[top]
000
FXCA62 TJSJ 200332
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1132 PM AST FRI SEP 19 2008
.DISCUSSION...AN INCREASE IN LOW LEVEL MOISTURE IN AN INCREASING
EAST NORTHEASTERLY WIND FLOW IS EVIDENT ACROSS THE FORECAST AREA
THIS EVENING. MODELS CONTINUE TO INDICATE A FURTHER INCREASE IN
MOISTURE AND INSTABILITY ACROSS THE REGION TOMORROW...AHEAD OF AN
AREA OF DISTURBED WEATHER OVER THE LESSER ANTILLES. THE DEEPEST
MOISTURE AND BEST DYNAMICS...HOWEVER...NOW APPEAR TO BE LATE TOMORROW
NIGHT THROUGH SUNDAY...BUT THAT BEING SAID...STILL EXPECT AN
ACTIVE WEATHER DAY ACROSS PUERTO RICO SATURDAY. WENT AHEAD AND MADE SOME
MINOR TWEAKS TO THE FORECAST FOR TOMORROW AFTERNOON...MAINLY TO
SHIFT THE HIGHEST POPS TO SECTIONS OF THE INTERIOR AND SOUTHWESTERN
PUERTO RICO...AS THE PREVAILING FLOW IS EXPECTED TO REMAIN EAST
NORTHEASTERLY THROUGH THE AFTERNOON HOURS...BUT NO OTHER CHANGES
NECESSARY TO INHERITED FORECAST AT THIS TIME.
&&
.AVIATION...A TROPICAL WAVE WITH A BROAD AREA OF LOW PRESSURE IS
CROSSING THE ARC OF THE ANTILLES INTO THE EASTERN CARIBBEAN SEAS
WITH SCATTERED CLUSTERS OF CONVECTION. THIS HAS SO FAR MAINLY MISSED
THE TAF SITES IN THE NORTHEASTERN LEEWARD ISLANDS. THUNDERSTORMS IN
THE VICINITY HAVE PRODUCED GUSTS OVER 20 KNOTS. VFR CONDITIONS ARE
EXPECTED TO CONTINUE THROUGH THE NIGHT...BUT A BAND OF MOISTURE WILL
MOVE INTO THE AREA SPREADING OCCASIONAL MVFR CONDITIONS AND POSSIBLY
BRIEF IFR CONDITIONS DURING THE DAY AFTER 14Z...FIRST THROUGH TNCM
AND TKPK AND THEN INTO TISX AND TIST. CONDITIONS ARE EXPECTED TO
REMAIN VFR THROUGH 14Z ACROSS PUERTO RICO...ALTHOUGH SOME MOUNTAIN
OBSCURATIONS WILL CONTINUE THROUGH THE NIGHT. ACTIVITY WILL
INCREASE DURING THE DAY SATURDAY AND AREAS OF MVFR CONDITIONS WILL
DEVELOP AFTER 16Z...ESPECIALLY ACROSS TJMZ AND FOR BRIEF PERIODS AT
TJSJ...TJPS. ONSHORE WINDS MAY KEEP TJBQ IN VFR THROUGH THE NEXT
24 HOURS. WINDS IN THE 20/00Z SOUNDING WERE EAST NORTHEAST BELOW
25 THOUSAND FEET AND WESTERLY ABOVE. WINDS BETWEEN 2 TO 12
THOUSAND FEET WERE AROUND 20 KNOTS. WINDS ARE EXPECTED TO INCREASE
SATURDAY AFTERNOON AND BECOME MORE GUSTY IN NATURE.
&&
.PREV DISCUSSION... /ISSUED 400 PM AST FRI SEP 19 2008/
DISCUSSION...AN AREA OF DISTURBED WEATHER ASSOCIATED WITH A
TROPICAL WAVE...LOCATED OVER THE SOUTHEAST CARIBBEAN AND
EXTENDING EAST ACROSS THE LESSER ANTILLES LATE THIS AFTERNOON...
WILL CONTINUE MOVING SLOWLY WEST NORTHWEST TONIGHT THROUGH THE
UPCOMING WEEKEND...PASSING ACROSS OR JUST SOUTH OF THE LOCAL AREA
LATE SATURDAY THROUGH SUNDAY. ALTHOUGH THE TIMING HAS BEEN PUSHED
BACK SLIGHTLY...WE STILL EXPECT THAT THIS FEATURE AND ITS
ASSOCIATED MOISTURE WILL COMBINE WITH FAVORABLE UPPER LEVEL
CONDITIONS...TONIGHT THROUGH AT LEAST SATURDAY NIGHT OR SUNDAY...TO
PRODUCE INCREASING SHOWERS AND THUNDERSTORMS WITH LOCALLY GUSTY
WINDS ACROSS THE LOCAL ISLANDS. BASED ON LATEST MODEL PROJECTIONS...
IT STILL APPEARS THAT DEEP TROPICAL MOISTURE WILL BE ADVECTED
INTO/ACROSS THE LOCAL ISLANDS LATE TONIGHT/EARLY SATURDAY THROUGH
AT LEAST SATURDAY NIGHT OR SUNDAY...AS SYSTEM MOVES SLOWLY WEST
NORTHWEST. INITIALLY HOSTILE UPPER LEVEL WINDS (FOR DEVELOPMENT)
MAY GRADUALLY BECOME MORE FAVORABLE OVER THE NEXT DAY OR SO AND WE
WILL STILL NEED TO WATCH THIS SYSTEM CLOSELY. IRRESPECTIVE OF ANY
DEVELOPMENT...THE COMBINATION OF AFOREMENTIONED SLOW MOVING
DISTURBANCE...DEEP TROPICAL MOISTURE...INCREASINGLY FAVORABLE
UPPER LEVEL CONDITIONS AND LOCAL EFFECTS SHOULD RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER...WITH SIGNIFICANT AMOUNTS OF
CLOUDINESS...SHOWERS AND THUNDERSTORMS ACROSS THE FA.
