[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 031050
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED JUN 03 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 36W/37W S OF 14N MOVING W ABOUT 10 KT.
THE 03/06 UTC MAP SHOWED AN INCREASED IN LATITUDINAL EXTENT
BASED ON THE ENVELOPE OF CYCLONIC TURNING IN THE STRATOCUMULUS
CLOUDS AND THE AMPLIFICATION NOTED IN THE MICROWAVE DERIVED
PRECIPITABLE WATER PRODUCT. GFS INITIALIZES THIS WAVE REASONABLY
WELL SHOWING DISTINCT TROUGHING AT 925 MB. SCATTERED MODERATE
CONVECTION IS MAINLY CONFINED TO WITHIN THE INTERSECTION OF THE
ITCZ FROM 3N-6N BETWEEN 34W-38W.

A TROPICAL WAVE IS OVER THE SW CARIBBEAN ALONG 75W S OF 15N
MOVING W NEAR 15 KT. THIS WAVE HAS LITTLE SIGNATURE ON SATELLITE
IMAGERY OR IN AVAILABLE SFC OBSERVATIONS. ITS CURRENT POSITION
IS BASED ON A NARROW WWD MOVING MOISTURE MAXIMUM IN THE TOTAL
PRECIPITABLE WATER FIELD.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 8N13W 5N21W 3N30W 2N42W TO THE
EQUATOR ALONG 51W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS FROM 1N-10N BETWEEN 10W-18W. SIMILAR CONVECTION IS FROM 1N-6N
BETWEEN 18W-30W. SCATTERED MODERATE CONVECTION IS FROM 3N-7N
BETWEEN 32W-38W.

...DISCUSSION...

GULF OF MEXICO...
SCATTERED SHOWERS AND TSTMS PERSIST ACROSS THE CENTRAL GULF N OF
23N BETWEEN 85W-91W. THIS UNSETTLED WEATHER IS ASSOCIATED WITH
UPPER DIFFLUENCE E OF A SHORTWAVE TROUGH AND ENHANCED BY
LOW-LEVEL CONVERGENCE ALONG A WEAKENING SFC TROUGH. THE
REMAINDER OF THE GULF IS IN A MOIST ENVIRONMENT SUPPORTED BY
STRONG SW TO W FLOW ALOFT...WITH ISOLATED SHOWERS AND TSTMS
OCCURRING ELSEWHERE ACROSS THE SE GULF. SE AND S WINDS OF 10 KT
OR LESS ARE AFFECTING MUCH OF THE GULF BASED ON THE LATEST
QUIKSCAT PASS...THOUGH BUOYS REPORTS INDICATE THAT GUSTS OVER 20
KT ARE OCCURRING NEAR THE SHOWERS AND THUNDERSTORMS. THE SFC
TROUGH IS EXPECTED TO MOVE N AND WEAKEN AS A COLD FRONT ENTERS
THE NW GULF THU.

CARIBBEAN SEA...
THE MID-UPPER PATTERN REMAINS AMPLIFIED OVER THE CARIBBEAN WITH
A RIDGE ACROSS THE AREA W OF 70W AND TROUGHING E OF THERE.
STRONG SW/W FLOW ALOFT IS ADVECTING MID-HIGH LEVEL CLOUDINESS N
OF 18N...WITH IR IMAGERY AND LIGHTNING DATA REVEALING A FEW
EMBEDDED TSTMS OVER NRN CENTRAL AMERICA...WHERE THE UPPER FLOW
IS DIFFLUENT. THE ATMOSPHERE IS MORE STABLE OVER MUCH OF THE
REMAINDER OF THE AREA IN AN OVERALL CONFLUENT ZONE BETWEEN THE
TROUGH AND RIDGE. SW FLOW ALOFT E OF THE TROUGH AXIS IS
ADVECTING SOME CLOUDINESS ACROSS THE WINDWARD ISLANDS...BUT THE
DEEP MOISTURE IS S AND E OF THE AREA. IN THE LOWER LEVELS...A
REMNANT SHEAR AXIS AND MOIST ELY FLOW IS GENERATING AND STEERING
SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE NE CARIBBEAN.
TRADE WINDS REMAIN 20-30 KT ACROSS THE S CENTRAL PORTION DUE TO
THE PRESSURE GRADIENT BETWEEN A HIGH OVER THE SUBTROPICAL
CENTRAL ATLC AND LOWER PRES OVER NRN SOUTH AMERICA. E WINDS NEAR
20 KT EXIST OVER THE TOPOGRAPHICALLY ENHANCED GULF OF HONDURAS.
LITTLE CHANGE IN THESE FLOWS ARE FORECAST OVER THE NEXT COUPLE
OF DAYS.

ATLANTIC OCEAN...
WEATHER CONDITIONS ACROSS MUCH OF THE ATLC DISCUSSION ZONE ARE
QUIET...WITH ONLY A FEW AREAS OF UNSETTLED WEATHER TO MENTION.
ISOLATED SHOWERS AND TSTMS ARE S OF 27N W OF 62W...INCLUDING THE
BAHAMAS...ASSOCIATED WITH AN UPPER JET AND THE REMNANTS OF A
LOW-LEVEL SHEAR AXIS. AMPLIFIED DEEP LAYER RIDGING DOMINATES THE
CENTRAL ATLC...THOUGH A STRETCHED UPPER LOW NEAR 25N40W IS
INTERRUPTING THE RIDGE SLIGHTLY. NONETHELESS...FAIR WEATHER
DOMINATES THE MAJORITY OF THE REGION WITH THE EXCEPTION OF
SHALLOW ISOLATED SHOWERS. THE E ATLC IS MAINLY UNDER AN UPPER
TROUGH WITH A DEEP LOW CENTERED SEVERAL HUNDRED NM N OF THE
AZORES. THE SECONDARY SMALLER LOW HAS OPENED INTO AN ELONGATED
TROUGH FROM 31N35W TO 28N43W. WINDS APPEAR MAINLY LESS THAN 20
KT ALONG THE TROUGH BASED ON EARLIER ASCAT DATA. DEEP CONVECTION
IS CONFINED TO THE ITCZ...PARTICULARLY E OF THE TROPICAL WAVE
ALONG 36W AND NEAR ANOTHER WAVE ALONG THE COAST OF AFRICA.

$$
CANGIALOSI



This weather bulletin was brought to you by:
www.nashvilleweather.net