ATL GUSTAV: Tropical Depression - Discussion

[cpdaman]

almost looks like the east side is under the influence of the trough (to the NNE) while the s. west side the ridge

[KWT]

The visible is impressive but the IR is not very impressive as of yet. We will see if it can improve.

Well this is still ramping up at the moment, also whilst there is a closed eyewall I'm betting its not very strong at this stage but is clearly ramping up pretty readily IMO...think we will see a fairly classic eye burst out in the next 9-12hrs.

[KWT]

I believe this equation applies with Gustav:

The stronger the storm gets = The quicker it will turn north.

I have not been able to follow this storm much, so please tell me if I am wrong.

Well actually according to the BAM guidence at least right now a stronger system would actually end up further south than a weaker system...

[Stormcenter]

Well cpdaman the intial motion is estimated at 310...but a stronger storm would actually bend back westward faster based on the current steering.

I thought it was the other way around.

[hial2]

I believe this equation applies with Gustav:

The stronger the storm gets = The quicker it will turn north.

I have not been able to follow this storm much, so please tell me if I am wrong.

Not necessarily. Depends on the strenght of the high pressure...remember Andrew's beeline?

[TampaFl]

From NWS Tampa AFD: (Of course timimg is crucial - interesting about the trough this weekend - this was put out just before Gustav was named)

FXUS62 KTBW 251707
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
110 PM EDT MON AUG 25 2008

.SHORT TERM (TONIGHT-WEDNESDAY)...SOUTHWESTERLY FLOW IS GRADUALLY
SWITCHING TO THE SOUTH AND BECOMING LIGHT AS PRESSURE GRADIENTS OVER
THE REGION ARE RELAXING. SURFACE RIDGE OVER THE WESTERN ATLANTIC
SLOWLY EXPANDING WESTWARD AND INTO THE FLORIDA AND EASTERN GULF
THROUGH WEDNESDAY. MODELS ARE IN FAIR AGREEMENT IN BUILDING HIGH
PRESSURE ALOFT WITH SUBSIDENCE AND LIGHT WINDS PREVAILING ON TUESDAY
AND WEDNESDAY. HOWEVER...ENOUGH LOW LEVEL MOISTURE REMAINS OVER THE
AREA IN THE WAKE OF FAY ALONG WITH AFTERNOON SEA BREEZES
CIRCULATIONS DEVELOPING THROUGH THE PERIOD WHICH WILL BRING BACK
CONVECTION NEAR THE COAST IN THE LATE MORNING AND EARLY
AFTERNOON...THEN PUSHING INLAND IN THE LATE AFTERNOON AND EARLY
EVENING HOURS.

POPS ARE BACK DOWN TO CLIMO VALUES TO AROUND 30 AND 40 PERCENT IN
THE AFTERNOON PERIODS...AND ISOLATED 20 PERCENT FOR THE EVENINGS.
WITH DEW POINTS STILL RUNNING AROUND THE MID 70S AND TEMPERATURES
CLIMBING BACK TO THE LOWER 90S IT WILL BE POSSIBLE TO EXPERIENCE
AFTERNOON PERIODS WITH HEAT INDEX VALUES AROUND 100. MORNING
LOWS WILL REMAIN CLOSE TO OR AT NORMALS.

&&

.LONG TERM (WEDNESDAY NIGHT - MONDAY)...SFC RIDGE AXIS WILL CONTINUE
OVER THE PENINSULA DURING THE MIDDLE OF THE WEEK WITH TYPICAL
DIURNAL TSTMS EXPECTED. UPPER TROF WILL DEVELOP OVER THE SOUTHEAST
STATES BY LATE IN THE WEEK AND OVER THE WEEKEND...THUS CONTINUING...
IF NOT ENHANCING THE RISK FOR AFTERNOON AND EVENING TSTMS OVER THE
AREA. OTHERWISE...KEEPING A CLOSE WATCH ON 94L...STAY TUNED!&&

.AVIATION...SCATTERED TSTMS WITH BRIEF PERIODS OF MVFR OR IFR
CONDITIONS WILL AFFECT THE TERMINALS THIS AFTERNOON AND THEN MOVE
INLAND. VFR CONDITIONS CAN BE EXPECTED OUTSIDE OF THIS ACTIVITY AND
MOST OF OUR CWA TONIGHT. SIMILAR SCENARIO ON TUESDAY.

&&

.MARINE...WINDS AND SEAS EXPECTED TO REMAIN BELOW HIGHLIGHT CRITERIA
THROUGH THE WORK WEEK...EXCEPT IN THE VICINITY OF THUNDERSTORMS
WHICH WILL BRING BRIEF PERIODS OF ROUGH SEAS...GUSTY WINDS AND
DEADLY CLOUD TO WATER LIGHTNING.

&&

.FIRE WEATHER...DRIER AIR WILL FILTER OVER THE AREA BY THE END OF
THE WORK WEEK BUT RELATIVE HUMIDITIES SHOULD REMAIN ABOVE CRITICAL
LEVELS WITH NO FIRE WEATHER CONCERNS ANTICIPATED.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA 77 90 79 90 / 10 30 20 30
FMY 77 92 79 91 / 20 40 20 40
GIF 75 92 76 93 / 20 40 20 40
SRQ 77 90 78 89 / 10 30 20 30
BKV 74 90 75 91 / 20 30 20 30
SPG 79 89 80 89 / 10 30 20 30

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&

$$

SHORT TERM/MARINE...AR
LONG TERM/AVIATION...EJ

[Steve]

>>Should be a interesting few days ahead!