IN ADDITION...THIS SYSTEM STILL HAS THE POTENTIAL TO PRODUCE AT
LEAST AREAS OF HEAVY RAINFALL ACROSS THE LOCAL ISLANDS WHICH COULD
IN TURN RESULT IN FLASH AND/OR RIVER FLOODING. THUS...ALL LOCAL
RESIDENTS AND VISITORS SHOULD CONTINUE TO CLOSELY MONITOR THIS
SYSTEM DURING THE NEXT COUPLE OF DAYS. IN ADDITION...PEOPLE ARE
REMINDED THAT IT DOES NOT HAVE TO BE RAINING IN YOUR EXACT
LOCATION FOR DANGEROUS WATER SURGES TO OCCUR IN LOCAL RIVERS AND
STREAMS. PLEASE USE EXTRA CAUTION IF VENTURING INTO ANY LOCAL
RIVERS OR STREAMS DURING THE NEXT FEW DAYS.
AVIATION...EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL
ISLANDS AND AT ALL LOCAL TAF SITES TONIGHT. HOWEVER...MVFR
CONDITIONS...BRIEF GUSTY WINDS AND LOCAL MOUNTAIN OBSCURATIONS
ARE EXPECTED IN SCATTERED TO NUMEROUS PASSING SHRA/ISOLATED TSRA.
MARINE...GENERALLY EXPECT WINDS OF 19 KNOTS OR LESS AND SEAS OF
6 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH SUNDAY.
HOWEVER...AS WE HAVE BEEN MENTIONING...THESE WINDS AND SEAS MAY
NEED TO BE INCREASED SLIGHTLY IF THE DISTURBANCE OVER THE
SOUTHEAST CARIBBEAN BECOMES STRONGER THAN CURRENTLY EXPECTED.
THERE IS A PRECAUTIONARY STATEMENT FOR THE LOCAL EASTERN CARIBBEAN
WATERS TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 88 / 50 50 50 50
STT 78 86 78 86 / 70 70 50 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
12/04/
000
FXCA62 TJSJ 192000
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
400 PM AST FRI SEP 19 2008
.DISCUSSION...AN AREA OF DISTURBED WEATHER ASSOCIATED WITH A
TROPICAL WAVE...LOCATED OVER THE SOUTHEAST CARIBBEAN AND
EXTENDING EAST ACROSS THE LESSER ANTILLES LATE THIS AFTERNOON...
WILL CONTINUE MOVING SLOWLY WEST NORTHWEST TONIGHT THROUGH THE
UPCOMING WEEKEND...PASSING ACROSS OR JUST SOUTH OF THE LOCAL AREA
LATE SATURDAY THROUGH SUNDAY. ALTHOUGH THE TIMING HAS BEEN PUSHED
BACK SLIGHTLY...WE STILL EXPECT THAT THIS FEATURE AND ITS
ASSOCIATED MOISTURE WILL COMBINE WITH FAVORABLE UPPER LEVEL
CONDITIONS...TONIGHT THROUGH AT LEAST SATURDAY NIGHT OR SUNDAY...TO
PRODUCE INCREASING SHOWERS AND THUNDERSTORMS WITH LOCALLY GUSTY
WINDS ACROSS THE LOCAL ISLANDS. BASED ON LATEST MODEL PROJECTIONS...
IT STILL APPEARS THAT DEEP TROPICAL MOISTURE WILL BE ADVECTED
INTO/ACROSS THE LOCAL ISLANDS LATE TONIGHT/EARLY SATURDAY THROUGH
AT LEAST SATURDAY NIGHT OR SUNDAY...AS SYSTEM MOVES SLOWLY WEST
NORTHWEST. INITIALLY HOSTILE UPPER LEVEL WINDS (FOR DEVELOPMENT)
MAY GRADUALLY BECOME MORE FAVORABLE OVER THE NEXT DAY OR SO AND WE
WILL STILL NEED TO WATCH THIS SYSTEM CLOSELY. IRRESPECTIVE OF ANY
DEVELOPMENT...THE COMBINATION OF AFOREMENTIONED SLOW MOVING
DISTURBANCE...DEEP TROPICAL MOISTURE...INCREASINGLY FAVORABLE
UPPER LEVEL CONDITIONS AND LOCAL EFFECTS SHOULD RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER...WITH SIGNIFICANT AMOUNTS OF
CLOUDINESS...SHOWERS AND THUNDERSTORMS ACROSS THE FA.
IN ADDITION...THIS SYSTEM STILL HAS THE POTENTIAL TO PRODUCE AT
LEAST AREAS OF HEAVY RAINFALL ACROSS THE LOCAL ISLANDS WHICH COULD
IN TURN RESULT IN FLASH AND/OR RIVER FLOODING. THUS...ALL LOCAL
RESIDENTS AND VISITORS SHOULD CONTINUE TO CLOSELY MONITOR THIS
SYSTEM DURING THE NEXT COUPLE OF DAYS. IN ADDITION...PEOPLE ARE
REMINDED THAT IT DOES NOT HAVE TO BE RAINING IN YOUR EXACT
LOCATION FOR DANGEROUS WATER SURGES TO OCCUR IN LOCAL RIVERS AND
STREAMS. PLEASE USE EXTRA CAUTION IF VENTURING INTO ANY LOCAL
RIVERS OR STREAMS DURING THE NEXT FEW DAYS.
&&
.AVIATION...EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL
ISLANDS AND AT ALL LOCAL TAF SITES TONIGHT. HOWEVER...MVFR
CONDITIONS...BRIEF GUSTY WINDS AND LOCAL MOUNTAIN OBSCURATIONS
ARE EXPECTED IN SCATTERED TO NUMEROUS PASSING SHRA/ISOLATED TSRA.
&&
.MARINE...GENERALLY EXPECT WINDS OF 19 KNOTS OR LESS AND SEAS OF
6 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH SUNDAY.
