Atlantic Tropical Weather Discussion

000
AXNT20 KNHC 181801
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
205 PM EDT TUE JUN 18 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURE...                                     
TROPICAL DEPRESSION TWO CENTER LOCATED NEAR NEAR 17.9N 90.0W AT 
18/1500Z AND MOVING W-NW AT 7 KT. THE ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 1009 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 25 
KNOTS WITH GUSTS TO 35 KNOTS. SCATTERED MODERATE CONVECTION IS 
OVER THE YUCATAN PENINSULA AS WELL AS PORTIONS OF BELIZE WITH 
ISOLATED SHOWERS ALREADY REACHING THE BAY OF CAMPECHE. THE 
CENTER OF THE DEPRESSION WILL BE MOVING OVER THE SOUTHERN BAY OF 
CAMPECHE ON WEDNESDAY AND THURSDAY. THIS SYSTEM IS EXPECTED TO 
PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 3 TO 5 INCHES WITH 
MAXIMUM AMOUNTS OF 10 INCHES ACROSS PORTIONS OF 
BELIZE...GUATEMALA...THE YUCATAN PENINSULA AND SOUTHERN MEXICO. 
THESE RAINS COULD CAUSE LIFE THREATENING FLASH FLOODING AND 
MUDSLIDES...ESPECIALLY IN MOUNTAINOUS AREAS. PLEASE READ THE 
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/ WMO HEADERS 
MIATCMAT2/WTNT22 KNHC AND THE PUBLIC ADVISORY UNDER 
MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. PLEASE REMEMBER ALSO 
THAT FORECAST WINDS IN AND NEAR ACTIVE TROPICAL CYCLONES SHOULD 
BE USED WITH CAUTION DUE TO UNCERTAINTY IN FORECAST 
TRACK...SIZE...AND INTENSITY.

...TROPICAL WAVES...                                             
A TROPICAL WAVE IS OVER THE EASTERN ATLC WITH AXIS EXTENDING 
FROM 12N24W TO 03N22W AND MOVING WEST AT 15-20 KT. THE METEOSAT-
9 SAL TRACKING PRODUCT SHOWS MODERATE DRY AIR ENGULFING THE N-NW 
PORTIONS OF THE AXIS. HOWEVER...THE PSEUDO NATURAL COLOR IMAGERY 
SHOW THAT A DUST OUTBREAK IS SPREADING OVER THE WAVE 
ENVIRONMENT...ESPECIALLY TO THE WAVE PORTION N OF THE MONSOON 
TROUGH AXIS WHERE DENSER BROWNISH HAZE IS OBSERVED. THE WARM AND 
DRY AIR SURROUNDING THIS WAVE IS LIMITING CONVECTION.

A TROPICAL WAVE IS ACROSS THE SE CARIBBEAN INTO VENEZUELA WITH 
AXIS ALONG 14N66W TO 06N66W AND IT IS MOVING WEST AT 10-15 KT. 
OVERALL MODERATE DEEP LAYER MOISTURE IS WITHIN THE WAVE 
ENVIRONMENT AND NO CONVECTION IS ASSOCIATED WITH IT AT THIS 
TIME. 

...THE ITCZ/THE MONSOON TROUGH...                             
THE MONSOON TROUGH PASSES THROUGH THE COASTAL OF AFRICA NEAR 
10N14W TO 07N21W 05N28W. THE ITCZ CONTINUES FROM 05N28W TO 
05N37W 05N45W. SCATTERED MODERATE CONVECTION IS FROM 05N-10N 
EAST OF 23W AS WELL AS FROM 04N-07N BETWEEN 39W-43W.

...DISCUSSION...

