ATL: Ex Tropical Storm EARL - Discussion

[AJF0602]

I'm no meteorologist but I just feel like this thing could take us all by surprise. Right now i'm in Greenville, NC which is 90 miles away from the coast and I attend ECU. They released a statement earlier saying they are monitoring the situtation but won't make a decision until after 2 pm... by then it would be too late. Many of us including me actually live on the coast.

[senorpepr]

stupid satellite eclipse period

Please explain.

Near the equinox (spring and fall), the satellite enters the "eclipse" period. Essentially, the satellite becomes eclipsed from the sun and doesn't keep enough solar power to get it through the night. So, during this eclipse period, there is a period of time in the middle of the night that we lose geostationary satellite imagery. Once we get a little closer to sunrise, the satellite will resume operations.

From NOAA:
What is a satellite eclipse period?
Since GOES is in a geosynchronous orbit, the sun will yearly traverse a +/- 23.5 degree angle perpendicular to the Earth's equator (GOES orbit plane). As a result, near the Vernal and Autumnal Equinoxes the Earth disk will periodically occult the sun, from a GOES perspective. Essentially, there are two eclipse seasons for each GOES spacecraft. Each eclipse season spans a 48-day period, symmetric around the equinox and the sun occultation lasts for a maximum of 72 minutes/day during the equinox. Each GOES spacecraft utilizes a solar array that converts sunlight into electricity in order to power the satellite. Each day during the eclipse season the sun is blocked by the Earth and sunlight is not available to the GOES solar array. Therefore, the energy needed to power the instruments is not available and the instruments are powered off. There is typically a 0-3 hour outage of imagery each day as GOES progresses through eclipse season. The maximum outage of 3 hours will occur at or near the equinox.

GOES-13 will experience the eclipse from 8/14/10 to 10/28/10. For times, look at http://www.ssd.noaa.gov/PS/SATS/GOES/EA ... -Rout.html

[toto]

senorpepr, thanks for the explanation

[xironman]

Sounds like a nasty ride

Remarks Section - Additional Remarks...
FREQUENT SVR TURBC NW EYEWALL TO 10 NM FURTHER OUT.

[baitism]

I think dry air prevented Earl from really bombing out.

[SunnyThoughts]

[ncweatherwizard]

Most interesting is the westward shift of the guidance at 48 hours. We've been expecting the center to stay offshore and for Cape Cod to experience hurricane force conditions anyway. New TVCN consensus sits over Nantucket Island and is about 70nm from Boston at closest approach. Models, of course, might shift back to the east in the morning; in the grand scheme of things they haven't shifted that much. But if the 12Z runs stay that close to MA, then I'd expect a Hurricane Warning for more than just Cape Cod. Where to put it is a difficult decision given the uncertainty concerning how the wind field will expand. How many times do you have a potential opportunity to issue a Hurricane Warning for Boston Harbor?

Main thing is for folks to not panic and make their last minute stock up preparations today. Somebody's power is going to be out for a few days.

[NC George]

I'm no meteorologist but I just feel like this thing could take us all by surprise. Right now i'm in Greenville, NC which is 90 miles away from the coast and I attend ECU. They released a statement earlier saying they are monitoring the situtation but won't make a decision until after 2 pm... by then it would be too late. Many of us including me actually live on the coast.

I work in Greenville, live in nearby Ayden. The majority of OBX hurricanes are a non-event in Greenville. The ones that affect us are the ones that make landfall between Wilmington and Morehead City. We are 110 miles inland from Cape Hatteras. While some (a few) students may commute from the coast, the vast majority live in Greenville or Pitt County. I'm sure you will be excused from class if you have to stay home due to the hurricane, but you would probably be safer if you stay in Greenville for the night as opposed to going back to the coast Thursday afternoon. There is no reason to cancel class Thursday for a few students when there is no danger to 99% or more of the students, especially since any effects are likely to begin later in the evening.

That being said, in Floyd the worst band to pass through Greenville, the one that inundated Pitt County, actually passed through before Floyd made landfall near Wilmington. It did get bad really quick. I left for work around 5 and everything was fine, came home about 2-3 hours later and everything was flooded. There were worse bands later wind wise, but as far as rain that first band was the back-breaker. Of course, remember the creeks and streams were already at the top of their banks from Dennis, while today all the creeks and streams are barely trickling. I was attending ECU at the time, and we got nearly 2 weeks off from school and we didn't have to make it up.

I expect we will see a blustery day tomorrow, but I'm not expecting anything serious.

[baitism]

Looks like Earl is weakening; not totally unexpected.

[gotoman38]

Looks like Earl is weakening; not totally unexpected.

Nope - pressure down to 929 - he's still getting stronger

[Infdidoll]

I talked to some fellow military friends in Jacksonville, North Carolina who were discussing whether they were going to have to evacuate or not, earlier. I don't usually watch the ATL much since we're stationed in Japan, but wanted to let you guys know that our thoughts and prayers are with you all. Looks like a pretty frightening storm to be faced with and I trust you all will make the best decisions for yourself and your families. When in doubt, get the heck out! Especially if you live in a flood zone or a weak-walled wooden structure.