HOWEVER...AS WE HAVE BEEN MENTIONING...THESE WINDS AND SEAS MAY
NEED TO BE INCREASED SLIGHTLY IF THE DISTURBANCE OVER THE
SOUTHEAST CARIBBEAN BECOMES STRONGER THAN CURRENTLY EXPECTED.
THERE IS A PRECAUTIONARY STATEMENT FOR THE LOCAL EASTERN CARIBBEAN
WATERS TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 88 / 40 50 50 50
STT 78 86 78 86 / 60 60 50 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
BCS
000
FXCA62 TJSJ 191550
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1150 AM AST FRI SEP 19 2008
.UPDATE...EXPECT A MIXTURE OF SUNSHINE AND CLOUDS ACROSS THE LOCAL
ISLANDS THIS AFTERNOON. SCATTERED TO LOCALLY NUMEROUS SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED...BUT MAINLY OVER THE CENTRAL
AND WESTERN INTERIOR...AND SOUTHWEST SECTIONS OF PUERTO RICO AND ALONG
AND JUST OFF OF THE WEST AND NORTHWEST COASTS OF THE U.S. VIRGIN
ISLANDS. INHERITED SHORT TERM GRIDS AND ZFP HAD A GOOD HANDLE ON
EXPECTED CONDITIONS FOR THIS AFTERNOON. FOR THE COASTAL
WATERS...MADE A COUPLE OF MINOR ALTERATIONS TO THE PREVIOUS
CWF...OTHERWISE NO CHANGES. AVIATION-WISE...EXPECT PREVAILING VFR
CONDITIONS ACROSS THE LOCAL ISLANDS AND AT ALL LOCAL TAF SITES
AGAIN THIS AFTERNOON...EXCEPT MVFR CONDITIONS...BRIEF GUSTY WINDS
AND LOCAL MOUNTAIN OBSCURATIONS ARE POSSIBLE IN PASSING SHRA/TSRA.
&&
.PREV DISCUSSION... /ISSUED 516 AM AST FRI SEP 19 2008/
SYNOPSIS...
AN AREA OF DISTURBED WEATHER ASSOCIATED WITH A TROPICAL WAVE
NOW CROSSING THE LESSER ANTILLES AND ENTERING THE EASTERN
CARIBBEAN...WILL CONTINUE TO MOVE SLOWLY WEST NORTHWEST TODAY
THROUGH THE WEEKEND. THIS FEATURE AND ASSOCIATED MOISTURE WILL
MOVE ACROSS OR JUST SOUTH OF THE LOCAL AREA LATE SATURDAY THROUGH
SUNDAY.AN UPPER LOW AND ASSOCIATED TUTT CONTINUES TO SLOWLY LIFT
NORTH NORTHWEST OF THE LOCAL AREA WHILE FILLING.
DISCUSSION...
THE DISTURBED WEATHER/TROPICAL WAVE CONTINUES TO PRODUCE A BROAD
AREA OF SHOWERS AND THUNDERSTORMS OVER THE LESSER ANTILLES AS IT
MOVES SLOWLY WEST NORTHWEST. THIS FEATURE WILL UNDERGO LESSER UPPER
LEVEL SHEAR AS THE TUTT LOW LIFTS FURTHER NORTHWARDS...AND EXPECT
A GRADUAL DEVELOPMENT WITH INCREASING ASSOCIATED CONVECTION OVER
THE WEEKEND. ITS EXTENSIVE AREA OF DEEP MOISTURE WILL COMBINE WITH
LOCAL AND DIURNAL EFFECTS AS WELL AS FAVORABLE UPPER LEVEL CONDITIONS
THROUGH THE WEEKEND...TO PRODUCE SHOWERS AND THUNDERSTORMS WITH LOCALLY
GUSTY WINDS AND INCREASING SEAS ACROSS THE REGION. THEREFORE...A
FAIRLY MOIST AND UNSTABLE ATMOSPHERE WILL CONTINUE OVER THE NEXT
FEW DAYS...THEREBY INCREASING CHANCES OF SHOWERS AND THUNDERSTORM
ACTIVITY WITH LOCALLY HEAVY RAINFALL SATURDAY INTO SUNDAY.
LATEST GFS MODEL GUIDANCE SUGGESTS THAT THE MOISTURE FIELD ASSOCIATED
WITH THE TROPICAL WAVE WILL TRACK JUST SOUTH OF THE LOCAL AREA
WHILE MOVING TOWARDS THE WEST NORTHWEST. UNSETTLED WEATHER CONDITIONS...
WITH SIGNIFICANT AMOUNTS OF CLOUDINESS...SHOWERS AND THUNDERSTORMS
CAN BE EXPECTED TO CONTINUE TO DEVELOP ACROSS THE AREA TODAY AND
INTO THE EARLY PART OF THE UPCOMING WEEK AS TROPICAL WAVES WILL
APPROACHES THE REGION EVERY COUPLE DAYS OR SO. ALSO...HOW THIS
PRESENT FEATURE EVOLVES OVER THE NEXT DAY OR SO..WOULD DETERMINE
THE EXTENT OF THE RAINFALL ACROSS THE LOCAL ISLANDS AND SURROUNDING
WATERS. REGARDLESS...EXPECT CONSIDERABLE AMOUNTS OF TROPICAL MOISTURE
AND UNSTABLE CONDITIONS TO PREVAIL ACROSS THE REGION AS UPPER LEVEL
CONDITIONS BECOME MORE FAVORABLE FOR INCREASED ACTIVITY. THEREFORE
BASED ON LATEST GUIDANCE AND PRESENT CONDITIONS...EXPECT INCREASED
POTENTIAL FOR AREAS OF LOCALLY HEAVY RAINFALL ACROSS THE LOCAL...
