CAT 5 Hurricane Dean - Archived threads

[x-y-no]

Can someone please explain why the guidance is more uncertain today than yesterday. I'm new, and don't understand why this is.

It's a question of how fast and how far the mid/upper level low now over Florida backs off to the west as the trough lifts out and ridging builds in.

Starting yesterday, several of the models (principally the GFDL) began to suggest that the low stalls in the Gulf.

[MSRobi911]

Good to hear from ya'll. Glad you did well. Will continue prayers for those in St. Luica and the other islands.

Mary

[Chris_in_Tampa]

URNT15 KNHC 171611
AF304 0404A DEAN HDOB 42 20070817
160400 1451N 06243W 6960 02993 9990 +071 +999 145099 100 081 050 01
160430 1451N 06243W 6960 02993 9904 +072 +072 143098 099 079 030 01
160500 1453N 06241W 6976 03011 9923 +076 +076 143097 098 070 019 00
160530 1454N 06239W 6980 03021 9944 +072 +072 140093 098 068 019 00
160600 1456N 06238W 6977 03042 9973 +064 +064 138089 089 064 019 00
160630 1457N 06237W 6969 03059 9971 +073 +073 141088 088 062 024 03
160700 1458N 06236W 6974 03063 9972 +079 +079 140088 088 062 043 03
160730 1459N 06235W 6971 03075 9990 +077 +077 143085 086 058 009 00
160800 1500N 06233W 6978 03075 9993 +081 +081 140079 081 057 047 03
160830 1500N 06233W 6978 03075 9998 +078 +078 141078 079 057 047 03
160900 1503N 06231W 6975 03092 0004 +077 +077 142076 078 057 020 00
160930 1503N 06231W 6975 03092 0002 +080 +080 142076 078 057 020 00
161000 1505N 06228W 6979 03096 0039 +066 +066 143071 073 056 041 03
161030 1507N 06227W 6968 03118 0060 +055 +055 140073 075 053 052 03
161100 1508N 06226W 6971 03114 0043 +069 +069 139071 072 050 011 03
161130 1509N 06224W 6983 03101 0045 +070 +070 139069 070 053 044 03
161200 1510N 06223W 6968 03125 0032 +081 +081 140070 071 053 041 03
161230 1511N 06222W 6975 03121 0037 +080 +080 141070 071 999 999 03
161300 1513N 06221W 6976 03123 0052 +072 +072 140070 071 999 999 03
161330 1514N 06219W 6969 03133 0058 +070 +070 140069 070 050 043 03

