Post by Deleted on Nov 5, 2014 4:21:24 GMT -6
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
530 AM AST WED NOV 5 2014
.SYNOPSIS...SATELLITE IMAGERY AND DOPPLER WEATHER RADAR SHOWED DEEP
LAYER MOISTURE AND WIDESPREAD CONVECTION SPREAD ACROSS THE NORTHEASTERN
CARIBBEAN AND EXTENDING SOUTHWEST INTO THE CENTRAL CARIBBEAN. THIS
AREA OF DISTURBED WEATHER IS DUE TO THE INTERACTION OF MOISTURE
CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY/SHEARLINE SAGGING
SOUTHWARDS ACROSS HISPANIOLA AND THE MONA PASSAGE... AND A DEEPENING
AND ELONGATED TUTT WHICH EXTENDS SOUTHWARDS FROM THE WESTERN ATLANTIC
INTO THE CENTRAL CARIBBEAN. LATEST MODEL GUIDANCE CONTINUED TO SUGGEST
A TUTT LOW IS TO FORM JUST SOUTH OF HISPANIOLA BY EARLY THURSDAY THEN
SETTLE ACROSS THE CENTRAL CARIBBEAN...BEFORE SLOWLY LIFTING NORTH
NORTHEAST ACROSS THE LOCAL REGION ON FRIDAY AND SATURDAY. IN THE
MEANTIME AN INDUCED SURFACE TROUGH IS TO SLOWLY SHIFT WEST NORTHWEST
ACROSS THE REGION THROUGH THE END OF THE WEEK AN INTO THE WEEKEND.
&&
.DISCUSSION...THE ELONGATED MID TO UPPER-LEVEL TROUGH OVER THE WESTERN
ATLANTIC WILL CONTINUE TO AMPLIFY AND DIG FURTHER SOUTH INTO THE CENTRAL
CARIBBEAN TODAY. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE AFOREMENTIONED
FRONTAL BOUNDARY AND STRONG DIFFLUENT PATTERN ALOFT WILL CONTINUE TO
ENHANCE SHOWERS AND THUNDERSTORMS DEVELOPMENT ACROSS THE REGION DURING
THE DAY AND THROUGH THE END OF THE WEEK. BROAD TUTT INDUCED SURFACE
TROUGH IS TO SHIFT WEST NORTHWEST ACROSS THE REGION THROUGH THURSDAY
IN TANDEM WITH THE DEVELOPING TUTT LOW EXPECTED TO FORM AND SETTLE
ACROSS THE CENTRAL CARIBBEAN BY THURSDAY. THE TUTT LOW IS TO THEN
LIFT NORTH NORTHEAST ACROSS THE REGION BY THE END OF THE WEEK WHILE
FILLING/WEAKENING.
ALTHOUGH THERE HAS BEEN A SLIGHT DECREASE IN CONVECTION ACROSS MOST
OF THE ISLANDS DURING THE OVERNIGHT AND EARLY MORNING HOURS... THE
POTENTIAL FOR ADDITIONAL DEVELOPMENT REMAINS HIGH LATER IN THE DAY.
ANOTHER ROUND OF DEEP CONVECTION IS FORECAST...AS THE UPPER LEVEL LOW
WILL CONTINUE TO DEVELOP AND ENHANCE THUNDERSTORM DEVELOPMENT. THIS
WILL AGAIN LEAD TO PERIODS OF LOCALLY HEAVY RAINFALL AND FREQUENT
LIGHTNING ACROSS PORTIONS OF THE ISLANDS.
