Caribbean - Central America Weather

[Gustywind]

Thanks for posting everyday... el talento de la casa... CYCLONEYE

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
540 AM AST SAT DEC 12 2015

.SYNOPSIS...AT UPPER LEVELS...A TROUGH JUST EAST OF FLORIDA WILL
PINCH OFF A LOW PRESSURE THAT WILL SETTLE IN THE WINDWARD PASSAGE
BY SUNDAY AND NOT MOVE OUT UNTIL WEDNESDAY. IT CROSSES SOUTH OF
PUERTO RICO AND THE U.S. VIRGIN ISLANDS ON THURSDAY AS THE TROUGH
IT IS IN TAKES ON A DISTINCTIVE EAST-WEST ORIENTATION OVER THE
FORECAST AREA THEREAFTER.

AT MID LEVELS...A TROUGH OVER THE BAHAMA ISLANDS WILL FOLLOW THE
UPPER LEVEL PATTERN THROUGH THURSDAY. HIGH PRESSURE WILL DEVELOP
NORTHEAST OF THE AREA OVER THE FOLLOWING WEEKEND. PATCHES OF
MOISTURE DRIFT OUT OF THE EAST OVER THE AREA UNTIL AN OLD FRONTAL
BOUNDARY PUSHES THROUGH FROM THE EAST NORTHEAST AND BRINGS IN A
POCKET OF DRY AIR THURSDAY THROUGH THE FOLLOWING MONDAY. ANOTHER
FRONTAL BOUNDARY...ACCORDING TO THE GFS...APPROACHES THE AREA FROM
THE NORTHWEST EARLY IN THE CHRISTMAS WEEK.

AT LOWER LEVELS...LOW PRESSURE REMAINS IN THE SOUTHWEST CARIBBEAN
THROUGH THE PERIOD. HIGH PRESSURE IN THE WESTERN ATLANTIC EAST OF
SOUTH CAROLINA SLIDES SOUTHEAST AND WEAKENS TODAY THROUGH
THURSDAY. AFTER A SERIES OF LOWS PASS THROUGH THE ATLANTIC MOST
OF NEXT WEEK...HIGH PRESSURE RE-BUILDS IN THE CENTRAL...AND THEN
EAST-CENTRAL ATLANTIC...TO HOLD TRADE WIND FLOW OVER THE AREA.

&&

.DISCUSSION...MINIMAL SHOWER ACTIVITY MOVED THROUGH THE LOCAL
WATERS AND OCCASIONALLY ONSHORE IN PUERTO RICO TO BRING VERY
LIGHT SHOWERS TO THE THE EASTERN SLOPES OF THE ISLAND. MOISTURE IS
SLOWLY INCREASING...BUT MID-LEVEL MOISTURE REMAINS ABSENT SAVE FOR
THE CONTRIBUTION OF LOWER LEVELS DURING DAILY HEATING. ON THE
OTHER HAND...LOWER LEVELS...ALTHOUGH NOT ABUNDANTLY RICH WITH
MOISTURE...ARE RUNNING FROM 60 TO 80 PERCENT RELATIVE HUMIDITY THROUGH
THE NEXT 10 DAYS. AS DYNAMICS ARE LIMITED DUE TO WEAK LOW PRESSURE
AT UPPER LEVELS REMAINING FAIRLY DISTANT UNTIL MID WEEK NEXT
WEEK...WITH LITTLE CONVERGENCE OR FORCING AT ANY LEVEL...ONLY
WEAK SHOWERS ARE EXPECTED EXCEPT IN THE DOWN STREAM CORNER...IN
THIS CASE... THE NORTHWEST CORNER...DURING THE AFTERNOON HOURS AND
THE WINDWARD SLOPES NIGHTS AND EARLY MORNINGS. EAST SOUTHEAST
FLOW IS ALSO BEING VERY PERSISTENT DUE TO THE HIGHER PRESSURE TO
THE NORTHEAST AND IS EXPECTED TO CONTINUE THROUGH ALL OF NEXT
WEEK. HIGHER CLOUDS WILL INCREASE MID WEEK NEXT WEEK WHEN THE
UPPER LEVEL LOW MOVES THROUGH THE AREA. BUT THE GFS STILL WANTS TO
BRING DRIER AIR IN ABOVE THE MARINE LAYER...TOPPING OUT AT AROUND
7000 FEET...AFTER THURSDAY NIGHT AND THIS CAN AT LEAST BRING HOPES
FOR A DRIER WEEKEND NEXT WEEK. IN THE MEANTIME OVERALL CONDITIONS
OF WIDELY SCATTERED SHOWERS WILL PREVAIL WITH NEAR NORMAL OR
SLIGHTLY ABOVE NORMAL TEMPERATURES.

&&

.AVIATION...MAINLY VFR CONDS EXPECTED THRU THE FCST PERIOD ACROSS
ALL TERMINALS. HOWEVER...SHRA/TSRA EXPECTED BTW 12/18Z-22Z ACROSS
THE NW QUADRANT OF PR. THIS COULD LEAD TO BRIEF MVFR CONDS AND MTN
TOP OBSCD...IMPACTING MAINLY THE FLYING AREA OF TJBQ/JMZ. SFC
WINDS FROM THE ESE AT 10 TO 15 KT WITH HIGHER GUSTS IN/NEAR
TSRA/SHRA AND SEA BREEZE VARIATIONS AFTER 12/14Z.

&&

.MARINE...SEAS IN THE ATLANTIC WILL INCREASE NOW THROUGH MONDAY
WITH THE ADDITION OF A NORTHERLY SWELL AND A MODEST INCREASE IN
WIND WAVES DURING THAT PERIOD. SEAS RETURN TO PRESENT LEVELS MID
WEEK NEXT WEEK AS GRADIENTS NEAR AND FAR RELAX SOMEWHAT. SEAS IN
THE CARIBBEAN INCREASE THROUGH SUNDAY WITH LITTLE INPUT FROM
SWELL EXCEPT IN THE PASSAGES.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 86 76 / 20 20 10 30
STT 85 75 85 75 / 20 20 10 20

[cycloneye]

EA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
258 PM AST SAT DEC 12 2015

.SYNOPSIS...MID LEVEL RIDGE WILL HOLD THROUGH THE END OF THE
WEEKEND...KEEPING THE ATMOSPHERE FAIRLY STABLE ACROSS THE LOCAL
REGION. MID/UPPER LEVEL TROUGH LOCATED ACROSS THE NORTHWEST
CARIBBEAN...WILL SLOWLY MOVE EASTWARD INTO THE CENTRAL AND
NORTHEAST CARIBBEAN. AS IT APPROACHES FROM THE WEST...THE UPPER
TROUGH WILL ERODE THE MID-UPPER RIDGE AND WEAKENS THE CAP
INVERSION EARLY NEXT WEEK...FAVORING THE MOISTURE TRANSPORT
ACROSS THE LOCAL ISLANDS FROM SUNDAY THROUGH EARLY NEXT WEEK.

&&

.DISCUSSION...A BRIEF SURGE OF MOISTURE MOVED ACROSS THE REGIONAL
WATERS LATE THIS MORNING...ALLOWING BRIEF SCATTERED SHOWERS OVER
EAST THIRD OF PR. SOME CONVECTION WILL DEVELOP ACROSS THE WESTERN
INTERIOR AND NORTHWEST PR LATER THIS AFTERNOON. MOST OF THE AFTERNOON
CONVECTION WILL BE SHORT-LIVED AND IS EXPECTED TO DISSIPATED BEFORE
SUNSET.

CONDITIONS WILL BECOME MORE CONDUCIVE FOR SHOWER AND THUNDERSTORM
ACTIVITY BY EARLY NEXT WEEK AS A MID-UPPER TROUGH/LOW APPROACHES
THE REGION FROM THE WEST. MOISTURE AND INSTABILITY WILL REMAIN
HIGH MOST OF THE WEEK AS UPPER TROUGH MOVES OVER THE AREA ON
THURSDAY ENHANCING THE MOISTURE CONVERGENCE ACROSS THE LOCAL AREA.
ALTHOUGH...THE POTENTIAL FOR SHOWER DEVELOPMENT INCREASES NEXT
WEEK...NO WIDESPREAD SHOWER ACTIVITY IS EXPECTED AS LITTLE FORCING
IS AVAILABLE FOR THE NEXT 5-7 DAYS.

&&

.AVIATION...VFR CONDS EXPECTED THRU THE FCST PERIOD ACROSS ALL
TERMINALS. HOWEVER...SHRA/TSRA EXPECTED BTW 12/18Z-22Z ACROSS THE
NW QUADRANT OF PR. THIS COULD LEAD TO BRIEF MVFR CONDS AND MTN TOP
OBSCD...IMPACTING MAINLY THE FLYING AREA OF TJBQ/JMZ. LLVL WINDS
WILL PREVAIL FM THE ESE AROUND 15 KT.

&&

.MARINE...SEAS IN THE ATLANTIC WILL INCREASE THROUGH MONDAY WITH
AS A MODERATE NORTHERLY SWELL WILL CONTINUE TO REACH THE LOCAL
ATLANTIC WATERS. SEAS ARE EXPECTED TO REMAIN AROUND 6 FEET OVER
THE NEXT FEW DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 86 76 87 / 20 10 30 10
STT 75 85 75 85 / 20 10 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
604 AM AST SUN DEC 13 2015

.SYNOPSIS...A MID TO UPPER LEVEL TROUGH BUILDING OVER THE WINDWARD
PASSAGE WILL SLOWLY DRIFT EASTWARD INTO THE CENTRAL AND NORTHEAST
ATLANTIC DURING THE UPCOMING WORK WEEK. AS IT MOVES ACROSS THE
REGION...A SERIES OF INDUCED SURFACE TROUGHS WILL COMBINE WITH
THE AVAILABLE LOW LEVEL MOISTURE FROM TODAY INTO EARLY NEXT WEEK
TO ENHANCE SHOWER ACTIVITY.

