[Tropical] Tropical Weather Discussion

[EMWIN Server]

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


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