Area Forecast Discussion
Issued by NWS San Juan, PR

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXCA62 TJSJ 300136
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
936 PM AST SAT AUG 29 2015

.UPDATE...
TUTT INDUCE EASTERLY WAVE WILL CONTINUE TO MOVE ACROSS THE NORTHEASTERN
CARIBBEAN OVERNIGHT THROUGH SUNDAY. AS PREVIOUSLY MENTIONED...THIS
WILL BRING AN INCREASE IN LOW LEVEL MOISTURE...WHICH WAS NOW
CROSSING PORTIONS OF THE LESSER ANTILLES. DOPPLER WEATHER RADAR
AND SATELLITE SHOWED ISOLATED SHOWERS MOVING ACROSS THE COASTAL
WATERS WITH A FEW MOVING ACROSS PORTIONS OF EASTERN PUERTO RICO
AND JUST OFF SHORE OF THE U.S. VIRGIN ISLANDS. STILL EXPECT A
GRADUAL INCREASE IN SHOWER ACTIVITY AND POSSIBLY ISOLATED THUNDERSTORMS
ACROSS PORTIONS OF THE COASTAL WATERS BY EARLY MORNING...AS THE
WAVE MOVES ACROSS THE EASTERN CARIBBEAN ON SUNDAY. NO SIGNIFICANT
CHANGES MADE TO THE INHERITED FORECAST PACKAGE AT THIS TIME. DID
HOWEVER UPDATE THE SHORT/LONG TERM WINDS AND SEAS BASED ON LATEST
MODEL GUIDANCE...AND PRESENT WEATHER CONDITIONS. RECENT MODEL GUIDANCE
STILL SUGGEST ANOTHER TROPICAL WAVE FORECAST TO MOVE ACROSS THE REGION
TUESDAY THROUGH WEDNESDAY OF NEXT WEEK.

&&

.AVIATION UPDATE...MOISTURE FROM A TROP WAVE WL CONT TO MOVE WWARD
INTO THE NERN CARIBBEAN BRINGING PDS OF MVFR CONDS TO TNCM AND
TKPK IN SHRA AND LOW CIGS TIL ABT 30/18Z. SHRA WILL MOVE INTO THE
WATERS ARND TIST AND TISX BY 30/03Z WITH MVFR CONDS PSBL FOR BRIEF
PDS. EXPECT MTN OBSCURATIONS TO CONT IN ERN PR TIL AFT 30/20Z.
SHRA/TSRA TO DVLP OVR WRN AND INTERIOR PR BY 30/17Z AND PERSIST
UNTIL ARND 31/00Z WITH MTN OBSCURATIONS AND PDS OF MVFR AT TJMZ
AND TJBQ. WINDS ALF ELY 15 TO 25 KT BCMG SE AFT 30/12Z. SFC GUSTS
TO 28 KT AFT 30/14Z.

&&

.MARINE UPDATE...WINDS OF 10-20 KNOTS AND SEAS OF 6 FEET OR LESS
WILL PREVAIL OVERNIGHT. SMALL CRAFT OPERATORS SHOULD EXERCISE
CAUTION DUE TO CHOPPY CONDITIONS ACROSS MOST OF THE COASTAL WATERS.
NO CHANGE TO PREVIOUS MARINE DISCUSSION. PLEASE REFER TO THE LATEST
COASTAL WATERS FORECAST ISSUED BY THE NATIONAL WEATHER SERVICE WFO
SAN JUAN PR.

&&

.PREV DISCUSSION... /ISSUED 233 PM AST SAT AUG 29 2015/

SYNOPSIS...HIGH PRESSURE NORTH OF THE ISLANDS WILL KEEP A
MODERATE EASTERLY WIND FLOW FOR THE NEXT SEVERAL DAYS. TWO
TROPICAL WAVES ARE EXPECTED TO AFFECT THE REGION. FIRST TROPICAL
WAVE WILL AFFECT THE REGION ON SUNDAY AND THE NEXT ONE WILL PASS
THROUGH THE AREA TUESDAY INTO WEDNESDAY.

DISCUSSION...A STABLE AIR MASS MOVED ACROSS THE REGION
TODAY..LIMITING THE SHOWER ACTIVITY ACROSS THE REGION. IN
FACT...VERY LITTLE ACTIVITY WAS OBSERVED.

A WEAK TROPICAL WAVE IS EXPECTED TO MOVE OVER THE REGION EARLY
SUNDAY MORNING...BRINGING AN INCREASE IN LOW LEVEL MOISTURE TO THE
LOCAL AREA. GFS MODEL GUIDANCE SUGGESTS THAT THE PWAT VALUES WILL
INCREASE UP TO 2.2 INCHES BUT THE BULK OF THE MOISTURE ASSOCIATED
WITH THE WAVE IS EXPECTED TO REMAINS SOUTH OF THE LOCAL ISLANDS
ACROSS THE CARIBBEAN WATERS. AFTER THE PASSAGE OF THIS
WAVE...RELATIVELY DRY WEATHER CONDITIONS ARE EXPECTED ON MONDAY.
ANOTHER TROPICAL WAVE IS EXPECTED TO AFFECT THE LOCAL REGION BY
TUESDAY. THIS WAVE WILL BRING BETTER MOISTURE TO THE LOCAL AREA
COMPARED TO THE WAVE WHICH WILL AFFECT US TOMORROW. IN THE LONG
TERM..AT THIS TIME...NO OTHER SIGNIFICANT WEATHER EVENTS ARE
FORECAST TO AFFECT THE LOCAL REGION.

AVIATION...A TROPICAL WAVE WILL CONTINUE TO MOVE WESTWARD
ACROSS THE LESSER ANTILLES THIS EVENING AND ACROSS THE USVI AND
PUERTO RICO OVERNIGHT AND EARLY SUNDAY. THIS FEATURE WILL PRODUCE
BRIEF PERIODS OF MVFR CONDITIONS ACROSS TKPK AND TNCM AFTER
29/22Z...ACROSS TISX AND TIST AFTER 30/03Z AND ACROSS TJSJ AND TJPS
AFTER 30/06Z. THE MOISTURE ASSOCIATED WITH THE WAVE IS EXPECTED
PRODUCE MVFR OR EVEN IFR CONDITIONS OVER TJMZ AND TJBQ IN SHRA AND
TSRA FROM 30/17Z TO 30/21Z. WINDS WERE MOSTLY FROM THE EAST
SOUTHEAST AT 10 TO 15 MPH WITH SOME HIGHER GUSTS.

MARINE...SEAS WILL REMAIN CHOPPY THE REST OF THIS AFTERNOON AND
TONIGHT WITH WINDS OF 18 KNOTS AND HIGHER GUSTS. SEAS WILL
GRADUALLY IMPROVE TONIGHT BUT THEY STILL ARE UP TO 6 FEET. SMALL
CRAFT SHOULD EXERCISE CAUTION. A HIGH RISK OF RIP CURRENTS WILL
REMAIN ACROSS MANY OF THE LOCAL BEACHES...PLEASE REFER TO THE RIP
CURRENT STATEMENT FOR MORE DETAILS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  82  89  82  90 /  40  40  10  30
STT  80  89  80  90 /  50  50  30  30

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
AM...NONE.
&&

$$

12/09



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.