[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 132350
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU JUN 13 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...

A TROPICAL WAVE IMPACTING THE EASTERN CARIBBEAN EXTENDS FROM
19N62W TO 9N63W MOVING W AT 20 KT. THE WAVE LIES WITHIN A SURGE
OF DEEP LAYER MOISTURE PRESENT IN TOTAL PRECIPITABLE WATER
IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 11N-16N BETWEEN
60W-63W. SCATTERED MODERATE/STRONG CONVECTION IS INLAND OVER
VENEZUELA FROM 6N-10N BETWEEN 61W-68W.

A TROPICAL WAVE EXTENDS ACROSS CENTRAL AMERICA INTO THE EAST
PACIFIC ALONG 16N84W TO 8N86W MOVING WEST TO NORTHWEST NEAR 10
KT. SCATTERED MODERATE/STRONG CONVECTION IS FROM 10N-16N BETWEEN
83W-88W. SCATTERED MODERATE CONVECTION IS FROM 11N-14N BETWEEN
79W-83W.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA-BISSAU NEAR
11N16W TO 6N23W. THE ITCZ BEGINS NEAR 6N23W AND CONTINUES ALONG
4N40W 5N50W 8N59W. SCATTERED MODERATE/STRONG CONVECTION IS FROM
3N-8N BETWEEN 19W-26W...AND FROM 6N-8N BETWEEN 31W-35W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-11N
BETWEEN 51W-60W.

...DISCUSSION...

THE GULF OF MEXICO...
WEAK SURFACE RIDGING DOMINATES THE GULF OF MEXICO AROUND A 1019
MB HIGH NEAR 26N89W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL
RIDGE COVERING THE WESTERN GULF CENTERED OVER CENTRAL MEXICO
NEAR 19N101W. LIGHT ANTI-CYCLONIC WINDS ARE AROUND THE HIGH
CENTER INCREASING TO 10-15 KT OVER THE WESTERN GULF. AN UPPER
LEVEL LOW IS SITTING OVER THE FLORIDA KEYS NEAR 25N82W. WHILE
DRY AIR ALOFT AROUND THE WEST SIDE OF THE UPPER LOW IS KEEPING
THE CENTRAL GULF CLEAR...DIFFLUENCE AROUND THE EAST SIDE IS
PRODUCING SCATTERED SHOWERS/THUNDERSTORMS OVER THE SOUTHERN HALF
OF THE FLORIDA PENINSULA CONTINUING INTO THE SE GULF NORTH OF
CUBA AND INTO THE BAHAMAS. A FEW ISOLATED SHOWERS ARE ALSO OVER
THE NW GULF AS MOIST AIR WRAPS AROUND THE NORTHERN PART OF THE
UPPER RIDGE OVER MEXICO. SURFACE RIDGING WILL REMAIN THE
DOMINANT FEATURE UNTIL A FRONTAL BOUNDARY MOVES IN TO THE NE
GULF TOMORROW AFTERNOON.

THE CARIBBEAN SEA...
A TROPICAL WAVE OVER CENTRAL AMERICA IS SUPPORTING WIDESPREAD
SHOWERS/THUNDERSTORMS OVER HONDURAS...NICARAGUA...COSTA
RICA...AND PANAMA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE
ALSO OVER WATER IN THE SW CARIBBEAN FROM 11N-14N BETWEEN 79W-
83W. A FEW ISOLATED SHOWERS ARE ALSO OVER THE NW CARIBBEAN. THE
WAVE IS BEING ENHANCED BY AN UPPER TROUGH/LOW ALONG 83W. DAYTIME
HEATING AND INSTABILITY ARE PRODUCING SCATTERED
SHOWERS/THUNDERSTORMS ACROSS CUBA...JAMAICA...AND HISPANIOLA.
THE UPPER LOW NEAR THE FLORIDA KEYS IS HELPING SUPPORT THIS
ACTIVITY. THE CENTRAL CARIBBEAN IS FAIRLY CLEAR AT THIS TIME. A
SECOND TROPICAL WAVE IS IMPACTING THE EASTERN CARIBBEAN
SUPPORTING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM EAST OF
64W. ALOFT...A BROAD UPPER RIDGE COVERS THE MAJORITY OF THE
BASIN EAST OF THE UPPER TROUGH. TRADEWIND FLOW OF 15-20 KT IS
PRESENT THROUGHOUT MUCH OF THE AREA REACHING 25 KT NEAR THE
COAST OF COLOMBIA. EXPECT THE WAVE IN THE SW CARIBBEAN TO DRIFT
WESTWARD WITH MOISTURE LIKELY TO REMAIN NEAR CENTRAL AMERICA.
THE TROPICAL WAVE IN THE EASTERN CARIBBEAN WILL CONTINUE
WESTWARD AS WELL BRINGING MOISTURE INTO THE CENTRAL CARIBBEAN.

HISPANIOLA...
A CLUSTER OF HEAVY SHOWERS/THUNDERSTORMS IS CURRENTLY OVER HAITI
FROM 18N-19N BETWEEN 71W-72W. THIS ACTIVITY IS MOSTLY TIED TO
DAYTIME HEATING AND INSTABILITY PRESENT ON MOST AFTERNOONS.
THERE IS AN UPPER TROUGH TO THE EAST...BUT IT LIKELY IS NOT
INFLUENCING THE ACTIVITY OVER THE ISLAND YET. A TROPICAL WAVE IN
THE EASTERN CARIBBEAN IS MOVING WEST AND WILL BEGIN TO BRING
EXTRA MOISTURE TO HISPANIOLA TOMORROW AFTERNOON THROUGH THE
WEEKEND. AT THE SAME TIME THE UPPER TROUGH TO THE WEST WILL MOVE
EAST AND LIKELY ENHANCE ACTIVITY NEAR THE WAVE. THIS COMBINATION
COULD MEAN MORE THAN AVERAGE RAINFALL OVER HISPANIOLA.

THE ATLANTIC OCEAN...
SCATTERED SHOWERS/THUNDERSTORMS ARE OVER THE BAHAMAS SOUTH OF
28N WEST OF 72W ASSOCIATED WITH AN UPPER LEVEL LOW OVER THE
FLORIDA KEYS. THE REMAINDER OF THE AREA IS DOMINATED BY ONE
LARGE AND BROAD SURFACE RIDGE ANCHORED BY A 1028 MB HIGH NEAR
30N41W. ALOFT...UPPER RIDGING COVERS THE WEST AND CENTRAL ATLC.
AN UPPER LEVEL TROUGH IS ALONG 41W SUPPORTING A FEW UPPER LEVEL
CLOUDS TO THE EAST. A SECOND UPPER RIDGE AXIS IS ALONG 30W
FOLLOWED BY AN UPPER LEVEL TROUGH OVER NW AFRICAN. THE LAST
VISIBLE SATELLITE IMAGES OF THE DAY INDICATE A LARGE AREA OF
SAHARAN DUST EXTENDS OFF THE COAST OF AFRICA AND CONTINUES TO
NEAR 53W.

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

$$
WALTON

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