&&

.DISCUSSION...
SKIES REMAINED MOSTLY CLEAR LATE SATURDAY NIGHT TO PARTLY CLOUDY
EARLY SUNDAY MORNING. SHOWER ACTIVITY WAS OBSERVED MAINLY OVER THE
LOCAL WATERS DURING THE OVERNIGHT HOURS...THEN SOME OF THEM
BRIEFLY MOVED OVER THE EASTERN HALF OF PUERTO RICO AND THE U.S.
VIRGIN ISLANDS EARLY IN THE MORNING. THE COMBINATION OF LOW LEVEL
MOISTURE AND A SURFACE DISTURBANCE IS EXPECTED TO PRODUCE
SCATTERED SHOWERS MAINLY ACROSS THESE AFOREMENTIONED LOCATIONS
DURING THE MORNING HOURS.

A MID TO UPPER LEVEL TROUGH IS EXPECTED TO PRODUCE ENOUGH
DIFFLUENCE ALOFT TO ENHANCE THE DEVELOPMENT OF AFTERNOON
CONVECTION MAINLY OVER THE INTERIOR AND WESTERN SECTIONS OF
PUERTO RICO...AS WELL AS DOWNWIND FROM THE U.S. VIRGIN ISLANDS
AND IN THE VICINITY OF EL YUNQUE AND THE SAN JUAN METROPOLITAN
AREA. THIS ACTIVITY IS EXPECTED TO DIMINISH AROUND SUNSET. PASSING
TRADE WIND SHOWERS ARE EXPECTED TO AFFECT THE EASTERN HALF OF
PUERTO RICO...THE U.S. VIRGIN ISLANDS AND THE LOCAL WATERS SUNDAY
OVERNIGHT INTO THE EARLY MORNING HOURS MONDAY.

FOR THE UPCOMING WORK WEEK...WEATHER CONDITIONS ARE EXPECTED TO
BECOME MORE CONDUCIVE FOR ISOLATED THUNDERSTORMS AND SHOWERS AS A
MID TO UPPER TROUGH/LOW MOVES CLOSE TO THE LOCAL ISLANDS. EACH
DAY...PATCHES OF LOW LEVEL MOISTURE WILL INTERACT WITH THE UPPER
LEVEL FEATURE WHICH WILL ENHANCE THE FORMATION OF TRADE WIND
SHOWERS OVERNIGHT AND EARLY MORNING. ALSO...THE AVAILABLE
INSTABILITY WILL TRIGGER SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS MAINLY ACROSS THE INTERIOR AND WESTERN SECTIONS OF
PR EACH AFTERNOON. ALTHOUGH...THE POTENTIAL FOR SHOWER DEVELOPMENT
INCREASES NEXT WEEK...NO WIDESPREAD SHOWER ACTIVITY IS EXPECTED AS
LITTLE FORCING IS AVAILABLE FOR THE NEXT 5-7 DAYS.

&&

.AVIATION...MAINLY VFR CONDS EXPECTED THRU THE FCST PERIOD ACROSS
ALL TERMINALS. HOWEVER...VCSH PSBL AT TNCM/TKPK/TIST/TISX/EASTERN PR
TERMINALS DUE TO TRADE WIND SHOWERS OVERNIGHT. SHRA/TSRA EXPECTED
BETWEEN 13/18Z-22Z ACROSS THE NW QUADRANT OF PR. THIS COULD LEAD TO
BRIEF MVFR CONDS AND MTN OBSCURATIONS...IMPACTING MAINLY THE FLYING
AREA OF TJBQ/TJMZ. LOW LEVEL ESE WINDS AT 10-20 KT THRU AT LEAST
14/06Z.


&&

.MARINE...SEAS IN THE ATLANTIC WILL CONTINUE TO INCREASE THROUGH
MONDAY AS A MODERATE NORTHERLY SWELL REACHES THE LOCAL ATLANTIC
WATERS. SEAS ARE EXPECTED TO REMAIN AROUND 6 FEET OVER THE NEXT
FEW DAYS. SMALL CRAFT OPERATORS SHOULD EXERCISE CAUTION ACROSS THE
ATLANTIC WATERS AND MONA PASSAGES.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 74 86 75 / 30 30 20 10
STT 85 75 85 75 / 20 30 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
301 PM AST SUN DEC 13 2015

.SYNOPSIS...MID/UPPER LEVEL TROUGH CENTERED OVER EASTERN CUBA WILL
MEANDER OVER THE WINDWARD PASSAGE OVER THE NEXT FEW DAYS BEFORE SLOWLY
MOVE EASTWARD INTO THE CENTRAL AND NORTHEAST CARIBBEAN LATE WEDNESDAY
INTO THURSDAY. AS IT APPROACHES FROM THE WEST...THE CAP INVERSION
WILL ERODE EARLY NEXT WEEK...FAVORING THE MOISTURE TRANSPORT ACROSS
THE LOCAL ISLANDS MOST OF THE WEEK. ALTHOUGH WETTER TRADES ARE
EXPECTED...NO WIDESPREAD SHOWER ACTIVITY IS ANTICIPATED.

&&

.DISCUSSION...MOISTURE HAVE INCREASED ACROSS THE AREA SINCE THIS
MORNING. TJSJ SOUNDING INDICATED 1.29 INCHES OF PRECIPITABLE WATER
WHILE VALUES HAVE INCREASED TO 1.65 THIS AFTERNOON. AS A RESULT...
SCATTERED SHOWERS HAVE BEEN DEVELOPED ACROSS MOST OF THE FORECAST
AREA TODAY. SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO
DEVELOP ACROSS THE WEST INTERIOR AND NORTHWEST PUERTO RICO THIS
AFTERNOON. ISOLATED DEEP CONVECTION IS POSSIBLE OVER NORTHWEST PR
LATER THIS AFTERNOON. MOST OF THE AFTERNOON SHOWER ACTIVITY WILL
TAPER OFF BEFORE SUNSET.

CONDITIONS WILL BECOME MORE CONDUCIVE FOR SHOWER AND THUNDERSTORM
ACTIVITY THROUGH MIDWEEK AS A MID-UPPER TROUGH/LOW APPROACHES THE
REGION FROM THE WEST. INSTABILITY WILL REMAIN HIGH MOST OF THE WEEK
AS UPPER TROUGH MOVES OVER THE AREA ON THURSDAY ENHANCING THE MOISTURE
CONVERGENCE ACROSS THE LOCAL AREA. HOWEVER...NO WIDESPREAD SHOWER
ACTIVITY IS EXPECTED FOR THE NEXT 5-7 DAYS.

&&

.AVIATION...BRIEF MVFR CONDS POSSIBLE ACROSS TJMZ BTW 18-21Z. VFR
CONDS EXPECTED ELSEWHERE. LLVL WINDS WILL PREVAIL FM THE ESE AROUND
15-25 KT.

&&

.MARINE...SEAS IN THE ATLANTIC WILL INCREASE THROUGH MONDAY WITH
AS A MODERATE NORTHERLY SWELL WILL CONTINUE TO REACH THE LOCAL
ATLANTIC WATERS. SEAS ARE EXPECTED TO REMAIN AROUND 6 FEET OVER
THE NEXT FEW DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 86 75 86 / 30 20 10 30
STT 75 85 75 84 / 30 30 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
531 AM AST MON DEC 14 2015

.SYNOPSIS...AT UPPER LEVELS...LOW PRESSURE OVER THE EASTERN END OF
CUBA WILL BECOME LESS WELL DEFINED TUESDAY AND THEN MOVE ACROSS
PUERTO RICO THURSDAY TO FORM A TROUGH ACROSS THE LEEWARD ISLANDS
BY SUNDAY. ANOTHER TROUGH OVER FLORIDA ON SUNDAY IS EXPECTED TO
PINCH INTO ANOTHER LOW IN MUCH THE SAME PLACE AND FORM A TROUGH
OVER THE LOCAL AREA LATER NEXT WEEK.

AT MID LEVELS...HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL
DRIFT SOUTHEAST...AT FIRST...TO JUST NORTH OF THE LEEWARD ISLANDS
TUESDAY NIGHT...THEN GRADUALLY REBUILD AS IT MOVES INTO THE
CENTRAL ATLANTIC. LOW PRESSURE BETWEEN JAMAICA AND CUBA NOW WILL
MOVE OVER THE EASTERN CARIBBEAN BY FRIDAY. PATCHY MOISTURE THIS
WEEK WILL GIVE WAY TO DRIER AIR OVER THE WEEKEND BEFORE BETTER
MOISTURE INVADES FROM THE SOUTHEAST MONDAY.

AT LOWER LEVELS...WEAK HIGH PRESSURE IN THE WESTERN ATLANTIC FADES
UNDER THE PRESSURE OF A LOW RAPIDLY EMERGING OUT OF CANADA AND
DEEPENING OVER THE NORTHEAST CENTRAL ATLANTIC. HIGH PRESSURE WILL
THEN DROP INTO THE CENTRAL ATLANTIC BY SATURDAY WHILE BUILDING. A
STRONGER HIGH WILL EMERGE FROM THE SOUTHEASTERN UNITED STATES
EARLY NEXT WEEK AND REINFORCE THE HIGH PRESSURE NORTH OF PUERTO
RICO. THIS WILL INCREASE THE TRADE WIND FLOW HERE CONSIDERABLY.

&&

.DISCUSSION...MANY SMALL SHOWERS CONTINUE TO MOVE TOWARD THE WEST
AROUND PUERTO RICO AND THE U.S. VIRGIN ISLANDS...BUT OWING TO THE
SHALLOW NATURE OF THE MOISTURE ARE ONLY ABLE TO DROP A FEW
HUNDREDTHS WHERE THEY CROSS LAND. DAYTIME HEATING WILL FAVOR
BETTER CONVECTION WITH ONLY A SLIGHT CHANCE OF THUNDERSTORMS...AND
MAINLY IN THE NORTHWEST PORTION OF PUERTO RICO. HEAVY SHOWERS
COULD AGAIN DEVELOP THERE PRODUCING AREAS OF URBAN AND SMALL
STREAM FLOODING AND POSSIBLY SOME MINOR FLOODING ON THE CULEBRINAS
RIVER...WHICH HAS JUST DROPPED BELOW FLOOD STAGE.

CONDITIONS CHANGE ONLY SLOWLY DURING THE WEEK. SOME ADDITIONAL
MOISTURE AND INCREASING INSTABILITY WILL INDUCE BETTER SHOWERS ON
THURSDAY. A DECREASE IN MOISTURE ON FRIDAY AND A REVERSAL IN
STABILITY WILL YIELD LESS SHOWERS FRIDAY THROUGH SATURDAY
NIGHT...BUT CURRENTLY THE GFS IS FORECASTING A SIGNIFICANT
INCREASE IN MOISTURE ON SUNDAY WITH A WETTER PERIOD EXPECTED
SUNDAY THROUGH AT LEAST TUESDAY.

