[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 132337
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT JUN 13 2015

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
2315 UTC.

...SPECIAL FEATURES...

A BROAD AREA OF LOW PRESSURE IS CENTERED OVER THE YUCATAN
PENINSULA AND IS PRODUCING A LARGE AREA OF SHOWERS AND
THUNDERSTORMS AND WINDS TO NEAR GALE FORCE OVER THE NW CARIBBEAN
AND SE GULF OF MEXICO. ENVIRONMENTAL CONDITIONS SHOULD SUPPORT
SOME DEVELOPMENT OF THIS SYSTEM WHEN IT MOVES OVER THE
SOUTHWESTERN GULF OF MEXICO BY SUNDAY NIGHT AND THE NORTHWESTERN
GULF OF MEXICO THROUGH TUESDAY. REGARDLESS OF
DEVELOPMENT...HEAVY RAINS ARE POSSIBLE OVER THE YUCATAN
PENINSULA DURING THE NEXT FEW DAYS. ADDITIONAL INFORMATION ON
THIS SYSTEM CAN BE FOUND IN THE HIGH SEAS FORECAST PRODUCT UNDER
WMO FZNT02 KNHC OR MIAHSFAT2. THE CHANCES OF THIS SYSTEM
DEVELOPING INTO A TROPICAL CYCLONE OVER THE NEXT 48 HOURS IS
MEDIUM.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE EXTENDS FROM 15N36W TO 05N37W.
THIS WAVE IS MOVING W AT 20 KT. MODEL GUIDANCE DEPICTS A 700 MB
TROUGH IN THE ENVIRONMENT OF THIS WAVE. DESPITE THAT TPW SSMI
IMAGERY SHOWS A MOIST ENVIRONMENT PREVAILING FROM 04N-
14N...THERE IS NO SIGNIFICANT CONVECTION RELATED TO THIS WAVE AS
STRONG DEEP LAYER WIND SHEAR DOMINATES THE REGION INHIBITING
CONVECTION AND SAHARAN DUST IS PRESENT OVER THE NORTHERN HALF OF
THE WAVE.

AN ATLANTIC OCEAN TROPICAL WAVE EXTENDS FROM 14N46W TO 05N48W.
THIS WAVE IS MOVING W AT 20 KT. SAHARAN DUST IS ALSO NOTED ALONG
THE NORTHERN HALF OF THIS WAVE WHICH IS INHIBITING SIGNIFICANT
CONVECTION OVER THIS AREA MAINLY N OF 09N. ISOLATED MODERATE
CONVECTION IS DEPICTED S OF 09N BETWEEN 45W-48W.

A E CARIBBEAN TROPICAL WAVE EXTENDS FROM 18N71W TO 09N71W. THIS
WAVE IS MOVING W AT 20 KT. TOTAL PRECIPITABLE WATER VAPOR
IMAGERY SHOWS THIS WAVE EMBEDDED IN RELATIVELY DRY AIR. THERE IS
ALSO A BROAD SAHARAN AIRMASS PREVAILING ACROSS THE EASTERN
CARIBBEAN INHIBITING ANY CONVECTION.

A W CARIBBEAN TROPICAL WAVE EXTENDS FROM 13N82W TO 05N82W. THIS
WAVE IS MOVING W AT 20 KT. TPW IMAGERY DEPICTS A DEEP MOIST
ENVIRONMENT ALONG THIS WAVE. SCATTERED MODERATE CONVECTION IS S
OF 09N AFFECTING PANAMA AND THE EPAC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH COASTAL SECTIONS OF AFRICA
NEAR 11N16W TO 07N23W WHERE THE ITCZ BEGINS AND CONTINUES TO
07N35W. THE ITCZ THEN RESUMES W OF A TROPICAL WAVE NEAR 07N39W
TO 05N47W. ISOLATED MODERATE CONVECTION IS WITHIN 100 NM N OF
THE ITCZ AXIS.

...DISCUSSION...

THE GULF OF MEXICO...