ISLANDS WHICH IN TURN COULD LEAD TO URBAN AND FLASH AND OR RIVER
FLOODING. ALL LOCAL RESIDENTS AND VISITORS SHOULD MONITOR HOW THIS
SYSTEM UNFOLDS DURING THE NEXT COUPLE OF DAYS.
AVIATION...
CLOUDINESS AND SHOWERS AHEAD OF AN AREA OF DISTURBED WEATHER
ASSOCIATED WITH A TROPICAL WAVE ACROSS THE LEEWARD ISLANDS THIS
MORNING...WILL AFFECT TKPK AND TNCM UNTIL EARLY THIS AFTERNOON...
PRODUCING BRIEF MVFR OR EVEN IFR CONDITIONS UNTIL AT LEAST 18Z.
TEMPORARY MVFR CONDITIONS WILL SPREAD ACROSS TIST AND TISX
GENERALLY AFTER 17Z. LOW LEVEL MOISTURE AND GOOD HEATING WITH
NORTHEASTERLY WIND FLOW WILL BRING CONVECTION TO THE SOUTHWEST TWO
THIRDS OF PUERTO RICO AFTER 17Z...LASTING UNTIL AT LEAST 23Z...WITH
MOUNTAIN OBSCURATIONS...LOWER CEILINGS AND VISIBILITIES IN LOCALLY
HEAVY RAIN ACROSS TJPS AND TJMZ. PERIODS OF MVFR ARE ALSO EXPECTED
THIS AFTERNOON ACROSS TJSJ AND TJBQ IN SHRA UNTIL AT LEAST 22Z.
LATEST TJSJ 00Z SOUNDING INDICATED AN EAST NORTHEAST WIND FLOW UP
TO 20 KNOTS FROM THE SURFACE TO AROUND 20K FEET.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 87 77 / 40 40 50 50
STT 86 78 86 78 / 40 60 60 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
71/06
000
FXCA62 TJSJ 190916
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
516 AM AST FRI SEP 19 2008
.SYNOPSIS...
AN AREA OF DISTURBED WEATHER ASSOCIATED WITH A TROPICAL WAVE
NOW CROSSING THE LESSER ANTILLES AND ENTERING THE EASTERN
CARIBBEAN...WILL CONTINUE TO MOVE SLOWLY WEST NORTHWEST TODAY
THROUGH THE WEEKEND. THIS FEATURE AND ASSOCIATED MOISTURE WILL
MOVE ACROSS OR JUST SOUTH OF THE LOCAL AREA LATE SATURDAY THROUGH
SUNDAY.AN UPPER LOW AND ASSOCIATED TUTT CONTINUES TO SLOWLY LIFT
NORTH NORTHWEST OF THE LOCAL AREA WHILE FILLING.
&&
.DISCUSSION...
THE DISTURBED WEATHER/TROPICAL WAVE CONTINUES TO PRODUCE A BROAD
AREA OF SHOWERS AND THUNDERSTORMS OVER THE LESSER ANTILLES AS IT
MOVES SLOWLY WEST NORTHWEST. THIS FEATURE WILL UNDERGO LESSER UPPER
LEVEL SHEAR AS THE TUTT LOW LIFTS FURTHER NORTHWARDS...AND EXPECT
A GRADUAL DEVELOPMENT WITH INCREASING ASSOCIATED CONVECTION OVER
THE WEEKEND. ITS EXTENSIVE AREA OF DEEP MOISTURE WILL COMBINE WITH
LOCAL AND DIURNAL EFFECTS AS WELL AS FAVORABLE UPPER LEVEL CONDITIONS
THROUGH THE WEEKEND...TO PRODUCE SHOWERS AND THUNDERSTORMS WITH LOCALLY
GUSTY WINDS AND INCREASING SEAS ACROSS THE REGION. THEREFORE...A
FAIRLY MOIST AND UNSTABLE ATMOSPHERE WILL CONTINUE OVER THE NEXT
FEW DAYS...THEREBY INCREASING CHANCES OF SHOWERS AND THUNDERSTORM
ACTIVITY WITH LOCALLY HEAVY RAINFALL SATURDAY INTO SUNDAY.
LATEST GFS MODEL GUIDANCE SUGGESTS THAT THE MOISTURE FIELD ASSOCIATED
WITH THE TROPICAL WAVE WILL TRACK JUST SOUTH OF THE LOCAL AREA
WHILE MOVING TOWARDS THE WEST NORTHWEST. UNSETTLED WEATHER CONDITIONS...
WITH SIGNIFICANT AMOUNTS OF CLOUDINESS...SHOWERS AND THUNDERSTORMS
CAN BE EXPECTED TO CONTINUE TO DEVELOP ACROSS THE AREA TODAY AND
INTO THE EARLY PART OF THE UPCOMING WEEK AS TROPICAL WAVES WILL
APPROACHES THE REGION EVERY COUPLE DAYS OR SO. ALSO...HOW THIS
PRESENT FEATURE EVOLVES OVER THE NEXT DAY OR SO..WOULD DETERMINE
THE EXTENT OF THE RAINFALL ACROSS THE LOCAL ISLANDS AND SURROUNDING
WATERS. REGARDLESS...EXPECT CONSIDERABLE AMOUNTS OF TROPICAL MOISTURE
AND UNSTABLE CONDITIONS TO PREVAIL ACROSS THE REGION AS UPPER LEVEL
CONDITIONS BECOME MORE FAVORABLE FOR INCREASED ACTIVITY. THEREFORE
BASED ON LATEST GUIDANCE AND PRESENT CONDITIONS...EXPECT INCREASED
POTENTIAL FOR AREAS OF LOCALLY HEAVY RAINFALL ACROSS THE LOCAL...
ISLANDS WHICH IN TURN COULD LEAD TO URBAN AND FLASH AND OR RIVER
FLOODING. ALL LOCAL RESIDENTS AND VISITORS SHOULD MONITOR HOW THIS
SYSTEM UNFOLDS DURING THE NEXT COUPLE OF DAYS.
