[top]
000
FXCA62 TJSJ 190829
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
429 AM AST SUN MAY 19 2013
.SYNOPSIS...SURFACE HIGH PRESSURE EXTENDING SOUTHWARDS FROM THE
NORTHEASTERN ATLANTIC...WILL BE RE ENFORCED BY A SECONDARY AREA OF
HIGH PRESSURE...WHICH WILL ENTER THE NORTHWESTERN ATLANTIC LATER
TODAY...THEN SPREAD SOUTHWARDS INTO THE SOUTHWEST ATLANTIC.
SLIGHTLY AMPLIFIED MID TO UPPER LEVEL TROUGH JUST WEST OF THE AREA
AND HIGH PRESSURE RIDGE EXTENDING ACROSS THE LESSER ANTILLES INTO
THE EASTERN CARIBBEAN...WILL MAINTAIN A DOMINANT WEST TO SOUTHWEST
WIND FLOW ALONG WITH A FAIRLY DRY AND CONVERGENT UPPER LEVEL
PATTERN ACROSS THE REGION THROUGH AT LEAST MONDAY. UPPER TROUGH IS
TO THEN SHIFT EASTWARD ACROSS THE REGION BY THURSDAY AND DURING
THE LATTER PART OF THE WORK WEEK.
&&
.DISCUSSION...THE OVERALL PATTERN CONTINUES TO BE INFLUENCED BY
HIGH PRESSURE NORTH OF THE AREA. EXPECT THE LOCAL PRESSURE GRADIENT
TO TIGHTEN ACROSS THE REGION...AS THE SURFACE HIGH BUILDS NORTH
OF THE AREA BY MID WEEK. THIS WILL CREATE MODERATE TO STRONG TRADE
WINDS. WEAK PERTURBATIONS MOVING WESTWARD IN THE PREVAILING WIND
FLOW WILL HELP TRANSPORT SHALLOW PATCHES OF LOW LEVEL TRADE WIND
MOISTURE ACROSS THE REGION FROM TIME TO TIME. EXPECT ONLY A FEW
PASSING SHOWERS TO AFFECT THE LOCAL WATERS DURING THE MORNING
HOURS...FOLLOWED BY SOME BRIEF SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM DURING THE AFTERNOON MAINLY OVER THE INTERIOR SECTIONS
OF PUERTO RICO. LIMITED OR NO SHOWER ACTIVITY IS EXPECTED OVER THE
VIRGIN ISLANDS TODAY.
LATEST GPS DERIVED IPW AND LAYERED PRECIPITABLE WATER PRODUCTS
SHOWED A GRADUAL DECLINE IN PRECIPITABLE WATER DURING THE PAST 24
HOURS. EXPECT THIS DECREASING TREND TO CONTINUE AT LEAST THROUGH
TUESDAY. EXPECT TROPICAL MOISTURE TO INCREASE ONCE AGAIN BY MID
WEEK AND INTO THE UPCOMING WEEKEND AS A LOW LEVEL CONVERGENCE ZONE
IS FORECAST TO DEVELOP ACROSS THE EASTERN CARIBBEAN...THEN LIFT
NORTHWARD ACROSS THE AREA. THIS ALONG WITH THE PROXIMITY OF THE
UPPER LEVEL TROUGH WILL RESULT IN BETTER CHANCE FOR ENHANCED EARLY
MORNING AND AFTERNOON CONVECTION. IN ADDITION BY LATE FRIDAY INTO
SATURDAY MODEL GUIDANCE ALSO SUGGESTS THAT AN EASTERLY WAVE WILL
ENTER THE EASTERN CARIBBEAN AND MOVE SOUTH OF THE AREA. THIS MAY
ALSO INCREASE THE CHANCES FOR MORE SHOWER ACTIVITY ACROSS THE
REGION. WILL HOWEVER CONTINUE TO MONITOR AND SEE HOW THIS UNFOLDS.
&&
.AVIATION...MOSTLY VFR CONDITIONS EXPECTED AT ALL TAF SITES UNTIL
19/16Z. MVFR AND POSSIBLE BRIEF IFR CONDITIONS WILL REMAIN LIKELY
BETWEEN 19/17Z-18/21Z ALONG THE CORDILLERA CENTRAL AND ACROSS TJMZ
AND TJBQ IN AREAS OF +SHRA/TSRA. MOUNTAINS TOPS MAY BE OBSCURED OVER
WRN INTERIOR OF PR. FOR TAF SITES ACROSS THE NORTHERN LEEWARD
ISLANDS...MAINLY VFR CONDITIONS ARE EXPECTED. TJSJ 19/00Z SOUNDING
INDICATES AND EASTERLY WIND FLOW AT 20 KNOTS OR LESS UP TO 15
KFT...BECOMING WESTERLY AND STRONGER ABOVE 15KFT.
&&
.MARINE...SMALL CRAFT SHOULD EXERCISE CAUTION DUE TO WINDS OF UP TO
19 KNOTS. SEAS ARE EXPECTED TO REMAIN AT 5 FEET OR LESS. THIS GENERAL
PATTERN IN MARINE CONDITIONS IS EXPECTED FOR THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 86 76 / 20 20 20 20
STT 87 77 87 78 / 20 20 20 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
72/09
000
FXCA62 TJSJ 190829
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
429 AM AST SUN MAY 19 2013
.SYNOPSIS...SURFACE HIGH PRESSURE EXTENDING SOUTHWARDS FROM THE
NORTHEASTERN ATLANTIC...WILL BE RE ENFORCED BY A SECONDARY AREA OF
HIGH PRESSURE...WHICH WILL ENTER THE NORTHWESTERN ATLANTIC LATER
TODAY...THEN SPREAD SOUTHWARDS INTO THE SOUTHWEST ATLANTIC.
SLIGHTLY AMPLIFIED MID TO UPPER LEVEL TROUGH JUST WEST OF THE AREA
AND HIGH PRESSURE RIDGE EXTENDING ACROSS THE LESSER ANTILLES INTO
THE EASTERN CARIBBEAN...WILL MAINTAIN A DOMINANT WEST TO SOUTHWEST
WIND FLOW ALONG WITH A FAIRLY DRY AND CONVERGENT UPPER LEVEL
PATTERN ACROSS THE REGION THROUGH AT LEAST MONDAY. UPPER TROUGH IS
TO THEN SHIFT EASTWARD ACROSS THE REGION BY THURSDAY AND DURING
THE LATTER PART OF THE WORK WEEK.
&&
.DISCUSSION...THE OVERALL PATTERN CONTINUES TO BE INFLUENCED BY
HIGH PRESSURE NORTH OF THE AREA. EXPECT THE LOCAL PRESSURE GRADIENT
TO TIGHTEN ACROSS THE REGION...AS THE SURFACE HIGH BUILDS NORTH
OF THE AREA BY MID WEEK. THIS WILL CREATE MODERATE TO STRONG TRADE
WINDS. WEAK PERTURBATIONS MOVING WESTWARD IN THE PREVAILING WIND
FLOW WILL HELP TRANSPORT SHALLOW PATCHES OF LOW LEVEL TRADE WIND
MOISTURE ACROSS THE REGION FROM TIME TO TIME. EXPECT ONLY A FEW
PASSING SHOWERS TO AFFECT THE LOCAL WATERS DURING THE MORNING
HOURS...FOLLOWED BY SOME BRIEF SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM DURING THE AFTERNOON MAINLY OVER THE INTERIOR SECTIONS
OF PUERTO RICO. LIMITED OR NO SHOWER ACTIVITY IS EXPECTED OVER THE
VIRGIN ISLANDS TODAY.
LATEST GPS DERIVED IPW AND LAYERED PRECIPITABLE WATER PRODUCTS
SHOWED A GRADUAL DECLINE IN PRECIPITABLE WATER DURING THE PAST 24
HOURS. EXPECT THIS DECREASING TREND TO CONTINUE AT LEAST THROUGH
TUESDAY. EXPECT TROPICAL MOISTURE TO INCREASE ONCE AGAIN BY MID
WEEK AND INTO THE UPCOMING WEEKEND AS A LOW LEVEL CONVERGENCE ZONE
IS FORECAST TO DEVELOP ACROSS THE EASTERN CARIBBEAN...THEN LIFT
NORTHWARD ACROSS THE AREA. THIS ALONG WITH THE PROXIMITY OF THE
UPPER LEVEL TROUGH WILL RESULT IN BETTER CHANCE FOR ENHANCED EARLY
MORNING AND AFTERNOON CONVECTION. IN ADDITION BY LATE FRIDAY INTO
SATURDAY MODEL GUIDANCE ALSO SUGGESTS THAT AN EASTERLY WAVE WILL
ENTER THE EASTERN CARIBBEAN AND MOVE SOUTH OF THE AREA. THIS MAY
ALSO INCREASE THE CHANCES FOR MORE SHOWER ACTIVITY ACROSS THE
REGION. WILL HOWEVER CONTINUE TO MONITOR AND SEE HOW THIS UNFOLDS.
&&
.AVIATION...MOSTLY VFR CONDITIONS EXPECTED AT ALL TAF SITES UNTIL
19/16Z. MVFR AND POSSIBLE BRIEF IFR CONDITIONS WILL REMAIN LIKELY
BETWEEN 19/17Z-18/21Z ALONG THE CORDILLERA CENTRAL AND ACROSS TJMZ
AND TJBQ IN AREAS OF +SHRA/TSRA. MOUNTAINS TOPS MAY BE OBSCURED OVER
WRN INTERIOR OF PR. FOR TAF SITES ACROSS THE NORTHERN LEEWARD
ISLANDS...MAINLY VFR CONDITIONS ARE EXPECTED. TJSJ 19/00Z SOUNDING
INDICATES AND EASTERLY WIND FLOW AT 20 KNOTS OR LESS UP TO 15
KFT...BECOMING WESTERLY AND STRONGER ABOVE 15KFT.
&&
.MARINE...SMALL CRAFT SHOULD EXERCISE CAUTION DUE TO WINDS OF UP TO
19 KNOTS. SEAS ARE EXPECTED TO REMAIN AT 5 FEET OR LESS. THIS GENERAL
PATTERN IN MARINE CONDITIONS IS EXPECTED FOR THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 86 76 / 20 20 20 20
STT 87 77 87 78 / 20 20 20 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
72/09
000
FXCA62 TJSJ 190235
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1035 PM AST SAT MAY 18 2013
.UPDATE...AFTERNOON SHOWERS THAT AFFECTED THE INTERIOR AND WESTERN
SECTIONS OF PR DISSIPATED AROUND SUNSET...LEAVING MOSTLY CLEAR TO
PARTLY CLOUDY SKIES. SATELLITE IMAGERY SHOWS A LINE OF HIGH CLOUDS
MOVING IN BUT LITTLE TO NO LOW CLOUDS. IN ADDITION...TERMINAL
DOPPLER RADAR DOES NOT SHOW PRECIPITATION OVER THE AREA. RELATIVELY
DRY AIR IS EXPECTED TO CONTINUE MOVING IN TONIGHT INTO SUNDAY
MORNING...KEEPING THINGS FAIRLY QUIET OVERNIGHT.
