Hurricane Earl Set For Brush With US Coast From Hatteras to Cape Cod September 2, 2010

Hurricane Earl IR Rainbow Image 1915Z 09.02.10 Click for real time loop

Hurricane Earl Spaghetti Model 18Z 09.02.10

If you recall a few days ago I had talked about the challenges for Hurricane Earl maintaining its ferocity.  One of the main concerns that I had was a huge amount of dry air that Earl was getting ready to move in to.    I was a bit surprised that the NHC didn’t mention it more often and it appeared that Earl was able to fend off the dry air.  However, it seems apparent now that dry air did indeed work its way into the storm and Earl rapidly decreased in intensity on Thursday evening.   The dry air intrusion seems to have coincided with what so often seems to be the case which is that Hurricane Earl began an eyewall replacement cycle during the late morning on Thursday, prior to a potential Outer Banks of North Carolina landfall.   Most likely, Earl yesterday reached its maxima when it topped out at 145 mph with gusts to 165 and a central pressure somewhere in the neighborhood of 930 mb.  If you look at the satellite loop, you will note that the eye seems to fill in.  That was not an indication that the storm is dying, but instead was indicative of a very healthy hurricane.  What typically happens with an eyewall replacement cycle is that the maximum winds near the eye decrease somewhat, but the overall energy gets dispersed throughout the storm.  Hence, a broader field of strong winds results.  At 3:30 PM EDT Earl essentially had two eyes.  The old eye was collapsing and a new, much larger,  eyewall was developing around it.  So, winds decreased and the pressure rose to 943 mb but its a much larger storm.  By 5 pm Earl’s maximum winds had dropped to 115 mph and the pressure was up to 947 mb.   We saw that with Hurricane Katrina.  As it made landfall, the winds dropped off to 125 mph in far western Mississippi and near the mouth of the Mississippi River yet, all the way east over to Mobile, AL winds were in excess of 100 mph.  So, regardless of exactly where the eye of the storm runs in relation to North Carolina, the winds on the Outer Banks and even for some distance inland will be hazardous.

Hurricane Earl Spaghetti Model Intensity Forecast 18Z 09.02.10

On Thursday afternoon, another potential problem was that, if the replacement cycle was complete before it got to North Carolina, then it could have been in a re-intensification stage and perhaps deepening back toward a category 4 hurricane.   At this point, that is not only unlikely but also rather irrelevant.  As of 3:30 pm EDT on Thursday, Earl was moving at about 355 degrees, or just slightly west of due North.  It had crossed just west of 75 degrees West Longitude.  Cape Hatteras is at 75 degrees 15 minutes W. Long and 35 degrees 30 minutes North Latitude.  I believe that there is a fair chance that Cape Hatteras will take a direct hit though if Earl is just off shore, then it could be in the western eyewall.  If you look closely at the 2PM forecast discussion, the NHC forecast position at 2AM is 75 degrees West Long and 33.5 degrees North Lat, or right over Cape Hatteras.  At two AM on Saturday, the storm is forecast to have maximum winds of nearly 100 mph and is located at 40.o N and 75.8 W or almost exactly over Marthas Vineyard.   Keep in mind a wobble to the right by 25 miles would spare the eye passing over these locations but it would still be close enough to be potentially destructive.  By 8PM EDT Earl’s maximum winds had decreased to 110 mph and the liklihood of the trend of winding down is rapidly diminishing.  It would appear from the satellite depiction that upper shear is starting to work on Earl as well as dry air from the Eastern United States.

