ATL: BRET - Remnants - Discussion

[Zampanò]

Very poor call again from the NHC given plenty of evidence of 35kts...ah well they've been behind the curve eright from the get-go!

I feel the NHC's conservative policy is the best one with a storm that is not immediately threatening land. No reason to be in a hurry to upgrade, let's see how it holds together.

(First post, by the way. Greetings to all.)

[cycloneye]

Discussion came out late.


TROPICAL DEPRESSION TWO DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL022011
500 PM EDT SUN JUL 17 2011

AN AIR FORCE HURRICANE HUNTER PLANE INVESTIGATING THE LOW PRESSURE
AREA JUST NORTH OF THE NORTHWEST BAHAMAS FOUND A WELL-DEFINED
LOW-LEVEL CENTER OF CIRCULATION...AND THE SYSTEM IS BEING
DESIGNATED AS A TROPICAL CYCLONE AT THIS TIME. ALTHOUGH WINDS OF
TROPICAL STORM FORCE WERE MEASURED BY THE SFMR INSTRUMENT ON BOARD
THE PLANE...THESE OBSERVATIONS WERE FLAGGED AS QUESTIONABLE. PEAK
FLIGHT-LEVEL WINDS REPORTED BY THE AIRCRAFT WERE 44 KT WHICH WOULD
NORMALLY INDICATE A SYSTEM OF TROPICAL STORM STRENGTH. HOWEVER...
THE CONVECTION NEAR THE CENTER IS RELATIVELY WEAK...AND IN THIS
CASE THE STRONGEST WINDS ARE LIKELY NOT MIXING DOWN TO THE SURFACE
AS MUCH AS TYPICALLY OCCURS. THE CURRENT INTENSITY ESTIMATE IS 30
KT. THE ATMOSPHERIC ENVIRONMENT IS NOT IDEAL FOR STRENGTHENING
WITH SOME DRIER AIR JUST TO THE NORTH AND NORTHWEST OF THE CYCLONE.
THE OFFICIAL INTENSITY FORECAST CLOSELY FOLLOWS THE LGEM AND
INTENSITY CONSENSUS GUIDANCE. NONE OF THE CURRENT MODEL RUNS SHOW
THE SYSTEM STRENGTHENING INTO A HURRICANE.

INITIAL MOTION IS A SOUTHWARD DRIFT. STEERING CURRENTS ARE LIKELY
TO REMAIN QUITE WEAK OVER THE NEXT DAY OR SO...AS THE SYSTEM IS
SITUATED IN A WEAKNESS IN THE SUBTROPICAL RIDGE. IN A COUPLE
OF DAYS...THE MID-LEVEL RIDGE TO THE SOUTHEAST OF THE TROPICAL
CYCLONE IS FORECAST TO STRENGTHEN SLIGHTLY AND THIS...ALONG WITH A
WEAK TROUGH PASSING NORTH OF THE CYCLONE...SHOULD INDUCE A GENERAL
NORTHEASTWARD MOTION. LATER IN THE FORECAST PERIOD...THE TRACK
GUIDANCE IS IN FAIRLY GOOD AGREEMENT ON AN EAST-NORTHEASTWARD
MOTION AT AN INCREASING FORWARD SPEED. THE OFFICIAL FORECAST IS
RATHER CLOSE TO THE MODEL CONSENSUS AND TO THE LATEST ECMWF TRACK.

FORECAST POSITIONS AND MAX WINDS

INIT 17/2100Z 27.5N 78.2W 30 KT 35 MPH
12H 18/0600Z 27.4N 78.2W 40 KT 45 MPH
24H 18/1800Z 28.2N 77.8W 45 KT 50 MPH
36H 19/0600Z 29.0N 77.3W 50 KT 60 MPH
48H 19/1800Z 30.4N 76.5W 50 KT 60 MPH
72H 20/1800Z 32.0N 73.5W 50 KT 60 MPH
96H 21/1800Z 34.0N 67.0W 45 KT 50 MPH
120H 22/1800Z 36.0N 60.0W 40 KT 45 MPH

$$
FORECASTER PASCH/STEWART

[KWT]

Very poor call again from the NHC given plenty of evidence of 35kts...ah well they've been behind the curve eright from the get-go!

I feel the NHC's conservative policy is the best one with a storm that is not immediately threatening land. No reason to be in a hurry to upgrade, let's see how it holds together.

Hi there!

Whilst thats true, it is over the Bahamas at the moment and I think recon and the constant sampling of 35-40kts backed up by BOTH FL and surface estimates should be enough...I mean I've seen the NHC upgrade based on ONE report of 35kts by surface estimate!

