Caribbean - Central America Weather

[cycloneye]

A tropical wave located just offshore the west coast of Africa is
producing disorganized shower activity. Some gradual development of
this wave is possible by early next week while it moves generally
westward across the tropical Atlantic at about 15 mph.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...medium...40 percent

[lordkev]

The remnants of Grace are beginning to affect us here in St Kitts. It's getting quite gusty. Really hoping it brings some rain as our water has been getting turned off each night for rationing.

[cycloneye]

2 PM TWO up to 50%.

A tropical wave located between west Africa and the Cape Verde
Islands is producing minimal shower activity. Environmental
conditions are forecast to become favorable for some gradual
development of this wave by early next week while it moves generally
westward across the tropical Atlantic at about 15 mph.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...medium...50 percent

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
315 PM AST FRI SEP 11 2015

.SYNOPSIS...AN AMPLIFY UPPER TROUGH OVER THE MONA PASSAGE WILL
HOLD OVER THE NEXT SEVERAL DAYS. TROUGH PATTERN ALOFT WILL COMBINE
WITH REMNANTS OF GRACE TO PRODUCE NUMEROUS SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS PORTIONS OF U.S. VIRGIN ISLANDS AND PUERTO
RICO THROUGH SATURDAY. WEATHER CONDITIONS WILL IMPROVE GRADUALLY
SATURDAY NIGHT INTO SUNDAY MORNING AS DRIER AIR WILL SPREAD OVER
THE FORECAST AREA.

&&

.DISCUSSION...A TROPICAL WAVE...INCLUDING THE REMNANTS OF GRACE...
IS MOVING WESTWARD AT 15 TO 20 KT...SLOWER THAN THIS MORNING. AS
A RESULT...WEATHER CONDITIONS WILL DETERIORATE THE REST OF TODAY
AND TONIGHT AS DEEPER MOISTURE AND INSTABILITY SPREADS OVER THE
REGION. A MAXIMUM OF RELATIVE VORTICITY ACCOMPANIED THIS TROPICAL
WAVE...BASICALLY ANOTHER MECHANISM TO TRIGGER SHOWERS AND
THUNDERSTORMS ACROSS USVI AND PR LATE TONIGHT. AFOREMENTIONED
UPPER TROUGH ALSO HELPS TO ENHANCE THE CONVECTIVE INSTABILITY
ACROSS THE ISLANDS. THEREFORE...ACTIVE WEATHER IS FORECAST ACROSS
THE REGION OVER THE NEXT 24 HOURS. THE BEST MOISTURE CONVERGENCE
IS EXPECTED ACROSS THE USVI...CULEBRA...VIEQUES AND THE EASTERN
HALF OF PUERTO RICO. SO...THE POTENTIAL OF HEAVY RAINS...STRONG
GUSTY WINDS AND URBAN AND LOW LYING FLOODING REMAIN HIGH FOR USVI
AND PR THROUGH SATURDAY AFTERNOON.

MID LEVEL RIDGE WILL STRENGTHEN ACROSS THE NORTHEAST CARIBBEAN...
RESULTING IN DRIER AND MORE STABLE CONDITIONS SUNDAY. THEREFORE...
GENERALLY FAIR WEATHER CONDITIONS ARE EXPECTED TO PREVAIL SUNDAY
THROUGH AT LEAST TUESDAY.

&&

.AVIATION...BRIEF PERIODS OF MVFR CONDITIONS IS EXPECTED DURING THE
REST OF THE AFTERNOON ACROSS THE LOCAL FLYING AREA...AS THE MOISTURE
ASSOCIATED WITH THE REMNANTS OF T.S. GRACE MOVES ACROSS THE REGION.
SHRA/TSRA ARE EXPECTED TO INCREASE ACROSS THE U.S.V.I. AND EASTERN
PUERTO RICO AFTER 11/22Z AS MOISTURE PROPAGATES WESTWARD ACROSS THE
REGION AND THEN WILL MOVE INTO THE INTERIOR AND WESTERN SECTIONS OF
PR AFTER 12/02Z. MTNS OBSCD...LOW CEILING AND MVFR DUE TO SHRA/TSRA
ARE EXPECTED OVER MOST OF THE TAF SITES. SFC WINDS AT 10-20 KT ARE
EXPECTED WITH HIGHER GUSTS SPECIALLY NEAR SHOWERS AND
THUNDERSTORMS.

&&

.MARINE...SEAS UP TO 6 FEET AND WINDS OF 20 KNOTS WILL CONTINUE
THIS AFTERNOON ACROSS THE COASTAL WATERS. WINDS AND SEAS EXPECTED
TO INCREASE THIS EVENING AND OVERNIGHT AS SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THE REMNANTS OF GRACE PROPAGATES WESTWARD ACROSS
THE REGIONAL WATERS.

&&

.HYDROLOGY...THE POTENTIAL FOR BENEFICIAL RAINS ARE EXPECTED OVER
THE NEXT FORECAST PERIOD...RAINFALL AMOUNTS OF 1 TO 3 INCHES WITH
LOCALIZED HIGHER AMOUNTS ARE FORECAST. DUE TO THIS EXPECTED
RAINFALL...SOME SIGNIFICANT WITHIN BANK RISES CAN BE EXPECTED ON
THE LARGER RIVERS AND STREAMS ACROSS THE FORECAST AREA. FOR THE
SMALLER STREAMS AND URBAN AREAS INCLUDING THE DRY GUTS OF THE U.S.
VIRGIN ISLANDS...SOME MINOR TO MODERATE FLOODING CAN BE EXPECTED.
ALSO...IN WESTERN PUERTO RICO WHERE SOILS ARE SATURATED AND SOME
STREAM AND RIVER LEVELS ARE HIGH...THERE IS ALSO A POTENTIAL FOR
MINOR TO MODERATE FLOODING.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 90 78 91 / 80 60 40 40
STT 80 88 80 90 / 80 70 30 30

[cycloneye]

8 PM TWO:

A tropical wave located southeast of the Cape Verde Islands is
producing minimal shower activity. Environmental conditions are
forecast to become favorable for some gradual development of this
wave by early next week while it moves generally westward across the
tropical Atlantic at about 15 mph.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...medium...50 percent

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
539 AM AST SAT SEP 12 2015

.SYNOPSIS...AN AMPLIFIED UPPER TROUGH OVER THE MONA PASSAGE WILL
HOLD OVER THE AREA AT LEAST UNTIL EARLY NEXT WEEK. THE TROUGH
PATTERN ALOFT WILL COMBINE WITH REMNANTS OF GRACE TO PRODUCE
SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF THE U.S. VIRGIN
ISLANDS AND PUERTO RICO THROUGH THIS EVENING. WEATHER CONDITIONS
WILL IMPROVE GRADUALLY SATURDAY NIGHT INTO SUNDAY MORNING AS DRIER
AIR WILL SPREAD OVER THE FORECAST AREA. ANOTHER TROPICAL WAVE IS
EXPECTED TO REACH THE LOCAL AREA BY MID WEEK NEXT WEEK.