N. Atlantic IR 1945Z 09.02.10 Click For real time loop

Hurricane Earl NHC Forecast Track 2PM 09.02.10

Once it passes Cape Hatteras, three things will start to work in conjunction to turn it North Northeast and then Northeast.  First, there is the Coriolis Force, which is the force that wants to turn a cyclone to the right of its path in the Northern Hemisphere.  That force increases as the storm moves poleward.  Then there are the mid lattitude prevaling westerlys.  That is the general persistent wind flow in the mid lattitudes of the Northern Hemisphere.  Finally, there is a frontal boundary that is progressing Eastward.  As of 3:30 PM EDT it was just west of the Ohio Valley.  That is some distance from the coast and not moving as fast as we might like.  But, as it approaches, winds ahead of the front or trof will increase from the Southwest.  That will increase Earl’s forward speeed and also serve to knock up the upper air support of the hurricane.   As mentioned earlier, by 8PM EDT the satellite imagery appears to indicate that the southwesterly shear was already taking a toll on Earl.

Structure of a hurricane

Essentially, a hurricane is a warm-core area of low pressure that is a giant heat engine, drawing its energy from warm ocean water.  The ocean has to be at least 80 F.  Not every surface low over the ocean becomes a hurricane though.  It is essential that a hurricane get what I call a “hat” or an anticyclone aloft.  That would be a big area of high pressure.  That is why when you look at a satellite loop, you see clouds going clockwise, yet at the surface, the hurricane winds go counter clockwise.  The upper level high serves to vent the storm.  The structure of a hurricane is such that, at the surface, the flow is toward the center in a counter clockwise fashion.  When the air reaches the center it has nowhere to go but up.  Aloft, the high pressure features air that sinks and goes outward in a clock wise fashion.  The high aloft helps push out the rising air below and as it does, it allows for a more even flow of air rising from below.  When these winds from the southwest kick in, it will disrupt the ventiing flow aloft which will limit the rising air below.  All of that should start to occur in earnest once Earl gets past the Outer Banks.  At that same time, it will start to cross over water that is either near or below 80 F and eventually will get over water that is definitely too cold to support a tropical system.

Atlantic Sea Surface Temperatures-Click for Loop

So, look for rapid weakening of the storm beginning off the North Carolina coast and thereafter.  It will also lose its tropical characteristics probably before it gets to Cape Cod.  Nevertheless, winds of at least hurricane force will continue as the storm moves north.  The forecast track takes it very close to Long Island and even over Cape Cod.  While it may lose its hurricane classification, it will also provide a very healthy storm surge and a high tide will only aggravate the situation.  Click here to find the storm surge forecast for your location.  The storm will also be moving very very quickly so, on the one hand, the effects will not last as long but the conditions will also deteriorate very rapidly.  No one can tell with exact certitude where the center of Earl will travel.  That should not surprise anyone when one considers that the earth is 25,000 miles around;  a margin of error of say 50 miles represents just a fraction of a percent but, it can be the difference between terrible conditions and horrific conditions.  Most of the time, people who try to ride out a storm vow they will never do so again.  Sometimes, they lose their lives and by that time it is obvious they made a mistake.  With hurricanes you do not get a second chance.  Getting out of the way is the better part of valor.  Also, Earl’s interaction with the front may enhance rain fall inland greatly.  Flooding will be a concern from not only the surge, but also rainfall.

N. Atlantic Basin Total Precipitable Water Image-Click For Loop That Clearly Indentifies Cyclone in the N. Atlantic

Gaston NHC Forecast Track 2PM 09.02.10

Gaston Spaghetti Model 18Z 09.02.10

Behind Earl is Fiona which should not be an issue for the United States and perhaps no one.  What is of greater concern is Tropical Storm Gaston.  It is much farther south than Danielle was, or Earl or Fiona.  Fiona will get picked up by the same trof that is picking up Earl and Danielle also got picked up by a trof.  But, Gaston is so far south that it will most likely sneak under any trof and westerly flow around  an Atlantic high should drive Gaston in a westerly fashion.  Most models put Gaston either near or South of the Dominican Republic in about a week and most develop it into a hurricane.  It will not be traveling over any water that has been worked over by Danielle, Earl or Fiona so it should be plenty warm enough and conditions should be conducive for development, perhaps even enough to support a major hurricane.  Its location will offer scenarios for it to enter the Gulf of Mexico as well as potentially affecting the East Coast. 

