[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 030006
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE JUL 02 2013

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...TROPICAL WAVES...
A NEW TROPICAL WAVE HAS COME OFF THE WEST AFRICAN COAST. ITS
AXIS IS EMBEDDED WITHIN THE MONSOON TROUGH AND IS CURRENTLY
ALONG 16N18W TO 06N17W. TOTAL PRECIPITABLE WATER IMAGERY SHOW
HIGH MOISTURE WITHIN ITS ENVIRONMENT AT THE LOWER LEVELS AND
WATER VAPOR IMAGERY MODERATE MOISTURE AT THE MIDDLE LEVELS.
HOWEVER...NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE
WAVE AT THIS TIME.

TROPICAL WAVE IS ALONG 19N31W TO 12N32W MOVING WEST NEAR 5 KT.
SAL DRY AIR SPREADS OVER THE WAVE ENVIRONMENT AS INDICATED IN
THE METEOSAT-9 SAL TRACKING PRODUCT WHICH IS HINDERING ANY
CONVECTIVE ACTIVITY.

TROPICAL WAVE MOVING TOWARDS THE EASTERN CARIBBEAN...WITH AXIS
ALONG 19N55W TO 11N55W. IT IS MOVING NEAR 15 KT WITHIN A LOWER
LEVELS DRY ENVIRONMENT. THE METEOSAT-9 SAL TRACKING PRODUCT SHOW
THIS WAVE IS EMBEDDED WITHIN SAL DRY AIR WHICH IS INHIBITING
CONVECTION AT THIS TIME.

TROPICAL WAVE AXIS OVER THE WESTERN CARIBBEAN ALONG 23N82W TO
17N82W MOVING NEAR 20 KT. EVEN THAT THIS WAVE IS ENHANCING
NUMEROUS MODERATE/ISOLATED STRONG CONVECTION N OF 18N WEST OF
78W...ITS STRUCTURE HAS WEAKENED WITH ITS SOUTHERN PART BEING
TRANSITIONED TO A SURFACE TROUGH ALONG THE COASTS OF
HONDURAS...NICARAGUA AND COASTA RICA.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST NEAR
11N15W TO 09N21W. THE ITCZ BEGINS NEAR 09N21W AND CONTINUES
ALONG 10N30W 07N40W 02N50W. ISOLATED MODERATE CONVECTION IS
WITHIN 250 NM S OF THE ITCZ AXIS AND WITHIN 120 NM N OF THE
AXIS BETWEEN 33W-51W.

...DISCUSSION...

GULF OF MEXICO...
A DEEP AND BROAD UPPER LEVEL TROUGH EXTENDING AN AXIS ACROSS
CENTRAL U.S. INTO THE GULF IS SUPPORTING A WEAK STATIONARY FRONT
THAT ENTERS THE BASIN BY SOUTHERN ALABAMA NEAR 30N88W TO 27N89W
WHERE IT TRANSITIONS TO A SURFACE TROUGH TO 24N93W. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 40 NM EITHER SIDE OF
THE FRONTAL BOUNDARY AND EXTENDS TO THE SW GULF FROM 21N-24N
BETWEEN 93W-97W. ADVECTION OF LOWER AND MIDDLE LEVELS MOISTURE
FROM THE WEST CARIBBEAN TO THE EASTERN GULF COMBINED WITH UPPER
LEVEL DIFFLUENCE CONTINUE ENHANCING SCATTERED MODERATE
CONVECTION AND THUNDERSTORMS ACROSS FLORIDA AS WELL AS S OF 26N
EAST OF 83W...INCLUDING THE STRAITS OF FLORIDA. SIMILAR
CONVECTION IS S OF 23N BETWEEN THE YUCATAN CHANNEL AND THE
YUCATAN PENINSULA. WINDS ARE FAIRLY LIGHT ACROSS MUCH OF THE
AREA WITH STRONGER SOUTHERLY WINDS ACROSS THE SE GULF REACHING
UP TO 15 KT.

