QuikSCAT satellite showing its age; ASCAT satellite helping out

By: Dr. Jeff Masters , 2:48 PM GMT on December 05, 2007

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The now-famous QuikSCAT satellite, which measures winds at the ocean surface world-wide twice per day, was launched in 1999, and has now exceeded its expected lifetime by several years. A reminder of this satellite's age came during the week of November 21-28, when one of the cells on the satellite's battery went bad, forcing engineers to shut off data gathering on the satellite for about 10-15 minutes as it crossed over land in the Arctic. As a result, QuikSCAT provided only half of its usual data on winds and sea ice in the Arctic during that week. Fortunately, engineers were able to swap in a spare battery cell on November 28, and QuikSCAT is now back at full operation. This is good news, since QuikSCAT is a huge help for marine forecasts, sea ice forecasts, and predictions of tropical storms.

QuikSCAT now has help. An important new source of QuikSCAT-like data has been made available by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT). They launched their first polar-orbiting satellite, Metop-A, in October 2006, and declared the satellite ready for routine operations as of May 2007. This satellite carries a scatterometer called ASCAT which, like QuikSCAT, measures the winds at the ocean surface. ASCAT doesn't "see" the Earth's surface as well as QuikSCAT can--ASCAT sees chunks of the surface 25 km by 25 km, while QuikSCAT has a resolution twice as good--12.5 km. In addition, ASCAT only sees 60% of what QuikSCAT sees of the Earth's surface--QuikSCAT sees a swath of ocean 1800 km wide, while ASCAT sees two parallel swaths 550 km wide, separated by a 720 km gap. I found it frustrating to use ASCAT much this hurricane season, since it seemed that the passes missed the center of circulation of a storm of interest about 75% of the time.


Figure 1. Comparison of the coverage pattern of the QuikSCAT and ASCAT satellites, from December 4, 2007. Image credit: NOAA.

However, ASCAT has an important advantage--it can measure ocean surface winds where heavy rain is occurring, something QuikSCAT cannot. Both instruments carry an "active" radar (also called a scatterometer)--an instrument that emits a pulse of microwave energy that bounces off the ocean surface and returns to the satellite. The amount of microwave energy bounced back to the instrument is inversely proportional to how rough the sea surface is, and one can compute the wind speed and direction at the ocean surface based on this information. QuikSCAT uses microwave energy with a wavelength of about 2 cm (Ku-band), which is significantly affected by heavy rain. Microwave radiation from ASCAT uses a wavelength of about 5 cm (C-band), which is much less affected by rain. Thus, ASCAT can retrieve winds more accurately in the heavier precipitation environments such as those found in hurricanes. However, QuikSCAT does have finer spatial resolution and better sensitivity to high winds than ASCAT. Another minor advantage of ASCAT is that the winds across the entire swath of ocean it looks at are of uniform accuracy. QuikSCAT, on the other hand, has a bit larger errors at the edge of its 1800 km-wide swath, and in the middle, making it more difficult to interpret the data in some cases.

QuikSCAT data is routinely ingested into all of the major computer models that forecast hurricanes. ASCAT data is not yet used in this way, since ASCAT is currently still in its calibration and validation phase. However, by the 2008 hurricane season, ASCAT data will probably be used in this fashion. Having ASCAT to complement QuikSCAT will be a big help to NHC forecasters, particularly for those storms far out at sea where the Hurricane Hunters cannot reach.

ASCAT data is available from the ASCAT web page. QuikSCAT expert Dr. Paul Chang of NOAA also has ASCAT data available on his NOAA Marine Observing Systems web page.

Next blog
This Friday, the Colorado State University team issues its first forecast for the 2008 Atlantic hurricane season. I'll present an analysis of the forecast Friday afternoon.

