Caribbean - Central America Weather

[Macrocane]

Thanks everyone! and fortunately nothing bad happened. Some impressive videos:

[youtube]http://www.youtube.com/watch?v=LYLaOlQgYj4[/youtube]

[youtube]http://www.youtube.com/watch?v=2LdbnSERo_0[/youtube]

And my favorite. This was shot from San Salvador volcano:

[youtube]http://www.youtube.com/watch?v=zzP4nT9Oljc[/youtube]

[cycloneye]

Thanks everyone! and fortunately nothing bad happened. Some impressive videos:

http://www.youtube.com/watch?v=LYLaOlQgYj4

http://www.youtube.com/watch?v=2LdbnSERo_0

And my favorite. This was shot from San Salvador volcano:

http://www.youtube.com/watch?v=zzP4nT9Oljc

Very impressive videos.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
338 PM AST THU AUG 22 2013

.SYNOPSIS...TUTT LOW WILL MEANDER OVER PUERTO RICO UNTIL FRIDAY
MORNING. THEN...THE TUTT WILL MOVE WESTWARD INTO THE DOMINICAN
REPUBLIC BY SATURDAY. AN UPPER LEVEL RIDGE WILL BUILD OVER THE
EASTERN CARIBBEAN EARLY NEXT WEEK. AT LOW LEVELS...AN INDUCED
TROUGH/EASTERLY PERTURBATION OVER THE FORECAST AREA WILL CONTINUE
TO MOVE AWAY FROM THE LOCAL REGION TONIGHT. A DRYING TREND IS
FORECAST FOR LATE FRIDAY THROUGH THE WEEKEND AS A DRY AND STABLE
AIRMASS ENCOMPASS THE LOCAL REGION.

&&

.DISCUSSION...SATELLITE IMAGERY AS WELL AS RADAR DATA SHOWED SHOWERS
AND THUNDERSTORMS AFFECTING PORTIONS OF PUERTO RICO AND U.S VIRGIN
ISLANDS TODAY. A FEW STRONG THUNDERSTORMS DEVELOPED ACROSS PORTIONS
OF THE SOUTHEAST...EASTERN INTERIOR...NORTH CENTRAL AND THE SAN JUAN
METRO AREA THIS AFTERNOON...PRODUCING VERY HEAVY RAINFALL...STRONG
GUSTY WINDS AND DANGEROUS LIGHTNING AS THEY PASSED ACROSS THOSE
AREAS. RAINFALL ACCUMULATIONS GENERALLY RANGED BETWEEN ONE TO
THREE INCHES. HIGH MOISTURE ADVECTION ASSOCIATED WITH AN INDUCE
TROUGH...GOOD LOW LEVEL CONVERGENCE AND A TUTT LOW ALOFT COMBINED
TO PRODUCE ACTIVE WEATHER ACROSS THE ISLANDS TODAY. MOST OF THE
ACTIVITY IS EXPECTED TO DIMINISH THIS EVENING... GIVING THE WAY TO
PARTLY CLOUDY SKIES AND ISOLATED TO SCATTERED SHOWERS ACROSS THE
LOCAL WATERS TONIGHT.

MODELS SUGGEST THAT THE INDUCED TROUGH AND THE TUTT LOW WILL MOVE
AWAY FROM THE LOCAL AREA TONIGHT AND FRIDAY. AS THESE FEATURES
PULL AWAY...MOISTURE WILL DECREASE GRADUALLY DURING THE NEXT 24
HOURS...REACHING THE MINIMA ON SATURDAY WHEN A DRIER AIRMASS WITH
SAHARAN DUST ENCOMPASS THE AREA FROM THE EAST. THIS WILL TO RESULT
IN A MINIMA IN PRECIPITATION DURING THE WEEKEND. ALTHOUGH...WE ARE
LOOKING FOR IMPROVING CONDITIONS DURING THE UPCOMING WEEKEND...THOUGH
SHALL NOT RULE OUT THE POSSIBILITY OF ISOLATED CONVECTION OVER
WESTERN PUERTO RICO IN THE AFTERNOON.

&&

.AVIATION...MVFR CONDITIONS AT JSJ THROUGH 21Z...THEN CONDITIONS
IMPROVING TO VFR THIS EVENING EVERYWHERE WITH CLOUDS GRADUALLY
DISSIPATING. VFR EVERYWHERE TOMORROW WITH SOME DUST HAZE.

&&

.MARINE...SEAS 2-4 FT NEARSHORE AND 3-5 FT OFFSHORE. TSTMS OVER
ATLANTIC COASTAL WATERS WILL BE THE MAIN THREATS THROUGH THIS EVENING.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 80 90 / 40 40 20 20
STT 79 89 81 92 / 50 50 30 30

[msbee]

Thanks everyone! and fortunately nothing bad happened. Some impressive videos:

[youtube]http://www.youtube.com/watch?v=LYLaOlQgYj4[/youtube]

[youtube]http://www.youtube.com/watch?v=2LdbnSERo_0[/youtube]

And my favorite. This was shot from San Salvador volcano:

[youtube]http://www.youtube.com/watch?v=zzP4nT9Oljc[/youtube]

Wow! incredible videos!

[cycloneye]

Good morning. A mainly good weather pattern will prevail this weekend in PR with some hazy conditions.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
444 AM AST FRI AUG 23 2013

.SYNOPSIS...TUTT LOW CENTERED OVER PUERTO RICO THIS MORNING WILL
CONTINUE TO PROPAGATE WESTWARD TODAY THROUGH THE WEEKEND WHILE
FILLING. MEANWHILE...ATLANTIC HIGH PRESSURE ALOFT WILL BUILD ACROSS
THE NORTHEASTERN CARIBBEAN. THE PRESENT SCENARIO ALOFT IS MAINTAINING
A WEAK DIFFLUENT FLOW JUST SOUTH OF THE ISLANDS...AND THIS WAS HELPING
TO ENHANCE SOME CONVECTION OVER THE SOUTHERN CARIBBEAN WATERS. THE
CURRENT UPPER LEVEL WIND FLOW CONTINUE TO SPREAD MID TO UPPER LEVEL
CLOUD DEBRIS NORTHWARDS ACROSS THE REGION. IN THE LOW LEVELS...
STRONG ATLANTIC HIGH PRESSURE CONTINUED TO SINKS FURTHER SOUTH
ACROSS THE REGION TO MAINTAIN MODERATE EASTERLY TRADE WINDS.
SATELLITE IMAGERY SHOWED A DRIER AIR MASS FILTERING IN FROM THE
EAST ACCOMPANYING THE SAHARAN AIR LAYER. A LOW AMPLITUDE TROPICAL
WAVE WAS LOCATED NEAR 53 WEST THIS MORNING IS FORECAST TO CROSS
INTO THE EASTERN CARIBBEAN OVER THE WEEKEND. SO FAR IT IS EXPECTED
TO MOVE SOUTH OF THE REGION.

&&

.DISCUSSION...LATEST GFS MODEL GUIDANCE INITIALIZED WELL AND
CONTINUED TO SUGGEST THAT HIGH PRESSURE RIDGE WILL BUILD ACROSS
THE NORTHEAST CARIBBEAN DURING THE NEXT FEW DAYS. IN DOING SO...
EXPECT THE TRADE WIND CAP INVERSION TO GRADUALLY STRENGTHEN ACROSS
THE REGION AND HELP SUPPRESS CONVECTIVE DEVELOPMENT OVER THE UPCOMING
WEEKEND. MODEL GUIDANCE ALSO CONTINUED TO FORECAST A RAPID DECREASE
IN PRECIPITABLE WATER OVER THE NEXT FEW DAYS AS THE SAHARAN AIR LAYER
IS EXPECTED TO SPREAD WESTWARDS ACROSS REGION.

IN THE MEANTIME...THE AVAILABLE MOISTURE AND THE PROXIMITY OF THE UPPER
LOW SHOULD BE ENOUGH TO COMBINE WITH LOCAL AND DIURNAL EFFECTS TODAY.
THIS WILL LEAD TO SOME ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT
OVER PARTS OF THE ISLANDS. EXPECT SOME EARLY MORNING SHOWERS TO REACH
PARTS OF THE VIRGIN ISLANDS AND THE EAST SECTIONS OF PUERTO RICO...BUT
THE MAIN FOCUS OF THE AFTERNOON SHOWERS AND ISOLATED THUNDERSTORM
WILL BE ACROSS THE NORTH CENTRAL AND WEST SECTIONS OF PUERTO RICO
BASED ON THE PRESENT STEERING FLOW. ISOLATED AFTERNOON THUNDERSTORMS
WILL ALSO REMAIN POSSIBLE OVER PARTS OF BUT SO FAR NO WIDESPREAD
RAINFALL IS EXPECTED TODAY.

