[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201739
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI JUN 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE HAS MOVED OUT OF AFRICA AND EXTENDS FROM 15N17W
TO 6N16W. THE HOVMOLLER DIAGRAM CLEARLY INDICATES THE WESTWARD
PROPAGATION OF THE WAVE ACROSS AFRICA INTO THE TROPICAL ATLC
OCEAN. SCATTERED MODERATE CONVECTION IS NOTED WHERE THE WAVE
MEETS THE MONSOON TROUGH. THE WAVE WILL CONTINUE TO MOVE
WESTWARD AT ABOUT 15 KT.

THE TROPICAL WAVE PREVIOUSLY LOCATED ALONG 32W IS RELOCATED
FARTHER EAST BASED ON VISIBLE SATELLITE IMAGERY AND A PAIR OF
SURFACE OBSERVATIONS. THE WAVE CURRENTLY EXTENDS FROM 11N27W TO
5N28W. A CYCLONIC TURNING IS NOTED ALONG THE WAVE AXIS NEAR
7N28W. IN ADDITION...THE 1110 UTC ASCAT PASS INDICATES SOME WIND
SHIFT IN ASSOCIATION WITH THIS FEATURE. THE WAVE WILL CONTINUE
TO MOVE WESTWARD AT ABOUT 15 KT.

A TROPICAL WAVE IS CURRENTLY MOVING ACROSS THE EASTERN CARIBBEAN
AND EXTENDS FROM WESTERN PUERTO RICO TO NORTH-CENTRAL VENEZUELA
NEAR 8N67W. THE SAN JUAN DOPPLER RADAR SHOWS SOME SHOWER
ACTIVITY MOVING MAINLY ACROSS THE EAST PART OF THE INLAND IN A
SE WIND FLOW BEHIND THE WAVE AXIS. MODERATE CONVECTION IS ALSO
NOTED NEAR THE SOUTHERN END OF THE WAVE AXIS OVER VENEZUELA...
PARTICULARLY N OF 8N BETWEEN 66W AND 70W. THE WAVE IS
ACCOMPANIED BY A SURGE OF MOISTURE AS SEEN IN THE TOTAL
PRECIPITABLE WATER IMAGERY. THE WAVE IS FORECAST TO MOVE ACROSS
HISPANIOLA TONIGHT INTO SATURDAY. THIS SHOULD PROMOTE SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS.

A TROPICAL WAVE IS MOVING ACROSS SE MEXICO AND EXTENDS FROM
19N93W TO 12N95W. THE WAVE IS GENERATING SOME SHOWER ACTIVITY IN
THE GULF OF TEHUANTEPEC AND COINCIDES WITH A BULGE A MOISTURE AS
OBSERVED IN THE TOTAL PRECIPITABLE WATER ANIMATION. FOR FURTHER
INFORMATION ABOUT THIS WAVE PLEASE SEE THE TROPICAL WEATHER
DISCUSSION FOR THE EPAC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH ENTERS THE ATLANTIC ALONG THE COAST OF GUINEA
NEAR 9N14W THEN CONTINUES TO 07N26W. THE INTERTROPICAL
CONVERGENCE ZONE AXIS EXTENDS FROM 06N30W TO 02N40W TO 1N50W AT
THE COAST OF BRAZIL. SCATTERED MODERATE CONVECTION IS FROM 5N-9N
BETWEEN 12W-25W. SIMILAR CONVECTION IS ALSO NOTED WITHIN 150 NM
N OF AXIS BETWEEN 30W-33W.

...DISCUSSION...

GULF OF MEXICO...
A MOSTLY DRY AND STABLE ATMOSPHERE CONTINUES TO DOMINATE THE
GULF REGION UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A
HIGH PRES OF 1020 MB LOCATED OVER THE SE CONUS. VISIBLE SATELLITE
IMAGERY SUGGESTS THE PRESENCE OF SAHARAN DUST OVER THE GULF
WATERS MAINLY S OF 25N CREATING HAZY CONDITIONS. IN ADDITION...
THE 1200 UTC VERACRUZ SOUNDING ALSO SHOWS THE INVERSION
ASSOCIATED WITH THE DUST. A TROPICAL WAVE IS MOVING ACROSS THE
FAR SOUTHERN BAY OF CAMPECHE AND SE MEXICO. ALOFT...CONDITIONS
HAVE CHANGED LITTLE OVER THE PAST 24 HOURS. AN UPPER LEVEL
NORTHERLY FLOW IS ACROSS MOST OF THE GULF REGION BETWEEN A
MIDDLE TO UPPER LEVEL TROUGH OVER FLORIDA AND WESTERN CUBA AND
AN UPPER LEVEL RIDGE WITH AXIS ALONG THE COASTS OF MEXICO AND
TEXAS. WATER VAPOR IMAGERY INDICATES MOST OF THIS NORTHERLY FLOW
ALOFT REMAINS RELATIVELY DRY AND STABLE...PARTICULARLY BETWEEN
87W AND 94W. WEAK RIDGING SHOULD MEANDER TO NEAR THE CENTRAL
GULF DURING THE NEXT TWO DAYS AND GENERALLY DRY CONDITIONS WILL
PREVAIL. THIS SYSTEM WILL ALSO MAINTAIN GENERALLY LIGHT TO
MODERATE WINDS AND SLIGHT SEAS THROUGH THE WEEKEND.