&&

.DISCUSSION...THE FOCUS OF THE BEST CONVECTIVE ACTIVITY WAS
DETECTED OVER THE CARIBBEAN WATERS AND ANEGADA PASSAGE. SOME BANDS
WITH MODERATE TO HEAVY RAINFALL AND GUSTY WINDS REACHED THE LOCAL
ISLANDS OVERNIGHT AND EARLY IN THE MORNING. THE LOCAL NETWORK
DETECTED STRONG THUNDERSTORMS WITH STRONG GUSTY WINDS OF UP TO 45
MPH AT TIMES. IN ADDITION...THE RAINGAGES AT CARRAIZO AND LA PLATA
BASIN REPORTED UP TO 0.48 INCHES OF RAIN IN THE LAST 12 HOURS.

AN UPPER LEVEL TROUGH WILL INTERACT WITH THE TROPICAL WAVE
MOISTURE TO INCREASE THE CHANCE FOR SHOWER AND THUNDERSTORM
ACTIVITY ACROSS THE REGION THROUGHOUT THE DAY. AS RESULT...
EXPECT MOSTLY CLOUDY SKIES WITH PASSING SHOWERS FROM TIME TO TIME
ACROSS MOST OF THE LOCAL AREA TODAY. IN ADDITION...SQUALLY WEATHER
WITH MODERATE TO HEAVY RAINFALL ACTIVITY AND GUSTY WINDS CAN ALSO
BE EXPECTED ACROSS THE REGION.

MODELS HAVE OVERDONE THE RAINFALL ACTIVITY ACROSS THE
REGION...HOWEVER THE GFS STILL INSISTS IN A HIGH POTENTIAL FOR
SHOWERS AND THUNDERSTORMS ACROSS THE REGION TODAY. THE MAXIMUM
RAINFALL ACCUMULATIONS HAVE BEEN OBSERVED WELL SOUTH OVER THE
CARIBBEAN WATERS. THERE IS SOME PROMISE OF GOOD CONVECTION
DEVELOPING OVER PUERTO RICO THIS AFTERNOON...BUT IT SHOULD BE
NOTED A DENSE LAYER OF CLOUDINESS OVER THE REGION COULD INHIBIT
THE AMOUNT OF SOLAR RADIATION AND THE AFTERNOON CONVECTION.
HOWEVER...THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS DURING THE
AFTERNOON HOURS IS STILL HIGH.

WEATHER CONDITIONS WILL IMPROVE GRADUALLY TONIGHT INTO SUNDAY
MORNING AS DRIER AIR SPREADS OVER THE FORECAST AREA. BUT EACH DAY
AFTERNOON CONVECTION CAN BE EXPECTED MAINLY OVER THE INTERIOR AND
WESTERN SECTIONS OF PUERTO RICO...UNTIL THE ARRIVAL OF THE NEXT TROPICAL
WAVE...THAT IS EXPECTED TO REACH THE LOCAL AREA BY MID NEXT WEEK.

&&

.AVIATION...THE BACK EDGE OF THE BEST MOISTURE FROM TROPICAL WAVE
IS MOVING ACROSS THE LEEWARD ISLANDS...CONDS WILL IMPROVE TO
PREVAILING VFR AFT 12/09Z WITH VCSH CONTG AND A POSSIBILITY OF
TSRA AFT 12/16Z. SHRA DCRG ARND TISX AND TIST AFT 12/18Z TO
PREVAILING VFR. PREVAILING VFR OVR PR TIL 12/16Z XCP VCNTY TJPS
AND E-S COASTS TIL 12/10Z MVFR CIGS/VSBYS IN +SHRA STREAMING
ACROSS. GUSTY WINDS TO 35 KNOTS ARE POSSIBLE IN SHRA/TSRA. AFT
12/16Z SHRA/TSRA DVLPG WEST AND INTERIOR PORTIONS PR LCL MVFR/IFR
FOR CIG/VIS. MTN OBSCURATIONS TO CONTINUE THROUGH THE PD. WINDS
ALF UP TO FL150 ESE 15 TO 25 KT INCRG TO 15 TO 30 KT BY 13/00Z AND
BCMG SE.

&&

.MARINE...SEAS ACROSS THE OFFSHORE WATERS AND ANEGADA PASSAGE ARE
EXPECTED TO BE BETWEEN 5-7 FEET WITH OCCASIONAL SEAS UP TO 9 FEET.
A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE ANEGADA PASSAGE...THE
CARIBBEAN AND ATLANTIC OFFSHORE WATERS UNTIL 8AM AST. SQUALLY
WEATHER IS EXPECTED ACROSS ALL WATERS DURING THE NEXT 12-18 HOURS
AS THE TROPICAL WAVE EXITS THE LOCAL AREA TONIGHT.

&&

.HYDROLOGY...THE POTENTIAL FOR BENEFICIAL RAINS ARE EXPECTED OVER
THE NEXT FORECAST PERIOD...RAINFALL AMOUNTS OF 1 TO 3 INCHES WITH
LOCALIZED HIGHER AMOUNTS ARE FORECAST. DUE TO THIS EXPECTED
RAINFALL...SOME SIGNIFICANT WITHIN BANK RISES CAN BE EXPECTED ON
THE LARGER RIVERS AND STREAMS ACROSS THE FORECAST AREA. FOR THE
SMALLER STREAMS AND URBAN AREAS INCLUDING THE GUTS OF THE U.S.
VIRGIN ISLANDS...SOME MINOR TO MODERATE FLOODING CAN BE EXPECTED.
ALSO...IN WESTERN PUERTO RICO WHERE SOILS ARE SATURATED AND SOME
STREAM AND RIVER LEVELS ARE HIGH...THERE IS ALSO A POTENTIAL FOR
MINOR TO MODERATE FLOODING AND MUDSLIDES.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 79 90 79 / 50 40 40 30
STT 90 82 90 80 / 60 30 30 30

[Gustywind]

Good news Guadeloupe and the Northern Leewards have back off the yellow alert related to Grace's remnants...
Here is a recap of this active twave ( ex TS Grace as a an active twave spreading on Guadeloupe).

http://www.meteofrance.gp/integration/s ... eloupe.pdf

Track No. 4 for Guadeloupe bulletin

Saturday, September 12, 2015 at 0559 AM

Episode n ° 6-GD

Ended event

Level of vigilance: return to green

Current situation: Our archipelago is now at the back of the wave tropical active (remnants of the old storm
tropical Grace).

