Subtropical Storm Andrea forms

By: Dr. Jeff Masters , 1:34 PM GMT on May 09, 2007

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Throw away the calendar, hurricane season is here! The Hurricane Hunters are in the air, and found that the intensifying storm of the Georgia coast had acquired enough organization to be called Subtropical Storm Andrea. Here's the special advisory put out by NHC at 9am:


Special tropical disturbance statement
905 am EDT Wed May 9 2007

Satellite imagery and preliminary reports from an Air Force Reserve reconnaissance aircraft this morning indicate that the area of low pressure centered about 150 miles east of Jacksonville is acquiring the characteristics of a subtropical cyclone. The system continues moving generally westward at about 5 mph. If present trends continue... advisories on subtropical storm Andrea would be
initiated later this morning.

Dangerous surf conditions continue along the coasts of the
Carolinas... Georgia... and northeastern Florida. Interests in these areas should continue to monitor products issued by local National Weather Service forecast offices.


Andrea has developed several bands of intense thunderstorm activity, well removed from the center. Tropical storm-force winds cover a wide swath of ocean surrounding the center. Winds from the 6:44am EDT pass of the QuikSCAT satellite (Figure 2) were as high as 50 knots (57 mph) in the heaviest thunderstorms on the southeast side. Winds overnight at buoy SKMG1 located about 60 miles off the Georgia coast were as high as 50 mph, gusting to 56 mph. These strong winds will continue to bring coastal flooding and significant beach erosion from North Carolina to northern Florida today.


Figure 1. Visible satellite image of Subtropical Storm Andrea shortly before it was named on May 9, 2007.


Figure 2. QuikSCAT image of the surface winds at 6:44am EDT Wed May 9. Image credit: NOAA/NESDIS.

Andrea is currently under about 10 knots of wind shear, but this shear is expected to increase to over 30 knots late tonight, so only a small window of time exists for the storm to intensify. Andrea is very unlikely to grow to hurricane strength, due to the combined effects of increased wind shear and cooler waters it will find near the coast. Landfall should occur Thursday morning over the region between northern Florida and southern South Carolina.

I'll have another update on Andrea this afternoon.
Jeff Masters

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306. hibiscus22
7:57 PM GMT on May 09, 2007
Can someone help me clear something up? For the past few years, I've always heard from the weather authorities that they only name tropical storms and hurricanes. And that is exactly what they had done. So why have they already jumped on naming this storm Andrea, when it isn't even a tropical storm? When I was a kid, I think they only names hurricanes. Last year my husband stated (only half joking) that he thinks they try to plow through the names as fast as they can to create hype and sensationalism. And then the media has more to feed on, and Jim Cantore has more opportunities to stand out in the driving rain wearing a blue rain slicker and using the word 'pounding' in every sentence. Fill me in if I am missing something. Thanks.
Member Since: August 8, 2006 Posts: 15 Comments: 215
305. IKE
6:05 PM GMT on May 09, 2007
NEW BLOG!
Member Since: June 9, 2005 Posts: 23 Comments: 37858
304. weatherboykris
6:02 PM GMT on May 09, 2007
Adrian...it confirmes EVERYONE'S thinking,LOL.Anyone with eyes can see this storm is weakening.But,and this is a big but,it has started to look bad this time of day each of the past three days;only to blow up overnight and look better than before.Will that happen again?Hard to say.We'll need to wait and see.It isn't ingesting that dry air,and shear isn't a problem yet.So,I'm thinking this is likely diurnal.Then again,what do I know?At midnight last night I was calling it dead in Taz's blog.
Member Since: December 9, 2006 Posts: 125 Comments: 11346
303. hurricane23
5:59 PM GMT on May 09, 2007
Cofirms my thinking!

SUBTROPICAL STORM ANDREA INTERMEDIATE ADVISORY NUMBER 1A
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012007
200 PM EDT WED MAY 09 2007

...POORLY-ORGANIZED SUBTROPICAL STORM MEANDERING OFF THE SOUTHEAST
U.S. COAST...