AVAILABLE MOISTURE IS EXPECTED TO GRADUALLY INCREASE ON SUNDAY
INTO MONDAY. MODERATE TO LOCALLY HEAVY SHOWERS AND ISOLATED
THUNDERSTORMS ARE ONCE AGAIN POSSIBLE ACROSS PORTIONS OF THE
INTERIOR AND WESTERN PUERTO RICO ON SUNDAY AFTERNOON...WITH A FEW
SHOWERS ELSEWHERE...MOST LIKELY DUE TO STREAMERS OFF THE ISLANDS
AND EL YUNQUE RAIN FOREST.
THE CURRENT FORECAST PACKAGE IS CONSISTENT WITH THE LATEST
GUIDANCE AND OBSERVATIONS...THEREFORE NO SIGNIFICANT CHANGES WERE
MADE TO THE FORECAST PACKAGE.
&&
.AVIATION...VFR CONDS WILL PREVAIL ALL AREAS UNTIL ARND
19/16Z. SHWRS/TSRA WILL DEVELOP AFT 19/16Z AND CREATE GENERAL
MOUNTAIN OBSCURATIONS IN WRN PR MVFR/LCLY IFR IN SHRA AND LOW CIGS.
ALSO COME MVFR MAY BE SEEN AT TIST BTWN 19/17-22Z DUE TO CLOUD
STREAMERS OFF UPWIND ISLANDS. WINDS ALF E-ESE 5-15 KT UP THROUGH 12
KFT. MAX WINDS WLY 60 KNOTS BTWN 40-48 KFT.
&&
.MARINE...SMAL CRAFT SHOULD EXERCISE CAUTION DUE TO WINDS OF UP TO
19 KNOTS. SEAS ARE EXPECTED TO REMAIN AT 5 FEET OR LESS. THIS
GENERAL PATTERN IN MARINE CONDITIONS IS EXPECTED FOR THE NEXT FEW DAYS.
&&
.PREV DISCUSSION... /ISSUED 247 PM AST SAT MAY 18 2013/
SYNOPSIS...SHORT WAVE TROUGH IS EXPECTED TO REACH PUERTO RICO
AND THE U.S. VIRGIN ISLANDS ON MONDAY. LOCAL PRESSURE GRADIENT
WILL CONTINUE TO TIGHTEN AS SURFACE HIGH BUILDS AND RELOCATES
TO THE NORTH OF THE FORECAST AREA. A BROAD MID TO UPPER LEVEL
TROUGH IS EXPECTED TO EXTEND ACROSS THE WESTERN ATLANTIC INTO
THE CENTRAL CARIBBEAN EARLY NEXT WORK WEEK.
DISCUSSION...AS EXPECTED...SKIES WERE MOSTLY SUNNY ACROSS PUERTO
RICO...CULEBRA AND VIEQUES EARLY THIS MORNING...BECOMING PARTLY
TO VARIABLY CLOUDY DURING THE LATE MORNING AND AFTERNOON HOURS.
ACROSS THE U.S. VIRGIN ISLANDS...PARTLY CLOUDY SKIES PREVAILED
THROUGHOUT THE DAY. TERMINAL DOPPLER RADAR AS WELL AS SATELLITE
IMAGERY INDICATED LIMITED SHOWER ACTIVITY SO FAR.
A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO PREVAIL ACROSS
THE FORECAST AREA AT LEAST THROUGH MID WEEK...WITH PASSING SHOWERS
ACROSS THE EAST COASTAL SECTIONS OF THE ISLANDS DURING THE MORNING
HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE MAINLY
FOCUSED ACROSS WESTERN PUERTO RICO. BY MID WEEK...A BROAD TROUGH
IS FORECAST TO EXTEND FROM THE WESTERN ATLANTIC INTO THE CENTRAL
CARIBBEAN...WITH DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA.
THIS WILL BRING ENOUGH MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS
OVER PUERTO RICO AND U.S. VIRGIN ISLANDS TO RESULT IN A BETTER
CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY.
AVIATION...MVFR CONDS WILL REMAIN POSSIBLE THROUGH 18/21Z ALONG
THE CORDILLERA CENTRAL AND AT TJMZ IN AREAS OF SHRA/TSRA. MTN TOPS
MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR THE NORTHERN LEEWARD
AND USVI ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
MARINE...TRANQUIL SEAS EXPECTED TO PREVAIL FOR THE NEXT SEVERAL
DAYS...WITH SEAS UP TO 5 FEET. EASTERLY TRADE WINDS WILL CONTINUE
TO GRADUALLY INCREASE AS LOCAL PRESSURE GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 86 / 10 20 20 20
STT 76 87 76 87 / 20 20 20 20
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
12/25
000
FXCA62 TJSJ 190235
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1035 PM AST SAT MAY 18 2013
.UPDATE...AFTERNOON SHOWERS THAT AFFECTED THE INTERIOR AND WESTERN
SECTIONS OF PR DISSIPATED AROUND SUNSET...LEAVING MOSTLY CLEAR TO
PARTLY CLOUDY SKIES. SATELLITE IMAGERY SHOWS A LINE OF HIGH CLOUDS
MOVING IN BUT LITTLE TO NO LOW CLOUDS. IN ADDITION...TERMINAL
DOPPLER RADAR DOES NOT SHOW PRECIPITATION OVER THE AREA. RELATIVELY
DRY AIR IS EXPECTED TO CONTINUE MOVING IN TONIGHT INTO SUNDAY
MORNING...KEEPING THINGS FAIRLY QUIET OVERNIGHT.
AVAILABLE MOISTURE IS EXPECTED TO GRADUALLY INCREASE ON SUNDAY
INTO MONDAY. MODERATE TO LOCALLY HEAVY SHOWERS AND ISOLATED
THUNDERSTORMS ARE ONCE AGAIN POSSIBLE ACROSS PORTIONS OF THE
INTERIOR AND WESTERN PUERTO RICO ON SUNDAY AFTERNOON...WITH A FEW
SHOWERS ELSEWHERE...MOST LIKELY DUE TO STREAMERS OFF THE ISLANDS
AND EL YUNQUE RAIN FOREST.
THE CURRENT FORECAST PACKAGE IS CONSISTENT WITH THE LATEST
GUIDANCE AND OBSERVATIONS...THEREFORE NO SIGNIFICANT CHANGES WERE
MADE TO THE FORECAST PACKAGE.
&&
.AVIATION...VFR CONDS WILL PREVAIL ALL AREAS UNTIL ARND
19/16Z. SHWRS/TSRA WILL DEVELOP AFT 19/16Z AND CREATE GENERAL
MOUNTAIN OBSCURATIONS IN WRN PR MVFR/LCLY IFR IN SHRA AND LOW CIGS.
ALSO COME MVFR MAY BE SEEN AT TIST BTWN 19/17-22Z DUE TO CLOUD
STREAMERS OFF UPWIND ISLANDS. WINDS ALF E-ESE 5-15 KT UP THROUGH 12
KFT. MAX WINDS WLY 60 KNOTS BTWN 40-48 KFT.
&&
.MARINE...SMAL CRAFT SHOULD EXERCISE CAUTION DUE TO WINDS OF UP TO
19 KNOTS. SEAS ARE EXPECTED TO REMAIN AT 5 FEET OR LESS. THIS
GENERAL PATTERN IN MARINE CONDITIONS IS EXPECTED FOR THE NEXT FEW DAYS.
&&
.PREV DISCUSSION... /ISSUED 247 PM AST SAT MAY 18 2013/
SYNOPSIS...SHORT WAVE TROUGH IS EXPECTED TO REACH PUERTO RICO
AND THE U.S. VIRGIN ISLANDS ON MONDAY. LOCAL PRESSURE GRADIENT
WILL CONTINUE TO TIGHTEN AS SURFACE HIGH BUILDS AND RELOCATES
TO THE NORTH OF THE FORECAST AREA. A BROAD MID TO UPPER LEVEL
TROUGH IS EXPECTED TO EXTEND ACROSS THE WESTERN ATLANTIC INTO
THE CENTRAL CARIBBEAN EARLY NEXT WORK WEEK.
DISCUSSION...AS EXPECTED...SKIES WERE MOSTLY SUNNY ACROSS PUERTO
RICO...CULEBRA AND VIEQUES EARLY THIS MORNING...BECOMING PARTLY
TO VARIABLY CLOUDY DURING THE LATE MORNING AND AFTERNOON HOURS.
ACROSS THE U.S. VIRGIN ISLANDS...PARTLY CLOUDY SKIES PREVAILED
THROUGHOUT THE DAY. TERMINAL DOPPLER RADAR AS WELL AS SATELLITE
IMAGERY INDICATED LIMITED SHOWER ACTIVITY SO FAR.
A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO PREVAIL ACROSS
THE FORECAST AREA AT LEAST THROUGH MID WEEK...WITH PASSING SHOWERS
ACROSS THE EAST COASTAL SECTIONS OF THE ISLANDS DURING THE MORNING
HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE MAINLY
FOCUSED ACROSS WESTERN PUERTO RICO. BY MID WEEK...A BROAD TROUGH
IS FORECAST TO EXTEND FROM THE WESTERN ATLANTIC INTO THE CENTRAL
CARIBBEAN...WITH DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA.
THIS WILL BRING ENOUGH MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS
OVER PUERTO RICO AND U.S. VIRGIN ISLANDS TO RESULT IN A BETTER
CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY.
AVIATION...MVFR CONDS WILL REMAIN POSSIBLE THROUGH 18/21Z ALONG
THE CORDILLERA CENTRAL AND AT TJMZ IN AREAS OF SHRA/TSRA. MTN TOPS
MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR THE NORTHERN LEEWARD
AND USVI ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
MARINE...TRANQUIL SEAS EXPECTED TO PREVAIL FOR THE NEXT SEVERAL
DAYS...WITH SEAS UP TO 5 FEET. EASTERLY TRADE WINDS WILL CONTINUE
TO GRADUALLY INCREASE AS LOCAL PRESSURE GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 86 / 10 20 20 20
STT 76 87 76 87 / 20 20 20 20
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
12/25
000
FXCA62 TJSJ 181847
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
247 PM AST SAT MAY 18 2013
.SYNOPSIS...SHORT WAVE TROUGH IS EXPECTED TO REACH PUERTO RICO
AND THE U.S. VIRGIN ISLANDS ON MONDAY. LOCAL PRESSURE GRADIENT
WILL CONTINUE TO TIGHTEN AS SURFACE HIGH BUILDS AND RELOCATES
TO THE NORTH OF THE FORECAST AREA. A BROAD MID TO UPPER LEVEL
TROUGH IS EXPECTED TO EXTEND ACROSS THE WESTERN ATLANTIC INTO
THE CENTRAL CARIBBEAN EARLY NEXT WORK WEEK.
&&
.DISCUSSION...AS EXPECTED...SKIES WERE MOSTLY SUNNY ACROSS PUERTO
RICO...CULEBRA AND VIEQUES EARLY THIS MORNING...BECOMING PARTLY
TO VARIABLY CLOUDY DURING THE LATE MORNING AND AFTERNOON HOURS.
ACROSS THE U.S. VIRGIN ISLANDS...PARTLY CLOUDY SKIES PREVAILED
THROUGHOUT THE DAY. TERMINAL DOPPLER RADAR AS WELL AS SATELLITE
IMAGERY INDICATED LIMITED SHOWER ACTIVITY SO FAR.
A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO PREVAIL ACROSS
THE FORECAST AREA AT LEAST THROUGH MID WEEK...WITH PASSING SHOWERS
ACROSS THE EAST COASTAL SECTIONS OF THE ISLANDS DURING THE MORNING
HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE MAINLY
FOCUSED ACROSS WESTERN PUERTO RICO. BY MID WEEK...A BROAD TROUGH
IS FORECAST TO EXTEND FROM THE WESTERN ATLANTIC INTO THE CENTRAL
CARIBBEAN...WITH DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA.