This morning, potentially stormy showers may still reach Guadeloupe. However their impact will be less than precipitation of yesterday. Then a quieter time moved and the stormy risk fades.

Data observed during the episode:

-40 mm at Bellevue Pointe-Noire.

-Terre-de-Bas Les Saintes 51 mm

-Radar estimate: 80-100 mm on the east coast between the localities of le Moule and St-François.

-Very important electrical activity: many rumbles of thunder heard and lightning observed during the episode, a home
has been blasted at Chauvel Abymes (TV source from Guadeloupe 1ere)

See how strong a tstorm destroyed the electrical system in a house http://guadeloupe.la1ere.fr/emissions/j ... direct-ici

[Gustywind]

I can tell you really that the convective activity was sometimes pretty intense . All the islanders in the path of this twave should be vigilant and aware! This thing is not a Gameboy so be on your guard....
Just speaking about that a robust line of showers is spreading on me, a strong gust is coming and the thunder is rumbling nicely.
I will keep you informed if i've more... but don't forget what i say...

[Gustywind]

Blessing remnants of ex Grace on the Northern Leewards... as they received only 2 millimeters
Unhopefully the drought situation continues... what a pity! Be courageous Msbee, keeping our fingers crossed and hoping that the next system could bring much more rain if if this systems maintains something decent and progresses towards the Leewards, but we're maybe far away from our wishes and the reality. Time will tell. Wait and see.

http://www.meteofrance.gp/integration/s ... s_nord.pdf

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
317 PM AST SAT SEP 12 2015

.SYNOPSIS...THE AXIS OF THE TROPICAL WAVE WAS NOW OVER THE MONA
CHANNEL THIS AFTERNOON...WITH DEEP TROPICAL MOISTURE STILL TRAILING
AND EXTENDING OVER THE LOCAL AREA. TUTT LOW AND ASSOCIATED TROUGH
JUST WEST OF THE REGION...EXTENDING SOUTHWEST OVER HISPANIOLA...
WILL CONTINUE TO LIFT FARTHER WEST...AND GRADUALLY WEAKEN AS THE
HIGH PRESSURE RIDGE ALOFT...BUILDS AND SPREADS ACROSS THE REGION
FROM THE SUBTROPICAL ATLANTIC. SATELLITE IMAGERY SHOWED CONSIDERABLE
MID TO HIGH LEVEL CLOUDINESS DRAPED ACROSS THE REGION AS PERSISTENT
SOUTHWESTERLY FLOW ALOFT CONTINUED TO TRANSPORT MID TO UPPER LEVEL
CLOUD DEBRIS ACROSS THE REGION.

&&

.DISCUSSION...SKIES REMAINED MOSTLY CLOUDY ACROSS THE AREA TODAY AS
THE THICK LAYERS OF MID TO UPPER LEVEL CLOUDS SHIELDED MOST OF THE
FORECAST AREAS FORM DIRECT SUNLIGHT. THIS AIDED IN SUPPRESSING AND
LIMITING CONVECTIVE DEVELOPMENT ACROSS THE ISLANDS AND COASTAL
WATERS. BY LATE AFTERNOON...A FEW BREAKS IN CLOUDINESS LEAD TO
RAPID DEVELOPMENT OF SHOWERS AND SOME THUNDERSTORMS ACROSS
EASTERN PUERTO RICO ...AND OVER THE COASTAL WATERS JUST OFF THE
COAST OF PUERTO RICO BETWEEN CULEBRA AND VIEQUES. SO FAR LITTLE
OR NO CONVECTIVE ACTIVITY WAS DETECTED OR REPORTED ACROSS THE
REMAINDER OF THE ISLANDS. EXPECT THE CLOUDINESS ACROSS THE REGION
TO TAPER OFF GRADUALLY DURING THE LATE EVENING AND OVERNIGHT HOURS
INTO SUNDAY MORNING...LEAVING VARIABLY CLOUDY TO PARTLY CLOUDY
SKIES AND DECREASING SHOWER ACTIVITY OVER LAND.

DUE TO THE TRAILING MOISTURE FROM THE DEPARTING TROPICAL WAVE AND
THE PROXIMITY OF THE TUTT ...EXPECT ANOTHER ROUND OF CONVECTIVE
DEVELOPMENT ACROSS PORTIONS OF THE COASTAL WATERS OVERNIGHT.
DURING THE OVERNIGHT AND INTO THE EARLY SUNDAY MORNING...SOME
SHOWERS WILL AFFECT PORTIONS OF THE ISLANDS. WIDESPREAD RAINFALL
IS HOWEVER NOT EXPECTED AT THIS TIME. BY SUNDAY AFTERNOON AND
INTO MONDAY...A GRADUAL IMPROVEMENT IN THE WEATHER AND SKY
CONDITIONS IS FORECAST...AS DRYER AIR WILL MOVE IN ACROSS THE
AREA.

LOCAL AND DIURNAL EFFECTS WILL AID IN SOME AFTERNOON CONVECTION
EACH DAY...MAINLY OVER PARTS OF THE INTERIOR AND WEST SECTIONS OF
PUERTO RICO...AS WELL AS IN ISOLATED SPOTS ACROSS THE U.S.VIRGIN
ISLANDS. THE NEXT TROPICAL WAVE IS FORECAST TO MOVE ACROSS THE
REGION BY TUESDAY AND WEDNESDAY... WITH LATEST MODEL GUIDANCE
STILL SUGGESTING A RAPID INCREASE IN LAYERED PRECIPITABLE WATER IN
EXCESS OF TWO INCHES BY THAT TIME. THEREFORE...BETTER CHANCE FOR
ADDITIONAL RAINFALL ACROSS THE ISLANDS. AS USUAL...WILL CONTINUE
TO MONITOR THE WEATHER PATTERN AND MODEL GUIDANCE AND SEE HOW THIS
UNFOLDS.

&&

.AVIATION...PREVAILING VFR CONDS EXPECTED ACROSS THE LOCAL
TERMINALS THROUGH THE FORECAST PERIOD WITH LIKELY VCSH AND CIGS
AROUND FL070 UNTIL 13/00Z. THEREAFTER...CIGS WILL START TO CLEAR
GRADUALLY STARTING FROM TNCM AND TKPK THEN THE USVI AND EASTERN
PR. SHRA/TSRA ACROSS CENTRAL INTO WESTERN PR EXPECTED UNTIL
12/22Z...CAUSING POSSIBLE VCTS AT TJSJ UNTIL 12/20Z AND THEN
TJPS/TJBQ/TJMZ LATER IN THE AFTERNOON. EASTERLY WINDS AT AROUND
10-15KTS WITH LOCAL VARIATIONS AT TJMZ/TJPS...DECREASING OVERNIGHT
TO AROUND 5-10 KTS.

