000
AXNT20 KNHC 290611 CCA
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN JUN 29 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...SPECIAL FEATURES...                                          

A LOW LOCATED ABOUT 160 NM E OF JACKSONVILLE FLORIDA NEAR 31N78W 
IS PRODUCING SCATTERED MODERATE TO HEAVY SHOWERS AND ISOLATED 
THUNDERSTORMS IN BANDS SOUTH OF THE LOW CENTER. ENVIRONMENTAL 
CONDITIONS ARE FAVORABLE FOR ADDITIONAL DEVELOPMENT AS THIS 
SYSTEM DRIFTS SOUTHWARD DURING THE NEXT FEW DAYS. THERE IS A 
MEDIUM PROBABILITY THIS SYSTEM WILL BECOME A TROPICAL CYCLONE 
WITHIN 48 HOURS. PLEASE REFER TO THE ATLC TROPICAL WEATHER 
OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOAT/ABNT20 KNHC FOR MORE 
DETAILS.

...TROPICAL WAVES... 

TROPICAL WAVE N OF THE ITCZ WITH AXIS EXTENDING FROM 18N41W TO 
7N45W MOVING WEST AT 20 KT. SAHARAN AIR LAYER TRACKING IMAGERY 
INDICATE THE PRESENCE OF DRY AIR N OF THE ITCZ WHICH IS LIMITING 
THE CONVECTION TO A FEW SHOWERS WITHIN 180 NM N OF THE ITCZ. 

TROPICAL WAVE IS W OF THE ITCZ WITH AXIS EXTENDING FROM 18N57W 
TO 7N58W MOVING WEST AT 15-20 KT. SAHARAN AIR LAYER TRACKING 
IMAGERY SHOW DRY AIR IN THE WAVE ENVIRONMENT N OF 10N. MINIMAL 
SHOWER ACTIVITY.

TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN WITH AXIS EXTENDING 
FROM 20N74W TO THE COLOMBIAN COAST AT 75W MOVING WEST AT 15 KT. 
SSMI TPW IMAGERY SHOW DRY AIR IN THE NORTHERN PART OF THE WAVE 
WHICH ALONG WITH STRONG DEEP-LAYER WIND SHEAR HINDERS DEEP 
CONVECTION. SCATTERED TRADE WIND SHOWERS ARE WITHIN 180 NM 
EITHER SIDE OF THE AXIS S OF 15N.

TROPICAL WAVE OVER THE W BAY OF CAMPECHE WITH AXIS EXTENDING 
FROM 21N95W TO 13N96W MOVING WEST AT 15 KT. THIS WAVE IS WEAK 
AND BARELY DISCERNIBLE AS IT MOVES IN THE W-SW PERIPHERY OF A 
LOW LEVEL RIDGE. CONVECTION ASSOCIATED WITH THIS WAVE IS 
CONFINED TO THE EAST PACIFIC BASIN. 

...THE ITCZ/THE MONSOON TROUGH...                                
     
THE MONSOON TROUGH EXTENDS FROM THE SENEGAL COAST OF AFRICA NEAR 
13N17W TO 7N24W. ITCZ BEGINS NEAR 7N25W AND CONTINUES TO 6N55W. 
SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 5N-9N 
E OF 30W WITHIN 120 NM EITHER SIDE OF THE ITCZ. 

...DISCUSSION...

...THE GULF OF MEXICO...                                     

SURFACE RIDGING DOMINATES ACROSS THE GULF BEING SUPPORTED BY A 
MIDDLE LEVEL ANTICYCLONE COVERING THE EASTERN HALF OF THE BASIN. 
THE SURFACE RIDGE IS ANCHORED BY 1022 MB HIGH NEAR 29N86W...AND 
SUPPORTING 10-15 KT E TO SE WINDS...EXCEPT W OF 92W WHERE WINDS 
ARE UP TO 20 KT. A NEGATIVELY TILTED UPPER LEVEL TROUGH EXTENDS 
FROM OKLAHOMA THROUGH EASTERN TEXAS TO THE NW GULF WHILE EASTERN 
PERIPHERY OF A RIDGE ANCHORED OVER SW MEXICO COVERS THE BAY OF 
CAMPECHE. THE PRESENCE OF DRY AIR ALOFT IS HINDERING DEVELOPMENT 
OF CONVECTION IN THE AREA. HIGH PRESSURE WILL PREVAIL ACROSS THE 
BASIN THE NEXT COUPLE OF DAYS.

...THE CARIBBEAN SEA...                                       

AN UPPER LEVEL CYCLONE IS NEAR 20N83W. MODERATE SUBSIDENCE IS 
INDICATED OVER NW CARIBBEAN NEAR THE UPPER LOW. BROAD SUBSIDENCE 
AND THE PRESENCE OF SAHARAN DUST IS KEEPING MOST OF THE BASIN 
UNDER FAIR BUT HAZY CONDITIONS. AT THE SURFACE...A TROUGH IS W 
OF THE WINDWARD ISLANDS WITH AXIS EXTENDING FROM 17N64W TO 
12N67W GENERATING SCATTERED SHOWERS AND THUNDERSTORMS FROM 13N 
TO 16N E OF 68W. 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. A SECOND TROPICAL WAVE WILL BE REACH THE E 
CARIBBEAN LATE TONIGHT. 

...HISPANIOLA...             

THE PRESENCE OF SAHARAN DRY AIR INHIBITED CONVECTION IN THE AREA 
INHIBITED CONVECTION DURING THE DAY. THE CONTINUED PRESENCE OF 
THE SAHARAN AIR LAYER IN THE AREA THE NEXT FEW DAYS SHOULD 
RESULT IN DELAYED DEVELOPMENT OF AFTERNOON CONVECTION WITH 
GENERALLY LESS COVERAGE THAN TYPICALLY EXPECTED.  

...THE ATLANTIC OCEAN...

AN UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION NEAR 
32N48W SOUTHWESTWARD THROUGH 23N60W TO THE WINDWARD PASSAGE. 
MODERATE SUBSIDENCE WAS NOTED WITHIN 240 NM SE OF THE TROUGH 
AXIS. AN UPPER LEVEL ANTICYCLONE OVER NE FLORIDA DOMINATES THE 
FLOW OVER THE ATLANTIC W OF 73W. AREA OF LOW PRESSURE SUPPORTING 
SCATTERED MODERATE TO HEAVY SHOWERS AND ISOLATED THUNDERSTORMS 
IN BANDS E OF JACKSONVILLE FL. REFER TO THE SPECIAL FEATURES 
SECTION FOR MORE INFORMATION. ELSEWHERE...A BROAD SURFACE RIDGE 
ANCHORED BY A 1030 MB HIGH NEAR 33N40W EXTENDED THROUGH 28N55W 
TO THE BAHAMAS SUPPORTS GENERALLY FAIR WEATHER CONDITIONS. 

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

$$
MUNDELL