Post by Deleted on Jul 8, 2013 6:59:48 GMT -6
Discussion by HPC for PR.
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
637 AM EDT MON JUL 08 2013
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. MID UPPER
RIDGE EXTENDS FROM THE NORTH ATLANTIC ACROSS PUERTO RICO/USVI AND
INTO THE NORTHERN CARIBBEAN. TO THE WEST... DEEP TUTT LOW CENTERS
OVER THE CENTRAL BAHAMAS WHILE RETROGRESSING. AT LOW LEVELS WINDS
WERE FROM THE EAST-SOUTHEAST PEAKING AT 25KT AT 925 HPA. SAN JUAN
SOUNDING SHOWS SUBSIDENCE INVERSION ESTABLISHED AT 800 HPA WHILE A
MUCH DRIER LAYER WAS PRESENT ABOVE 550 HPA. WIDELY SCATTERED
CONVECTION WAS OCCURRING TO THE SOUTH OF PUERTO RICO MOVING
WEST-NORTHWESTWARD...WHILE QUIET CONDITIONS WERE DOMINATING THE
ISLANDS. THIS CONVECTION WAS ASSOCIATED WITH A TROPICAL WAVE THAT
CENTERED AT 61W AT 00Z.
MODELS SHOW STRONGEST CONVECTION IN ASSOCIATION WITH THIS WAVE
DURING THE DAY TODAY...WHILE STAYING MOSTLY TO THE SOUTH OF THE
FORECAST DOMAIN OVER THE OPEN WATERS OF THE CARIBBEAN. CONVECTIVE
INSTABILITY WILL PEAK THROUGH 18-20 UTC TODAY TO RAPIDLY DECREASE
INTO THE EVENING. THIS COULD ENHANCE MARGINALLY DIURNAL CONVECTION
TODAY. EXPECTING GENERALLY LIGHT ACCUMULATIONS GENERALLY IN THE
ORDER OF 05-10MM/DAY AND ISOLATED MAXIMA OF 15-20MM.
SYSTEM OF CONCERN IS NOW TROPICAL STORM CHANTAL...FORECAST TO PASS
SOUTH OF THE ISLANDS EARLY ON WEDSNESDAY (SEE NHC FOR OFFICIAL
FORECAST TRACK AND INTENSITY). CHANGES IN STORM TRACK AND
INTENSITY COULD GREATLY MODULATE THE AMOUNT OF RAINFALL IN PUERTO
RICO AND THE USVI...ESPECIALLY SINCE CHANTAL IS A SMALL CYCLONE.
MODELS ARE AGREEING IN HEAVIER PRECIPITATION AFFECTING HISPANIOLA
LATER ON WEDNESDAY...WHILE RESOLVING ONLY MODERATE ACCUMULATIONS
OVER PUERTO RICO/USVI. ALL LOW-RESOLUTION GLOBAL MODELS ARE
AGREEING IN TOTAL EVENT ACCUMULATIONS IN THE ORDER OF
20-40MM...WHILE THE HIGHER RESOLUTION GFS ADDS UP TO 25-50MM. THE
HIGHER RESOLUTION MODELS ARE NOT AVAILABLE YET. ALTHOUGH THE
MODELS AGREE IN AMOUNTS...IT APPEARS AS THEY ARE DOWNPLAYING THE
POTENTIAL FOR RAINFALL WITH THIS SYSTEM. WE ARE LEANING TO A
WETTER SOLUTION...WITH TOTAL EVENT ACCUMULATIONS IN THE ORDER OF
20-40MM AND MAXIMA OF 50-100MM...WITH ISOLATED HIGHER AMOUNTS IN
INTERACTION WITH OROGRAPHY. AGAIN...IT ALL DEPENDS ON THE EXACT
TRACK OF CHANTAL WHICH IS CURRENTLY A SMALL CYCLONE. THIS CAN
CAUSE LARGE DIFFERENCES IN RAINFALL OVER A SHORT DISTANCE.
STILL...IT SEEMS THAT SOUTHEASTERN/EASTERN PUERTO RICO MAY RECEIVE
THE HIGHEST AMOUNTS IF CURRENT FORECAST TRACK VERIFIES...WITH
HIGHEST POTENTIAL FOR HEAVY SQUALLS DEVELOPING LATE ON TUESDAY
NIGHT THROUGH EARLY WEDNESDAY AND WANING DURING THE DAY ON
WEDNESDAY.
