[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 242340
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN JUL 24 2011

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2300 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ACROSS THE CENTRAL TRPCL ATLC ALONG 16N36W TO
10N42W MOVING W NEAR 12 KT. SATELLITE IMAGERY INDICATES BROAD
LOW-LEVEL CYCLONIC FLOW IS AROUND THE WAVE AXIS...WHICH IS ALSO
INDICATED BY AN ASCAT SCATTEROMETER PASS FROM EARLIER TODAY.
TOTAL PRECIPITABLE WATER IMAGERY SHOWS THAT THE WAVE LIES ON THE
WRN SIDE OF A SURGE OF DEEP LAYER MOISTURE. ISOLATED MODERATE
CONVECTION IS FROM 13N-15N BETWEEN 36W-40W.

TROPICAL WAVE CONTINUES TO PUSH ACROSS THE N CENTRAL CARIBBEAN
CURRENTLY OVER HAITI FROM 24N72W TO 16N72W MOVING WNW NEAR 20
KT. VERY BROAD SURFACE CYCLONIC FLOW CAN BE SEEN IN VISIBLE
SATELLITE IMAGERY WITH MORE EVIDENT CYCLONIC FLOW IN THE LOW-MID
LEVEL CLOUDS. TOTAL PRECIPITABLE WATER IMAGERY INDICATES HIGH
MOISTURE VALUES SURROUND THE WAVE FROM 15N-25N BETWEEN 65W-77W.
NUMEROUS STRONG CONVECTION IS FROM 19N-21N BETWEEN 69W-71W...AND
FROM 20N-21N BETWEEN 72W-74W WITH MODERATE CONVECTION COVERING
THE REMAINDER OF THE AREA FROM 18N-21N BETWEEN 66W-76W.
SCATTERED MODERATE CONVECTION IS FROM 18N-21N BETWEEN 76W-80W.
MUCH OF THIS ACTIVITY IS ACROSS HISPANIOLA WHICH HAS ALREADY
RECEIVED HIGH RAINFALL AMOUNTS. WITH SATURATED GROUNDS IN HIGH
TERRAIN...FLOODING AND MUDSLIDES ARE POSSIBLE AS THE WAVE
CONTINUES TO MOVE WNW. AS THE WAVE AND MOISTURE CONTINUE TOWARDS
CUBA...SHOWER ACTIVITY WILL INCREASE ACROSS THE ISLAND.

...ITCZ/MONSOON TROUGH...

MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT
18N ALONG 20N9W TO THE COAST OF GUINEA-BISSAU AT 12N16W TO
6N27W. THE ITCZ CONTINUES FROM 6N27W ALONG 10N37W 11N51W 9N64W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 100 NM S
OF THE AXIS BETWEEN 15W-23W. SIMILAR ACTIVITY IS FROM 5N-8N
BETWEEN 24W-28W.

...DISCUSSION...

GULF OF MEXICO...
SURFACE RIDGING CONTINUES TO COVER THE GULF OF MEXICO THIS
EVENING AROUND A PAIR OF 1020 MB HIGHS NEAR 22N99W AND 28N92W
PROVIDING MOSTLY FAIR WEATHER ACROSS THE BASIN. THE RIDGE IS
SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED OVER TENNESSEE WHICH
IS PROVIDING MAINLY NE-E FLOW ALOFT ACROSS THE BASIN. TOTAL
PRECIPITABLE WATER IMAGERY CONTINUES TO SHOW MODERATE MOISTURE
VALUES ACROSS THE N CENTRAL GULF WHICH COINCIDES WITH AN AREA OF
ISOLATED SHOWERS/THUNDERSTORMS N OF 26N BETWEEN 87W-94W.
CLUSTERS OF STRONG STORMS ARE ALSO ACROSS NE AND SW FLORIDA.
NUMEROUS SHOWERS/THUNDERSTORMS ARE ALSO NOTED ACROSS THE NRN
YUCATAN PENINSULA FROM 19N-22N BETWEEN 88W-91W. THIS AREA OF
ACTIVITY IS BEGINNING TO MOVE WWD INTO THE BAY OF CAMPECHE. THIS
ACTIVITY MAY BE ASSOCIATED WITH AN UPPER LEVEL LOW CENTERED OVER
THE NE YUCATAN. EXPECT SURFACE RIDGING TO REMAIN ACROSS THE
BASIN WITH SHOWERS/THUNDERSTORMS LIKELY OVER THE NRN GULF AS
HIGHER MOISTURE VALUES REMAIN. SHOWER ACTIVITY WILL BEGIN TO
INCREASE OVER THE SE GULF IN THE NEXT COUPLE OF DAYS AS MOISTURE
PRECEDING A TROPICAL WAVE IN THE CARIBBEAN MOVES TOWARDS THE
AREA.