THIS WILL BRING ENOUGH MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS
OVER PUERTO RICO AND U.S. VIRGIN ISLANDS TO RESULT IN A BETTER
CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY.
&&
.AVIATION...MVFR CONDS WILL REMAIN POSSIBLE THROUGH 18/21Z ALONG
THE CORDILLERA CENTRAL AND AT TJMZ IN AREAS OF SHRA/TSRA. MTN TOPS
MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR THE NORTHERN LEEWARD
AND USVI ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
&&
.MARINE...TRANQUIL SEAS EXPECTED TO PREVAIL FOR THE NEXT SEVERAL
DAYS...WITH SEAS UP TO 5 FEET. EASTERLY TRADE WINDS WILL CONTINUE
TO GRADUALLY INCREASE AS LOCAL PRESSURE GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 86 / 10 20 20 20
STT 76 87 76 87 / 20 20 20 20
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
10/23
000
FXCA62 TJSJ 181847
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
247 PM AST SAT MAY 18 2013
.SYNOPSIS...SHORT WAVE TROUGH IS EXPECTED TO REACH PUERTO RICO
AND THE U.S. VIRGIN ISLANDS ON MONDAY. LOCAL PRESSURE GRADIENT
WILL CONTINUE TO TIGHTEN AS SURFACE HIGH BUILDS AND RELOCATES
TO THE NORTH OF THE FORECAST AREA. A BROAD MID TO UPPER LEVEL
TROUGH IS EXPECTED TO EXTEND ACROSS THE WESTERN ATLANTIC INTO
THE CENTRAL CARIBBEAN EARLY NEXT WORK WEEK.
&&
.DISCUSSION...AS EXPECTED...SKIES WERE MOSTLY SUNNY ACROSS PUERTO
RICO...CULEBRA AND VIEQUES EARLY THIS MORNING...BECOMING PARTLY
TO VARIABLY CLOUDY DURING THE LATE MORNING AND AFTERNOON HOURS.
ACROSS THE U.S. VIRGIN ISLANDS...PARTLY CLOUDY SKIES PREVAILED
THROUGHOUT THE DAY. TERMINAL DOPPLER RADAR AS WELL AS SATELLITE
IMAGERY INDICATED LIMITED SHOWER ACTIVITY SO FAR.
A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO PREVAIL ACROSS
THE FORECAST AREA AT LEAST THROUGH MID WEEK...WITH PASSING SHOWERS
ACROSS THE EAST COASTAL SECTIONS OF THE ISLANDS DURING THE MORNING
HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE MAINLY
FOCUSED ACROSS WESTERN PUERTO RICO. BY MID WEEK...A BROAD TROUGH
IS FORECAST TO EXTEND FROM THE WESTERN ATLANTIC INTO THE CENTRAL
CARIBBEAN...WITH DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA.
THIS WILL BRING ENOUGH MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS
OVER PUERTO RICO AND U.S. VIRGIN ISLANDS TO RESULT IN A BETTER
CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY.
&&
.AVIATION...MVFR CONDS WILL REMAIN POSSIBLE THROUGH 18/21Z ALONG
THE CORDILLERA CENTRAL AND AT TJMZ IN AREAS OF SHRA/TSRA. MTN TOPS
MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR THE NORTHERN LEEWARD
AND USVI ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
&&
.MARINE...TRANQUIL SEAS EXPECTED TO PREVAIL FOR THE NEXT SEVERAL
DAYS...WITH SEAS UP TO 5 FEET. EASTERLY TRADE WINDS WILL CONTINUE
TO GRADUALLY INCREASE AS LOCAL PRESSURE GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 86 / 10 20 20 20
STT 76 87 76 87 / 20 20 20 20
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
10/23
000
FXCA62 TJSJ 181847
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
247 PM AST SAT MAY 18 2013
.SYNOPSIS...SHORT WAVE TROUGH IS EXPECTED TO REACH PUERTO RICO
AND THE U.S. VIRGIN ISLANDS ON MONDAY. LOCAL PRESSURE GRADIENT
WILL CONTINUE TO TIGHTEN AS SURFACE HIGH BUILDS AND RELOCATES
TO THE NORTH OF THE FORECAST AREA. A BROAD MID TO UPPER LEVEL
TROUGH IS EXPECTED TO EXTEND ACROSS THE WESTERN ATLANTIC INTO
THE CENTRAL CARIBBEAN EARLY NEXT WORK WEEK.
&&
.DISCUSSION...AS EXPECTED...SKIES WERE MOSTLY SUNNY ACROSS PUERTO
RICO...CULEBRA AND VIEQUES EARLY THIS MORNING...BECOMING PARTLY
TO VARIABLY CLOUDY DURING THE LATE MORNING AND AFTERNOON HOURS.
ACROSS THE U.S. VIRGIN ISLANDS...PARTLY CLOUDY SKIES PREVAILED
THROUGHOUT THE DAY. TERMINAL DOPPLER RADAR AS WELL AS SATELLITE
IMAGERY INDICATED LIMITED SHOWER ACTIVITY SO FAR.
A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO PREVAIL ACROSS
THE FORECAST AREA AT LEAST THROUGH MID WEEK...WITH PASSING SHOWERS
ACROSS THE EAST COASTAL SECTIONS OF THE ISLANDS DURING THE MORNING
HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE MAINLY
FOCUSED ACROSS WESTERN PUERTO RICO. BY MID WEEK...A BROAD TROUGH
IS FORECAST TO EXTEND FROM THE WESTERN ATLANTIC INTO THE CENTRAL
CARIBBEAN...WITH DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA.
THIS WILL BRING ENOUGH MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS
OVER PUERTO RICO AND U.S. VIRGIN ISLANDS TO RESULT IN A BETTER
CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY.
&&
.AVIATION...MVFR CONDS WILL REMAIN POSSIBLE THROUGH 18/21Z ALONG
THE CORDILLERA CENTRAL AND AT TJMZ IN AREAS OF SHRA/TSRA. MTN TOPS
MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR THE NORTHERN LEEWARD
AND USVI ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
&&
.MARINE...TRANQUIL SEAS EXPECTED TO PREVAIL FOR THE NEXT SEVERAL
DAYS...WITH SEAS UP TO 5 FEET. EASTERLY TRADE WINDS WILL CONTINUE
TO GRADUALLY INCREASE AS LOCAL PRESSURE GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 86 / 10 20 20 20
STT 76 87 76 87 / 20 20 20 20
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
10/23
000
FXCA62 TJSJ 181847
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
247 PM AST SAT MAY 18 2013
.SYNOPSIS...SHORT WAVE TROUGH IS EXPECTED TO REACH PUERTO RICO
AND THE U.S. VIRGIN ISLANDS ON MONDAY. LOCAL PRESSURE GRADIENT
WILL CONTINUE TO TIGHTEN AS SURFACE HIGH BUILDS AND RELOCATES
TO THE NORTH OF THE FORECAST AREA. A BROAD MID TO UPPER LEVEL
TROUGH IS EXPECTED TO EXTEND ACROSS THE WESTERN ATLANTIC INTO
THE CENTRAL CARIBBEAN EARLY NEXT WORK WEEK.
&&
.DISCUSSION...AS EXPECTED...SKIES WERE MOSTLY SUNNY ACROSS PUERTO
RICO...CULEBRA AND VIEQUES EARLY THIS MORNING...BECOMING PARTLY
TO VARIABLY CLOUDY DURING THE LATE MORNING AND AFTERNOON HOURS.
ACROSS THE U.S. VIRGIN ISLANDS...PARTLY CLOUDY SKIES PREVAILED
THROUGHOUT THE DAY. TERMINAL DOPPLER RADAR AS WELL AS SATELLITE
IMAGERY INDICATED LIMITED SHOWER ACTIVITY SO FAR.
A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO PREVAIL ACROSS
THE FORECAST AREA AT LEAST THROUGH MID WEEK...WITH PASSING SHOWERS
ACROSS THE EAST COASTAL SECTIONS OF THE ISLANDS DURING THE MORNING
HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE MAINLY
FOCUSED ACROSS WESTERN PUERTO RICO. BY MID WEEK...A BROAD TROUGH
IS FORECAST TO EXTEND FROM THE WESTERN ATLANTIC INTO THE CENTRAL
CARIBBEAN...WITH DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA.
THIS WILL BRING ENOUGH MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS
OVER PUERTO RICO AND U.S. VIRGIN ISLANDS TO RESULT IN A BETTER
CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY.
&&
.AVIATION...MVFR CONDS WILL REMAIN POSSIBLE THROUGH 18/21Z ALONG
THE CORDILLERA CENTRAL AND AT TJMZ IN AREAS OF SHRA/TSRA. MTN TOPS
MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR THE NORTHERN LEEWARD
AND USVI ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
&&
.MARINE...TRANQUIL SEAS EXPECTED TO PREVAIL FOR THE NEXT SEVERAL
DAYS...WITH SEAS UP TO 5 FEET. EASTERLY TRADE WINDS WILL CONTINUE
TO GRADUALLY INCREASE AS LOCAL PRESSURE GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 86 / 10 20 20 20
STT 76 87 76 87 / 20 20 20 20
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
10/23
000
FXCA62 TJSJ 181628
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1228 PM AST SAT MAY 18 2013
.UPDATE...AT THIS MOMENT SATELLITE IMAGES ARE SHOWING CU LINES
DEVELOPING OVER THE LOCAL ISLANDS AND ACROSS THE CORDILLERA
CENTRAL. NO CHANGES TO THE PREVIOUS FORECAST PACKAGE...STILL
EXPECTING SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN PORTIONS OF
PUERTO RICO.
&&
.DISCUSSION...SEAS MAINLY 5 FEET OR LESS TODAY. EASTERLY TRADE
WINDS WILL GRADUALLY INCREASE BY MID WEEK AS PREVIOUSLY MENTIONED
SURFACE PRESSURE GRADIENT TIGHTENS.
&&
.AVIATION...MVFR/PSBL BRIEF IFR CONDS WILL REMAIN LIKELY BETWEEN
18/17Z-18/21Z ALONG THE CORDILLERA CENTRAL AND ACROSS TJMZ IN
AREAS OF +SHRA/TSRA. MTN TOPS MAY BE OBSCURED OVER WRN INTERIOR OF
PR. FOR THE NORTHERN LEEWARD ISLANDS...MAINLY VFR CONDS ARE
EXPECTED.
&&
.MARINE...
&&
.PREV DISCUSSION... /ISSUED 510 AM AST SAT MAY 18 2013/
SYNOPSIS...STRENGTHENING SURFACE HIGH PRESSURE ACROSS THE NORTH
CENTRAL ATLANTIC AND JUST NORTH OF THE REGION WILL MAINTAIN A
DOMINANT EASTERLY TRADE WIND FLOW ACROSS THE NORTHEASTERN CARIBBEAN
FOR THE NEXT SEVERAL DAYS. MID TO UPPER LEVEL TROUGH CONTINUED TO
SHIFT EAST NORTHEAST OF AREA. MEANWHILE MID TO UPPER RIDGE EXTENDS
NORTHWARDS ACROSS THE REGION FROM THE CARIBBEAN BASIN. THIS OVERALL
PATTERN WILL MAINTAIN PREVAILING UPPER LEVEL WESTERLIES THROUGH AT
LEAST THE MIDDLE OF THE UPCOMING WEEK.