HURRICANE EARL DISCUSSION NUMBER  34
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM EDT THU SEP 02 2010

DATA FROM A RECONNAISSANCE PLANE INDICATE THAT EARL HAS WEAKENED A
LITTLE BIT THIS AFTERNOON.  THE CENTRAL PRESSURE ROSE TO 947
MB…AND A BLEND OF THE SFMR MEASUREMENTS AND FLIGHT-LEVEL WINDS
SUGGEST THAT THE INITIAL INTENSITY HAS DECREASED TO 100 KNOTS. EARL
SHOULD CONTINUE TO WEAKEN GRADUALLY AS THE SHEAR INCREASES AND THE
HURRICANE SHOULD WEAKEN EVEN FASTER AFTER 24 HOURS AS IT MOVES OVER
A COLDER OCEAN.  AFTER CROSSING CANADA IN 48 HOURS…EARL SHOULD
BECOME POST-TROPICAL/EXTRATROPICAL AND THEN DISSIPATE AS IT IS
ABSORBED BY A MUCH LARGER EXTRATROPICAL CYCLONE.

SATELLITE AND RECONNAISSANCE FIXES SHOW…AS ANTICIPATED…THAT EARL
HAS TURNED NORTHWARD AND IS MOVING 360 DEGREES AT 16 KNOTS. THE
STEERING PATTERN CONTROLLING THE MOTION OF EARL…AND THE
CONSISTENCY IN TRACK GUIDANCE…HAVE BEEN ADEQUATELY DESCRIBED IN
PREVIOUS DISCUSSIONS. EARL IS ABOUT TO BECOME EMBEDDED IN THE
MID-LATITUDE FLOW AND IT IS READY TO GRADUALLY TURN TO THE
NORTH-NORTHEAST AND NORTHEAST WITH AN INCREASE IN FORWARD SPEED.

ALTHOUGH THE MAXIMUM WINDS IN THE CORE HAVE DECREASED…EARL
CONTINUES TO BE A LARGE AND POWERFUL HURRICANE.

FORECAST POSITIONS AND MAX WINDS

INITIAL      02/2100Z 32.5N  75.2W   100 KT
12HR VT     03/0600Z 34.8N  74.8W    95 KT
24HR VT     03/1800Z 38.0N  72.7W    85 KT
36HR VT     04/0600Z 41.7N  69.0W    75 KT
48HR VT     04/1800Z 46.5N  64.5W    50 KT…POST-TROP/EXTRATROP
72HR VT     05/1800Z…DISSIPATED

$$
FORECASTER AVILA

Hurricane Earl Eyes US: Hurricane Warning Flags Flying on East Coast September 1, 2010

Hurricane Earl 1915Z IR Rainbow Image 09.01.10-Click Image for Real time Loop

Click Here For The Most Recent Update Regarding Hurricane Earl’s Brush with the US East Coast

Hurricane Earl 1915Z Visible Satellite Image 09.01.10-Click Image for Real Time Loop

If you recall, yesterday I mentioned that one aspect of the forecast regarding Hurricane Earl was the dry air in which Earl was moving into.  I had thought that perhaps dry air might work its way into the circulation of the hurricane and perhaps limit its intensity potential or even bring it down a notch or two.  At 5 AM on Wednesday September 1, 2010 the National Hurricane Center included this bit of information near the end of it’s discussion: ” …WATER VAPOR IMAGERY SHOWS A TONGUE OF MID/UPPER-LEVEL DRY AIR WRAPPED MORE THAN HALFWAY AROUND THE CYCLONE.”  I honestly had been surprised that they had not mentioned that potential earlier because the the scale of the dry air ahead of the storm was rather large.   Nevertheless, by Wednesday afternoon, the outflow symmetry of Earl looks to have improved  and the dry air looks to have been absorbed without a whole lot of disruption; perhaps it hurt Earl a bit.  But, Earl overcame the dry air and at 5pm EDT on Wed Sept 1 had maximum winds of 135 mph with gusts to 160 mph.  Central pressure was 941mb and was moving at 310 -320 degrees (NW) at 17 mph.    The dry air was one of the “challenges” that I referred to that I felt Earl would face in maintaining its intensity.  There are other issues at play as well that suggest the storm has seen its better days and its ferocity will not be as great as it once was, or even feared it would be, when it affects the US Coast.  Nevertheless, I would not take the storm lightly and it would be advisable to get out of its way if you may be in the path of Earl.