Jeff Masters

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219. flaboyinga
6:28 PM GMT on December 17, 2007
Patrap, and StormW, Mail call.
218. flaboyinga
6:26 PM GMT on December 17, 2007
Merry Christmas to everyone. I hope the new year treats you great. I've been tied up a lot with my family and extended family and have stuck to lurking in the pantry. (Some of us are old enough to remember the La Choy cooked in dragon fire commercials.) I got my taste of Global Warming last night and more is expected here in SE Ga. It's probably warm over at St. Simon's Island, tho.lol I hope everyone is having a blessed day. Back to lurking.
217. NEwxguy
6:55 PM GMT on December 07, 2007
Hope we get a little break soon,hate this continous cold weather.My prediction is its going to stay wintery until the middle of January.
Member Since: September 6, 2007 Posts: 886 Comments: 15950
216. LakeShadow
6:46 PM GMT on December 07, 2007
Yeah things are pretty quiet on the radar now...take it when I can get it. Its supposed to warm up a little. They keep changing the day that the warm-up is coming. was Fri then Sat, then Sun, so I see it posted for Tues... ugh. And thats only to 40 deg.
April cant come soon enough!
Member Since: August 10, 2007 Posts: 3 Comments: 2134
215. NEwxguy
6:17 PM GMT on December 07, 2007
Im expecting a little light snow before the afternoon is over,but shouldn't amount to much
Member Since: September 6, 2007 Posts: 886 Comments: 15950
214. NEwxguy
6:15 PM GMT on December 07, 2007
212. LakeShadow 6:13 PM GMT on December 07, 2007
bone's about to get his dose pretty soon...
I think hes in NW NJ...

Yeh,most of the activity has been down toward his area.
Member Since: September 6, 2007 Posts: 886 Comments: 15950
213. NEwxguy
6:14 PM GMT on December 07, 2007
thats good,doesn't look like there will be much mechanism for getting it started in the near future,but the pattern is definitely going to be unsettled at least until the middle of next week.
Member Since: September 6, 2007 Posts: 886 Comments: 15950
212. LakeShadow
6:13 PM GMT on December 07, 2007
bone's about to get his dose pretty soon...
I think hes in NW NJ...



Link
Member Since: August 10, 2007 Posts: 3 Comments: 2134
211. LakeShadow
6:09 PM GMT on December 07, 2007
didnt really get kicked up last night around here...the wind shear is supposed to keep it light. not much right now, but still some showing up on the radar. very localized.
Member Since: August 10, 2007 Posts: 3 Comments: 2134
210. NEwxguy
5:58 PM GMT on December 07, 2007
afternoon lake,did the LES stop?
Member Since: September 6, 2007 Posts: 886 Comments: 15950
209. Natgas
5:47 PM GMT on December 07, 2007
206. tornadofan 4:54 PM GMT on December 07, 2007

Be careful of the two very popular weather terms El Nino and La Nina. They are as much TV hype terms as anything.
Member Since: October 26, 2007 Posts: 0 Comments: 0
208. LakeShadow
5:21 PM GMT on December 07, 2007
We had like 2 clippers this week. Some schools have been closed/delayed 2 or three times.

no offense, but better you than me :o)
And people move south to escape the cold... it will track you down, it will!

Afternoon, NE, Storm...everyone else..
merked out there for a while, children's breakdowns....
Member Since: August 10, 2007 Posts: 3 Comments: 2134
207. NEwxguy
5:15 PM GMT on December 07, 2007
206. tornadofan 4:54 PM GMT on December 07, 2007
204. NorthxCakalaky 4:36 PM GMT on December 07, 2007

Weak El Nino conditions in the equatorial Pacific Ocean are expected
to play a role in this winter's weather...

Did I miss something the past couple of weeks?
Member Since: September 6, 2007 Posts: 886 Comments: 15950
206. tornadofan
4:54 PM GMT on December 07, 2007
204. NorthxCakalaky 4:36 PM GMT on December 07, 2007

Weak El Nino conditions in the equatorial Pacific Ocean are expected
to play a role in this winter's weather...


HUH?
Member Since: April 5, 2007 Posts: 83 Comments: 12345
205. NEwxguy
4:42 PM GMT on December 07, 2007
SW,any long range signs of this winter pattern breaking down??
Member Since: September 6, 2007 Posts: 886 Comments: 15950
204. NorthxCakalaky
4:36 PM GMT on December 07, 2007
Current Severe Weather


Public Information Statement
Statement as of 7:00 am EST on December 7, 2007


The governors of Virginia and North Carolina have declared the week
of December 2nd to 8th... 2007 winter preparedness week. The National
Weather Service offices serving Virginia and North Carolina... in
cooperation with their respective departments of emergency
management... will send public information statements each day
through Saturday at approximately 7 am. These statements will focus
on different aspects of winter weather... and preparedness actions
the public should take for the upcoming winter season.

Today's topic: heavy snow.