&&

.MARINE...SMALL CRAFT SHOULD EXERCISE CAUTION MAINLY ACROSS THE
OFFSHORE COASTAL WATERS AND LOCAL PASSAGES...AS OCCASIONAL SEAS
ARE EXPECTED TO BE UP TO 6 FEET AND WINDS UP TO 20 KNOTS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 79 92 / 40 40 30 30
STT 82 90 80 90 / 40 40 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
526 AM AST SUN SEP 13 2015

.SYNOPSIS...THE LINGERING MOISTURE AND CLOUDS ASSOCIATED WITH
YESTERDAYS TROPICAL WAVE ARE EXPECTED TO LEAVE THE AREA EARLY
THIS MORNING. A TUTT LOW AND ASSOCIATED TROUGH JUST WEST OF THE
REGION...OVER HISPANIOLA...WILL CONTINUE TO LIFT FARTHER
WEST...AND GRADUALLY WEAKEN AS A HIGH PRESSURE RIDGE
ALOFT...BUILDS AND SPREADS ACROSS THE REGION FROM THE SUBTROPICAL
ATLANTIC. THE NEXT TROPICAL WAVE IS EXPECTED TO REACH THE LOCAL
AREA BY TUESDAY NIGHT AND WEDNESDAY.

&&

.DISCUSSION...SATELLITE IMAGERY SHOWED CONSIDERABLE MID TO HIGH
LEVEL CLOUDINESS WITH EMBEDDED SHOWERS AND THUNDERSTORMS MAINLY
ACROSS THE WESTERN HALF OF PUERTO RICO...THE CARIBBEAN...ATLANTIC
AND THE MONA PASSAGE. ALSO..DRY AIR ADVECTION CAN BE SEEN ENTERING
THE U.S. VIRGIN ISLANDS AND THE EASTERN HALF OF PUERTO RICO.

MOSTLY CLOUDY SKIES WITH PASSING SHOWERS FROM TIME TO TIME
PREVAILED ACROSS MOST OF THE ISLANDS OF PUERTO RICO AND THE U.S.
VIRGIN ISLANDS OVERNIGHT. FLOOD ADVISORIES WERE ISSUED FOR THE
MUNICIPALITIES OF ADJUNTAS... PENUELAS...PONCE...SAN
LORENZO...CAGUAS...AND JUNCOS DUE TO THUNDERSTORMS WITH HEAVY
RAIN. IN ADDITION DURING THE LAST 24 HOURS...CARRAIZO RAIN GAGES
RECORDED BETWEEN 1 AND 3.34 INCHES OF RAIN AND LA PLATA SENSORS
BETWEEN 0.19 AND 0.42 INCHES OF RAIN.

SHOWER ACTIVITY IS EXPECTED TO DIMINISH SLOWLY AS DRY AIR
ADVECTION REACHES THE LOCAL AREA. THEREFORE...HUMID AND WARMER
CONDITIONS ARE EXPECTED LATE SUNDAY MORNING AND INTO THE
AFTERNOON. ANOTHER ROUND OF SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED OVER THE CORDILLERA CENTRAL AND WESTERN SECTIONS OF
PUERTO RICO DURING THE AFTERNOON HOURS. HOWEVER...ELSEWHERE...
PARTLY CLOUDY SKIES ARE EXPECTED TO DECREASE AS THE LINGERING
MOISTURE AND CLOUDS ASSOCIATED WITH THE TROPICAL WAVE...NOW OVER
HAITI...WILL MOVE AWAY FROM THE REGION. FAIR WEATHER CONDITIONS
ARE EXPECTED TO PREVAIL DURING THE FIRST PART OF THIS WEEK...WITH
OVERNIGHT AND EARLY MORNING PASSING SHOWERS ACROSS EASTERN PR AND
THE USVI...FOLLOWED BY AFTERNOON CONVECTION ACROSS THE INTERIOR
AND WESTERN SECTIONS OF PR.

THE NEXT TROPICAL WAVE IS EXPECTED TO REACH THE LOCAL ISLANDS BY
TUESDAY NIGHT INTO WEDNESDAY. AS RESULT...THE POTENTIAL FOR
SHOWERS AND THUNDERSTORMS IS EXPECTED TO INCREASE DURING THAT
PERIOD. THEN...A WEAK SAHARAN AIR LAYER IS EXPECTED TO REACH THE
LOCAL AREA BY THURSDAY.

&&

.AVIATION...DRIER AIR OVER LEEWARD ISLANDS WILL SLOWLY PROGRESS TO
PUERTO RICO THRU 14/02Z. MEANWHILE UNSTABLE PROFILE IS PROMOTING
SHRA/TSRA ACROSS LOCAL CARIB WATERS AND PUERTO RICO BEHIND TROPICAL
WAVE. EXPECT AREAS OF MVFR/IFR AND MTN OBSCURATIONS MAINLY SOUTHERN
PR AND HIR TERRAIN. CONDS IMPRVG TIL 13/16Z THEN SHRA/TSRA DVLPG WRN
PR WITH MVFR CIGS/VIS AND MTN OBSCURATIONS. WINDS SFC TO FL150 ESE
10 TO 25 KT XCP LIGHTER AT SFC BFR 13/14Z AND GUSTS TO 30 KT NR TSRA.

&&

.MARINE...THE SHOWERS AND THUNDERSTORMS...NOW LOCATED OVER THE
CARIBBEAN WATERS AND MONA PASSAGE WILL GRADUALLY DIMINISH DURING
THE EARLY MORNING HOURS. AREAS OF HEAVY RAINFALL AND GUSTY
WINDS...WILL REMAIN POSSIBLE MAINLY OVER THE LOCAL CARIBBEAN
WATERS. SMALL CRAFT SHOULD EXERCISE CAUTION ACROSS MOST OF THE
LOCAL WATERS...AS SEAS ARE EXPECTED TO BE UP TO 6 FEET AND WINDS
UP TO 20 KNOTS. MARINE CONDITIONS WILL GRADUALLY IMPROVE
THROUGHOUT THE DAY. BETTER MARINE CONDITIONS ARE EXPECTED MONDAY
THROUGH TUESDAY

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 91 79 91 79 / 40 20 20 20
STT 91 82 90 79 / 40 20 20 20

[cycloneye]

A tropical wave accompanied by a broad low pressure system is
producing a large area of disturbed weather several hundred miles
southwest of the Cape Verde Islands. Environmental conditions are
expected to be conducive for development, and a tropical depression
could form during the next few days days while the system moves
west-northwestward to northwestward across the central tropical
Atlantic.
* Formation chance through 48 hours...medium...50 percent
* Formation chance through 5 days...high...80 percent