[cycloneye]

Very poor call again from the NHC given plenty of evidence of 35kts...ah well they've been behind the curve eright from the get-go!

I feel the NHC's conservative policy is the best one with a storm that is not immediately threatening land. No reason to be in a hurry to upgrade, let's see how it holds together.

Hi there!

Whilst thats true, it is over the Bahamas at the moment and I think recon and the constant sampling of 35-40kts backed up by BOTH FL and surface estimates should be enough...I mean I've seen the NHC upgrade based on ONE report of 35kts by surface estimate!

From discussion.

ALTHOUGH WINDS OF
TROPICAL STORM FORCE WERE MEASURED BY THE SFMR INSTRUMENT ON BOARD
THE PLANE...THESE OBSERVATIONS WERE FLAGGED AS QUESTIONABLE. PEAK
FLIGHT-LEVEL WINDS REPORTED BY THE AIRCRAFT WERE 44 KT WHICH WOULD
NORMALLY INDICATE A SYSTEM OF TROPICAL STORM STRENGTH. HOWEVER...
THE CONVECTION NEAR THE CENTER IS RELATIVELY WEAK...AND IN THIS
CASE THE STRONGEST WINDS ARE LIKELY NOT MIXING DOWN TO THE SURFACE
AS MUCH AS TYPICALLY OCCURS.

[WxEnthus]

000
URNT15 KNHC 172043
AF304 01BBA INVEST HDOB 30 20110717
203230 2749N 07732W 9668 00428 0161 +186 +168 107031 033 036 015 00
203300 2750N 07732W 9748 00359 0162 +191 +167 104029 030 032 012 00
203330 2752N 07732W 9803 00309 0159 +198 +165 101027 027 032 014 00
203400 2753N 07732W 9809 00303 0159 +196 +165 100026 027 031 014 00
203430 2755N 07731W 9816 00297 0160 +196 +166 105026 026 032 013 00
203500 2757N 07731W 9806 00308 0161 +200 +166 105026 026 029 012 00
203530 2758N 07731W 9815 00298 0161 +198 +166 106026 026 031 010 00
203600 2800N 07731W 9808 00306 0161 +200 +166 103027 028 031 010 00
203630 2801N 07731W 9810 00304 0161 +197 +167 105029 029 033 016 00
203700 2803N 07731W 9817 00298 0162 +190 +169 105027 028 037 015 00
203730 2804N 07731W 9810 00304 0162 +198 +169 104026 027 033 012 00
203800 2806N 07731W 9812 00303 0164 +190 +169 103025 025 033 013 03
203830 2807N 07732W 9806 00309 0164 +198 +169 100026 026 /// /// 03
203900 2807N 07733W 9887 00238 0163 +199 +170 092023 024 030 010 03
203930 2805N 07734W 9924 00203 0160 +208 +172 089023 024 032 008 00
204000 2804N 07735W 9918 00208 0159 +210 +173 087024 024 033 010 00
204030 2803N 07737W 9921 00205 0159 +205 +175 080023 024 033 013 00
204100 2802N 07738W 9922 00203 0158 +201 +176 086022 023 034 012 00
204130 2800N 07739W 9920 00203 0157 +196 +177 095026 027 034 012 00
204200 2759N 07740W 9922 00202 0157 +197 +177 099027 027 040 014 00
$$
;

[HURAKAN]

Latest loop

[HurricaneBrain]

I don't understand why some people think this is going into the gulf...

[Hurricaneman]

This is a start, they expect out to sea, but theres just as much chance this goes closer to the carolina coastline

[KWT]

I feel thats still a very poor call from the NHC though cycloneye, I mean they are effectivly just ignoring recons reports totally. A bit too wishy-washy for me...

So both areas confirmed TS winds yet they choose 30kts...me thinks its to save face after an awful call from those two just 4-6hrs earlier

not much model info for them to go onreally given most models didn't really catch this system too well.

PS, they probably don't want to get burned by upgrading only for the system to effectivly poof!

[WxEnthus]

[srainhoutx]

Very poor call again from the NHC given plenty of evidence of 35kts...ah well they've been behind the curve eright from the get-go!

I can only guess they think its weakened a touch over the last hour or two and hence goingwith a much more conservative figure.

Ps, estimate of 35kts again at the surface, 38kts this time round.

What?