A TROPICAL STORM WATCH REMAINS IN EFFECT ALONG THE SOUTHEAST COAST
OF THE UNITED STATES FROM ALTAMAHA SOUND GEORGIA SOUTHWARD TO
FLAGLER BEACH FLORIDA. A TROPICAL STORM WATCH MEANS THAT TROPICAL
STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY
WITHIN THE NEXT 36 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE
INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED
BY YOUR LOCAL WEATHER OFFICE.

AT 200 PM EDT...1800Z...THE CENTER OF SUBTROPICAL STORM ANDREA WAS
ESTIMATED NEAR LATITUDE 30.9 NORTH...LONGITUDE 80.0 WEST OR ABOUT
100 MILES...160 KM...SOUTHEAST OF SAVANNAH GEORGIA AND ABOUT 135
MILES ...220 KM...NORTH-NORTHEAST OF DAYTONA BEACH FLORIDA.

ANDREA IS MOVING ERRATICALLY...BUT GENERALLY TOWARD THE WEST NEAR 3
MPH. A CONTINUED SLOW MOTION AND A GRADUAL TURN TOWARD THE
SOUTHWEST ARE EXPECTED DURING THE NEXT 24 HOURS. ON THIS
TRACK...THE CENTER OF ANDREA IS EXPECTED TO REMAIN JUST OFFSHORE OF
THE U.S. COAST THROUGH AT LEAST THURSDAY MORNING.

MAXIMUM SUSTAINED WINDS ARE NEAR 45 MPH...75 KM/HR...WITH HIGHER
GUSTS. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 24
HOURS.

WINDS OF TROPICAL STORM FORCE EXTEND OUTWARD UP TO 115 MILES...185
KM...MAINLY TO THE EAST OF THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB...29.62 INCHES.

SINCE THE HEAVIEST RAINS ASSOCIATED WITH ANDREA ARE EXPECTED TO
REMAIN OFFSHORE DURING THE NEXT 24 HOURS... ANDREA IS NOT EXPECTED
TO PRODUCE SIGNIFICANT RAINFALL OVER ANY LAND AREAS THROUGH AT
LEAST THURSDAY MORNING.

REPEATING THE 200 PM EDT POSITION...30.9 N...80.0 W. MOVEMENT
TOWARD...WEST NEAR 3 MPH. MAXIMUM SUSTAINED WINDS...45 MPH.
MINIMUM CENTRAL PRESSURE...1003 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
500 PM EDT.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
302. hurricane23
5:56 PM GMT on May 09, 2007
Posted By: GulfScotsman at 1:53 PM EDT on May 09, 2007. (hide)
Posted By: hurricane23 at 5:28 PM GMT on May 09, 2007.

Say bye to bye to andrea if this trend continues as convection is decreaseing and personally i think the NHC should have waited a tad longer but its to close to the coast so they had to take action.

Convection greatly decreasing


Patients young one..... patients.... time is on her side... this is a momentary fluctuation... expected....