DISCUSSION...PREVIOUS TJSJ 19/00Z UPPER AIR SOUNDING AS WELL AS
SAT AND GPS DERIVED PWAT/IPW ANALYSIS PRODUCTS ALL SUGGEST A
GRADUAL DYING TREND DURING THE PAST 24 HOURS WITH ONLY SHALLOW
PATCHES OF LOW LEVEL MOISTURE MOVING ACROSS THE REGIONAL WATERS.
LATEST SATELLITE IMAGERY ALSO SHOWED LESSER CLOUD COVER/MOISTURE
COMPARED TO RECENT DAYS...WITH SUBTROPICAL JET AXIS NOW RELOCATED
EAST OF THE REGION AND OVER THE LESSER ANTILLES. THIS IS PLACED
THE FORECAST AREAS IN A FAIRLY DRY AND SUBSIDENT PATTERN ALOFT.
EXPECT FAIR AMOUNTS OF SUNSHINE TODAY WITH SOME DIURNALLY INDUCED
SHOWER DEVELOPMENT POSSIBLE MAINLY ACROSS PARTS OF THE CENTRAL
AND WEST INTERIOR SECTIONS OF PUERTO RICO. ACTIVITY SHOULD HOWEVER
BE OF SHORT DURATION AND NOT WIDESPREAD AMOUNTS OF RAINFALL. BY
LATE SUNDAY AND INTO MONDAY A SECONDARY SHORT WAVE SHOULD MOVE
JUST NORTH OF THE REGION. HOWEVER NO SIGNIFICANT AMOUNTS OF MOISTURE
ADVECTION IS APPARENT AT THIS TIME...AS THE UPPER LEVEL WINDS CONTINUE
TO SHEAR THE CONVECTION ACROSS THE TROPICAL ATLANTIC AND MAINTAIN
MOST OF TROPICAL MOISTURE SOUTH OF THE REGION.
BY MID WEEK HOWEVER AND FOR THE REST OF THE UPCOMING WEEK LOOK
FOR INCREASING MOISTURE AS LONG WAVE TROUGH WEST OF THE REGION
SHOULD BECOME SLIGHTLY AMPLIFIED WEST OF THE AREA. THIS SHOULD
LIFT ADDITIONAL TROPICAL MOISTURE NORTHWARDS ACROSS THE REGION.
LATEST GFS MODEL CONTINUED TO SUGGEST PWAT VALUES TO INCREASE TO
TWO INCHES OR MORE BY THURSDAY AND INTO THE FOLLOWING WEEKEND. THE
COMBINATION OF THE AMPLIFYING UPPER TROUGH AND INCREASING MOISTURE
WILL MAKE CONDITIONS MORE FAVORABLE AND UNSTABLE...THUS RESULTING IN
BETTER CHANCE FOR ENHANCED CONVECTIVE DEVELOPMENT DURING THE LATTER
PART OF THE WEEK.
AVIATION...MOSTLY VFR COND ARE EXPECTED AT ALL TAF SITES UNTIL
18/16Z. MVFR/PSBL BRIEF IFR CONDS WILL REMAIN LIKELY BETWEEN
18/17Z-18/21Z ALONG THE CORDILLERA CENTRAL AND ACROSS TJMZ IN AREAS
OF +SHRA/TSRA. MTN TOPS MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR
THE NORTHERN LEEWARD ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
PREVIOUS 18/ 00Z TJSJ SOUNDING INDICATES MAINLY EAST WINDS AT 20
KNOTS OR LESS UP TO 3 KFT...BECOMING LIGHT AND VARIABLE BTW 3-20KFT
AND THEN NORTHWESTERLY AND STRONGER ALOFT.
MARINE...FAIRLY TRANQUIL SEAS OVERALL FOR THE NEXT SEVERAL DAYS...WITH
SEAS MAINLY 5 FEET OR LESS TODAY. EASTERLY TRADE WINDS WILL GRADUALLY
INCREASE BY MID WEEK AS PREVIOUSLY MENTIONED SURFACE PRESSURE
GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 87 77 / 20 20 20 20
STT 86 76 87 78 / 10 30 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
10/23
000
FXCA62 TJSJ 181628
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1228 PM AST SAT MAY 18 2013
.UPDATE...AT THIS MOMENT SATELLITE IMAGES ARE SHOWING CU LINES
DEVELOPING OVER THE LOCAL ISLANDS AND ACROSS THE CORDILLERA
CENTRAL. NO CHANGES TO THE PREVIOUS FORECAST PACKAGE...STILL
EXPECTING SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN PORTIONS OF
PUERTO RICO.
&&
.DISCUSSION...SEAS MAINLY 5 FEET OR LESS TODAY. EASTERLY TRADE
WINDS WILL GRADUALLY INCREASE BY MID WEEK AS PREVIOUSLY MENTIONED
SURFACE PRESSURE GRADIENT TIGHTENS.
&&
.AVIATION...MVFR/PSBL BRIEF IFR CONDS WILL REMAIN LIKELY BETWEEN
18/17Z-18/21Z ALONG THE CORDILLERA CENTRAL AND ACROSS TJMZ IN
AREAS OF +SHRA/TSRA. MTN TOPS MAY BE OBSCURED OVER WRN INTERIOR OF
PR. FOR THE NORTHERN LEEWARD ISLANDS...MAINLY VFR CONDS ARE
EXPECTED.
&&
.MARINE...
&&
.PREV DISCUSSION... /ISSUED 510 AM AST SAT MAY 18 2013/
SYNOPSIS...STRENGTHENING SURFACE HIGH PRESSURE ACROSS THE NORTH
CENTRAL ATLANTIC AND JUST NORTH OF THE REGION WILL MAINTAIN A
DOMINANT EASTERLY TRADE WIND FLOW ACROSS THE NORTHEASTERN CARIBBEAN
FOR THE NEXT SEVERAL DAYS. MID TO UPPER LEVEL TROUGH CONTINUED TO
SHIFT EAST NORTHEAST OF AREA. MEANWHILE MID TO UPPER RIDGE EXTENDS
NORTHWARDS ACROSS THE REGION FROM THE CARIBBEAN BASIN. THIS OVERALL
PATTERN WILL MAINTAIN PREVAILING UPPER LEVEL WESTERLIES THROUGH AT
LEAST THE MIDDLE OF THE UPCOMING WEEK.
DISCUSSION...PREVIOUS TJSJ 19/00Z UPPER AIR SOUNDING AS WELL AS
SAT AND GPS DERIVED PWAT/IPW ANALYSIS PRODUCTS ALL SUGGEST A
GRADUAL DYING TREND DURING THE PAST 24 HOURS WITH ONLY SHALLOW
PATCHES OF LOW LEVEL MOISTURE MOVING ACROSS THE REGIONAL WATERS.
LATEST SATELLITE IMAGERY ALSO SHOWED LESSER CLOUD COVER/MOISTURE
COMPARED TO RECENT DAYS...WITH SUBTROPICAL JET AXIS NOW RELOCATED
EAST OF THE REGION AND OVER THE LESSER ANTILLES. THIS IS PLACED
THE FORECAST AREAS IN A FAIRLY DRY AND SUBSIDENT PATTERN ALOFT.
EXPECT FAIR AMOUNTS OF SUNSHINE TODAY WITH SOME DIURNALLY INDUCED
SHOWER DEVELOPMENT POSSIBLE MAINLY ACROSS PARTS OF THE CENTRAL
AND WEST INTERIOR SECTIONS OF PUERTO RICO. ACTIVITY SHOULD HOWEVER
BE OF SHORT DURATION AND NOT WIDESPREAD AMOUNTS OF RAINFALL. BY
LATE SUNDAY AND INTO MONDAY A SECONDARY SHORT WAVE SHOULD MOVE
JUST NORTH OF THE REGION. HOWEVER NO SIGNIFICANT AMOUNTS OF MOISTURE
ADVECTION IS APPARENT AT THIS TIME...AS THE UPPER LEVEL WINDS CONTINUE
TO SHEAR THE CONVECTION ACROSS THE TROPICAL ATLANTIC AND MAINTAIN
MOST OF TROPICAL MOISTURE SOUTH OF THE REGION.
BY MID WEEK HOWEVER AND FOR THE REST OF THE UPCOMING WEEK LOOK
FOR INCREASING MOISTURE AS LONG WAVE TROUGH WEST OF THE REGION
SHOULD BECOME SLIGHTLY AMPLIFIED WEST OF THE AREA. THIS SHOULD
LIFT ADDITIONAL TROPICAL MOISTURE NORTHWARDS ACROSS THE REGION.
LATEST GFS MODEL CONTINUED TO SUGGEST PWAT VALUES TO INCREASE TO
TWO INCHES OR MORE BY THURSDAY AND INTO THE FOLLOWING WEEKEND. THE
COMBINATION OF THE AMPLIFYING UPPER TROUGH AND INCREASING MOISTURE
WILL MAKE CONDITIONS MORE FAVORABLE AND UNSTABLE...THUS RESULTING IN
BETTER CHANCE FOR ENHANCED CONVECTIVE DEVELOPMENT DURING THE LATTER
PART OF THE WEEK.
AVIATION...MOSTLY VFR COND ARE EXPECTED AT ALL TAF SITES UNTIL
18/16Z. MVFR/PSBL BRIEF IFR CONDS WILL REMAIN LIKELY BETWEEN
18/17Z-18/21Z ALONG THE CORDILLERA CENTRAL AND ACROSS TJMZ IN AREAS
OF +SHRA/TSRA. MTN TOPS MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR
THE NORTHERN LEEWARD ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
PREVIOUS 18/ 00Z TJSJ SOUNDING INDICATES MAINLY EAST WINDS AT 20
KNOTS OR LESS UP TO 3 KFT...BECOMING LIGHT AND VARIABLE BTW 3-20KFT
AND THEN NORTHWESTERLY AND STRONGER ALOFT.
MARINE...FAIRLY TRANQUIL SEAS OVERALL FOR THE NEXT SEVERAL DAYS...WITH
SEAS MAINLY 5 FEET OR LESS TODAY. EASTERLY TRADE WINDS WILL GRADUALLY
INCREASE BY MID WEEK AS PREVIOUSLY MENTIONED SURFACE PRESSURE
GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 87 77 / 20 20 20 20
STT 86 76 87 78 / 10 30 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
10/23
000
FXCA62 TJSJ 180910
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
510 AM AST SAT MAY 18 2013
.SYNOPSIS...STRENGTHENING SURFACE HIGH PRESSURE ACROSS THE NORTH
CENTRAL ATLANTIC AND JUST NORTH OF THE REGION WILL MAINTAIN A
DOMINANT EASTERLY TRADE WIND FLOW ACROSS THE NORTHEASTERN CARIBBEAN
FOR THE NEXT SEVERAL DAYS. MID TO UPPER LEVEL TROUGH CONTINUED TO
SHIFT EAST NORTHEAST OF AREA. MEANWHILE MID TO UPPER RIDGE EXTENDS
NORTHWARDS ACROSS THE REGION FROM THE CARIBBEAN BASIN. THIS OVERALL
PATTERN WILL MAINTAIN PREVAILING UPPER LEVEL WESTERLIES THROUGH AT
LEAST THE MIDDLE OF THE UPCOMING WEEK.
