[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 051127
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI JUL 05 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 19N28W TO 9N28W MOVING WEST AT 5-10 KT.
THE WAVE IS EMBEDDED WITHIN AN AREA OF INCREASED MOISTURE
PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. A LARGE SAHARAN AIR
LAYER SURROUNDS A GOOD PORTION OF THE WAVE...WHICH IS INHIBITING
ANY DEEP CONVECTION NEAR THE AXIS. HOWEVER...A CLUSTER OF
SCATTERED MODERATE CONVECTION IS WITHIN THE MONSOON TROUGH FROM
6N-9N BETWEEN 24W-28W.

TROPICAL WAVE IS ALONG 19N48W TO 8N53W MOVING WEST NEAR 15 KT.
THE WAVE COINCIDES WITH A LARGE SURGE OF DEEP LAYER MOISTURE
PRESENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE
CONVECTION IS FROM 13N-16N BETWEEN 43W-53W.

TROPICAL WAVE IS ALONG 21N75W TO 11N75W MOVING WEST THROUGH THE
CENTRAL CARIBBEAN NEAR 15 KT. ONLY A WEAK MOISTURE SIGNAL IS
EVIDENT NEAR THE WAVE WITH MUCH HIGHER MOISTURE CONTENT FARTHER
WEST OVER THE WESTERN CARIBBEAN. DRY AIR IS OVER THE AREA ALOFT
EXCEPT NEAR THE NORTHERN PORTION OF THE WAVE WHERE DIFFLUENT
FLOW IS PRESENT AROUND A NARROW UPPER TROUGH NEAR 79W. ISOLATED
MODERATE CONVECTION IS NEAR THE NORTHERN PORTION OF THE WAVE
FROM 17N-21N BETWEEN 75W-77W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE COAST OF MAURITANIA NEAR
18N16W TO 11N20W 7N29W. THE ITCZ BEGINS NEAR 7N29W AND CONTINUES
ALONG 7N38W 7N47W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS FROM 7N-11N BETWEEN 14W-15W.

...DISCUSSION...

GULF OF MEXICO...
MOIST CONDITIONS REMAIN ACROSS MUCH OF THE GULF OF MEXICO. THIS
IS DUE TO A COMBINATION OF MOIST SOUTHERLY FLOW AT THE SURFACE
THROUGHOUT MUCH OF THE AREA...AND MOIST SOUTHWESTERLY AND
DIFFLUENT FLOW ALOFT BETWEEN AN UPPER LEVEL TROUGH OVER THE
CENTRAL CONUS THAT IS PUSHING INTO THE NW GULF...AND AN UPPER
LEVEL RIDGE OVER THE REMAINDER OF THE BASIN EXTENDING FROM THE
BAY OF CAMPECHE NEAR 20N93W TO 31N83W. ISOLATED SHOWERS AND
POSSIBLE THUNDERSTORMS ARE THROUGHOUT THE AREA EXCEPT FOR THE NW
CORNER WHERE SKIES ARE CLEAR. MORE SCATTERED ACTIVITY IS FROM
21N-24N BETWEEN 91W-94W...AND FROM 23N-26N BETWEEN 87W-92W. A
SURFACE TROUGH MAY BE ENHANCING SOME OF THE ACTIVITY WITH AXIS
ALONG 26N93W TO 18N94W. BROAD SURFACE TROUGHING WILL REMAIN OVER
THE WESTERN GULF WITH MOISTURE CONTINUING TO FLOW OVER MUCH OF
THE BASIN FOR THE NEXT DAY OR SO.

