[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 281053
TWDAT

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

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 14N21W TO 05N23W MOVING WEST NEAR 5
KT. THE WAVE AXIS IS MOSTLY EMBEDDED IN A MODERATE MOIST
ENVIRONMENT WITHIN THE ITCZ. CONVECTIVE ACTIVITY HAS SLIGHTLY
INCREASED TO ISOLATED MODERATE CONVECTION COINCIDING WITH
PATCHES OF HIGH LOW LEVEL MOISTURE WITHIN 200 NM EAST OF THE
WAVE AXIS FROM 08N-11N. THE METEOSAT-9 SAL TRACKING PRODUCT
INDICATES THE WAVE IS BEING ENGULFED BY SAL DRY AIR WHICH MAY BE
LIMITING CONVECTIVE ACTIVITY.

TROPICAL WAVE IS ALONG 15N50W TO 06N56W MOVING WEST NEAR 15 KT.
THE WAVE IS EMBEDDED MAINLY IN A HIGH MOIST ENVIRONMENT AND
CONVECTION HAS INCREASED IN THE LAST FEW HOURS. SCATTERED
MODERATE CONVECTION IS WITHIN 230 NM WEST OF THE WAVE AXIS S OF
11N. SCATTERED SHOWERS ARE FROM 12N-14N BETWEEN 48W-51W.

TROPICAL WAVE IS MOVING ACROSS EASTERN CUBA WITH AXIS ALONG
22N74W TO 13N77W MOVING WEST NEAR 10 KT. THE WAVE IS EMBEDDED IN
A MODERATE MOIST ENVIRONMENT AND ONLY ISOLATED SHOWERS ARE
OCCURRING WITHIN 170 NM WEST OF THE AXIS FROM 18N-20N.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN WEST COAST NEAR
10N14W TO 08N22W 06N35W. THE ITCZ BEGINS NEAR 06N35W AND
CONTINUES ALONG 03N42W 01N50W. ISOLATED SHOWERS ARE FROM 01S-08N
BETWEEN 41W-51W.

...DISCUSSION...

GULF OF MEXICO...
WEAK SURFACE RIDGING IS ACROSS THE GULF OF MEXICO AROUND A 1015
MB HIGH NEAR 26N89W. LIGHT ANTI-CYCLONIC FLOW OF 5-10 KT IS
AROUND THE RIDGE. ALOFT...UPPER TROUGHING DOMINATES ACROSS THE
BASIN WITH AN AXIS EXTENDING SW FROM CENTRAL FLORIDA TO CENTRAL
MEXICO. THE TROUGH HAS EMBEDDED AN UPPER LOW IN THE BAY OF
CAMPECHE NEAR 23N93W. THE UPPER LOW IS PROVIDING DIFFLUENT FLOW
ALOFT OVER THE SE GULF WHICH MAY BE ENHANCING ISOLATED SHOWERS/
THUNDERSTORMS. WEAK SURFACE RIDGING WILL REMAIN OVER THE AREA
WITHIN THE NEXT 48 HOURS...A COLD FRONT IS EXPECTED TO EXTEND
ACROSS THE NORTHERN GULF SATURDAY AFTERNOON.

CARIBBEAN SEA...
A TROPICAL WAVE IS MOVING ACROSS EASTERN CUBA WITH AXIS ALONG
22N74W TO 13N77W. THE WAVE IS EMBEDDED IN A MODERATE MOIST
ENVIRONMENT AND ONLY ISOLATED SHOWERS ARE OCCURRING WITHIN 170
NM WEST OF THE AXIS FROM 18N-20N. LARGE CLUSTERS WITH STRONG
CONVECTION AND NUMEROUS THUNDERSTORMS ARE OVER NORTHERN COLOMBIA
AND PANAMA. THIS CONVECTIVE ACTIVITY HAS EXTENDED TO THE
SOUTHERN CARIBBEAN WATERS S OF 12N. THE CONVECTIVE ACTIVITY OVER
THE ABOVE MENTIONED REGION IS MOSTLY ASSOCIATED WITH THE MONSOON
TROUGH AXIS WHICH MOVES ACROSS FROM COSTA RICA TO COLOMBIA.
ALOFT...BROAD UPPER RIDGING COVERS THE MAJORITY OF THE BASIN
CENTERED NEAR 12N75W WHILE BROAD UPPER TROUGHING COVERS THE FAR
EASTERN CARIBBEAN. TRADEWINDS OF 10-15 KT ARE ACROSS MOST OF THE
BASIN EXCEPT THE CENTRAL CARIBBEAN WHERE WINDS ARE 20-25 KT DUE
TO A TIGHTER PRESSURE GRADIENT. THE WAVE WILL CONTINUE TO MOVE
WEST AND ITS AXIS IS EXPECTED TO BE OFF WESTERN CUBA FRIDAY
AFTERNOON. WINDS IN THE CENTRAL CARIBBEAN ARE EXPECTED TO
SUBSIDE TO LESS THAN 25 KT BY SATURDAY AFTERNOON WHILE A NEW
WAVE MOVES ACROSS THE LESSER ANTILLES CARRYING LOTS OF MOISTURE.

HISPANIOLA...
PRIOR CONVECTIVE ACTIVITY ASSOCIATED WITH A TROPICAL WAVE HAS
DISSIPATED. FAIR WEATHER CAN BE EXPECTED THROUGHOUT AT LEAST
SUNDAY MORNING. CONDITIONS WILL DETERIORATE AGAIN MONDAY MORNING
AS A NEW TROPICAL WAVE WILL BE CROSSING THE EASTERN CARIBBEAN
BRINGING LOTS OF MOISTURE AND INCREASING ATMOSPHERE INSTABILITY.

ATLANTIC OCEAN...
BROAD SURFACE RIDGING COVERS THE WEST ATLC AROUND A 1022 MB HIGH
NEAR 31N59W. ALOFT...AN UPPER RIDGE IS ALONG 76W...WHILE AN
UPPER LOW SPINS TO THE EAST NEAR 23N64W. THE UPPER LOW IS
SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS FROM 19N-24N BETWEEN
58W-64W. AT THE SURFACE...BROAD RIDGING DOMINATES EXTENDING FROM
A 1037 MB HIGH NEAR 46N22W. UPPER RIDGING ALSO COVERS THE
EXTREME TROPICAL ATLC. THE METEOSAT-9 SAL TRACKING PRODUCT
DEPICTS A LARGE AREA OF SAHARAN DRY AIR EXTENDS FROM THE COAST
OF AFRICA TO NEAR 50W N OF THE TROPICAL WAVE THAT WILL ENTER THE
EASTERN CARIBBEAN BY SATURDAY AFTERNOON.

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

$$
NR


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