&&

.AVIATION...BETWEEN 23/10Z TO 23/16Z SHRA/TSRA WILL MOVE OVER THE
EASTERN SECTIONS OF PUERTO RICO AS WELL AS ACROSS THE USVI...
PRODUCING BRIEF PERIODS OF MVFR CONDITIONS ACROSS TJSJ AND ACROSS
THE FLYING TERMINALS OF THE U.S. VIRGIN ISLANDS. AFTER 23/18Z
SHRA/TSRA WILL DEVELOP ACROSS CENTRAL AND WESTERN INTERIOR PUERTO
RICO...INDUCING PERIODS OF MVFR CONDITIONS ACROSS TJMZ AND TJBQ.
MOSTLY VFR CONDITIONS EXPECTED ACROSS THE LOCAL FLYING AREA AFTER
23/22Z. WINDS WILL CONTINUE MAINLY FROM THE EAST UP TO 20 KNOTS...
ALL THE WAY FROM THE SURFACE TO 15K FEET.

&&

.MARINE...MARINE CONDITIONS CONTINUE RELATIVELY TRANQUIL.HOWEVER THE
POSSIBILITY OF ISOLATED THUNDERSTORMS WILL CONTINUE TODAY ACROSS PARTS
OF THE COASTAL WATERS. SMALL CRAFT OPERATORS SHOULD EXERCISE CAUTION
TODAY DUE TO MODERATE TO LOCALLY FRESH TRADE WINDS...AND ALSO
BRIEF GUSTY WINDS ACCOMPANYING THE ISOLATED THUNDERSTORMS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 91 79 / 40 20 20 20
STT 90 80 90 81 / 50 30 30 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
234 PM AST FRI AUG 23 2013

.SYNOPSIS...UPPER LOW OVER THE MONA CHANNEL WILL RETROGRESS TOWARD
HISPANIOLA OVER THE WEEKEND. SUBTROPICAL RIDGE WILL BUILD OVER
THE NORTHEAST CARIBBEAN SAT AND HOLD THROUGH MUCH OF NEXT WEEK.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS OVR PR WILL DISSIPATE BY
THIS EVENING WITH MUCH DRIER AND STABLE AIR MASS (SAL) MOVING IN
FOR THE WEEKEND. NEXT TROPICAL WAVE IS FCST TO MOVE ACROSS THE
AREA MON AFTERNOON AND TUE AND WILL BRING EXTENSIVE CLOUDS WITH
NUMEROUS SHOWERS AND THUNDERSTORMS. HOWEVER...THE BEST MOISTURE
WILL STAY SOUTH OVR THE CARIBBEAN SEA. SO DON`T THINK THIS WAVE
POSES ANY SERIOUS THREAT OF FLOODING.

CONDITIONS IMPROVE SOMEWHAT MIDDLE OF NEXT WEEK BUT STILL WITH
TYPICAL AFTERNOON CONVECTION OVER WESTERN PR.


&&

.AVIATION...SHRA/TSRA OVR PR HAVE GENERATED MVFR/IFR CONDS WITH MTN
OBSCURATIONS AND WILL IMPROVE AFT 23/22Z. EXPECT VFR CONDS PR AFT
24/02Z. A BAND OF MOISTURE MOVING IN FROM THE SE WILL BRING BRIEF
MVFR IN SCT LOCATIONS IN THE LEEWARD AND U.S. VIRGIN ISLANDS BEGG
24/02Z AT TKPK...TNCM AND 24/06-08Z AT TISX...TIST. CONDS IMPROVING
AFT 24/12Z. LLVL WINDS E 10-20 KTS INCRG AFT 24/06Z TO 15-25 KTS
JUST ABV THE SFC TO 15 KFT.


&&

.MARINE...SEAS 3-5 FT AND WINDS UP TO 20 KT. SCT TSRA OVER MONA
CHANNEL THE MAIN THREAT THROUGH THIS EVENING. TROPICAL WAVE TO
MOVE ACROSS THE AREA MON AFTERNOON-MON NIGHT WITH AN INCREASE IN SHOWERS.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 91 79 90 / 10 10 10 10
STT 80 90 81 90 / 10 10 10 10

[cycloneye]

Good morning. Good weather is expected today in PR with only a few afternoon showers in the interior with some haze.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
447 AM AST SAT AUG 24 2013

.SYNOPSIS...AT UPPER LEVELS...LOW PRESSURE OVER THE DOMINICAN
REPUBLIC WILL CONTINUE TO MOVE TO THE WEST NORTHWEST AS HIGH
PRESSURE NOSES IN FROM THE EAST AND COVERS THE FORECAST AREA BY
TUESDAY. HIGH PRESSURE CONTINUES TO BE THE DOMINANT INFLUENCE INTO
THE FOLLOWING WEEK.

AT MID AND LOWER LEVELS...HIGH PRESSURE EXTENDS SOUTHWEST FROM THE
NORTHEAST AND CENTRAL ATLANTIC TO OVER THE WATERS JUST NORTH OF
THE AREA. A TROPICAL WAVE WILL MOVE THROUGH THE AREA MONDAY
AFTERNOON AND MONDAY NIGHT WITH WEAK RIPPLES AND MOISTURE
FOLLOWING THROUGH THE REST OF THE WEEK.

&&

.DISCUSSION...A FEW SLIGHT SHOWERS CONTINUED OVER THE LOCAL
WATERS AND ONE MOVED ACROSS THE SAN JUAN AIRPORT LEAVING 0.04 OF
AN INCH OF RAIN. OTHERWISE IT WAS DRY WITH PARTLY CLOUDY SKIES.
THE 24/00Z SOUNDING SHOWED DRYING MID LAYERS WITH SOME INCREASE IN
THE TRADE WINDS BETWEEN 1 AND 15 KFT. THIS WILL LIMIT THE SHOWER
ACTIVITY OVER THE AREA BUT EXPECT SOME STRONG THUNDERSTORMS TO
FORM DUE TO BETTER HEATING UNDER CLEARER SKIES. THE GFS FORECAST
INDICATED ISOLATED SHOWERS...BUT THE NAM SHOWED A GOOD CHANCE OF
SHOWERS OVER A LINE FROM THE LUQUILLO RANGE TO HORMIGUEROS...AND
SO TOOK A MID WAY POSITION BETWEEN THE TWO FORECAST MODELS AND
SPECIFIED SCATTERED THUNDERSTORMS...MAINLY SOUTHWEST INTERIOR OF
PUERTO RICO. THE GFS FORECAST SOUNDING STILL SHOWED DECENT CAPE OF
3370 J/KG AND A MINUS 5.6 LIFTED INDEX EVEN IF FORECAST
PRECIPITABLE WATER IS HIGHER THAN MINUS 6. UPPER LEVEL WINDS ARE
SOUTHERLY ABOVE 20 KFT. THE 23/18Z RUN OF THE GFS HAD GOOD
DIVERGENCE OVER WESTERN PR FROM 24/18-25/00Z...BUT THIS IS DELAYED
IN THE LATEST RUN TO THE OVERNIGHT PERIOD...WHICH MAY THEN HAVE
LITTLE EFFECT. IF THIS DIVERGENCE RE-DEVELOPS...AND THAT IS NOT
EXPECTED...SHOWERS AND THUNDERSTORMS WOULD BE STRONGER AND SOME
LOCAL URBAN AND SMALL STREAM FLOODING COULD OCCUR. MORE MOISTURE
MOVES INTO THE AREA ON MONDAY AND AREAS OF MOISTURE CONTINUE
THROUGH SATURDAY...ALTHOUGH THE BEST DYNAMICS SHOULD BE WITH THE
TROPICAL WAVE THAT MOVES THROUGH ON MONDAY AFTERNOON AND EVENING.

&&

.AVIATION...
VFR CONDS EXPCTD AT ALL TAF SITES OVERNIGHT. LATE MORNING
EARLY AFTERNOON SHRA IN AND AROUND TIST AND TISX AND AROUND TJMZ
AFTER 24/18Z...WITH POSSIBLE BRIEF PDS OF MVFR CONDS. SFC WINDS
GENERALLY FROM EAST AT 5-15 KTS.

