Area Forecast Discussion
Issued by NWS San Juan, PR

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FXCA62 TJSJ 221602
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1202 PM AST TUE JUL 22 2014

.UPDATE...
WEAK EASTERLY PERTURBATION PRESENTLY MOVING ACROSS THE REGION
WAS TRANSPORTING SMALL PATCHES OF LOW LEVEL MOISTURE AND EARLY
MORNING SHOWERS TO THE REGION. EXPECT SUFFICIENT MOISTURE ADVECTION
DURING THE REST OF THE DAY FOR SOME LOCALLY AND DIURNALLY INDUCED
AFTERNOON CONVECTION MAINLY ACROSS PARTS OF THE INTERIOR AND NORTH
SECTIONS OF PUERTO RICO. ONLY ISOLATED SHOWERS IF ANY EXPECTED
OVER THE VIRGIN ISLANDS...AS PARTLY CLOUDY TO MOSTLY SUNNY SKIES
SHOULD PREVAIL.

AS FAR AS TROPICAL DEPRESSION TWO...BASED ON THE LATEST INFO FROM
THE NATIONAL HURRICANE CENTER IN MIAMI...AT 1100 AM AST...THE DEPRESSION
WAS LOCATED NEAR LATITUDE 12.6 N...LONGITUDE 48.0 WEST...MOVING WEST
NEAR 17 MPH. A SLOW WEST NORTHWESTWARD MOTION IS EXPECTED OVER THE
NEXT FEW DAYS. HOWEVER AT THIS TIME...LITTLE CHANGE IS EXPECTED IN
STRENGTH AS THIS FEATURE WILL ENTER A MORE HOSTILE ENVIRONMENT LESS
CONDUCIVE FOR DEVELOPMENT. THIS PRESENT SCENARIO...SHOULD THEREFORE
INHIBIT FURTHER INTENSIFICATION AND THE DEPRESSION IS STILL EXPECTED
TO WEAKEN TO A REMNANT LOW BY LATE WEDNESDAY...THEN INTO A TROUGH
OF LOW PRESSURE BY THURSDAY...AS IT APPROACHES AND MOVES ACROSS THE
REGION. NO MAJOR CHANGES MADE TO THE INHERITED SHORT TERM FORECAST
PACKAGE AT THIS TIME.

&&

.AVIATION UPDATE...NO CHANGE TO PREVIOUS AVN DISCUSSION.


&&

.MARINE UPDATE...SEAS WERE 3 TO 5 FEET BASED OF THE LATEST OBSERVATIONS
WITH WINDS OF 19 KNOTS OR LESS ACROSS MOST OF THE REGIONAL WATERS.
A SLIGHT INCREASE IN WINDS AND SEAS IS EXPECTED DURING THE LATTER
PART OF THE WEEK AS THE DEPRESSION OR ITS REMNANTS MOVE ACROSS THE
EASTERN CARIBBEAN WATERS. DURING THAT TIME AN INCREASE IN THUNDERSTORM
ACTIVITY WITH AREAS OF LOCALLY HEAVY RAINFALL AND GUSTY WINDS WILL BE
POSSIBLE. STAY TUNED TO LATEST COASTAL WATERS FORECAST ISSUED BY WFO
SAN JUAN PUERTO RICO.

&&

.PREV DISCUSSION... /ISSUED 454 AM AST TUE JUL 22 2014/

SYNOPSIS...SURFACE HIGH PRESSURE ACROSS THE CENTRAL ATLANTIC WILL
CONTINUE TO MAINTAIN MODERATE TO FRESH TRADE WIND FLOW ACROSS THE
LOCAL AREA NEXT SEVERAL DAYS. TROPICAL DEPRESSION TWO IS FORECAST
TO WEAKEN NEXT 48 HOURS. REMNANTS OF THIS LOW PRESSURE SYSTEM WILL
APPROACH THE LOCAL AREA FRIDAY.

DISCUSSION...SCATTERED SHOWERS WERE NOTED OVERNIGHT OVER THE
LOCAL COASTAL WATERS...WITH SOME AFFECTING PUERTO RICO. THESE
SHOWERS WERE MOVING QUICKLY WESTWARD. THEREFORE...RAINFALL
ACCUMULATION WAS NOT SIGNIFICANT. LATEST SATELLITE IMAGES SHOWED
PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE TRADE WIND FLOW
APPROACHING THE LOCAL AREA FROM THE EAST. SCATTERED SHOWERS ARE
EXPECTED TO CONTINUE TO AFFECT THE LOCAL ISLANDS THIS MORNING INTO
THE AFTERNOON HOURS. ONCE AGAIN...AVAILABLE MOISTURE...WILL
COMBINE WITH LOCAL EFFECTS TO PRODUCE SCATTERED SHOWERS WITH
ISOLATED THUNDERSTORM THIS AFTERNOON...MAINLY OVER THE WESTERN
INTERIOR AND NORTHWEST SECTIONS OF PUERTO RICO.

THE MAIN WEATHER FEATURE THIS MORNING IS TROPICAL DEPRESSION TWO
WHICH WAS LOCATED AROUND 1400 MILES SOUTHEAST OF PUERTO RICO. THIS
SYSTEM WILL ENCOUNTER UNFAVORABLE ATMOSPHERIC CONDITIONS NEXT
COUPLE OF DAYS AS IT MOVES WEST NORTHWEST. THEREFORE...THE
OFFICIAL FORECAST FROM THE NATIONAL HURRICANE CENTER INDICATES THIS
SYSTEM WILL WEAKEN NEXT 48 HOURS AND IS FORECAST TO BECOME A
TROUGH OF LOW PRESSURE BY THE TIME IT REACHES THE LESSER
ANTILLES.

FOR OUR AREA...STILL EXPECTED A SIGNIFICANT INCREASE IN MOISTURE
ASSOCIATED WITH THIS SYSTEM...AS PASSES NEAR OR OVER THE LOCAL AREA
BY FRIDAY. LATEST 22/00Z GFS COMPUTER MODEL RUN SHOWED
PRECIPITABLE WATER ABOVE 2.0 INCHES OVER THE LOCAL AREA WITH DEEP
TROPICAL MOISTURE AFFECTING THE LOCAL AREA THROUGH SATURDAY.
THEREFORE...AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY CAN BE
EXPECTED BOTH DAYS AS THE REMNANTS OF THIS SYSTEM MOVE ACROSS THE
REGION. STAY TUNED FOR LATEST INFORMATION ON TROPICAL DEPRESSION
TWO.

AVIATION...SCT SHRA MAINLY OFFSHORE THIS MRNG AND AGAIN TONITE AS
MOISTURE DEEPENS BLO 10 KFT...BUT MVFR WL BE BRIEF/ISOLD AT
TJSJ/TIST/TISX/TNCM/TKPK. SCT SHRA/ISOLD TSRA WEST PR THIS AFT AND
AGAIN WED AFT WI LCL MVFR AND OBSCD MTNS. WIND BLO FL150 ESE 12-24
KT BCMG E LATE TUE NITE.

MARINE...SEAS UP TO 5 FEET AND WINDS UP TO 19 KNOTS ARE EXPECTED
TO PREVAIL ACROSS THE COASTAL WATERS TODAY. SMALL CRAFT SHOULD
EXERCISE CAUTION ACROSS MOST COASTAL WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  88  79  92  79 /  40  20  20  10
STT  89  79  91  81 /  50  30  30  20

&&

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

$$

09/25




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