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 291114 CCA
AFDSJU

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
714 AM AST FRI AUG 29 2014

.SYNOPSIS...RETROGRESSING TUTT LOW JUST NORTH OF PUERTO RICO WILL
CONTINUE TO MOVE WEST NORTHWEST WHILE GRADUALLY FILLING. AT LOW
LEVELS TUTT INDUCED LOW TO MID LEVEL TROUGH AND A TROPICAL WAVE
WILL CONTINUE TO ENTER AND MOVE ACROSS THE EASTERN CARIBBEAN TODAY
THROUGH SATURDAY. SURFACE HIGH PRESSURE RIDGE EXTENDING ACROSS THE
NORTHEASTERN CARIBBEAN FROM THE CENTRAL ATLANTIC WILL WEAKEN
THROUGH SATURDAY...AS IT PULLS FARTHER NORTH AND EAST ACROSS THE
ATLANTIC. THIS WILL HELP TO LOOSEN THE LOCAL PRESSURE
GRADIENT...WHICH IN TURN WILL RESULT IN A GRADUAL DECREASING OF
THE LOCAL TRADE WINDS OVER THE NEXT FEW DAYS AND THROUGH THE
UPCOMING WEEKEND.

&&

.DISCUSSION...BROAD SWATH OF ITCZ MOISTURE WILL BE LIFTED NORTHWARDS
ACROSS THE REGION AS LOW LEVEL TROUGH AND TROPICAL WAVE WILL CONTINUE
TO QUICKLY MOVE WESTWARD ACROSS EASTERN CARIBBEAN OVER THE NEXT
COUPLE OF DAYS. THE PROXIMITY OF THE TUTT LOW WILL HELP TO ENHANCE
EARLY MORNING AND AFTERNOON CONVECTION ACROSS THE COASTAL WATERS
AND LOCAL ISLANDS TODAY. WITH FAIRLY LIGHT WINDS...LOCAL SEA BREEZE
CONVERGENCE SHOULD ALSO AID IN AFTERNOON SHOWERS AND THUNDERSTORM
DEVELOPMENT ESPECIALLY ACROSS PARTS OF THE INTERIOR AND WEST SECTIONS
OF PUERTO RICO.

FAIR AMOUNTS OF TROPICAL MOISTURE ADVECTION IS FORECAST TO CONTINUE
OVER THE FORECAST AREA THROUGH AT LEAST THE EARLY PART OF THE
OF THE WEEKEND WITH THE PASSAGE OF A TROPICAL WAVE. THIS FAIRLY
MOIST ENVIRONMENT WILL THEREFORE INCREASE THE CHANCES FOR SHOWERS
AND THUNDERSTORM ACTIVITY THROUGH AT LEAST SATURDAY AND POSSIBLE
ON SUNDAY. LATEST GFS COMPUTER MODEL GUIDANCE CONTINUED TO SUGGEST
INCREASING THETA-E VALUES UP TO NEAR 338K WITH PWAT VALUES TO RANGE
BETWEEN 1.8 TO NEAR 2.0 INCHES. THEREFORE FOR THE LABOR DAY WEEKEND
EXPECT A MIXTURE OF SUNSHINE AND CLOUDS WITH PERIODS OF EARLY MORNING
AND AFTERNOON SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BE HEAVY
AT TIMES ESPECIALLY LATER TODAY AND ON SATURDAY. SO FAR LOOKING FOR
GRADUALLY IMPROVING CONDITIONS ON SUNDAY AND MONDAY.

&&

.AVIATION...MOSTLY VFR CONDITIONS ARE EXPECTED ACROSS THE LOCAL
FLYING AREA THIS MORNING WITH PASSING SHOWERS WITH BRIEF PERIODS OF
MVFR CONDITIONS ACROSS TIST AND TISX. SFC WINDS WILL BE MAINLY LIGHT
AND VARIABLE. AFTER 29/13Z WINDS WILL REMAIN EASTERLY AT AROUND
10 KNOTS WITH AFTERNOON SHRA/TSRA EXPECTED ACROSS THE WESTERN
INTERIOR OF PR...LIKELY AFFECTING AREAS IN AND AROUND TJPS...TJMZ...
AND TJBQ.

&&

.MARINE...WINDS AND SEAS ACROSS THE LOCAL WATERS WILL CONTINUE TO
SUBSIDE TODAY AND THROUGH THE UPCOMING WEEKEND. HOWEVER...SMALL
CRAFT OPERATORS SHOULD CONTINUE EXERCISE CAUTION ACROSS THE OFFSHORE
ATLANTIC DUE TO SEAS OF 6 FEET OR SO. ELSEWHERE SEAS WILL BE 5
FEET OR LESS AND WINDS 17 KNOTS OR LESS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  89  78  89  78 /  50  50  50  50
STT  87  78  89  79 /  40  50  50  50

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
COASTAL WATERS...NONE.
&&

$$

72/09




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