&&

.MARINE...WINDS WILL CAUSE SEAS TO RISE EARLY NEXT WEEK TO 6 FEET
IN SOME OUTER WATERS AND WINDIER LOCATIONS...OTHERWISE MARINE
CONDITIONS WILL CHANGE LITTLE. A TROPICAL WAVE WILL BRING
INCREASED ACTIVITY TO THE LOCAL WATERS MONDAY AND MONDAY NIGHT.
MOISTURE WILL KEEP SHOWERS ACTIVE THROUGH MUCH OF THE REST OF
THE WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 79 91 79 / 20 10 10 20
STT 90 80 90 81 / 30 10 10 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
334 PM AST SAT AUG 24 2013

.SYNOPSIS...SUBTROPICAL RIDGE WILL REMAIN THE DOMINANT WX FEATURE
THROUGH MOST OF NEXT WEEK. SVRL TROPICAL WAVES WILL MOVE ACROSS
THE CARIBBEAN OVR THE NEXT SEVEN DAYS WITH THE MOST SIGNIFICANT
MONDAY.

&&

.DISCUSSION...A WEAK TROPICAL WAVE OVR THE SOUTHEAST CARIBBEAN
WILL CONTINUE TO MOVE THROUGH THE ERN CARIBBEAN SEA TONIGHT
THROUGH SUN BUT STAY MAINLY SOUTH OF THE FCST AREA. ONLY A SLIGHT
INCREASE IN MOISTURE IS EXPECTED WITH THIS WAVE SUN.

A SECOND TROPICAL WAVE ALONG 43W WILL MOVE ACROSS THE AREA MONDAY.
THIS WAVE SHOWS UP AS A SWIRL OF LOW CLOUDS WITH NO DEEP
CONVECTION ATTM ON VISIBLE IMAGERY AND IS NOT BEING ANALYZED OR
MENTIONED ON THE TAFB TROP WX DCSN (TWDAT). MODELS ARE SHOWING
SOME TIMING DIFFERENCES WITH THE ARRIVAL OF THIS WAVE OVER PR
WITH THE ECMWF BEING ABOUT 12 HRS FASTER (12Z MON) THAN THE SLOWER
GFS/GFES (00Z TUE). GFS IS MORE AGGRESSIVE THAN ECMWF WITH
RAINFALL POTENTIAL WITH THIS WAVE. NEED TO CLOSELY MONITOR THIS
WAVE AS IT IS ACCOMPANIED BY SIG AMOUNTS OF 850 MB VORTICITY AS
SEEN ON GFS FIELDS AND SATELLITE IMAGERY FOR FLOODING POTENTIAL
MONDAY. A DRYING TREND IS EXPECTED TO COMMENCE TUE BEHIND THIS
WAVE. NON-EVENTFUL WED-THU IN BETWEEN WAVES.

A THIRD TROPICAL WAVE IS ALONG 30W AND IS MUCH BETTER DEFINED ON
TPW AND LPW IMAGERY. THIS WAVE IS EXPECTED TO REACH THE AREA NEXT FRI.

A FOURTH TROPICAL WAVE IS CURRENTLY OVER WRN AFRICA AND IS
ASSOCIATED WITH AN MCS. GLOBAL MODELS HAVE BEEN VERY CONSISTENT
IN DEVELOPING THIS WAVE EVENTUALLY INTO A TROPICAL CYCLONE IN THE
DY5-7 TIME FRAME (THU AUG 29-SAT AUG 31) ALTHOUGH THEY ARE SHOWING
SIGNIFICANT SPEED DIFFERENCES. BASED ON OFFICIAL NHC/WPC MEDIUM
RANGE GUIDANCE THIS WAVE MAY HAVE A LOW PRES AREA ASSOCIATED WITH
IT OR MAY BECOME A TROPICAL CYCLONE NEXT FRI AND BE IN THE
VICINITY OF 14N AND 47W NEXT SAT AUG 31.

&&

.AVIATION...VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS ACROSS THE
LOCAL TERMINALS. INCREASE IN CLOUDINESS ACROSS THE EASTERN INTERIOR
AND THE SOUTHERN SLOPES OF PR THIS AFTERNOON MAY TURN INTO ISOLD
SHRA/TSRA ACTIVITY...CAUSING VCSH/VCTS FOR TJPS AND TJMZ. CONDITIONS
EXPECTED TO IMPROVE BY 24/23Z. WINDS EXPECTED FROM THE EAST WITH SEA
BREEZE VARIATIONS THROUGH THE AFTERNOON AT 10 TO 15 KNOTS AND GUSTY.
SURFACE WINDS TO REMAIN FROM THE EAST OVERNIGHT WITH ONLY ISOLD
PASSING SHRA EXPECTED ACROSS THE LOCAL AREA.

&&

.MARINE...A TRADE WIND SURGE WILL MOVE ACROSS THE AREA TONIGHT
WITH INCREASING WINDS UP TO 20 KNOTS. NMRS SHOWERS AND SCT
THUNDERSTORMS EXPECTED MON-MON NIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 90 78 89 / 10 10 20 60
STT 80 90 80 90 / 10 10 40 60

[cycloneye]

Good morning. Scattered showers will move thru PR today thru Monday as a Tropical Wave moves by.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
518 AM AST SUN AUG 25 2013

.SYNOPSIS...AT UPPER LEVELS...HIGH PRESSURE IS MOVING INTO THE
LOCAL AREA AND WILL DOMINATE THE WEATHER PATTERN THROUGH AT LEAST
NEXT WEEKEND.

AT MID LEVELS...HIGH PRESSURE REMAINS ENTRENCHED IN THE CENTRAL
ATLANTIC WITH A RIDGE EXTENDING WEST SOUTHWEST THROUGH THE WATERS
JUST NORTH OF THE LOCAL AREA THROUGH NEXT WEEKEND.

AT LOWER LEVELS...A WEAK TROPICAL WAVE IS MOVING THROUGH THE
CARIBBEAN WATERS AND IS BEGINNING TO SEND A FEW SHOWERS OVER THE
LOCAL ISLANDS. THIS WILL BE FOLLOWED BY A SECOND WAVE MOVING
THROUGH THE AREA MONDAY NIGHT AND TUESDAY. A GENERALLY MOIST AIR
MASS PREVAILS THROUGH THE REST OF THE WEEK IN EAST SOUTHEAST FLOW
GENERATED BY A PERSISTENT HIGH IN THE CENTRAL AND NORTHEAST
CENTRAL ATLANTIC AND EXTENDING ACROSS THE LOCAL WATERS NORTH OF
THE AREA BETWEEN 20 AND 30 NORTH LATITUDE.

&&

.DISCUSSION...SHOWERS MOVING TOWARD THE WEST FIRST APPEARED IN
THE WATERS SOUTH OF SAINT CROIX EARLY LAST NIGHT AND ARE NOW
WIDELY SCATTERED IN A BAND BETWEEN SAINT CROIX AND MAINLAND PUERTO
RICO...EXTENDING WEST SOUTHWEST TO THE EDGE OF THE FORECAST AREA
SOUTH OF CABO ROJO. THE MIMIC PRODUCT SUGGESTS THAT THIS BAND OF
SHOWERS WILL HELP INITIATE SCATTERED CONVECTION LATE MORNING
ACROSS PUERTO RICO AND DOWN STREAM FROM THE NORTHERN U.S. VIRGIN
ISLANDS. THE NAM5 MODELS SHOWS SCATTERED TO NUMEROUS SHOWERS FROM
EL YUNQUE TO HORMIGUEROS WITH A FEW BREAKS THIS AFTERNOON...BUT EXPECT
SHOWERS AND SCATTERED THUNDERSTORMS IN PARTS OF SOUTHWEST PUERTO
RICO WITH LOCALLY HEAVY RAIN. CURRENTLY THE NAM ALSO SHOWS
MOISTURE MOVING INTO EASTERN PUERTO RICO MONDAY MORNING AND HAVE
BOOSTED POPS TO CORRESPOND. MOISTURE INCREASES IN THE AREA UNTIL
THE PASSAGE OF A WEAK TROPICAL WAVE SOUTH OF THE AREA AROUND
27/06Z...BUT BEST SHOWER ACTIVITY MAY BE ON MONDAY. ANOTHER PUFF
OF DEEP MOISTURE WILL MOVE THROUGH THE CARIBBEAN JUST SOUTH OF THE
AREA THURSDAY NIGHT AND AID SHOWER PRODUCTION THURSDAY NIGHT AND
FRIDAY. MODEL FORECASTS BEYOND THIS WEEK HAVE BEEN TOO
INCONSISTENT TO DRAW ANY SPECIFIC CONCLUSIONS...BUT THEY HAVE BEEN
SHOWING INCREASED TROPICAL ACTIVITY.

