[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 282344
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI JUN 28 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
2245 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 13N25W TO 5N26W MOVING WEST AT 5-10 KT.
THE WAVE IS ILL-DEFINED AT THE SURFACE...BUT ALIGNS WELL WITH A
700 MB TROUGH AXIS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED
WITH THE WAVE.

TROPICAL WAVE IS ALONG 18N54W TO 5N59W MOVING WNW AT 15-20 KT.
THE WAVE COINCIDES WITH A LARGE SURGE OF DEEP LAYER MOISTURE
PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. SURFACE
OBSERVATIONS INDICATE CLEAR CYCLONIC FLOW IS AROUND THE WAVE
AXIS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-
19N BETWEEN 51W-60W. SIMILAR ACTIVITY IS FROM 8N-12N BETWEEN 60W-
63W.

TROPICAL WAVE IS MOVING THROUGH THE WESTERN CARIBBEAN ALONG
23N80W TO 9N79W MOVING WEST AT 15-20 KT. A MODERATE SURGE OF
DEEP LAYER MOISTURE IS EAST OF THE AXIS. THE WAVE IS HELPING
ENHANCE SCATTERED MODERATE/STRONG CONVECTION OVER CUBA AND NORTH
OF JAMAICA. SCATTERED MODERATE CONVECTION IS ALSO IN THE SW
CARIBBEAN SOUTH OF 12N BETWEEN 77W-83W. THIS ACTIVITY IS ALSO
ASSOCIATED WITH THE MONSOON TROUGH THAT EXTENDS FROM COSTA RICA
TO NORTHERN COLOMBIA.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE COAST OF SENEGAL NEAR 14N17W
TO 8N21W 5N30W. THE ITCZ BEGINS NEAR 5N30W AND CONTINUES ALONG
5N44W 3N52W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS
FROM 8N-11N BETWEEN 15W-19W.

...DISCUSSION...

GULF OF MEXICO...
WEAK SURFACE RIDGING IS ACROSS THE GULF OF MEXICO AROUND A 1016
MB HIGH NEAR 26N90W. LIGHT ANTI-CYCLONIC FLOW IS AROUND THE
RIDGE CENTER. ALOFT...A HORIZONTALLY ALIGNED UPPER TROUGH
EXTENDS FROM NEAR 26N81W TO AN UPPER LOW NEAR 24N95W. UPPER
RIDGING IS BUILDING IN FROM THE NORTH. THIS PATTERN PROVIDES
DIFFLUENT FLOW OVER THE YUCATAN PENINSULA WHERE SCATTERED
SHOWERS/THUNDERSTORMS ARE FROM 17N-22N BETWEEN 86W-91W.
SCATTERED SHOWERS ARE ALSO OVER MUCH OF THE FLORIDA PENINSULA. A
SHORTWAVE UPPER TROUGH A LITTLE NORTH OF THE NE GULF COAST IS
SUPPORTING SHOWERS/THUNDERSTORMS OVER THE FLORIDA PANHANDLE
WHERE BROAD SURFACE TROUGHING IS ALSO PRESENT. THE SHORTWAVE
UPPER TROUGH WILL CONTINUE TO PUSH SOUTH AND WILL CONTINUE TO
PRODUCE SHOWERS/THUNDERSTORMS OVER THE NE GULF. WEAK SURFACE
RIDGING WILL REMAIN OVER THE WESTERN GULF.

CARIBBEAN SEA...                                              A
TROPICAL WAVE IS MOVING THROUGH THE WESTERN CARIBBEAN ALONG 80W.
IT IS HELPING ENHANCE SCATTERED SHOWERS/THUNDERSTORMS OVER MUCH
OF CUBA...AND NORTH OF JAMAICA. SCATTERED SHOWERS ARE ALSO IN
THE SW CARIBBEAN SOUTH OF 12N BETWEEN 77W-86W. THIS ACTIVITY IS
ALSO ASSOCIATED WITH THE MONSOON TROUGH AXIS THAT EXTENDS FROM
COSTA RICA TO NORTHERN COLOMBIA. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE ALSO OVER MUCH OF CENTRAL AMERICA. EAST OF THE
WAVE...CONDITIONS ARE MOSTLY FAIR AS SEVERAL STATIONS REPORT THE
PRESENCE OF DUST. A FEW SHOWERS/THUNDERSTORMS HAVE STILL POPPED
UP OVER HISPANIOLA. A TROPICAL WAVE EAST OF THE LESSER ANTILLES
IS ALSO BEGINNING TO BRING A FEW SHOWERS TO THE WINDWARD
ISLANDS. TRADEWIND FLOW OF 15-20 KT IS THROUGHOUT MUCH OF THE
BASIN. ALOFT...BROAD RIDGING COVERS THE MAJORITY OF THE AREA
EXCEPT FOR AN UPPER TROUGH OVER THE FAR EASTERN CARIBBEAN ALONG
64W. THE TROPICAL WAVE IN THE WESTERN CARIBBEAN WILL CONTINUE TO
MOVE WEST...WHILE THE NEXT TROPICAL WAVE WILL MOVE INTO THE
EASTERN CARIBBEAN OVER THE NEXT 12 HOURS.

HISPANIOLA...
A FEW ISOLATED SHOWERS/THUNDERSTORMS ARE LOCATED OVER THE
NORTHERN PORTION OF HISPANIOLA FROM 19N-20N BETWEEN 70W-73W.
DUST IS PRESENT IN THE AREA AND KEEPING CONVECTION TO A LOWER
AMOUNT TODAY. THIS WILL LIKELY REMAIN THE CASE FOR THE NEXT DAY
OR SO UNTIL MOISTURE WITH THE NEXT TROPICAL WAVE REACHES THE
ISLAND BY MIDDAY SUNDAY.

ATLANTIC OCEAN...
BROAD SURFACE RIDGING COVERS THE WEST ATLC AROUND A 1022 MB HIGH
NEAR 32N60W. A FEW SHOWERS/THUNDERSTORMS ARE NOTED OVER THE
BAHAMAS ASSOCIATED WITH MOISTURE NEAR A TROPICAL WAVE TO THE
SOUTH. ALOFT...A COUPLE UPPER LOWS ARE OVER THE AREA WITH THE
FIRST NEAR 28N78W. THIS UPPER LOW IS LIKELY CONTRIBUTING TO THE
ACTIVITY OVER THE BAHAMAS. A SECOND UPPER LOW IS NEAR 23N64W. IT
SUPPORTS A WEAK SURFACE TROUGH ALONG 25N66W TO 20N61W. SCATTERED
SHOWERS ARE UP TO 160 NM NE OF THE AXIS. THE REMAINDER OF THE
BASIN IS DOMINATED BY BROAD SURFACE RIDGING EXTENDING FROM A
1036 MB HIGH NEAR 46N21W. ALOFT...UPPER RIDGING COVERS MOST OF
THE AREA WITH AN AXIS EXTENDING FROM THE TROPICAL ATLC NEAR
12N48W TO NEAR 30N22W. AN UPPER LOW IS TO THE NORTHWEST NEAR
33N43W. THE UPPER LOW IS NOT CAUSING ANY ACTIVE WEATHER IN THE
AREA. THE LAST VISIBLE SATELLITE IMAGES OF THE DAY INDICATE THAT
A LARGE AREA OF SAHARAN DUST EXTENDS FROM THE COAST OF AFRICA TO
NEAR 47W AROUND THE TROPICAL WAVE IN THE EASTERN ATLC.

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

$$
WALTON


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