Product: Air Force High Density (HDOB) Message (URNT15 KNHC)
Transmitted: 17th day of the month at 16:11Z
Date: August 17, 2007
Aircraft: Air Force Aircraft (Last digit of aircraft registration number is 304)
Storm Number: 04
Storm Name: Dean (in the North Atlantic basin)
Mission Number: 4
Observation Number: 42
Time (Z) / Coordinates / Acft. Static Air Press. / Acft. Geo. Hgt. / Extrap. Sfc. Press. / Flt. Lvl. Wind (30s) / Peak (10s) Flt. Lvl. Wind / SFMR Peak (10s) Sfc. Wind / SFMR Rain Rate
16:04:00 14.85N 62.72W 696.0 mb 2,993 m - From 145° (SE) at 99 kts (113.8 mph) 100 kts (~ 115.0 mph) 81 kts 50 mm/hr
16:04:30 14.85N 62.72W 696.0 mb 2,993 m 990.4 mb From 143° (SE) at 98 kts (112.7 mph) 99 kts (~ 113.8 mph) 79 kts 30 mm/hr
16:05:00 14.88N 62.68W 697.6 mb 3,011 m 992.3 mb From 143° (SE) at 97 kts (111.5 mph) 98 kts (~ 112.7 mph) 70 kts 19 mm/hr
16:05:30 14.90N 62.65W 698.0 mb 3,021 m 994.4 mb From 140° (SE) at 93 kts (106.9 mph) 98 kts (~ 112.7 mph) 68 kts 19 mm/hr
16:06:00 14.93N 62.63W 697.7 mb 3,042 m 997.3 mb From 138° (SE) at 89 kts (102.3 mph) 89 kts (~ 102.3 mph) 64 kts 19 mm/hr
16:06:30 14.95N 62.62W 696.9 mb 3,059 m 997.1 mb From 141° (SE) at 88 kts (101.2 mph) 88 kts (~ 101.2 mph) 62 kts* 24 mm/hr*
16:07:00 14.97N 62.60W 697.4 mb 3,063 m 997.2 mb From 140° (SE) at 88 kts (101.2 mph) 88 kts (~ 101.2 mph) 62 kts* 43 mm/hr*
16:07:30 14.98N 62.58W 697.1 mb 3,075 m - From 143° (SE) at 85 kts (97.7 mph) 86 kts (~ 98.9 mph) 58 kts 9 mm/hr
16:08:00 15.00N 62.55W 697.8 mb 3,075 m 999.3 mb From 140° (SE) at 79 kts (90.8 mph) 81 kts (~ 93.1 mph) 57 kts* 47 mm/hr*
16:08:30 15.00N 62.55W 697.8 mb 3,075 m 999.8 mb From 141° (SE) at 78 kts (89.7 mph) 79 kts (~ 90.8 mph) 57 kts* 47 mm/hr*
16:09:00 15.05N 62.52W 697.5 mb 3,092 m 1000.4 mb From 142° (SE) at 76 kts (87.4 mph) 78 kts (~ 89.7 mph) 57 kts 20 mm/hr
16:09:30 15.05N 62.52W 697.5 mb 3,092 m 1000.2 mb From 142° (SE) at 76 kts (87.4 mph) 78 kts (~ 89.7 mph) 57 kts 20 mm/hr
16:10:00 15.08N 62.47W 697.9 mb 3,096 m 1003.9 mb From 143° (SE) at 71 kts (81.6 mph) 73 kts (~ 83.9 mph) 56 kts* 41 mm/hr*
16:10:30 15.12N 62.45W 696.8 mb 3,118 m 1006.0 mb From 140° (SE) at 73 kts (83.9 mph) 75 kts (~ 86.2 mph) 53 kts* 52 mm/hr*
16:11:00 15.13N 62.43W 697.1 mb 3,114 m 1004.3 mb From 139° (SE) at 71 kts (81.6 mph) 72 kts (~ 82.8 mph) 50 kts* 11 mm/hr*
16:11:30 15.15N 62.40W 698.3 mb 3,101 m 1004.5 mb From 139° (SE) at 69 kts (79.3 mph) 70 kts (~ 80.5 mph) 53 kts* 44 mm/hr*
16:12:00 15.17N 62.38W 696.8 mb 3,125 m 1003.2 mb From 140° (SE) at 70 kts (80.5 mph) 71 kts (~ 81.6 mph) 53 kts* 41 mm/hr*
16:12:30 15.18N 62.37W 697.5 mb 3,121 m 1003.7 mb From 141° (SE) at 70 kts (80.5 mph) 71 kts (~ 81.6 mph) - -
16:13:00 15.22N 62.35W 697.6 mb 3,123 m 1005.2 mb From 140° (SE) at 70 kts (80.5 mph) 71 kts (~ 81.6 mph) - -
16:13:30 15.23N 62.32W 696.9 mb 3,133 m 1005.8 mb From 140° (SE) at 69 kts (79.3 mph) 70 kts (~ 80.5 mph) 50 kts* 43 mm/hr*
At 16:04:00Z (first observation), the observation was 94 miles (151 km) to the WSW (251°) from Roseau, Dominica.
At 16:13:30Z (last observation), the observation was 62 miles (100 km) to the W (266°) from Roseau, Dominica.

Map this message:
http://www.tropicalatlantic.com/recon/p ... .35c-62.32

Suspect values are noted by an asterisk (*).

[Brent]

Other models trend north while gfs stubbornly keeps west.Time will tell

Yeah, and considering I trust the GFDL much more than the GFS, I am still feeling uneasy.

