ATL: FOUR - Remnants - Discussion

[RL3AO]

Subtle and important differences between the GFS and Euro in terms of trough strength and west Atlantic ridge.

[cycloneye]

Things are beggining to jell.

@TropicalTidbits
Low-level vorticity (spin) is increasing in the vicinity of 8N, 33W. The first signs of significant organization of Invest #94L.

 https://twitter.com/TropicalTidbits/status/881856260232105986

[RL3AO]

It looks like the famous east coast trough will appear to curve 94L out to sea

Euro has a day 9/10 pattern that could me more of a US threat. Let's not throw it to the fishes yet.

[msbee]

Before it gets to you guys it looks likely to go over Puerto Rico.....No SAL to speak of, no shear, warm water. Someone tell me I'm wrong....

I appreciate everyone's concern and interests, but please don't forget that there are many of us here who live in the Northern Caribbean islands. We are very vulnerable to flooding with even just a tropical storm, so don't forget us and our concerns. Any comments and analyses from all of you about the Caribbean islands risks, who would be first in the line of fire, would be greatly appreciated.
Thank you from St Maarten

[xironman]

It looks like the famous east coast trough will appear to curve 94L out to sea

Not sure, the Euro ensembles seem to show a much weaker trough. I tend to like them better at that range, but at that range lots will change.

Sorry I guess RL3AO covered it.

[Hurricane Andrew]

Art this point, we have enough trouble predicting where a storm will go in the D3-D5 range. Making definitive claims beyond that is hasty at best, and dangerous at worst. What we can get is synoptic "clues", but they are just that; clues. Not proof. So far, our friendly neighborhood invest has sat pretty happily around 10N. The model tracks I have seen show it immediately beginning to gain latitude. Just some food for thought.

I believe that 20/70 is a pretty good call, although I expect to see those numbers slowly bumped up every TWO. The EURO does not develop this, which although it is an outlier, would preclude me personally from giving this a "near 100%" in the 5-day TWO.

She is organizing, albeit slowly, so at this point all we can do is wait and watch, and try to interpret the vague images shown to us from the long-range models. Exact tracks at D7-D10 are pointless; focus on the upper levels; one run is unimportant, look at trends. That is my advice, at least, I am no pro.

The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the NHC and NWS.

[GCANE]

For this time of year and in this location, very impressive convergence.

http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

[Hurricane Andrew]

Cycloneye, why do the model tracks show 94L gaining so much latitude immediately, even moving in a NNW fashion for a period of time? From my interpretation of the satellite loop, the current storm motion is somewhere between 270 and 300, nowhere near NNW or even NW. Am I missing something?

[cycloneye]

Cycloneye, why do the model tracks show 94L gaining so much latitude immediately, even moving in a NNW fashion for a period of time? From my interpretation of the satellite loop, the current storm motion is somewhere between 270 and 300, nowhere near NNW or even NW. Am I missing something?

A small weakness area that fills in later.

[Hurricane Andrew]

For this time of year and in this location, very impressive convergence.

http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

Probably aided by our friends the westerlies, at least if I understood the previous discussions in Talking Tropics correctly. Very interesting for sure.

[Hurricaneman]

Some GFS ensembles have it turn west in the long run when 0z had none doing so so maybe a shift in the 12 z run?

[Hurricane Andrew]

Cycloneye, why do the model tracks show 94L gaining so much latitude immediately, even moving in a NNW fashion for a period of time? From my interpretation of the satellite loop, the current storm motion is somewhere between 270 and 300, nowhere near NNW or even NW. Am I missing something?

A small weakness area that fills in later.

Ohhh, that makes sense. Are we seeing this weakness currently opening up? I presume it would be visible on WV imagery...I am still somewhat uncertain at interpreting realtime 500 data.

[Hurricane Andrew]

Also, does anyone have a link to the SHIPS output?

[RL3AO]

GFS keeps developing a very intense ridge over central Canada with two deep troughs on either side. Almost looks like an omega block pattern. Euro is not as aggressive with the Canadian ridge. As a result, we see a weaker east coast trough. That would be a big synoptic pattern to watch in coming days. If you want to see it stay out to sea, root for heat on the shores of Hudson Bay.

