[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 281106
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT JUN 28 2014

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...

ATLANTIC TROPICAL WAVE ALONG 39W SOUTH OF 15N IS MOVING QUICKLY
WESTWARD NEAR 25 KT DUE TO EASTERLY JET SOUTH OF THE SUBTROPICAL
HIGH. THE WAVE IS MOVING THROUGH A DRY ENVIRONMENT ASSOCIATED TO
SAHARAN AIR COMBINED WITH SUBSIDENT AIR EAST OF THE SUBTROPICAL
HIGH. CONVECTION IS WEST OF THE WAVE AXIS...WITH SHOWERS NOTED
FROM 06N TO 09N BETWEEN 39W AND 46W IN THE VICINITY OF THE ITCZ.

ATLANTIC TROPICAL WAVE ALONG 51W SOUTH OF 16N...MOVING WESTWARD
AT 15 KT. CONVERGENCE ASSOCIATED TO THIS WAVE IS OCCURRING EAST
OF THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS NOTED FROM 7N
TO 9N BETWEEN 47W AND 52W IN THE VICINITY OF THE ITCZ.

CARIBBEAN TROPICAL WAVE ALONG 68W SOUTH OF 17N...MOVING WESTWARD
AT 15 TO 20 KT. SCATTERED MODERATE CONVECTION IS NOTED IN THE
VICINITY OF THE WAVE AXIS CENTRAL CARIBBEAN AND SOUTH AMERICA.

CARIBBEAN TROPICAL WAVE ALONG 84W SOUTH OF 20N. ITS WESTWARD
PROGRESS HAS SLOWED AND IS MOVING AT 10 KT OR LESS. THERE IS
LIMITED CONVECTION ASSOCIATED TO THIS WAVE. PAPAGAYO GAP WIND
FLOW IS EXPECTED TO INCREASE DURING THE NEXT COUPLE OF DAYS AS
THE WAVE REACHES THE EASTERN NORTH PACIFIC.

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

THE MONSOON TROUGH EXTENDS FROM THE COAST OF SENEGAL NEAR 14N17W
TO 9N22W. ITCZ EXTENDS FROM 9N22W TO 6N47W TO THE COAST OF SOUTH
AMERICA NEAR 5N52W. SCATTERED MODERATE CONVECTION FROM 5N TO 10N
BETWEEN 36W AND 54W.

...DISCUSSION...

...THE GULF OF MEXICO...

AN UPPER LEVEL TROUGH EXTENDS ACROSS OKLAHOMA INTO WESTERN
TEXAS. UPPER LEVEL DIVERGENCE ASSOCIATED WITH A SHORT WAVE
TROUGH MOVING ACROSS LOUISIANA. AN UPPER LEVEL ANTICYCLONE IS
EAST OF THE TROUGH CENTERED OVER NORTHERN FLORIDA. WEAK 1020 MB
HIGH IS CENTERED OVER THE NE GULF OF MEXICO NEAR 29N85W WITH A
RIDGE EXTENDING SE ACROSS FLORIDA. SHOWERS ARE MINIMAL ACROSS
THE ENTIRE BASIN THIS MORNING.

...THE CARIBBEAN SEA...

BROAD UPPER LEVEL CYCLONIC FLOW PREVAILS ACROSS THE CARIBBEAN
BASIN WITH UPPER LEVEL TROUGHING NOTED IN THE WESTERN CARIBBEAN.
DRY SAHARA-SOURCE AIR MASS CONTINUES OVER THE AREA CHARACTERIZED
BY A STABLE ENVIRONMENT. SHALLOW TRADE WIND CUMULUS...WITH FEW
SHOWERS PREVAIL OVER MUCH OF THE WATERS. CONVECTION IN THE SW
CARIBBEAN IS BEING ENHANCED BY INTERACTION OF THE MONSOON TROUGH
WITH THE SOUTHERN EXTENT OF TROPICAL WAVE MOVING ACROSS WESTERN
WATERS OUTSIDE THE USUAL REACH OF THE SAHARAN AIR MASS. THE
PRESSURE GRADIENT BETWEEN THE ATLANTIC RIDGE AND THE MONSOON
TROUGH IS MAINTAINING 20-25 KT TRADES IN THE CENTRAL CARIBBEAN
AND 10-20 KT WINDS IN BOTH THE WESTERN AND EASTERN CARIBBEAN.

...HISPANIOLA...

THE DIURNAL CYCLE OF DAYTIME HEATING AND ASSOCIATED CONVECTION
CONTINUES TO WEAKEN OVER HISPANIOLA. SAHARAN AIR MASS WILL MOVE
OVER HISPANIOLA OVER THE NEXT COUPLE OF DAYS AND DEVELOPMENT OF
AFTERNOON CONVECTION SHOULD BE DELAYED...WITH GENERALLY LESS
COVERAGE THAN IS TYPICALLY EXPECTED DURING THE SUMMER MONTHS.

...THE ATLANTIC OCEAN...

UPPER LEVEL TROUGH EXTENDS FROM AN UPPER LEVEL LOW NEAR 30N50W
SOUTHWESTWARD ACROSS THE WESTERN ATLANTIC AND CUBA INTO THE WEST
CENTRAL CARIBBEAN. SUBSIDENCE EAST OF THIS FEATURE IS HELPING TO
MAINTAIN THE EASTERN ATLANTIC SUBTROPICAL HIGH CENTERED NEAR
33N41W. A SURFACE RIDGE EXTENDS WSW OF THE HIGH ALL ACROSS THE
WESTERN ATLANTIC ROUGHLY ALONG 27/28N. A DRY AIRMASS ASSOCIATED
WITH A SAHARAN DUST OUTBREAK SEVERAL DAYS AGO PREVAILS OVER THE
TROPICAL ATLANTIC WATERS. SUBSIDENT AIR ON THE EASTERN SIDE OF
THE SUBTROPICAL HIGH IS LIMITING DEEP CONVECTION TO THE ITCZ AND
SOUTHERN EXTENT OF THE TROPICAL WAVES MENTIONED ABOVE. WINDS
OVER THE SW N ATLC WATERS W OF 65W ARE VERY LIGHT IN THE 5-10 KT
RANGE OVER MUCH OF THE AREA EXCEPT S OF 22N WHERE WINDS ARE 10
TO 15 KT. TRADE WINDS IN TROPICAL ATLANTIC WATERS ARE 15-20 KT.

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

$$
MUNDELL


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