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
254 PM AST SUN SEP 13 2015

.SYNOPSIS...
TUTT LOW AND ASSOCIATED TROUGH OVER HISPANIOLA...WILL CONTINUE TO
SHIFT FARTHER WEST...WHILE WEAKENING AS A HIGH PRESSURE RIDGE
ALOFT BUILDS AND GRADUALLY SPREADS ACROSS THE REGION FROM THE
SUBTROPICAL ATLANTIC THROUGH THE MIDDLE OF THE UPCOMING WEEK.
SURFACE HIGH PRESSURE WILL BUILD ACROSS THE SOUTHWEST AND CENTRAL
ATLANTIC OVER THE NEXT SEVERAL DAYS. THIS WILL MAINTAIN MODERATE
EASTERLY TRADE WINDS ACROSS THE REGION. RECENT SATELLITE IMAGERY
AND DOPPLER WEATHER RADAR...SHOWED A DIMINISHING MOISTURE FIELD
AND SHOWER ACTIVITY ASSOCIATED WITH THE A DEPARTING TROPICAL WAVE...
EXITED THE THE FORECAST AREA...AND DRIER AIR FILTERED IN FROM THE
EAST.

&&

.DISCUSSION...A FEW AFTERNOON SHOWERS DEVELOPED AND AFFECTED
PORTIONS OF THE SAN JUAN METRO AREA...AS WELL AS SOME ISOLATED
AREAS IN THE NORTHWEST SECTIONS OF PUERTO RICO. HOWEVER...THE
SHOWER ACTIVITY WAS OF SHORT DURATION. MOSTLY CLOUDY SKIES DURING
THE MORNING HOURS BECAME VARIABLY CLOUDY AS MID TO HIGH LEVEL CLOUDINESS
CONTINUED TO DIMINISH ACROSS THE AREA DURING THE AFTERNOON HOURS.
SO FAR NO SIGNIFICANT RAINFALL ACCUMULATIONS WERE NOTED OR OBSERVED
ACROSS THE REGION AS DRIER AIR CONTINUE TO FILTER IN FROM THE
EAST...AND LAYERED PRECIPITABLE WATER CONTINUED TO DECREASE.
EXPECT SKIES TO BECOME PARTLY CLOUDY TO MOSTLY CLEAR DURING THE
OVERNIGHT HOURS.

LITTLE RAINFALL IS EXPECTED OVERNIGHT AND DURING THE MORNING HOURS
EXCEPT FOR A FEW PASSING SHOWERS ALONG PORTIONS OF THE EAST AND
SOUTHEAST COASTAL AREAS OF SOME OF THE ISLANDS. LATEST MODEL GUIDANCE
AS WELL AS SATELLITE IMAGERY INITIALIZED FAIRLY WELL...AND CONTINUED
TO SUGGEST IMPROVING WEATHER CONDITIONS OVER THE NEXT COUPLE OF
DAYS. AS PREVIOUSLY MENTIONED...A MUCH DRIER AIR MASS WILL SPREAD
ACROSS THE REGION. WITH THAT SAID...ON MONDAY AND TUESDAY...ONLY
ISOLATED TO OCCASIONALLY SCATTERED SHOWERS CAN BE EXPECTED MAINLY
DURING THE AFTERNOONS AND OVER PORTIONS OF CENTRAL AND WESTERN
PUERTO RICO. BY MID WEEK HOWEVER...THE CHANCE OF SHOWERS AND
THUNDERSTORMS RAINFALL WILL AGAIN INCREASE AS A TROPICAL WAVE IS
FORECAST TO REACH THE LOCAL AREA BRINGING ANOTHER SURGE OF TROPICAL
MOISTURE TO THE FORECAST AREA. STAY TUNED.

&&

.AVIATION...DRIER AIR OVER LEEWARD ISLANDS WILL CONTINUE TO
SPREAD ACROSS THE FLYING AREA SUPPORTING SCT OCNLY BKN CLD LYRS
THRU PRD. FEW CU/TCU WITH ISOLD -SHRA/SHRA OVR RGN BTW PR AND
LEEWARDS BUT MOSTLY VFR CONDS EN ROUTE. VFR CONDS AT ALL TAF SITE
TIL 14/12Z. WINDS E-SE BLO FL250 AT 10 TO 20 KT...BCMG MSTLY LGT/VRB
AT SFC FM 13/23Z-14/12Z THEN FM E 10-15 KTS AFT 13/14Z WITH OCNL
HIR GUSTS ALONG THE COASTAL TAF SITES.

&&

.MARINE...SMALL CRAFT SHOULD EXERCISE CAUTION MAINLY ACROSS THE
LOCAL OFFSHORE WATER AND LOCAL PASSAGES....AS SEAS WILL BE UP TO
6 FEET AND WINDS UP TO 20 KNOTS...DURING THE OVERNIGHT AND EARLY
MORNING HOURS. PLEASE REFER TO THE LATEST COASTAL WATERS FORECAST
ISSUED BY THE NATIONAL WEATHER SERVICE WFO SAN JUAN PR.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 91 79 90 / 20 20 20 20
STT 82 90 79 89 / 20 20 20 20

[cycloneye]

Showers and thunderstorms associated with a broad low pressure
system located several hundred miles west-southwest of the Cape
Verde Islands continue to show signs of organization. Environmental
conditions are expected to be conducive for development, and this
system is likely to become a tropical depression during the next day
or two while it moves generally northwestward across the central
tropical Atlantic.
* Formation chance through 48 hours...high...80 percent
* Formation chance through 5 days...high...90 percent

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
532 AM AST MON SEP 14 2015

.SYNOPSIS..HIGH PRESSURE RIDGE ALOFT BUILDS AND GRADUALLY SPREADS
ACROSS THE REGION FROM THE SUBTROPICAL ATLANTIC THROUGH THE MIDDLE
OF THE UPCOMING WEEK. SURFACE HIGH PRESSURE WILL BUILD ACROSS THE
SOUTHWEST AND CENTRAL ATLANTIC OVER THE NEXT SEVERAL DAYS. THIS
WILL MAINTAIN MODERATE EASTERLY TRADE WINDS ACROSS THE REGION.
TROPICAL WAVE WILL MOVE ACROSS THE REGION LATE TUESDAY INTO
WEDNESDAY.

