Tropical Weather Discussion 2011

[venture]

TD7 was upgraded to TS Gert earlier today.

TROPICAL STORM GERT DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072011
1100 PM AST SUN AUG 14 2011

ON SATELLITE IMAGERY...GERT IS CHARACTERIZED BY A FAIRLY CIRCULAR
AREA OF DEEP CONVECTION BUT IS LACKING IN BANDING FEATURES. A
SMALL UPPER-LEVEL ANTICYCLONE THAT FORMED OVER THE STORM IS
PROVIDING SOME MODEST OUTFLOW...PARTICULARLY OVER THE SOUTHERN
SEMICIRCLE OF THE CIRCULATION. BASED ON THE AIRCRAFT OBSERVATIONS
FROM A FEW HOURS AGO...THE MAXIMUM WINDS ARE ESTIMATED TO BE 40
KT...WHICH IS A LITTLE ABOVE THE LATEST DVORAK INTENSITY ESTIMATES.
GERT IS LIKELY TO REMAIN OVER WARM WATERS AND IN A WEAK SHEAR
ENVIRONMENT FOR ANOTHER DAY OR SO...WHICH SHOULD ALLOW FOR SOME
INTENSIFICATION. BY AROUND 48 HOURS...GLOBAL MODELS INDICATE AN
ABRUPT INCREASE IN VERTICAL SHEAR AS GERT APPROACHES A BELT OF
STRONG UPPER-LEVEL WESTERLIES. THE OFFICIAL INTENSITY FORECAST IS
SLIGHTLY BELOW THE MODEL CONSENSUS. IN 72 HOURS...PERHAPS
SOONER...GERT IS LIKELY TO BECOME EMBEDDED IN A FRONTAL ZONE AND
TRANSFORMED INTO AN EXTRATROPICAL CYCLONE. BEYOND THAT TIME...THE
SYSTEM IS EXPECTED TO BECOME ABSORBED BY A LARGE HIGH-LATITUDE LOW
PRESSURE SYSTEM.

LATEST SATELLITE IMAGES INDICATE THAT THE FORWARD SPEED IS
INCREASING AND THE MOTION IS ESTIMATED TO BE AROUND 345/10. GERT
IS MOVING BETWEEN A RATHER DEEP MID-LEVEL TROUGH THAT IS NEARING
THE U.S. EAST COAST AND A SUBTROPICAL HIGH OVER THE CENTRAL
ATLANTIC. THE TRACK MODEL GUIDANCE IS IN GOOD AGREEMENT ON A
GRADUAL TURN TOWARD THE NORTH...THEN NORTH-NORTHEAST AND EVENTUALLY
NORTHEAST WITH INCREASING FORWARD SPEED OVER THE NEXT FEW DAYS.
THE CURRENT OFFICIAL FORECAST IS A LITTLE SLOWER THAN THE LATEST
MULTI-MODEL CONSENSUS AND SLIGHTLY FASTER THAN THE PREVIOUS NHC
FORECAST.

INTERESTS IN BERMUDA ARE REMINDED NOT TO FOCUS ON THE EXACT FORECAST
TRACK OF GERT AS ONLY A SLIGHT DEVIATION TO THE LEFT DURING THE
NEXT 12 HOURS COULD BRING STRONG WINDS CLOSE TO...OR OVER...THE
ISLAND.

FORECAST POSITIONS AND MAX WINDS

INIT 15/0300Z 30.2N 63.3W 40 KT 45 MPH
12H 15/1200Z 31.9N 63.4W 45 KT 50 MPH
24H 16/0000Z 34.7N 62.2W 50 KT 60 MPH
36H 16/1200Z 38.5N 59.5W 55 KT 65 MPH
48H 17/0000Z 42.0N 55.0W 50 KT 60 MPH
72H 18/0000Z 47.0N 40.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
96H 19/0000Z...DISSIPATED

[BG918]

Tropical Storm Irene has formed in the eastern Caribbean. Moving toward Puerto Rico and Hispaniola, where it could be torn apart by the mountains. If it stays together it could possibly impact Florida or even go into the Gulf; a lot of uncertainty right now.

[jn1780]

Hurricane Irene isn't expected to hit Hispaniola as much as expected. Shes going to just barely hit the northern side which is the least mountainous side. Anyone from North Carolina to Florida could get hit by a major hurricane by the beginning of next week. Best hope now is that she curves out to sea or goes more to the west and hits more land and mountains.

[BG918]

Hurricane Irene could cause some major problems along the East Coast this weekend. Depending on the track Washington, Philadelphia, NYC and Boston could all experience strong winds, rain and storm surge.

[adaniel]

Just saw this on another forum I frequent:

FWIW, the new 12Z European model has the worst case scenario for NYC... basically Irene makes landfall as a roughly strong category 3 in Cape May, NJ while heading N/NNE just over or to the left of NYC as a very large category 2... the storm surge from such a storm would be beyond imaginable considering the funneling effect of the coastline near New York.

Fortunately it is just one model, and there is still enough time for the path to change from that (though the European model is generally the most accurate)

Yikes.

[dmoor82]

I heard on the Weather Channel,that the last Major hurricane to hit NYC caused 13ft' storm surges!