LATEST MODEL GUIDANCE CONTINUED TO SUGGEST MODERATE AMOUNTS OF
TROPICAL MOISTURE ADVECTION ACROSS THE REGION INTO THE UPCOMING
WEEKEND. DUE TO THIS MOIST AND VERY UNSTABLE ENVIRONMENT...THE
POTENTIAL FOR PERIODS OF LOCALLY HEAVY RAINFALL AND POSSIBLE
FLOODING WILL CONTINUE ACROSS THE ISLANDS TODAY AND POSSIBLY
THROUGH THURSDAY. IN ADDITION SOILS REMAIN VERY SATURATED AND
UNSTABLE ACROSS THE ISLANDS DUE TO RECENT RAINS. ADDITIONAL
RAINFALL WILL ONLY AGGRAVATE THE SITUATION AND LEAD TO MUDSLIDE
AND ROCKFALL IN AREAS OF STEEP TERRAIN. FOR THIS REASON THE FLASH
FLOOD WATCH WILL REMAIN IN EFFECT AT LEAST UNTIL LATER THIS
AFTERNOON...AND COULD POSSIBLY BE EXTENDED UNTIL THURSDAY. HOWEVER
WILL CONTINUE TO CLOSELY MONITOR THE ONGOING SITUATION...AND A
DECISION WILL BE MADE LATER ON IN THE DAY.
TEMPERATURES WILL BE MUCH COOLER THAN NORMAL DURING THE NEXT
COUPLE OF DAYS DUE TO THE CLOUDY SKIES AND THE OCCASIONAL RAINS.
FAIR AMOUNTS OF MOISTURE WILL CONTINUE ACROSS THE REGION THROUGH
THE WEEKEND...WITH PRECIPITABLE WATER VALUES TO RANGE BETWEEN 1.7
TO 2.0 INCHES OR SO. LOW LEVEL WINDS WILL REMAIN FAIRLY LIGHT BUT
SOUTHERLY TODAY...GRADUALLY BECOME MORE SOUTHEASTERLY THURSDAY AND
THROUGH THE WEEKEND. A SOMEWHAT DRIER AIR MASS IS EXPECTED TO FILTER
IN BY EARLY NEXT WEEK WHEN THE REGION RETURNS TO A MORE EASTERLY
WIND FLOW AND HIGH PRESSURE BUILDS ALOFT.
&&
.AVIATION...UNSTABLE WEATHER CONDITIONS EXPECTED ACROSS THE LOCAL
FLYING AREA THROUGH THE FORECAST PERIOD WITH SHRA/TSRA OVER THE
LOCAL AREA TODAY. PERIODS OF MVFR OR EVEN IFR CONDITIONS ARE
EXPECTED TO CONTINUE FOR TJMZ/TJBQ/TJPS THIS MORNING AS LOWER
VISIBILITY IS EXPECTED WITH THE RAIN. VCSH/VCTS EXPECTED FOR THE
REST OF THE LOCAL TERMINALS THIS MORNING. BKN-OVC SKIES WILL
PREVAIL WITH A CEILING GENERALLY AT AROUND FL060-080...TEMPO MVFR
CEILINGS AT TIMES.
&&
.MARINE...PULSES OF NORTH NORTHWEST SWELLS OF 7 TO 8 FEET WILL
CONTINUE TO AFFECT THE ATLANTIC COASTAL WATERS THROUGH THURSDAY
AND THE MONA PASSAGE THROUGH TODAY. IN ADDITION A DEVELOPING UPPER
LOW PRESSURE JUST NORTH AND WEST OF THE REGION WILL AID IN ENHANCING
THUNDERSTORM DEVELOPMENT ACROSS THE COASTAL WATERS. SMALL CRAFT ADVISORIES
REMAIN IN EFFECT FOR THE ATLANTIC COASTAL WATERS. HAZARDOUS SURF CONDITIONS
WILL CONTINUE TO AFFECT THE ATLANTIC COASTLINES AT LEAST UNTIL THIS
EVENING. FOR THIS REASON A HIGH SURF ADVISORY AND A COASTAL FLOOD WATCH
WILL REMAIN IN EFFECT THROUGH THIS AFTERNOON. FOR ADDITIONAL INFORMATION...