&&
.AVIATION...
CLOUDINESS AND SHOWERS AHEAD OF AN AREA OF DISTURBED WEATHER
ASSOCIATED WITH A TROPICAL WAVE ACROSS THE LEEWARD ISLANDS THIS
MORNING...WILL AFFECT TKPK AND TNCM UNTIL EARLY THIS AFTERNOON...
PRODUCING BRIEF MVFR OR EVEN IFR CONDITIONS UNTIL AT LEAST 18Z.
TEMPORARY MVFR CONDITIONS WILL SPREAD ACROSS TIST AND TISX
GENERALLY AFTER 17Z. LOW LEVEL MOISTURE AND GOOD HEATING WITH
NORTHEASTERLY WIND FLOW WILL BRING CONVECTION TO THE SOUTHWEST TWO
THIRDS OF PUERTO RICO AFTER 17Z...LASTING UNTIL AT LEAST 23Z...WITH
MOUNTAIN OBSCURATIONS...LOWER CEILINGS AND VISIBILITIES IN LOCALLY
HEAVY RAIN ACROSS TJPS AND TJMZ. PERIODS OF MVFR ARE ALSO EXPECTED
THIS AFTERNOON ACROSS TJSJ AND TJBQ IN SHRA UNTIL AT LEAST 22Z.
LATEST TJSJ 00Z SOUNDING INDICATED AN EAST NORTHEAST WIND FLOW UP
TO 20 KNOTS FROM THE SURFACE TO AROUND 20K FEET.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 87 77 / 40 40 50 50
STT 86 78 86 78 / 40 60 60 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
72/09/
000
FXCA62 TJSJ 190323
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1123 PM AST THU SEP 18 2008
.DISCUSSION...AN AREA OF DISTURBED WEATHER ACROSS THE LEEWARD
ISLANDS IS EXPECTED TO SLOWLY MOVE WEST NORTHWEST OVER THE NEXT
FEW DAYS...EVENTUALLY SPREADING DEEP MOISTURE ACROSS THE LOCAL
ISLANDS LATE TOMORROW AFTERNOON THROUGH THE UPCOMING WEEKEND. THIS
AREA OF SHOWERS AND THUNDERSTORMS STILL HAS SOME POTENTIAL FOR
DEVELOPMENT...BUT MAIN EFFECT LOCALLY WILL BE AN INCREASE IN
SHOWER ACTIVITY...WITH THE POTENTIAL FOR SOME HEAVY RAIN...THIS
UPCOMING WEEKEND. WENT AHEAD AND CONTINUED TO TREND THE POPS UP
FOR THE FRIDAY NIGHT THROUGH SUNDAY TIME PERIOD...AND ALSO BUMPED
THE WINDS A COUPLE OF KNOTS OVER THE LOCAL WATERS...BUT OTHERWISE
NO SIGNIFICANT CHANGES NECESSARY TO INHERITED FORECAST PACKAGE
THIS EVENING.
&&
AVIATION UPDATE...CONVECTIVE ACTIVITY HAS DECREASED CONSIDERABLY
ACROSS THE FORECAST AREA THIS EVENING. MODELS ARE SHOWING INCREASING
MOISTURE FROM THE SOUTH SOUTHEAST FRIDAY OVER THE TAF SITES IN THE
LEEWARD ISLANDS FROM 12-18Z. UNTIL THAT TIME VFR WEATHER IS
EXPECTED TO PREDOMINATE. AFTER 16Z PERIODS OF MVFR...AND EVEN
IFR...CONDITIONS ARE EXPECTED IN THE NORTHEAST LEEWARD ISLANDS IN
SHOWERS AND THUNDERSTORMS. MVFR CONDITIONS ARE POSSIBLE AT TIST
AND TISX GENERALLY AFTER 19/18Z...WITH CONDITIONS DETERIORATING
AROUND 20/00Z. LOW LEVEL MOISTURE AND GOOD HEATING WITH
NORTHEASTERLY FLOW WILL BRING CONVECTION TO THE SOUTHWEST TWO
THIRDS OF PUERTO RICO AFTER 16Z...WITH ATTENDANT MOUNTAIN
OBSCURATIONS LOWER CEILINGS AND VISIBILITIES IN LOCALLY HEAVY
RAIN. WINDS WERE NORTHEASTERLY UP THROUGH 25 THOUSAND FEET IN THE
19/00Z SOUNDING WITH WESTERLY WINDS ABOVE. CONDITIONS WILL
DETERIORATE WESTWARD ACROSS THE CARIBBEAN OVER THE NEXT 72
HOURS...WITH SOME INCREASE IN SURFACE WINDS AND LOW LEVEL
TURBULENCE AND GENERAL CONVECTIVE ACTIVITY.
&&
.PREV DISCUSSION... /ISSUED 438 PM AST THU SEP 18 2008/
DISCUSSION...AN AREA OF DISTURBED WEATHER LOCATED OVER THE LESSER
ANTILLES LATE THIS AFTERNOON...WILL MOVE SLOWLY WEST NORTHWEST
ACROSS THE EASTERN CARIBBEAN TONIGHT THROUGH FRIDAY...AND THEN
MORE NORTHWEST FRIDAY NIGHT THROUGH SATURDAY NIGHT PASSING ACROSS
OR JUST SOUTH OF THE LOCAL AREA. THIS FEATURE...PER NCEP/PMDCA
MOST LIKELY A TUTT INDUCED PERTURBATION...AND ITS ASSOCIATED
MOISTURE WILL COMBINE WITH INCREASINGLY FAVORABLE UPPER LEVEL
CONDITIONS TONIGHT THROUGH AT LEAST SATURDAY NIGHT...TO PRODUCE
INCREASING SHOWERS AND THUNDERSTORMS WITH LOCALLY GUSTY WINDS
ACROSS THE LOCAL ISLANDS. BASED ON LATEST MODEL PROJECTIONS...