&&
.DISCUSSION...PREVIOUS TJSJ 19/00Z UPPER AIR SOUNDING AS WELL AS
SAT AND GPS DERIVED PWAT/IPW ANALYSIS PRODUCTS ALL SUGGEST A
GRADUAL DYING TREND DURING THE PAST 24 HOURS WITH ONLY SHALLOW
PATCHES OF LOW LEVEL MOISTURE MOVING ACROSS THE REGIONAL WATERS.
LATEST SATELLITE IMAGERY ALSO SHOWED LESSER CLOUD COVER/MOISTURE
COMPARED TO RECENT DAYS...WITH SUBTROPICAL JET AXIS NOW RELOCATED
EAST OF THE REGION AND OVER THE LESSER ANTILLES. THIS IS PLACED
THE FORECAST AREAS IN A FAIRLY DRY AND SUBSIDENT PATTERN ALOFT.
EXPECT FAIR AMOUNTS OF SUNSHINE TODAY WITH SOME DIURNALLY INDUCED
SHOWER DEVELOPMENT POSSIBLE MAINLY ACROSS PARTS OF THE CENTRAL
AND WEST INTERIOR SECTIONS OF PUERTO RICO. ACTIVITY SHOULD HOWEVER
BE OF SHORT DURATION AND NOT WIDESPREAD AMOUNTS OF RAINFALL. BY
LATE SUNDAY AND INTO MONDAY A SECONDARY SHORT WAVE SHOULD MOVE
JUST NORTH OF THE REGION. HOWEVER NO SIGNIFICANT AMOUNTS OF MOISTURE
ADVECTION IS APPARENT AT THIS TIME...AS THE UPPER LEVEL WINDS CONTINUE
TO SHEAR THE CONVECTION ACROSS THE TROPICAL ATLANTIC AND MAINTAIN
MOST OF TROPICAL MOISTURE SOUTH OF THE REGION.
BY MID WEEK HOWEVER AND FOR THE REST OF THE UPCOMING WEEK LOOK
FOR INCREASING MOISTURE AS LONG WAVE TROUGH WEST OF THE REGION
SHOULD BECOME SLIGHTLY AMPLIFIED WEST OF THE AREA. THIS SHOULD
LIFT ADDITIONAL TROPICAL MOISTURE NORTHWARDS ACROSS THE REGION.
LATEST GFS MODEL CONTINUED TO SUGGEST PWAT VALUES TO INCREASE TO
TWO INCHES OR MORE BY THURSDAY AND INTO THE FOLLOWING WEEKEND. THE
COMBINATION OF THE AMPLIFYING UPPER TROUGH AND INCREASING MOISTURE
WILL MAKE CONDITIONS MORE FAVORABLE AND UNSTABLE...THUS RESULTING IN
BETTER CHANCE FOR ENHANCED CONVECTIVE DEVELOPMENT DURING THE LATTER
PART OF THE WEEK.
&&
.AVIATION...MOSTLY VFR COND ARE EXPECTED AT ALL TAF SITES UNTIL
18/16Z. MVFR/PSBL BRIEF IFR CONDS WILL REMAIN LIKELY BETWEEN
18/17Z-18/21Z ALONG THE CORDILLERA CENTRAL AND ACROSS TJMZ IN AREAS
OF +SHRA/TSRA. MTN TOPS MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR
THE NORTHERN LEEWARD ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
PREVIOUS 18/ 00Z TJSJ SOUNDING INDICATES MAINLY EAST WINDS AT 20
KNOTS OR LESS UP TO 3 KFT...BECOMING LIGHT AND VARIABLE BTW 3-20KFT
AND THEN NORTHWESTERLY AND STRONGER ALOFT.
&&
.MARINE...FAIRLY TRANQUIL SEAS OVERALL FOR THE NEXT SEVERAL DAYS...WITH
SEAS MAINLY 5 FEET OR LESS TODAY. EASTERLY TRADE WINDS WILL GRADUALLY
INCREASE BY MID WEEK AS PREVIOUSLY MENTIONED SURFACE PRESSURE
GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 87 77 / 20 20 20 20
STT 86 76 87 78 / 10 30 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
72/09
000
FXCA62 TJSJ 180910
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
510 AM AST SAT MAY 18 2013
.SYNOPSIS...STRENGTHENING SURFACE HIGH PRESSURE ACROSS THE NORTH
CENTRAL ATLANTIC AND JUST NORTH OF THE REGION WILL MAINTAIN A
DOMINANT EASTERLY TRADE WIND FLOW ACROSS THE NORTHEASTERN CARIBBEAN
FOR THE NEXT SEVERAL DAYS. MID TO UPPER LEVEL TROUGH CONTINUED TO
SHIFT EAST NORTHEAST OF AREA. MEANWHILE MID TO UPPER RIDGE EXTENDS
NORTHWARDS ACROSS THE REGION FROM THE CARIBBEAN BASIN. THIS OVERALL
PATTERN WILL MAINTAIN PREVAILING UPPER LEVEL WESTERLIES THROUGH AT
LEAST THE MIDDLE OF THE UPCOMING WEEK.
&&
.DISCUSSION...PREVIOUS TJSJ 19/00Z UPPER AIR SOUNDING AS WELL AS
SAT AND GPS DERIVED PWAT/IPW ANALYSIS PRODUCTS ALL SUGGEST A
GRADUAL DYING TREND DURING THE PAST 24 HOURS WITH ONLY SHALLOW
PATCHES OF LOW LEVEL MOISTURE MOVING ACROSS THE REGIONAL WATERS.
LATEST SATELLITE IMAGERY ALSO SHOWED LESSER CLOUD COVER/MOISTURE
COMPARED TO RECENT DAYS...WITH SUBTROPICAL JET AXIS NOW RELOCATED
EAST OF THE REGION AND OVER THE LESSER ANTILLES. THIS IS PLACED
THE FORECAST AREAS IN A FAIRLY DRY AND SUBSIDENT PATTERN ALOFT.
EXPECT FAIR AMOUNTS OF SUNSHINE TODAY WITH SOME DIURNALLY INDUCED
SHOWER DEVELOPMENT POSSIBLE MAINLY ACROSS PARTS OF THE CENTRAL
AND WEST INTERIOR SECTIONS OF PUERTO RICO. ACTIVITY SHOULD HOWEVER
BE OF SHORT DURATION AND NOT WIDESPREAD AMOUNTS OF RAINFALL. BY
LATE SUNDAY AND INTO MONDAY A SECONDARY SHORT WAVE SHOULD MOVE
JUST NORTH OF THE REGION. HOWEVER NO SIGNIFICANT AMOUNTS OF MOISTURE
ADVECTION IS APPARENT AT THIS TIME...AS THE UPPER LEVEL WINDS CONTINUE
TO SHEAR THE CONVECTION ACROSS THE TROPICAL ATLANTIC AND MAINTAIN
MOST OF TROPICAL MOISTURE SOUTH OF THE REGION.
BY MID WEEK HOWEVER AND FOR THE REST OF THE UPCOMING WEEK LOOK
FOR INCREASING MOISTURE AS LONG WAVE TROUGH WEST OF THE REGION
SHOULD BECOME SLIGHTLY AMPLIFIED WEST OF THE AREA. THIS SHOULD
LIFT ADDITIONAL TROPICAL MOISTURE NORTHWARDS ACROSS THE REGION.
LATEST GFS MODEL CONTINUED TO SUGGEST PWAT VALUES TO INCREASE TO
TWO INCHES OR MORE BY THURSDAY AND INTO THE FOLLOWING WEEKEND. THE
COMBINATION OF THE AMPLIFYING UPPER TROUGH AND INCREASING MOISTURE
WILL MAKE CONDITIONS MORE FAVORABLE AND UNSTABLE...THUS RESULTING IN
BETTER CHANCE FOR ENHANCED CONVECTIVE DEVELOPMENT DURING THE LATTER
PART OF THE WEEK.
&&
.AVIATION...MOSTLY VFR COND ARE EXPECTED AT ALL TAF SITES UNTIL
18/16Z. MVFR/PSBL BRIEF IFR CONDS WILL REMAIN LIKELY BETWEEN
18/17Z-18/21Z ALONG THE CORDILLERA CENTRAL AND ACROSS TJMZ IN AREAS
OF +SHRA/TSRA. MTN TOPS MAY BE OBSCURED OVER WRN INTERIOR OF PR. FOR
THE NORTHERN LEEWARD ISLANDS...MAINLY VFR CONDS ARE EXPECTED.
PREVIOUS 18/ 00Z TJSJ SOUNDING INDICATES MAINLY EAST WINDS AT 20
KNOTS OR LESS UP TO 3 KFT...BECOMING LIGHT AND VARIABLE BTW 3-20KFT
AND THEN NORTHWESTERLY AND STRONGER ALOFT.
&&
.MARINE...FAIRLY TRANQUIL SEAS OVERALL FOR THE NEXT SEVERAL DAYS...WITH
SEAS MAINLY 5 FEET OR LESS TODAY. EASTERLY TRADE WINDS WILL GRADUALLY
INCREASE BY MID WEEK AS PREVIOUSLY MENTIONED SURFACE PRESSURE
GRADIENT TIGHTENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 87 77 / 20 20 20 20
STT 86 76 87 78 / 10 30 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
72/09
000
FXCA62 TJSJ 180050
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
850 PM AST FRI MAY 17 2013
.UPDATE...SHOWERS LINGERED OVER SOUTHWEST PUERTO RICO...BUT WILL BE
MOVING OFFSHORE BY ABOUT 10 PM AST. OTHERWISE PREVIOUS FORECAST
HOLDS. DRIER AIR IS JUST EAST OF PUERTO RICO AND WILL MOVE OVER
THE AREA DURING THE MORNING. ALSO STILL EXPECTING AFTERNOON
CONVECTION IN THE WEST AND SOUTHWEST...SHOULD NOT LAST AS LONG AS
TODAY HOWEVER. WILL NOT UPDATE ZONE PACKAGE.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES UNTIL
18/16Z. MVFR/IFR CONDS ARE LIKELY BTWN 18/17Z-21Z ALONG THE
CORDILLERA CENTRAL AND TJMZ IN AREAS OF +SHRA/TSRA. MOUNTAINS WILL
BE OBSCURED OVER WESTERN INTERIOR OF PR. FOR THE LEEWARD
ISLANDS...VFR CONDITIONS ARE EXPECTED. 00Z TJSJ SOUNDING INDICATES
MAINLY EAST WINDS AT 18 KNOTS OR LESS UP TO 2 KFT.
&&
.MARINE...SEAS STILL HOLDING AT NO MORE THAN 5 FEET...EVEN AT BUOY
41043. WINDS WILL INCREASE NEXT WEEK.
&&
.PREV DISCUSSION... /ISSUED 256 PM AST FRI MAY 17 2013/
SYNOPSIS...A MID TO UPPER LEVEL TROUGH ACROSS THE CENTRAL ATLANTIC
INTO THE EASTERN CARIBBEAN WILL CONTINUE TO MOVE EAST AND AWAY FROM
THE LOCAL ISLANDS. LOCAL PRESSURE GRADIENT WILL TIGHTEN AS SURFACE
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA. A
BETTER CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED NEXT
WORK WEEK.