CARIBBEAN SEA...
AN UPPER LEVEL LOW PREVIOUSLY OVER THE NW CARIBBEAN HAS NOW
SHIFTED OVER THE NE YUCATAN PENINSULA PLACING THE AREA OF
DIFFLUENCE OVER THE NW CARIBBEAN SUPPORTING AN AREA OF
SHOWERS/THUNDERSTORMS FROM 18N-20N BETWEEN 81W-85W. SCATTERED
SHOWERS/THUNDERSTORMS ARE ALSO OVER NRN
NICARAGUA...HONDURAS...AND CUBA. SHOWERS/THUNDERSTORMS ACROSS
ERN CUBA AND THE WATERS TO THE S TO JAMAICA ARE ASSOCIATED WITH
MOISTURE AHEAD OF A TROPICAL WAVE CURRENTLY OVER HAITI. STRONG
SHOWERS/THUNDERSTORMS ARE ACROSS MUCH OF HISPANIOLA IN
CONNECTION WITH THE WAVE. SEE TROPICAL STORM SECTION ABOVE FOR
MORE DETAILS. HISPANIOLA AS WELL AS CUBA SHOULD BE PREPARED FOR
CONTINUED SHOWER ACTIVITY AS THE WAVE MOVES WNW. AREAS THAT HAVE
ALREADY RECEIVED HIGH AMOUNTS OF RAINFALL OR IN HIGH TERRAIN ARE
IN RISK OF FLASH FLOODING AND MUDSLIDES. THE ERN CARIBBEAN IS
UNDER MOSTLY FAIR WEATHER WITH NE-E TRADEWINDS OF 20-25 KTS.
ALOFT...AN UPPER LEVEL RIDGE COVERS THE ERN HALF OF THE BASIN
WITH AXIS EXTENDING FROM N OF HISPANIOLA NEAR 23N70W TO THE
WINDWARD ISLANDS NEAR 13N61W. DRY AIR ALOFT AROUND THE SRN
EXTENT OF THE UPPER RIDGE AND ALSO ACROSS THE SW CARIBBEAN IS
LIMITING SHOWER ACTIVITY NEAR THE MONSOON TROUGH WHICH EXTENDS
FROM THE E PACIFIC ACROSS PANAMA TO NRN COLOMBIA.

ATLANTIC OCEAN...
BROAD SURFACE RIDGING CONTINUES TO DOMINATE THE ATLC ANCHORED BY
A 1023 MB HIGH NEAR 30N58W...AND A 1031 MB AZORES HIGH NEAR
40N27W PROVIDING MOSTLY FAIR WEATHER BASIN-WIDE. SCATTERED
SHOWER/THUNDERSTORMS...SOME STRONG...ARE MOVING N FROM
HISPANIOLA TOWARDS TURKS AND CAICOS ASSOCIATED WITH A TROPICAL
WAVE ACROSS HAITI WHICH EXTENDS NWD TO 24N71W. SHOWER ACTIVITY
WILL CONTINUE TO IMPACT THE WATERS AND ISLANDS N OF THE CENTRAL
CARIBBEAN AS THE WAVE MOVES WNW. ALOFT...AN UPPER LEVEL LOW
COVERS THE FAR WRN ATLC CENTERED NEAR 29N75W. AN UPPER LEVEL
RIDGE IS TO THE SE WITH AXIS ALONG 23N70W TO 13N61W. ANOTHER
UPPER LEVEL LOW IS SPINNING IN THE CENTRAL ATLC NEAR 30N46W WITH
AXIS EXTENDING TO NEAR 19N59W. AN UPPER LEVEL RIDGE COVERS THE
CENTRAL TROPICAL ATLC CENTERED NEAR 16N34W. A SECOND UPPER LEVEL
RIDGE COVERS W AFRICA CENTERED NEAR 25N9W.

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

$$
WALTON




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