N. Atlantic Basin Total Precipitable Water Image-Click For Loop That Clearly Indentifies Cyclone in the N. Atlantic

18Z Hurricane Earl Spaghetti Model Track 09.01.10-Note Model track or two suggest a mainland landfall

As of 5 PM EDT Wednesday, Hurricane Warning flags have been hoisted from  Bouge Inlet, North Carolina to the North Carolina/Virginia.  A Hurricane Watch extends from the North Carolina/Virginia border to Cape Henlopen, DE and from Woods Hole, MA to Sagamore Beach, MA.  Tropical Storm Warnings are posted from the North Carolina/Virginia border to Sandy Hook, NJ.  A Tropical Storm Warning means tropical storm conditions are likely within 36 hours, A Hurricane Watch and a Tropical Storm Watch means that those conditions are possible within 48 hours.  A Hurricane Warning means that hurricane conditions are expected in the warned area with the onset of tropical storm force winds expected within 36 hours.  Tropical Storm winds are considered to be 40 to 73 mph and winds are considered hurricane force at 74 mph.  Remember, these are sustained winds, not gusts.  Winds can gust to at least 20% higher than the sustained winds.  It is not uncommon with a hurricane for a region to experience continuous hurricane force winds for many hours.  Most people who survive “riding out” a hurricane swear they will never do so again.  Wind is only part of the story as torrential rain is always a part of a hurricane and the storm surge associated with any hurricane is typically the gravest life taker.  People generally have no idea just how powerful the sea can be.  Click here for to find the storm surge probability forecast for your region.

Note the Trof in N. Central US on 1845Z Atlantic IR Rainbow Image 09.01.10-Click Image for Real Time Loop

18Z Hurricane Earl Spaghetti Model Intensity Graph 09.01.10

By midday on Wednesday,  Hurricane Earl had continued its gradual curvature around a big fat ridge extending from the Atlantic.  As the ridge continues to move eastward,  Earl will continue its right hand shifting and will eventually be moving due North.  By late Thursday, the long anticipated trof moving across the northern United States will be close enough to pick up Earl.  The result will be an increase in forward speed as well as a turning of the storm; first North-Northeast and eventually Northeast.  The timing of the trof will be the determining factor as to the precise track of Earl up the East Coast, particularly off of New England.  The variable is so slight that no one can say with certainty how it will play out.  An hour or so timing difference of the trof’s influence on Earl can make the difference between the storm staying offshore or running over land.  Suffice it to say, it will be at least a close call and no one along the NE Coast of the United States will escape some affect of Hurricane Earl. 

Atlantic Sea Surface Temperatures-Click for Loop

While the shearing winds from the Southwest ahead of the trof and the dry air trying to work its way into Earl may serve to limit its intensity,  forecasts continue to call for a major hurricane with winds of 100 to 120 mph running just off the North Carolina, Virginia, Maryland and Delaware coasts.  By the time its off the New England coast, it will be probably scooting along at least at 30 mph and winds will have diminished from weakening due to the shearing winds that mess up its upper support as well as colder water. Tropical Cyclones need surface water temperatures of at least 80 F current coastal conditions from off of Delware northward fall below that level.  Farther out though, in the Gulf Stream, waters remain above 80 F extend a shade farther north.   However, hurricane conditions may still be probable for Long Island and Cape Cod, if not the mainland of the New England states.  The official track keeps the storm offshore but it would not take much of a deviation, say 20 miles, for the eye of the hurricane to run right over Long Island and perhaps Cape Cod or Nantuckett Island.  While its not entirely likely, it is not totally out of the question for Earl to actually make at least a partial landfall on some portion of the mainland. 