Come on now the GFDL has flopped in the past so it's not perfect.
I'm not saying the GFS track is written in stone nor do I think Dean will
follow its track but I do believe it will sees something the other model
trending north are missing. As we keep on saying time will tell. Hey by the way is that
Dean's sister in the Atlantic on this run?

Maybe Dean's brother...

[Steve]

>>Can someone please explain why the guidance is more uncertain today than yesterday. I'm new, and don't understand why this is.

Differences in the models. If you don't understand, the best thing to do is read the "Discussions" at the National Hurricane Center. They explain (usually) where the divergence or the lack of confidence comes from (in this case, the latter part of the model runs, or 4-5 days out). The more of those discussions you read, the more you will learn about what they are thinking. Unfortunately, their best writer, Stacey Stewart, isn't doing them this year. He had a way of explaining the NHC's thinking better than anyone.

Steve

[tracyswfla]

So are we still thinking that the SW Coast of Florida is out of the woods???

[Extremeweatherguy]

126 hrs.. http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_126l.gif

[Brent]

Looks south of the 6z... definitely Mexico.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_126l.gif

Weakness is still there!

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_126l.gif

[Extremeweatherguy]

Other models trend north while gfs stubbornly keeps west.Time will tell

Yeah, and considering I trust the GFDL much more than the GFS, I am still feeling uneasy.

Come on now the GFDL has flopped in the past so it's not perfect.
I'm not saying the GFS track is written in stone nor do I think Dean will
follow its track but I do believe it will sees something the other model
trending north are missing. As we keep on saying time will tell. Hey by the way is that
Dean's brother in the Atlantic on this run?

The GFS was one of the furthest south models for Erin. It was showing a Mexico hit just like this one. The GFDL, on the other hand, had called for a more northern track from the get go. In the end, the GFDL ended up being much better with that storm.

It seems like the GFS tends to have a left bias when dealing with western GOM storms...especially in the long range.

[Sanibel]

No chance Tracy. Relax. We have to worry about follow-up CV storms in September...


Can't wait to see what GFDL does with this over the next few days.

[BayouVenteux]

Jamaica should be in dread mode on this right now.

Ouch. Was that terrible pun intentional?

[cycloneye]

000
URNT12 KNHC 171614
VORTEX DATA MESSAGE AL042007
A. 17/15:59:50Z
B. 14 deg 40 min N
062 deg 54 min W
C. NA mb 2787 m
D. 69 kt
E. 215 deg 006 nm
F. 307 deg 065 kt
G. 215 deg 005 nm
H. 963 mb
I. NA C/ 3040 m
J. 18 C/ 3027 m
K. 11 C/ NA
L. CLOSED WALL
M. CO17-32
N. 12345/7
O. 0.02 / 2 nm
P. AF304 0404A DEAN OB 22
MAX FL WIND 115 KT NE QUAD 16:03:00 Z
INNER EYE OPEN SW-S
.

[tracyswfla]

No chance Tracy. Relax. We have to worry about follow-up CV storms in September...

I figured as much. I will continue with my plan to go to Orlando next week!

[miamicanes177]

This run of the GFS shows a broad area of low pressure at 30 hours. I am discounting this run completely.

[Chris_in_Tampa]

URNT12 KNHC 171614
VORTEX DATA MESSAGE AL042007
A. 17/15:59:50Z
B. 14 deg 40 min N
062 deg 54 min W
C. NA mb 2787 m
D. 69 kt
E. 215 deg 006 nm
F. 307 deg 065 kt
G. 215 deg 005 nm
H. 963 mb
I. NA C/ 3040 m
J. 18 C/ 3027 m
K. 11 C/ NA
L. CLOSED WALL
M. CO17-32
N. 12345/7
O. 0.02 / 2 nm
P. AF304 0404A DEAN OB 22
MAX FL WIND 115 KT NE QUAD 16:03:00 Z
INNER EYE OPEN SW-S

