[Tropical] Tropical Weather Discussion

Tue Jul 21 00:47:58 CDT 2015

AXNT20 KNHC 210547
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE JUL 21 2015

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.

...TROPICAL WAVES...

TROPICAL WAVE OFF THE COAST OF AFRICA EXTENDS ALONG 19W FROM 6N-
15N MOVING W NEAR 10 KT OVER THE PAST 12 HOURS. WAVE COINCIDES
WITH A BROAD 700 MB TROUGH THAT COVERS THE AREA BETWEEN AFRICA
AND THE CAPE VERDE ISLANDS AS DEPICTED BY THE GLOBAL MODEL. THE
TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED
WITHIN A LOW AMPLITUDE SURGE OF MODERATE MOISTURE. THE
NOAA/NESDIS AEROSOL PRODUCT AND THE LAST VISIBLE SATELLITE
IMAGERY INDICATES THAT THE WAVE IS EMBEDDED WITHIN A PLUMB OF
AEROSOLS OR SAHARAN DUST LIMITING ANY ASSOCIATED CONVECTION.

TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS ALONG 50W/51W FROM
6N-16N MOVING W 20-25 KT OVER THE PAST 24 HOURS. WAVE IS
EMBEDDED WITHIN A 700 MB TROUGH AS DEPICTED BY THE GLOBAL MODEL.
THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED
WITHIN AN SURGE OF MODERATE TO DEEP MOISTURE. HOWEVER THE
NOAA/NESDIS AEROSOL PRODUCT AND THE LAST VISIBLE SATELLITE
IMAGERY INDICATES THAT THE WAVE IS ALSO EMBEDDED WITHIN A PLUMB
OF AEROSOLS OR SAHARAN DUST LIMITING ANY ASSOCIATED CONVECTION.

TROPICAL WAVE IN THE E CARIBBEAN EXTENDS ALONG 63W S OF 20N TO
INLAND OVER VENEZUELA MOVING W NEAR 20 KT OVER THE PAST 24
HOURS. WAVE COINCIDES WITH A LOW AMPLITUDE 700 MB TROUGH S OF
16N AS DEPICTED BY THE GLOBAL MODEL. THE TOTAL PRECIPITABLE
WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN AN SURGE OF DEEP
MOISTURE THAT EXTENDS NE OF THE WAVE. THE NOAA/NESDIS AEROSOL
PRODUCT AND THE LAST VISIBLE SATELLITE IMAGERY INDICATES THAT
THE WAVE IS ALONG THE LEADING EDGE OF A PLUMB OF AEROSOLS OR
SAHARAN DUST. HOWEVER S OF THE AEROSOLS OR SAHARAN DUST IS
SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 11N-14N
BETWEEN 61W-64W.

TROPICAL WAVE IN THE CENTRAL CARIBBEAN EXTENDS ALONG 70W S OF
17N TO INLAND OVER VENEZUELA MOVING W-SW 20-25 KT OVER THE PAST
24 HOURS. WAVE IS TRAILING THE 700 MB TROUGH THAT COVERS THE
CENTRAL CARIBBEAN AS DEPICTED BY THE GLOBAL MODEL. THE TOTAL
PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A
LOW AMPLITUDE SURFACE OF MODERATE TO DEEP MOISTURE. THE
NOAA/NESDIS AEROSOL PRODUCT AND THE LAST VISIBLE SATELLITE
IMAGERY INDICATES THAT THE WAVE IS ALSO EMBEDDED WITHIN A
PREVIOUS PLUMB OF AEROSOLS OR SAHARAN DUST AGAIN LIMITING ANY
ASSOCIATED CONVECTION.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS BEGINS W OF THE EASTERN MOST TROPICAL
WAVE NEAR 9N21W AND EXTENDS TO 7N31W WHERE THE ITCZ BEGINS AND
CONTINUES ALONG 6N41W TO 8N49W. SCATTERED MODERATE CONVECTION IS
WITHIN 75 NM OF LINE FROM 10N15W TO 6N24W. CLUSTERS OF SCATTERED
MODERATE/ISOLATED STRONG CONVECTION WITHIN 120 NM N OF MONSOON
TROUGH BETWEEN 24W-30W...WITHIN 60 NM EITHER SIDE OF THE ITCZ
BETWEEN 30W-35W...AND WITHIN 90 NM N OF THE ITCZ BETWEEN 39W-
43W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER RIDGE REMAINS OVER E TEXAS COVERING THE NW GULF
WHILE A SECOND UPPER RIDGE HAS DEVELOPED TO THE E OVER E GEORGIA
COVERING THE NE GULF. THE UPPER LOW CENTERED OVER THE NE YUCATAN
PENINSULA COVERS THE S GULF. THE DIURNAL SURFACE TROUGH IS ALONG
THE W COAST OF THE YUCATAN GENERATING SCATTERED SHOWERS AND
POSSIBLE ISOLATED THUNDERSTORMS S OF 20N BETWEEN 91W-93W. A
SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS THE STRAITS OF
FLORIDA THROUGH A 1017 MB HIGH NEAR HAVANA CUBA TO 23N90W.
ISOLATED SHOWERS ARE POSSIBLE ACROSS THE N GULF N OF 27N LEAVING
THE REMAINDER OF THE GULF WITH FAIR WEATHER TONIGHT. SURFACE
RIDGE WILL CHANGE LITTLE THROUGH THU. TROUGH WILL DEVELOP OVER
THE NE GULF WED NIGHT THEN DRIFT E-SE THU.

