ATL: IRENE - Remnants - Discussion

[Dave]

DECODED DROPSONDE

Code: Select all

Product: Air Force Temp Drop (Dropsonde) Message (UZNT13 KNHC)
Transmitted: 23rd day of the month at 16:05Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 302)
Storm Number: 09
Storm Name: Irene (flight in the North Atlantic basin)
Mission Number: 8
Observation Number: 12

Part A...


Date: Near the closest hour of 16Z on the 23rd day of the month
Highest Mandatory Level For Which Wind Was Reported: 700mb
Coordinates: 20.6N 71.1W
Location: 60 miles (96 km) to the S (178°) from Cockburn Town, Turks and Caicos Islands (GBR).
Marsden Square: 080 (About)

Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed
978mb (28.88 inHg) Sea Level (Surface) 27.2°C (81.0°F) 25.3°C (77.5°F) 160° (from the SSE) 9 knots (10 mph)
1000mb -196m (-643 ft) Other data not available.
925mb 495m (1,624 ft) 24.2°C (75.6°F) 23.1°C (73.6°F) 185° (from the S) 11 knots (13 mph)
850mb 1,236m (4,055 ft) 21.0°C (69.8°F) 19.7°C (67.5°F) 190° (from the S) 3 knots (3 mph)
700mb 2,911m (9,551 ft) 16.4°C (61.5°F) Approximately 11°C (52°F) 20° (from the NNE) 7 knots (8 mph)

Information About Radiosonde:
- Launch Time: 15:56Z
- About Sonde: A descending radiosonde tracked automatically by satellite navigation with no solar or infrared correction.

Remarks Section...


Dropsonde Location: Dropped in eye.

Splash Location: 20.58N 71.1W
Splash Time: 15:59Z

Release Location: 20.58N 71.1W View map)
Release Time: 15:56:03Z

Splash Location: 20.58N 71.1W (
Splash Time: 15:59:10Z

Mean Boundary Level Wind (mean wind in the lowest 500 geopotential meters of the sounding):
- Wind Direction: 175° (from the S)
- Wind Speed: 9 knots (10 mph)

Deep Layer Mean Wind (average wind over the depth of the sounding):
- Wind Direction: 155° (from the SSE)
- Wind Speed: 2 knots (2 mph)
- Depth of Sounding: From 692mb to 977mb

Average Wind Over Lowest Available 150 geopotential meters (gpm) of the sounding:
- Lowest 150m: 158 gpm - 8 gpm (518 geo. feet - 26 geo. feet)
- Wind Direction: 165° (from the SSE)
- Wind Speed: 9 knots (10 mph)

Sounding Software Version: AEV 20802


Part B: Data For Significant Levels...


Significant Temperature And Relative Humidity Levels...
Level Air Temperature Dew Point
978mb (Surface) 27.2°C (81.0°F) 25.3°C (77.5°F)
850mb 21.0°C (69.8°F) 19.7°C (67.5°F)
810mb 19.0°C (66.2°F) 17.9°C (64.2°F)
750mb 19.8°C (67.6°F) Approximately 13°C (55°F)
706mb 17.4°C (63.3°F) Approximately 11°C (52°F)
692mb 15.0°C (59.0°F) Approximately 10°C (50°F)

Significant Wind Levels...
Level Wind Direction Wind Speed
978mb (Surface) 160° (from the SSE) 9 knots (10 mph)
915mb 190° (from the S) 12 knots (14 mph)
850mb 190° (from the S) 3 knots (3 mph)
692mb 25° (from the NNE) 8 knots (9 mph)


---



[Battlebrick]

Remember, they are fixing at 700 mb so the pressure is always going to be lower than the actual surface pressure.

[KWT]

Dropsonde says 978 mb.. down 2mb, strengthening?

Looks like they got the eastern section of the western eyewall not quite the center, so pressure maybe a little lower around 975-976mbs.

[Aric Dunn]

Latest pass got about 975mbs, so its probably starting to strengthening, lowest pressure looks like it wass right in the weaker cloud cover, suggesting that is indeed the true eye.

They seemed to have missed the center a tad.. winds were still over 10kts

[crimi481]

More shear than Models forecast
Weaker system (at this time) than forecast
More interaction from D.R. mountains than forecast (keep it weaker -go more with low leel flow)

A clear trek to the west seen here
http://www.ssd.noaa.gov/goes/flt/t2/flash-bd.html

[SouthFLTropics]

If the more west motion continues for an extended period of time I would think that Cuba will have to at least put up a TS Warning for the NE Cuban coastline. I'm suprised they haven't already considering the proximity of Irene to them.