DISCUSSION...A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO
PREVAIL TONIGHT INTO THE WEEKEND AS TROUGH ALOFT CONTINUES TO MOVE
AWAY FROM THE LOCAL AREA. AS AFOREMENTIONED TROUGH MOVES TO THE
EAST...A WEAK MID LEVEL RIDGE WILL CONTINUE TO BUILD FROM THE
WEST. AT LOW LEVELS...LOCAL PRESSURE GRADIENT WILL TIGHTEN AS
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA.
AS RESULT...FOR THE NEXT TWO DAYS OR SO...UNDER THE PREVAILING
WIND FLOW...EXPECT PASSING SHOWERS EMBEDDED IN THE TRADES ACROSS
THE EAST COASTAL SECTIONS OF THE ISLANDS ESPECIALLY DURING THE
MORNING HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE
MAINLY FOCUSED ACROSS WESTERN PUERTO RICO DUE TO DIURNAL HEATING
AND LOCAL EFFECTS.
FOR THE UPCOMING WORK WEEK...A HIGHER AMPLITUDE TROUGH IS FORECAST
TO EXTEND FROM THE BAHAMAS INTO THE WESTERN CARIBBEAN...WITH
DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA. THIS WILL BRING
DEEP MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS OVER PUERTO RICO
AND U.S. VIRGIN ISLANDS...RESULTING IN CLOUDY AND WET CONDITIONS
WITH A GOOD CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY ESPECIALLY
THE MIDDLE/LATTER PART OF NEXT WEEK.
AVIATION...VFR CONDITIONS EXPECTED ACROSS THE LOCAL TERMINALS
THROUGH THE FORECAST PERIOD WITH THE EXCEPTION OF TJMZ AND THE
VICINITY OF TJBQ WHERE SHRA/TSRA MAY CAUSE MVFR/IFR CONDITIONS UNTIL
AROUND 18/22Z. EASTERLY WINDS WITH SEA BREEZE VARIATIONS AT AROUND
10 TO 15 KTS GUSTING TO 25KTS UNTIL 18/00Z...BECOMING LIGHTER
THEREAFTER.
MARINE...LOCAL PRESSURE GRADIENT WILL TIGHTEN DURING THE WEEKEND
AS SURFACE HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST
AREA. SEAS UP TO 5 FEET AND WINDS UP TO 21 KNOTS EXPECTED FOR
THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 87 / 10 20 20 20
STT 76 88 76 88 / 10 10 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
13/12
000
FXCA62 TJSJ 180050
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
850 PM AST FRI MAY 17 2013
.UPDATE...SHOWERS LINGERED OVER SOUTHWEST PUERTO RICO...BUT WILL BE
MOVING OFFSHORE BY ABOUT 10 PM AST. OTHERWISE PREVIOUS FORECAST
HOLDS. DRIER AIR IS JUST EAST OF PUERTO RICO AND WILL MOVE OVER
THE AREA DURING THE MORNING. ALSO STILL EXPECTING AFTERNOON
CONVECTION IN THE WEST AND SOUTHWEST...SHOULD NOT LAST AS LONG AS
TODAY HOWEVER. WILL NOT UPDATE ZONE PACKAGE.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES UNTIL
18/16Z. MVFR/IFR CONDS ARE LIKELY BTWN 18/17Z-21Z ALONG THE
CORDILLERA CENTRAL AND TJMZ IN AREAS OF +SHRA/TSRA. MOUNTAINS WILL
BE OBSCURED OVER WESTERN INTERIOR OF PR. FOR THE LEEWARD
ISLANDS...VFR CONDITIONS ARE EXPECTED. 00Z TJSJ SOUNDING INDICATES
MAINLY EAST WINDS AT 18 KNOTS OR LESS UP TO 2 KFT.
&&
.MARINE...SEAS STILL HOLDING AT NO MORE THAN 5 FEET...EVEN AT BUOY
41043. WINDS WILL INCREASE NEXT WEEK.
&&
.PREV DISCUSSION... /ISSUED 256 PM AST FRI MAY 17 2013/
SYNOPSIS...A MID TO UPPER LEVEL TROUGH ACROSS THE CENTRAL ATLANTIC
INTO THE EASTERN CARIBBEAN WILL CONTINUE TO MOVE EAST AND AWAY FROM
THE LOCAL ISLANDS. LOCAL PRESSURE GRADIENT WILL TIGHTEN AS SURFACE
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA. A
BETTER CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED NEXT
WORK WEEK.
DISCUSSION...A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO
PREVAIL TONIGHT INTO THE WEEKEND AS TROUGH ALOFT CONTINUES TO MOVE
AWAY FROM THE LOCAL AREA. AS AFOREMENTIONED TROUGH MOVES TO THE
EAST...A WEAK MID LEVEL RIDGE WILL CONTINUE TO BUILD FROM THE
WEST. AT LOW LEVELS...LOCAL PRESSURE GRADIENT WILL TIGHTEN AS
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA.
AS RESULT...FOR THE NEXT TWO DAYS OR SO...UNDER THE PREVAILING
WIND FLOW...EXPECT PASSING SHOWERS EMBEDDED IN THE TRADES ACROSS
THE EAST COASTAL SECTIONS OF THE ISLANDS ESPECIALLY DURING THE
MORNING HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE
MAINLY FOCUSED ACROSS WESTERN PUERTO RICO DUE TO DIURNAL HEATING
AND LOCAL EFFECTS.
FOR THE UPCOMING WORK WEEK...A HIGHER AMPLITUDE TROUGH IS FORECAST
TO EXTEND FROM THE BAHAMAS INTO THE WESTERN CARIBBEAN...WITH
DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA. THIS WILL BRING
DEEP MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS OVER PUERTO RICO
AND U.S. VIRGIN ISLANDS...RESULTING IN CLOUDY AND WET CONDITIONS
WITH A GOOD CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY ESPECIALLY
THE MIDDLE/LATTER PART OF NEXT WEEK.
AVIATION...VFR CONDITIONS EXPECTED ACROSS THE LOCAL TERMINALS
THROUGH THE FORECAST PERIOD WITH THE EXCEPTION OF TJMZ AND THE
VICINITY OF TJBQ WHERE SHRA/TSRA MAY CAUSE MVFR/IFR CONDITIONS UNTIL
AROUND 18/22Z. EASTERLY WINDS WITH SEA BREEZE VARIATIONS AT AROUND
10 TO 15 KTS GUSTING TO 25KTS UNTIL 18/00Z...BECOMING LIGHTER
THEREAFTER.
MARINE...LOCAL PRESSURE GRADIENT WILL TIGHTEN DURING THE WEEKEND
AS SURFACE HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST
AREA. SEAS UP TO 5 FEET AND WINDS UP TO 21 KNOTS EXPECTED FOR
THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 87 / 10 20 20 20
STT 76 88 76 88 / 10 10 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
13/12
000
FXCA62 TJSJ 180050
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
850 PM AST FRI MAY 17 2013
.UPDATE...SHOWERS LINGERED OVER SOUTHWEST PUERTO RICO...BUT WILL BE
MOVING OFFSHORE BY ABOUT 10 PM AST. OTHERWISE PREVIOUS FORECAST
HOLDS. DRIER AIR IS JUST EAST OF PUERTO RICO AND WILL MOVE OVER
THE AREA DURING THE MORNING. ALSO STILL EXPECTING AFTERNOON
CONVECTION IN THE WEST AND SOUTHWEST...SHOULD NOT LAST AS LONG AS
TODAY HOWEVER. WILL NOT UPDATE ZONE PACKAGE.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES UNTIL
18/16Z. MVFR/IFR CONDS ARE LIKELY BTWN 18/17Z-21Z ALONG THE
CORDILLERA CENTRAL AND TJMZ IN AREAS OF +SHRA/TSRA. MOUNTAINS WILL
BE OBSCURED OVER WESTERN INTERIOR OF PR. FOR THE LEEWARD
ISLANDS...VFR CONDITIONS ARE EXPECTED. 00Z TJSJ SOUNDING INDICATES
MAINLY EAST WINDS AT 18 KNOTS OR LESS UP TO 2 KFT.
&&
.MARINE...SEAS STILL HOLDING AT NO MORE THAN 5 FEET...EVEN AT BUOY
41043. WINDS WILL INCREASE NEXT WEEK.
&&
.PREV DISCUSSION... /ISSUED 256 PM AST FRI MAY 17 2013/
SYNOPSIS...A MID TO UPPER LEVEL TROUGH ACROSS THE CENTRAL ATLANTIC
INTO THE EASTERN CARIBBEAN WILL CONTINUE TO MOVE EAST AND AWAY FROM
THE LOCAL ISLANDS. LOCAL PRESSURE GRADIENT WILL TIGHTEN AS SURFACE
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA. A
BETTER CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED NEXT
WORK WEEK.
DISCUSSION...A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO
PREVAIL TONIGHT INTO THE WEEKEND AS TROUGH ALOFT CONTINUES TO MOVE
AWAY FROM THE LOCAL AREA. AS AFOREMENTIONED TROUGH MOVES TO THE
EAST...A WEAK MID LEVEL RIDGE WILL CONTINUE TO BUILD FROM THE
WEST. AT LOW LEVELS...LOCAL PRESSURE GRADIENT WILL TIGHTEN AS
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA.
AS RESULT...FOR THE NEXT TWO DAYS OR SO...UNDER THE PREVAILING
WIND FLOW...EXPECT PASSING SHOWERS EMBEDDED IN THE TRADES ACROSS
THE EAST COASTAL SECTIONS OF THE ISLANDS ESPECIALLY DURING THE
MORNING HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE
MAINLY FOCUSED ACROSS WESTERN PUERTO RICO DUE TO DIURNAL HEATING
AND LOCAL EFFECTS.
FOR THE UPCOMING WORK WEEK...A HIGHER AMPLITUDE TROUGH IS FORECAST
TO EXTEND FROM THE BAHAMAS INTO THE WESTERN CARIBBEAN...WITH
DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA. THIS WILL BRING
DEEP MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS OVER PUERTO RICO
AND U.S. VIRGIN ISLANDS...RESULTING IN CLOUDY AND WET CONDITIONS
WITH A GOOD CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY ESPECIALLY
THE MIDDLE/LATTER PART OF NEXT WEEK.
AVIATION...VFR CONDITIONS EXPECTED ACROSS THE LOCAL TERMINALS
THROUGH THE FORECAST PERIOD WITH THE EXCEPTION OF TJMZ AND THE
VICINITY OF TJBQ WHERE SHRA/TSRA MAY CAUSE MVFR/IFR CONDITIONS UNTIL
AROUND 18/22Z. EASTERLY WINDS WITH SEA BREEZE VARIATIONS AT AROUND
10 TO 15 KTS GUSTING TO 25KTS UNTIL 18/00Z...BECOMING LIGHTER
THEREAFTER.
