mrpuertorico's WunderBlog

Last Updated: 11:00 AM GMT on September 01, 2009 — Last Comment: 3:36 PM GMT on August 15, 2009

	STORM CONDITIONS POSSIBLE THU AND THU NIGHT

Posted by: mrpuertorico, 7:43 PM GMT on July 13, 2006

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
420 AM AST TUE SEP 1 2009

.SYNOPSIS...MID-UPPER LEVEL RIDGING WILL BUILD INTO THE REGION
TODAY AND MAINTAIN A SUBSIDENT PATTERN ACROSS THE REGION THROUGH
TOMORROW. BROAD AREA LOW PRES TO THE EAST OF THE LEEWARD ISLANDS
STILL NOT WELL ORGANIZED BUT COULD BECOME THE FIFTH NAMED STORM OF
THE 2009 HURRICANE SEASON AND MAY IMPACT THE ISLANDS OF THE NORTHEAST
CARIBBEAN TOWARD THE END OF THE WORK WEEK. INTERESTS IN PR/USVI
SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

&&

.DISCUSSION...FCST FOR TODAY IS QUITE SIMPLE. LARGE SCALE
SUBSIDENCE WILL ENCOMPASS THE REGION TODAY THROUGH TOMORROW AS
HEIGHTS RISE IN RESPONSE TO BUILDING MID-UPPER LVL RIDGE. THIS
WILL SIGNIFICANTLY LIMIT SHOWER ACTIVITY OVR THE NEXT 48 HRS. SHOWERS
IF ANY WILL BE CONFINED TO THE SOUTHWEST CORNER OF PR DUE TO
NORTHEAST WINDS.

FCST FOR THU-FRI WILL BE HIGHLY DEPENDENT ON THE TRACK/EVOLUTION
OF BROAD AREA OF LOW PRES LOCATED ABOUT 350 MILES EAST OF THE
LEEWARD ISLANDS WHICH AT THIS TIME REMAINS HIGHLY UNCERTAIN.
CENTER FIXES DONE AT 06Z BY TAFB AND SAB AGENCIES WERE
AT 16.3N 55.6W AND 16.4N 55.9W RESPECTIVELY. COORDINATED WITH
BOTH ANALYSTS ON THE PHONE THIS MORNING AND BOTH INDICATED A LOW
CONFIDENCE IN THEIR RESPECTIVE FIXES WITH THE POSSIBILITY OF
MULTIPLE CENTERS. A 0406Z TMI MICROWAVE PASS SUGGESTS THE LOW
LEVEL CENTER IS ON THE WESTERN EDGE OF THE CONVECTION BUT WITH NO
CLOSED CIRCULATION YET. 06Z EARLY CYCLE NHC MODELS SHOW TRACKS
RANGING FROM ALONG THE SOUTH COAST OF PR TO AS FAR NORTH AS 20N
IN THE 72 TO 96 HR TIME FRAME OR THU NIGHT THROUGH FRI NIGHT BUT
DO NOT EXPECT MODELS TO GET A GOOD HANDLE ON THE TRACK FCST UNTIL
AT LEAST ANOTHER 24 TO 36 HRS. INTERESTS IN PR/USVI ARE REMINDED
THAT TRACK FORECAST ERRORS CAN BE IN THE ORDER OF 167 TO 230
NAUTICAL MILES IN THE 72 TO 96 HR TIME FRAME. THE FIRST HURRICANE
HUNTER PLANE IS SCHEDULED TO INTERCEPT THE DISTURBANCE THIS
AFTERNOON AT 2PM AND WILL GIVE A BETTER PICTURE OF THE STRUCTURE
OF THE STORM...ITS EXACT LOCATION AND WIND FIELD.

AS MENTIONED IN THE TROPICAL DISCUSSION FROM HPC`S INTERNATIONAL
DESK YESTERDAY...THE FLOW DOMINATING THE ATLC TO THE NORTH OF 20N
AND TO THE EAST OF 70W IS CHARACTERIZED BY NUMEROUS TUTT LOWS WITH
CELLS OF THE SUBTROPICAL RIDGE BEING MIGRATORY AND OF SHORT
DURATION RESULTING IN VERY ILL DEFINED STEERING CURRENTS. I WOULD
EXPECT THE TRACK FCST WITH THIS STORM TO BE EXTREMELY CHALLENGING
WITH LOTS OF ERRATIC MOVEMENTS AND WOBBLES WITH A MUCH HIGHER THAN
AVERAGE UNCERTAINTY.

THE BIGGEST THREAT FROM THE STORM IS THE POTENTIAL TO PRODUCE A
TON OF RAINFALL ALONG AND NEAR THE TRACK OF THE STORM WHICH IS
STILL HIGHLY UNCERTAIN AS MODELS SUGGEST SYSTEM MOVING AT AVERAGE
OF SPEED OF ABOUT 7 KTS AS IT MOVES ACROSS THE REGIONAL WATERS
WITH THE GFDL INDICATING SPEEDS AS SLOW AS 4 KT AT TIMES. THE MOST
LIKELY TIME FRAME FOR POTENTIAL IMPACTS LOOKS TO BE BETWEEN THU
NIGHT AND FRI NIGHT. SINCE THIS IS STILL BEYOND 48 HRS IT IS TOO
EARLY TO ISSUE ANY FLASH FLOOD WATCHES AT THIS TIME.

HURRICANE STATEMENT WILL BE FRESHEN LATER THIS MORNING TO UPDATE
STORM POSITION AND POTENTIAL IMPACTS.

&&

.AVIATION...VFR NEXT 48 HRS. TROPICAL STORM OR GALE CONDITIONS ARE
POSSIBLE THU NIGHT-FRI NIGHT.

&&

.MARINE...GOOD BOATING CONDITIONS EXPECTED THROUGH TOMORROW XCPT
AMZ710 WHERE SCA IS NOW IN EFFECT BEGINNING TONIGHT AFTER
MIDNIGHT. MARINE CONDITIONS WILL BEGIN TO DETERIORATE ON THU.
TROPICAL STORM OR GALE CONDITIONS ARE POSSIBLE THU NIGHT-FRI NIGHT.
6 TO 8 FEET SEAS LIKELY ATLC WATERS AND ANEGADA PASSAGE BUT ARE
SUBJECT TO CHANGE IF STORM DEVELOPS FURTHER.

--------------------PR SWINE FLU UPDATE---------------------
Death toll rises to 30 confirmed deaths/ 302 confirmed cases/ 2,093 probable cases island wide