SFT

[KWT]

Lets remember guys that Irene is still much stronger at this point then we were expecting a few days ago, it'd never have been a cat-2 if it trekked over Hispaniola.

[artist]

000
URNT15 KNHC 231609
AF302 0809A IRENE HDOB 20 20110823
155900 2036N 07103W 6915 03006 9762 +134 +106 140012 013 028 000 00
155930 2036N 07103W 6915 03006 9764 +133 +115 171019 023 030 000 00
160000 2036N 07100W 6915 03017 9784 +121 //// 171028 030 041 002 01
160030 2036N 07058W 6913 03024 9795 +120 +115 161037 044 047 000 00
160100 2036N 07056W 6908 03043 9806 +118 +101 166053 055 052 001 03
160130 2036N 07054W 6912 03045 9813 +121 +101 176059 060 058 001 00
160200 2036N 07052W 6917 03051 9827 +119 +099 181067 069 063 004 03
160230 2036N 07051W 6914 03064 9843 +114 +102 181065 069 064 005 00
160300 2036N 07049W 6920 03066 9864 +102 //// 176059 060 060 014 05
160330 2036N 07047W 6921 03074 //// +084 //// 172060 062 056 028 05
160400 2036N 07045W 6916 03086 //// +081 //// 175061 062 060 018 01
160430 2036N 07043W 6911 03099 //// +080 //// 176059 060 061 013 01
160500 2035N 07042W 6915 03101 //// +080 //// 179061 061 061 012 01
160530 2035N 07040W 6916 03108 //// +082 //// 177059 063 059 010 01
160600 2035N 07038W 6910 03121 9920 +099 //// 177058 060 057 006 01
160630 2035N 07036W 6918 03118 //// +091 //// 178059 060 057 006 01
160700 2035N 07034W 6912 03128 //// +087 //// 177059 060 057 006 01
160730 2035N 07033W 6916 03131 //// +089 //// 178058 059 058 011 01
160800 2035N 07031W 6911 03135 //// +080 //// 185062 064 057 013 01
160830 2035N 07029W 6916 03135 //// +077 //// 184055 058 057 010 01
$$
;

[dixiebreeze]

More shear than Models forecast
Weaker system (at this time) than forecast
More interaction from D.R. mountains than forecast (keep it weaker -go more with low leel flow)

A clear trek to the west seen here
http://www.ssd.noaa.gov/goes/flt/t2/flash-bd.html

Surely is looking west on that Dvorak IR!

[Sanibel]

The weak trough is plunging enough to pull Irene up. Right now the ridge is keeping it from plunging too hard but the trough will win that battle and pull Irene North. The High is strong enough to pinch a cut-off lobe in the SW of the trough.


The reason Irene isn't moving fast is because it is under a weak High. We saw weak steering currents in this area with Emily:


http://www.ssd.noaa.gov/goes/east/eaus/flash-wv.html



.

[WxGuy1]

Remember, they are fixing at 700 mb so the pressure is always going to be lower than the actual surface pressure.

Eh? If they're fixing / flying at 700 mb, the pressure immediately outside the plane is 700 mb. The pressure values reported in this thread (974.4, 978, 980, etc) are sea-level pressures.

[dixiebreeze]

23/1145 UTC 20.5N 70.5W T4.5/4.5 IRENE -- Atlantic

[KWT]

Looks to me like its moving around 280 degrees at the moment...

[Dave]

[Evil Jeremy]

Just like Emily... when will it make the turn...

[deltadog03]

I think the models are not seeing how slow this joker is moving.....timing is EVERYTHING

[mutley]

im really beginning to wonder if this ridge dropping south over NC/SC is going to have an affect.. because look at the flow of the complex of thunderstorms heading towards florida. should be going the other direction.

I saw that awhile ago, and was wondering about the direction of those storms too.

[Battlebrick]

Remember, they are fixing at 700 mb so the pressure is always going to be lower than the actual surface pressure.

Eh? If they're fixing / flying at 700 mb, the pressure immediately outside the plane is 700 mb. The pressure values reported in this thread (974.4, 978, 980, etc) are sea-level pressures.

Yesterday, when they were fixing at 700 mb, the "surface" pressure they were getting from the plane was always lower than the dropsonde surface pressure.. why?

[RL3AO]

I think the models are not seeing how slow this joker is moving.....timing is EVERYTHING

Slow mover = more east?

Or doesnt it give it more time for a ridge to start building in again?

[Evil Jeremy]

I think the models are not seeing how slow this joker is moving.....timing is EVERYTHING

Does slower mean more east or west?