TROPICAL STORM IDA ADVISORY NUMBER  14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
400 PM EST SAT NOV 07 2009

...IDA NEAR HURRICANE STRENGTH...STILL MOVING NORTHWARD...

A HURRICANE WATCH REMAINS IN EFFECT FOR THE YUCATAN PENINSULA OF
MEXICO FROM TULUM TO CABO CATOCHE.  A HURRICANE WATCH MEANS THAT
HURRICANE CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY
WITHIN 36 HOURS.

A TROPICAL STORM WARNING REMAINS IN EFFECT FOR GRAND CAYMAN ISLAND.

A TROPICAL STORM WARNING REMAINS IN EFFECT FOR THE YUCATAN PENINSULA
OF MEXICO FROM PUNTA ALLEN NORTHWARD TO SAN FELIPE.  A TROPICAL
STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED
WITHIN THE WARNING AREA...GENERALLY WITHIN 24 HOURS.

A TROPICAL STORM WARNING IS IN EFFECT FOR THE CUBAN PROVINCE OF
PINAR DEL RIO.  HURRICANE FORCE WINDS COULD SPREAD ACROSS PORTIONS
OF WESTERN CUBA ON SUNDAY AND A HURRICANE WARNING MAY BE REQUIRED
FOR THIS AREA LATER TONIGHT.

A TROPICAL STORM WATCH IS IN EFFECT FOR THE ISLE OF YOUTH.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.

AT 400 PM EST...2100 UTC...THE CENTER OF TROPICAL STORM IDA WAS
LOCATED NEAR LATITUDE 18.9 NORTH...LONGITUDE 84.3 WEST OR ABOUT 200
MILES...325 KM...EAST-SOUTHEAST OF COZUMEL MEXICO AND ABOUT 195
MILES...320 KM...SOUTH OF THE WESTERN TIP OF CUBA.

IDA IS MOVING TOWARD THE NORTH NEAR 10 MPH...17 KM/HR. A TURN TOWARD
THE NORTH-NORTHWEST WITH A GRADUAL INCREASE IN FORWARD SPEED IS
EXPECTED DURING THE NEXT DAY OR SO. ON THE FORECAST TRACK...IDA IS
EXPECTED TO MOVE THROUGH THE YUCATAN CHANNEL ON SUNDAY AND INTO THE
SOUTHEASTERN GULF OF MEXICO SUNDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 70 MPH...110 KM/HR...WITH HIGHER
GUSTS.  IDA IS EXPECTED TO BECOME A HURRICANE TONIGHT OR
SUNDAY...BUT WEAKENING IS FORECAST AFTER IT ENTERS THE GULF OF
MEXICO.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 140 MILES...220 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB...29.23 INCHES.

IDA IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF 3 TO 5 INCHES
OVER PORTIONS OF THE YUCATAN PENINSULA AND WESTERN CUBA...WITH
POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 10 INCHES.  RAINFALL AMOUNTS
OF 1 TO 2 INCHES ARE ALSO POSSIBLE ACROSS THE CAYMAN ISLANDS.

...SUMMARY OF 400 PM EST INFORMATION...
LOCATION...18.9N 84.3W
MAXIMUM SUSTAINED WINDS...70 MPH
PRESENT MOVEMENT...NORTH OR 355 DEGREES AT 10 MPH
MINIMUM CENTRAL PRESSURE...990 MB

TROPICAL STORM IDA DISCUSSION NUMBER  14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112009
400 PM EST SAT NOV 07 2009

THE SATELLITE APPEARANCE OF IDA HAS NOT CHANGED SIGNIFICANTLY THIS
AFTERNOON.  THE AIRCRAFT FOUND THE CENTER A LITTLE NORTH OF THE
EARLIER ESTIMATES...WELL EMBEDDED WITHIN THE CENTRAL DENSE
OVERCAST.  THE PLANE MEASURED A PEAK 850 MB FLIGHT-LEVEL WIND OF 68
KT AND A SFMR SURFACE WIND OF 60 KT. THESE DATA SUPPORT AN INITIAL
INTENSITY OF 60 KT.  CIRRUS ELEMENTS ARE MOVING NORTHEASTWARD...
SUGGESTING MODERATE SOUTHWESTERLY UPPER-LEVEL FLOW OVER THE
CYCLONE.  HOWEVER IT DOES NOT APPEAR THAT SHEAR WILL BE STRONG
ENOUGH IN THE SHORT-TERM TO INHIBIT SOME ADDITIONAL
INTENSIFICATION.  IDA WILL BE TRAVERSING THE VERY WARM WATER OF THE
NORTHWESTERN CARIBBEAN SEA AND THE INTENSITY GUIDANCE NOW
UNANIMOUSLY PREDICTS IDA TO BECOME A HURRICANE WITHIN 12
HOURS...AND THE OFFICIAL FORECAST FOLLOWS SUIT.  AFTER IDA REACHES
THE GULF OF MEXICO...THE SHEAR IS FORECAST TO INCREASE AND WATERS
BEGIN TO COOL. THESE FACTORS SHOULD CONTRIBUTE TO MORE STEADY
WEAKENING.

IDA HAS BEEN MOVING NORTHWARD AT A SLIGHTLY FASTER FORWARD SPEED
TODAY.  THE TRACK GUIDANCE IS TIGHTLY CLUSTERED ON A NORTH-
NORTHWESTWARD MOTION DURING THE NEXT 24 TO 36 HOURS.  THE OFFICIAL
FORECAST DURING THIS PERIOD REMAINS NEAR THE MODEL CONSENSUS BUT HAS
BEEN ADJUSTED A LITTLE EASTWARD PRIMARILY DUE TO THE MORE NORTHWARD
INITIAL POSITION AND HEADING.  THEREAFTER...THERE REMAINS
SIGNIFICANT DIFFERENCES IN THE GUIDANCE AS TO HOW IDA INTERACTS
WITH A MID- TO UPPER-LEVEL TROUGH THAT MOVES INTO THE NORTHWESTERN
GULF OF MEXICO IN A COUPLE OF DAYS.  THE 12Z GFS...ECMWF...AND HWRF
CONTINUE TO SHOW THE CYCLONE REACHING THE NORTHERN GULF COAST IN
ABOUT 72 HOURS AS IT BECOMES AN EXTRATROPICAL CYCLONE.  THE
OFFICIAL FORECAST IS A LITTLE FASTER THAN THE PREVIOUS ONE...AND
HAS ONCE AGAIN BEEN SHIFTED NORTHWARD.  THE NEW TRACK NOW SHOWS A
POSITION JUST SOUTH OF THE NORTHERN GULF COAST IN 3 DAYS.
THEREAFTER...MOST OF THE GUIDANCE TURNS THE CYCLONE EASTWARD...AND
SO DOES THE OFFICIAL FORECAST.  BY 120 HOURS...SOME OF THE GUIDANCE
SUGGEST THAT THE LOW WILL BE ABSORBED BY A FRONTAL BOUNDARY...AND
THE OFFICIAL FORECAST DOES NOT PROVIDE A 5-DAY POSITION FOR THIS
REASON.

MOST OF THE GLOBAL MODELS SHOW A LARGE PRESSURE GRADIENT BETWEEN
A HIGH PRESSURE RIDGE OVER THE SOUTHEASTERN UNITED STATES AND THE
TROPICAL CYCLONE.  THIS IS ALREADY CONTRIBUTING TO A LARGE AREA OF
STRONG WINDS OVER THE SOUTHERN GULF OF MEXICO WHICH IS NOT DIRECTLY
ATTRIBUTABLE TO IDA.