&&

.AVIATION...
VFR THIS MRNG XCP POSSIBLE/BRIEF MVFR IN ISOLD SHRA
TNCM/TKPK/TISX. AREAS OBSCD MTNS AFT 25/16Z ACRS W PR IN SHRA/TSRA
WI CHC MVFR AT TJMZ. INCR TSRA LATE TONITE/MON IN TROPICAL WAVE.
WINDS BLO FL100 E 16-28 KT BCMG 12-20 TONITE/MON.

&&

.MARINE...WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
CONDITIONS FOR AT LEAST THE NEXT 5 DAYS...BUT SMALL CRAFT WILL
NEED TO EXERCISE CAUTION FOR AREAS OF WINDS EXCEEDING 17 KNOTS IN
THE EXPOSED WATERS. SHOWERS AND THUNDERSTORMS INCREASE THROUGH
MONDAY NIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 89 79 / 30 60 60 30
STT 89 79 90 80 / 20 60 60 50

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
313 PM AST SUN AUG 25 2013

.SYNOPSIS...MID-UPPER LEVEL RIDGE WILL HOLD THROUGH THE END OF THE WEEK.
A TROPICAL WAVE WILL MOVE ACROSS THE AREA MON NIGHT. ANOTHER
TROPICAL WAVE WILL MOVE THROUGH THE AREA FRI.

&&

.DISCUSSION...A TROPICAL WAVE APPROACHING THE LEEWARD ISLANDS WILL
MOVE ACROSS THE AREA MON-MON NIGHT AND PROMISES TO BRING A CLOUDY
AND SHOWERY DAY TOMORROW TO MOST PLACES. WHILE THERE COULD BE SOME
POCKETS OF HEAVY RAINFALL AND ISOLATED FLASH FLOODING...FLOODING
THREAT DOES NOT LOOK SIGNIFICANT ENOUGH TO WARRANT ANY TYPE OF
SPECIAL PRODUCTS. TROPICAL WAVE EXITS THE AREA EARLY TUE WITH
CONDITIONS EXPECTED TO IMPROVE DURING THE AFTERNOON.

A PAIR OF TROPICAL WAVES ACROSS THE CNTRL ATLC ARE EXPECTED TO
DAMPEN OUT AS THEY MOVE WESTWARD ACROSS THE ATLC INTO THE
CARIBBEAN. OVERALL...EXPECT A TYPICAL PATTERN OF AFTERNOON
CONVECTION OVER WESTERN PR EACH DAY WITH RAINFALL LIKELY TO BE
SLIGHTLY BELOW NORMAL.

TROPICAL WAVE FCST TO EXIT THE AFRICAN CONTINENT TONIGHT IS
EXPECTED TO BECOME A TROPICAL CYCLONE BY THE END OF THE WEEK AND
REACH 55W BY 12Z SUN SEP 01.

&&

.AVIATION...AFTERNOON CONVECTION OVER THE INTERIOR AND SW PR WILL
DISSIPATE AFT 25/22Z. THIS ACTIVITY IS NOT EXPECTED TO AFFECT THE
LOCAL TAF SITES THE REST OF TODAY. HOWEVER...A SFC TROUGH WILL
INCREASE THE POTENTIAL FOR SHRA/TSRA ACROSS THE FLYING AREA ON
MONDAY. STRONG WINDS OF AROUND 30 KT CAN BE EXPECTED BETWEEN FL050
AND FL100. AT THE SFC...WINDS WILL BE MAINLY FM THE NE AT 10 TO 20
KT.

&&

.MARINE...SEAS 4-6 FT AND WINDS UP TO 20 KT MON-MON NIGHT. SEAS
SUBSIDING 3-5 FT TUE. NMRS SHOWERS AND SCT TSRA MON-MON NIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 81 88 80 88 / 50 70 30 30
STT 82 82 81 82 / 50 70 50 50

[cycloneye]

Good morning. A Tropical Wave is moving thru PR today bringing scattered showers.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
459 AM AST MON AUG 26 2013

.SYNOPSIS...AT UPPER LEVELS...HIGH PRESSURE DOMINATES THE LOCAL
AREA WITH WINDS AT 250 MB GENERALLY LESS THAN 20 KT.

AT MID LEVELS...HIGH PRESSURE MAINTAINS A PRESENCE BETWEEN 20 AND
30 NORTH LATITUDE NORTH OF THE LOCAL AREA THROUGH EARLY NEXT WEEK.

AT LOWER LEVELS...A RIDGE EXTENDS OUT OF HIGH PRESSURE IN THE
NORTHEAST CENTRAL ATLANTIC SOUTHWEST TO WATERS NORTH OF THE LOCAL
AREA MAINTAINING MODERATE TO FRESH TRADE WIND FLOW. A TROUGH
IS PASSING THROUGH THE AREA TODAY...A TROPICAL WAVE IS EXPECTED ON
FRIDAY.

&&

.DISCUSSION...LOCAL WATERS ARE PEPPERED WITH SMALL SHOWERS THAT
LEAVE MINOR ACCUMULATIONS WHEN THEY MOVE OVER LAND IN THE EAST
NORTHEAST FLOW AHEAD OF A TROUGH THAT LIKELY HAS ALREADY PASSED
SAINT CROIX OWING TO THE VEERING WINDS THERE. SAN JUAN RECEIVED
0.15 INCH DURING THE FIRST HOUR OF THE DAY. SHOWERS WILL INCREASE
WITH INCREASING MOISTURE BEHIND THE WAVE AND CONTRIBUTE TO
NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS OVER PUERTO RICO AND
THE U.S. VIRGIN ISLANDS. MOISTURE AT THE TOP OF THE LOWER LEVELS
OF THE ATMOSPHERE DIMINISHES ON TUESDAY...BUT LOW LEVEL MOISTURE
IS AGAIN SEEN ON FRIDAY. IN FACT LOWER LEVEL MOISTURE IS PATCHY
THROUGH MOST OF THE WEEK INCREASING SOMEWHAT ON FRIDAY WITH THE
NEXT WAVE.

THE GFS HAS DEVELOPED TROPICAL SYSTEMS IN EACH OF THE LAST
SEVERAL DAYS` RUNS...BUT IS NOT CONSISTENT IN THE STRENGTH OF
THOSE SYSTEMS. THE FIRST TROPICAL WAVE TO LEAVE AFRICA THIS WEEK
IS NOW MOVING TOWARD THE AREA...HOWEVER THE GFS HAS BEEN SHIFTING
THE CENTER OF THIS SYSTEM TOWARD THE CARIBBEAN WITH EACH
SUCCESSIVE RUN. THE LATEST MODEL RUN...THAT OF 26/00Z...SHOWS
ONLY A WEAK LOW PASSING SOUTH OF THE AREA ON THE DAY AFTER LABOR
DAY. THE ECMWF DOES NOT DEVELOP THIS LOW STRONGLY AND SHOWS IT
PASSING NORTHEAST OF THE LEEWARD ISLANDS IN THE SAME TIME FRAME.
THEREFORE IT IS TOO EARLY TO CONCLUDE ANYTHING ABOUT A TROPICAL
SYSTEM PASSING THROUGH THE AREA BEYOND SATURDAY AND THE FORECAST
WAS NOT ALTERED. OTHER LOWS CAN ALSO BE SEEN IN THE TROPICAL
ATLANTIC LATE IN THE 10 DAY PERIOD IN THIS MODEL RUN...BUT THE
NEXT ONE IS CURRENTLY TURNING NORTHWEST IN THE MID ATLANTIC.

&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED FOR THE REST OF THE EARLY MORNING
HOURS ACROSS ALL TERMINALS...WITH MVFR CONDITIONS OVER TNCM AND
TKPK. AFTER 26/12Z...PERIODS OF MVFR CONDITIONS ARE EXPECTED FOR
ALL TAF SITES DUE TO A SFC TROUGH PASSING OVER THE LEEWARD
ISLANDS AND ALSO PR AFT 26/14Z. THIS WILL INCREASE THE POTENTIAL FOR
SHRA/TSRA ACROSS THE FLYING AREA AT LEAST UNTIL TONIGHT.
ALSO...AREAS OF MTN OBSCURATIONS ARE EXPECTED AFT 26/16Z OVER W PR
WITH POSSIBLE BRIEF IFR AT TJMZ. LOW LEVEL WINDS WILL BE MAINLY FM
THE ENE AT 10 TO 20 KT.