Thanks still feel young at 29.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
301. hurricane23
5:55 PM GMT on May 09, 2007
If this system were in the middle atlantic no upgrade would have taken place but due to its proximity to the coast the NHC had to err on the side of caution.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
299. SavannahStorm
5:54 PM GMT on May 09, 2007
Patients? Is hurricane a doctor?
Member Since: September 22, 2005 Posts: 18 Comments: 2343
294. hurricane23
5:51 PM GMT on May 09, 2007
Its fighting off some dry air on the west side.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
292. weatherboykris
5:50 PM GMT on May 09, 2007
The new vortex report should be out soon...expect a rise in pressure.
Member Since: December 9, 2006 Posts: 125 Comments: 11346
291. TexasRiverRat
5:49 PM GMT on May 09, 2007
Could this do something in the GOM????
290. weatherboykris
5:48 PM GMT on May 09, 2007
It's not ingesting dry air...the thunderstorms are just collapsing.Either way,I agree with you.SSTs are barely sufficient now,and it will soon start upwelling some pretty cool water.
Member Since: December 9, 2006 Posts: 125 Comments: 11346
289. SavannahStorm
5:48 PM GMT on May 09, 2007
It'd be nice if the weather stations at the Navy Sea Towers off the Georgia coast would update. They haven't updated since 8:30 this morning, and they are the closest stations to the center.
Member Since: September 22, 2005 Posts: 18 Comments: 2343
288. hurricane23
5:47 PM GMT on May 09, 2007
The dry air is having here for lunch.This system will not be around by tommorow morning.Bouy observations and satelitte imagery confirm this.

g
Member Since: May 14, 2006 Posts: 8 Comments: 13804
287. TexasRiverRat
5:45 PM GMT on May 09, 2007
1 mb is equal to 2.088543 pounds/ft Sq.
626.53 = 300 mb
286. wantsnow
5:43 PM GMT on May 09, 2007
It is subtropical because it was not formed in the tropics. It was formed in the subtropical region of the globe which is that region just outside of the tropics. Se below...

http://en.wikipedia.org/wiki/Subtropical
Member Since: December 8, 2005 Posts: 0 Comments: 17
285. hurricane23
5:42 PM GMT on May 09, 2007
Everything iam looking at indicates continued weaken at maybe at a faster rate then indicated by the NHC.
Member Since: May 14, 2006 Posts: 8 Comments: 13804
284. lilmax
5:42 PM GMT on May 09, 2007
Andrea isn't very impressive for something with tropical storm force winds.
283. reeldrlaura
5:39 PM GMT on May 09, 2007
Posted By: thelmores at 5:17 PM GMT on May 09, 2007.
you know in life, alot of times when persuing "anything", its all about the chase!

now that we have a named storm..... ho-hum! :D

the chase the last couple days was fun..... now the STS hangover! LOL

AMEN, THEL!
Member Since: July 31, 2005 Posts: 93 Comments: 6007
282. dnalia
5:39 PM GMT on May 09, 2007
Bring on the rain!

I see a lot of people posting pictures/images but they aren't explaining them. Would it be too much to ask for an explanation with pics? It would help out us new people a lot.

Thanks
281. seflagamma
5:39 PM GMT on May 09, 2007
thelmore, thanks, I realized I said April so went back and corrected it! LOL!!!

I've been around for 2 years now just don't post as much as I use to and usually just lurk here and post every now and then.

But in "season" I check in everyday!!!!

soon all of the "season" folks will be returning.

Hi everyone!
Gams
Member Since: August 29, 2005 Posts: 299 Comments: 40916
280. hurricane23
5:28 PM GMT on May 09, 2007
Say bye to bye to andrea if this trend continues as convection is decreaseing and personally i think the NHC should have waited a tad longer but its to close to the coast so they had to take action.

Convection greatly decreasing
Member Since: May 14, 2006 Posts: 8 Comments: 13804
279. TheCaneWhisperer
5:25 PM GMT on May 09, 2007
If anything! It's a good indicator that the hostile conditions we had last year are not going to be present this year, if anyone was doubting an active season! Last year, this storm woulden't have even been a question.
278. thelmores
5:21 PM GMT on May 09, 2007
"Posted By: StormJunkie a
Wow, looks like western side is falling apart right now."