NHC Hurricane Earl Forecast Track 5PM EDT 09.01.10

While the winds may back off as it heads farther North, the increase in forward speed may serve to enhance the storm surge to the right of the storm.  Further, given that Earl was a big bopper, the sea will not necessarily react as quickly to diminishing winds so the surge may be on the top end of the normally expected storm surge associated with a minimal hurricane running up the East coast.  So, when you hear the forecasts call for a category 1 hurricane off the Jersey shore of off of the New England coast, it would be advisable not to pooh-pooh it as the destructive potential of a  category 1 hurricane can be somewhat excessive. 

18Z Tropical Depression 9 Spaghetti Model Track 09.01.10

Behind this is Tropical Storm Fiona which has been experiencing some difficulty as the outflow from Earl has been disrupting its outflow.  Aside from its intensity, the same trof that is picking up Earl will most likely pick up Fiona as well, regardless of its strength, and should turn it north well before it threatens the US coast.  Behind Fiona is a Tropical Wave (Invest 98) and Tropical Depression 9 which was designated at Tropical Storm Gaston at 5pm EDT September 1.  Invest 98 appears to be running over the same worked-over water as Danielle, Earl and Fiona and may have a difficult time developing.  However, Tropical Storm Gaston is farther south and the initial modeling data suggests its track will be more westerly and as it will be far enough south as to not be influenced by any trofs farther North.  While there is no data currently showing a rapid intensification, a few models do indicate that it will develop into a hurricane and the general track would suggest the potential exists for it to some day affect the US coast from the Gulf of Mexico to the East Coast.  It’s a long way out and there are many scenarios so there will be time to monitor its development. 

HURRICANE EARL DISCUSSION NUMBER  30
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
500 PM EDT WED SEP 01 2010

VISIBLE SATELLITE IMAGES INDICATE THAT THE EYE HAS BECOME VERY
DISTINCT…WITH OJECTIVE T-NUMBERS OSCILLATING AROUND 6.0 FOR THE
PAST FEW HOURS. AN AIR FORCE PLANE MEASURED FLIGHT-LEVEL WINDS OF
138 KNOTS AND A MINIMUM PRESSURE OF 941 MB IN THE LAST FIX.
HOWEVER…SFMR MEASUREMENTS WERE A LITTLE LOWER. A COMPROMISE OF
THESE DATA SUPPORTS AN INITIAL INTENSITY OF 115 KNOTS.
HOWEVER…EARL COULD FLUCTUATE IN INTENSITY DURING THE NEXT 12 TO
24 HOURS BUT SHOULD BEGIN TO GRADUALLY WEAKEN AS IT REACHES
COOLER WATERS AND MOVES INTO HIGHER SHEAR BEYOND 36 HOURS. BY DAY 5
THE HURRICANE SHOULD HAVE BEEN ABSORBED BY A LARGE EXTRATROPICAL
CYCLONE WELL NORTH OF CANADA.

SATELLITE AND RECONNAISSANCE AIRCRAFT FIXES INDICATE THAT EARL
HAS BEEN MOVING RELENTLESSLY TOWARD THE NORTHWEST OR 310 DEGREES
AT 15 KNOTS. THE HURRICANE IS ABOUT TO REACH THE WESTERN EDGE OF
THE SUBTROPICAL RIDGE AND SHOULD BEGIN TO TURN MORE TO THE
NORTH-NORTHWEST AND NORTH LATER TONIGHT AND THURSDAY. IN ABOUT 36
HOURS OR SO…THE HURRICANE WILL ENCOUNTER THE BASE OF THE
MID-LATITUDE WESTERLIES AND SHOULD BEGIN TO RECURVE OR TURN TO THE
NORTHEAST WITH AN INCREASING FORWARD SPEED. THIS IS THE SOLUTION
CONSISTENTLY PROVIDED BY TRACK MODELS…WHICH HAVE EARL PASSING TO
THE EAST BUT NOT FAR FROM THE OUTER BANKS OF NORTH CAROLINA ON
THURSDAY NIGHT. ONLY A SMALL WESTWARD DEVIATION OF THE TRACK TO THE
WEST WOULD BRING THE CORE OF THE HURRICANE TO THE COAST.