&&

.MARINE...WINDS CONTINUE MODERATE TO FRESH AND ARE MAINTAINING
SEAS OF AT LEAST 5 FEET IN EXPOSED WATERS WITH SOME 6 FOOT SEAS
EXPECTED TODAY IN THE OUTER WATERS OF THE ATLANTIC. LITTLE CHANGE
IS EXPECTED THIS WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 79 91 / 40 40 30 30
STT 79 90 80 89 / 60 60 40 40

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
307 PM AST MON AUG 26 2013

.SYNOPSIS...MID-UPPER LEVEL RIDGE WILL REMAIN THE DOMINANT WX
FEATURE THROUGH THE EARLY NEXT WEEK. A TROPICAL WAVE WILL MOVE
ACROSS TONIGHT WITH ANOTHER ONE EXPECTED FRI.

&&

.DISCUSSION...A TROPICAL WAVE OVR THE ANEGADA PASSAGE WILL MOVE
ACROSS THE AREA TONIGHT. THIS WAVE WILL BRING AN INCREASE IN
SHOWERS AND THUNDERSTORMS OVER EASTERN PR...USVI AND ESPECIALLY
THE CARIBBEAN COASTAL WATERS TONIGHT THROUGH EARLY TUE. SHOWERS
MAY CONTAIN HEAVY RAINFALL THAT COULD RESULT IN ISOLATED FLASH
FLOODING. TROPICAL WAVE WILL EXIT THE AREA BY 12Z TUE WITH SHARP
DRYING EXPECTED TOMORROW. 800 MB DEWPOINT DEPRESSIONS ARE VERY
LARGE GREATER THAN 15C AND LYR REL HUM ARE VERY LOW...SO I REDUCED
CLOUDS AND POPS SIGNFICANTLY FOR TOMORROW WITH ONLY ISOLD CVRG OUT WEST.
UNEVENTFUL WED-THU WITH BELOW NORMAL RAINFALL.

ANOTHER TROPICAL WAVE CURRENTLY ALONG 41W WILL REACH THE AREA FRI
BRINGING BETTER CHANCES OF RAIN FOR FRI AND SAT.

A THIRD TROPICAL WAVE ALONG 23W HAS A 30% CHANCE OF TC DEVELOPMENT
IN NEXT FIVE DAYS AND IS EXPECTED TO REACH THE EASTERN CARIBBEAN
SEA NEXT TUE SEP 03. MODELS ARE MUCH WEAKER BUT ALSO FARTHER SOUTH
WITH MOST ENSEMBLE MEMBERS SHOWING A TROPICAL DEPRESSION OR WEAK
TROPICAL STORM MOVING JUST SOUTH OF PR. THIS WAVE OR POSSIBLE
TROPICAL CYCLONE HAS THE POTENTIAL TO BE A SIG RAIN MAKER.

&&

.AVIATION...CONDITIONS EXPECTED TO IMPROVE AFTER 26/22Z OVER THE
LOCAL TERMINALS...LEAVING MAINLY VFR CONDITIONS. HOWEVER...SHRA/TSRA
ACROSS THE LOCAL WATERS MAY BRIEFLY AFFECT TIST/TISX AND TJSJ AS
THEY PASS BY...SO MVFR CONDITIONS ARE NOT OUT OF THE QUESTION. TEMPO
LEFT OUT OF TAF DUE TO UNCERTAINTY OF TIMING BUT THERE ARE SHRA/TSRA
JUST EAST OF THE USVI. WINDS WILL BE MAINLY FROM THE EAST AT AROUND
10 KNOTS TONIGHT. IMPROVING CONDITIONS EXPECTED AFTER 27/12Z.

&&

.MARINE...SEAS 3-5 FT AND WINDS AROUND 15 KT. NMRS TSRA TONIGHT OVER
BOTH ATLANTIC AND CARIBBEAN COASTAL WATERS. WINDS AND WAVES HIGHER
IN TSTMS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 79 91 / 60 10 10 10
STT 79 90 80 89 / 50 0 10 10

[cycloneye]

Good morning. A few showers will move thru PR today but all eyes are towards a Tropical Wave in the Eastern Atlantic that may bring significant rain and strong winds to the Eastern Caribbean stating on Sunday so stay tuned for more information.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
506 AM AST TUE AUG 27 2013

.SYNOPSIS...AT UPPER LEVELS...HIGH PRESSURE DOMINATES THE LOCAL
AREA EXCEPT FOR A WEAK TROUGH THAT DIGS SOUTHWEST OVER THE AREA
AND BREAKS UP THE RIDGE OVER THE UPC0MING WEEKEND.

AT MID LEVELS...HIGH PRESSURE WILL REMAIN NORTH OF THE LOCAL AREA
THROUGH EARLY NEXT WEEK. A WEAK TROUGH WILL MOVE INTO THE
CARIBBEAN TUESDAY AND WEDNESDAY.

AT LOWER LEVELS...HIGH PRESSURE IN THE NORTHEAST AND LOW PRESSURE
OVER COLOMBIA AND THE SOUTHWEST CARIBBEAN WILL MAINTAIN MODERATE
TO FRESH TRADE WINDS OVER THE LOCAL AREA THROUGH AT LEAST THE
WEEKEND. A TROPICAL WAVE WILL MOVE INTO THE CARIBBEAN SUNDAY NIGHT
AND PASS MAINLY SOUTH OF THE AREA MONDAY AND TUESDAY.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE ACTIVE OVER THE AREA
LAST NIGHT AND EARLY THIS MORNING. SHOWER ACTIVITY ACTUALLY
INCREASED AFTER MIDNIGHT WEST OF THE U.S. VIRGIN ISLANDS. RADAR
SHOWED OVER AN INCH FELL IN EASTERN AND SOUTHEASTERN PUERTO RICO
AFTER MIDNIGHT. RAIN WAS NOT OBSERVED IN THE U.S. VIRGIN ISLANDS
AFTER MIDNIGHT...BUT A FEW HUNDREDTHS WERE SEEN DURING THE
PREVIOUS EVENING.

THE GFS IS SHOWING AN ABRUPT DRYING THIS MORNING...AND PRECIPITABLE
WATER HAD DROPPED TO 1.8 INCHES AT SAINT CROIX AS OF ABOUT 2 AM
AST INDICATING THAT DRIER AIR WAS ARRIVING. HOWEVER CONSIDERABLE
MOISTURE IS STILL PRESENT AND BOTH THE GFS AND WRF MODELS WERE
INDICATING POCKETS OF 2 PLUS INCHES OF PRECIPITABLE WATER
LINGERING OVER OR NEAR WESTERN PUERTO RICO AS LATE AS 27/18Z. ALSO
THE NAM5 WAS SHOWING POPS OF OVER 85 PERCENT IN BOTH WESTERN AND
CENTRAL PUERTO RICO DURING THE AFTERNOON. THEREFORE HAVE INCREASED
POPS OVER THE ISLAND TO UP TO 50 PERCENT TO REFLECT SHOWER AND
THUNDERSTORM ACTIVITY. NOTE ALSO THAT LOW CLOUDS ARE PRESENT IN
THE INFRA RED IMAGERY AND MOVING TOWARD PUERTO RICO AT THIS TIME
AS FURTHER INDICATIONS THAT MOISTURE WILL NOT END QUICKLY.
ALTHOUGH MOISTURE DROPS SIGNIFICANTLY TONIGHT IT ALSO REBOUNDS IN
TIME FOR AFTERNOON CONVECTION TOMORROW AND EXPECT SHOWERS AND
THUNDERSTORMS TO RE-DEVELOP...ESPECIALLY IN WESTERN PUERTO
RICO...WEDNESDAY AFTERNOON IN A TYPICAL SUMMERTIME PATTERN. THEN
AFTER A SLIGHT DIP...MOISTURE INCREASES SLIGHTLY OVER WEDNESDAY FOR
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ON THURSDAY. SHOWERS
END ON THURSDAY AS DRYING AHEAD OF THE NEXT TROPICAL
WAVE...EXPECTED ON FRIDAY...TAKES PLACE. THE WEEKEND THEN APPEARS
TO BE RELATIVELY MOIST.