&&

.AVIATION...MAINLY VFR CONDS ARE EXPECTED DURING THE FCST
PERIOD...WITH VCSH POSSIBLE AT TNCM/TIST/TISX/EASTERN PR TERMINALS
DUE TO TRADE WIND SHOWERS. SHRA/TSRA ARE EXPECTED BETWEEN 14/18Z-22Z
ACROSS THE W SECTION OF PR. AS A RESULT EXPECT BRIEF MVFR CONDS AND
MTN TOP OBSCD...IMPACTING MAINLY THE FLYING AREA OF TJBQ/TJMZ. CALM
TO LIGHT AND VARIABLE WINDS...FOLLOWED BY ESE WINDS AT 10 TO 15 KT
WITH HIGHER GUSTS AND SEA BREEZE VARIATIONS AFT 14/13Z.

&&

.MARINE...SEAS AND SWELL FROM THE NORTH ARE EXPECTED TO SUBSIDE
VERY SLOWLY THROUGH THURSDAY IN THE ATLANTIC. SEAS WILL DIMINISH
THROUGH LATE TUESDAY IN THE CARIBBEAN...BUT CONDITIONS ARE
EXPECTED TO ROUGHEN OVER THE WEEKEND WITH INCREASING WINDS IN
WATERS NORTH AND SOUTH OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 76 87 75 / 30 20 30 30
STT 84 76 85 76 / 30 30 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
232 PM AST MON DEC 14 2015

.SYNOPSIS...A MID TO UPPER LEVEL LOW CENTERED OVER EASTERN CUBA
AND WESTERN HISPANIOLA WILL MEANDER OVER THE WINDWARD PASSAGE UNTIL
MIDWEEK BEFORE SLOWLY MOVE EASTWARD INTO THE NORTHEAST CARIBBEAN
AND THE LEEWARD ISLANDS THURSDAY TROUGH SATURDAY. MOISTURE
WILL INCREASE LATE IN THE UPCOMING WEEKEND AND EARLY NEXT WEEK

&&

.DISCUSSION...ISOLATED TO SCATTERED TRADE WIND PASSING SHOWERS
MOVED FROM THE SURROUNDING WATERS ACROSS THE U.S. VIRGIN
ISLANDS...VIEQUES...CULEBRA AND EASTERN SECTIONS OF PUERTO RICO
DURING THE MORNING AND EARLY AFTERNOON HOURS. THE REST OF THE
ISLAND WAS MOSTLY RAIN FREE MOST OF THE TIME. THIS MOISTURE IS
STILL EXPECTED TO COMBINE WITH DAYTIME HEATING AND LOCAL EFFECTS
WITH THE AID OF THE MID TO UPPER LOW TO INDUCE THE DEVELOPMENT OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS WESTERN...
INTERIOR AND NORTHWEST SECTIONS OF PUERTO RICO LATE THIS
AFTERNOON. THE EAST SOUTHEAST LOW LEVEL WIND FLOW IN COMBINATION
WITH THE CLOSE OR NEAR MID TO UPPER UPPER LOW WILL MAINTAIN THE
SAME WEATHER PATTERN ACROSS THE REGION FOR THE NEXT SEVERAL DAYS.
NOT SIGNIFICANT WEATHER EVENT IS EXPECTED TO AFFECT THE LOCAL
ISLANDS IN THE NEAR FUTURE.

&&

.AVIATION...MAINLY VFR CONDITIONS EXPECTED DURING THE FORECAST
PERIOD ACROSS THE LOCAL FLYING AREA. VCSH POSSIBLE AT TIST/TISX
AND EASTERN PUERTO RICO TERMINALS OVERNIGHT AND EARLY IN THE
MORNING DUE TO TRADE WIND SHOWERS. SHRA/TSRA ARE EXPECTED BETWEEN
15/18Z-22Z ACROSS THE WESTERN PR. CALM TO LIGHT AND VARIABLE
WINDS...FOLLOWED BY ESE WINDS AT 10 TO 15 KT WITH HIGHER GUSTS AND
SEA BREEZE VARIATIONS AFTER 15/13Z.

&&

.MARINE...SAN JUAN BUOY 41053 INDICATED INDICATED 6 FEET SEAS WITH
A PERIOD OF 14 SECONDS AT AROUND 2 PM AST THIS AFTERNOON. SEAS UP
TO 6 FEET AND WINDS UP TO 20 KNOTS ARE EXPECTED TONIGHT. SMALL
CRAFT ARE URGED TO EXERCISE CAUTION ACROSS MOST OF THE COASTAL
WATERS. SWELL FROM THE NORTH ARE EXPECTED TO SUBSIDE VERY SLOWLY
THROUGH THURSDAY IN THE ATLANTIC AND SEAS WILL DIMINISH THROUGH
LATE TUESDAY IN THE CARIBBEAN.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 87 75 88 / 20 20 30 30
STT 76 85 76 84 / 30 20 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
615 AM AST TUE DEC 15 2015

.SYNOPSIS...AT UPPER LEVELS...LOW PRESSURE OVER EASTERN CUBA WILL
CROSS THROUGH PUERTO RICO ON THURSDAY...AND STALL UNTIL EARLY
SUNDAY BEFORE REACHING THE U.S. VIRGIN ISLANDS. A SECOND WEAK
TROUGH WILL CROSS THROUGH THE AREA ON TUESDAY OF NEXT WEEK.

AT MID LEVELS...HIGH PRESSURE BUILDS TO THE NORTHEAST THROUGH THE
WEEKEND. A WEAK TROUGH MOVES OVER THE AREA ON SUNDAY AND CONTINUES
OVER THE EASTERN CARIBBEAN. PASSING POCKETS OF MOISTURE CONTINUE
AT MID LEVELS...BUT STRONG FEATURES ARE ABSENT.

AT LOWER LEVELS...LOW PRESSURE CONTINUES IN THE SOUTHWEST
CARIBBEAN. HIGH PRESSURE WEAKENS TO THE NORTHEAST UNTIL
STRENGTHENING HIGH PRESSURE MOVES FROM CANADA TO THE CENTRAL
ATLANTIC THURSDAY THROUGH SATURDAY. A SECOND HIGH EMERGES FROM THE
SOUTHEASTERN UNITED STATES ON SUNDAY AND BY TUESDAY DOMINATES THE
ENTIRE ATLANTIC OCEAN. THIS HOLDS AND THEN INTENSIFIES EASTERLY
TRADE WIND FLOW OVER THE AREA THROUGH THE PERIOD.

&&

.DISCUSSION...SHOWERS WERE MORE PREVALENT EARLIER LAST NIGHT THAN
THEY WERE AROUND DAWN. ONLY LIGHT AMOUNTS WERE SEEN ON THE EASTERN
SLOPES OF PUERTO RICO AND SAINT CROIX. DRIER AIR MOVED OVER THE
NORTHEASTERN THIRD OF THE FORECAST AREA AND BY 15/0930Z SHOWERS
WERE NOT SEEN ON NATIONAL WEATHER SERVICE RADAR NORTHEAST OF A
LINE FROM SAINT CROIX TO SAN JUAN. SOUTHEAST FLOW IS FORECAST THIS
AFTERNOON AND WILL CONTINUE A PATTERN OF SHOWERS OVER NORTHWEST
PUERTO RICO. WITH LESS MOISTURE IN THE AREA...HOWEVER...AND SOME
HIGH CLOUDS TO LIMIT HEATING...FLOODING IS NOT EXPECTED. THE BAND
OF DRIER AIR HANGING OVER THE NORTHEAST CORNER OF THE FORECAST
AREA WILL FADE AS IT MOVE OVER EASTERN PUERTO RICO WEDNESDAY AND
WILL BE FOLLOWED BY A BAND OF MOISTURE ON THURSDAY THAT WILL
INCREASE RAIN CHANCES...ESPECIALLY IN THE MORNING ON THE
NORTHEASTERN AND EASTERN COAST. THE DRIEST AIR OF THE WEEK MOVES
THROUGH FRIDAY NIGHT...ACCORDING TO THE GFS AND PATCHES OF
MOISTURE FOLLOW IN A MOISTENING TREND THROUGH THE EARLY PART OF
NEXT WEEK THAT SHOULD BRING BETTER SHOWERS. NEVERTHELESS THE
MAINLY EAST SOUTHEAST FLOW THAT PREVAILS UNTIL MID WEEK NEXT WEEK
WILL KEEP LOWER THE POPS ALONG THE NORTH CENTRAL AND NORTHEASTERN
COASTS OF PUERTO RICO WHERE SAN JUAN IS LOCATED AND CONTINUE THE
TREND TOWARD ABOVE NORMAL RAINFALL IN WESTERN AND ESPECIALLY
NORTHWESTERN PUERTO RICO. THE U.S. VIRGIN ISLANDS WILL EXPERIENCE
MAINLY BRIEF PASSING SHOWERS DURING THE PERIOD.

IN THE LAST SEVERAL WEEKS THE GFS HAS PERFORMED FAIRLY WELL
THROUGH THE FIRST 3 TO 4 DAYS. PERFORMANCE AFTERWARD WAS SOMEWHAT
SKETCHY AS HIGH AMPLITUDE PATTERNS AROSE AND BROUGHT FEATURES
THROUGH THAT DID NOT VERIFY. THESE PATTERN ARE NOT APPEARING NOW
AND ONLY CLOUD BANDS PASS THROUGH THAT ARE REMINISCENT OF OLD
FRONTAL BOUNDARIES MOVING IN FROM THE NORTHEAST. THE MODEL NOW
SHOWS MOST OF THE SHOWERS MOVING IN FROM THE CENTRAL ATLANTIC AS
AIR PICKS UP MOISTURE AND HEAT FROM THE SUB-TROPICAL ATLANTIC AND
AVOIDS BRINGING IN THE DRIER AND CLEARER AIR OUT OF THE NORTH. THE
PATCHES OF SHOWERS THAT IT FORECASTS ARE CHARACTERISTIC OF THIS
PATTERN...BUT THEIR TIMING IS QUITE UNRELIABLE AND THEREFORE THE
FORECAST REFLECTS ONLY THE GENERAL TREND.