A PAIR OF UPPER-LEVEL LOW CENTERS CONTINUE OVER THE GULF...ONE
LOCATED NEAR 23N90W AND THE OTHER NEAR 30N86W. A DIFFLUENT FLOW
PREVAILS ACROSS THE NW GULF SUPPORTING ISOLATED CONVECTION N OF
26N AND W OF 91W. ANOTHER AREA OF UPPER-LEVEL DIFFLUENCE
PREVAILS ACROSS THE SE HALF OF THE BASIN SUPPORTING SCATTERED
MODERATE CONVECTION S OF 25N AND E OF 89W. THIS CONVECTION IS
ALSO RELATED TO THE PROXIMITY OF AN AREA OF LOW PRESSURE
CURRENTLY LOCATED OVER THE YUCATAN PENINSULA AND NORTHERN BELIZE
CENTERED NEAR 18N88W. FOR MORE INFORMATION ABOUT THIS...PLEASE
REFER TO THE SPECIAL FEATURES SECTION ABOVE. AT THE SURFACE...A
BROAD AREA OF HIGH PRESSURE CONTINUES OVER THE ATLANTIC AND
EXTENDS W REACHING THE GULF WATERS. WITH THIS...A GENTLE TO
MODERATE ANTICYCLONIC FLOW PREVAILS ACROSS THE BASIN. EXPECT
OVER THE NEXT 24 HOURS FOR THE CONVECTION ASSOCIATED WITH THE
BROAD AREA OF LOW PRESSURE TO SPREAD INTO THE S-CENTRAL GULF.

THE CARIBBEAN SEA...

TWO TROPICAL WAVES ARE OVER THE CARIBBEAN...FOR MORE INFORMATION
PLEASE REFER TO THE SECTION ABOVE. AN AREA OF UPPER LEVEL
DIFFLUENCE EXTENDS FROM THE GULF ACROSS THE W CARIBBEAN
SUPPORTING SCATTERED MODERATE CONVECTION MAINLY W OF 80W
AFFECTING CUBA AND CENTRAL AMERICA. AN AREA OF LOW PRESSURE IS
DEVELOPING OVER THE YUCATAN PENINSULA AND IT IS ALSO SUPPORTING
THIS CONVECTION. FOR MORE INFORMATION ABOUT THIS LOW PLEASE
REFER TO THE SPECIAL FEATURES SECTION ABOVE. THE REMAINDER OF
THE BASIN IS UNDER THE INFLUENCE OF AN UPPER-LEVEL ANTICYCLONE
CENTERED OVER THE EPAC AND EXTENDING ACROSS THE CARIBBEAN. THE
SURFACE HIGH THAT PREVAILS ACROSS THE ATLANTIC ALSO EXTENDS SW
REACHING THE CARIBBEAN. THE E HALF OF THE BASIN IS UNDER THE
INFLUENCE OF A SAHARAN AIRMASS WHICH IS INHIBITING SIGNIFICANT
CONVECTION MAINLY E OF 75W. SCATTEROMETER DATA DEPICTS GENTLE TO
MODERATE TRADES ACROSS THE BASIN EXCEPT S OF 18N BETWEEN 70W-81W
WHERE MODERATE TO FRESH WINDS PREVAIL. OVER THE NEXT 24
HOURS...EXPECT CONVECTION TO PREVAIL ACROSS THE W CARIBBEAN
WHILE THE E WILL REMAIN DRY.

...HISPANIOLA...

ISOLATED SHOWERS AND THUNDERSTORMS ARE OCCURRING OVER THE
ISLAND. THIS ACTIVITY IS EXPECTED TO DIMINISH DURING THE
EVENING. SIMILAR ACTIVITY IS EXPECTED OVER THE NEXT 24 HOURS.

THE ATLANTIC OCEAN...

FAIR WEATHER PREVAILS ACROSS THE WHOLE BASIN. AN UPPER-LEVEL LOW
IS REFLECTED AT THE SURFACE BY A TROUGH CURRENTLY EXTENDING FROM
28N46W TO 31N60W. NO SIGNIFICANT CONVECTION IS RELATED TO THIS
FEATURE. A BROAD AREA OF HIGH PRESSURE PREVAILS ACROSS THE BASIN
CENTERED NEAR 28N53W. A WEAK SURFACE LOW IS OBSERVED ON
SATELLITE IMAGERY CENTERED NEAR 26N42W. THIS LOW HAS NO
CONVECTION ASSOCIATED TO IT. EXPECT A SIMILAR WEATHER REGIME TO
PERSIST OVER THE NEXT 24 HOURS.

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

$$

ERA
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