FOR THOSE THAT HAVE BEEN FOLLOWING THE EVOLUTION OF THE GFS
FORECAST OF TROPICAL ACTIVITY SET TO ENTER THE CARIBBEAN NEXT
WEEK...THE LATEST RUN...27/00Z...SHOWED A TROPICAL WAVE...OR
PERHAPS A TROPICAL DEPRESSION...ENTERING THE CARIBBEAN SUNDAY NIGHT
AND MOVING SOUTH OF THE FORECAST AREA ON MONDAY NIGHT. THIS
SCENARIO BRINGS MOISTURE TO THE AREA AFT 04/00Z...BUT NOT
SIGNIFICANT WINDS. SHOWER AND THUNDERSTORM ACTIVITY COULD BRING
STRONG GUSTS OF COURSE...AND SIGNIFICANT RAINS ARE STILL POSSIBLE
THEN. THE ECMWF 27/00Z RUN SHOWS A SIMILAR STRENGTH SYSTEM PASSING
NORTHWEST OVER 20 NORTH 60 WEST WITH NEGLIGIBLE EFFECT TO THE
LOCAL AREA. THESE MODELS SHOULD RESOLVE THEIR DIFFERENCES WITHIN 3
TO 4 DAYS...THOUGH AT THIS TIME EXPECT THE SOLUTIONS TO BE
SOMEWHERE BETWEEN THE TWO AND CURRENTLY LEAN TOWARD THE GFS.

&&

.AVIATION...
VFR CONDITIONS EXPECTED ACROSS MOST OF THE TAF SITES THIS
MORNING...EXCEPT POSSIBLE BRIEF MVFR CONDITIONS IN SHRA AT TJSJ
AND TJPS AND MN OBSCURATIONS IN EASTERN PUERTO RICO. AFT 27/16Z...AREAS OF
MTN OBSCURATIONS ARE EXPECTED OVER W PR WITH PERIODS OF MVFR AT
TJMZ AND POSSIBLY TJBQ. ALSO...VCSH ARE POSSIBLE AT TJSJ AFTER
27/16Z. LOW LEVEL WINDS WILL CONTINUE MAINLY FROM THE EAST AT 10
TO 15 KTS.

&&

.MARINE...WINDS UP TO 17 KNOTS AND SEAS BELOW 5 FEET ARE EXPECTED
THROUGH WEDNESDAY. HIGHEST SEAS MAY REACH 6 FEET THURSDAY NIGHT
AND FRIDAY IN LOCAL OUTER WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 90 79 / 60 30 30 30
STT 90 80 90 80 / 40 20 40 30

[cycloneye]

.SYNOPSIS...MID TO UPPER LEVEL HIGH PRESSURE RIDGE REMAINED ANCHORED
ACROSS THE ENTIRE EASTERN CARIBBEAN. THIS HELPED TO PROVIDE GOOD
VENTILATION ALOFT EARLIER TODAY WHICH AIDED IN DEEP CONVECTIVE
DEVELOPMENT IN ASSOCIATED WITH A SURFACE TROUGH WHICH EXITED THE
REGION EARLIER THIS AFTERNOON. LATEST MODEL GUIDANCE SUGGESTS THAT
THE THE UPPER RIDGE WILL HOLD IN PLACE AT LEAST THROUGH THURSDAY...
BUT WILL THEN BEGIN TO ERODE BY FRIDAY...AS TUTT NORTH OF THE AREA
DIGS SOUTHWARDS AND BECOMES AMPLIFIED ACROSS THE NORTHEASTERN CARIBBEAN.
LATEST SATELLITE IMAGERY AND MODEL GUIDANCE BOTH SHOW DRIER AIR FILTERING
FROM THE EAST DURING THE REST OF THE AFTERNOON AND EVENING HOURS. THIS
SOMEWHAT DRIER PATTERN IS TO CONTINUE AT LEAST UNTIL THURSDAY...AS THE
SURFACE TROUGH EXITS THE REGION AND SURFACE HIGH PRESSURE BUILDS FURTHER
WESTWARD ACROSS THE NORTHEASTERN CARIBBEAN.

&&

.DISCUSSION...EXPECT SHOWER AND ISOLATED THUNDERSTORM ACTIVITY TO
CONTINUE TO DIMINISH ACROSS THE REGION DURING THE REST OF THE
AFTERNOON AND EVENING HOURS. HOWEVER PATCHES OF MOISTURE TRAILING
THE EXITING TROUGH WILL MOVE ACROSS THE REGION AND BRING SOME
QUICK PASSING SHOWERS ACROSS PARTS OF THE ISLANDS AND LOCAL WATERS
OVERNIGHT. ON WEDNESDAY AND THURSDAY...MODEL GUIDANCE SUGGESTS
DRIER AIR ACROSS THE REGION WITH RAPID DECREASE IN PRECIPITABLE
WATER TO LESS THAN 1.50 INCHES. HOWEVER...EVEN THOUGH THIS SLOT OF
DRIER AIR IS MOVING IN...EXPECT AVAILABLE MOISTURE LOW LEVEL
CONVERGENCE TO BE SUFFICIENT ENOUGH TO COMBINE WITH THE LOCAL AND
DIURNAL EFFECTS TO PRODUCE ISOLATED TO SCATTERED CONVECTION EACH
DAY...ESPECIALLY ACROSS PARTS OF THE INTERIOR AND WESTERN SECTIONS
OF PUERTO RICO.

FOR THE LONG TERM...GFS MODEL GUIDANCE HAS SO FAR INITIALIZED FAIRLY
WELL AND TENDS TO LEAN TOWARDS A WETTER PATTERN BY LATE FRIDAY AND
INTO THE UPCOMING WEEKEND AS THE NEXT TROPICAL WAVE IS FORECAST TO
ENTER AND MOVE ACROSS THE REGION.

&&

.AVIATION...VFR CONDITIONS EXPECTED ACROSS THE LOCAL TERMINALS FOR
THE NEXT 24 HOURS...WITH THE EXCEPTION OF AFTERNOON CONVECTION ACROSS
WESTERN PR AFTER 28/17Z WHICH COULD CAUSE MVFR/IFR CONDITIONS FOR
TJMZ...OTHERWISE FAIR WEATHER IS EXPECTED OVERNIGHT. SURFACE WINDS
ARE EXPECTED TO REMAIN EASTERLY AT 10 TO 15 KNOTS WITH SOME GUSTS
UNTIL 28/00Z...DECREASING SLIGHTLY THEREAFTER.

&&

.MARINE...SEAS ARE EXPECTED TO REMAIN AT 5 FEET OR LESS WITH WINDS
OF 18 KNOTS OR LESS OVERNIGHT AND THROUGH AT LEAST THURSDAY. SMALL
CRAFT OPERATORS SHOULD EXERCISE CAUTION ACROSS THE LOCAL OFFSHORE
WATERS OVERNIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 89 79 88 / 30 30 30 40
STT 79 89 80 89 / 30 40 40 30

[cycloneye]

Good morning. It looks like rainy pattern will establish in the next few days as Troughs and Tropical Waves move thru. Still watching the wave in Central Atlantic.



AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
439 AM AST WED AUG 28 2013

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL MEANDER ACROSS THE LOCAL AREA
THROUGH THURSDAY. THEN...A TUTT WILL MOVE SOUTHWESTWARD INTO THE
NORTHEAST CARIBBEAN ON FRIDAY...PERSISTING NEAR THE ISLANDS
THROUGH EARLY NEXT WEEK. AT LOW LEVELS...A TROPICAL WAVE NEAR 51W
THIS MORNING WILL ALSO MOVE ACROSS THE AREA ON FRIDAY. IN GENERAL...
A WETTER PATTERN WILL ESTABLISH ACROSS THE LOCAL ISLANDS FRIDAY
AND SATURDAY AS THE TUTT RELOCATES AND AMPLIFIES OVER THE REGION
AND THE TROPICAL WAVE MOVES THROUGH THE FORECAST AREA.