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 17th day of the month at 20:37Z
Corrected: This observation corrected a previous observation.
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)
Mission Purpose: Investigate second suspect area (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 14
A. Time of Center Fix: 17th day of the month at 20:16:40Z
B. Center Fix Coordinates: 27°34'N 78°11'W (27.5667N 78.1833W)
B. Center Fix Location: 130 miles (209 km) to the ENE (63°) from West Palm Beach, FL, USA.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 24kts (~ 27.6mph)
E. Location of the Estimated Maximum Surface Wind: 5 nautical miles (6 statute miles) to the NW (310°) of center fix
F. Maximum Flight Level Wind Inbound: From 60° at 25kts (From the ENE at ~ 28.8mph)
G. Location of Maximum Flight Level Wind Inbound: 2 nautical miles (2 statute miles) to the NW (320°) of center fix
H. Minimum Sea Level Pressure: 1010mb (29.83 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 23°C (73°F) at a pressure alt. of 189m (620ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 24°C (75°F) at a pressure alt. of 188m (617ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 21°C (70°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Radar, Wind and Pressure
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 1,500 feet
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1 nautical mile
Remarks Section:
Maximum Wind Outbound: 42kts (~ 48.3mph) in the east quadrant at 20:25:40Z
Maximum Flight Level Wind: 42kts (~ 48.3mph) in the east quadrant at 20:25:40Z
Sea Level Pressure Extrapolation From: Below 1,500 feet

[WxEnthus]

000
URNT15 KNHC 172052
AF304 01BBA INVEST HDOB 31 20110717
204230 2758N 07741W 9920 00202 0157 +188 +177 097027 028 042 017 03
204300 2757N 07743W 9924 00196 0154 +180 +177 092028 029 058 026 00
204330 2755N 07744W 9918 00199 0152 +180 +175 089031 031 054 040 00
204400 2754N 07745W 9922 00192 0148 +179 +174 083034 035 055 043 00
204430 2753N 07746W 9919 00194 0146 +181 +172 076037 037 049 039 00
204500 2751N 07748W 9923 00188 0141 +182 +172 069039 042 057 043 00
204530 2750N 07749W 9918 00187 0136 +184 +171 060042 043 060 032 00
204600 2748N 07750W 9914 00191 0134 +186 +172 062038 041 057 035 00
204630 2747N 07751W 9918 00185 0136 +180 +173 060036 041 054 051 00
204700 2745N 07752W 9932 00178 0140 +192 +174 068024 027 059 046 03
204730 2744N 07753W 9912 00196 0136 +223 +175 070008 013 037 009 00
204800 2743N 07754W 9923 00180 0131 +231 +178 008006 008 024 009 00
204830 2741N 07755W 9923 00179 0130 +226 +181 028007 010 025 007 00
204900 2740N 07756W 9919 00182 0131 +211 +184 036008 011 028 009 00
204930 2738N 07757W 9923 00178 0130 +204 +186 051009 010 033 010 00
205000 2737N 07758W 9918 00184 0130 +215 +186 085010 013 030 010 03
205030 2736N 07758W 9913 00187 0126 +230 +187 148015 016 028 007 03
205100 2734N 07759W 9926 00171 0123 +230 +188 154018 020 028 002 03
205130 2733N 07800W 9921 00171 0118 +233 +190 161022 024 027 003 00
205200 2732N 07801W 9928 00158 0111 +229 +194 170026 028 031 003 03
$$
;

[KWT]

srainhoutx, take a look at the recon thread...plenty of 38-45kts FL reports and plenty of 35-40kts SMFR reports.

[lester]

A bunch if 40 kt FL winds

Upgrade please

[srainhoutx]

srainhoutx, take a look at the recon thread...plenty of 38-45kts FL reports and plenty of 35-40kts SMFR reports.

SMRF data is notorious for errors. We see this year in and year out. I strongly suggest the NHC does know what they are doing and are highly trained forecasters that specialize in forecasting cyclones.

[Ivanhater]

55-60 kt on the SFMR unflagged

[vbhoutex]

Very poor call again from the NHC given plenty of evidence of 35kts...ah well they've been behind the curve eright from the get-go!

I feel the NHC's conservative policy is the best one with a storm that is not immediately threatening land. No reason to be in a hurry to upgrade, let's see how it holds together.

(First post, by the way. Greetings to all.)

Greetings to you also. Glad you are joining in our discussions from the start.

[Hurricaneman]

If there is evidence of TS winds, they would put out a special statement. I see no special statement so no TS at the moment

[WxEnthus]

Flight so far:



Latest, close up:

[HURAKAN]

55-60 kt on the SFMR unflagged

Although unflagged, seems wrong because the flight level winds are lower than those values