True, I think it's still "trying" to transition, and making an attempt (a weak one) to close off its COC........

of course, thats an untrained eye! LOL
Member Since: September 8, 2005 Posts: 0 Comments: 3805
277. SavannahStorm
5:21 PM GMT on May 09, 2007
Well, we finally got the first good, soaking shower here in Savannah. Too bad it didn't last long, but looks like there'll be more on the way.
Member Since: September 22, 2005 Posts: 18 Comments: 2343
276. thelmores
5:17 PM GMT on May 09, 2007
you know in life, alot of times when persuing "anything", its all about the chase!

now that we have a named storm..... ho-hum! :D

the chase the last couple days was fun..... now the STS hangover! LOL
Member Since: September 8, 2005 Posts: 0 Comments: 3805
275. thelmores
5:16 PM GMT on May 09, 2007
seflagamma, GOOD TO SEE YA! :)

oh, and BTW..... it's a MAY storm! LOL
Member Since: September 8, 2005 Posts: 0 Comments: 3805
274. Bamawatcher
5:15 PM GMT on May 09, 2007
Just curious I know it is early, way to early for a storm to come over from the eastern Atlantic, but are those storms from Africa starting to creep north a little???? And of course tomorrow they could start to creep to the south again.... Just wondering if there was any relevance in what I was looking at....
Member Since: August 28, 2006 Posts: 0 Comments: 46
273. seflagamma
5:13 PM GMT on May 09, 2007
NOOOOO it's not June yet!!!!!!!

LAST year we were suppose to have an April Storm but didn't and it was a very quite season; now this year we have a May storm and no one expected it...of course, we've been watching this for a week now so there was a small chance.......

thanks for the updates and I guess we have something to watch now.
Member Since: August 29, 2005 Posts: 299 Comments: 40916
272. turtlehurricane
5:09 PM GMT on May 09, 2007
I have posted my thoughts here, basically slow drifting and weakening.

Hurricane Warning
Member Since: July 22, 2005 Posts: 227 Comments: 469
271. reeldrlaura
5:06 PM GMT on May 09, 2007
NICE, steady soaking rain here in Atlantic Beach.....
Member Since: July 31, 2005 Posts: 93 Comments: 6007
270. dewfree
5:02 PM GMT on May 09, 2007
now why would this subtropical hybred storm be surpising to anyone that has been paying attention to it .it is just enough to get the name andrea used up he he but anyway a good thing to watch over the comming season cause your going to see more storms like this one just as you did last season but the origion is slightly different but the case is the same untill the NAO changes its ocillation these types of storms will develope and reek havic along the coast as far as errosion is concerned .watch these storms casue they will intereact with true nature tropical storms and see what happens as they influence the steering flow and you will know where to be of watchfull eye as foar as land fall . have a good one .
Dew
Member Since: August 27, 2006 Posts: 7 Comments: 589
269. StormJunkie
5:01 PM GMT on May 09, 2007
Wow, looks like western side is falling apart right now.
Member Since: August 17, 2005 Posts: 26 Comments: 16842
268. Skyepony (Mod)
4:55 PM GMT on May 09, 2007
I wonder why there was never a Supplementary Vortex Data Message
Member Since: August 10, 2005 Posts: 173 Comments: 38140
267. MTJax
4:55 PM GMT on May 09, 2007
A reconnaissance plane this morning found the low east of Jacksonville had a homogenous temperature profile -- in other words, little temp. change from one sector to the other -- indicating the system is now less baroclinic but still not purely tropical either. It's neither warm or cold core so the circulation has been upgraded to subtropical storm "Andrea" with a few areas of winds near 45 mph in some of the stronger thunderstorm bands mainly to the east & southeast of the center; there will be little change in strength before slow weakening begins by Thursday. A tropical storm WATCH has been posted for the First Coast BUT I'll go back to what I've harped on the last several days: THIS SYSTEM WHETHER TROPICAL, SUBTROPICAL, HYBRID OR COLD CORE WILL NOT HAVE EXTREME IMPACTS ON THE AREA:

-- high seas & surf with a high rip current risk through Thursday & some beach erosion

-- gusty but not damaging winds

-- periods of rain primarily along & east of Highway 301....especially I-95 corridor to the beaches

-- inland fires will continue to be fanned by gusty winds with little hope for much rain though there will be better thunderstorm chances Thu. afternoon through the weekend.

