[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 141804
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT THU APR 14 2016

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA TO OVER THE E
TROPICAL ATLC NEAR 07N12W TO 02N21W WHERE IT TRANSITIONS TO THE
ITCZ AXIS TO 02N30W TO 03N39W WHERE IT IS BISECTED BY A TROUGH
ALONG 39W FROM 01N TO 09N. IT RESUMES AT 03N40W THEN GRADUALLY
BECOMES ILL-DEFINED TO THE EQUATOR NEAR 48W. CLUSTERS OF
SCATTERED STRONG CONVECTION ARE WITHIN 60 NM OF THE AXIS BETWEEN
18W-20W...AND WITHIN 60 NM N OF THE AXIS BETWEEN 23W-25W.
WEAKENING SCATTERED MODERATE CONVECTION IS WITHIN 60 NM N OF THE
AXIS BETWEEN 28W-29W...AND WITHIN 60 NM S OF AXIS BETWEEN 42W-
43W.

...DISCUSSION...

GULF OF MEXICO...

BROAD UPPER RIDGING COVERS THE JUST ABOUT THE AREA S OF 28N. IT
IS ANCHORED BY A AN ANTICYCLONE CENTERED IN THE FAR EASTERN
PACIFIC. TO THE N OF 28N...THE SOUTHERN PORTION OF BROAD MID TO
UPPER TROUGHING IS PRESENT OVER THAT PORTION OF THE GULF. A
RATHER PRONOUNCED JET STREAM BRANCH STRETCHES FROM THE EASTERN
PACIFIC ENE...AND RIDES THE NORTHERN CREST OF THE RIDGE ESE TO
OVER CENTRAL FLORIDA. THE ASSOCIATED UPPER FLOW IS ADVECTING
UPPER LEVEL MOISTURE IN THE FORM OF BROKEN HIGH CLOUDS EASTWARD
S OF 26N. AT THE SURFACE...A PERSISTENT STATIONARY FRONTAL
BOUNDARY IS ANALYZED FROM CENTRAL FLORIDA WSW TO NEAR THE TAMPA
AREA...THEN NW TO 29N88W AND SW TO 29N92W TO A WEAK 1012 MB LOW
AT 27N95W. A TROUGH EXTENDS FROM THE LOW SSW TO 24N95W AND TO
NEAR VERACRUZ. LATEST SATELLITE IMAGERY AND NWS MOSAIC RADAR
IMAGERY SHOW INCREASING CLUSTERS OF SCATTERED SHOWERS AND TSTMS
OF MODERATE INTENSITY CONVECTION MOVING QUICKLY EASTWARD ALONG
AND WITHIN 60 NM S OF THE FRONTAL BOUNDARY BETWEEN 87W-90W. THIS
ACTIVITY IS LIKELY TO CONTINUE TO INCREASE THROUGH THE REST OF
THE AFTERNOON AND TONIGHT AS RIPPLES OF ENERGY IN THE JET STREAM
FLOW ALOFT IN COMBINATION WITH THE SURFACE FRONTAL BOUNDARY COME
TOGETHER TO FURTHER SUPPORT THIS ACTIVITY AS WELL AS TRIGGER OFF
ADDITIONAL SHOWERS AND TSTMS. ISOLATED SHOWERS AND TSTMS ARE
ELSEWHERE S OF THE FRONTAL BOUNDARY W OF ABOUT 84W MOVING TO THE
N IN A VERY MOIST SE-S FLOW. THE STATIONARY FRONT WILL LINGER
THROUGH FRI NIGHT...GRADUALLY DISSIPATING SAT AS HIGH PRES
BUILDS DOWN FROM THE NE. THE PRES GRADIENT WILL TIGHTEN AS THE
HIGH BUILDS IN WITH INCREASED TROUGHING IN THE SOUTHERN PLAINS.
A TROUGH WILL DEVELOP OVER THE YUCATAN PENINSULA EACH AFTERNOON
AND WEAKEN AS IT MOVES W OVERNIGHT EACH NIGHT.

CARIBBEAN SEA...

THE UPPER RIDGE OVER THE GULF CONTINUES TO DOMINATE THE
CARIBBEAN W OF ABOUT 75W. AN UPPER TROUGH OVER THE CENTRAL ATLC
DIPS S OVER THE NE CARIBBEAN TO THE LEEWARD ISLANDS. MODERATE TO
STRONG SUBSIDENCE AND DRY STABLE AIR CONTINUES TO DOMINATE ALL
OF THE CARIBBEAN EXCEPT THE EXTREME NW. ISOLATED SHOWERS AND
TSTMS MAY BE FORMING OVER THE SOME PORTIONS OF THE INTERIOR OF
HISPANIOLA AS DAYTIME HEATING GETS UNDERWAY. WEAK ISOLATED
SHOWERS AND TSTMS ARE WITHIN 90 NM S OF HISPANIOLA IN THE WAKE
OF AN ARC CLOUD AS DESCRIBED ABOVE. LOW-LEVEL MOISTURE NEAR THE
SOUTHERN PART OF THE ATLC SURFACE TROUGH IS CONTINUING TO
PRODUCE SCATTERED SHOWERS OVER THE LESSER ANTILLES BETWEEN SAINT
LUCIA AND DOMINICA. THE REMAINDER OF THE CARIBBEAN IS UNDER
GENERALLY PARTLY CLOUDS SKIES TO MOSTLY CLEAR SKIES UNDER THE
INFLUENCE OF THE DRY AIR ALOFT. WINDS AND SEAS WILL REMAIN BELOW
NORMAL THROUGH FRI AS THE LOW/SURFACE TROUGH DOMINATES THE AREA
N OF THE LEEWARD ISLANDS. IN ADDITION...THE PRESSURE GRADIENT IS
FORECAST TO RELAX SOME ACROSS THE WESTERN AND CENTRAL CARIBBEAN
LATE ON SAT. FRESH TRADE WINDS WILL RETURN ALONG THE COAST OF
COLOMBIA LATE THU THROUGH SUN AND WILL INCREASE TO STRONG BREEZE
EACH NIGHT. A FRESH E TO SE BREEZE WILL DEVELOP ACROSS THE GULF
OF HONDURAS THU AND FRI...AND WILL BECOME FRESH TO LOCALLY
STRONG OVER THE WEEKEND.