Storm DEAN: Observed By AF #304
Storm #04 in Atlantic Ocean1
Maximum Flight Level Winds Were 115KT (132.3mph 213.0km/h) In NE Quadrant At 16:03:00 Z
Estimated Max Surface Winds 103.5KT (119.0mph 191.7km/h) *
Misc Remarks: NER EYE OPEN SW-S.
Date/Time of Recon Report: Friday, August 17, 2007 11:59:00 AM (Fri, 17 Aug 2007 15:59:00 GMT)
Position of the center: 14° 40' N 062° 54' W (14.7°N 62.9°W) [See Map]

Surface Winds Were Estimated At: 69 KT (79.35MPH 127.8km/h)
Estimated Surface Winds Were Measured 006nm (6.9miles) From Center At Bearing 215°
Maximum Flight Level Winds Near Center Were 065KT (74.75mph 120.4km/h) From 307°
Maximum Flight Level Winds Were Measured 005nm (5.8 miles) From Center At Bearing 215°
Minimum pressure: 963 mb (28.44in)
Eye Wall Was Characterized As Being: CLOSED WALL
Eye Form Was Characterized As Being Concentric (Two Eyewalls) , CO17-32
Center Fix Established Using: Penetration Radar Wind Pressure Temperature
Center Fix Established At Level(s): 700mb
Navigational Accuracy Measured At 0.02nm
Meteorological Accuracy Measured At 2nm
* = Estimated Surface Winds are assumed 90% of Max Flight Level Winds

[Brent]

This run of the GFS shows a broad area of low pressure at 30 hours. I am discounting this run completely.

This bothers me big time... I don't like it.

[Sabanic]

5-6 days out . . . What is the percentage of confidence we should have in the models at this point? 25%? Maybe 30 %?

[fci]

If Dean makes a direct hit on Jamaica as a Cat 5 you might never be able to vacation there again.

It's funny how Jamaica almost seems to have a shield around and usually only gets sideswiped by the storms.

Lets hope their luck continues.

Caymans may get the worst of it.

[Extremeweatherguy]

138 hrs.. http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_138l.gif\

landfall in Mexico.

[tolakram]

H. 963 mb
I. NA C/ 3040 m
J. 18 C/ 3027 m
K. 11 C/ NA
L. CLOSED WALL
M. CO17-32
N. 12345/7
O. 0.02 / 2 nm
P. AF304 0404A DEAN OB 22
MAX FL WIND 115 KT NE QUAD 16:03:00 Z
INNER EYE OPEN SW-S

Storm DEAN: Observed By AF #304
Storm #04 in Atlantic Ocean1
Maximum Flight Level Winds Were 115KT (132.3mph 213.0km/h) In NE Quadrant At 16:03:00 Z
Estimated Max Surface Winds 103.5KT (119.0mph 191.7km/h) *
Misc Remarks: NER EYE OPEN SW-S.
Date/Time of Recon Report: Friday, August 17, 2007 11:59:00 AM (Fri, 17 Aug 2007 15:59:00 GMT)
Position of the center: 14° 40' N 062° 54' W (14.7°N 62.9°W) [See Map]

Surface Winds Were Estimated At: 69 KT (79.35MPH 127.8km/h)
Estimated Surface Winds Were Measured 006nm (6.9miles) From Center At Bearing 215°
Maximum Flight Level Winds Near Center Were 065KT (74.75mph 120.4km/h) From 307°
Maximum Flight Level Winds Were Measured 005nm (5.8 miles) From Center At Bearing 215°
Minimum pressure: 963 mb (28.44in)
Eye Wall Was Characterized As Being: CLOSED WALL
Eye Form Was Characterized As Being Concentric (Two Eyewalls) , CO17-32
Center Fix Established Using: Penetration Radar Wind Pressure Temperature
Center Fix Established At Level(s): 700mb
Navigational Accuracy Measured At 0.02nm
Meteorological Accuracy Measured At 2nm
* = Estimated Surface Winds are assumed 90% of Max Flight Level Winds

OK, this explains the infrared, it looks like an eyewall replacement cycle (ERC) is going on. Is that correct?