Published Wednesday, May 09, 2007 11:11 AM by mburesh
266. Skyepony (Mod)
4:52 PM GMT on May 09, 2007
Wed May 09 2007
1559 GMT
Latitude 31.8 N
Longitude 80.7 W
No turbulence
Currently flying in the clear
Flight altitude 1017 feet (310 meters)
Flight level winds 30 degrees at 45 knots (51 mph)
Temperature 18 C Dewpoint 16 C
Surface Pressure 1008 millibars
Surface winds 20 at 35 knots (40 mph)
Remarks: AF303 01AAA INVEST OB 17


Wed May 09 2007
1620 GMT
Latitude 31.8 N
Longitude 82.3 W
No turbulence
Currently flying in the clear
Flight altitude 20014 feet (6100 meters)
Flight level winds 30 degrees at 31 knots (35 mph)
Temperature -15 C Dewpoint -43 C
Remarks: AF303 01AAA INVEST OB 18

& they are headed home
Member Since: August 10, 2005 Posts: 173 Comments: 38140
265. swatkins
4:48 PM GMT on May 09, 2007
Posted By: pottery at 2:50 PM GMT on May 09, 2007.

"
The basic difference between smoke particles and dust ( in the context of an earlier question ) is that smoke ( by the fact that it is a column of hot air ) causes an isolated updraft, and it can exist even in moist air. Dust has no inherrant local updraft with it, and if it is in moist air it falls. So smoke can cause cloud, dust cant."

I could see that argument if the smoke was interacting very close to the source of the fire where there is great heat. In this case the fires are a long way away and the super warm air must have cooled greatly by the tine it is swept up into the circulation of the storm. That would leave us with mostly ash and very little heat.

The reason I bring this up is I was watching the storm firing heavier rain bands to the south south west of the center and sweep those to the east. I was wondering why they were forming in that location after the brush with the coast. I was wondering if they were being fired by the ash or if the increased heat coming off of the mainland was causing it...
264. Trouper415
4:47 PM GMT on May 09, 2007
Hello Andrea and the 2007 HURRICANE SEASON! WELCOME! I ask that you go easy on everyone again this year. Thanks!

Peace
Member Since: September 22, 2005 Posts: 5 Comments: 637
263. IKE
4:44 PM GMT on May 09, 2007
Latest GFS has Andrea eventually crossing into central Fl.Link
Member Since: June 9, 2005 Posts: 23 Comments: 37858
262. observer12
4:42 PM GMT on May 09, 2007
probably missed this discussion already, but any thoughts on what the wildlife smoke would do to a storm? obviously saharan dust is not so good for keeping a storm going. how about smoke?
261. Tazmanian
4:42 PM GMT on May 09, 2007
what i find rare is that we are seeing are 1st name storm be for the East Pacific dos that is so rare
Member Since: May 21, 2006 Posts: 5091 Comments: 115234
260. MahFL
4:35 PM GMT on May 09, 2007
WeatherByrd....have you heard of Google ?

Subtropical Storm defination
Member Since: June 9, 2004 Posts: 0 Comments: 3541
259. Bamatracker
4:32 PM GMT on May 09, 2007
sub-tropical shows characteristics of a warm-core and a cold-core system. Typically the highest winds are not right by the center of the rotation, but about 100 miles away from center. Tropical is a pure warm-core system and you know the rest.
Member Since: May 17, 2006 Posts: 6 Comments: 1367
258. WSI
4:31 PM GMT on May 09, 2007
257. IKE
4:31 PM GMT on May 09, 2007
Looking at a visible satellite...seems to be holding it's on. I don't see any weakening.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
256. cajunkid
4:28 PM GMT on May 09, 2007
national radar Link
Member Since: July 10, 2005 Posts: 3 Comments: 1279

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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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