[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201038
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON JUL 20 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC EXTENDS ALONG 43W/44W
FROM 6N-17N MOVING W 15-20 KT OVER THE PAST 24 HOURS. WAVE IS
TRAILING THE 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 W TROPICAL ATLC EXTENDS ALONG 55W/56W FROM
8N-22N MOVING W 10-15 KT OVER THE PAST 24 HOURS. WAVE COINCIDES
WITH A LOW AMPLITUDE 700 MB TROUGH S OF 14N AS DEPICTED BY THE
GLOBAL MODEL. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE
WAVE IS EMBEDDED WITHIN AN SURGE OF DEEP MOISTURE THAT EXTENDS N
OF 26N. 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 9N-11N BETWEEN 51W-53W AND FROM 10N-13N BETWEEN
53W-56W.

TROPICAL WAVE IN THE E CARIBBEAN EXTENDS ALONG 62W/63W FROM 10N-
19N MOVING W NEAR 10 KT OVER THE PAST 24 HOURS. WAVE IS TRAILING
THE 700 MB TROUGH THAT COVERS THE FAR E CARIBBEAN AND EXTENDS N
INTO THE CENTRAL ATLC AS DEPICTED BY THE GLOBAL MODEL. THE TOTAL
PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN AN
AREA OF MODERATELY DRY AIR. 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 EXTENDS ACROSS AFRICA INTO THE E
TROPICAL ATLC NEAR 14N17W ALONG 8N23W TO 9N33W WHERE THE ITCZ
BEGINS AND CONTINUES TO E OF THE EASTERN MOST TROPICAL WAVE NEAR
11N42W THEN RESUMES W OF THE WAVE NEAR 11N45W TO THE NEXT WAVE
NEAR 9N53W THEN RESUMES NEAR 10N57W TO SOUTH AMERICA NEAR 8N59W.
SCATTERED MODERATE CONVECTION IS FROM 6N-9N BETWEEN 28W-32W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER RIDGE COVERS THE N GULF AND INTO THE W ATLC ANCHORED
OVER E TEXAS WHILE AN INVERTED UPPER TROUGH OVER THE W CARIBBEAN
IS GIVING THE S GULF EASTERLY FLOW ALOFT. A SURFACE TROUGH
EXTENDS FROM NE FLORIDA INTO THE GULF NEAR 29.5N83.5W TO 29N89W
AND IS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS N OF 27N E OF 89W. THE DIURNAL SURFACE TROUGH IS
OVER THE E BAY OF CAMPECHE ALONG 92W S OF 21N GENERATING
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 20N E
OF 94W. THE REMAINDER OF THE GULF IS DOMINATED BY A SURFACE
RIDGE THAT EXTENDS FROM THE W ATLC ACROSS S FLORIDA TO NE MEXICO
WITH A 1018 MB HIGH NEAR 24N86W. THIS IS LEAVING THE REMAINDER
OF THE GULF WITH FAIR WEATHER THIS MORNING. SURFACE RIDGE WILL
SHIFT TO THE E GULF TODAY THEN CHANGE LITTLE THROUGH MID WEEK.

CARIBBEAN SEA...
AN INVERTED UPPER TROUGH EXTENDS FROM GUATEMALA INTO THE GULF OF
HONDURAS TO E CUBA COVERING THE W CARIBBEAN W OF 80W. AN UPPER
RIDGE ANCHORED IN THE TROPICAL ATLC EXTENDS AN UPPER RIDGE AXIS
ACROSS THE LESSER ANTILLES NEAR MARTINIQUE ALONG 14N73W TO
15N80W. THE SOUTHERLY FLOW ALOFT ACROSS THE S CARIBBEAN IS
ADVECTING UPPER MOISTURE OVER THE S CARIBBEAN BRINGING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS S OF LINE FROM COLOMBIA NEAR
10N75W 11N81W TO NICARAGUA NEAR 13N84W. ISOLATED SHOWERS/
THUNDERSTORMS REMAIN OFF THE COAST OF CUBA FROM 18N-21N BETWEEN
78W-80W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS
ARE OVER SW HAITI. THIS IS LEAVING THE REMAINDER OF THE
CARIBBEAN WITH MOSTLY CLEAR SKIES THIS MORNING. ATLC SURFACE
RIDGE WILL MAINTAIN FRESH TO OCCASIONALLY STRONG TRADE WINDS
ACROSS THE S/CENTRAL CARIBBEAN THROUGH MID WEEK. E CARIBBEAN
TROPICAL WAVE WILL MOVE ACROSS THE CENTRAL CARIBBEAN TUE THROUGH
WED NIGHT. THE NEXT TROPICAL WAVE WILL ENTER THE E CARIBBEAN
EARLY TUE AND MOVE THROUGH THE E CARIBBEAN BY WED NIGHT. THE
THIRD TROPICAL WAVE WILL MOVE INTO THE E CARIBBEAN THU.

...HISPANIOLA...
CURRENTLY...SCATTERED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS ARE OVER SW HAITI. AN UPPER TROUGH OVER THE
CENTRAL ATLC DIPS S OVER THE N PORTION OF THE ISLAND. THIS UPPER
TROUGH WILL ENCOMPASS THE ISLAND BY TONIGHT AND WILL PERSIST
THROUGH MID WEEK. MOISTURE WILL INCREASE LATE TONIGHT AHEAD OF A
SERIES OF TROPICAL WAVES THAT MOVE ACROSS THE ISLAND TUE THROUGH
THE END OF 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 23N W OF 70W. AN UPPER LOW
IS IN THE N/CENTRAL ATLC NEAR 30N51W EXTENDING AN UPPER TROUGH
SW ALONG 24N65W TO OVER THE N PORTION OF HISPANIOLA. AN UPPER
RIDGE IS TO THE S ANCHORED NEAR 15N53W COVERING THE TROPICAL
ATLC. BETWEEN THESE UPPER FEATURES...IS AN AREA OF DIFFLUNCE
ALOFT THAT IS GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS FROM 23N-27N BETWEEN 50W-55W. THE ATLC BASIN IS
DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH NEAR
29N45W WITH A RIDGE AXIS EXTENDING THROUGH 26N69W INTO THE GULF
OF MEXICO OVER S FLORIDA. SURFACE RIDGE WILL SHIFT SLIGHTLY S
TUE NIGHT THE CHANGE LITTLE THROUGH MID WEEK. THE N PORTION OF
THE TROPICAL WAVE ALONG 53W/54W WILL MOVE ACROSS THE SW ATLC MON
THROUGH WED.

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

$$
PAW
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