For most of the last 10 Winters... temperatures have been normal to
above normal. What will this winter bring? The National Weather
Service outlook for this winter is calling for below normal
temperatures and near normal precipitation across the commonwealth.
Weak El Nino conditions in the equatorial Pacific Ocean are expected
to play a role in this winter's weather... by producing a stronger
than normal southern jet stream called the subtropical jet. Storm
systems intensifying rapidly along the eastern Seaboard during the
colder months of the year are usually responsible for producing most
of the heavy snows in our area.

These systems... called nor'easters... can also produce strong winds
which may result in blizzard conditions and huge snow drifts. Heavy
snow tends to occur 100 to 150 miles to the northwest of the track
of the surface low. Snow amounts well in excess of 30 inches have
occurred with nor'easters in our area. In addition... strong winds
and very cold temperatures can result in blizzard or near blizzard
conditions... dangerous wind chill values... and have resulted in snow
drifts up to 12 feet high.

The exact track the surface low pressure takes and how much cold air
is in place ahead of the system... determines if and where heavy snow
will occur. Given that cold air is in place... a surface low that
travels a hundred miles or so off the coast can produce some snow in
the central portion of Virginia and North Carolina... with the
potential for heavy snow confined to the eastern portions of the
area. If the surface low travels along the coast or slightly
inland... heavy snow is most likely in the northwestern one third of
Virginia.

If the amount of cold air in place is marginal for snow... it is
possible that heavy wet snow could occur in the higher elevations
with just a cold rain in the lower elevations. Heavy snow is capable
of bringing down tree limbs and power lines which may result in
power outages. In rare instances... heavy snow may result in the
collapse of roofs of buildings and homes. In addition... heavy snow
may result in snow covered or ice covered roads. This typically
leads to vehicle accidents and potentially major traffic jams. If
there is enough heavy snow and... or wind... some roads may be closed
and other roads may only be successfully traversed by 4 wheel drive
vehicles.

The following is a summary of historic snowstorms in virginia:

February 14-18 2003. 7 to 36 inches of snow across central and
northern Virginia (highest far north)... significant ice southern
Virginia.

January 24-25 2000. 6 to 19 inches of snow across much of central
and eastern Virginia.

January 6-7 1996. 12 to 30 inches of snow in much of
western... central... and northern Virginia. A few locations in the
mountains received over 3 feet of snow. Twenty four hour snowfall
records were established at Roanoke and Lynchburg. In
Virginia... there was one fatality directly attributed to the storm.
In the mountains... strong winds on January 8th created snow drifts
up to 10 feet high.

March 12-15 1993. 20 to 30 inches of snow with some amounts over 3
feet in the mountains. In the foothills... 10 to 18 inches of snow
fell. In Virginia... there was one fatality directly attributed to
the storm. In the mountains... strong winds up to 50 mph whipped
drifts up to 12 feet high and created near blizzard conditions.

February 10-12 1983. 10 to 20 inches of snow in a large portion of
Virginia with up to 30 inches of snow in northern portions of the
state. The storm established 24 hour snowfall records at
Roanoke... Lynchburg... and Richmond.

March 5-8 1962. 10 to 24 inches of snow in many interior portions of
Virginia.

Being prepared means making good decisions based on information
contained in outlooks... watches... warnings... advisories... other
statements and forecasts from the National Weather Service. The key
is to know what to do in advance. If a winter storm like what
occurred in 1993 or 1996 was predicted to hit Virginia in two
days... what would you do between now and when the storm arrives to
get ready? You should make sure you have enough food... water and
medication for several days. You also need to be prepared for the
loss of power and... or heat.

Up to date weather information is available at:

Www.Weather.Gov/Blacksburg

The National Weather Service winter weather awareness home Page is
found here:




" " " " " " " " " " " " "" " " "

Much of N.C schools systems are under a 2 hour delay/closed where I live.Not one weather station predicted ice/snow.Though weatherunderground said a 20% of freezing rain above 3000f.t. We had ice down around 1000f.t and below.

When the met came on air this morning he said the "Alberta Clipper diped more south than expected".None of the roads were treated this morning with salt.

