[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 192339
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED JUL 19 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURE...
TROPICAL STORM BERYL IS CENTERED NEAR 36.3N 73.5W AT 19/2100 UTC
OR ABOUT 135 MILES NORTHEAST OF CAPE HATTERAS NORTH CAROLINA AND
ABOUT 390 MILES SOUTH-SOUTHWEST OF NANTUCKET MASSACHUSETTS.
BERYL IS MOVING TO THE NORTH AT 7 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE HAS DEEPENED SLIGHTLY TO 1002 MB. MAXIMUM SUSTAINED
WIND SPEED HAS INCREASED TO 50 KT WITH GUSTS TO 60 KT. SEE
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. BERYL HAS BEEN BECOMING
BETTER ORGANIZED THROUGHOUT THE DAY. LAST NIGHT THE LOW LEVEL
CENTER WAS PARTIALLY EXPOSED. SINCE THEN...CONVECTION HAS
WRAPPED AROUND THE CENTER AS IT TRACKS OVER THE WARM WATERS OF
THE GULF STREAM. SCATTERED MODERATE CONVECTION IS WITHIN 80 NM
OF THE CENTER. THE WINDOW FOR FURTHER STRENGTHENING IS CLOSING
IN AS THE SYSTEM IS FORECAST TO MOVE OVER COOLER WATERS AND INTO
AN INCREASED SHEAR ENVIRONMENT IN THE NEXT 24 HOURS OR SO.
THEREAFTER BERYL IS EXPECTED TO BEGIN ITS EXTRA-TROPICAL
TRANSITION AS IT INTERACTS WITH A MID-LATITUDE TROUGH.

...TROPICAL WAVES...

A TROPICAL WAVE IS ADDED TO THE 18Z SURFACE ANALYSIS ALONG 38W
SOUTH OF 19N MOVING WEST 15-20 KT. THIS WAVE HAS FAIR SIGNATURE
WITH LOW LEVEL CYCLONIC TURNING EVIDENT ON LAST FEW EVENING VIS
IMAGES AND SHORTWAVE IR PICTURES. DESPITE THE FAIR
SIGNATURE...LITTLE CONVECTION IS ASSOCIATED WITH IT.

A TROPICAL WAVE IS ALONG 50W SOUTH OF 20N MOVING WEST NEAR 15-20
KT. THIS WAVE HAS BEEN CHALLENGING TO TRACK OVER THE PAST FEW
DAYS. HOWEVER...THERE IS MORE CONFIDENCE WITH TODAY'S ANALYZED
POSITION AS A LOW LEVEL SWIRL IS EVIDENT ALONG THE WAVE AXIS.
SIMILAR TO THE WAVE TO IT'S EAST...THIS WAVE ALSO HAS VERY
LITTLE CONVECTION ASSOCIATED WITH IT AS IT IS EMBEDDED IN A
DRY/STABLE ENVIRONMENT.

TROPICAL WAVE IS ADJUSTED SLIGHTLY ALONG 76W S OF 20N MOVING W
NEAR 15 KT. A SMALL UPPER LEVEL LOW OVER JAMAICA AND A LARGER
MORE WELL DEFINED UPPER LOW LOCATED 350 NM NORTH OF THE
DOMINICAN REPUBLIC IS INTERACTING WITH THIS WAVE TRIGGERING A
LARGE AREA OF SCATTERED SHOWERS AND TSTMS ACROSS THE CENTRAL
CARIBBEAN NORTHWARD INTO THE ATLC. AN EARLY AFTERNOON QUIKSCAT
PASS IN THE AREA DISPLAYED THAT STRONGER WINDS...NEAR 25-30
KT... ARE BEHIND THE WAVE AXIS.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N12W 6N25W 10N35W 6N49W 8N63W. THE
ITCZ IS RELATIVELY QUIET WITH ONLY A FEW AREAS OF SCATTERED
MODERATE CONVECTION. SCATTERED MODERATE IS WITHIN 120 NM EITHER
SIDE OF THE AXIS E OF 28W. SIMILAR CONVECTION IS WITHIN 120 NM
SOUTH OF THE AXIS BETWEEN 42W-48W. SCATTERED SHOWERS AND TSTMS
EXTEND ACROSS THE NORTHERN PORTIONS OF SOUTH AMERICA TO THE
LESSER ANTILLES LIKELY ENHANCED BY THE CENTRAL CARIBBEAN
TROPICAL WAVE AND AN UPPER LEVEL LOW.