MARINE...LOCAL PRESSURE GRADIENT WILL TIGHTEN DURING THE WEEKEND
AS SURFACE HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST
AREA. SEAS UP TO 5 FEET AND WINDS UP TO 21 KNOTS EXPECTED FOR
THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 87 / 10 20 20 20
STT 76 88 76 88 / 10 10 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
13/12
000
FXCA62 TJSJ 180050
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
850 PM AST FRI MAY 17 2013
.UPDATE...SHOWERS LINGERED OVER SOUTHWEST PUERTO RICO...BUT WILL BE
MOVING OFFSHORE BY ABOUT 10 PM AST. OTHERWISE PREVIOUS FORECAST
HOLDS. DRIER AIR IS JUST EAST OF PUERTO RICO AND WILL MOVE OVER
THE AREA DURING THE MORNING. ALSO STILL EXPECTING AFTERNOON
CONVECTION IN THE WEST AND SOUTHWEST...SHOULD NOT LAST AS LONG AS
TODAY HOWEVER. WILL NOT UPDATE ZONE PACKAGE.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES UNTIL
18/16Z. MVFR/IFR CONDS ARE LIKELY BTWN 18/17Z-21Z ALONG THE
CORDILLERA CENTRAL AND TJMZ IN AREAS OF +SHRA/TSRA. MOUNTAINS WILL
BE OBSCURED OVER WESTERN INTERIOR OF PR. FOR THE LEEWARD
ISLANDS...VFR CONDITIONS ARE EXPECTED. 00Z TJSJ SOUNDING INDICATES
MAINLY EAST WINDS AT 18 KNOTS OR LESS UP TO 2 KFT.
&&
.MARINE...SEAS STILL HOLDING AT NO MORE THAN 5 FEET...EVEN AT BUOY
41043. WINDS WILL INCREASE NEXT WEEK.
&&
.PREV DISCUSSION... /ISSUED 256 PM AST FRI MAY 17 2013/
SYNOPSIS...A MID TO UPPER LEVEL TROUGH ACROSS THE CENTRAL ATLANTIC
INTO THE EASTERN CARIBBEAN WILL CONTINUE TO MOVE EAST AND AWAY FROM
THE LOCAL ISLANDS. LOCAL PRESSURE GRADIENT WILL TIGHTEN AS SURFACE
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA. A
BETTER CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED NEXT
WORK WEEK.
DISCUSSION...A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO
PREVAIL TONIGHT INTO THE WEEKEND AS TROUGH ALOFT CONTINUES TO MOVE
AWAY FROM THE LOCAL AREA. AS AFOREMENTIONED TROUGH MOVES TO THE
EAST...A WEAK MID LEVEL RIDGE WILL CONTINUE TO BUILD FROM THE
WEST. AT LOW LEVELS...LOCAL PRESSURE GRADIENT WILL TIGHTEN AS
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA.
AS RESULT...FOR THE NEXT TWO DAYS OR SO...UNDER THE PREVAILING
WIND FLOW...EXPECT PASSING SHOWERS EMBEDDED IN THE TRADES ACROSS
THE EAST COASTAL SECTIONS OF THE ISLANDS ESPECIALLY DURING THE
MORNING HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE
MAINLY FOCUSED ACROSS WESTERN PUERTO RICO DUE TO DIURNAL HEATING
AND LOCAL EFFECTS.
FOR THE UPCOMING WORK WEEK...A HIGHER AMPLITUDE TROUGH IS FORECAST
TO EXTEND FROM THE BAHAMAS INTO THE WESTERN CARIBBEAN...WITH
DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA. THIS WILL BRING
DEEP MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS OVER PUERTO RICO
AND U.S. VIRGIN ISLANDS...RESULTING IN CLOUDY AND WET CONDITIONS
WITH A GOOD CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY ESPECIALLY
THE MIDDLE/LATTER PART OF NEXT WEEK.
AVIATION...VFR CONDITIONS EXPECTED ACROSS THE LOCAL TERMINALS
THROUGH THE FORECAST PERIOD WITH THE EXCEPTION OF TJMZ AND THE
VICINITY OF TJBQ WHERE SHRA/TSRA MAY CAUSE MVFR/IFR CONDITIONS UNTIL
AROUND 18/22Z. EASTERLY WINDS WITH SEA BREEZE VARIATIONS AT AROUND
10 TO 15 KTS GUSTING TO 25KTS UNTIL 18/00Z...BECOMING LIGHTER
THEREAFTER.
MARINE...LOCAL PRESSURE GRADIENT WILL TIGHTEN DURING THE WEEKEND
AS SURFACE HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST
AREA. SEAS UP TO 5 FEET AND WINDS UP TO 21 KNOTS EXPECTED FOR
THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 87 / 10 20 20 20
STT 76 88 76 88 / 10 10 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
13/12
000
FXCA62 TJSJ 171856
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
256 PM AST FRI MAY 17 2013
.SYNOPSIS...A MID TO UPPER LEVEL TROUGH ACROSS THE CENTRAL ATLANTIC
INTO THE EASTERN CARIBBEAN WILL CONTINUE TO MOVE EAST AND AWAY FROM
THE LOCAL ISLANDS. LOCAL PRESSURE GRADIENT WILL TIGHTEN AS SURFACE
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA. A
BETTER CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED NEXT
WORK WEEK.
&&
.DISCUSSION...A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO
PREVAIL TONIGHT INTO THE WEEKEND AS TROUGH ALOFT CONTINUES TO MOVE
AWAY FROM THE LOCAL AREA. AS AFOREMENTIONED TROUGH MOVES TO THE
EAST...A WEAK MID LEVEL RIDGE WILL CONTINUE TO BUILD FROM THE
WEST. AT LOW LEVELS...LOCAL PRESSURE GRADIENT WILL TIGHTEN AS
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA.
AS RESULT...FOR THE NEXT TWO DAYS OR SO...UNDER THE PREVAILING
WIND FLOW...EXPECT PASSING SHOWERS EMBEDDED IN THE TRADES ACROSS
THE EAST COASTAL SECTIONS OF THE ISLANDS ESPECIALLY DURING THE
MORNING HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE
MAINLY FOCUSED ACROSS WESTERN PUERTO RICO DUE TO DIURNAL HEATING
AND LOCAL EFFECTS.
FOR THE UPCOMING WORK WEEK...A HIGHER AMPLITUDE TROUGH IS FORECAST
TO EXTEND FROM THE BAHAMAS INTO THE WESTERN CARIBBEAN...WITH
DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA. THIS WILL BRING
DEEP MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS OVER PUERTO RICO
AND U.S. VIRGIN ISLANDS...RESULTING IN CLOUDY AND WET CONDITIONS
WITH A GOOD CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY ESPECIALLY
THE MIDDLE/LATTER PART OF NEXT WEEK.
&&
.AVIATION...VFR CONDITIONS EXPECTED ACROSS THE LOCAL TERMINALS
THROUGH THE FORECAST PERIOD WITH THE EXCEPTION OF TJMZ AND THE
VICINITY OF TJBQ WHERE SHRA/TSRA MAY CAUSE MVFR/IFR CONDITIONS UNTIL
AROUND 18/22Z. EASTERLY WINDS WITH SEA BREEZE VARIATIONS AT AROUND
10 TO 15 KTS GUSTING TO 25KTS UNTIL 18/00Z...BECOMING LIGHTER
THEREAFTER.
&&
.MARINE...LOCAL PRESSURE GRADIENT WILL TIGHTEN DURING THE WEEKEND
AS SURFACE HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST
AREA. SEAS UP TO 5 FEET AND WINDS UP TO 21 KNOTS EXPECTED FOR
THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 87 / 10 20 20 20
STT 76 88 76 88 / 10 10 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
25/23
000
FXCA62 TJSJ 171856
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
256 PM AST FRI MAY 17 2013
.SYNOPSIS...A MID TO UPPER LEVEL TROUGH ACROSS THE CENTRAL ATLANTIC
INTO THE EASTERN CARIBBEAN WILL CONTINUE TO MOVE EAST AND AWAY FROM
THE LOCAL ISLANDS. LOCAL PRESSURE GRADIENT WILL TIGHTEN AS SURFACE
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA. A
BETTER CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED NEXT
WORK WEEK.
&&
.DISCUSSION...A GENERALLY FAIR WEATHER PATTERN WILL CONTINUE TO
PREVAIL TONIGHT INTO THE WEEKEND AS TROUGH ALOFT CONTINUES TO MOVE
AWAY FROM THE LOCAL AREA. AS AFOREMENTIONED TROUGH MOVES TO THE
EAST...A WEAK MID LEVEL RIDGE WILL CONTINUE TO BUILD FROM THE
WEST. AT LOW LEVELS...LOCAL PRESSURE GRADIENT WILL TIGHTEN AS
HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST AREA.
AS RESULT...FOR THE NEXT TWO DAYS OR SO...UNDER THE PREVAILING
WIND FLOW...EXPECT PASSING SHOWERS EMBEDDED IN THE TRADES ACROSS
THE EAST COASTAL SECTIONS OF THE ISLANDS ESPECIALLY DURING THE
MORNING HOURS...FOLLOWED BY AFTERNOON CONVECTION WHICH WILL BE
MAINLY FOCUSED ACROSS WESTERN PUERTO RICO DUE TO DIURNAL HEATING
AND LOCAL EFFECTS.
FOR THE UPCOMING WORK WEEK...A HIGHER AMPLITUDE TROUGH IS FORECAST
TO EXTEND FROM THE BAHAMAS INTO THE WESTERN CARIBBEAN...WITH
DIVERGENT SIDE OF ASSOCIATED JET OVER THE AREA. THIS WILL BRING
DEEP MOISTURE AND FAVORABLE UPPER LEVEL DYNAMICS OVER PUERTO RICO
AND U.S. VIRGIN ISLANDS...RESULTING IN CLOUDY AND WET CONDITIONS
WITH A GOOD CHANCE OF SHOWER AND THUNDERSTORM ACTIVITY ESPECIALLY
THE MIDDLE/LATTER PART OF NEXT WEEK.
&&
.AVIATION...VFR CONDITIONS EXPECTED ACROSS THE LOCAL TERMINALS
THROUGH THE FORECAST PERIOD WITH THE EXCEPTION OF TJMZ AND THE
VICINITY OF TJBQ WHERE SHRA/TSRA MAY CAUSE MVFR/IFR CONDITIONS UNTIL
AROUND 18/22Z. EASTERLY WINDS WITH SEA BREEZE VARIATIONS AT AROUND
10 TO 15 KTS GUSTING TO 25KTS UNTIL 18/00Z...BECOMING LIGHTER
THEREAFTER.
&&
.MARINE...LOCAL PRESSURE GRADIENT WILL TIGHTEN DURING THE WEEKEND
AS SURFACE HIGH BUILDS AND RELOCATES TO THE NORTH OF THE FORECAST
AREA. SEAS UP TO 5 FEET AND WINDS UP TO 21 KNOTS EXPECTED FOR
THE NEXT FEW DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 87 / 10 20 20 20
STT 76 88 76 88 / 10 10 30 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
25/23
000
FXCA62 TJSJ 171546
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1146 AM AST FRI MAY 17 2013
.UPDATE...CLOUDINESS HAS INCREASED THIS MORNING ACROSS PUERTO
RICO. IN ADDITION...A FEW SHOWERS HAVE BRIEFLY AFFECTED PORTIONS
OF EASTERN AND NORTHERN PUERTO RICO AS WELL AS THE WATERS TO THE
SOUTH OF SAINT CROIX.
EVEN THOUGH AVAILABLE MOISTURE IS EXPECTED TO GRADUALLY DECREASE
THROUGH THE DAY...THE AVAILABLE MOISTURE WILL COMBINE WITH THE
LOCAL EFFECTS AND DIURNAL HEATING TO CAUSE SHOWERS AND POSSIBLY
EVEN THUNDERSTORMS ACROSS WESTERN PR.
NO CHANGES WERE MADE TO THE FORECAST PACKAGE AS EVERYTHING IS IN
ALIGNMENT WITH THE LATEST GUIDANCE AND OBSERVATIONS.