We had like 2 clippers this week. Some schools have been closed/delayed 2 or three times.
202. NEwxguy
4:22 PM GMT on December 07, 2007
morning SJ, doing well up here,but cold.
Member Since: September 6, 2007 Posts: 886 Comments: 15950
201. taistelutipu
4:22 PM GMT on December 07, 2007
Good afternoon everyone,

Daman seems to undergo an eyewall replacement cycle, the structure as become quite asymetrical over the past hours. In the first frames of the water vapor loop you can still see the former well-organized storm with a clear eye which collapses in the next frames. At the end of the loop I think I see a new eye forming. I'll be out for some hours now, let's see how Daman looks like then.
I'm quite happy that the cyclone did not take the forecast track over the island but seems to miss it. This one is really unpredictable. Yesterday the forecast still called for a passage between the two bigger islands, then it had the storm going over the island and now it circles it to the east.
Member Since: August 20, 2007 Posts: 12 Comments: 640
200. NEwxguy
4:22 PM GMT on December 07, 2007
Thanks Storm,good analysis as always.
Member Since: September 6, 2007 Posts: 886 Comments: 15950
199. StormJunkie
4:20 PM GMT on December 07, 2007
Morning NE and SW, hope y'all are well.
Member Since: August 17, 2005 Posts: 26 Comments: 16874
198. StormJunkie
4:19 PM GMT on December 07, 2007
Yep, I think so press, and good to see you around. Shoot me a WU mail though just in case.

Morning Ike, good to see you too.
Member Since: August 17, 2005 Posts: 26 Comments: 16874
197. NEwxguy
4:19 PM GMT on December 07, 2007
GM all.
Member Since: September 6, 2007 Posts: 886 Comments: 15950
195. presslord
4:08 PM GMT on December 07, 2007
stormj....things are lightening up...let's get together soon....Still have my #?
Member Since: August 13, 2007 Posts: 0 Comments: 10492
194. presslord
4:07 PM GMT on December 07, 2007
yea IKE...I've already started shuttering the windows and gassing up the cars....
Member Since: August 13, 2007 Posts: 0 Comments: 10492
193. LakeShadow
4:07 PM GMT on December 07, 2007
cool, lawntonliookers, let me know how you do.
:o)
snowcounting is a fun way to deal with the snow...
Member Since: August 10, 2007 Posts: 3 Comments: 2134
192. lawntonlookers
3:56 PM GMT on December 07, 2007
This is the most recent forcast map from Figi. Sounds like it could be another big storm.

LakeShadow, I tried you snow formula for Harrisburg, PA and will see how it works. I will keep you posted.

Figi
Member Since: March 22, 2006 Posts: 9 Comments: 1570
191. IKE
3:53 PM GMT on December 07, 2007
FORT COLLINS, Colorado (AP) -- Hurricane forecaster William Gray called Friday for seven Atlantic hurricanes, three of them major, during the 2008 season.

Yawn.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
190. LakeShadow
3:34 PM GMT on December 07, 2007
pardon,, Daman...I miss read..I thought he might be named after the evil kid in OMEN..
Member Since: August 10, 2007 Posts: 3 Comments: 2134
189. LakeShadow
3:32 PM GMT on December 07, 2007
morning...slow again...
Damian is big...Nice evil name for an evil storm... :O
Member Since: August 10, 2007 Posts: 3 Comments: 2134
188. StormJunkie
3:30 PM GMT on December 07, 2007
Im really curious what they went through to make this all happen.

Welcome aboard 711!

My guess would be that it was all done electronically. That is one of the beauties of space exploration. The contingency plans are pretty well thought out during development of things like the QS. Again, all just my guess.
Member Since: August 17, 2005 Posts: 26 Comments: 16874
187. sydneyaust1
3:10 PM GMT on December 07, 2007
oops!! that would be 1 Hour and 25 Mins ago
186. sydneyaust1
3:04 PM GMT on December 07, 2007
Issued 25 Mins ago

Special Weather Bulletin Number TWENTY for Fiji ON SEVERE TROPICAL
CYCLONE DAMAN
ISSUED FROM RSMC NADI at 1:48am on Saturday the 8th of December 2007

TROPICAL CYCLONE WARNING

A HURRICANE WARNING REMAINS IN FORCE FOR CIKOBIA, NORTH-EASTERN PARTS
OF VANUA LEVU AND NEARBY ISLANDS.
A STORM WARNING IS IN FORCE FOR KIA, THE REST OF EASTERN HALF OF
VANUA LEVU, TAVEUNI AND NEARBY ISLANDS, NORTHERN AND CENTRAL LAU
GROUP.
A GALE WARNING IS IN FORCE FOR THE SOUTHERN LAU GROUP.

