000
AXNT20 KNHC 160541
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU MAY 16 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 8N42W TO 2N43W MOVING W AT 15 KT. THE
WAVE REMAINS LOW-AMPLITUDE AND EMBEDDED WITHIN THE ITCZ AXIS.
TOTAL PRECIPITABLE WATER IMAGERY INDICATES THE WAVE LIES WITHIN
A LARGE AREA OF MAXIMUM MOISTURE. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS FROM 7N-10N BETWEEN 39W-45W...AND FROM 2N-
5N BETWEEN 44W-47W. THE WAVE IS EXPECTED TO CONTINUE MOVING
WESTWARD. MOISTURE ASSOCIATED WITH THIS FEATURE SHOULD REACH THE
WINDWARD ISLANDS DURING THE UPCOMING WEEKEND.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA BISSAU NEAR
12N16W TO 8N20W. THE ITCZ BEGINS AT 8N20W AND CONTINUES ALONG
5N30W 6N42W 3N51W. SCATTERED MODERATE/STRONG CONVECTION IS FROM
4N-7N BETWEEN 11W-15W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 2N-6N BETWEEN 24W-28W...FROM 4N-7N BETWEEN
32W-39W...AND FROM EQ-5N BETWEEN 47W-53W.

...DISCUSSION...

GULF OF MEXICO...
SURFACE RIDGING DOMINATES THE GULF OF MEXICO AROUND A 1021 MB
HIGH SOUTH OF THE FLORIDA PANHANDLE NEAR 29N84W. AN UPPER LEVEL
RIDGE ALONG 85W SUPPORTS THE SURFACE RIDGE. CLEAR SKIES ARE
NOTED OVER THE MAJORITY OF THE BASIN EXCEPT FOR SOME MODERATE
MOISTURE OVER THE WESTERN GULF ALONG THE MEXICO AND TEXAS
COASTS. A FEW ISOLATED SHOWERS MAY ALSO BE OVER ALABAMA AND THE
WESTERN FLORIDA PANHANDLE CONNECTED TO AN UPPER LEVEL LOW OVER
OKLAHOMA. LIGHT ANTI-CYCLONIC WINDS ARE IN THE NE GULF AROUND
THE HIGH CENTER INCREASING TO 15 KT ON THE OUTER PERIMETER OF
THE BASIN INCLUDING MUCH OF THE WESTERN HALF WEST OF 90W.
SURFACE RIDGING WILL CONTINUE TO DOMINATE THE BASIN FOR AT LEAST
THE NEXT SEVERAL DAYS.

CARIBBEAN SEA...
MOSTLY FAIR CONDITIONS SPREAD ACROSS THE CARIBBEAN DUE TO DRY
AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING THE WESTERN
CARIBBEAN ALONG 85W. ONLY A FEW WIDELY ISOLATED SHOWERS ARE
POSSIBLE ACROSS CUBA AND TO THE SOUTH ASSOCIATED WITH A
DISSIPATING COLD FRONT IN THE ATLC THAT EXTENDS TO EASTERN CUBA.
AN UPPER LEVEL TROUGH IS DIGGING SOUTH INTO THE EASTERN
CARIBBEAN. WHILE MOSTLY DRY AIR STILL REMAINS ACROSS THE AREA
PROVIDING FAIR CLEAR SKIES ACROSS MUCH OF THE AREA...A THIN
SWATH OF MOISTURE EXTENDS FROM NEAR HISPANIOLA EASTWARD ACROSS
THE NE CARIBBEAN ISLANDS. SCATTERED SHOWERS ARE IN THIS AREA
FROM 16N-19N BETWEEN 65W-74W. TRADEWIND FLOW OF 15-20 KT
DOMINATES THE MAJORITY OF THE EASTERN AND CENTRAL CARIBBEAN WITH
A FEW 25 KT WINDS NEAR THE COAST OF COLOMBIA. MODEL GUIDANCE
INDICATES THAT THE UPPER TROUGH OVER THE EASTERN CARIBBEAN
SHOULD SHIFT EAST OVER THE NEXT COUPLE OF DAYS. HOWEVER...THE
MOISTURE IN THIS AREA APPEARS TO DRIFT WEST AND WILL LIKELY
CONTINUE TO PRODUCE SHOWERS AND THUNDERSTORMS ACROSS THE
NORTHERN CARIBBEAN.

HISPANIOLA...
A THIN SWATH OF MOISTURE LIES ACROSS HISPANIOLA AROUND AN UPPER
LEVEL TROUGH ACROSS THE EASTERN CARIBBEAN. CURRENTLY SCATTERED
SHOWERS WITH ISOLATED THUNDERSTORMS APPEAR TO BE CONCENTRATED
OVER THE SW PORTION OF THE ISLAND WITH ACTIVITY ALSO SOUTH OF
THE ENTIRE ISLAND. MODEL GUIDANCE INDICATES THAT ENHANCED
MOISTURE WILL REMAIN OVER THE ISLAND FOR AT LEAST THE NEXT 24-48
HOURS...WHICH MEANS SHOWERS WILL BE LIKELY...ESPECIALLY DURING
THE AFTERNOON HOURS. LOCALIZED FLOODING IS POSSIBLE NEAR AREAS
OF HEAVY RAIN.

ATLANTIC OCEAN...
SURFACE HIGH PRESSURE CONTINUES TO BUILD ACROSS THE WESTERN ATLC
AROUND A 1023 MB HIGH NEAR 32N71W. AN UPPER LEVEL TROUGH TO THE
EAST ALONG 31N57W TO 19N65W SUPPORTS A COLD FRONT THAT ENTERS
THE DISCUSSION AREA NEAR 32N56W AND CONTINUES TO 23N67W WHERE IT
DISSIPATES TO EASTERN CUBA AT 21N77W. ISOLATED SHOWERS ARE
WITHIN 100 NM OF THE AXIS WITH A CLUSTER OF SCATTERED ACTIVITY
AND ISOLATED THUNDERSTORMS NEAR 25N60W. AN UPPER LEVEL RIDGE IS
ALONG 45W SUPPORTING A BROAD SURFACE RIDGE ACROSS THE REMAINDER
OF THE CENTRAL AND EASTERN ATLC ANCHORED BY A 1037 MB HIGH NEAR
46N37W. HOWEVER...A WEAK 1018 MB SURFACE LOW NEAR 29N41W
DISTURBS THE RIDGE ALONG WITH A SURFACE TROUGH THAT EXTENDS
THROUGH THE LOW CENTER ALONG 31N41W 26N42W. POSSIBLE ISOLATED
SHOWERS ARE NORTH OF 25N BETWEEN 33W-37W...AND NORTH OF 28N
BETWEEN 37W-45W. BROAD UPPER LEVEL RIDGING DOMINATES THE
REMAINDER OF THE TROPICAL ATLC.

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

$$
WALTON