&&

.AVIATION...VFR CONDS EXPECTED AT ALL TAF SITES WITH VCSH POSSIBLE
AT THE LEEWARD AND USVI TERMINALS AS WELL AS TJSJ EARLY IN THE
MORNING. SHRA AND ISOLATED TSRA EXPECTED BETWEEN 15/18Z-22Z ACROSS
THE W PR...AND MAY RESULT IN BRIEF MVFR CONDS AT TJBQ/TJMZ. CALM TO
LIGHT AND VARIABLE WINDS INCREASING AT 10 TO 15 KT FROM THE
ESE WITH SEA BREEZE VARIATIONS AFT 15/12Z.


&&

.MARINE...SEAS IN THE ATLANTIC ARE SUBSIDING AND NORTHERLY SWELL
DIMINISHES. THIS TREND WILL CONTINUE THROUGH THURSDAY. THEN SWELL
FROM LOW PRESSURE IN THE NORTHWEST ATLANTIC WILL BEGIN TO
ARRIVE...PEAKING ON SUNDAY. SEAS WILL LIKELY APPROACH 7 FEET IN
THE ATLANTIC AND PASSAGES THEN. CARIBBEAN SEAS WILL REMAIN BELOW 7
FEET.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 87 75 / 20 30 20 40
STT 85 76 84 75 / 20 30 20 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
306 PM AST TUE DEC 15 2015

.SYNOPSIS....TUTU LOW OVER HISPANIOLA WILL CONTINUE TO WEAKEN AND
LIFT EAST NORTHEAST ACROSS THE NORTHEASTERN CARIBBEAN OVER THE
NEXT SEVERAL DAYS. THE UPPER TROUGH IS TO THEN RELOCATE OVER THE
NORTHERN LEEWARDS BY SUNDAY. SURFACE HIGH PRESSURE NORTH OF THE
REGION WILL SLOWLY ERODE OVER THE NEXT FEW DAYS...AS A LOW
PRESSURE SYSTEM AND ASSOCIATED COLD FRONT MOVES ACROSS THE WEST
AND NORTHWEST ATLANTIC. THIS SCENARIO WILL LOOSEN THE LOCAL
SURFACE PRESSURE GRADIENT RESULTING IN DECREASING EASTERLY TRADE
WINDS AT LEAST UNTIL THURSDAY. THE SURFACE HIGH WILL BE REINFORCEDONCE
AGAIN BY FRIDAY AND INTO THE UPCOMING WEEKEND AS ANOTHER HIGH
PRESSURE SYSTEM IS FORECAST TO ENTER THE WESTERN ATLANTIC. THIS
PATTERN OF MIGRATORY HIGH PRESSURE SYSTEMS WILL CONTINUE TO
PROPAGATE EASTWARDS ACROSS THE ATLANTIC THROUGH THE WEEKEND.

&&

.DISCUSSION...MOSTLY SUNNY SKIES PREVAILED DURING MUCH OF THE DAY AS
LOW LEVEL MOISTURE ADVECTION CONTINUE TO DECREASE ACROSS THE NORTHEASTERN
CARIBBEAN. A FEW SHOWERS OR AN ISOLATED THUNDERSTORM MAY STILL HOWEVER
DEVELOP LATER IN THE AFTERNOON OVER PARTS OF THE CENTRAL AND WEST
INTERIOR OF PUERTO RICO . SHOWER ACTIVITY HOWEVER WILL BE OF
SHORT DURATION. SKIES WILL BECOME MOSTLY CLEAR DURING THE
OVERNIGHT HOURS WITH ONLY FEW PASSING TRADE WIND SHOWERS EXPECTED
ACROSS THE COASTAL WATERS. DURING THE LATE EVENING AND OVERNIGHT
HOURS FRAGMENTS OF SHALLOW MOISTURE FROM OLD FRONTAL BOUNDARIES
WILL CONTINUE TO MOVE ACROSS THE ATLANTIC IN THE PREVAILING
EASTERLIES. SOME SHOWERS MAY REACH THE EAST COASTAL SHORES BY
EARLY MORNING.

ON WEDNESDAY...LIMITED MOISTURE AVAILABILITY AND INCREASING
STABILITY IN THE UPPER LEVELS WILL GIVE WAY TO MOSTLY FAIR WEATHER
SKIES WITH ONLY SLIGHT CHANCE OF SOME LOCALLY AND DIURNALLY
INDUCED SHOWER DEVELOPMENT ACROSS THE INTERIOR AND WEST SECTIONS
OF PUERTO RICO.

FOR THE END OF THE WEEK AND INTO THE UPCOMING WEEKEND...MOSTLY FAIR
WEATHER SKIES ARE SO FAR SUGGESTED BY THE MOST RECENT MODEL GUIDANCE...
EXCEPT FOR THE INCREASING EASTERLY TRADE WINDS AS THE ATLANTIC
HIGH PRESSURE SYSTEM BUILDS NORTH OF THE REGION AND THE LOCAL
PRESSURE GRADIENT TIGHTENS ACROSS THE NORTHEASTERN CARIBBEAN.

&&

.AVIATION...VFR CONDS EXPECTED AT ALL TAF SITES WITH -SHRA/SHRA
POSSIBLE VCNTY AND OVR PARTS OF THE LEEWARD AND USVI TERMINALS.
SHRA AND ISOLATED TSRA PSBL BETWEEN 16/18Z-22Z ACROSS THE W PR...
AND MAY RESULT IN BRIEF MVFR CONDS AT TJBQ/TJMZ. CALM TO LIGHT
AND VARIABLE WINDS OVERNIGHT.

&&

.MARINE...SEAS ACROSS THE ATLANTIC CONTINUE TO SUBSIDE AS A
NORTHERLY SWELL SLOWLY DIMINISHES. THIS TREND WILL CONTINUE
THROUGH THURSDAY. ANOTHER NORTHERLY SWELL GENERATED FROM A LOW
PRESSURE SYSTEM IN THE NORTHWEST ATLANTIC WILL BEGIN TO ARRIVE
ACROSS THE LOCAL WATER BY THE UPCOMING WEEKEND PEAKING ON SUNDAY.
BY THEN SEAS WILL LIKELY APPROACH 7 FEET IN THE ATLANTIC AND
PASSAGES. CARIBBEAN SEAS WILL REMAIN BELOW 7 FEET DURING THE
ENTIRE PERIOD.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 86 74 85 / 30 20 40 40
STT 74 84 74 84 / 30 20 50 50

[cycloneye]

FXCA62 TJSJ 160928
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
528 AM AST WED DEC 16 2015

.SYNOPSIS...SURFACE HIGH PRESSURE NORTH OF THE REGION WILL SLOWLY
ERODE OVER THE NEXT FEW DAYS...AS A LOW PRESSURE SYSTEM AND
ASSOCIATED COLD FRONT MOVES ACROSS THE WEST AND NORTHWEST
ATLANTIC. THIS SCENARIO WILL LOOSEN THE LOCAL SURFACE PRESSURE
GRADIENT RESULTING IN DECREASING EASTERLY TRADE WINDS AT LEAST
UNTIL THURSDAY. THE SURFACE HIGH WILL BE REINFORCED ONCE AGAIN BY
FRIDAY AND INTO THE UPCOMING WEEKEND AS ANOTHER HIGH PRESSURE
SYSTEM IS FORECAST TO ENTER THE WESTERN ATLANTIC. THIS PATTERN OF
MIGRATORY HIGH PRESSURE SYSTEMS WILL CONTINUE TO PROPAGATE
EASTWARDS ACROSS THE ATLANTIC THROUGH THE WEEKEND.

&&

.DISCUSSION...ONLY LIGHT PASSING SHOWERS WERE NOTED OVER THE
CARIBBEAN WATERS WITH SOME AFFECTING THE SOUTHEAST AND EAST
SECTIONS OF PUERTO RICO. FOR TODAY...DRY WEATHER CONDITIONS WILL
PREVAIL ACROSS THE REGION AS UPPER LEVEL RIDGE CONTINUES
DOMINATING THE LOCAL REGION. ONLY LIGHT PASSING SHOWERS ARE
EXPECTED TO AFFECT THE LOCAL ISLANDS FROM TIME TO
TIME. FOR THIS AFTERNOON...SCATTERED SHOWERS ARE EXPECTED TO
DEVELOP OVER THE WESTERN INTERIOR SECTION OF PUERTO RICO. SOME
THUNDERSTORMS CANT BE RULED OUT.

FOR THE REST OF THE WORK WEEK INTO THE WEEKEND...ONLY PATCHES OF
LOW LEVEL MOISTURE ARE EXPECTED TO AFFECT THE LOCAL AREA.
HOWEVER...NO SIGNIFICANT RAINFALL ACCUMULATION IS EXPECTED. LOCAL
AREA WILL REMAIN UNDER THE INFLUENCE OF AN UPPER LEVEL
RIDGE...WHICH PROMISE TO MAINTAIN STABLE ATMOSPHERIC CONDITIONS
ACROSS THE REGION.

&&

.AVIATION...MOSTLY VFR CONDITIONS EXPECTED ACROSS THE LOCAL FLYING
AREA WITH ONLY VCSH POSSIBLE AT THE USVI TERMINAL AND TJPS EARLY IN
THE MORNING. SHRA AND A COUPLE OF TSRA ARE POSSIBLE BETWEEN 16/18Z-
22Z ACROSS WESTERN PR...AND MAY RESULT IN BRIEF MVFR CONDITIONS AT
TJBQ/TJMZ. LATEST TJSJ SOUNDING INDICATED A SOUTHEAST WIND FLOW UP
TO 20 KNOTS FROM THE SURFACE TO AROUND 15K FEET...BECOMING WESTERLY
AND STRONGER ALOFT.

