000
AXNT20 KNHC 291046
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1015 UTC.

...SPECIAL FEATURES...                                          

A LOW LOCATED ABOUT 180 NM E OF JACKSONVILLE FLORIDA NEAR 30N77W 
IS PRODUCING SCATTERED MODERATE TO HEAVY SHOWERS AND ISOLATED 
THUNDERSTORMS IN BANDS SE 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 18N42W TO 
7N47W 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 120 NM N OF THE ITCZ. 

TROPICAL WAVE IS W OF THE ITCZ WITH AXIS EXTENDING FROM 18N58W 
TO 7N589W 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 19N76W TO 10N77W 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 E OF THE AXIS S OF 14N.

TROPICAL WAVE MOVING INTO VERACRUZ COAST OF MEXICO WITH AXIS 
EXTENDING FROM 21N96W TO 13N97W 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 AND SOUTHERN MEXICO. 

...THE ITCZ/THE MONSOON TROUGH...                                
     
THE MONSOON TROUGH EXTENDS FROM THE GUINEA COAST OF AFRICA NEAR 
11N15W TO 7N24W. ITCZ BEGINS NEAR 7N24W AND CONTINUES TO 6N55W. 
SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 4N-8N 
E OF 40W WITHIN 120 NM EITHER SIDE OF THE BOUNDARY. 

...DISCUSSION...

...THE GULF OF MEXICO...                                     

SURFACE RIDGING ACROSS THE GULF IS BEING SUPPORTED BY A MIDDLE 
LEVEL ANTICYCLONE COVERING THE EASTERN HALF OF THE BASIN. THE 
SURFACE RIDGE IS ANCHORED BY 1020 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. 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 1028 MB HIGH NEAR 34N42W EXTENDED THROUGH 28N55W 
TO THE BAHAMAS SUPPORTS GENERALLY FAIR WEATHER CONDITIONS. 

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

$$
MUNDELL