&&
.AVIATION...NO SIGNIFICANT CHANGES FROM THE PREVIOUS DISCUSSION.
VFR CONDITIONS EXPECTED WITH THE EXCEPTION OF THOSE AREAS IN THE
INTERIOR AND WESTERN SECTIONS OF PR WHERE SHRA/TSRA DEVELOPMENT IS
EXPECTED AFTER 17/16Z...CAUSING MOUNTAIN OBSCURATIONS AND POSSIBLE
MVFR/IFR CONDITIONS IN AND AROUND TJMZ AND TJBQ UNTIL 16/00Z.
&&
.MARINE...SEAS UP TO 5 FEET AND WINDS UP TO 17 KNOTS EXPECTED FOR
THE NEXT FEW DAYS.
&&
.PREV DISCUSSION... /ISSUED 558 AM AST FRI MAY 17 2013/
SYNOPSIS...BASE OF MID TO UPPER LEVEL TROUGH NOW ACROSS THE
NORTHERN LEEWARDS...AND EXTENDS INTO THE SOUTHEASTERN CARIBBEAN...
WITH WEAK UPPER RIDGE EXTENDING ACROSS THE MONA PASSAGE WITH ANOTHER
THIS WILL NOW PLACE THE REGION ON THE CONVERGENT SIDE OF THE UPPER
TROUGH AND SHOULD THEREFORE LIMITED WIDESPREAD CONVECTIVE DEVELOPMENT
TODAY. AT LOW LEVELS...SURFACE HIGH PRESSURE CENTERED ACROSS THE NORTH
CENTRAL ATLANTIC WILL SPREAD AND REESTABLISH ITSELF NORTH OF THE
REGION BY SATURDAY THEN GRADUALLY TIGHTEN THE LOCAL PRESSURE GRADIENT
ACROSS THE NORTH EAST CARIBBEAN. THIS WILL ALLOW FOR AN INCREASE IN
THE EASTERLY TRADE WINDS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
DISCUSSION...UPPER TROUGH WILL CONTINUE SHIFT EASTWARDS ACROSS THE
NORTHEAST CARIBBEAN WHILE WEAKENING. LOOKING FOR INCREASING SUBSIDENCE
CAP LATER THIS EVENING AND THROUGH SATURDAY. HOWEVER...THE PERSISTENT
AND GRADUALLY INCREASING EASTERLY TRADES WILL BRING SHALLOW PATCHES
OF LOW TO MID LEVEL MOISTURE ACROSS THE AREA FROM TIME TO TIME.
THEREFORE...EXPECT SUFFICIENT LOW LEVEL MOISTURE CONVERGENCE AND
DIURNAL EFFECTS TO ALLOW FOR AFTERNOON CONVECTIVE DEVELOPMENT IN
SOME AREAS ESPECIALLY ACROSS PARTS OF THE INTERIOR AND WEST SECTIONS
OF PUERTO RICO.
INTO THE WEEKEND...LOOKING FOR A GRADUAL DRYING TREND ACROSS THE
REGION AT LEAST UNTIL SATURDAY. THIS WILL BE FOLLOWED BY INCREASING
MOISTURE AND PWAT VALUES SUNDAY INTO THE EARLY PART OF NEXT WEEK...AS
ANOTHER SHORT WAVE TROUGH WILL APPROACH THE REGION FROM THE WEST
WHILE AN EASTERLY PERTURBATION IS FORECAST TO BRING AN INCREASE IN
TRADE WIND MOISTURE TO THE ISLANDS AND SURROUNDING WATERS. FOR NOW
BASED ON LATEST MODEL GUIDANCE...EXPECT BETTER CHANCE FOR ENHANCEMENT
OF EARLY MORNING AND AFTERNOON CONVECTION DURING THAT PERIOD. UNTIL
THEN...STILL EXPECT AFTERNOON SHOWERS TO DEVELOP WITH MAINLY ISOLATED
THUNDERSTORMS EACH DAY...ESPECIALLY IN ISOLATED AREAS OVER THE INTERIOR
SECTIONS OF PUERTO RICO...THEN DECREASING BY EARLY EVENING HOURS.
AVIATION...MOSTLY VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES UNTIL
AROUND 17/16Z. MVFR OR EVEN IFR CONDITIONS ARE LIKELY BETWEEN
17/18Z-21Z ALONG THE CORDILLERA CENTRAL AND AROUND TJMZ IN AREAS OF
+SHRA/TSRA. MOUNTAINS WILL BE OBSCURED OVER WESTERN INTERIOR OF PR.
ELSEWHERE...VFR CONDITIONS ARE EXPECTED. TJSJ 17/00Z SOUNDING
INDICATED AN EASTERLY WIND FLOW UP TO 10 KNOTS ALL THE WAY FROM THE
SURFACE TO 20K FEET...BECOMING WESTERLY AND STRONGER ALOFT.
MARINE...SMALL CRAFT SHOULD EXERCISE CAUTION MAINLY ACROSS THE LOCAL
OFFSHORE WATERS...AS SEAS ARE EXPECTED TO REACH 6 FEET THROUGH THE
WEEKEND WITH INCREASING TRADE WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 87 77 / 10 0 20 20
STT 86 76 88 78 / 10 10 20 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
25/23
000
FXCA62 TJSJ 171546
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1146 AM AST FRI MAY 17 2013
.UPDATE...CLOUDINESS HAS INCREASED THIS MORNING ACROSS PUERTO
RICO. IN ADDITION...A FEW SHOWERS HAVE BRIEFLY AFFECTED PORTIONS
OF EASTERN AND NORTHERN PUERTO RICO AS WELL AS THE WATERS TO THE
SOUTH OF SAINT CROIX.
EVEN THOUGH AVAILABLE MOISTURE IS EXPECTED TO GRADUALLY DECREASE
THROUGH THE DAY...THE AVAILABLE MOISTURE WILL COMBINE WITH THE
LOCAL EFFECTS AND DIURNAL HEATING TO CAUSE SHOWERS AND POSSIBLY
EVEN THUNDERSTORMS ACROSS WESTERN PR.
NO CHANGES WERE MADE TO THE FORECAST PACKAGE AS EVERYTHING IS IN
ALIGNMENT WITH THE LATEST GUIDANCE AND OBSERVATIONS.
&&
.AVIATION...NO SIGNIFICANT CHANGES FROM THE PREVIOUS DISCUSSION.
VFR CONDITIONS EXPECTED WITH THE EXCEPTION OF THOSE AREAS IN THE
INTERIOR AND WESTERN SECTIONS OF PR WHERE SHRA/TSRA DEVELOPMENT IS
EXPECTED AFTER 17/16Z...CAUSING MOUNTAIN OBSCURATIONS AND POSSIBLE
MVFR/IFR CONDITIONS IN AND AROUND TJMZ AND TJBQ UNTIL 16/00Z.
&&
.MARINE...SEAS UP TO 5 FEET AND WINDS UP TO 17 KNOTS EXPECTED FOR
THE NEXT FEW DAYS.
&&
.PREV DISCUSSION... /ISSUED 558 AM AST FRI MAY 17 2013/
SYNOPSIS...BASE OF MID TO UPPER LEVEL TROUGH NOW ACROSS THE
NORTHERN LEEWARDS...AND EXTENDS INTO THE SOUTHEASTERN CARIBBEAN...
WITH WEAK UPPER RIDGE EXTENDING ACROSS THE MONA PASSAGE WITH ANOTHER
THIS WILL NOW PLACE THE REGION ON THE CONVERGENT SIDE OF THE UPPER
TROUGH AND SHOULD THEREFORE LIMITED WIDESPREAD CONVECTIVE DEVELOPMENT
TODAY. AT LOW LEVELS...SURFACE HIGH PRESSURE CENTERED ACROSS THE NORTH
CENTRAL ATLANTIC WILL SPREAD AND REESTABLISH ITSELF NORTH OF THE
REGION BY SATURDAY THEN GRADUALLY TIGHTEN THE LOCAL PRESSURE GRADIENT
ACROSS THE NORTH EAST CARIBBEAN. THIS WILL ALLOW FOR AN INCREASE IN
THE EASTERLY TRADE WINDS OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
DISCUSSION...UPPER TROUGH WILL CONTINUE SHIFT EASTWARDS ACROSS THE
NORTHEAST CARIBBEAN WHILE WEAKENING. LOOKING FOR INCREASING SUBSIDENCE
CAP LATER THIS EVENING AND THROUGH SATURDAY. HOWEVER...THE PERSISTENT
AND GRADUALLY INCREASING EASTERLY TRADES WILL BRING SHALLOW PATCHES
OF LOW TO MID LEVEL MOISTURE ACROSS THE AREA FROM TIME TO TIME.
THEREFORE...EXPECT SUFFICIENT LOW LEVEL MOISTURE CONVERGENCE AND
DIURNAL EFFECTS TO ALLOW FOR AFTERNOON CONVECTIVE DEVELOPMENT IN
SOME AREAS ESPECIALLY ACROSS PARTS OF THE INTERIOR AND WEST SECTIONS
OF PUERTO RICO.
INTO THE WEEKEND...LOOKING FOR A GRADUAL DRYING TREND ACROSS THE
REGION AT LEAST UNTIL SATURDAY. THIS WILL BE FOLLOWED BY INCREASING
MOISTURE AND PWAT VALUES SUNDAY INTO THE EARLY PART OF NEXT WEEK...AS
ANOTHER SHORT WAVE TROUGH WILL APPROACH THE REGION FROM THE WEST
WHILE AN EASTERLY PERTURBATION IS FORECAST TO BRING AN INCREASE IN
TRADE WIND MOISTURE TO THE ISLANDS AND SURROUNDING WATERS. FOR NOW
BASED ON LATEST MODEL GUIDANCE...EXPECT BETTER CHANCE FOR ENHANCEMENT
OF EARLY MORNING AND AFTERNOON CONVECTION DURING THAT PERIOD. UNTIL
THEN...STILL EXPECT AFTERNOON SHOWERS TO DEVELOP WITH MAINLY ISOLATED
THUNDERSTORMS EACH DAY...ESPECIALLY IN ISOLATED AREAS OVER THE INTERIOR
SECTIONS OF PUERTO RICO...THEN DECREASING BY EARLY EVENING HOURS.
AVIATION...MOSTLY VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES UNTIL
AROUND 17/16Z. MVFR OR EVEN IFR CONDITIONS ARE LIKELY BETWEEN
17/18Z-21Z ALONG THE CORDILLERA CENTRAL AND AROUND TJMZ IN AREAS OF
+SHRA/TSRA. MOUNTAINS WILL BE OBSCURED OVER WESTERN INTERIOR OF PR.
ELSEWHERE...VFR CONDITIONS ARE EXPECTED. TJSJ 17/00Z SOUNDING
INDICATED AN EASTERLY WIND FLOW UP TO 10 KNOTS ALL THE WAY FROM THE
SURFACE TO 20K FEET...BECOMING WESTERLY AND STRONGER ALOFT.
MARINE...SMALL CRAFT SHOULD EXERCISE CAUTION MAINLY ACROSS THE LOCAL
OFFSHORE WATERS...AS SEAS ARE EXPECTED TO REACH 6 FEET THROUGH THE
WEEKEND WITH INCREASING TRADE WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 87 77 / 10 0 20 20
STT 86 76 88 78 / 10 10 20 30
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&
$$
25/23
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