San Juan Discussion

[chadtm80]

000
FXCA62 TJSJ 251444
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1100 AM AST MON AUG 25 2003

SO FAR I SEE NO REASON TO AMEND. WILL ADD THE FOLLOWING. 12Z
SOUNDING FOR SAN JUAN AND ST MARTIN REVEALED A VERY UNSTABLE AND
MOIST AIRMASS. 2.29 AND 2.42 INCHES OF PRECIPITABLE WATER WERE SHOWN
FOR SAN JUAN AND ST MARTIN RESPECTIVELY. SATELLITE PICTURES ALSO
SHOWED CONSIDERABLE CLOUDS AND WITH THUNDERSTORMS EMBEDDED AND
DOPPLER RADAR SHOWED SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS OVER THE ATLANTIC...CARIBBEAN WATERS...AND AFFECTING
THE U.S. VIRGIN ISLANDS AND PUERTO RICO. MODEL GUIDANCE IN GENERAL
AGREEMENT WITH THIS SUGGESTING THE MORE SIGNIFICANT MOISTURE SURGE
ASSOCIATED TO THE TROPICAL WAVE PASSING THROUGH TONIGHT. A DECREASE
IN THE SPEED OF THE LOW LEVEL FLOW IMPLIES HIGHER AND SIGNIFICANT
RAINFALL AMOUNTS TONIGHT INTO TUESDAY MORNING. /RIVERA

PLEASE PREVIOUS REASONING BELOW.


STRONG AND LARGE TROPICAL WAVE...WITH AXIS LOCATED OVER THE LESSER
ANTILLES EARLY THIS MORNING...WILL MOVE WEST NORTHWEST AND THEN
NORTHWEST PASSING ACROSS THE U.S. VIRGIN ISLANDS AND PUERTO RICO
THIS AFTERNOON THROUGH TUESDAY AND THEN AWAY FROM THE LOCAL AREA
TUESDAY NIGHT AND WEDNESDAY. 06Z CIMMS ANALYSES INDICATING DECENT
UPPER LEVEL DIVERGENCE OVER WAVE...WITH FAIRLY LOW SHEAR AND GOOD
ANTICYCLONIC OUTFLOW IN ITS VICINITY. 00Z TJSJ SOUNDING SHOWED SOME
SOUTHWEST AND WEST UPPER LEVEL FLOW LOCALLY...BUT MOSTLY 11 KNOTS OR
LESS. HOWEVER...SATELLITE DATA APPEARS TO INDICATE MUCH STRONGER
UPPER LEVEL SOUTHWEST TO WEST WIND NORTH OF 19 OR 20 DEGREES NORTH.

00Z GLOBAL MODEL SOLUTIONS QUITE SIMILAR WITH THIS WAVE...BRINGING
DEEP MOISTURE (850-700 MB THETA E)...INCREASING H5 VORTICITY AND
DECENT H7 LIFT ACROSS FA...WHICH SHOULD RESULT IN INCREASING AMOUNTS
OF CLOUDINESS...SHOWERS AND THUNDERSTORMS FOR THE LOCAL ISLANDS...
BEGINNING LATER TODAY AND THEN LIKELY CONTINUING THROUGH MUCH OF
TUESDAY. POTENTIAL CERTAINLY EXISTS FOR AT LEAST SOME LOCALIZED
HEAVY RAINFALL AND RESULTANT FLOODING...ESPECIALLY GIVEN ANTECEDENT
WET GROUNDS IN SOME PARTS OF PUERTO RICO. NO FLASH FLOOD WATCH AT
THIS TIME...BUT DAY SHIFT MAY NEED TO GO AHEAD WITH ONE...AS TIMING
OF BEST PRECIPITATION AND AREAL COVERAGE OF MOST LIKELY TROUBLE
SPOTS BECOME MORE DEFINED.

FOR COASTAL WATERS...GENERALLY EXPECT WIND OF 19 KNOTS OR LESS AND
SEAS MOSTLY 5 FEET OR LESS THROUGH WEDNESDAY. AS WAVE AXIS
APPROACHES AND THEN PASSES...WIND DIRECTION SHOULD BE SHIFTING FROM
EAST NORTHEAST TODAY THROUGH EARLY THIS EVENING...TO MORE EAST
TONIGHT AND THEN EAST SOUTHEAST AND SOUTHEAST TUESDAY AND TUESDAY
NIGHT...THEN BACK TO A MORE EAST DIRECTION SOMETIME WEDNESDAY. HAVE
A PRECAUTIONARY STATEMENT IN EFFECT FOR THE ATLANTIC OFF SHORE
WATERS AND ALL CARIBBEAN WATERS FOR TODAY.

PLEASE REFER TO ZFP AND CWF FOR FORECAST DETAILS.

SJU...
.PR...NONE.
.VI...NONE.

EQUIPMENT...NO PROBLEMS AT THIS TIME.

SEELEY

$$

[cycloneye]

They are focusing more about the amount of rain we can expect here in Puerto Rico than about the waves in the mid and east atlantic as they do great discussions about the atlantic.But once this system goes away from PR they will concentrate on the future of the waves east of us and the models solutions.

[Vortex]

looks like PR are really in for torrential rainfall and maybe isolated severe thuderstorms later tonight...keep us posted