ATL: IRMA - Models

[jlauderdal]

You can download, upload to an image site, and post.

930 in the bahamas will get peoples attention

[Digital-TC-Chaser]

The early 5d south dip is recovered on tvcn consensus track .

[NDG]

12z models.

[cycloneye]

[RL3AO]

12z models.

The orange line that goes out to sea is a useful piece of information. That's basically climatology. Already suggests this is an unusual system compared to climo.

[gatorcane]

00Z ECMWF moves this right through the Hebert box. By the way the NE Lesser Antilles and Puerto Rico are going to be the first concern here:

[caneman]

soflcane has been optimistic all morning about a recurve, lets see what happens

I'm in agreeable with SoFloCane. Id be shocked if it didn't recurve

based on climatology or modeling?

Based on climo, current positioning and current strength

[perk]

Based on its current location alone right now YES i'd be floored if it makes past 70-75w but it could happen so we watch and see. Watching evolution of WPAC recurving typhoon.

Man when you are in a hole put the shovel down,this far out nobody knows where 93L will go.

[sma10]

 https://twitter.com/TropicalTidbits/status/902869681400360961

We can debate all we want, but ultimately this post from Levi is the most relevant.

Watch this interaction between Irma and the trough this weekend, and it will tell us all we need to know as to whether there will be a legitimate threat to US.

[TheStormExpert]

12z models.

Some of those 06z GEFS GFS Ensembles have it hooking west at the end.

[chris_fit]

Based on the 12Z Spaghetti plots - that does look fishy.

[cycloneye]

Shear for IRMA will be almost light.

ATLANTIC SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* IRMA AL112017 08/30/17 12 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 40 47 53 58 63 69 74 75 77 78 80 83 86
V (KT) LAND 40 47 53 58 63 69 74 75 77 78 80 83 86
V (KT) LGEM 40 47 53 59 64 71 74 75 75 76 79 83 88
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 3 2 1 4 4 5 7 6 7 8 3 2 6
SHEAR ADJ (KT) 0 0 0 1 3 0 0 -2 0 -5 0 2 -1
SHEAR DIR 30 34 17 40 76 193 266 240 250 207 209 108 334
SST (C) 27.5 27.3 27.2 27.2 27.1 26.7 26.4 26.3 26.5 26.8 27.4 27.9 28.0
POT. INT. (KT) 132 128 125 125 124 120 118 118 121 124 130 134 133
ADJ. POT. INT. 129 121 116 115 114 111 109 110 115 119 123 124 121
200 MB T (C) -53.6 -53.4 -53.5 -53.8 -53.6 -53.4 -53.7 -53.4 -53.7 -53.5 -53.7 -53.5 -53.7
200 MB VXT (C) 0.0 0.0 0.0 0.1 0.2 0.3 0.4 0.2 0.2 0.3 0.4 0.4 0.4
TH_E DEV (C) 7 7 7 7 7 7 7 8 8 9 9 9 9
700-500 MB RH 70 67 65 64 62 59 54 46 42 42 46 49 51
MODEL VTX (KT) 13 14 14 14 15 15 16 15 15 15 16 17 19
850 MB ENV VOR 54 61 60 52 56 70 62 55 57 77 89 89 89
200 MB DIV 34 28 29 37 32 23 39 42 -7 -7 6 1 3
700-850 TADV 4 0 -2 -1 3 6 7 0 5 -3 0 -1 -2
LAND (KM) 1328 1468 1554 1629 1687 1800 1925 2143 2114 1841 1564 1373 1311
LAT (DEG N) 16.4 16.6 16.7 16.8 17.2 18.3 19.5 20.3 20.1 19.2 17.7 16.4 16.1
LONG(DEG W) 29.8 31.1 31.9 32.6 33.1 34.0 35.4 37.6 40.7 43.8 46.3 47.6 48.3
STM SPEED (KT) 14 10 7 6 6 8 10 13 15 15 12 7 3
HEAT CONTENT 6 6 7 8 5 4 3 10 15 18 29 26 25

FORECAST TRACK FROM TABM INITIAL HEADING/SPEED (DEG/KT):280/ 16 CX,CY: -15/ 3
T-12 MAX WIND: 25 PRESSURE OF STEERING LEVEL (MB): 535 (MEAN=618)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 8.0 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 99.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 55 KT IN 48 HR): 14.7

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. 2. 3. 4. 6. 8. 10. 11. 13. 13. 14.
VERTICAL SHEAR MAG 1. 2. 4. 5. 8. 10. 12. 13. 13. 14. 15. 14.
VERTICAL SHEAR ADJ 0. 0. 0. -0. -0. 0. 1. 1. 2. 2. 2. 2.
VERTICAL SHEAR DIR 0. 1. 1. 2. 2. 2. 1. 0. -1. -2. -1. -1.
PERSISTENCE 3. 5. 6. 6. 6. 5. 4. 3. 2. 1. -1. -2.
200/250 MB TEMP. -0. -1. -1. -1. -1. -1. -1. -1. -1. -1. -1. -0.
THETA_E EXCESS -0. -0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -1.
700-500 MB RH -0. -0. -0. -1. -1. -1. -2. -1. -1. -0. -0. -0.
MODEL VTX TENDENCY -0. -0. -0. 0. -0. 0. -1. -1. -2. -2. -1. 1.
850 MB ENV VORTICITY 0. 0. 0. 0. 1. 1. 1. 2. 2. 2. 3. 3.
200 MB DIVERGENCE -0. -0. -0. -0. -0. -0. -0. -0. -1. -0. -0. 0.
850-700 T ADVEC 0. -0. -0. -0. -0. 0. -0. 0. -0. -0. -0. -0.
ZONAL STORM MOTION -0. 0. 0. 1. 2. 2. 2. 2. 3. 3. 4. 4.
STEERING LEVEL PRES 0. 0. 0. 0. 1. 1. 1. 1. 1. 1. 1. 1.
DAYS FROM CLIM. PEAK -0. -0. -0. -0. -0. -0. -0. -0. -0. -1. -1. -1.
GOES PREDICTORS 1. 2. 3. 3. 4. 3. 2. 1. 0. -0. -1. -0.
OCEAN HEAT CONTENT -0. -0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -0.
----------------------------------------------------------
TOTAL CHANGE 7. 13. 18. 23. 29. 34. 35. 37. 38. 40. 43. 46.