CARIBBEAN SEA...
WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL TROUGH OVER THE NW
CARIBBEAN WITH AXIS EXTENDING FROM WESTERN CUBA AND THE ISLE OF
YOUTH TO THE GULF OF HONDURAS INTO NORTHERN CENTRAL AMERICA. A
RIDGE DOMINATES THE REMAINDER OF THE BASIN. ABUNDANT MID TO
UPPER LEVEL MOISTURE IS AHEAD OF THE TROUGH AXIS COVERING THE
MAJORITY OF THE CARIBBEAN SEA. VISIBLE SATELLITE IMAGERY SHOWS A
300 NM WIDE BAND OF MULTILAYERED CLOUDS WITH SPORADIC CONVECTION
EXTENDING FROM HONDURAS AND NICARAGUA ALL THE WAY NE TO OVER
EASTERN CUBA AND THE BAHAMAS. A TROPICAL WAVE IS MOVING ACROSS
THE EASTERN CARIBBEAN. PLEASE SEE TROPICAL WAVE SECTION FOR
DETAILS. ISOLATED TO SCATTERED MODERATE CONVECTION IS OBSERVED
OVER THE SW CARIBBEAN LIKELY ASSOCIATED WITH THE PROXIMITY OF
THE MONSOON TROUGH OVER PARTS OF PANAMA AND COSTA RICA. A
DIFFLUENT PATTERN ALOFT IS ALSO HELPING TO INDUCE THIS
CONVECTIVE ACTIVITY. PRES GRADIENT BETWEEN A RIDGE N OF AREA AND
THE COLOMBIAN/PANAMANIAN LOW WILL CONTINUE TO SUPPORT FRESH TO
STRONG TRADE WINDS ACROSS THE CENTRAL CARIBBEAN. FRESH TO
LOCALLY STRONG WINDS CONTINUE TO BLOW ACROSS THE GULF HONDURAS
MAINLY AT NIGHT.

...HISPANIOLA...
A TROPICAL WAVE OVER THE MONA PASSAGE THIS AFTERNOON WILL BRING
AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY TONIGHT AND
SATURDAY...ENHANCING THE DIURNAL LATE AFTERNOON-EARLY EVENING
MAXIMUM IN CONVECTION. MOISTURE IS ALREADY ON INCREASE ACROSS
THE ISLAND.

ATLANTIC OCEAN...
A WEAK AREA OF LOW PRES HAS DEVELOPED JUST OUT NE FLORIDA OR
ABOUT 80 MILES E-NE OF DAYTONA BEACH. A SWIRL OF LOW CLOUDS IS
ASSOCIATED THE LOW CENTER AND IS TOTALLY EXPOSED TO THE NORTH OF
SMALL AREA OF SHOWERS AND TSTMS. SURFACE PRES ARE RELATIVELY
HIGH IN THE REGION. CONDITIONS ARE EXPECTED TO REMAIN
UNFAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT WHILE THE
DISTURBANCE ACCELERATES NORTHEASTWARD. THE LATEST NHC WEATHER
OUTLOOK GIVES THIS LOW PRES AREA A LOW CHANCE OF DEVELOPING INTO
A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. A WEAK HIGH PRES OF
1021 MB IS CENTERED NEAR 28N71W. THIS FEATURE WILL DISSIPATE IN
ABOUT 24 HOURS. OTHERWISE...A SURFACE RIDGE DOMINATES THE
REMAINDER OF THE CENTRAL AND EAST ATLC WITH A PAIR OF 1024 MB
HIGH PRES CENTERS LOCATED NEAR 27N44W AND NEAR 28N32W. THESE
FEATURES WILL REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS.
MODERATE TO FRESH TRADE WINDS ARE SEEN ON THE SOUTHERN PERIPHERY
OF THE RIDGE. ALOFT...WATER VAPOR IMAGERY CONTINUES TO SHOW AN
UPPER LEVEL TROUGH OVER THE FLORIDA PENINSULA AND WESTERN CUBA.
SW FLOW AHEAD OF THE TROUGH IS ADVECTING MID/UPPER LEVEL
MOISTURE ACROSS EAST AND CENTRAL CUBA INTO THE BAHAMAS. TO THE
EAST...ANOTHER UPPER LEVEL LOW IS CENTERED NEAR 27.5N57W. A
TROUGH EXTENDS FROM THE LOW CENTER TO NEAR 21N60W. ANOTHER AREA
OF MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS IS NOTED AHEAD OF
THE TROUGH COVERING THE AREA FROM 17N-25N BETWEEN 54W-60W.
MOSTLY FAIR WEATHER PREVAILS ACROSS THE REMAINDER OF THE ATLC N
OF THE ITCZ/MONSOON TROUGH.

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

$$
GR

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