Chris receives charity – 040500L update

August 4, 2006

About 3 hours ago, writing about what appeared to be a comeback for Chris:

Now it remains to see if this is Michael Jordan coming back to the Bulls…or Michael Jordan coming back to the Wizards.

At the moment the situation appears to be the latter… the comeback is over and Chris fell short of coming near his peak.

I was too hasty in posting the 0200 update. Waiting just a few more minutes to digest the recon data would have saved me quite a bit of embarassment.

Here’s what went wrong… First, a look at the observation, which when combined with my thinking that Chris was improving (per satellite imagery) led me astray:

SXXX50 KNHC 040553
AF307 0703A CHRIS        HDOB 12 KNHC
0541. 2058N 06948W 01526 0078 134 026 192 112 026 01640 0000000000
0542  2057N 06949W 01522 0075 129 024 190 118 025 01633 0000000000
0542. 2056N 06951W 01519 0073 095 022 172 130 025 01627 0000000000
0543  2055N 06952W 01532 0076 110 020 168 150 022 01644 0000000000
0543. 2053N 06953W 01517 0074 103 022 188 146 023 01627 0000000000
0544  2052N 06954W 01529 0076 101 017 186 122 020 01640 0000000000
0544. 2050N 06954W 01524 0075 126 016 196 112 021 01635 0000000000
0545  2049N 06955W 01523 0074 130 018 170 122 024 01633 0000000000
0545. 2047N 06956W 01520 0075 099 026 170 130 027 01631 0000000000
0546  2046N 06957W 01508 0077 118 047 122 122 053 01620 0000000000
0546. 2045N 06959W 01561 0088 127 013 134 134 023 01684 0000000000
0547  2044N 07000W 01516 0087 171 012 164 164 012 01639 0000000000
0547. 2043N 07001W 01525 0085 170 011 170 170 011 01646 0000000000
0548  2043N 07003W 01525 0084 173 011 172 172 011 01645 0000000000
0548. 2042N 07005W 01524 0083 171 010 176 170 010 01643 0000000000
0549  2042N 07006W 01525 0083 179 008 176 174 008 01643 0000000000
0549. 2042N 07008W 01528 0084 195 007 176 176 009 01647 0000000000
0550  2042N 07010W 01528 0082 190 008 176 176 010 01646 0000000000
0550. 2042N 07012W 01516 0081 185 009 180 180 010 01632 0000000000
0551  2043N 07013W 01509 0079 188 008 176 176 009 01623 0000000000
This is a set of observations collected by the hurricane hunter at 30 second intervals.  The italicized observation is the one in question, bold-faced are the 30 second and peak 10 second wind-averages from the observation. The discontinuity created by that observation (i.e the lack of observations in the 30-50 knot range) should have raised a flag right off the bat. But, I rationalized it away.

Had I waited a few minutes before posting I would have seen the pressure that was recorded in the center of the storm, 1012 millibars, which was unchanged from the observation in the early evening.  A bump upward in the overall winds without a drop in pressure is unlikely.

After seeing that, I edited the post to throw in the cautionary note.  Indeed, the observation did prove to be extremely unrepresentative.  The highest flight level wind recorded since then was a mere 29 knots, which is well below tropical storm strength.

The other thing I noticed during between 2 and 3 AM was that the upper level low that sheared the convection completely off of Chris last night was beggining to take a similar toll tonight.

Because of the low wind speeds observed and the shearing going on, Chris’ continued classification as a tropical storm is quite charitable. Continuity is the only reason to do so, and that’s essentially what the 5 AM discussion says (“Even though these winds to not currently support a tropical storm… convection is still present and close to the center… so the prudent course of action is to maintain an initial intensity of 35 knots”).

I think the forecaster is giving Chris three hours of time to improve (recon will complete their mission at 8 AM) and if it doesn’t it could be downgraded to a tropical depression at that time, or if the forecaster is extremely cautious, do so at 11 AM if satellite imagery doesn’t show improvement.  That possibility is mentioned in the forecast discussion and seems very likely to me at this time.

Chris may have fatally lost the race against the upper level low.  (Many thanks to Brendan Loy for pointing that post out… it put a big smile on my face (something I’ve been lacking lately) and on top of that it was good meteorology, not just silly humor).

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