99L Recon Discussion Thread

[MWatkins]

If that 1002.7 pressure is valid...and there is a center down there...the system is doomed anyway. There is nothing around 10.8 57.5 to maintain the system...the significant weather is well to the north and west of there.

MW

[wxman57]

Plane is reporting calm surface winds over a large area near 11N/58W with pressures 1010mb. Don't think there was a 1002.7mb pressure observed. Wasn't reported in regular recon reports, anyway. Lowest I've seen is 1009mb near Barbados. No westerly surface winds reported yet, either. Looks like a moderate wave to me. But forecasting what the NHC will do is harder than forecasting hurricanes by far.

There was one W report... only one missing is NW I believe.

Haven't seen a west surface wind reported. Which observation was it? I've been on a plane flying back from New Orleans over the last few hours and only had my BlackBerry to look at. I'm in the office now.

[KWT]

I believe this was the one, not quite exactly due west but close:

174330 1139N 05808W 9771 00289 0100 +220 +220 265005 006 025 016 00

[SouthFloridawx]

Could you post the most significant winds and pressures on that graphic?

[Chris_in_Tampa]

That is a screenshot from the output of my decoder. I'll write over the screenshot next time.

Here is where the lowest pressure was measured:

[CrazyC83]

We now have winds from due north.

[wxman57]

We now have winds from due north.

Recon reports the north wind at 15kts as "convection induced"

[Downdraft]

can someone send me a pm on how to post a pic or graphic on the board? thanks.

[StormScanWx]

When will the next recon mission to investigate be after the current ongoing one?

[RL3AO]

When will the next recon mission to investigate be after the current ongoing one?

12 hour fixes I think.

[Brent]

Looks like tomorrow at Noon:

I. ATLANTIC REQUIREMENTS
1. SUSPECT AREA (CARIBBEAN)
FLIGHT ONE
A. 02/1600Z
B. AFXXX 02DDA INVEST
C. 02/1400Z
D. 14.0N 65.5W
E. 02/1500Z TO 02/2000Z
F. SFC TO 10,000 FT
2. SUCCEEDING DAY DAY OUTLOOK: BEGIN 12-HRLY FIXES
AT 03/1200Z IF SYSTEM DEVELOPS.
3. REMARKS: THIS MISSION ORIGINALLY SCHEDULED FOR 02/1200Z
HAS BEEN SLIPPED TO 02/1600Z.

[Chris_in_Tampa]

Well I thought my decoder broke. Must have been the plane with the error. Reported an extraploated surface pressure of 987.5 mb.

[WindRunner]

Looks like tomorrow at Noon:

I. ATLANTIC REQUIREMENTS
1. SUSPECT AREA (CARIBBEAN)
FLIGHT ONE
A. 02/1600Z
B. AFXXX 02DDA INVEST
C. 02/1400Z
D. 14.0N 65.5W
E. 02/1500Z TO 02/2000Z
F. SFC TO 10,000 FT
2. SUCCEEDING DAY DAY OUTLOOK: BEGIN 12-HRLY FIXES
AT 03/1200Z IF SYSTEM DEVELOPS.
3. REMARKS: THIS MISSION ORIGINALLY SCHEDULED FOR 02/1200Z
HAS BEEN SLIPPED TO 02/1600Z.

Flight should have first fix at noon . . . section A is the first fix time, with section C being the takeoff time and E being the on-site (in storm) time . . .

[WindRunner]

Also, if I may, the recon never "observed" any pressures . . . with the new HDOBs, the pressure group is extrapolated . . . hence when the geopotential heights fly up or down, the extrapolation varies wildly. There is no large area of 1020-something pressure, or a 1031 high on the south side of the storm . . . and there is no 1002 part of the storm either. The reccos seemed reasonably accurate . . . with lowest pressure reported there being 1006mb.

Personally, I'd put it at 1007mb right now, from the data I saw earlier. Was watching it in the office, and that was the lowest it got while in the convection (I believe the 1002.7 reading was near one of the corners).


Oh, and sorry I haven't been doing graphics. Since they're using the new (and computer-friendly) format, I think a GE plotter will be much easier to write. It probably won't be ready for tomorrow's mission, but I'll work on it some tonight and see what happens . . .

[Chris_in_Tampa]

I didn't realize the extrapolations could be so off sometimes. I'll have to remember that.

[WindRunner]

I didn't realize the extrapolations could be so off sometimes. I'll have to remember that.

When they are done by actual people, they are usually quite accurate . . . i.e. vortex fixes and the recco obs. The hdob sets are automated by computer . . . which probably grabs the geopotential group and the plane's pressure (the pressure level that the plane is flying at) and makes a guess. Hence, when the reported geopotential level rises without the plane's pressure rising, the extrapolated pressure will rise as well. You'll note that the geopotential at the 1030 extrapolations had geopotential level reports of just over 400m . . . for a 977mb level in the tropics, that'd be quite high, and therefore the plane thinks it's a good bit higher up and therefore inflates the surface pressure to a level that is actually beneath sea level.

[SouthFloridawx]

Bump...

[CrazyC83]

It should leave in a little over an hour? or does it arrive at the system then?

[Aquawind]

Ohh Goodie... FACTS.... Well the best we can get...

[Ivanhater]

take off!!...dont get your hopes up...I doubt they find anything..but its trying