MCKENZIE...BDM (BAHAMAS)
ROBINSON...MSJ (JAMAICA)
GALVEZ...WPC (USA)
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
637 AM EDT MON JUL 08 2013
PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI. MID UPPER
RIDGE EXTENDS FROM THE NORTH ATLANTIC ACROSS PUERTO RICO/USVI AND
INTO THE NORTHERN CARIBBEAN. TO THE WEST... DEEP TUTT LOW CENTERS
OVER THE CENTRAL BAHAMAS WHILE RETROGRESSING. AT LOW LEVELS WINDS
WERE FROM THE EAST-SOUTHEAST PEAKING AT 25KT AT 925 HPA. SAN JUAN
SOUNDING SHOWS SUBSIDENCE INVERSION ESTABLISHED AT 800 HPA WHILE A
MUCH DRIER LAYER WAS PRESENT ABOVE 550 HPA. WIDELY SCATTERED
CONVECTION WAS OCCURRING TO THE SOUTH OF PUERTO RICO MOVING
WEST-NORTHWESTWARD...WHILE QUIET CONDITIONS WERE DOMINATING THE
ISLANDS. THIS CONVECTION WAS ASSOCIATED WITH A TROPICAL WAVE THAT
CENTERED AT 61W AT 00Z.
MODELS SHOW STRONGEST CONVECTION IN ASSOCIATION WITH THIS WAVE
DURING THE DAY TODAY...WHILE STAYING MOSTLY TO THE SOUTH OF THE
FORECAST DOMAIN OVER THE OPEN WATERS OF THE CARIBBEAN. CONVECTIVE
INSTABILITY WILL PEAK THROUGH 18-20 UTC TODAY TO RAPIDLY DECREASE
INTO THE EVENING. THIS COULD ENHANCE MARGINALLY DIURNAL CONVECTION
TODAY. EXPECTING GENERALLY LIGHT ACCUMULATIONS GENERALLY IN THE
ORDER OF 05-10MM/DAY AND ISOLATED MAXIMA OF 15-20MM.
SYSTEM OF CONCERN IS NOW TROPICAL STORM CHANTAL...FORECAST TO PASS
SOUTH OF THE ISLANDS EARLY ON WEDSNESDAY (SEE NHC FOR OFFICIAL
FORECAST TRACK AND INTENSITY). CHANGES IN STORM TRACK AND
INTENSITY COULD GREATLY MODULATE THE AMOUNT OF RAINFALL IN PUERTO
RICO AND THE USVI...ESPECIALLY SINCE CHANTAL IS A SMALL CYCLONE.
MODELS ARE AGREEING IN HEAVIER PRECIPITATION AFFECTING HISPANIOLA
LATER ON WEDNESDAY...WHILE RESOLVING ONLY MODERATE ACCUMULATIONS
OVER PUERTO RICO/USVI. ALL LOW-RESOLUTION GLOBAL MODELS ARE
AGREEING IN TOTAL EVENT ACCUMULATIONS IN THE ORDER OF
20-40MM...WHILE THE HIGHER RESOLUTION GFS ADDS UP TO 25-50MM. THE
HIGHER RESOLUTION MODELS ARE NOT AVAILABLE YET. ALTHOUGH THE
MODELS AGREE IN AMOUNTS...IT APPEARS AS THEY ARE DOWNPLAYING THE
POTENTIAL FOR RAINFALL WITH THIS SYSTEM. WE ARE LEANING TO A
WETTER SOLUTION...WITH TOTAL EVENT ACCUMULATIONS IN THE ORDER OF
20-40MM AND MAXIMA OF 50-100MM...WITH ISOLATED HIGHER AMOUNTS IN
INTERACTION WITH OROGRAPHY. AGAIN...IT ALL DEPENDS ON THE EXACT
TRACK OF CHANTAL WHICH IS CURRENTLY A SMALL CYCLONE. THIS CAN
CAUSE LARGE DIFFERENCES IN RAINFALL OVER A SHORT DISTANCE.
STILL...IT SEEMS THAT SOUTHEASTERN/EASTERN PUERTO RICO MAY RECEIVE
THE HIGHEST AMOUNTS IF CURRENT FORECAST TRACK VERIFIES...WITH
HIGHEST POTENTIAL FOR HEAVY SQUALLS DEVELOPING LATE ON TUESDAY
NIGHT THROUGH EARLY WEDNESDAY AND WANING DURING THE DAY ON
WEDNESDAY.
MCKENZIE...BDM (BAHAMAS)
ROBINSON...MSJ (JAMAICA)
GALVEZ...WPC (USA)