SEVERE TROPICAL CYCLONE DAMAN CENTRE 935HPA [CATEGORY 4] WAS LOCATED
NEAR 15 DECIMAL 7 SOUTH 180 DECIMAL 0 EAST OR ABOUT 110 KILOMETRES
NORTHEAST OF LABASA AT 1.40AM TODAY. CLOSE TO ITS CENTRE, THE CYCLONE
IS ESTIMATED TO HAVE AVERAGE WINDS UP TO 160 KM/HR WITH MOMENTARY
GUSTS UP TO 240 KM/HR. THE CYCLONE IS NOW MOVING EAST-SOUTHEAST AT
ABOUT 20 KM/HR AND EXPECTED TO CURVE TOWARDS THE SOUTHEAST.

FOR CIKOBIA, NORTH-EASTERN PARTS OF VANUA LEVU AND NEARBY ISLANDS,
WINDS OF VERY DESTRUCTIVE HURRICANE FORCE WITH AVERAGE SPEEDS UPTO
160 KM/HR WITH MOMENTARY GUSTS TO 240 KM/HR.

FOR KIA, THE REST OF EASTERN HALF OF VANUA LEVU, TAVEUNI AND NEARBY
ISLANDS, NORTHERN AND CENTRAL LAU GROUP, WINDS INCREASING TO
DESTRUCTIVE STORM FORCE WITH AVERAGE SPEEDS UPTO 110 KM/HR WITH
MOMENTARY GUSTS TO 160 KM/HR TOMORROW.

OVER THE SOUTHERN LAU GROUP, WINDS INCREASING TO DAMAGING GALE FORCE
OF 65 KM/HR WITH MOMENTARY GUSTS TO 110 KM/HR FROM LATER TOMORROW.

EXPECT HEAVY RAIN AND SQUALLY THUNDERSTORMS ESPECIALLY OVER THE
EASTERN HALF OF THE COUNTRY. FLASH FLOODING OF LOW-LYING AREAS,
RIVERS AND STREAMS. SEA FLOODING OF LOW-LYING COASTAL AREAS,
ESPECIALLY AT THE TIME OF HIGH TIDE.

FOR THE REST OF FIJI SOME SHOWERS WITH ISOLATED THUNDERSTORMS. ROUGH
SEAS. MODERATE TO HEAVY SWELLS.

FOR ROTUMA.
NORTH TO NORTHWEST WINDS FRESH AND GUSTY. CLOUDY PERIODS WITH
OCCASIONAL SHOWERS AND A FEW SQUALLY THUNDERSTORMS. ROUGH SEAS.
MODERATE TO HEAVY SWELLS.


The following information is provided especially for the mariners:
EXPECT WINDS OF VERY DESTRUCTIVE HURRICANE FORCE WITHIN 25 MILES OF
CYCLONE CENTRE WITH PHENOMINAL SEAS. DESTRUCTIVE STORM FORCE WINDS
WITHIN 40 MILES OF CENTRE WITH VERY HIGH SEAS. DAMAGING GALE FORCE
WINDS TO 60 MILES WITH VERY ROUGH TO HIGH SEAS. DAMAGING HEAVY
SWELLS.

THE NEXT SPECIAL WEATHER BULLETIN FOR FIJI WILL BE ISSUED AROUND 5AM
TODAY.
185. weatherboyfsu
2:45 PM GMT on December 07, 2007
Good morning,

Isnt it amazing how below the equator the spin is the opposite. It kind of gives you a headache to look at when your so use to looking at Northern hemisphere storms. Very intense storm.
Member Since: July 17, 2005 Posts: 0 Comments: 1025
184. Ronald711
2:29 PM GMT on December 07, 2007
engineers were able to swap in a spare battery cell on November 28

Im curious how this was done? Its a satellite, I would they they would either have to go have NASA do something with it, or launch a new satellite. Unless there is something they did electronically by sending commands from a ground station, which the article doesn't make it sound like.. Im really curious what they went through to make this all happen.
Member Since: February 18, 2003 Posts: 9 Comments: 2
183. aspectre
2:15 PM GMT on December 07, 2007
Chicklit "...main island...flight scheduled...on Monday. ...asking if...delayed."

NadiInternationalAirport is 59feet/18metres above sealevel and Fiji is regularly hit by TropicalCyclones, so I'd suspect structures have been engineered to resume normal flight operations very quickly after the equivalent of a moderate Cat.3 hurricane has passed.
In fact, Daman appears to be bypassing the main island Suva entirely...

...and the airport should remain unaffected.
Member Since: August 21, 2007 Posts: 0 Comments: 4860
182. StormJunkie
1:27 PM GMT on December 07, 2007
Morning all, good to see ya JFla, and Chick ☺

Just made a trip through Florida and have some pics posted in my blog for those who are interested.