[BG918]

It will be close regardless. The models have been trending toward taking Irene further east toward Cape Cod though. NYC getting slammed would be one of those worst case scenarios, just like Katrina was with New Orleans.

[jn1780]

Now the models seem to be trending back west. The NHC puts long island in the bulls eye. This far out it will most likely be wrong of course.

[venture]

Sorry for not being able to chime in on the first major hurricane of the season, and one that will be posing a significant risk to the mainland. It does appear things are shifting back west some, but the main thing that has been stable is that this will likely have significant impacts on New England...if not also the Mid Atlantic area.

[BG918]

The NC Outer Banks will take a direct hit Saturday morning. Depending on how much the hurricane interacts with land will impact how much it weakens as it heads up the mid-Atlantic toward New England. Most models are still showing another landfall at Long Island and hurricane conditions in NYC by Sunday morning. All of NYC will likely be in a Hurricane Warning by the afternoon.

[ou48A]

The new threat.
Will this make the GOM?

http://www.wunderground.com/tropical.../at201112.html

[venture]

Doesn't look like it, but way too early to say. GFS is taking it WNW and then eventually NW with a landfall as a Cat 2/3 storm in the Maritime Provinces of Canada. However, that is a pretty unusual track for a storm, so we'll see if it even happens.

We do have what appears to be an active period coming for the Gulf though. The only problem...the front coming through next weekend will likely end up keeping any moisture south of Oklahoma completely. It appears there could be as many as 2 on going tropical cyclones (low end TS or TD systems) on going at the same time in the Gulf start later this week and through the following week. It looks like for the most part, the forecast will be mostly dry in Oklahoma for the next 2-3 weeks. Though some scattered/isolated storms possible here and there - and with the frontal passage - that will help out slightly in areas that get lucky.

At the end of the day, we are still in the 2nd driest 365-day period in recorded history and any rain we get over the next two weeks will do virtually nothing to stop the drought. We need a good long soaking rain...and it isn't showing up yet.

[BG918]

This is one to watch in the Gulf:


Just a tropical wave right now but could develop into a depression in the next couple days. I don't see it coming our way though with the front moving through Saturday but there is at least a chance.

[ou48A]

A large area of disorganized cloudiness and thunderstorms over the
southeastern gulf of mexico is associated with a trough of low
pressure. Upper-level winds are currently unfavorable for
development...but are forecast to become more conducive on
thursday...and this system could become a tropical depression
during the next day or so. This system has a high chance...60
percent...of becoming a tropical cyclone during the next 48 hours
as it moves slowly northwestward. Interests along the entire
northern gulf of mexico coast should monitor the progress of this
disturbance.

[BG918]

Look at that latest model run at 1800 on 8/31. Safe to say the models don't know what this system will do at this point.

Nothing is pushing it very far northward.

[Thunder]

Oklahoma needs Hurricane Lee!!!

[venture]

Morning model run really shows things will be pretty complicated with the Gulf system. It looks like the only thing that can be guaranteed right now is that a strong tropical storm (possibly weak hurricane) will develop along the TX/LA gulf coasts. This system will bounce around the coast a bit and may have a couple different landfalls. However, a front will be moving south and should keep it from getting too far inland. Then we have the model split with half taking it to the NE over the SE USA and others taking it SW into Mexico and the system dying out there.

Right now, the chance for any impact on Oklahoma looks extremely low to almost nothing.

[BG918]

Maybe we can get some rain from Katia late next week....

[sacolton]

Keep watch on KATIA. It is making a direct-course to the east coast and with plenty of time to develop into a Cat. 4 or Cat. 5 hurricane by SEPTEMBER 11, 2011.

[SoonerDave]

http://news.brevardtimes.com/2011/09...a-changes.html

Looks like it might be making a turn more toward the SE US, but it sure seems like it would be prone (eventually) to spin back out to sea, it would seem...

[venture]

Keep watch on KATIA. It is making a direct-course to the east coast and with plenty of time to develop into a Cat. 4 or Cat. 5 hurricane by SEPTEMBER 11, 2011.

Did Thunder get cloned without his knowledge? lol

Enough with the fake hype. All models (okay, except 2 or 3) indicating Katia will likely turn North then North East in 6-7 days before it even gets close to the US. There is also a front coming off the coast here at the end of the holiday weekend that will help steer it away.

[venture]

Random neat looking image.

[BG918]

Latest model run for TD 13/TS Lee are showing more of a westward turn and two models take the system into Arkansas by Labor Day. NHC is sticking with movement to the NE into Alabama and Georgia early next week. Louisiana will get plenty of rain it appears. We need it to move northwest....

[venture]

Nice little website to use for people that wonder where most the graphics come from: http://spaghettimodels.com/

[venture]

Latest model run for TD 13/TS Lee are showing more of a westward turn and two models take the system into Arkansas by Labor Day. NHC is sticking with movement to the NE into Alabama and Georgia early next week. Louisiana will get plenty of rain it appears. We need it to move northwest....

Be careful about relying on plots that don't have a very widespread model selection. The following graphic shows why NHC has the forecast continuing to go NE once it finally decides to wobble on shore.