&&

.MARINE...SEAS UP TO 6 FEET AND WINDS UP TO 20 KNOTS ARE EXPECTED.
SMALL CRAFT SHOULD EXERCISE CAUTION ACROSS THE OFFSHORE ATLANTIC
WATERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 85 74 / 20 40 40 20
STT 84 75 84 74 / 20 40 40 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
315 PM AST WED DEC 16 2015

.SYNOPSIS...TUTT LOW CONTINUED TO MEANDER ACROSS HISPANIOLA
TODAY...BUT WILL SLOWLY WEAKEN AND LIFT EAST NORTHEAST ACROSS THE
NORTHEASTERN CARIBBEAN. IT IS TO THEN RELOCATE OVER THE NORTHERN
LEEWARDS BY SUNDAY. SURFACE HIGH PRESSURE NORTH OF THE REGION WILL
ERODE OVER THE NEXT FEW DAYS AS A LOW PRESSURE SYSTEM AND
ASSOCIATED COLD FRONT MOVES ACROSS THE WEST AND NORTHWEST
ATLANTIC. THIS IN TURN WILL LOOSEN THE LOCAL SURFACE PRESSURE
GRADIENT RESULTING IN DECREASING EASTERLY TRADE WINDS. THE SURFACE
HIGH WILL BE REINFORCED ONCE AGAIN ON FRIDAY AND INTO THE
UPCOMING WEEKEND...AS ANOTHER HIGH PRESSURE SYSTEM WILL ENTER THE
WESTERN ATLANTIC. UNTIL THEN...MIGRATORY HIGH PRESSURE SYSTEMS
WILL CONTINUE TO PROPAGATE EASTWARDS ACROSS THE ATLANTIC THROUGH
THE WEEKEND.

&&

.DISCUSSION...MOSTLY SUNNY SKIES PREVAILED ACROSS THE REGION TODAY.
HOWEVER LOCAL AND DIURNAL EFFECTS AIDED IN THE FORMATION OF SOME
SHOWERS ACROSS PARTS OF THE INTERIOR AND NORTHWEST SECTIONS OF PUERTO
RICO LATE IN THE AFTERNOON. EXPECT THIS ACTIVITY TO QUICKLY DIMINISH
AND DISSIPATED AFTER SUNSET LEAVING CLEAR TO PARTLY CLOUDY SKIES.
DURING THE OVERNIGHT HOURS FEW TRADE WIND SHOWERS WILL MOVE ACROSS
THE COASTAL WATERS. SOME SHOWERS MAY BRUSH THE EAST COASTAL SECTIONS
OF SOME OF THE ISLANDS BY EARLY MORNING.

ON FRIDAY AND INTO THE WEEKEND...SIMILAR WEATHER PATTERN WITH
TYPICALPASSING SHOWERS OVERNIGHT...FOLLOWED BY LIMITED AFTERNOON
CONVECTION ACROSS PARTS OF THE CENTRAL AND WEST SECTIONS OF PUERTO
RICO. SO FAR NO SIGNIFICANT WEATHER FEATURES IN SIGHT FOR THE
WEEKEND...AS MODELS GUIDANCE CONTINUE TO SUGGEST A GRADUAL DRYING
TREND AND OVERALL STABLE UPPER LEVEL ATMOSPHERIC CONDITIONS.
HOWEVER OVER THE WEEKEND AND INTO NEXT WEEK EXPECT INCREASING
EASTERLY TRADE WINDS AS SURFACE HIGH PRESSURE WILL BUILD ACROSS
THE ATLANTIC...AND NORTH OF THE REGION TIGHTENING THE LOCAL
PRESSURE GRADIENT.

&&

.AVIATION...VFR CONDS EXPECTED THROUGH THE FORECAST PERIOD.
TEMPO SHRA EXPECTED AT TJBQ AFTER 16/18Z...VCSH/VCTS POSSIBLE AT
TJMZ/TJSJ AFTER 16/18Z. EASTERLY WINDS AT 10-15KTS WITH SEA BREEZE
VARIATIONS THROUGH 16/22Z...BECOMING LIGHT AND VARIABLE OVERNIGHT
WITH -SHRA ACROSS THE LOCAL AREA...POSSIBLY CAUSING BRIEF VCSH AT
THE LOCAL TERMINALS. WINDS EAST 10-15KT AFTER 17/13Z.

&&

.MARINE...NORTHEASTERLY SWELL WILL CONTINUE TO SUBSIDE ACROSS THE
LOCAL ATLANTIC DURING THE OVERNIGHT HOURS.EXPECT SEAS UP TO 5 FEET
AND WINDS UP TO 15 KNOTS WITH OCCASIONALLY HIGHER GUSTS. ANOTHER
NORTHERLY SWELL IS FORECAST TO ARRIVE AND SPREAD ACROSS THE ATLANTIC
WATERS AND LOCAL PASSAGES OVER THE UPCOMING WEEKEND.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 86 75 87 / 30 30 30 30
STT 75 84 74 85 / 30 30 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
529 AM AST THU DEC 17 2015

.SYNOPSIS...SURFACE HIGH PRESSURE WILL MAINTAIN AN EASTERLY TRADE
WIND FLOW ACROSS THE REGION THROUGH THE WEEKEND. PATCHES OF LOW
LEVEL MOISTURE WILL AFFECT THE REGION FROM TIME TO TIME. TUTT LOW
CONTINUED TO MEANDER ACROSS HISPANIOLA TODAY...BUT WILL SLOWLY
WEAKEN AND LIFT EAST NORTHEAST ACROSS THE NORTHEASTERN CARIBBEAN.

&&

.DISCUSSION...PASSING SHOWERS WERE OBSERVED OVER THE COASTAL
WATERS NORTH OF PUERTO RICO WITH THUNDERSTORMS OBSERVED OVER THE
MONA PASSAGE. THIS ACTIVITY OVER THE MONA PASSAGE IS ASSOCIATED
WITH A TUTT LOW WHICH CONTINUED TO MEANDER ACROSS HISPANIOLA.
HOWEVER...IT WILL SLOWLY WEAKEN AND LIFT EAST NORTHEAST ACROSS
THE NORTHEASTERN CARIBBEAN. AT THE SURFACE...PATCHES OF LOW LEVEL
MOISTURE EMBEDDED IN THE TRADE WIND FLOW WILL AFFECT THE LOCAL
REGION FROM TIME TO TIME THE REST OF THE WORK WEEK INTO THE
WEEKEND. NO CHANGES IN THIS WEATHER PATTERN IS EXPECTED AT LEAST
THROUGH EARLY NEXT WEEK.

&&

.AVIATION...MAINLY VFR CONDITIONS EXPECTED ACROSS ALL
TERMINALS. HOWEVER...VCSH POSSIBLE ACROSS WINDWARD AREAS THRU EARLY
IN THE MORNING...THEN SHRA/TSRA ARE POSSIBLE BETWEEN 18Z-22Z ACROSS
WESTERN PR...AND MAY RESULT IN BRIEF PERIODS OF MVFR CONDITIONS
ACROSS THE FLYING AREA OF TJBQ/TJMZ. LOW LEVEL WINDS WILL CONTINUE
FROM THE EAST AT 10-20 KTS WITH SEA BREEZE VARIATIONS AFTER
14Z...WINDS TURNING SSW-W ABV FL200 AND INCREASING W/HEIGHT.

&&

.MARINE...MODERATE TO LOCALLY FRESH TRADE WINDS WILL PREVAIL ACROSS
THE REGIONAL WATERS DURING THE NEXT SEVERAL DAYS. A NORTHERLY SWELL
IS FORECAST TO ARRIVE AND SPREAD ACROSS THE ATLANTIC WATERS AND
LOCAL PASSAGES OVER THE UPCOMING WEEKEND. SEAS UP TO 5 FEET AND
WINDS 20 KNOTS OR LESS EXPECTED. CRAFT SHOULD EXERCISE CAUTION
ACROSS MOST OF LOCAL WATERS DUE TO WINDS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 87 75 / 20 30 30 20
STT 85 75 85 76 / 20 30 30 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
305 PM AST THU DEC 17 2015

.SYNOPSIS...LATEST GUIDANCE STILL SUGGESTS THAT A SURFACE HIGH
WILL MAINTAIN AN EASTERLY WIND FLOW THROUGH THE WEEKEND...WITH
WINDS INCREASING SLIGHTLY EARLY NEXT WEEK. UPPER TROUGH CONTINUES
OVER THE WESTERN PORTION OF THE LOCAL FORECAST AREA...SLOWLY
WEAKENING AND LIFTING BY SUNDAY. MAINLY BRIEF SHOWERS OVER THE
WATERS AND THE WINDWARD SECTIONS OF THE ISLANDS PLUS SOME
AFTERNOON SHOWERS ACROSS WESTERN PR EXPECTED FOR THE NEXT FEW
DAYS...STRONGER WINDS EARLY NEXT WEEK MAY CAUSE THE SHOWERS TO BE
OF EVEN SHORTER DURATION.

&&

.DISCUSSION...PARTLY CLOUDY SKIES WERE OBSERVED TODAY WITH A FEW
BRIEF SHOWERS ACROSS THE LOCAL WATERS...SOME OF THE SHOWERS
AFFECTED PORTIONS OF EASTERN PR BUT THESE LEFT MINIMAL
ACCUMULATIONS. SOME SHOWERS DEVELOPED ACROSS THE SOUTHWESTERN
QUADRANTOF PR IN THE AFTERNOON...LEAVING ONCE AGAIN VERY LITTLE
ACCUMULATIONS. AVAILABLE MOISTURE IS LIMITED TO THE LOWER LEVELS
FOR THE NEXT FEW DAYS...SOME ADDITIONAL MOISTURE IS EXPECTED OVER
THE AREA ON SUNDAY...LINGERING INTO MONDAY. THIS MEANS THAT THERE
IS A HIGHER CHANCE OF RAIN ON SUNDAY AND MAYBE INTO MONDAY.
THEREAFTER...THE PRESSURE GRADIENT TIGHTENS A BIT AND STRONGER
WINDS WILL BE OBSERVED OVER THE AREA...CAUSING THE SHOWERS THAT DO
DEVELOP TO BE ALSO BRIEF.

&&

.AVIATION...MAINLY VFR CONDS EXPECTED ACROSS ALL TERMINALS DURG
PRD. VCSH OR PSBL SHRA/ISOLD TSRA IN AND AROUND TJBQ AND TJMZ TIL
18/22ZW/BRIEF MVFR IN SHRA. SCT-BKN FL025...FL050...EN ROUTE BTW
ISLANDS AND OVR CTRL AND W PR. L/LVL WNDS FM E 10-25 KTS BLO
FL100. WINDS BCMG SSW-W ABV FL200 AND INCR W/HT. SFC WND MAINLY
ESE 10-15 KTS OCNL HIR GUSTS.