&&

.DISCUSSION...SATELLITE IMAGERY AS WELL AS RADAR DATA SHOWED
SCATTERED SHOWERS MOVING WESTWARD ACROSS THE SURROUNDING WATERS OF
PUERTO RICO AND THE U.S. VIRGIN ISLANDS OVERNIGHT. A FEW PASSING
SHOWERS MOVED OVER EASTERN PUERTO RICO...LEAVING MINIMAL RAINFALL
ACCUMULATION. A MOISTURE BAND IS EXPECTED TO APPROACH THE LOCAL
ISLANDS AFTER 12Z TODAY...BRINGING A SLIGHT INCREASE IN TRADE WIND
SHOWERS ACROSS THE LOCAL WATERS AND THE WINDWARD AREAS THIS MORNING.
MOISTURE ADVECTION AT THE TIME OF MAXIMUM HEATING WILL ALSO HELP
TO THE FORMATION OF SHOWERS AND THUNDERSTORMS ACROSS THE INTERIOR
AND WEST PORTIONS OF PUERTO RICO THIS AFTERNOON. MODELS SUGGEST THAT
THE PRECIPITABLE WATER VALUES ASSOCIATED WITH THIS MOISTURE BAND WILL
PEAK TONIGHT. THEREFORE...EXPECT ANOTHER ROUND OF SCATTERED SHOWERS
ACROSS THE WINDWARD AREAS TONIGHT AND OVERNIGHT. MOISTURE DECREASES
ON THURSDAY AHEAD OF THE NEXT TROPICAL WAVE. MODELS TENDS TO A WETTER
SOLUTION FRIDAY AND SATURDAY AS THE TROPICAL WAVE AND A TUTT ALOFT
MOVE INTO THE LOCAL AREA. CONSEQUENTLY...SHOWER AND THUNDERSTORM
ACTIVITY WILL INCREASE CONSIDERABLY DURING THIS TIME PERIOD.

LONG RANGE...AN ACTIVE WEATHER PATTERN IS EXPECTED MIDWEEK NEXT
WEEK. THE SYSTEM OF CONCERN IS A TROPICAL WAVE OVER WEST AFRICA.
MODELS BRING THE SYSTEM CLOSE TO THE FORECAST AREA AND SUGGEST
ORGANIZED CONVECTION WITH THIS SYSTEM. THE NATIONAL HURRICANE
CENTER...NHC...IS MONITORING THIS PERTURBATION FOR THE POSSIBILITY OF
TROPICAL CYCLONE FORMATION DURING THE NEXT 5 DAYS. PLEASE REFER TO
TROPICAL WEATHER OUTLOOK FOR MORE DETAILS.

&&

.AVIATION...VFR CONDITIONS EXPECTED AT ALL TAF SITES FOR THE NEXT
24 HOURS...EXCEPT AT TJMZ AND TJBQ WHERE SHRA/TSRA LIKELY AFTER
28/17Z. SURFACE WINDS ARE EXPECTED TO REMAIN EASTERLY AT 10 TO 15
KNOTS WITH SOME GUSTS.

&&

.MARINE...MODERATE WIND AND SEAS OF 2-4 FEET WILL PREVAIL ACROSS
THE COASTAL WATERS. LOCALLY FRESH WINDS AND SEAS UP TO 5 FEET CAN
BE EXPECTED FRIDAY AND SATURDAY WITH THE PASSAGE OF THE TROPICAL
WAVE.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 81 89 78 / 20 20 40 30
STT 89 82 90 82 / 30 40 40 40

[cycloneye]

2 PM Tropical Weather Outlook.

SHOWER ACTIVITY ASSOCIATED WITH A TROPICAL WAVE LOCATED ABOUT 1400
MILES EAST OF THE LESSER ANTILLES REMAINS LIMITED. ENVIRONMENTAL
CONDITIONS COULD BECOME A LITTLE MORE FAVORABLE FOR DEVELOPMENT
OVER THE WEEKEND AS THE WAVE MOVES WESTWARD AT ABOUT 15 MPH AND
APPROACHES THE LESSER ANTILLES. THIS SYSTEM HAS A LOW CHANCE...NEAR
0 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48
HOURS...AND A LOW CHANCE...20 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 5 DAYS.

[Gustywind]

2 PM Tropical Weather Discussion.


TROPICAL WAVE EXTENDS AN AXIS ALONG 19N38W TO A 1012 MB LOW
EMBEDDED IN THE MONSOON TROUGH TO 09N38W AND IS MOVING W NEAR 10
KT. TOTAL PRECIPITABLE WATER IMAGERY SHOW THE WAVE IS WITHIN A
MODERATE TO HIGH MOIST ENVIRONMENT. ISOLATED MODERATE CONVECTION
IS WITHIN 150 NM OF ITS AXIS.

[cycloneye]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
319 PM AST WED AUG 28 2013

.SYNOPSIS...MID TO UPPER LEVEL HIGH PRESSURE RIDGE PERSISTED ACROSS
THE REGION TODAY TO MAINTAIN AN OVERALL SUBSIDENT AIR MASS ALOFT.
EXPECT RIDGE TO REMAIN IN PLACE THROUGH THURSDAY BUT WILL BEGIN TO
GRADUALLY ERODE BY FRIDAY AND INTO THE WEEKEND...AS TUTT NORTH OF
THE AREA DIGS SOUTHWARDS ACROSS THE NORTHEASTERN CARIBBEAN AND BECOME
AMPLIFIED. LATEST SATELLITE IMAGERY AND MODEL GUIDANCE CONTINUED TO
SUGGEST OVERALL DRIER AIR MASS ACROSS THE REGION THROUGH THURSDAY.
HOWEVER...PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE MODERATE
TRADE WIND FLOW CONTINUED TO MOVE WESTWARD ACROSS THE REGION. THIS
PATTERN IS EXPECTED TO CONTINUE AT LEAST UNTIL THURSDAY AS SURFACE
HIGH PRESSURE WILL BUILD FURTHER WESTWARD ACROSS THE NORTHEASTERN
CARIBBEAN. MEANWHILE... A TROPICAL WAVE/INDUCED TROUGH WITH AXIS
NEAR 55 WEST IS EXPECTED TO CROSS THE LESSER ANTILLES LATE THURSDAY
THEN MOVE ACROSS THE AREA FRIDAY THROUGH SATURDAY.

&&

.DISCUSSION...SATELLITE IMAGERY AS WELL AS THE DOPPLER WEATHER RADAR
SHOWED QUICK PASSING SHOWERS EMBEDDED IN THE TRADE WIND FLOW MOVING
ACROSS THE REGION THROUGHOUT THE DAY. DIURNALLY INDUCED CONVECTION
DEVELOPED ACROSS PARTS OF THE NORTH CENTRAL AND WEST SECTIONS OF PUERTO
RICO DURING THE AFTERNOON...THEN QUICKLY MOVED WEST LEAVING NO SIGNIFICANT
RAINFALL ACCUMULATIONS SO FAR.

OVERALL THE UPPER LEVEL PATTERN SHOULD REMAIN UNCHANGED THROUGH AT
LEAST THURSDAY...AS SOMEWHAT DRIER CONDITIONS IS EXPECTED TO PREVAIL.
THEREAFTER...THE TUTT IS TO BECOME AMPLIFIED OVER THE REGION. THIS
WILL HELP DESTABILIZE THE NORTHEASTERN CARIBBEAN ON FRIDAY AND THROUGH
THE WEEKEND. IN ADDITION...TROPICAL MOISTURE ACCOMPANYING THE
TROPICAL WAVE ON FRIDAY AND SATURDAY WILL AID IN ENHANCING CONVECTION
ACROSS THE REGION AND THUS INCREASE POTENTIAL FOR ACTIVE WEATHER AT
LEAST THROUGH SATURDAY. THIS WILL BE FOLLOWED BY A WIND SURGE AS THE
LOCAL PRESSURE GRADIENT TIGHTENS ACROSS THE REGION IN ADVANCE OF
ANOTHER TROPICAL WAVE FORECAST TO ENTER THE EASTERN CARIBBEAN LATE
SUNDAY OR MONDAY...THEN AFFECT THE LOCAL REGION DURING THE EARLY PART
OF NEXT WEEK. ALL IN ALL MODEL GUIDANCE SUGGEST A WETTER AND VERY
UNSTABLE ENVIRONMENT DURING THE EARLY PART OF NEXT WEEK AS ANOTHER
DISTANT TROPICAL WAVE NOW OVER THE TROPICAL ATLANTIC IS EXPECTED
TO MOVE ACROSS TO REGION. WILL HOWEVER CONTINUE TO MONITOR TO SEE
HOW THIS UNFOLDS.