DEEP TROPICAL MOISTURE WILL BE ADVECTED INTO/ACROSS THE LOCAL
ISLANDS LATE FRIDAY/FRIDAY NIGHT THROUGH AT LEAST SATURDAY
NIGHT...AS SYSTEM MOVES SLOWLY WEST NORTHWEST TO NORTHWEST.
INITIALLY HOSTILE UPPER LEVEL WINDS (FOR DEVELOPMENT) MAY
GRADUALLY BECOME MORE FAVORABLE OVER THE NEXT DAY OR SO AND WE
WILL NEED TO WATCH THIS SYSTEM CLOSELY. IRRESPECTIVE OF ANY
DEVELOPMENT...THE COMBINATION OF AFOREMENTIONED SLOW MOVING
DISTURBANCE...DEEP TROPICAL MOISTURE...INCREASINGLY FAVORABLE
UPPER LEVEL CONDITIONS AND LOCAL EFFECTS SHOULD RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER...WITH SIGNIFICANT AMOUNTS
OF CLOUDINESS...SHOWERS AND THUNDERSTORMS ACROSS THE FA.
IN ADDITION...THIS SYSTEM HAS THE POTENTIAL TO EVENTUALLY PRODUCE
AT LEAST AREAS OF HEAVY RAINFALL ACROSS THE LOCAL ISLANDS WHICH
COULD IN TURN RESULT IN FLASH AND/OR RIVER FLOODING. THEREFORE...
ALL LOCAL RESIDENTS AND VISITORS SHOULD MONITOR THIS SYSTEM
CLOSELY DURING THE NEXT COUPLE OF DAYS. IN ADDITION...PEOPLE ARE
REMINDED THAT IT DOES NOT HAVE TO BE RAINING IN YOUR EXACT
LOCATION FOR DANGEROUS WATER SURGES TO OCCUR IN LOCAL RIVERS AND
STREAMS.
AVIATION...EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL
ISLANDS AND AT ALL LOCAL TAF SITES TONIGHT. HOWEVER...MVFR
CONDITIONS...BRIEF GUSTY WINDS AND LOCAL MOUNTAIN OBSCURATIONS
ARE EXPECTED IN SCATTERED PASSING SHRA/ISOLATED TSRA.
MARINE...GENERALLY EXPECT WINDS OF 18 KNOTS OR LESS AND SEAS OF 6
FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH SATURDAY.
HOWEVER...THESE WINDS AND SEAS MAY NEED TO BE INCREASED IF THE
DISTURBANCE OVER THE LESSER ANTILLES BECOMES STRONGER THAN
CURRENTLY EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 78 88 77 88 / 50 20 40 50
STT 78 86 78 86 / 50 40 60 60
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
12/04/
000
FXCA62 TJSJ 182038
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
438 PM AST THU SEP 18 2008
.DISCUSSION...AN AREA OF DISTURBED WEATHER LOCATED OVER THE LESSER
ANTILLES LATE THIS AFTERNOON...WILL MOVE SLOWLY WEST NORTHWEST
ACROSS THE EASTERN CARIBBEAN TONIGHT THROUGH FRIDAY...AND THEN
MORE NORTHWEST FRIDAY NIGHT THROUGH SATURDAY NIGHT PASSING ACROSS
OR JUST SOUTH OF THE LOCAL AREA. THIS FEATURE...PER NCEP/PMDCA
MOST LIKELY A TUTT INDUCED PERTURBATION...AND ITS ASSOCIATED
MOISTURE WILL COMBINE WITH INCREASINGLY FAVORABLE UPPER LEVEL
CONDITIONS TONIGHT THROUGH AT LEAST SATURDAY NIGHT...TO PRODUCE
INCREASING SHOWERS AND THUNDERSTORMS WITH LOCALLY GUSTY WINDS
ACROSS THE LOCAL ISLANDS. BASED ON LATEST MODEL PROJECTIONS...
DEEP TROPICAL MOISTURE WILL BE ADVECTED INTO/ACROSS THE LOCAL
ISLANDS LATE FRIDAY/FRIDAY NIGHT THROUGH AT LEAST SATURDAY
NIGHT...AS SYSTEM MOVES SLOWLY WEST NORTHWEST TO NORTHWEST.
INITIALLY HOSTILE UPPER LEVEL WINDS (FOR DEVELOPMENT) MAY
GRADUALLY BECOME MORE FAVORABLE OVER THE NEXT DAY OR SO AND WE
WILL NEED TO WATCH THIS SYSTEM CLOSELY. IRRESPECTIVE OF ANY
DEVELOPMENT...THE COMBINATION OF AFOREMENTIONED SLOW MOVING
DISTURBANCE...DEEP TROPICAL MOISTURE...INCREASINGLY FAVORABLE
UPPER LEVEL CONDITIONS AND LOCAL EFFECTS SHOULD RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER...WITH SIGNIFICANT AMOUNTS
OF CLOUDINESS...SHOWERS AND THUNDERSTORMS ACROSS THE FA.
IN ADDITION...THIS SYSTEM HAS THE POTENTIAL TO EVENTUALLY PRODUCE
AT LEAST AREAS OF HEAVY RAINFALL ACROSS THE LOCAL ISLANDS WHICH
COULD IN TURN RESULT IN FLASH AND/OR RIVER FLOODING. THEREFORE...
ALL LOCAL RESIDENTS AND VISITORS SHOULD MONITOR THIS SYSTEM
CLOSELY DURING THE NEXT COUPLE OF DAYS. IN ADDITION...PEOPLE ARE
REMINDED THAT IT DOES NOT HAVE TO BE RAINING IN YOUR EXACT
LOCATION FOR DANGEROUS WATER SURGES TO OCCUR IN LOCAL RIVERS AND
STREAMS.