&&

.DISCUSSION...PASSING SHOWERS WERE NOTED OVERNIGHT AND EARLY THIS
MORNING ACROSS THE COASTAL WATERS. SOME OF THESE SHOWERS AFFECTED
THE LOCAL ISLANDS. HOWEVER...RAINFALL ACCUMULATIONS WERE MINIMAL.
UPPER LEVEL RIDGE WILL BUILDS ACROSS THE REGION TODAY THROUGH AT
LEAST WEDNESDAY. THIS WILL PROMOTE STABLE ATMOSPHERIC CONDITIONS
ACROSS THE REGION. HOWEVER...ALTHOUGH A DRIER AIR MASS WILL
ENCOMPASS THE REGION LATER TODAY...LIMITED MOISTURE WILL COMBINE
WITH DAYTIME HEATING AND OROGRAPHICS EFFECTS TO PRODUCE SCATTERED
SHOWERS WITH ISOLATED THUNDERSTORMS OVER THE WESTERN INTERIOR
SECTION OF PUERTO RICO THIS AFTERNOON.

A TROPICAL WAVE LOCATED NEAR 50 WEST LONGITUDE THIS MORNING WILL
APPROACH THE LOCAL AREA TUESDAY NIGHT INTO WEDNESDAY. LATEST
SATELITE IMAGES SHOWS THIS WAVE HAVE A LARGE AREA OF MOISTURE
ASSOCIATED WITH IT. MOISTURE IS EXPECTED TO APPROACH THE LOCAL
AREA BY TUESDAY NIGHT...BUT BETTER MOISTURE IS EXPECTED FOR
WEDNESDAY MORNING AND WEDNESDAY AFTERNOON. AFTER THE PASSAGE OF
THIS WAVE...A RELATIVELY WET PATTERN IN EXPECTED TO PREVAIL ACROSS
THE AREA THROUGH THE END OF THE WEEK.

&&

.AVIATION...DRIER AIR WILL FILTER IN ACROSS THE REGION LATER
TODAY...SUPPORTING MOSTLY VFR CONDITIONS WITH ONLY VCSH. ISOLD
SHRA/TSRA MAY FORM OVER W PR BETWEEN 18/21...LEADING TO MVFR CIGS
POSSIBLE OVER TJMZ. EASTERLY WIND FLOW AROUND 20 KNOTS WILL PREVAIL
BELOW 20K FEET THROUGH THE FORECAST PERIOD.


&&

.MARINE...SEAS UP TO 5 FEET AND WINDS UP TO 20 KNOTS ARE EXPECTED
OVER THE COASTAL WATERS. SMALL CRAFT SHOULD EXERCISE CAUTION
ACROSS THE CARIBBEAN COASTAL WATERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 79 88 77 / 20 30 60 20
STT 91 80 88 78 / 20 40 60 40

[cycloneye]

A well-defined low pressure system located several hundred miles
west-southwest of the Cape Verde Islands is producing minimal shower
activity. However, environmental conditions are expected to be
conducive for development, and this system could still become a
tropical depression during the next day or two while it moves
generally northwestward across the central tropical Atlantic.
* Formation chance through 48 hours...high...80 percent
* Formation chance through 5 days...high...90 percent

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
309 PM AST MON SEP 14 2015

.SYNOPSIS...SURFACE HIGH PRESSURE ACROSS THE CENTRAL ATLANTIC WILL
PREVAIL FOR THE NEXT FEW DAYS...MAINTAINING A MODERATE EASTERLY
FLOW INTO WEDNESDAY...SHIFTING SLIGHTLY TO THE EAST IN THE LATTER
PART OF THE WEEK. HIGH PRESSURE IN THE UPPER LEVELS IS EXPECTED TO
GRADUALLY SPREAD ACROSS THE REGION FROM THE SUBTROPICAL ATLANTIC
THROUGH THE NEXT FEW DAYS. TROPICAL WAVE EXPECTED TO REACH THE
LOCAL AREA ON TUESDAY...INCREASING THE CHANCES OF SHOWERS AND
THUNDERSTORMS ACROSS THE AREA.

&&

.DISCUSSION...MOSTLY QUIET IN THE MORNING HOURS AS ONLY A FEW
SHOWERS WERE OBSERVED ACROSS THE LOCAL WATERS AND THE REST OF THE
AREA REMAINED WITH ONLY A FEW CLOUDS. EARLY IN THE AFTERNOON A FEW
SHOWERS STREAMED OFF THE USVI...SOME OF THEM AFFECTING CULEBRA AND
PORTIONS OF EASTERN PR. THERE WERE ALSO SOME LOCALLY INDUCED
SHOWERS ACROSS WESTERN PR. IT WAS RATHER WARM TODAY WITH MAX TEMPS
HOVERING AROUND 90 DEGREES ACROSS THE LOWER ELEVATIONS OF PR AND
ACROSS THE USVI.

APPROACHING TROPICAL WAVE WITH AXIS CURRENTLY AT AROUND 60W WILL
CAUSE A GRADUAL INCREASE IN THE LOCAL MOISTURE STARTING LATE
TONIGHT INTO TUESDAY MORNING. THIS WILL CAUSE AN INCREASE IN
PASSING SHOWER ACTIVITY EARLY IN THE MORNING HOURS OF TUESDAY.
LATEST GUIDANCE SUGGESTS THAT SHOWERS AND THUNDERSTORMS ARE
POSSIBLE ACROSS THE AREA ON TUESDAY. NO CHANGES WERE MADE TO THE
INHERITED FORECAST FOR TUESDAY AS THE LATEST GUIDANCE STILL
SUGGESTS A GOOD CHANCE OF SHOWERS. HOWEVER THERE IS SOME
DISCREPANCY ON THE AREAS WITH HIGHEST RAINFALL...THE WRF MODEL
LIKES WESTERN AND CENTRAL PR FOR THE MOST RAIN...WHILE THE HIGH
RESOLUTION NAM MODEL PREFERS THE WESTERN AND NORTHWESTERN SECTIONS
OF PR AS THE AREAS WITH THE HIGHEST AMOUNTS OF RAIN. SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS FOR THE LOCAL WATERS AND THE
USVI UNDER MOSTLY CLOUDY SKIES.

SOME SAHARAN DUST IS EXPECTED TO MOVE INTO THE AREA ON
WEDNESDAY ACCORDING TO GUIDANCE...SO THERE MAY BE LIMITED SHOWER
ACTIVITY ON WEDNESDAY EVEN THOUGH WE STILL HAVE SOME GOOD
LINGERING MOISTURE ACROSS THE AREA.

FOR THE REST OF THE WEEK...SOME PATCHES OF MOISTURE ARE STILL
EXPECTED TO BE PRESENT...WHICH COULD HELP IN THE DEVELOPMENT OF
LOCALLY INDUCED SHOWERS AND THUNDERSTORMS IN THE AFTERNOONS.