[cycloneye]

Also, does anyone have a link to the SHIPS output?

ftp://ftp.nhc.noaa.gov/atcf/stext/

[cycloneye]

* ATLANTIC SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* INVEST AL942017 07/03/17 12 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 25 29 33 36 41 50 58 65 72 76 77 77 76
V (KT) LAND 25 29 33 36 41 50 58 65 72 76 77 77 76
V (KT) LGEM 25 27 30 32 35 39 43 48 54 59 61 61 61
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 8 11 16 20 23 14 10 2 7 3 4 6 12
SHEAR ADJ (KT) 0 1 2 0 -5 -2 0 2 0 1 9 8 7
SHEAR DIR 100 62 48 46 42 32 44 259 283 258 297 216 277
SST (C) 27.8 27.8 27.9 28.0 27.9 27.3 26.4 25.7 26.5 27.1 27.3 27.2 27.1
POT. INT. (KT) 130 130 131 131 133 129 121 116 123 128 129 126 126
ADJ. POT. INT. 124 124 124 124 128 130 125 119 125 126 123 117 118
200 MB T (C) -54.4 -54.2 -54.5 -54.9 -54.8 -54.8 -54.8 -54.2 -54.6 -54.2 -54.6 -53.9 -54.1
200 MB VXT (C) 0.0 0.0 0.0 0.0 0.0 -0.1 -0.2 -0.2 -0.1 -0.1 0.0 0.1 0.4
TH_E DEV (C) 5 5 5 5 5 5 5 6 7 8 8 8 8
700-500 MB RH 67 72 74 77 79 78 72 64 58 56 55 56 59
MODEL VTX (KT) 7 9 10 11 13 15 15 15 17 18 17 17 17
850 MB ENV VOR 48 45 40 28 27 21 14 23 38 44 35 13 -12
200 MB DIV 64 76 83 87 83 83 35 27 28 62 91 43 32
700-850 TADV 0 0 0 0 -2 -9 -2 18 15 7 11 8 17
LAND (KM) 1740 1756 1761 1764 1769 1785 1951 1794 1630 1485 1300 1175 1149
LAT (DEG N) 9.0 8.8 8.6 8.5 8.7 10.3 12.7 15.3 17.1 17.8 17.9 18.4 20.0
LONG(DEG W) 32.4 32.5 32.5 32.5 32.6 33.3 35.7 39.5 44.1 48.2 51.4 53.4 54.9
STM SPEED (KT) 3 2 1 1 4 13 21 24 22 17 12 9 12
HEAT CONTENT 13 13 13 13 13 16 3 2 13 10 12 15 9

FORECAST TRACK FROM TABM INITIAL HEADING/SPEED (DEG/KT):190/ 3 CX,CY: 0/ -2
T-12 MAX WIND: 20 PRESSURE OF STEERING LEVEL (MB): 622 (MEAN=618)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 19.3 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 74.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 55 KT IN 48 HR): 3.8

INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
6 12 18 24 36 48 60 72 84 96 108 120
----------------------------------------------------------
SAMPLE MEAN CHANGE 1. 2. 3. 4. 6. 8. 9. 10. 11. 12. 13. 13.
SST POTENTIAL 1. 1. 1. 3. 6. 11. 16. 20. 24. 27. 28. 30.
VERTICAL SHEAR MAG 1. 1. 1. 1. 1. 1. 3. 4. 5. 6. 7. 7.
VERTICAL SHEAR ADJ 0. -0. 0. 0. 1. 2. 2. 2. 2. 1. -0. -1.
VERTICAL SHEAR DIR 0. 1. 2. 3. 5. 7. 9. 8. 7. 6. 5. 4.
PERSISTENCE 1. 1. 2. 2. 2. 2. 1. 1. 1. 0. 0. -0.
200/250 MB TEMP. -0. -0. -0. -0. -0. 0. 0. 0. 1. 1. 2. 2.
THETA_E EXCESS -0. -0. -1. -1. -1. -1. -1. -2. -2. -2. -2. -2.
700-500 MB RH -0. -0. -1. -1. -2. -4. -5. -5. -6. -5. -5. -4.
MODEL VTX TENDENCY 0. 1. 2. 3. 6. 7. 7. 9. 9. 7. 6. 5.
850 MB ENV VORTICITY 0. 0. 0. 0. 0. 0. -0. 0. 0. 0. 0. -0.
200 MB DIVERGENCE 0. 0. 1. 1. 1. 1. 1. 1. 1. 1. 0. -1.
850-700 T ADVEC 0. -0. -0. -0. -0. -1. -0. -0. 0. 0. 0. 0.
ZONAL STORM MOTION 0. -0. -0. -0. -1. -1. -1. -1. -2. -2. -3. -3.
STEERING LEVEL PRES -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0.
DAYS FROM CLIM. PEAK 0. 0. 0. 0. 0. 0. 1. 1. 1. 2. 2. 2.
GOES PREDICTORS 0. 1. 1. 1. 1. 1. 0. -0. -1. -1. -1. -1.
OCEAN HEAT CONTENT -0. -0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -0.
----------------------------------------------------------
TOTAL CHANGE 4. 8. 11. 16. 25. 33. 40. 47. 51. 52. 52. 51.