&&

.AVIATION...MAINLY VFR CONDITIONS EXPECTED FOR THE REST OF TODAY AS
THE SHRA/TSRA LEAVES WESTERN PR AFTER 28/20Z. HOWEVER...VCSH ACROSS
THE LOCAL TERMINALS ARE POSSIBLE. WINDS EXPECTED TO REMAIN EASTERLY
WITH SEA BREEZE VARIATIONS AT AROUND 10 KNOTS WITH
GUSTS...DECREASING OVERNIGHT. SHRA/TSRA DEVELOPMENT IS ONCE AGAIN
EXPECTED AFTER 29/16Z...ESPECIALLY ACROSS CENTRAL AND WESTERN
PR...LIKELY AFFECTING TJMZ/TJBQ AND THE VICINITY OF TJPS AND TJSJ.

&&

.MARINE...MODERATE TO LOCALLY FRESH WIND OF 17 KNOTS OR LESS AND SEAS
OF 5 FEET OR LESS WILL PREVAIL ACROSS THE COASTAL WATERS OVERNIGHT.
LOCALLY FRESH WINDS AND SEAS UP TO 5 FEET CAN BE EXPECTED FRIDAY AND
SATURDAY WITH THE PASSAGE OF THE TROPICAL WAVE.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 89 78 90 / 20 40 30 40
STT 79 89 79 90 / 40 40 40 30

[cycloneye]

Good morning. Tropical Wave will move thru PR on Friday bringing plenty of shower activity. The following wave now in Central Atlantic will bring even more bad weather so stay tuned.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
459 AM AST THU AUG 29 2013

.SYNOPSIS...MID TO UPPER LEVEL RIDGE WILL CONTINUE TO INFLUENCE THE
LOCAL WEATHER UNTIL TONIGHT. AN UPPER TROUGH/TUTT APPROACHES FROM
THE NORTHEAST LATE TONIGHT AND FRIDAY. THE TUTT WILL AMPLIFY OVER THE
REGION ON FRIDAY...DESTABILIZING THE ATMOSPHERE ACROSS THE ISLANDS.
AT LOW LEVELS...A TROPICAL WAVE JUST EAST OF THE LESSER ANTILLES
THIS MORNING WILL REACH THE FORECAST AREA LATE TONIGHT/EARLY FRIDAY
MORNING. IN GENERAL...A WETTER PATTERN WILL ESTABLISH ACROSS THE
LOCAL ISLANDS LATE TONIGHT AND FRIDAY DUE TO THE INFLUENCE OF THE
TROPICAL WAVE AND THE UPPER LEVEL TROUGH/TUTT. THEN...TYPICAL
WEATHER PATTERN WITH CONVECTION EACH AFTERNOON IS EXPECTED DURING
THE LABOR WEEKEND.

&&

.DISCUSSION...DOPPLER RADAR IMAGERY SHOWED SCATTERED SHOWERS MOVING
WESTWARD ACROSS THE SURROUNDING WATERS OF PUERTO RICO AND THE U.S.
VIRGIN ISLANDS OVERNIGHT. SOME OF THESE SHOWERS MOVED INLAND ACROSS
THE USVI...CULEBRA...VIEQUES AND EASTERN PUERTO RICO. THE FAST
MOVEMENT OF THE SHOWERS RESULTED IN MINIMAL RAINFALL ACCUMULATIONS.
TRADE WIND SHOWERS WILL CONTINUE TO AFFECT THESE PORTIONS OF THE
ISLANDS THROUGH MID MORNING. DECENT MOISTURE COMBINED WITH THE LOCAL
TOPOGRAPHIC EFFECTS AND SEA BREEZE CONVERGENCE WILL COMBINE TO
PRODUCE SCATTERED TO NUMEROUS SHOWERS ALONG THE INTERIOR AND WEST
SECTIONS OF PUERTO RICO THIS AFTERNOON.

SATELLITE IMAGERY AS WELL AS SURFACE ANALYSIS INDICATE A SERIES OF
TROPICAL WAVE MOVING WESTWARD ACROSS THE TROPICAL ATLANTIC. THE FIRST
WAVE IS LOCATED NEAR 58W THIS MORNING AND THE SECOND WAVE IS ALONG
42W. MIMIC PWAT ANALYSIS SHOWS HIGH MOISTURE CONTENT WITH THE TWO
WAVES. ALL OPERATIONAL MODELS SUGGEST DEEP MOISTURE SURGING LATE
TONIGHT AND FRIDAY ASSOCIATED WITH THE TROPICAL WAVE JUST EAST OF
THE LESSER ANTILLES. THE MOISTURE ADVECTION WILL BE IN PHASE WITH
THE ARRIVAL OF THE UPPER TROUGH/TUTT OVER THE AREA. LATEST GUIDANCE
SUGGEST THE PRECIPITABLE WATER WILL PEAK AT 1.9 INCHES BETWEEN
30/00Z AND 30/18Z. AS A RESULT...SHOWER AND THUNDERSTORM ACTIVITY
WILL INCREASE CONSIDERABLY DURING THIS TIME PERIOD. MOISTURE LEVELS
WILL DECREASE TO NEAR NORMAL DURING THE WEEKEND AND EARLY NEXT WEEK.
THEN...MOISTURE ASSOCIATED WITH THE WAVE NEAR 42W WILL REACH THE LOCAL
REGION BY MIDWEEK NEXT WEEK. MODELS ALSO SUGGEST AN UNSETTLED WEATHER
PATTERN WITH THIS WAVE.

&&

.AVIATION...MOSTLY VFR CONDITIONS EXPECTED AT ALL TAF SITES WITH
PASSING SHOWERS IN AND AROUND TNCM/TKPK AND USVI TERMINALS THROUGH
THE DAY. SHRA/TSRA EXPECTED TO DEVELOP AFT 29/17Z AND MAY CAUSE MVFR
CONDITIONS AT TJMZ/TJBQ AND POSSIBLY TJSJ. WINDS EXPECTED TO REMAIN
EASTERLY AT 10 TO 15 KNOTS...SHIFTING EAST SOUTHEAST AFT 28/18Z. A
TROPICAL WAVE/INDUCED TROUGH IS EXPECTED TO MOVE ACROSS THE AREA
TONIGHT THROUGH FRIDAY.

&&

.MARINE...MODERATE WIND AND SEAS OF 2-4 FEET WILL PREVAIL ACROSS
MOST OF THE LOCAL WATERS. SEAS UP TO 5 FEET CAN BE EXPECTED ACROSS
THE OFFSHORE ATLANTIC WATERS. LOCALLY FRESH WINDS AND SEAS 4-6 FEET
CAN BE EXPECTED DURING THE LABOR WEEKEND.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 79 90 78 / 40 30 40 30
STT 88 82 90 80 / 30 40 30 40

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT THU AUG 29 2013

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

1. A TROPICAL WAVE LOCATED OVER WESTERN AFRICA IS MOVING WESTWARD AT 10
TO 15 MPH...AND AN AREA OF LOW PRESSURE COULD FORM AFTER THE WAVE
MOVES OFF THE COAST ON FRIDAY. SOME DEVELOPMENT OF THIS SYSTEM IS
POSSIBLE BEFORE THE ENVIRONMENT BECOMES UNFAVORABLE BY EARLY NEXT
WEEK. THIS SYSTEM HAS A LOW CHANCE...10 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A MEDIUM
CHANCE...30 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 5 DAYS WHILE IT MOVES NEAR THE CAPE VERDE ISLANDS.

2. SHOWER ACTIVITY ASSOCIATED WITH A TROPICAL WAVE LOCATED ABOUT 1000
MILES EAST OF THE LESSER ANTILLES REMAINS LIMITED. DEVELOPMENT...IF
ANY...WILL BE SLOW TO OCCUR DURING THE NEXT COUPLE OF DAYS WHILE
THE WAVE MOVES WESTWARD AT ABOUT 15 MPH AND APPROACHES THE LESSER
ANTILLES. AFTER THAT TIME...UPPER-LEVEL WINDS COULD INHIBIT FURTHER
DEVELOPMENT. THIS SYSTEM HAS A LOW CHANCE...NEAR 10 PERCENT...OF
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS...AND A LOW
CHANCE...20 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 5 DAYS.

FIVE-DAY FORMATION PROBABILITIES ARE EXPERIMENTAL IN 2013. COMMENTS
ON THE EXPERIMENTAL FORECASTS CAN BE PROVIDED AT...

HTTP://WWW.NWS.NOAA.GOV/SURVEY/NWS-SURVEY.PHP?CODE=ETWO

FORECASTER AVILA