HIGH MOISTURE ADVECTION TO THE GULF WILL CONTINUE WITHIN THE
NEXT 48 HOURS AS WELL AS A DIFFLUENT UPPER LEVEL PATTERN WHICH
WILL CONTINUE TO ENHANCE PRECIPITATION AND THUNDERSTORMS. THESE
WILL EXTENDS TO THE CENTRAL GULF AS THE UPPER LEVEL RIDGE OVER
WESTERN CARIBBEAN AND PORTIONS OF CUBA DRIFTS WESTWARD. BROAD
SURFACE TROUGHING WILL DOMINATES MUCH OF THE GULF AND A LOW MAY
FORM IN THE NE GULF.

CARIBBEAN SEA...
A TROPICAL WAVE WITH AXIS CURRENTLY OVER WESTERN CUBA AND UPPER
LEVEL DIVERGENCE IS ENHANCING NUMEROUS MODERATE/ISOLATED STRONG
CONVECTION AND THUNDERSTORMS ACROSS CUBA AND FROM 17N-22N
BETWEEN 78W-85W. THE SOUTHERN PORTION OF THIS TROPICAL WAVE
TRANSITIONED TO A SURFACE TROUGH THAT IS ALONG THE COASTLINES OF
HONDURAS AND NICARAGUA. ISOLATED MODERATE
CONVECTION/THUNDERSTORMS ARE WITHIN 130 NM N OF THE HONDURAS
COASTLINE BETWEEN 82W-85W ASSOCIATED WITH THE NORTHERN PART OF
THIS TROUGH. SIMILAR CONVECTION IS OCCURRING IN THE SOUTHERN
CARIBBEAN WITHIN 80 NM N OF THE MONSOON TROUGH AXIS BETWEEN 79W-
81W. UPPER LEVEL DIFFLUENCE FROM THE RIDGE OVER THE WEST
CARIBBEAN AND A CYCLONIC CIRCULATION OVER THE WEST ATLC IS
ENHANCING SHOWERS AND THUNDERSTORMS ACROSS LA HISPANIOLA. SIMILAR
CONVECTION IS OCCURRING ACROSS THE MONA PASSAGE.
OTHERWISE...TRADEWINDS UP TO 20 KT ABOUND ACROSS THE BASIN WITH
THE MAXIMUM WINDS BEING IN THE CENTRAL CARIBBEAN DUE TO A
TIGHTER PRESSURE GRADIENT.

A NEW TROPICAL WAVE WILL MOVE INTO THE EASTERN CARIBBEAN
WEDNESDAY MORNING.

HISPANIOLA...
UPPER LEVEL DIFFLUENCE FROM THE RIDGE OVER THE WEST CARIBBEAN
AND A CYCLONIC CIRCULATION OVER THE WEST ATLC IS ENHANCING
SHOWERS AND THUNDERSTORMS ACROSS LA HISPANIOLA. A COMBINATION OF
A PERSISTENT UPPER LEVEL SYNOPTIC PATTERN AND PATCHES OF LOW
LEVEL MOISTURE MOVING ACROSS THE ISLAND WILL CONTINUE TO ENHANCE
RAINSHOWERS/THUNDERSTORMS WITHIN THE NEXT 48 HOURS.

ATLANTIC OCEAN...
BROAD SURFACE RIDGING COVERS THE WEST AND CENTRAL ATLC AROUND A
1029 MB HIGH NEAR 35N61W. SCATTERED SHOWERS/THUNDERSTORMS ARE
OFF THE COAST OF FLORIDA WEST OF 78W ASSOCIATED WITH AN UPPER
LEVEL TROUGH OVER THE GULF OF MEXICO. A WEAK SURFACE IS ALONG
30N64W TO 27N62W WITH NO CONVECTION ASSOCIATED WITH IT. THE
REMAINDER OF THE EASTERN ATLC IS DOMINATED BY BROAD SURFACE
RIDGING EXTENDING FROM A PAIR OF 1029 MB AZORES HIGHS.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
NR

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