&&

.AVIATION...PREVAILING VFR CONDS EXPECTED THROUGH THE LOCAL
TERMINALS. TEMPO MVFR POSSIBLE FOR TJMZ AS AFTERNOON CONVECTION
DEVELOPS SHRA/TSRA OVER THE AREA. APPROACHING TROPICAL WAVE WILL
GRADUALLY BRING MORE CLOUDINESS AND SHRA ACTIVITY TO THE LOCAL
AREA AFTER 15/06Z. WINDS WILL CONTINUE FROM THE EAST WITH SEA
BREEZE VARIATIONS AT AROUND 10-15KT AND GUSTY THROUGH 14/23Z THEN
DECREASING SLIGHTLY OVERNIGHT.

&&

.MARINE...SEAS WILL CONTINUE AT 2-4 FT IN THE NEARSHORE WATERS
WITH 3-5 FT IN THE OFFSHORE WATERS. WINDS WILL BE MAINLY BETWEEN
10-20 KNOTS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 88 77 92 / 30 60 20 40
STT 80 88 78 86 / 40 60 40 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
520 AM AST TUE SEP 15 2015

.SYNOPSIS...TROPICAL WAVE OVER THE EASTERN CARIBBEAN WILL
CONTINUE TO MOVE WEST AND WILL APPROACH THE REGION LATE THIS
MORNING. THIS WAVE AND THE MOISTURE ASSOCIATED WITH IT...WILL
AFFECT THE LOCAL REGION THROUGH TOMORROW AFTERNOON.

&&

.DISCUSSION...APPROACHING TROPICAL WAVE WITH AXIS CURRENTLY AT
AROUND 63W WILL CAUSE A GRADUAL INCREASE IN THE LOCAL MOISTURE
STARTING THIS MORNING AND CONTINUING THROUGH AT LEAST WEDNESDAY
AFTERNOON. THIS WILL CAUSE AN INCREASE IN PASSING SHOWER ACTIVITY
EARLY IN THE MORNING HOURS TODAY. LATER TODAY...SHOWERS WITH
THUNDERSTORMS ARE EXPECTED TO SPREAD ACROSS THE REGION. NUMEROUS
SHOWERS WERE SEEN ACROSS THE COASTAL COASTAL WATERS MOVING SLOWLY
NORTHWEST. LATEST SJU-GFS GUIDANCE INDICATED PWAT VALUES WILL BE
AROUND 2.25 INCHES TODAY AND TOMOROW...DIMINISHING BELOW 2.0
INCHES BY TOMORROW NIGHT. THEREFORE...EXISTS A HIGH CHANCE FOR
SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE REGION NEXT 36 HOURS.

WEATHER CONDITIONS ARE EXPECTED TO IMPROVE LATE WEDNESDAY AFTER
THE PASSAGE OF THIS WAVE. AFTER THE PASSAGE OF THIS WAVE...NO
SIGNIFICANT WEATHER EVENTS ARE EXPECTED TO AFFECT THE
REGION FOR NOW. THE SHOWER ACTIVITY WILL BE CONCENTRATED OVER THE
WESTERN INTERIOR PUERTO RICO EACH AFTERNOON...WITH SOME PASSING
SHOWERS AFFECTING THE U.S. VIRGIN ISLANDS AND EASTERN PUERTO RICO
DURING THE MORNING HOURS.

&&

.AVIATION...SHRA/TSRA WILL INCREASE DURING THE DAY AS TROPICAL WAVE
MOVES OVER THE FLYING AREA LATER TODAY. CLOUDINESS AND SHOWERS WILL
SPREAD OVER THE LEEWARD AND USVI TERMINALS THIS MORNING AND OVER PR
LATER THIS MORNING AND AFTERNOON. MVFR CONDS POSSIBLE IN SHRA/TSRA
THRU TONIGHT. LOW LVL ENE WINDS OF 15-25 KT...VEERING FM THE ESE
THIS AFTERNOON.

&&

.MARINE...SEAS UP TO 5 FEET AND WINDS UP TO 20 KNOTS ARE EXPECTED
TO PREVAIL ACROSS THE COASTAL WATERS. SMALL CRAFT SHOULD EXERCISE
CAUTION.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 90 78 / 60 50 50 30
STT 89 80 87 79 / 60 60 60 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
219 PM AST TUE SEP 15 2015

.SYNOPSIS...TROPICAL WAVE WITH AXIS NEAR 64W IS BRINGING SHOWERS
AND THUNDERSTORMS TO THE LOCAL AREA ALONG WITH CLOUDY SKIES. THIS
TROPICAL WAVE IS EXPECTED TO CONTINUE AFFECTING THE LOCAL AREA
THROUGH TONIGHT. SAHARAN DUST IS EXPECTED TO MOVE INTO THE LOCAL
AREA ON WEDNESDAY INTO EARLY THURSDAY...WHICH COULD INHIBIT
AFTERNOON CONVECTION OVER PUERTO RICO WHILE KEEPING THE LOCAL AREA
WITH ISOLATED TO SCATTERED SHOWERS. SURFACE HIGH PRESSURE ACROSS
THE CENTRAL ATLANTIC WILL KEEP A MODERATE EASTERLY WIND FLOW FOR
THE NEXT FEW DAYS. THERE IS ALSO A SURFACE HIGH PRESSURE ACROSS
THE WESTERN ATLANTIC WHICH WILL ALSO PROMOTE EASTERLY WINDS
THROUGH THE END OF THE WEEK.

&&

.DISCUSSION...THE SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE
TROPICAL WAVE ARE GRADUALLY INCREASING...BECOMING MORE NUMEROUS AS
THE AFTERNOON PROGRESSES. RADAR ESTIMATES INDICATE THAT SOME OF
THESE SHOWERS ARE LEAVING A QUARTER TO A HALF AN INCH OF RAIN IN
THE AREAS WITH THE MOST RAINFALL. AT THIS TIME WE EXPECT THE
SHOWERS TO CONTINUE THROUGH THE AFTERNOON AND POSSIBLY INTO LATE
TONIGHT AS THERE IS SOME GOOD CONVECTION BEHIND THE AXIS OF THE
TROPICAL WAVE. THE SATELLITE DERIVED PRECIPITABLE WATER IMAGERY
INDICATES THAT THE PRECIPITABLE WATER VALUES ARE CLOSE TO 2.2
INCHES WHICH IS ABOVE NORMAL FOR THIS TIME OF YEAR. THIS MOISTURE
IS EXPECTED TO LINGER THROUGH WEDNESDAY...HOWEVER SAHARAN DUST IS
MOVING IN FOR WEDNESDAY...WHICH MAY INHIBIT THE SHOWER AND
THUNDERSTORM DEVELOPMENT OVER THE LOCAL AREA. HAVING SAID
THAT...THERE IS STILL ENOUGH MOISTURE THAT WE CANNOT RULE OUT SOME
SHOWERS AND THUNDERSTORMS TO DEVELOP WHEN COMBINED WITH THE LOCAL
EFFECTS.