HISPANIOLA...

VISIBLE SATELLITE IMAGERY SHOWS BUILDING LOW CLOUDS OVER
THE INTERIOR OF HISPANIOLA WITH POSSIBLE ISOLATED SHOWERS AND
WEAK ISOLATED TSTMS. A LARGE ARC CLOUD THAT PUSHED OFF THE
ISLAND LAST NIGHT IS VISIBLE FROM 18N73W TO 16N73W TO ALONG A
POSITION. IT IS RACING WESTWARD WITH WEAKENING ISOLATED SHOWERS
AND TSTMS ALONG AND WITHIN 180 NM TO ITS E. THE 1354 UTC ASCAT
PASS INDICATED NE-E WINDS OF 15-20 KT BETWEEN THE ARC AND 69W.
LOW-LEVEL MOISTURE IS EXPECTED TO REMAIN JUST S OF THE ISLAND
WHICH COULD LEAD TO THE DEVELOPMENT OF ISOLATED SHOWERS AND
THUNDERSTORMS ALONG AND NEAR THE S COAST THROUGH FRI NIGHT WHEN
THE MOISTURE IS FORECAST TO AGAIN MOVE OVER THE ISLAND. THIS
SHOULD PROVIDE THE ISLAND WITH A CHANCE OF SHOWERS AND POSSIBLE
ISOLATED TSTMS THROUGH THE NEXT COUPLE OF DAYS.

ATLANTIC OCEAN...

AN UPPER TROUGH OVER THE WESTERN ATLC SUPPORTS A COLD FRONT N OF
32N...AND A STATIONARY FRONT THAT EXTENDS FROM 32N75W SW TO
A WEAK 1016 MB LOW AT 29N80W...AND CONTINUES SW FROM THE LOW
TO INLAND THE CAPE CANAVERAL AREA. LATEST SATELLITE IMAGERY IS
REVEALING SCATTERED SHOWERS AND ISOLATED TSTMS N OF 29N E OF THE
LOW/FRONT TO NEAT 72W. A MID/UPPER LEVEL TROUGH OVER THE CENTRAL
ATLC EXTENDS INTO THE NE CARIBBEAN SEA. IT IS SUPPORTING A
SURFACE TROUGH THAT EXTENDS FROM A 1011 MB LOW NEAR 24N61W TO
THE LEEWARD ISLANDS NEAR DOMINICA. DIFFLUENT FLOW ALOFT IN
COMBINATION WITH THE LIFT FROM THE TROUGH DYNAMICS IS SETTING
OFF INCREASING CLUSTERS OF SCATTERED MODERATE CONVECTION FROM
23N-30N BETWEEN 50W-57W. SCATTERED SHOWERS AND ISOLATED TSTMS
ARE NOTED FROM 26N-30N BETWEEN 57W-62W. A LARGE UPPER LOW OVER
THE NE ATLC IS SUPPORTING A COLD FRONT THAT EXTENDS INTO THE
EASTERN ATLC THROUGH 32N22W TO 27N34W AND NW TO 28N42W WHERE IT
BECOMES STATIONARY TO BEYOND 32N57W. A WEAK SURFACE RIDGE IS S
OF THIS FRONT OVER THE REMAINDER OF THE ATLC E OF THE
LOW/SURFACE TROUGH WITH A 1018 MB HIGH CENTER AT 22N32W. THE
LOW/SURFACE TROUGH WILL SLOWLY SHIFT E-NE ACROSS THE CENTRAL
ATLC THROUGH THE NEXT 48 HOURS. WITH THE MID AND UPPER FLOW
PATTERN FORECAST TO BECOME MORE NORTHWESTERLY THROUGH THE NEXT
48 HOURS...THIS WILL ENABLER THE WESTERN ATLC STATIONARY FRONT
TO TRANSITION TO A COLD FRONT LATE TONIGHT INTO EARLY FRI FROM
NEAR 32N73W TO 29.5N77W TO 30N79W...FROM 32N60W ALONG 27N65W TO
26N71W TO MELBOURNE FLORIDA FRI NIGHT...AND FROM 32N64W TO
30N70W TO 29N77W TO 30N81W BY EARLY SAT BEFORE SHIFTING ESE OF
THE AREA SAT NIGHT AND SUN.

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

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AGUIRRE
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