Please be safe! And send some of those hurricanes our way...we're half bored over here in the WPAC! (only kidding)

[Meso]

Definitely not weakening:

MAX OUTBOUND AND MAX FL WIND 141 KT NE QUAD 07:10:50Z

[supercane]

Near the equinox (spring and fall), the satellite enters the "eclipse" period. Essentially, the satellite becomes eclipsed from the sun and doesn't keep enough solar power to get it through the night. So, during this eclipse period, there is a period of time in the middle of the night that we lose geostationary satellite imagery. Once we get a little closer to sunrise, the satellite will resume operations.

From NOAA:
What is a satellite eclipse period?
Since GOES is in a geosynchronous orbit, the sun will yearly traverse a +/- 23.5 degree angle perpendicular to the Earth's equator (GOES orbit plane). As a result, near the Vernal and Autumnal Equinoxes the Earth disk will periodically occult the sun, from a GOES perspective. Essentially, there are two eclipse seasons for each GOES spacecraft. Each eclipse season spans a 48-day period, symmetric around the equinox and the sun occultation lasts for a maximum of 72 minutes/day during the equinox. Each GOES spacecraft utilizes a solar array that converts sunlight into electricity in order to power the satellite. Each day during the eclipse season the sun is blocked by the Earth and sunlight is not available to the GOES solar array. Therefore, the energy needed to power the instruments is not available and the instruments are powered off. There is typically a 0-3 hour outage of imagery each day as GOES progresses through eclipse season. The maximum outage of 3 hours will occur at or near the equinox.

GOES-13 will experience the eclipse from 8/14/10 to 10/28/10. For times, look at http://www.ssd.noaa.gov/PS/SATS/GOES/EA ... -Rout.html

Not quite true as stated as I understand. As I discussed in this thread, GOES-13 (East) is not affected by eclipse, because larger batteries were installed in the GOES N/O/P (GOES 13=GOES N) to maintain power during eclipse. There are still outages, however, related to the Stray Light Exclusion Zone (SLZ), the times around the eclipse period when the sun contaminates imagery.

[bob rulz]

I know that Earl is likely pretty close to peak intensity at this point and is only gradually strengthening, but theoretically if it were to reach cat 5 intensity (and again, I realize that's not likely), it would be the furthest north cat 5 on record in the Atlantic basin.

[baitism]

Definitely not weakening:

MAX OUTBOUND AND MAX FL WIND 141 KT NE QUAD 07:10:50Z

Sat images would suggest otherwise. Probably downhill from here.

[senorpepr]

Not quite true as stated as I understand. As I discussed in this thread, GOES-13 (East) is not affected by eclipse, because larger batteries were installed in the GOES N/O/P (GOES 13=GOES N) to maintain power during eclipse. There are still outages, however, related to the Stray Light Exclusion Zone (SLZ), the times around the eclipse period when the sun contaminates imagery.

Thank you for clearing that up... yes, G13 still has some outages, but it's nothing like the data stops we had with the previous generation of GOES. (I need my morning coffee... )

[Brent]

Winds up to 145 mph at 5am

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

A HURRICANE WATCH HAS BEEN ISSUED NORTH OF SAGAMORE BEACH
MASSACHUSETTS TO PLYMOUTH MASSACHUSETTS...AND WEST OF WOODS HOLE
MASSACHUSETTS TO WESTPORT MASSACHUSETTS.

A TROPICAL STORM WARNING HAS BEEN ISSUED FOR THE COAST OF LONG
ISLAND NEW YORK FROM FIRE ISLAND INLET NORTHWARD AND EASTWARD TO
PORT JEFFERSON HARBOR.

A TROPICAL STORM WATCH HAS BEEN ISSUED NORTH OF PLYMOUTH
MASSACHUSETTS TO EASTPORT MAINE.

ENVIRONMENT CANADA HAS ISSUED A TROPICAL STORM WATCH FOR THE COAST
OF NOVA SCOTIA FROM PORT MAITLAND TO MEDWAY HARBOUR.

[Time_Zone]

Definitely not weakening:

MAX OUTBOUND AND MAX FL WIND 141 KT NE QUAD 07:10:50Z

Sat images would suggest otherwise. Probably downhill from here.

The storms fighing dry air right now....hence why he's not looking quite as good as he was a few hours ago. While that may affect the way he looks it doesn't mean hes weakening in fact it seems the complete oppisite is happening.

[dexterlabio]

The track seems to be a bit closer to the coast compared to yesterday's forecast.

[Brent]

NHC's graphic not updated yet

EARL IS LIKELY NEAR PEAK
INTENSITY AT THIS TIME...AS THE EYEWALL CONVECTION IS BECOMING A
LITTLE LESS ORGANIZED IN SATELLITE IMAGERY.

THE 48-72 HR TRACK HAS BEEN SHIFTED TO THE LEFT...BUT
STILL LIES ON THE RIGHT SIDE OF THE GUIDANCE ENVELOPE.