[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221026
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON JUL 22 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0952 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE IS OVER THE EAST TROPICAL ATLC WITH AXIS
EXTENDING FROM 18N20W TO 08N21W. IT IS EMBEDDED WITHIN A
MODERATE TO HIGH MOIST ENVIRONMENT AND ITS AXIS IS MOVING NEAR
10 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 07N-
14N E OF 23W. ISOLATED MODERATE CONVECTION IS WITHIN 170 NM W OF
THE AXIS S OF 18N.

A TROPICAL WAVE IS MOVING ACROSS THE LESSER ANTILLES WITH A
TILTED AXIS EXTENDING FROM 20N57W TO 13N64W AND MOVING NEAR 10
KT. THE WAVE AXIS IS EMBEDDED WITHIN A MOSTLY MODERATE MOIST
ENVIRONMENT WITH PATCHES OF HIGH MOISTURE LYING OVER THE LEEWARD
ISLANDS AND GRENADA. CONVECTIVE ACTIVITY HAS REDUCED TO
RAINSHOWERS COINCIDING WITH THE REGIONS OF HIGHER MOISTURE OVER
THE LEEWARD ISLANDS AND GRENADA. A SAL OUTBREAK SPREADS ACROSS
THE ATLC TO JUST E OF THE WAVE AXIS. SAL DRY AIR ENTRAINMENT TO
THE WAVE ENVIRONMENT IS HINDERING FURTHER CONVECTION AT THE
TIME.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE E
TROPICAL ATLC NEAR 14N17W AND CONTINUES ALONG 09N28W TO 07N35W.
THE ITCZ AXIS EXTENDS FROM 07N35W TO 05N43W 04N51W. BESIDES THE
CONVECTION ALREADY DISCUSSED ASSOCIATED WITH THE TROPICAL WAVE
NEAR WEST AFRICA...NUMEROUS MODERATE CONVECTION IS FROM 06N-10N
BETWEEN 26W-34W. ISOLATED MODERATE CONVECTION IS WITHIN 100 NM
EITHER SIDE OF THE ITCZ AXIS BETWEEN 39W-52W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE CENTERED OVER NEW MEXICO EXTENDS OVER THE
GULF W OF 89W WHILE THE AXIS OF A SHORT-WAVE TROUGH MOVES ALONG
ALABAMA TO N OF 28N IN THE GULF. DIVERGENT FLOW FROM THESE TWO
UPPER LEVEL FEATURES IS ENHANCING ISOLATED RAINSHOWERS AND TSTMS
WITHIN 80 NM OF THE MISSISSIPPI AND ALABAMA COASTS. SE WIND FLOW
IN THE RANGE OF 5-15 KT CONTINUES TO SPREAD OVER MOST OF THE
GULF THIS MORNING. OTHERWISE...DRY AIR BEING ADVECTED FROM THE
CARIBBEAN AS WELL AS DRY AIR IN THE MIDDLE LEVELS IS KEEPING THE
REMAINDER GULF FREE OF CONVECTION.

SURFACE RIDGING AND RETURN FLOW WILL PREVAIL ACROSS THE GULF
DURING THE NEXT 48 HOURS. EXCEPT FOR THE NE GULF WHERE SOME
SHOWERS MAY BE POSSIBLE...FAIR WEATHER IS EXPECTED FOR THE MOST
PART DURING THIS TIME BEING SUPPORTED BY CONTINUOUS DRY AIR
ADVECTION FROM THE CARIBBEAN.

CARIBBEAN SEA...
EXCEPT FOR THE EASTERN CARIBBEAN E OF 67W AND THE SOUTHERN
CARIBBEAN S OF 14N...DRY AIR SPREADS ACROSS THE BASIN IN THE
MIDDLE AND LOWER LEVELS AS DEPICTED IN TOTAL PRECIPITABLE WATER
AND WATER VAPOR IMAGERY WHICH IS SUPPORTING FAIR WEATHER.
NUMEROUS MODERATE CONVECTION IS OVER NICARAGUA AND EXTENDING OFF
ITS COAST WITHIN 200 NM FROM 11N-15N. SCATTERED RAINSHOWERS ARE
OVER COSTA RICA EXTENDING OFF ITS COASTLINE WITHIN 20 NM AND
ISOLATED SHOWERS ARE S OF 11N IN THE REMAINDER SOUTHERN
CARIBBEAN. THE CONVECTION IN THIS REGION IS ASSOCIATED WITH THE
MONSOON TROUGH WHICH AXIS MOVES ACROSS COSTA RICA AND PANAMA TO
NORTHERN COLOMBIA AND WITH BANKING OF HIGH LOW LEVEL MOISTURE BY
STRONG EASTERLY TRADEWINDS. A TIGHT PRESSURE GRADIENT ACROSS
MOST OF THE BASIN IS SUPPORTING TRADEWINDS OF UP TO 25
KT...LIGHTER TRADEWINDS UP TO 15 KT ARE OVER THE WESTERN
CARIBBEAN.

A TROPICAL WAVE IS MOVING ACROSS THE LESSER ANTILLES THIS
MORNING AND WILL CONTINUE A W-NW TRACK TO PASS OVER PUERTO RICO
LATE THIS MORNING...RAINSHOWERS ARE EXPECTED. THE WAVE WILL MOVE
OFF THE WEST COAST LATE TONIGHT AND ENTER THE DOMINICAN REPUBLIC
VERY EARLY ON TUESDAY.

HISPANIOLA...
DRY AIR IN THE LOWER AND MIDDLE LEVELS CONTINUE ACROSS LA
HISPANIOLA THIS MORNING WHICH IS LIMITING ANY CONVECTIVE
ACTIVITY. HOWEVER EARLY THIS AFTERNOON WEATHER CONDITIONS WILL
START TO DETERIORATE AS A TROPICAL WAVE MOVES W-NW ACROSS PUERTO
RICO. THE TROPICAL WAVE IS EXPECTED TO ENTER THE DOMINICAN
REPUBLIC VERY EARLY ON TUESDAY. RAINSHOWERS ARE EXPECTED ACROSS
THE ENTIRE ISLAND AS THE WAVE CONTINUES A W-NW TRACK TO EXIT THE
COAST OF HAITI TUESDAY AFTERNOON.

ATLANTIC OCEAN...
PATCHES OF MODERATE LOW LEVEL MOISTURE AND UPPER LEVEL DIVERGENT
FLOW IS SUPPORTING SCATTERED MODERATE CONVECTION WITH ISOLATED
THUNDERSTORMS N OF 29N BETWEEN 52W-60W. A SURFACE TROUGH EXTENDS
FROM 30N31W SW TO 27N35W AND NO CONVECTION IS ASSOCIATED WITH
IT. OTHERWISE...SURFACE RIDGING IS ACROSS THE REMAINDER BASIN
ANCHORED BY A PAIR OF 1022 MB HIGHS JUST N OF THE AREA OF
DISCUSSION. BESIDES FOR THE AREAS FORMERLY DISCUSSED...FAIR
WEATHER IS ACROSS THE REMAINDER ATLC SUPPORTED BY DRY AIR AT THE
LOWER AND MIDDLE LEVELS.

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

$$
RAMOS


This weather bulletin was brought to you by:
www.nashvilleweather.net