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 011020
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
620 AM AST WED APR 1 2015

.SYNOPSIS...FLAT UPPER LEVEL RIDGE WILL CONTINUE OVER THE REGION
TODAY...COLLAPSING BY THURSDAY...AS AN UPPER LEVEL TROUGH...NOW
OVER THE WESTERN ATLANTIC...AMPLIFIES OVER THE REGION THURSDAY
INTO THE WEEKEND.

AT THE SURFACE LEVEL...A STATIONARY FRONTAL BOUNDARY IS OFF TO THE
NORTH OF THE LOCAL AREA AND WILL CONTINUE DURING THE NEXT FEW
DAYS. A SURFACE HIGH PRESSURES WILL MIGRATE EASTWARD ACROSS THE
WESTERN ATLANTIC AND INTO THE CENTRAL ATLANTIC...TIGHTENING THE
LOCAL PRESSURE GRADIENT THURSDAY THROUGH SUNDAY. LOCAL TRADE WINDS
WILL INCREASE AFTER THURSDAY AND DURING THE UPCOMING WEEKEND.

&&

.DISCUSSION...SATELLITE IMAGES AND MODEL GUIDANCE ARE INDICATING
A HUMID AIR MASS APPROACHING THE ISLANDS. THIS AIR MASS WILL REACH
THE CWA TODAY...TO PRODUCE AN INCREMENT IN SHOWER ACTIVITY. THIS
MORNING... SHOWERS WILL FOCUS ACROSS THE EASTERN HALF OF PUERTO
RICO AND THE US VIRGIN ISLANDS. DURING THE AFTERNOON...THE
COMBINATION OF THE AVAILABLE MOISTURE AND LOCAL EFFECTS WILL
ENHANCE THE FORMATION OF SHOWERS MAINLY ACROSS THE INTERIOR AND
WESTERN PUERTO RICO. ALSO SHOWERS MAY FORM IN THE WAKE OF THE
ISLANDS OF VIEQUES...CULEBRA...ST THOMAS AND ST CROIX.

INCLEMENT WEATHER IS EXPECTED AS THE UPPER LEVEL RIDGE COLLAPSE
AND AN UPPER LEVEL TROUGH BUILDS OVER THE REGION THURSDAY INTO THE
WEEKEND. THEREFORE...POTENTIAL FOR MODERATE TO HEAVY SHOWERS AND
T-STORMS EXIST DURING THIS DAYS UNDER IMPROVING JET DYNAMICS. WX
CONDITIONS BEGIN TO IMPROVE ON SUNDAY.

&&

.AVIATION...MAINLY VFR CONDS NEXT 24 HOURS ACROSS ALL TAF SITES.
BRIEF PASSING VCSH MAY AFFECT TIST/TISX/TNCM/TKPK BFR 01/12Z. THEN
AFT 01/18Z...SHRA WILL DEVELOP IN AND AROUND TJBQ/TJMZ...TO CREATE
AREAS OF MVFR CONDS AND MTN OBSCURATIONS. WINDS BLO FL090 EAST TO
SOUTHEAST WINDS WILL CONTINUE AT 10 TO 15 KT WITH SOME HIGHER GUSTS
...ESPECIALLY IN SEA BREEZE VARIATIONS AFTER 14Z.

&&

.MARINE...ACROSS THE ATLANTIC WATERS CAN EXPECT SEAS BETWEEN 5-6
FT. THEREFORE...SMALL CRAFT OPERATORS SHOULD EXERCISE CAUTION
ACROSS THESE WATERS. ON THE OTHER HAND...ACROSS THE CARIBBEAN
WATERS EXPECTED SEAS BETWEEN 3 AND 5 FEET. WINDS WILL CONTINUE
FROM THE EAST UP TO 15 KT. TRADE WINDS ARE EXPECTED TO INCREASE
AFTER WEDNESDAY AS A HIGH PRESSURE MOVES EASTWARD ACROSS THE
ATLANTIC WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  86  75  85  75 /  30  40  40  30
STT  82  75  83  74 /  40  40  40  20

&&

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

$$

12/27


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