CARIBBEAN SEA...
MODERATE MOISTURE IS THROUGHOUT THE WESTERN CARIBBEAN INDICATED
BY TOTAL PRECIPITABLE WATER IMAGERY. SOME OF THIS IS MOISTURE
ALOFT THAT IS STREAMING OVER THE AREA IN NORTHERLY FLOW AROUND
AN UPPER LEVEL RIDGE OVER THE EASTERN GULF OF MEXICO. A NARROW
UPPER TROUGH IS TO THE EAST ALONG 78W/79W...WHICH IS PROVIDING
DIFFLUENT FLOW ALOFT OVER THE NE CARIBBEAN. SCATTERED SHOWERS
ARE CURRENTLY OVER CENTRAL CUBA AS WELL AS TO THE SOUTH FROM 17N-
23N BETWEEN 78W-81W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
ARE ALSO FROM 13N-17N BETWEEN 82W-85W. A FEW SHOWERS AND
THUNDERSTORMS ARE NEAR THE NORTHERN PORTION OF THE WAVE OVER
EASTERN CUBA. WIDELY ISOLATED SHOWERS ARE ALSO OVER PANAMA
ASSOCIATED WITH THE MONSOON TROUGH THAT EXTENDS FROM COSTA RICA
TO A 1010 MB SURFACE LOW OVER NORTHERN COLOMBIA. DRY AIR ALOFT
AROUND AN INVERTED UPPER TROUGH ALONG 73W IS LIMITING CONVECTION
NEAR THE REMAINDER OF THE WAVE. DRY AIR ALOFT ALSO COVERS THE
EASTERN CARIBBEAN WHERE VERY CLEAR SKIES ARE NOTED EXCEPT FOR A
FEW ISOLATED SHOWERS FROM 12N-15N EAST OF 64W. SEVERAL STATIONS
IN THE LESSER ANTILLES ARE REPORTING DUST. TRADEWIND FLOW OF 15-
20 KT IS THROUGHOUT MUCH OF THE AREA WITH A SMALL AREA OF 25 KT
WINDS NEAR THE COAST OF COLOMBIA IN THE CENTRAL CARIBBEAN. THE
TROPICAL WAVE IS EXPECTED TO CONTINUE MOVING WEST WHERE MOIST
CONDITIONS WILL REMAIN OVER THE WESTERN CARIBBEAN FOR AT LEAST
THE NEXT 24 HOURS.

HISPANIOLA...
SHOWERS IMPACTING HISPANIOLA EARLIER HAVE NOW DISSIPATED LEAVING
THE ISLAND FAIRLY CLEAR. DRIER AIR HAS MOVED OVER THE AREA WHICH
WILL KEEP CONVECTION TO A MINIMUM EXCEPT DURING PEAK DAYTIME
HEATING WHERE AFTERNOON ACTIVITY WILL STILL LIKELY OCCUR. A
DRIER AIRMASS WILL CONTINUE TO IMPACT THE ISLAND UNTIL THE NEXT
TROPICAL WAVE APPROACHES EARLY NEXT WEEK.

ATLANTIC OCEAN...
BROAD SURFACE RIDGING DOMINATES THE WEST ATLC AROUND A 1028 MB
HIGH NEAR 33N69W. THE RIDGE IS SUPPORTED BY BROAD UPPER RIDGING
CENTERED NEAR 37N68W. HOWEVER...A NARROW UPPER TROUGH ALONG
78W/79W IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS OFF THE
COAST OF FLORIDA WEST OF 75W. MORE SCATTERED ACTIVITY IS FROM
23N-26N BETWEEN 78W-80W. AN UPPER LEVEL LOW IS CENTERED NEAR
23N59W SUPPORTING A FEW ISOLATED SHOWERS/THUNDERSTORMS FROM 22N-
27N BETWEEN 60W-63W. A DISSIPATING COLD FRONT ALSO EXTENDS INTO
THE AREA ALONG 30N50W TO 28N58W. NO SHOWERS ARE ASSOCIATED WITH
THE BOUNDARY. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE
RIDGING. BROAD UPPER RIDGING COVERS THE TROPICAL ATLC CENTERED
NEAR 16N27W. AN UPPER LOW IS TO THE NORTH NEAR 34N19W...BUT IS
NOT CAUSING ANY ACTIVE WEATHER IN THE AREA. VERY DRY AIR IS
THROUGHOUT THIS AREA DUE TO THE PRESENCE OF A BROAD SAHARAN AIR
LAYER.

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

$$
WALTON


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