No *#$(. I'm going to Chicago on Wednesday to visit the future 2nd better half, but (un)fortunately I'll be back on Thursday around noon. I doubt I'll do much tropical tracking and am hoping not to come home to a contraflow. Think it will still be a bit early in 72 hours, but you never know.

Steve

[Steve]

>>I thought it was the other way around.

It is, generally. But there aren't hard rules in the tropics unless you understand 3D fluid dynamics (adding in temperature and other variables) which no one really does - or even if they do - we don't have all the data to say for certain any one thing is for sure. Tropical systems continue to prove that while they will often follow general rules of thumb to a point, don't bet the house on it.

Steve

[Ed Mahmoud]

GFS days 5 to 7 seems to show 500 mb heights in such a way Northern or Northeastern GOMEX would be the target.

[ColdFusion]

Being just days away from the 3rd Anniversary of Katrina, would be ugly to have a storm threatening the Gulf.

[storms in NC]

I am glad that the east coast is safe again this year. That is from Ga up. But we sure could use the heavy rains

uhhhhhhhhhhhhhh....... Have you looked at a calendar?

Yeppers sure have. Aug 25 th and nothing in any way in the works. We have had a few not many after around the 20th of Sept. And to get a CV Storm would have to have one in the works and there is not. Plus we have the ridge over us and have had for the last few years. The last one to come here (Wilm, cape fear river) was Floyd. And there has been only 2-3 storms after Floyd up around Morehead City.
Now we might get a home maker but not a Cv storm

[ROCK]

GFS days 5 to 7 seems to show 500 mb heights in such a way Northern or Northeastern GOMEX would be the target.

yeah but that depends how far west it actually emerges in the GOM now doesnt it Edward.

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... =Animation

[gtsmith]

To: anyone who wants to answer.

Question: there's a lot of talk on here about how the synoptics will impact this storm (or any storm for sake of argument). Is the reverse not true? Does the storm not impact the synoptics? As an example, would a ridge not build in due to the storm, acting like a bulldog with a head of steam, prevent said ridge from building in?

Just curious and looking to learn...thx in advance, and please no flaming

[Ed Mahmoud]

GFS days 5 to 7 seems to show 500 mb heights in such a way Northern or Northeastern GOMEX would be the target.

yeah but that depends how far west it actually emerges in the GOM now doesnt it Edward.

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... =Animation

I sneeze on the Canadian.

[cpdaman]

I am glad that the east coast is safe again this year. That is from Ga up. But we sure could use the heavy rains

uhhhhhhhhhhhhhh....... Have you looked at a calendar?

Yeppers sure have. Aug 25 th and nothing in any way in the works. We have had a few not many after around the 20th of Sept. And to get a CV Storm would have to have one in the works and there is not. Plus we have the ridge over us and have had for the last few years. The last one to come here (Wilm, cape fear river) was Floyd. And there has been only 2-3 storms after Floyd up around Morehead City.
Now we might get a home maker but not a Cv storm

wishful thinking

[HURAKAN]

25/1745 UTC 15.9N 70.5W T3.5/3.5 07L -- Atlantic Ocean

[Steve]

>>Being just days away from the 3rd Anniverary of Katrina, would be ugly to have a storm threatening the Gulf.

When I was a kid, it seems like there were at least a few Labor Day weekends with a real threat on the map. Maybe it's just faulty memory though.

>>Now we might get a home maker but not a Cv storm

Wouldn't automatically assume that at this point. It's August 25th, and we're up to the "G" storm. In some years, the season is over or this is one of the last letters used. We're still > 2 weeks to the peak of the season. You might be right, but you might not, obviously.

Steve

[ROCK]

GFS days 5 to 7 seems to show 500 mb heights in such a way Northern or Northeastern GOMEX would be the target.

yeah but that depends how far west it actually emerges in the GOM now doesnt it Edward.

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... =Animation

I sneeze on the Canadian.

You dont want to know what I do to the EURO......

[Stormcenter]

GFS days 5 to 7 seems to show 500 mb heights in such a way Northern or Northeastern GOMEX would be the target.

Will Gustav still be in the vicinity then? It's pretty far
west already. As someone else posted "timing is everything".

[Regit]

I am glad that the east coast is safe again this year. That is from Ga up. But we sure could use the heavy rains

uhhhhhhhhhhhhhh....... Have you looked at a calendar?

Yeppers sure have. Aug 25 th and nothing in any way in the works. We have had a few not many after around the 20th of Sept. And to get a CV Storm would have to have one in the works and there is not. Plus we have the ridge over us and have had for the last few years. The last one to come here (Wilm, cape fear river) was Floyd. And there has been only 2-3 storms after Floyd up around Morehead City.
Now we might get a home maker but not a Cv storm

It does not take 25 days to get one from Africa to NC.

And there's no magic 9/20 rule. Hugo hit on 9/21. Hazel hit in mid-October.