&&

.MARINE...CURRENT CONDITIONS SUGGEST WINDS BELOW 20 KNOTS AND SEAS
AT 5 FEET OR LESS...HOWEVER THE LATEST GUIDANCE SUGGESTS THAT SEAS
MAY BUILD UP TO 6 FEET TONIGHT. SMALL CRAFT SHOULD EXERCISE
CAUTION ACROSS THE ATLANTIC AND CARIBBEAN WATERS AS WELL AS THE
MONA PASSAGE.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 87 75 87 / 30 30 20 20
STT 75 85 76 84 / 30 30 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
543 AM AST FRI DEC 18 2015

.SYNOPSIS...SURFACE HIGH PRESSURE WILL MAINTAIN AN EASTERLY TRADE
WIND FLOW ACROSS THE REGION THROUGH THE WEEKEND. PATCHES OF LOW
LEVEL MOISTURE WILL AFFECT THE REGION FROM TIME TO TIME. TUTT WILL
DISSIPATED SUNDAY.

&&

.DISCUSSION...PASSING SHOWERS WERE OBSERVED OVER THE COASTAL
WATERS NORTH OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS. SOME OF
THESE SHOWERS MOVED ACROSS THE U.S VIRGIN ISLANDS BUT RAINFALL
ACCUMULATIONS WERE NOT SIGNIFICANT. THE UPPER TROUGH IS EXPECTED
TO DISSIPATED ON SUNDAY. AN UPPER LEVEL RIDGE WILL BUILD ACROSS
THE REGION EARLY NEXT WEEK. FOR THE NEXT SEVERAL DAYS...ONLY
ISOLATED TO SCATTERED PASSING SHOWERS ARE EXPECTED ACROSS EASTERN
PUERTO RICO OVERNIGHT AND EARLY IN THE MORNING WITH SOME
CONVECTION EXPECTED TO DEVELOP ACROSS WESTERN PUERTO RICO IN THE
AFTERNOON. HOWEVER ACTIVITY WILL BE OF SHORT DURATIONS AND IN
MOSTLY ISOLATED AREAS LATER IN THE AFTERNOONS.

&&

.AVIATION...MAINLY VFR CONDITIONS EXPECTED ACROSS ALL
TERMINALS. HOWEVER...VCSH EXPECTED ACROSS TNCM/TKPK AND THE USVI
TERMINALS. THEN SHRA EXPECTED BETWEEN 18Z-22Z ACROSS WESTERN
PR...AND MAY RESULT IN BRIEF PERIODS OF MVFR CIGS ACROSS THE FLYING
AREA OF TJBQ/TJMZ. SFC WINDS WILL CONTINUE FROM THE EAST AT 10-15
K`S WITH HIGHER GUSTS AFTER 14Z.

&&

.MARINE...SEAS UP TO 6 FEET AND WINDS UP TO 20 KNOTS ARE EXPECTED
TODAY. SMALL CRAFT SHOULD EXERCISE CAUTION ACROSS MOST LOCAL
WATERS. MARINE CONDITIONS WILL DETERIORATE DURING THE WEEKEND AS
A NORTHEAST SWELL INVADE THE LOCAL WATERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 74 86 75 / 30 20 20 20
STT 86 76 85 75 / 30 30 30 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
253 PM AST FRI DEC 18 2015

.SYNOPSIS...AT UPPER LEVELS...A WEAK LOW NORTH OF HISPANIOLA WILL
DISSIPATE ON SATURDAY AND ITS ASSOCIATED TROUGH WILL PASS THROUGH
PUERTO RICO AND THE U.S. VIRGIN ISLANDS ON SUNDAY. A WEAK TROUGH
WILL DIG OVER THE AREA FROM THE EAST NORTHEAST MID WEEK NEXT WEEK AND
CROSS THE AREA INTO THE CARIBBEAN ON FRIDAY.

AT MID LEVELS...A WEAK TROUGH EXTENDS NORTH OVER HAITI AND MOVES
LITTLE OVER THE WEEKEND. HIGH PRESSURE CONTINUES OVER THE SUB-
TROPICAL ATLANTIC BECOMING STRONGER AFTER WEDNESDAY.

AT LOWER LEVELS...HIGH PRESSURE OVER THE CENTRAL ATLANTIC WILL
MAINTAIN EASTERLY TRADE WINDS OVER PUERTO RICO AND THE U.S. VIRGIN
ISLANDS THROUGH SUNDAY AND THEY WILL CONTINUE WHEN A STRONGER HIGH
PRESSURE MOVES INTO THE WESTERN ATLANTIC EARLY MONDAY. BANDS OF
MOISTURE FROM PRE-FRONTAL BOUNDARIES AS WELL AS OLD FRONTAL
BOUNDARIES THAT HAVE BEEN REPLACED FARTHER NORTH WILL BRING
SHALLOW SHOWERS THROUGH THE ENTIRE NEXT 10 DAYS.

&&

.DISCUSSION...A FEW SMALL SHOWERS PASSED OVER PUERTO RICO AND
STREAMED OFF OF THE U.S. VIRGIN ISLANDS DURING THE MORNING AND
EARLY AFTERNOON. A BAND OF DRIER AIR IS PRESENTLY MOVING INTO
EASTERN PUERTO RICO AND SHOULD CROSS THROUGH EARLY TONIGHT.
THEN...A BAND OF BETTER MOISTURE WILL MOVE SOUTHWEST AS THE
SOUTHEAST FLOW CONTINUES AND WILL BRING SHOWERS TO THE U.S. VIRGIN
ISLANDS AFTER 19/06Z AND TO EASTERN PUERTO RICO AFTER
19/09Z...WITH SOME SHOWERS BEGINNING EARLIER ON THE WINDWARD
SLOPES. THE EAST SOUTHEAST FLOW WILL CONTINUE THROUGH SATURDAY
AND BRING SHOWERS TO THE NORTHWEST PORTION OF PUERTO RICO...BUT
FLOW STRENGTHENS WHEN THE STRONGER HIGH ENTERS THE WATERS NORTH OF
THE AREA AND WINDS BECOME MORE EASTERLY. ALSO MOISTURE INCREASES
CONSIDERABLY AT 850 MB EVEN AS THE AIR BECOMES DRIER ABOVE THAT.
THIS WILL CONTINUE THE PATTERN OF RAPIDLY PASSING
SHOWERS...MAINLY OVER THE U.S. VIRGIN ISLANDS AND ON THE WINDWARD
SIDE OF PUERTO RICO THROUGH NEXT WEEK. FLOODING DOES NOT APPEAR
TO BE INDICATED AT THIS TIME THIS WEEKEND OR NEXT WEEK AND COLD
FRONTS WITH DRIER AIR BEHIND THEM WILL REMAIN WELL NORTH OF THE
AREA. WEAKER BOUNDARIES WILL BRING SUBTLE INCREASES IN SHOWERS
GENERALLY MONDAY AND THURSDAY...BUT TIMING IS DIFFICULT AS THE
BOUNDARIES ARE A RESULT OF COLD FRONTS MOVING INTO THE CENTRAL
ATLANTIC AND WEAKENING TILL ANOTHER PUSHES THEM FARTHER SOUTH WITH
OCEAN MODIFIED AIR BEHIND THEM. EARLY INDICATIONS ARE THAT THIS
PATTERN WILL CONTINUE BEYOND CHRISTMAS DAY.

&&

.AVIATION...MAINLY VFR CONDS EXPECTED ACROSS ALL TERMINALS DURG PRD.
VCSH OR PSBL SHRA/-SHRA OVR THE CTRL MTN RANGE OF PR...AND VCTY
TJSJ... TJBQ...TJMZ TIL 18/22ZW WITH BRIEF MVFR IN SHRA. EN ROUTE BTW
ISLANDS...SCT-BKN FL025...FL050... FEW TCU...TOPS FL140. L/LVL WNDS
FM E 15-25 KTS BLO FL120. SFC WND FM E 10-15 KTS OCNL HIR GUSTS UP
TO 22 KTS.


&&

.MARINE...WINDS AND SEAS WILL INCREASE OVERNIGHT TONIGHT AND AGAIN
MORE ON MONDAY. SEAS ARE EXPECTED TO INCREASE OVER 7 FEET BY
SATURDAY NIGHT AT THE OUTER BUOY AND IN THE OUTER ATLANTIC WATERS
AND LOCAL PASSAGES AS NORTHERLY SWELL OF 3 TO 4 FEET ARRIVES FROM
A STRONG SYSTEM IN THE NORTHERN ATLANTIC.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 86 75 87 / 40 40 20 20
STT 76 85 75 84 / 70 40 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
627 AM AST SAT DEC 19 2015

.SYNOPSIS...SURFACE HIGH PRESSURE ACROSS THE CENTRAL ATLANTIC
WILL CONTINUE TO PROMOTE A MODERATE TO FRESH EASTERLY WIND FLOW
ACROSS THE LOCAL ISLANDS TODAY AND SUNDAY...THEN ANOTHER SURFACE
HIGH PRESSURE WILL MOVE OVER THE WESTERN ATLANTIC ON
MONDAY...TIGHTENING THE PRESSURE GRADIENT AND CAUSING SLIGHTLY
WINDIER CONDITIONS. UPPER LOW TO THE NORTH OF HISPANIOLA WILL
DISSIPATE THROUGH THE DAY TODAY...ANOTHER UPPER TROUGH WILL DIG
ACROSS WESTERN HISPANIOLA EARLY NEXT WEEK. BRIEF SHOWERS EXPECTED
TODAY AND SUNDAY ACROSS THE LOCAL AREA AS MOISTURE INCREASES.

&&

.DISCUSSION...SCATTERED BRIEF SHOWERS AFFECTED THE LOCAL
WATERS...THE USVI AND SMALL PORTIONS OF EASTERN PR OVERNIGHT AND
EARLY IN THE MORNING. THE AVAILABLE MOISTURE HAS BEEN INCREASING
GRADUALLY AND IT IS EXPECTED TO CONTINUE ABOVE THE AVERAGE THROUGH
THE WEEKEND. BRIEF SHOWERS ARE EXPECTED THROUGH THE DAY TODAY
UNDER VARIABLY CLOUDY SKIES. A SIMILAR PATTERN IS EXPECTED FOR
SUNDAY. DRIER AIR IS MOVING IN ON MONDAY AND INTO THE EARLY PART
OF THE UPCOMING WORKWEEK...ALSO THE WINDS ARE EXPECTED TO BECOME
SLIGHTLY STRONGER AS THE PRESSURE GRADIENT TIGHTENS. ISOLATED TO
SCATTERED BRIEF SHOWERS ARE POSSIBLE FOR THE EARLY PART OF NEXT
WEEK. MOISTURE WILL INCREASE LATE NEXT WEEK...WHICH WILL INCREASE
ONCE AGAIN THE CHANCES OF SHOWER ACTIVITY OVER THE LOCAL
AREA.