THE GULF OF MEXICO...                                         
THE AZORES HIGH EXTENDS A RIDGE SW TO THE GULF WHICH IS 
PROVIDING RETURN FLOW OF 10-15 KT ACROSS THE BASIN. THE TROPICAL 
DEPRESSION TWO WITH CENTER CURRENTLY JUST N OF GUATEMALA IN THE 
YUCATAN PENINSULA IS ADVECTING MOISTURE TO THE SE GULF AS WELL 
AS THE BAY OF CAMPECHE. CONTINUOUS MODERATE RAINFALL ASSOCIATED 
TO THIS SYSTEM HAS CAUSED SIGNIFICANT FLOODING ACROSS 
BELIZE...GUATEMALA...AND THE YUCATAN PENINSULA WITH 
ACCUMULATIONS OF 3 TO 5 INCHES AND MAXIMUM AMOUNTS OF 10 INCHES. 
THIS SYSTEM IS EXPECTED TO CONTINUE A W-NW TRACK AND MOVE OVER 
THE BAY OF CAMPECHE WEDNESDAY AND THURSDAY. MODEL GUIDANCE 
INDICATES RAINFALL ACCUMULATIONS UP TO 4 INCHES THROUGH THURSDAY 
S OF 25N WEST OF 91W. WHILE THE SYSTEM EMERGES TO THE BAY OF 
CAMPECHE A HIGH PRESSURE CENTER IS EXPECTED TO BUILD NE OF THE 
BASIN WHICH WILL PERSIST THROUGH THURSDAY AFTERNOON. 
OTHERWISE...N OF 24N AND ACROSS THE GULF DRY AIR AT THE SURFACE 
AND MIDDLE TO UPPER LEVELS IS KEEPING FAIR WEATHER.

THE CARIBBEAN SEA...                                             
DEEP LAYER HIGH MOISTURE ASSOCIATED WITH THE TROPICAL DEPRESSION 
TWO CURRENTLY JUST N OF GUATEMALA CONTINUES GENERATING SCATTERED 
MODERATE SHOWERS OVER THE WESTERN CARIBBEAN W OF 85W. 
SIMILARLY...DEEP LAYER HIGH MOISTURE ASSOCIATED WITH THE MONSOON 
TROUGH AXIS IS ENHANCING CLUSTERS OF MODERATE/ISOLATED STRONG 
CONVECTION IN THE SOUTHERN CARIBBEAN...WITHIN 100 NM N OF THE 
PANAMA COASTLINE BETWEEN 79W-82W. A TROPICAL WAVE AXIS EXTENDS 
OVER A PORTION OF THE SE CARIBBEAN INTO VENEZUELA. ITS AXIS IS 
ALONG 14N66W TO 06N66W AND CURRENTLY THERE IS NO CONVECTION 
ASSOCIATED TO IT. NUMEROUS MODERATE CONVECTION WITH ISOLATED 
THUNDERSTORMS SPREADS OVER THE LESSER ANTILLES S OF 15N EAST OF 
65W. A COMBINATION OF HIGH DEEP LAYER MOISTURE OBSERVED IN THE 
TOTAL PRECIPITABLE WATER IMAGERY...20 KT TRADEWINDS AND UPPER 
LEVEL DIFFLUENCE FROM A LOW N OF PUERTO RICO AND RIDGING TO THE 
WEST AND EAST OF THE ISLANDS IS ENHANCING THE CONVECTION. THE 
WAVE WILL CONTINUE A WESTWARD TRACK AND WILL BE ALONG COLOMBIA 
IN 24 HOURS AND OVER THE SOUTHERN CARIBBEAN BY THURSDAY 
AFTERNOON. TRADEWINDS WILL CONTINUE DURING THIS PERIOD.

HISPANIOLA...                                             
CURRENTLY VERY DRY AIR OVER LA HISPANIOLA...WITH ONLY ISOLATED 
SHOWERS OVER HAITI. AN UPPER LEVEL LOW AS WELL AS LOW MOISTURE 
FROM THE SURFACE TO THE MIDDLE LEVELS WILL KEEP MOSTLY FAIR 
WEATHER THROUGH LATE WEDNESDAY EXCEPT IN THE AFTERNOON WHERE 
SURFACE HEATING COULD INDUCE SOME SHOWERS. HOWEVER...AS THE 
TROPICAL WAVE MOVES WESTWARD TO THE SOUTHERN CARIBBEAN BY 
THURSDAY...MOISTURE WILL BE CARRIED OUT TO LA HISPANIOLA AND 
PUERTO RICO WHICH WILL ENHANCE RAINSHOWERS.

THE ATLANTIC OCEAN...                                            
A WEAK SURFACE TROUGH IS OVER THE WEST ATLC EXTENDING ALONG 
30N63W TO 24N67W WITH NO CONVECTION ASSOCIATED TO IT. 
OTHERWISE...BROAD SURFACE RIDGING FROM THE AZORES HIGH CENTERED 
NEAR 38N30W SPREADS OVER THE ENTIRE BASIN N OF 14N. DEEP LAYER 
DRY AIR IS KEEPING FAIR WEATHER ACROSS THE BASIN.  


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

$$
RAMOS