JFla, what kind of interesting for the SE?
Member Since: August 17, 2005 Posts: 26 Comments: 16874
180. Chicklit
11:28 AM GMT on December 07, 2007
My brother in law is on the main island and has a flight scheduled out of there for England on Monday. My sister is asking if he'll be delayed. Anybody have an idea?
Member Since: July 11, 2006 Posts: 14 Comments: 11390
179. aspectre
10:06 AM GMT on December 07, 2007
The Australian Scale is based on the maximum speed of wind gusts rather than sustained winds.
Category 5 means gusts equal to or greater than 280kilometres per hour / 174miles per hour
and is more weakly associated with sustained winds equal to or greater than 200kph/124mph

"SevereTropicalCyclone Daman...(Category4)...is estimated to have average winds up to 180kph with momentary gusts up to 260kph" from RSMC-Nadi (Fiji Meteorological Service)
means sustained winds of ~112mph with gusts up to ~162mph
which would be a weak Cat.3 hurricane on the Saffir-Simpson scale.

"Max sustained winds - 105knots , gusts - 130knots" for Daman from the JointTyphoonWarningCenter
means sustained winds of ~121mph/~194kph with gusts up to ~150mph/~241kph
which would be a moderate Cat.3 hurricane on the Saffir-Simpson scale.
Member Since: August 21, 2007 Posts: 0 Comments: 4860
178. HadesGodWyvern (Mod)
9:22 AM GMT on December 07, 2007
JTWC advisory for Daman
Member Since: May 24, 2006 Posts: 51 Comments: 46163
177. HadesGodWyvern (Mod)
9:02 AM GMT on December 07, 2007
TROPICAL CYCLONE DAMAN ADVISORY NUMBER NINE - ISSUED AT 8:30AM UTC
====================================

SEVERE TROPICAL CYCLONE DAMAN [925 hPa] located near 15.5S 178.7E as of 0600 AM UTC. Position Good based on radar, Hourly MTSAT Enhanced Infrared Radar Imagery with animation. Cyclone has 10 minute sustained winds of 100 knots and is moving east at 8 knots.

Hurricane Force Winds
=====
30 NM from the center

Storm Force Winds
=====
50 NM from the center

Gale Force Winds
====
65 NM from the center

Additional Information
=======================
Eye now embedded and not clearly discernible. Shear over the system increased significantly past 6 hours. SST 28-30C. Organization steady. Convective bands though beginning to lose organization. Dvorak Based on Embedded Center Pattern with B Surround and 0.5 Banding, Yielding a DT 5.5, PT=5, Met=5 Thus T5.5/6.0/D1.5/24 HRS.

Cyclone is steered east by a mid level ridge to the north. Global models generally agree on an easterly then southeast track with little intensification.
Member Since: May 24, 2006 Posts: 51 Comments: 46163
172. HadesGodWyvern (Mod)
7:26 AM GMT on December 07, 2007
HURRICANE WARNING NUMBER ELEVEN

Severe Tropical Cyclone DAMAN [CAT 4]
15.5S 178.7E - 100 knots 925 hPa

moving eastward at 8 knots, eventually turning southeast

Hurricane Force Winds
====
30 miles from the center

Storm Force Winds
=====
50 miles from the center

Gale Force Winds
====
90 miles from the center


This warning replaces Hurricane Warning number 10

Tropical Disturbance Advisory will be issued at 8:30 AM UTC
Member Since: May 24, 2006 Posts: 51 Comments: 46163
170. HadesGodWyvern (Mod)
7:12 AM GMT on December 07, 2007
Joint Typhoon Warning Center

Tropical Disturbance Summary (0630z 07Dec)
=========================================
An area of convection persistent near 9.4S 87.3E or 890 NM east of Diego Garcia. Animated Multispectral Imagert and SSMIS Microwave Image indicates a persistent area of deep convection banding wrapping into a well defined low level circulation center. The convective banding is displaced to the southwest by moderate vertical winds shear from the northeast. Good outflow along with favorable ocean heat content has fueled the deep convection of the disturbance.

The moderate vertical wind shear is the main limiting factor of any further development. The maximum sustained winds near the center is 15-20 knots with a minimum sea level pressure of 1007 mb. The potential of this disturbance to form into a significant tropical cyclone within the next 24 hours is POOR.
Member Since: May 24, 2006 Posts: 51 Comments: 46163

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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