&&

.AVIATION...MAINLY VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS ALL
TAF SITES THROUGH AT LEAST 19/22Z. HOWEVER...INCREASING CLOUDINESS
WITH SHOWERS ARE EXPECTED ACROSS ALL TERMINALS FROM 19/16Z THROUGH
AT LEAST 20/00Z. BRIEF PERIODS OF MVFR CONDITIONS CAN BE EXPECTED IN
FAST MOVING SHOWERS MAINLY OVER TIST...TISX...TJSJ. SOME MOUNTAIN
OBSCURATIONS EXPECTED THIS AFTERNOON OVER TJMZ AND TJBQ. LOW LEVEL
WINDS WILL BE MAINLY EAST SOUTHEAST AT 15 TO 20 KNOTS.

&&

.MARINE...SEAS WILL BE CHOPPY FOR THE NEXT FEW DAYS AS THE
MODERATE TO FRESH EASTERLY WIND COMBINES WITH THE NORTHERLY SWELL
THAT IS EXPECTED TO INVADE THE LOCAL WATERS TODAY. SMALL CRAFT
SHOULD EXERCISE CAUTION FOR SEAS UP TO 6 FEET TODAY ACROSS THE
LOCAL WATERS. SMALL CRAFT ADVISORY WILL GO INTO EFFECT STARTING
THIS EVENING FOR PORTIONS OF THE LOCAL WATERS AS SEAS BUILD TO 7
FEET TONIGHT.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 85 75 / 40 20 20 40
STT 85 75 85 77 / 40 30 30 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
249 PM AST SAT DEC 19 2015

.SYNOPSIS...AT UPPER LEVELS...WEAK LOW PRESSURE OVER THE EASTERN
DOMINICAN REPUBLIC WILL DISSIPATE AND THE ASSOCIATED TROUGH WILL
SWING THROUGH PUERTO RICO AND THE U.S. VIRGIN ISLANDS ON SUNDAY. A
LONG WAVE TROUGH DEEPENING OVER FLORIDA WILL PINCH OFF ANOTHER
WEAK LOW OVER THE BAHAMAS MONDAY THAT WILL MOVE OVER THE EASTERN
DOMINICAN REPUBLIC BY WEDNESDAY AND SLIDE SOUTH OF THE U.S. VIRGIN
ISLANDS THURSDAY. WEAK LOW PRESSURE WILL REFORM OVER PUERTO RICO
BY SATURDAY.

AT MID LEVELS...HIGH PRESSURE NORTHEAST OF THE AREA IN THE CENTRAL
ATLANTIC WILL RETURN TO THE WESTERN ATLANTIC WITH THE PASSAGE OF A
TROUGH TO THE NORTH BY TUESDAY MORNING. IT WILL CONTINUE IN PLACE
DURING THE WEEK AND THEN MIGRATE ACROSS FLORIDA NEXT WEEKEND.

AT LOWER LEVELS...HIGH PRESSURE OVER THE CENTRAL ATLANTIC WILL BE
REPLACED BY ANOTHER HIGH MOVING INTO THE WESTERN ATLANTIC SUNDAY
NIGHT. THIS WILL REINFORCE THE FRESH TRADE WINDS OVER THE LOCAL
AREA. SURFACE PRESSURE GRADIENTS WILL REMAIN RELATIVELY STRONG
THROUGH THE UPCOMING WEEK. MODERATELY GOOD...BUT SHALLOW MOISTURE
WILL CONTINUE IN THIS TRADE WIND FLOW...BRINGING
BRIEF...SCATTERED...OCCASIONALLY NUMEROUS SHOWERS...TO PUERTO
RICO AND THE U.S. VIRGIN ISLANDS WITH LIGHT ACCUMULATIONS EXPECTED
EACH DAY.

&&

.DISCUSSION...WIDELY SCATTERED SHOWERS MOVED ON MODERATE TO FRESH
TRADE WINDS FROM THE EAST SOUTHEAST ACROSS PUERTO RICO AND THE
U.S. VIRGIN ISLANDS...BRINGING LIGHT RAINFALL AMOUNTS TO THE
WINDWARD COASTS AND SLOPES DURING THE MORNING HOURS. THEN A FEW
SHOWERS DEVELOPED ALONG THE NORTHERN COAST AND MOVED ACROSS THE
INTERIOR OF PUERTO RICO AS OTHER SHOWERS DEVELOPED AROUND SAINT
JOHN AND SAINT THOMAS AND BROUGHT AS MUCH AS TEN TO FIFTEEN
HUNDREDTHS OF AN INCH. SOME SHOWERS ALSO SKIRTED SAINT CROIX AND
CONTINUED RAPIDLY THROUGH THE CARIBBEAN.

WINDS AND MOISTURE AT 850 MB INCREASE SUNDAY AND MONDAY AS THE
SECOND UPPER LEVEL TROUGH FORMS NORTH OF THE WINDWARD PASSAGE.
WINDS AT 850 MB PEAK AGAIN NEAR 30 KNOTS WEDNESDAY EVENING AND
SATURDAY. THIS WILL KEEP A SHOWERY PATTERN IN PLACE FOR MUCH OF
THE WEEK...THOUGH AMOUNTS AND DURATION OF THE SHOWERS WILL BE
MINOR. THE UPPER LEVEL TROUGH APPEARS TO WEAKEN AND PASS SOUTH OF
THE AREA LATE NEXT WEEK...BUT ACCORDING TO THE 19/12Z RUN OF THE
GFS...LOW PRESSURE REFORMS OVER PUERTO RICO AND THE U.S. VIRGIN
ISLANDS FRIDAY...AND DRIFTS VERY SLOWLY NORTHWEST OVER THE
FOLLOWING WEEKEND. THIS WILL ENHANCE A STEADY PARADE OF
BRIEF...SHALLOW PASSING SHOWERS.

&&

.AVIATION...MAINLY VFR CONDITIONS ARE EXPECTED TO PREVAIL THRU THE
FCST PERIOD. HOWEVER...TRADE WIND SHOWERS WILL CONTINUE TO CREATE
VCSH AT LEEWARD ISLANDS/USVI/EASTERN PR TERMINALS THRU EARLY
SUNDAY MORNING. LOW LEVEL WINDS WILL CONTINUE FROM THE EAST AT 10
TO 20 KNOTS. MOUNTAIN OBSCURATIONS SHOULD BE EXPECTED OVER EASTERN
PUERTO RICO...HIGHER GUSTS WILL LIKELY BE ENCOUNTERED...SPCLY
NEAR SHRA.

&&

.MARINE...ALTHOUGH THE WAVE WATCH MODEL APPEARS TO BE
OVER-FORECASTING WINDS AND THEREFORE WAVES...THE GENERAL TREND
WILL BE TO AN INCREASE OF BOTH. IT IS EXPECTED THAT EXPOSED WATERS
WILL BEGIN TO SEE 7 FOOT SEAS IN 15 TO 20 KNOT WINDS. ALTHOUGH THE
MODEL SHOWS UP TO 25 KNOTS IN THE CARIBBEAN AFTER MONDAY WITH 8
FOOT SEAS POSSIBLE WILL HOLD SEAS TO 7 FEET IN THE CARIBBEAN FOR
NOW. SEAS AT THE OUTER BUOY ARE FORECAST TO CONTINUE INCREASING
WITH MODEL FORECASTS OF AROUND 10 FEET BY WEDNESDAY WHEN SEAS OF 8
TO 10 FEET THERE ARE LIKELY. SINCE THE MAIN COMPONENT OF THE SEAS
IS LOCALLY WIND DRIVEN WAVES DO NOT...AT THIS TIME...EXPECT SEAS
OF 10 FEET IN THE LOCAL WATERS.

WOULD EXPECT HIGH RISK OF RIP CURRENTS TO INCREASE THROUGH AT
LEAST TUESDAY ON NORTHERN AND EASTERN COASTS OF PUERTO
RICO...CULEBRA...VIEQUES AND THE U.S. VIRGIN ISLANDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 75 85 75 87 / 30 30 40 40
STT 75 85 77 86 / 40 40 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
522 AM AST SUN DEC 20 2015

.SYNOPSIS...A WEAK UPPER LEVEL TROUGH EXTENDING FROM THE CENTRAL
CARIBBEAN ACROSS PUERTO RICO IS EXPECTED TO DISSIPATES TODAY.
ANOTHER UPPER LEVEL TROUGH IS EXPECTED TO AMPLIFY OVER THE
WESTERN ATLANTIC TODAY AND THEN ACROSS BAHAMAS...EASTERN CUBA
CENTRAL CARIBBEAN BY TUESDAY. SURFACE HIGH PRESSURE ACROSS THE
CENTRAL ATLANTIC IS EXPECTED TO DRIFT EASTWARD AND WILL BE
REPLACED BY ANOTHER HIGH PRESSURE MOVING INTO THE WESTERN
ATLANTIC TONIGHT AND MONDAY.

&&

.DISCUSSION...AN UPPER LEVEL TROUGH ACROSS THE REGION THIS
MORNING...IS EXPECTED TO MOVE EASTWARD WHILE DISSIPATES TODAY.
DOPPLER WEATHER RADAR INDICATED ISOLATED TO SCATTERED TRADE WIND
SHOWERS MOVING RAPIDLY WEST NORTHWESTWARD ACROSS THE U.S. VIRGIN
ISLANDS...VIEQUES...CULEBRA AND ACROSS THE EASTERN AND
SOUTHEASTERN SECTIONS OF PUERTO RICO. DUE TO THE RAPID MOVEMENT OF
THE SHOWERS...THE TOTAL RAINFALL ACCUMULATIONS WERE GENERALLY
MINIMAL. FRAGMENTED PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE
TRADES AND ENHANCED BY THE UPPER LEVEL TROUGH WILL CONTINUE TO
MOVE ACROSS THE REGION THIS MORNING TO RESULT IN BRIEF PASSING
TRADE SHOWERS FROM TIME TO TIME MAINLY ACROSS THE WINDWARD
SECTIONS OF THE ISLANDS AND ACROSS THE LOCAL WATERS. FOR THIS
AFTERNOON...SOME LIMITED CONVECTION IS POSSIBLE ACROSS WESTERN AND
NORTHWEST PUERTO RICO. ANOTHER UPPER LEVEL TROUGH IS EXPECTED TO
AMPLIFY ACROSS CUBA AND THE CENTRAL CARIBBEAN BY MONDAY AND THEN
ACROSS HISPANIOLA AND PUERTO RICO BY MID WEEK. THIS WILL KEEP A
SHOWERY PATTERN ACROSS THE REGION FOR MUCH OF THE WEEK.
HOWEVER...NOT SIGNIFICANT OR WIDESPREAD PRECIPITATION IS EXPECTED.
SURFACE PRESSURE GRADIENTS WILL REMAIN RELATIVELY STRONG THROUGH
THE WEEK.