GIVEN THE FORECAST TRACK…THE LARGE SIZE OF THE WIND FIELD…AND
THE EXPECTED INCREASE IN FORWARD SPEED WATCHES AND WATCHES HAVE
BEEN EXTENDED NORTHWARD ALONG THE EAST COAST OF THE UNITED STATES.

FORECAST POSITIONS AND MAX WINDS

INITIAL      01/2100Z 26.3N  73.3W   115 KT
12HR VT     02/0600Z 28.4N  74.7W   115 KT
24HR VT     02/1800Z 31.7N  75.4W   110 KT
36HR VT     03/0600Z 35.1N  74.7W   100 KT
48HR VT     03/1800Z 38.5N  72.2W    90 KT
72HR VT     04/1800Z 46.5N  63.5W    60 KT
96HR VT     05/1800Z 58.0N  57.0W    40 KT…POST-TROP/EXTRATROP
120HR VT     06/1800Z…DISSIPATED

$$
FORECASTER AVILA

Hurricane Gustav Making Landfall and Slowing Down; Two More Storms September 1, 2008

for a more recent update on Hurricane Gustav, Hurricane Hanna and Tropical Storm Ike, CLICK HERE

For a Radar Loop to track Hurricane Gustav, CLICK HERE. You can navigate anywhere in the country to street level. The image can be looped with clouds and lightning added.

Hurricane Gustav NHC forecast Track 11AM 0901

Hurricane Gustav made landfall about 70 miles SW of New Orleans and 100 miles SE of Lafayette. Pretty close to Houma. The structure got fairly decent and the

Hurricane Gustav Spaghetti Model 0901 12Z

pressure was at a level that could have supported higher winds, but the satellite photo indicates to me that the dry air that the hurricane hunter reported last night has worked into the center. So, while the pressure was still at 955 mb, the winds fell just prior to landfall to 110 mph and is moving NW at 15 mph. If you want to play the category game, it was a Cat 2 at landfall….if it had stayed 5 mph stronger, it would have been a Cat 3. I sometimes think this “what category is it?” stuff is silly. Anyway, it still remains to be seen how the water piling up into Lake Borgne will affect the Intercoastal Waterway and Industrial Canal. However, cautiously it would appear the distance from New Orleans and the lesser strength was sufficient to keep the storm surge rather manageable in New Orleans. But, they thought that about Katrina too. The reporters were in the French Quarter saying that “we dodged a bullet” when the east side of town had been under water for 6 hours. I suspect that the levees will be under pressure and perhaps even topped to some degree but probably not to the degree of Katrina. On Sunday evening, it was interesting that while the central winds were not that great, the hurricane force winds were somewhat broad and that seems to be holding true with winds in MIssissippi running close to hurricane force. There may be a lot of tornados with this one, but one cannot really tell for certain.

Gustav Rain Forecast 120 hours

The boys at the National Hurricane Center have done a great job as the track went almost exactly as forecast for several days. Despite the variables, the track is pretty much running up the eastern side of Vermilion Bay toward Fort Polk. It is still anticipated to slow to a crawl in west Louisiana. Rainfall will be excessive. The main difference between this and Fay is that the upper support is anticipated to be chopped off in the next few days. That probably won’t limit the rainfall, but should limit the winds a bit and also prevent the storm from being as long lived as Fay.