PLEASE REFER TO THE LATEST MARINE WEATHER STATEMENTS AND COASTAL HAZARDS
MESSAGE...AS WELL AS THE COASTAL WATERS FORECAST ISSUED BY THE NATIONAL
WEATHER SERVICE WFO SAN JUAN PR.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 86 77 / 80 70 70 60
STT 87 77 88 79 / 70 70 70 70
NATIONAL WEATHER SERVICE SAN JUAN PR
530 AM AST WED NOV 5 2014
.SYNOPSIS...SATELLITE IMAGERY AND DOPPLER WEATHER RADAR SHOWED DEEP
LAYER MOISTURE AND WIDESPREAD CONVECTION SPREAD ACROSS THE NORTHEASTERN
CARIBBEAN AND EXTENDING SOUTHWEST INTO THE CENTRAL CARIBBEAN. THIS
AREA OF DISTURBED WEATHER IS DUE TO THE INTERACTION OF MOISTURE
CONVERGENCE ALONG A STATIONARY FRONTAL BOUNDARY/SHEARLINE SAGGING
SOUTHWARDS ACROSS HISPANIOLA AND THE MONA PASSAGE... AND A DEEPENING
AND ELONGATED TUTT WHICH EXTENDS SOUTHWARDS FROM THE WESTERN ATLANTIC
INTO THE CENTRAL CARIBBEAN. LATEST MODEL GUIDANCE CONTINUED TO SUGGEST
A TUTT LOW IS TO FORM JUST SOUTH OF HISPANIOLA BY EARLY THURSDAY THEN
SETTLE ACROSS THE CENTRAL CARIBBEAN...BEFORE SLOWLY LIFTING NORTH
NORTHEAST ACROSS THE LOCAL REGION ON FRIDAY AND SATURDAY. IN THE
MEANTIME AN INDUCED SURFACE TROUGH IS TO SLOWLY SHIFT WEST NORTHWEST
ACROSS THE REGION THROUGH THE END OF THE WEEK AN INTO THE WEEKEND.
&&
.DISCUSSION...THE ELONGATED MID TO UPPER-LEVEL TROUGH OVER THE WESTERN
ATLANTIC WILL CONTINUE TO AMPLIFY AND DIG FURTHER SOUTH INTO THE CENTRAL
CARIBBEAN TODAY. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE AFOREMENTIONED
FRONTAL BOUNDARY AND STRONG DIFFLUENT PATTERN ALOFT WILL CONTINUE TO
ENHANCE SHOWERS AND THUNDERSTORMS DEVELOPMENT ACROSS THE REGION DURING
THE DAY AND THROUGH THE END OF THE WEEK. BROAD TUTT INDUCED SURFACE
TROUGH IS TO SHIFT WEST NORTHWEST ACROSS THE REGION THROUGH THURSDAY
IN TANDEM WITH THE DEVELOPING TUTT LOW EXPECTED TO FORM AND SETTLE
ACROSS THE CENTRAL CARIBBEAN BY THURSDAY. THE TUTT LOW IS TO THEN
LIFT NORTH NORTHEAST ACROSS THE REGION BY THE END OF THE WEEK WHILE
FILLING/WEAKENING.
ALTHOUGH THERE HAS BEEN A SLIGHT DECREASE IN CONVECTION ACROSS MOST
OF THE ISLANDS DURING THE OVERNIGHT AND EARLY MORNING HOURS... THE
POTENTIAL FOR ADDITIONAL DEVELOPMENT REMAINS HIGH LATER IN THE DAY.
ANOTHER ROUND OF DEEP CONVECTION IS FORECAST...AS THE UPPER LEVEL LOW
WILL CONTINUE TO DEVELOP AND ENHANCE THUNDERSTORM DEVELOPMENT. THIS
WILL AGAIN LEAD TO PERIODS OF LOCALLY HEAVY RAINFALL AND FREQUENT
LIGHTNING ACROSS PORTIONS OF THE ISLANDS.