&&

.AVIATION...TRADE WIND SHOWERS WILL CONTINUE TO CREATE VCSH AT
MOS OF THE LEEWARD ISLANDS/USVI/EASTERN PR TERMINALS THRU THIS
MORNING. LOW LEVEL WINDS WILL CONTINUE FROM THE EAST AT 10 TO 20
KNOTS. MOUNTAIN OBSCURATIONS SHOULD BE EXPECTED OVER EASTERN
PUERTO RICO...HIGHER GUSTS WILL LIKELY BE ENCOUNTERED...SPCLY NEAR
SHRA.

&&

.MARINE...SMALL CRAFT ADVISORIES ARE NOW IN EFFECT FOR MOST OF
THE LOCAL WATERS DUE TO SEAS UP TO 7 FT WITH OCCASIONAL SEAS UP
TO 9 FT AND WINDS AROUND 20 KT. HAZARDOUS MARINE CONDITIONS ARE
EXPECTED TO CONTINUE AT LEAST UNTIL THE FIRST PART OF THE UPCOMING
WORK WEEK. REFER TO LOCAL MARINE PRODUCTS FOR ADDITIONAL
INFORMATION ABOUT THE CURRENT HAZARDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 86 76 / 30 40 40 10
STT 85 76 85 76 / 40 20 20 20

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
300 PM AST SUN DEC 20 2015

.SYNOPSIS...AT UPPER LEVELS...A WEAK TROUGH OVER PUERTO RICO
PASSED THROUGH THIS MORNING AND A MODEST RIDGE WILL FILL IN OVER
THE LOCAL AREA AND MOVE EAST ON MONDAY. AT THE SAME TIME A TROUGH
JUST EAST OF FLORIDA WILL FORM A WEAK LOW NORTH OF HISPANIOLA BY
WEDNESDAY. THIS TROUGH WILL SHIFT EAST THIS WEEK AND CROSS SOUTH
THROUGH PUERTO RICO AND THE U.S. VIRGIN ISLANDS ON THURSDAY. THIS
TROUGH WILL NOT LEAVE THE AREA UNTIL EARLY NEXT WEEK.

AT MID LEVELS...HIGH PRESSURE NORTHEAST OF THE AREA IN THE CENTRAL
ATLANTIC WILL DRIFT WESTWARD TO NORTH OF PUERTO RICO BY THE END OF
THE WEEK. HIGH PRESSURE CONTINUES NORTH OF THE AREA THROUGH THE
REST OF THE WEEK. PATCHES OF VERY DRY AND AND MODESTLY MOIST AIR
WILL DRIFT THROUGH DURING THE NEXT 10 DAYS.

AT LOWER LEVELS...HIGH PRESSURE IN THE WESTERN ATLANTIC AND LOWER
PRESURE OVER COLOMBIA WILL DRIVE FRESH...OCCASIONALLY
STRONG...EASTERLY TRADE WINDS ACROSS THE LOCAL AREA THROUGH MOST
OF THE WEEK. LOWER LEVELS WILL REMAIN QUITE MOIST BELOW 5 KFT
THROUGH THE NEXT 10 DAYS. MOISTURE ABOVE THIS WILL BE
WEAKER...ESPECIALLY ON MONDAY AND ON TUESDAY NIGHT.

&&

.DISCUSSION...SHOWERS IN THE EASTERLY FLOW MOVED QUICKLY ACROSS
PUERTO RICO...DISSIPATING AS THEY MOVED INTO THE INTERIOR
PORTIONS. MORE ARE SEEN BETWEEN CULEBRA AND VIEQUES MOVING ONSHORE
INTO EASTERN PUERTO RICO. ONLY A FEW SHOWERS HAVE FORMED OVER
WESTERN PUERTO RICO. WINDS ARE EXPECTED TO BECOME MORE EASTERLY
TONIGHT AND TOMORROW AND SHOULD ALLOW THE NORTH COAST OF PUERTO
RICO TO HAVE A LITTLE MORE SHOWER ACTIVITY IN THE MORNING. OWING
TO THE VERY MOIST LAYER BELOW 850 MB...SHALLOW SHOWERS WILL
CONTINUE THROUGH MUCH OF THE WEEK...LEAVING ONLY MODEST
ACCUMULATIONS IN THE U.S. VIRGIN ISLANDS AND EASTERN PUERTO RICO AND
SLIGHT ACCUMULATIONS IN WESTERN PUERTO RICO. WINDS WILL CONTINUE
TO INCREASE THROUGH TUESDAY IN THE LOWER LAYERS. 850 MB WINDS ARE
EXPECTED TO PEAK NEAR 30 KNOTS MONDAY NIGHT AND NEAR 31 KNOTS
WEDNESDAY NIGHT. THEREFORE SURFACE WINDS WILL CONTINUE TO BE
MODERATE TO FRESH. TEMPERTURES WILL CONTINUE CLOSE TO SLIGHTLY
ABOVE NORMAL.

&&

.AVIATION...MAINLY VFR CONDITIONS ARE EXPECTED TO PREVAIL THRU THE
FCST PERIOD. HOWEVER...-SHRA EN ROUTE FM THE LEEWARD ISLANDS THRU
THE USVI/EASTERN PR TERMINALS WILL CONTINUE TO CREATE PERIODS OF
VCSH THRU MONDAY MORNING. MOUNTAIN OBSCURATIONS CAN BE EXPECTED OVER
EASTERN PUERTO RICO AS SOME SHOWERS COULD MOVE INLAND OVERNIGHT. SFC
WINDS OVERNIGHT WILL BE LIGHT AND VARIABLE. HOWEVER...WINDS BLO
FL150 WILL CONTINUE FROM THE EAST AT 10 TO 22 KNOTS.

&&

.MARINE...WINDS AND SEAS WILL INCREASE THROUGH MONDAY AND SMALL
CRAFT ADVISORIES GO UP FOR MOST WATERS EXCEPT THOSE HUGGING THE
SOUTHERN AND WESTERN COASTS OF PUERTO RICO. WIND GUSTS EARLY THIS
WEEK ARE EXPECTED BETWEEN 20 TO 30 KNOTS OVER THE WATERS WITH THE
HIGHEST WINDS. CONDITIONS WILL IMPROVE A LITTLE AFTER THURSDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 74 83 75 84 / 40 50 30 40
STT 75 81 75 81 / 30 30 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
556 AM AST MON DEC 21 2015

.SYNOPSIS...ALTHOUGH TROFINESS ALOFT WILL PREVAIL THROUGH
MIDWEEK...A LOW TO MID LEVEL RIDGE PATTERN WILL DOMINATE THE
LOCAL AREA. RIDGE PATTERN WILL HOLD MUCH OF THIS WEEK. FRESH
TO LOCALLY STRONG TRADE WINDS EXPECTED THROUGH AT LEAST
SATURDAY.

&&

.DISCUSSION...CLEAR TO PARTLY CLOUDY SKIES WERE OBSERVED ACROSS
THE LOCAL ISLANDS DURING THE OVERNIGHT AND EARLY MORNING HOURS.
BRIEF SHOWERS WERE OBSERVED ACROSS THE USVI AND EASTERN PUERTO
RICO WITH MINIMAL RAINFALL ACCUMULATIONS SO FAR. WINDS WERE LIGHT
AND VARIABLE...AND THE OVERNIGHT MINIMUM TEMPERATURES WERE IN THE
LOW TO MID 70S ACROSS THE LOWER ELEVATIONS.

ALTHOUGH TROFINESS WILL PREVAIL THROUGH MIDWEEK...ENVIRONMENTAL
CONDITIONS ARE NOT FAVORABLE FOR ORGANIZED CONVECTION AS A LOW
TO MID LEVEL RIDGE PATTERN HOLDS ACROSS THE AREA. FRESH TO LOCALLY
STRONG TRADE WINDS WILL PREVAIL MUCH OF THIS WEEK WITH PRECIPITABLE
WATER VALUES NEAR OR BELOW NORMAL. THEREFORE...UNDER A RIDGE
PATTERN...BREEZY CONDITIONS AND NEAR NORMAL PRECIPITABLE WATER...
TRADE WIND SHOWERS WILL PREVAIL ACROSS THE LOCAL AREA A EACH DAY
WITH LIMITED AFTERNOON CONVECTION ACROSS WEST PUERTO RICO.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE FCST
PERIOD. -SHRA FROM THE LEEWARD ISLANDS THROUGH THE USVI/EASTERN PR
TERMINALS WILL CREATE PERIODS OF VCSH THRU 21/13Z. SHRA POSSIBLE TO
AFFECT TJMZ BETWEEN 21/18Z AND 21/22Z. SFC WINDS INCREASING AFTER
21/14Z FROM THE EAST AT UP TO 15-20 KTS...LIGHTER AT TJPS AND
TJMZ.

&&

.MARINE...A NORTHERLY SWELL AND FRESH EASTERLY WINDS WILL CONTINUE
TO RESULT IN HAZARDOUS MARINE CONDITIONS ACROSS THE LOCAL WATERS
TODAY. SEAS 5 TO 7 FEET WITH OCCASIONAL SEAS UP TO 9 FEET. NORTHEAST
SWELL 4 TO 7 FEET. EASTERLY WINDS 15 TO 20 KNOTS. THEREFORE SMALL
CRAFT ADVISORIES IN EFFECT FOR MOST OF LOCAL WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 86 74 / 30 20 30 20
STT 86 76 86 76 / 20 20 30 20