Tropical Storm Hanna Forecast Track 11AM 0901

Tropical Storm Hanna is getting better organized. It is expected to approach

Tropical Depression 9 Forecast Track 0901 11AM

minimal hurricane status and loop through the Bahamas, along the east coast of Florida and into Georgia or South Carolina and then up the east coast. However, the most recent path of toward the SW is rather interesting and is not part of the plan and looks similar to the track from a few days ago when the data supported a run down and around into the Gulf. Stay tuned. A tropical Depression has also formed and and is expected to increase in intensity. There are also other areas of interest in the Atlantic. Here is the National Hurricane Center Gustav Discussion for 11AM Monday:

HURRICANE GUSTAV DISCUSSION NUMBER  32
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072008
1100 AM EDT MON SEP 01 2008

THE CENTER OF GUSTAV MADE LANDFALL ALONG THE LOUISIANA COAST NEAR
COCODRIE ABOUT 1430 UTC.  DURING THE PAST FEW HOURS...THE EYE
BECAME BETTER DEFINED ON RADAR.  HOWEVER...WIND DATA FROM AIR FORCE
RESERVE AND NOAA AIRCRAFT ALONG WITH DOPPLER RADAR WINDS SUGGESTS
THAT GUSTAV WEAKENED TO A CATEGORY TWO HURRICANE BEFORE LANDFALL.
THE INITIAL INTENSITY OF 95 KT IS BASED ON THE AIRCRAFT DATA...AND
THIS MIGHT BE A LITTLE GENEROUS.

THE INITIAL MOTION IS 310/13.  GUSTAV IS BEING STEERED NORTHWESTWARD
BY A MID-LEVEL RIDGE OVER THE EASTERN UNITED STATES.  THE CYCLONE
IS EXPECTED TO CONTINUE NORTHWESTWARD WITH A DECREASE IN FORWARD
SPEED AS A LOW-LEVEL RIDGE BUILDS TO THE THE NORTH AND NORTHWEST.
THE FORECAST TRACK IS ESSENTIALLY AN UPDATE OF THE PREVIOUS
FORECAST THROUGH 48 HR.  AFTER THAT TIME...THE GUIDANCE IS NOW IN
BETTER AGREEMENT ON A SLOW NORTHWARD MOTION...SO THE 72-120 HR PART
OF THE TRACK IS CHANGED FROM A WESTWARD DRIFT TO A NORTHWARD DRIFT.

GUSTAV SHOULD WEAKEN AS IT MOVES INLAND...ALTHOUGH THE WEAKENING
WILL LIKELY BE SLOW AT FIRST AS THE CENTER CROSSES THE SOUTH
LOUISIANA MARSHES.  A FASTER WEAKENING IS EXPECTED IN 6-12 HR AS
THE CENTER REACHES MORE SOLID GROUND.  AFTER 48 HR...GUSTAV IS
LIKELY TO SHEAR APART...WITH THE UPPER-LEVEL PORTION OF THE CYCLONE
MOVING NORTHEASTWARD AND LEAVING THE SURFACE CENTER BEHIND.
THUS...THE FORECAST SHOWS THE SYSTEM BECOMING A REMNANT LOW BY 72
HR.

THE THREAT OF HIGH STORM SURGE WILL CONTINUE ALONG THE LOUISIANA
COAST FOR SEVERAL MORE HOURS...AND THE THREAT OF HEAVY RAINS WILL
CONTINUE FOR SEVERAL DAYS.

FORECAST POSITIONS AND MAX WINDS

INITIAL      01/1500Z 29.2N  90.8W    95 KT
 12HR VT     02/0000Z 30.3N  92.4W    70 KT...INLAND
 24HR VT     02/1200Z 31.3N  93.8W    40 KT...INLAND
 36HR VT     03/0000Z 31.9N  94.6W    30 KT...INLAND
 48HR VT     03/1200Z 32.4N  95.3W    25 KT...INLAND
 72HR VT     04/1200Z 33.0N  95.5W    20 KT...INLAND REMNANT LOW
 96HR VT     05/1200Z 33.5N  95.5W    20 KT...INLAND REMNANT LOW
120HR VT     06/1200Z 34.0N  95.5W    20 KT...INLAND REMNANT LOW

$$
FORECASTER BEVEN