&&
.AVIATION...EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL
ISLANDS AND AT ALL LOCAL TAF SITES TONIGHT. HOWEVER...MVFR
CONDITIONS...BRIEF GUSTY WINDS AND LOCAL MOUNTAIN OBSCURATIONS
ARE EXPECTED IN SCATTERED PASSING SHRA/ISOLATED TSRA.
&&
.MARINE...GENERALLY EXPECT WINDS OF 18 KNOTS OR LESS AND SEAS OF 6
FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH SATURDAY.
HOWEVER...THESE WINDS AND SEAS MAY NEED TO BE INCREASED IF THE
DISTURBANCE OVER THE LESSER ANTILLES BECOMES STRONGER THAN
CURRENTLY EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 78 88 77 88 / 50 40 40 50
STT 78 86 78 86 / 60 60 50 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
BCS
000
FXCA62 TJSJ 181559
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1159 AM AST THU SEP 18 2008
.UPDATE...EXPECT A MIXTURE OF SUNSHINE AND CLOUDS ACROSS THE LOCAL
ISLANDS THIS AFTERNOON. SCATTERED TO LOCALLY NUMEROUS SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED...BUT MAINLY OVER THE CENTRAL
AND WESTERN INTERIOR AND WEST SECTIONS OF PUERTO RICO AND ALONG
AND JUST OFF OF THE WEST AND NORTHWEST COASTS OF THE U.S. VIRGIN
ISLANDS. INHERITED SHORT TERM GRIDS AND ZFP HAD A GOOD HANDLE ON
EXPECTED CONDITIONS FOR THIS AFTERNOON. FOR THE COASTAL
WATERS...MADE A COUPLE OF MINOR ALTERATIONS TO THE PREVIOUS
CWF...MAINLY TO THE SYNOPSIS... OTHERWISE NO CHANGES. AVIATION-
WISE...EXPECT PREVAILING VFR CONDITIONS ACROSS THE LOCAL ISLANDS
AND AT ALL LOCAL TAF SITES AGAIN THIS AFTERNOON...EXCEPT MVFR
CONDITIONS...BRIEF GUSTY WINDS AND LOCAL MOUNTAIN OBSCURATIONS ARE
POSSIBLE IN PASSING SHRA/TSRA.
&&
.PREV DISCUSSION... /ISSUED 454 AM AST THU SEP 18 2008/
SYNOPSIS...
AN UPPER-LEVEL TROUGH (TUTT) EXTENDS FROM A LOW LOCATED NEAR 22N
67W...SOUTHWARDS ACROSS PUERTO RICO THEN INTO THE EASTERN CARIBBEAN.
THE STRONG SOUTHWESTERLY FLOW EAST OF THIS TROUGH AXIS CONTINUED TO
TRANSPORT MOIST TROPICAL AIR ACROSS LESSER ANTILLES BRINGING CONSIDERABLE
AMOUNTS OF MID TO UPPER LEVEL CLOUDINESS ACROSS AND TO THE EAST OF THE
ISLAND CHAIN. IN THE LOW LEVELS MOISTURE ENHANCED BY THE UPPER LEVEL
TUTT AND TRAILING A TROPICAL WAVE NOW LOCATED NEAR NEAR 69 WEST WILL
CONTINUE TO MOVE ACROSS THE NORTHEAST CARIBBEAN AND AFFECT THE LOCAL
AREA TODAY THROUGH FRIDAY.
DISCUSSION...
UPPER LEVEL TROUGH ACROSS THE REGION HELPING TO MAINTAIN VERY UNSTABLE
CONDITIONS ACROSS THE REGION AND INDUCING CONSIDERABLE AMOUNTS OF
CONVECTION ALONG THE TRAILING EDGE OF THE TROPICAL WAVE AXIS...WHICH
IS NOW MOVING ACROSS THE U.S. VIRGIN ISLANDS. LATEST GFS MODEL
GUIDANCE CONTINUED TO SUGGEST THAT THIS MOIST AND UNSTABLE
ENVIRONMENT WILL REMAIN IN PLACE ACROSS THE REGION THROUGH REST
OF THE WEEK...AS THE TUTT WILL LIFT NORTH NORTHWEST TO JUST NORTH
OF THE AREA. IN THE MEANTIME....THE BROAD LOW LEVEL TROUGHINESS
ACROSS THE EASTERN CARIBBEAN BASIN WILL HELP MAINTAIN A PREVAILING
EAST SOUTHEAST LOW LEVEL WIND FLOW WITH FAIR AMOUNTS OF ITCZ
MOISTURE EXPECTED TO BE LIFTED NORTHWARDS ACROSS THE LOCAL AREA.
BY SUNDAY...A BULGE (INDUCED TROUGHINESS) IN THE ITCZ WILL LIFT
NORTHWARD ACROSS THE LOCAL FORECAST AREA AND FURTHER INCREASE THE
THE CHANCES OF MORE ACTIVE WEATHER CONDITIONS DURING THE DAYTIME.
THE AVAILABLE MOISTURE COMBINED WITH THE PROXIMITY OF THE UPPER
LEVEL TROUGH JUST NORTH OF THE AREA...AND THE LOCAL AND DIURNAL
INFLUENCES WILL MAKE FOR MOSTLY ACTIVE WEATHER CONDITIONS FOR THE
REST OF THE WEEK AND WELL INTO THE WEEKEND.
AVIATION...
CLOUDINESS AND SHOWERS BEHIND A TROPICAL WAVE WHOSE AXIS IS
ACROSS THE MONA PASSAGE THIS MORNING WILL CONTINUE ACROSS THE
REGION PRODUCING TEMPORARY MVFR CONDITIONS ACROSS TKPK...TNCM...
TISX AND TIST UNTIL AT LEAST 16Z. FOR THE AFTERNOON HOURS...THIS
MOISTURE WILL TRACK WESTWARD ACROSS THE REST OF THE REGION...AND
WILL COMBINE WITH DIURNAL HEATING AND LOCAL EFFECTS...RESULTING IN
DIURNALLY DRIVEN CONVECTION ACROSS THE INTERIOR AND WESTERN
SECTIONS OF PUERTO RICO. THIS WILL RESULT IN MOUNTAIN OBSCURATIONS
AND PERIODS OF MVFR OR EVEN IFR CONDITIONS ACROSS TJSJ...TJPS...