LATEST MODEL GUIDANCE CONTINUED TO SUGGEST MODERATE AMOUNTS OF
TROPICAL MOISTURE ADVECTION ACROSS THE REGION INTO THE UPCOMING
WEEKEND. DUE TO THIS MOIST AND VERY UNSTABLE ENVIRONMENT...THE
POTENTIAL FOR PERIODS OF LOCALLY HEAVY RAINFALL AND POSSIBLE
FLOODING WILL CONTINUE ACROSS THE ISLANDS TODAY AND POSSIBLY
THROUGH THURSDAY. IN ADDITION SOILS REMAIN VERY SATURATED AND
UNSTABLE ACROSS THE ISLANDS DUE TO RECENT RAINS. ADDITIONAL
RAINFALL WILL ONLY AGGRAVATE THE SITUATION AND LEAD TO MUDSLIDE
AND ROCKFALL IN AREAS OF STEEP TERRAIN. FOR THIS REASON THE FLASH
FLOOD WATCH WILL REMAIN IN EFFECT AT LEAST UNTIL LATER THIS
AFTERNOON...AND COULD POSSIBLY BE EXTENDED UNTIL THURSDAY. HOWEVER
WILL CONTINUE TO CLOSELY MONITOR THE ONGOING SITUATION...AND A
DECISION WILL BE MADE LATER ON IN THE DAY.
TEMPERATURES WILL BE MUCH COOLER THAN NORMAL DURING THE NEXT
COUPLE OF DAYS DUE TO THE CLOUDY SKIES AND THE OCCASIONAL RAINS.
FAIR AMOUNTS OF MOISTURE WILL CONTINUE ACROSS THE REGION THROUGH
THE WEEKEND...WITH PRECIPITABLE WATER VALUES TO RANGE BETWEEN 1.7
TO 2.0 INCHES OR SO. LOW LEVEL WINDS WILL REMAIN FAIRLY LIGHT BUT
SOUTHERLY TODAY...GRADUALLY BECOME MORE SOUTHEASTERLY THURSDAY AND
THROUGH THE WEEKEND. A SOMEWHAT DRIER AIR MASS IS EXPECTED TO FILTER
IN BY EARLY NEXT WEEK WHEN THE REGION RETURNS TO A MORE EASTERLY
WIND FLOW AND HIGH PRESSURE BUILDS ALOFT.
&&
.AVIATION...UNSTABLE WEATHER CONDITIONS EXPECTED ACROSS THE LOCAL
FLYING AREA THROUGH THE FORECAST PERIOD WITH SHRA/TSRA OVER THE
LOCAL AREA TODAY. PERIODS OF MVFR OR EVEN IFR CONDITIONS ARE
EXPECTED TO CONTINUE FOR TJMZ/TJBQ/TJPS THIS MORNING AS LOWER
VISIBILITY IS EXPECTED WITH THE RAIN. VCSH/VCTS EXPECTED FOR THE
REST OF THE LOCAL TERMINALS THIS MORNING. BKN-OVC SKIES WILL
PREVAIL WITH A CEILING GENERALLY AT AROUND FL060-080...TEMPO MVFR
CEILINGS AT TIMES.
&&
.MARINE...PULSES OF NORTH NORTHWEST SWELLS OF 7 TO 8 FEET WILL
CONTINUE TO AFFECT THE ATLANTIC COASTAL WATERS THROUGH THURSDAY
AND THE MONA PASSAGE THROUGH TODAY. IN ADDITION A DEVELOPING UPPER
LOW PRESSURE JUST NORTH AND WEST OF THE REGION WILL AID IN ENHANCING
THUNDERSTORM DEVELOPMENT ACROSS THE COASTAL WATERS. SMALL CRAFT ADVISORIES
REMAIN IN EFFECT FOR THE ATLANTIC COASTAL WATERS. HAZARDOUS SURF CONDITIONS
WILL CONTINUE TO AFFECT THE ATLANTIC COASTLINES AT LEAST UNTIL THIS
EVENING. FOR THIS REASON A HIGH SURF ADVISORY AND A COASTAL FLOOD WATCH
WILL REMAIN IN EFFECT THROUGH THIS AFTERNOON. FOR ADDITIONAL INFORMATION...
PLEASE REFER TO THE LATEST MARINE WEATHER STATEMENTS AND COASTAL HAZARDS
MESSAGE...AS WELL AS THE COASTAL WATERS FORECAST ISSUED BY THE NATIONAL
WEATHER SERVICE WFO SAN JUAN PR.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 86 75 86 77 / 80 70 70 60
STT 87 77 88 79 / 70 70 70 70