[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 021120
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU JUL 02 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 1000 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 24W S OF 14N MOVING W 15-20 KT.
THIS WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED
ON TOTAL PRECIPITABLE WATER IMAGERY. SATELLITE IMAGERY INDICATES
LOW-LEVEL CYCLONIC FLOW AROUND THE VICINITY OF THE WAVE AXIS.
ISOLATED MODERATE CONVECTION IS FROM 7N-11N BETWEEN 21W-27W.

A TROPICAL WAVE IS ALONG 39W S OF 12N MOVING W 15-20 KT. THIS
WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM OBSERVED ON
TOTAL PRECIPITABLE WATER IMAGERY. NO DEEP CONVECTION IS
CURRENTLY ASSOCIATED WITH THIS WAVE.

A TROPICAL WAVE EXTENDS FROM 17N66W TO 3N69W MOVING W 15-20 KT.
POSITION IS BASED ON CONTINUITY. THIS WAVE IS JUST E OF AN UPPER
LEVEL RIDGE OVER THE ERN CARIBBEAN WHICH IS INHIBITING
CONVECTION BESIDES A CLUSTER OF SCATTERED MODERATE/ISOLATED
STRONG CONVECTION OVER VENEZUELA FROM 7N-10N BETWEEN 67W-70W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 13N17W 9N22W 6N31W 5N47W AND
INTO NE S AMERICA NEAR 5N57W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 4N-8N BETWEEN 28W-35W. SCATTERED MODERATE
CONVECTION IS FROM 4N-6N BETWEEN 45W-53W.

...DISCUSSION...

GULF OF MEXICO...
ISOLATED SHOWERS/THUNDERSTORMS REMAIN ACROSS THE ERN GULF OF
MEXICO FROM 24N-28N E OF 86W. UPPER LEVEL DIFFLUENCE BETWEEN AN
UPPER LEVEL TROUGH EXTENDING DOWN THE ERN UNITED STATES INTO THE
CENTRAL GULF TO NEAR 24N91W AND AN UPPER LEVEL RIDGE OVER THE
WRN ATLC ALONG WITH MOIST SWLY FLOW ALOFT ARE SUPPORTING THE
SHOWER ACTIVITY. A SURFACE TROUGH IS OVER THE BAY OF CAMPECHE
FROM 16N92W TO 20N91W. SURFACE CONVERGENCE NEAR THE TROUGH ALONG
WITH UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL RIDGE OVER
MEXICO AND AN UPPER LEVEL TROUGH OVER THE WRN CARIBBEAN ARE
SUPPORTING A LARGE CLUSTER OF NUMEROUS SHOWERS/THUNDERSTORMS
OVER THE YUCATAN PENINSULA AND THE BAY OF CAMPECHE FROM 16N-21N
BETWEEN 91W-94W. THE REMAINDER OF THE NW GULF OF MEXICO IS
UNDER A WEAK RIDGE AND REMAINS CALM WITH GENERALLY
FAIR WEATHER AND LIGHT WINDS. THIS IS SUPPORTED BY UPPER LEVEL
CONFLUENCE WHICH IS PROVIDING SUBSIDENCE OVER THE NW GULF.

CARIBBEAN SEA...
AN UPPER LEVEL LOW IS OVER THE WRN CARIBBEAN NEAR 17N82W. UPPER
LEVEL CONFLUENCE NW OF THE UPPER LEVEL LOW IS PROVIDING
SUBSIDENCE OVER THE NW CARIBBEAN ALONG WITH DEEP LAYER DRY AIR
BRINGING THE NW GULF GENERALLY FAIR WEATHER. ATMOSPHERIC
INSTABILITY NEAR THE UPPER LOW IS SUPPORTING ISOLATED
SHOWERS/POSSIBLE THUNDERSTORMS S OF 15N W OF 80W AND FROM
18N-20N BETWEEN 802-92W. AN UPPER LEVEL RIDGE IS OVER THE ERN
CARIBBEAN CENTERED AROUND AN UPPER LEVEL HIGH NEAR 12N72W. UPPER
LEVEL DIFFLUENCE BETWEEN THE UPPER LEVEL TROUGH OVER THE W
CARIBBEAN AND THE UPPER LEVEL RIDGE OVER THE E CARIBBEAN ALONG
WITH MOIST SLY FLOW ALOFT ARE SUPPORTING ISOLATED SHOWERS IN THE
CENTRAL CARIBBEAN FROM 14N-16N BETWEEN 77W-80W. SURFACE
CONVERGENCE NEAR A 1009 MB SURFACE LOW OVER COLUMBIA NEAR 7N76W
IS SUPPORTING NUMEROUS SHOWERS/THUNDERSTORMS S OF 11N BETWEEN
76W-81W. THIS ACTIVITY IS BEING ENHANCED BY A START OF THE ITCZ
IN THE E PACIFIC. THE REMAINDER OF THE ERN CARIBBEAN IS
EXPERIENCING GENERALLY FAIR WEATHER DESPITE THE PRESENCE OF A
TROPICAL WAVE DUE TO SUBSIDENCE ALOFT FROM UPPER LEVEL
CONFLUENCE E OF THE UPPER LEVEL RIDGE. ELY TRADE WINDS OF 20 KT
COVER THE MAJORITY OF THE CARIBBEAN REACHING 30 KT IN SOME AREAS.

ATLANTIC OCEAN...
UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL TROUGH EXTENDING
DOWN THE ERN UNITED STATES INTO THE CENTRAL GULF AND AN UPPER
LEVEL RIDGE OVER THE WRN ATLC CENTERED AROUND AN UPPER LEVEL
HIGH NEAR 28N65W ALONG WITH MOIST SWLY FLOW ALOFT ARE SUPPORTING
ISOLATED SHOWERS/THUNDERSTORMS ACROSS THE NW ATLC EXTENDING FROM
THE ERN GULF N OF 26N W OF 76W. A SURFACE TROUGH IN THE CENTRAL
ATLC EXTENDS FROM 31N48W TO 29N49W. SURFACE CONVERGENCE NEAR
THIS TROUGH AS WELL AS A 1017 MB SURFACE LOW N OF THE DISCUSSION
AREA NEAR 34N48W ARE SUPPORTING SCATTERED SHOWERS N OF 28N
BETWEEN 42W-52W. A BROAD SURFACE RIDGE COVERS THE REMAINDER OF
THE ATLC BRINGING GENERALLY FAIR WEATHER. THE RIDGE IS ANCHORED
BY A SERIES OF SURFACE HIGHS...A 1023 MB HIGH CENTERED NEAR
27N55W...A 1025 MB HIGH CENTERED NEAR 29N33W...AND A 1025 MB
HIGH AT THE EDGE OF THE DISCUSSION AREA NEAR 32N22N.

$$
WALTON






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