TJMZ AND TJBQ FROM 17-23Z. LATEST TJSJ 00Z SOUNDING INDICATED A
LIGHT EAST TO SOUTHEAST WIND FLOW FROM THE SURFACE TO AROUND 6K
FEET...BECOMING MORE SOUTHERLY FROM 6-30K FEET.
MARINE...
OUTSIDE OF THE EXPECTED SHOWERS AND ISOLATED THUNDERSTORM ACTIVITY...
MARINERS CAN EXPECT WINDS OF 16 KNOTS OR LESS AND SEAS OF 4 FEET OR
LESS ACROSS THE REGIONAL WATERS TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 88 77 / 50 50 40 40
STT 86 78 86 78 / 50 60 60 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
71/06
000
FXCA62 TJSJ 180854
AFDSJU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
454 AM AST THU SEP 18 2008
.SYNOPSIS...
AN UPPER-LEVEL TROUGH (TUTT) EXTENDS FROM A LOW LOCATED NEAR 22N
67W...SOUTHWARDS ACROSS PUERTO RICO THEN INTO THE EASTERN CARIBBEAN.
THE STRONG SOUTHWESTERLY FLOW EAST OF THIS TROUGH AXIS CONTINUED TO
TRANSPORT MOIST TROPICAL AIR ACROSS LESSER ANTILLES BRINGING CONSIDERABLE
AMOUNTS OF MID TO UPPER LEVEL CLOUDINESS ACROSS AND TO THE EAST OF THE
ISLAND CHAIN. IN THE LOW LEVELS MOISTURE ENHANCED BY THE UPPER LEVEL
TUTT AND TRAILING A TROPICAL WAVE NOW LOCATED NEAR NEAR 69 WEST WILL
CONTINUE TO MOVE ACROSS THE NORTHEAST CARIBBEAN AND AFFECT THE LOCAL
AREA TODAY THROUGH FRIDAY.
&&
.DISCUSSION...
UPPER LEVEL TROUGH ACROSS THE REGION HELPING TO MAINTAIN VERY UNSTABLE
CONDITIONS ACROSS THE REGION AND INDUCING CONSIDERABLE AMOUNTS OF
CONVECTION ALONG THE TRAILING EDGE OF THE TROPICAL WAVE AXIS...WHICH
IS NOW MOVING ACROSS THE U.S. VIRGIN ISLANDS. LATEST GFS MODEL
GUIDANCE CONTINUED TO SUGGEST THAT THIS MOIST AND UNSTABLE
ENVIRONMENT WILL REMAIN IN PLACE ACROSS THE REGION THROUGH REST
OF THE WEEK...AS THE TUTT WILL LIFT NORTH NORTHWEST TO JUST NORTH
OF THE AREA. IN THE MEANTIME....THE BROAD LOW LEVEL TROUGHINESS
ACROSS THE EASTERN CARIBBEAN BASIN WILL HELP MAINTAIN A PREVAILING
EAST SOUTHEAST LOW LEVEL WIND FLOW WITH FAIR AMOUNTS OF ITCZ
MOISTURE EXPECTED TO BE LIFTED NORTHWARDS ACROSS THE LOCAL AREA.
BY SUNDAY...A BULGE (INDUCED TROUGHINESS) IN THE ITCZ WILL LIFT
NORTHWARD ACROSS THE LOCAL FORECAST AREA AND FURTHER INCREASE THE
THE CHANCES OF MORE ACTIVE WEATHER CONDITIONS DURING THE DAYTIME.
THE AVAILABLE MOISTURE COMBINED WITH THE PROXIMITY OF THE UPPER
LEVEL TROUGH JUST NORTH OF THE AREA...AND THE LOCAL AND DIURNAL
INFLUENCES WILL MAKE FOR MOSTLY ACTIVE WEATHER CONDITIONS FOR THE
REST OF THE WEEK AND WELL INTO THE WEEKEND.
&&
.AVIATION...
CLOUDINESS AND SHOWERS BEHIND A TROPICAL WAVE WHOSE AXIS IS
ACROSS THE MONA PASSAGE THIS MORNING WILL CONTINUE ACROSS THE
REGION PRODUCING TEMPORARY MVFR CONDITIONS ACROSS TKPK...TNCM...
TISX AND TIST UNTIL AT LEAST 16Z. FOR THE AFTERNOON HOURS...THIS
MOISTURE WILL TRACK WESTWARD ACROSS THE REST OF THE REGION...AND
WILL COMBINE WITH DIURNAL HEATING AND LOCAL EFFECTS...RESULTING IN
DIURNALLY DRIVEN CONVECTION ACROSS THE INTERIOR AND WESTERN
SECTIONS OF PUERTO RICO. THIS WILL RESULT IN MOUNTAIN OBSCURATIONS
AND PERIODS OF MVFR OR EVEN IFR CONDITIONS ACROSS TJSJ...TJPS...
TJMZ AND TJBQ FROM 17-23Z. LATEST TJSJ 00Z SOUNDING INDICATED A
LIGHT EAST TO SOUTHEAST WIND FLOW FROM THE SURFACE TO AROUND 6K
FEET...BECOMING MORE SOUTHERLY FROM 6-30K FEET.
&&
.MARINE...
OUTSIDE OF THE EXPECTED SHOWERS AND ISOLATED THUNDERSTORM ACTIVITY...
MARINERS CAN EXPECT WINDS OF 16 KNOTS OR LESS AND SEAS OF 4 FEET OR
LESS ACROSS THE REGIONAL WATERS TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 88 77 / 50 50 40 40
STT 86 78 86 78 / 50 60 60 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&
$$
72/09/
| 