...DISCUSSION...
GULF OF MEXICO...
A TROUGH OR WEAKNESS EXTENDS FROM TROPICAL STORM BERYL ACROSS
FLORIDA AND INTO THE GULF OF MEXICO. THIS TROUGH IS GENERATING
AN AREA OF SCATTERED SHOWERS AND TSTMS FROM 24N-27N ACROSS THE
GULF. SCATTERED MODERATE CONVECTION HAS MOVED INTO THE YUCATAN
PENINSULA FROM 18N-21N BETWEEN 86W-91W. OUTSIDE OF THESE
AREAS...ISOLATED SHOWERS ARE FOUND. IN THE LARGER PICTURE...A
WELL-DEFINED CENTRAL ATLC SFC RIDGE STRETCHES ACROSS THE GULF TO
A 1018 MB HIGH OVER SOUTHERN LOUISIANA. A RATHER WEAK PRES
GRADIENT LIES ACROSS THE REGION KEEPING WINDS FAIRLY LIGHT.
COMPUTER MODELS SUGGEST THAT A FAIR AMOUNT OF MOISTURE WILL
REMAIN IN THE GULF OVER THE NEXT FEW DAYS ASSOCIATED WITH THE
TAIL TROUGH OF BERYL AND AN APPROACHING TROPICAL WAVE CURRENTLY
IN THE CENTRAL CARIBBEAN.

CARIBBEAN SEA...
AN UPPER LEVEL TROUGH EXTENDS ACROSS THE N CARIBBEAN FROM 21N91W
TO AN UPPER LOW OVER JAMAICA AT 18N78W TO 17N71W. A WEAK BROAD
UPPER LEVEL RIDGE IS OVER THE S CARIBBEAN EXTENDING FROM COSTA
RICA TO THE N COAST OF VENEZUELA. A TROPICAL WAVE ALONG 76W
INTERACTING WITH THE UPPER LOW NEAR JAMAICA AND ANOTHER UPPER
LOW IN THE WEST ATLC IS PRODUCING A WIDE AREA OF SCATTERED
SHOWERS AND TSTMS ACROSS THE CARIBBEAN. SOME OF THE MOST
ORGANIZED ACTIVITY IS WITHIN 120 NM OF THE WAVE AXIS AND OVER
HISPANIOLA AND PUERTO RICO ENHANCED BY THE UPSLOPE FLOW OF LOCAL
HIGH TERRAIN. SCATTERED MODERATE CONVECTION IS ALSO FOUND
FURTHER SOUTH ACROSS NICARAGUA AND HONDURAS LIKELY CONTRIBUTED
TO THE ITCZ. OUTSIDE OF THE OUTLINED AREAS...THERE ARE
ISOLATED/SCATTERED SHOWERS AND TSTMS. TRADE WINDS NEAR 20 KT
EXIST ACROSS MOST OF THE CARIBBEAN. THESE WINDS ARE EXPECTED TO
SLOWLY INCREASE OVER THE NEXT FEW DAYS AND MAY REACH GALE FORCE
LATE THIS WEEKEND OR EARLY NEXT WEEK.

ATLANTIC OCEAN...
T.S. BERYL IS EMBEDDED IN DEEP SLY FLOW E OF AN UPPER TROUGH OVER
THE EASTERN UNITED STATES. ABUNDANT UPPER LEVEL MOISTURE
STRETCHES FROM THE CARIBBEAN ACROSS THE BAHAMAS AND FLORIDA TO
THE TROPICAL STORM. SCATTERED SHOWERS AND TSTMS HAVE DEVELOPED
IN THIS MOIST ENVIRONMENT FROM 23N-30N W OF 75W. A LULL IN THE
ACTIVITY LIES FROM 69W-75W. A MORE IMPRESSIVE AREA OF SCATTERED
SHOWERS AND TSTMS EXISTS FURTHER EAST FROM 18N-30N BETWEEN
59W-69W ASSOCIATED WITH A SFC TROUGH ALONG 21N69W 31N63W AND
DIFFLUENT FLOW ON THE E SIDE OF THE UPPER LOW. THE REMAINDER OF
THE ATLC IS DOMINATED BY A 1029 MB HIGH NEAR 36N51W AND TYPICAL
TRADE WIND FLOW. MOSTLY FAIR TRANQUIL WEATHER IS UNDER THE
INFLUENCE OF THE RIDGE E OF 59W. A LARGE AREA OF SAHARAN DUST IS
LOCATED BEHIND THE EASTERN-MOST ANALYZED TROPICAL WAVE LOCATED E
OF 36W TO AFRICA BETWEEN 7N-25N LIMITING ANY SHOWER ACTIVITY IN
THE AREA.

$$
CANGIALOSI


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