CURRENT MAX WIND (KT): 25. LAT, LON: 9.0 32.4

** 2017 ATLANTIC RI INDEX AL942017 INVEST 07/03/17 12 UTC **
(SHIPS-RII PREDICTOR TABLE for 30 KT OR MORE MAXIMUM WIND INCREASE IN NEXT 24-h)

Predictor Value RI Predictor Range Scaled Value(0-1) % Contribution
12 HR PERSISTENCE (KT): 5.0 -49.5 to 33.0 0.66 4.5
850-200 MB SHEAR (KT) : 15.5 30.1 to 2.9 0.54 1.4
HEAT CONTENT (KJ/cm2) : 13.0 0.0 to 156.2 0.08 0.2
2nd PC OF IR BR TEMP : 0.6 2.4 to -3.0 0.33 0.9
STD DEV OF IR BR TEMP : 19.3 36.6 to 2.8 0.51 1.5
MAXIMUM WIND (kt) : 25.0 22.5 to 121.0 0.07 0.1
POT = MPI-VMAX (KT) : 100.0 28.4 to 139.6 0.64 1.2
D200 (10**7s-1) : 78.6 -29.7 to 181.5 0.51 0.4
BL DRY-AIR FLUX (w/m2): 49.4 961.4 to -67.1 0.89 0.0
% AREA WITH TPW <45 mm: 0.0 100.0 to 0.0 1.00 0.1

SHIPS Prob RI for 20kt/ 12hr RI threshold= 5% is 0.9 times sample mean ( 5.4%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 14% is 1.2 times sample mean (11.5%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 10% is 1.4 times sample mean ( 7.4%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 6% is 1.4 times sample mean ( 4.3%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 0% is 0.0 times sample mean ( 2.8%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 0% is 0.0 times sample mean ( 5.1%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 11% is 2.0 times sample mean ( 5.3%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 0% is 0.0 times sample mean ( 6.0%)

Matrix of RI probabilities
------------------------------------------------------------------------------
RI (kt / h) | 20/12 | 25/24 | 30/24 | 35/24 | 40/24 | 45/36 | 55/48 |65/72
------------------------------------------------------------------------------
SHIPS-RII: 4.7% 13.8% 10.4% 6.0% 0.0% 0.0% 10.8% 0.0%
Logistic: 3.1% 9.9% 3.9% 0.7% 0.5% 2.9% 6.4% 7.3%
Bayesian: 2.4% 9.2% 1.3% 0.0% 0.0% 0.3% 0.4% 0.7%
Consensus: 3.4% 11.0% 5.2% 2.3% 0.2% 1.1% 5.9% 2.7%

** PROBLTY OF AT LEAST 1 SCNDRY EYEWL FORMTN EVENT AL942017 INVEST 07/03/2017 12 UTC **
TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48)
CLIMO(%) 0 0( 0) 0( 0) 0( 0) <-- PROB BASED ON INTENSITY ONLY
PROB(%) 0 0( 0) 0( 0) 0( 0) <-- FULL MODEL PROB (RAN NORMALLY)

** DSHIPS INTENSITY FORECAST ADJUSTED RELATIVE TO ONSET OF ERC WEAKENING PHASE **
TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
>24HR AGO (DSHIPS) 25 29 33 36 41 50 58 65 72 76 77 77 76
18HR AGO 25 24 28 31 36 45 53 60 67 71 72 72 71
12HR AGO 25 22 21 24 29 38 46 53 60 64 65 65 64
6HR AGO 25 19 16 15 20 29 37 44 51 55 56 56 55
NOW CURRENT INTENSITY < 83 KT
IN 6HR INTENSITY IN 6HR < 83 KT
IN 12HR

[wxman57]

Also, does anyone have a link to the SHIPS output?

Ships output for 94L is here:
ftp://ftp.nhc.noaa.gov/atcf/stext/17070312AL9417_ships.txt

Main link to Ships output:
ftp://ftp.nhc.noaa.gov/atcf/stext/

[Hurricane Andrew]

Many thanks to both of you. I had the link a while back, and lost it.,

[WeatherEmperor]

Very hard to fully buy into the OTS scenario at this point when the NAO is forecast to be very positive in the next 7-10 days. Maybe the NAO doesnt have that much affect afterall on trof/ridge setups? Luckily, we have a loooong time to go here




Sent from my iPhone 7 using Tapatalk

[Hurricane Andrew]

I really don't know how I feel about the models taking 94L on a NNE direction in the D1-D2 range...seems a bit extreme unless the center reforms. Even with a weakness, would that not lead to a NNW direction at the most? NNE seems very, very strange unless a trough is present.

Someone please help, I am confused.