXTENDS FROM THE BAHAMAS TO THE
SW CARIBBEAN NEAR 12N80W. DRY/STABLE AIR IS ASSOCIATED WITH THE
TROUGH...SINKING SOUTHWESTWARD. WEAK UPPER RIDGING LIES TO THE
EAST OF THE TROUGH WITH THE UPPER AXIS ALONG 68W-70W.  THE MAIN
WEATHER PRODUCING FEATURE IN THE AREA IS A TROPICAL WAVE IN THE
EASTERN CARIBBEAN. SCATTERED SHOWERS AND TSTMS ARE MOSTLY BEHIND
THE WAVE AXIS ACROSS THE LESSER ANTILLES. A SMALL BURST OF
MODERATE CONVECTION DEVELOPED EARLIER TODAY IS CURRENTLY FROM
12N-14N BETWEEN 63W-65W. WHILE DEVELOPMENT DOES NOT APPEAR
LIKELY...THIS WAVE WILL CARRY MOISTURE TO PUERTO RICO AND
HISPANIOLA TONIGHT AND TOMORROW. TRADE WINDS ARE GENERALLY NEAR
20 KT ACROSS THE AREA WITH A SLIGHT INCREASE IN THE WINDS BEHIND
THE WAVE AXIS... ESPECIALLY IN AREAS OF CONVECTION. NUMEROUS
MODERATE TO STRONG CONVECTION...ASSOCIATED WITH THE ITCZ...HAS
MOVED OFF THE COAST OF COLOMBIA AND IS NOW IN THE EAST PACIFIC
BASIN.

THE ATLANTIC OCEAN...
A BROAD BERMUDA-AZORES RIDGE LIES ACROSS THE ENTIRE ATLANTIC
BASIN WITH A COUPLE OF HIGH PRES CENTERS NORTH OF THE DISCUSSION
AREA. THIS HIGH PRES RIDGE IS SUPPLYING PLENTY OF FAIR TRANQUIL
WEATHER ACROSS A LARGE PORTION OF THE ATLANTIC. THE ONLY AREAS
OF UNSETTLED WEATHER IS ASSOCIATED WITH THE TROPICAL WAVES WHICH
ARE DISCUSSED IN THAT SECTION. IN THE UPPER LEVELS...RIDGING IS
MOSTLY THE THEME WITH A BROAD UPPER HIGH CENTERED OFF THE
CAROLINA COASTLINE WITH RIDGING EXTENDING TO 50W. A NARROWER
AMPLIFIED UPPER HIGH IN THE EAST ATLANTIC IS CENTERED NEAR
26N21W WITH RIDGING EXTENDING WESTWARD TO 30W. IN BETWEEN THE
BROAD UPPER RIDGING A NARROW WEAK UPPER TROUGH LIES NORTH OF 27N.
MODERATE TO STRONG SUBSIDENCE COVERS A LARGE PORTION OF THE
BASIN. LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED OVER THE
NEXT COUPLE OF DAYS.

$$
CANGIALOSI


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