CARIBBEAN SEA...
AN UPPER LOW IS CENTERED OVER NE YUCATAN PENINSULA NEAR CANCUN
COVERING THE NW CARIBBEAN AND INTO THE GULF OF MEXICO. AN UPPER
RIDGE ANCHORED IN THE TROPICAL ATLC EXTENDS AN UPPER RIDGE AXIS
ACROSS THE WINDWARD ISLANDS NEAR GRENADA ALONG 14N72W TO 14N84W.
AN UPPER TROUGH OVER THE W/CENTRAL ATLC EXTENDS S OVER THE
ISLANDS BETWEEN THE VIRGIN ISLANDS AND HISPANIOLA. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE SW CARIBBEAN WITHIN
90 NM ALONG THE COAST OF PANAMA. ISOLATED SHOWERS/THUNDERSTORMS
ARE ACROSS THE FAR E CARIBBEAN E OF 66W ASSOCIATED WITH THE
TROPICAL WAVE. ISOLATED SHOWERS PERSIST OVER CENTRAL HISPANIOLA.
THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH MOSTLY CLEAR
SKIES TONIGHT. W ATLC SURFACE RIDGE WILL MAINTAIN FRESH TO
OCCASIONALLY STRONG TRADE WINDS ACROSS THE S/CENTRAL CARIBBEAN
THROUGH THU. CENTRAL CARIBBEAN TROPICAL WAVE WILL MOVE INTO THE
W CARIBBEAN TUE NIGHT THROUGH THU. THE E CARIBBEAN TROPICAL WAVE
WILL MOVE INTO THE CENTRAL CARIBBEAN WED AND WED NIGHT. THE
THIRD TROPICAL WAVE WILL MOVE INTO THE E CARIBBEAN WED
AFTERNOON.

...HISPANIOLA...
CURRENTLY...ISOLATED SHOWERS ARE ACROSS THE CENTRAL PORTION OF
THE ISLAND. AN UPPER TROUGH OVER THE W/CENTRAL ATLC COVERS THE
ISLANDS FROM THE VIRGIN ISLANDS TO HISPANIOLA AND WILL PERSIST
THROUGH MID WEEK. MOISTURE WILL INCREASE LATE TUE EVENING AHEAD
OF A TROPICAL WAVE THAT MOVE ACROSS THE ISLAND TUE NIGHT WITH A
SECOND TROPICAL WAVE MOVING ACROSS THE ISLAND LATER IN THE WEEK.
THIS WILL INCREASE THE CHANCE OF SHOWERS AND POSSIBLE
THUNDERSTORMS STARTING TUE AFTERNOON.

ATLANTIC OCEAN...
AN UPPER RIDGE COVERS THE W ATLC N OF 27N W OF 70W. AN UPPER
TROUGH EXTENDS FROM A N UPPER LOW IN THE N/CENTRAL ATLC NEAR
32N43W ALONG 26N56W TO A SECOND WEAKER UPPER LOW NEAR 23N64W
THEN CONTINUING TO 23N71W. AN UPPER RIDGE IS TO THE S ANCHORED
NEAR 13N50W COVERING THE TROPICAL ATLC. BETWEEN THESE UPPER
FEATURES IS A MID LEVEL LOW CENTERED NEAR 25N47W GENERATING
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 23N-
29N BETWEEN 44W-52W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
ARE FROM 15N-23N BETWEEN 60W-65W INCLUDING THE LEEWARD AND
VIRGIN ISLANDS ASSOCIATED WITH THE TROPICAL WAVE IN THE E
CARIBBEAN. THE ATLC BASIN IS DOMINATED BY A SURFACE RIDGE
ANCHORED BY A 1024 MB HIGH NEAR 28N46W WITH A RIDGE AXIS
EXTENDING THROUGH 27N63W INTO THE GULF OF MEXICO THROUGH THE
STRAITS OF FLORIDA. SURFACE RIDGE WILL CHANGE LITTLE THROUGH
THU. THE N PORTION OF THE TROPICAL WAVE ALONG 53W/54W WILL MOVE
ACROSS THE SW ATLC THROUGH THU.

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

$$
PAW
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