THURSDAY AND THROUGH THE WEEKEND LOOKS RATHER TYPICAL FOR THIS
TIME OF YEAR WITH NORMAL MOISTURE AND LOCALLY INDUCED SHOWERS AND
THUNDERSTORMS ACROSS THE INTERIOR AND WESTERN PORTIONS OF PR IN
THE AFTERNOONS AND PASSING SHOWERS IN THE NIGHT AND EARLY MORNING
HOURS FOR PR AND THE USVI.


&&

.AVIATION...TROPICAL WAVE WILL BRING SCT TO NUMEROUS SHRA/TSRA TO
THE LOCAL TERMINALS. MVFR AND POSSIBLE IFR CONDS FOR TJMZ FROM
15/18Z TO 15/20Z. VCSH/VCTS ACROSS MOST OF THE LOCAL TERMINALS
WITH TEMPO SHRA/TSRA LIKELY THROUGH 16/06Z OR SO AS THE TROPICAL
WAVE CONTINUES TO MOVE WEST. BKN-OVC SKIES EXPECTED AT FL060 TO
FL070...LOWER CIGS WITH THE SHRA/TSRA. EAST TO ESE WINDS AT ABOUT
15KT AND GUSTY...POSSIBLE GUSTS TO AROUND 25KT NEAR THE SHRA/TSRA.
WX CONDS TO IMPROVE EARLY WEDNESDAY MORNING.


&&

.MARINE...SEAS WILL CONTINUE TO BE AT 3 TO 5 FEET ACROSS THE
OFFSHORE WATERS WHILE THE NEARSHORE WILL BE 2 TO 4. WINDS WILL BE
GENERALLY 10 TO 20 KNOTS WITH HIGHER WINDS AND SEAS NEAR THE
SHOWERS AND THUNDERSTORMS. SMALL CRAFT SHOULD EXERCISE CAUTION.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 90 78 89 / 50 50 30 30
STT 80 87 79 89 / 60 60 30 30

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
547 AM AST WED SEP 16 2015

.SYNOPSIS...UPPER TROUGH/TUTT BETWEEN CUBA AND HISPANOLA WILL
SLOWLY MOVE EASTWARD OVER THE NEXT FEW DAYS...RELOCATING EAST OF
THE AREA DURING THE WEEKEND. TROPICAL WAVE OVER THE MONA PASSAGE
WILL CONTINUE TO INDUCE SHOWER AND THUNDERSTORM ACTIVITY ACROSS
THE REGION TODAY. WEATHER CONDITIONS WILL IMPROVE SOMEWHAT THIS
EVENING AS DEEP MOISTURE GRADUALLY MOVES AWAY FROM THE AREA. A
PULSE OF SAHARAN DUST WILL SPREAD OVER THE REGION LATER TODAY AND
PERSIST ON THURSDAY.

&&

.DISCUSSION...UNSETTLED CONDITIONS HAVE PREVAILED ACROSS THE
REGION DURING THE OVERNIGHT HOURS. SHOWERS AND THUNDERSTORMS WERE
OBSERVED ACROSS MOST OF THE WATERS AS WELL AS PORTIONS OF THE U.S.
VIRGIN ISLANDS...VIEQUES...CULEBRA AND EASTERN PUERTO RICO. SINCE
MIDNIGHT...RAINFALL ACCUMULATIONS HAVE RANGED BETWEEN ONE QUARTER
AND HALF-INCH ACROSS THESE AREAS...AND UP TO ONE INCH IN THE BORDER
BETWEEN NAGUABO AND LAS PIEDRAS. NEW SHOWERS AND THUNDERSTORMS
COULD DEVELOP DURING THE DAY AS CONVECTIVE INSTABILITY AND DEEP
MOISTURE REMAIN HIGH ACROSS THE REGION THROUGH THIS AFTERNOON.
THE HEAVIEST RAINFALL TODAY IS EXPECTED OVER THE NORTH AND WEST
PORTIONS OF PUERTO RICO DURING THE AFTERNOON HOURS...BUT SCATTERED
SHOWERS WITH MODERATE RAINFALL CAN DEVELOP ANYWHERE IN THE
FORECAST AREA DUE TO THE UNSTABLE AND MOIST CONDITIONS.

WEATHER CONDITIONS WILL IMPROVE SLOWLY TONIGHT INTO THURSDAY AS
TROPICAL WAVE AND ITS ASSOCIATED MOISTURE MOVES OVER HISPANOLA.
MOISTURE LEVELS WILL RETURN TO NORMAL ON THURSDAY. A PULSE OF
SAHARAN DUST WILL REACH THE FORECAST AREA LATER TODAY...LINGERING
THROUGH THURSDAY. AS A RESULT...DRIER AND MORE STABLE CONDITIONS
WILL PREVAIL ON THURSDAY. ALTHOUGH...NO SIGNIFICANT WEATHER
FEATURE IS EXPECTED TO AFFECT THE LOCAL ISLANDS FOR THE NEXT
SEVERAL DAYS... TYPICAL AFTERNOON CONVECTION CANNOT RULE OUT DUE
TO THE LOCAL EFFECTS AND THE PROXIMITY OF THE AFOREMENTIONED UPPER
TROUGH/TUTT.

&&

.AVIATION...BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE OVER
TIST AND TISX THROUGH AT LEAST 16/16Z. BRIEF PERIODS OF MVFR
CONDITIONS WITH MOUNTAIN OBSCURATIONS CAN BE EXPECTED AT
TJMZ...AND TJBQ FROM 16/16Z THROUGH 16/22Z IN SHRA/TSRA. LOW LEVEL
WINDS WILL BE MAINLY FROM THE SOUTHEAST AT 10 TO 15 KTS.

&&

.MARINE...SEAS OF 2-4 FEET CAN BE EXPECTED ACROSS THE NEARSHORE
WATERS. SLIGHTLY HIGHER SEAS UP TO 5 FEET ARE POSSIBLE ACROSS THE
OFFSHORE WATERS. NO MUCH CHANGE ARE ANTICIPATED OVER THE NEXT FEW
DAYS AS MODERATE TRADE WINDS WILL PREVAIL OVER THE REGION. FOR
TODAY...THE MAIN HAZARD FOR MARINERS WILL BE THE THUNDERSTORMS
WHERE LOCALLY HIGHER SEAS AND GUSTY WINDS ARE POSSIBLE AT TIMES.
THEREFORE...SMALL CRAFT OPERATORS SHOULD EXERCISE CAUTION.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 80 89 79 / 50 20 20 20
STT 89 79 89 77 / 60 20 20 20