CURRENT MAX WIND (KT): 40. LAT, LON: 16.4 29.8

** 2017 ATLANTIC RI INDEX AL112017 IRMA 08/30/17 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): 15.0 -49.5 to 33.0 0.78 10.4
850-200 MB SHEAR (KT) : 3.2 30.1 to 2.9 0.99 5.2
HEAT CONTENT (KJ/cm2) : 6.4 0.0 to 156.2 0.04 0.2
2nd PC OF IR BR TEMP : 0.2 2.4 to -3.0 0.40 2.2
STD DEV OF IR BR TEMP : 8.0 36.6 to 2.8 0.85 4.7
MAXIMUM WIND (kt) : 40.0 22.5 to 121.0 0.49 1.4
POT = MPI-VMAX (KT) : 79.0 28.4 to 139.6 0.46 1.7
D200 (10**7s-1) : 32.0 -29.7 to 181.5 0.29 0.5
BL DRY-AIR FLUX (w/m2): 178.4 961.4 to -67.1 0.76 0.0
% AREA WITH TPW <45 mm: 0.0 100.0 to 0.0 1.00 0.2

SHIPS Prob RI for 20kt/ 12hr RI threshold= 13% is 2.3 times sample mean ( 5.4%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 37% is 3.2 times sample mean (11.5%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 26% is 3.6 times sample mean ( 7.4%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 16% is 3.7 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= 21% is 4.0 times sample mean ( 5.1%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 20% is 3.7 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: 12.6% 37.1% 26.5% 15.7% 0.0% 20.5% 19.8% 0.0%
Logistic: 23.8% 42.8% 29.0% 16.5% 13.1% 23.9% 29.7% 28.6%
Bayesian: 39.2% 71.4% 52.8% 29.0% 7.4% 23.3% 9.0% 0.2%
Consensus: 25.2% 50.4% 36.1% 20.4% 6.8% 22.5% 19.5% 9.6%

** PROBLTY OF AT LEAST 1 SCNDRY EYEWL FORMTN EVENT AL112017 IRMA 08/30/2017 12 UTC **
TIME(HR) 0-12 12-24(0-24) 24-36(0-36) 36-48(0-48)
CLIMO(%) 0 0( 0) 0( 0) ***(***) <-- PROB BASED ON INTENSITY ONLY
PROB(%) 0 0( 0) 0( 0) ERR <-- 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) 40 47 53 58 63 69 74 75 77 78 80 83 86
18HR AGO 40 39 45 50 55 61 66 67 69 70 72 75 78
12HR AGO 40 37 36 41 46 52 57 58 60 61 63 66 69
6HR AGO 40 34 31 30 35 41 46 47 49 50 52 55 58
NOW CURRENT INTENSITY < 83 KT
IN 6HR INTENSITY IN 6HR < 83 KT
IN 12HR INTENSITY IN 12HR < 83 KT

[RL3AO]

Based on the 12Z Spaghetti plots - that does look fishy.

Of course what isn't on the spaghetti plots is the Euro and its ensembles. See Alan Brammer's image below.

[SouthDadeFish]

In my opinion, it's way too early to have any kind of confidence in a potential impact to the US. The recurving typhoon in the WPAC (Sanvu) is going to throw off the predictability of the medium-long range pattern. I think the main issue right now is whether 93L/Irma will affect the northern Antilles. Any deviation from the 00Z EC track to the SW would bring the core of the system directly over the islands. We will likely have a very strong hurricane on our hands in the 7-10 day time frame, so this is a serious threat. Any impacts to the islands though is likely at least 7 days away, so there is plenty of time for things to change. Hopefully the TC follows a track closer to the GFS in the medium-range.

[GCANE]

Latest COAMPS
Interesting.
Cat 1 momentarily and then due west.

[gatorcane]

The GFS has been rather inconsistent with this system. Yesterday it dropped development which of course was highly suspect. ECMWF seems more consistent so would lean towards the ECMWF solution at this point.

[Exalt]

You can download, upload to an image site, and post.

930 in the bahamas will get peoples attention

High Cat 4 or low-end Cat 5? Better pull a Joaquin and recurve real quick.

[SouthFLTropics]

The GFS has been rather inconsistent with this system. Yesterday it dropped development which of course was highly suspect. ECMWF seems more consistent so would lean towards the ECMWF solution at this point.

Your point is valid Gatorcane but you also have to take into account the sampling size. It's hard to compare the results of the GFS to the Euro when one of them runs 4 times per day out to 384 hours and the other runs twice a day to 240 hours. If the Euro ran the same amount as the GFS, we may see similar results.

[jlauderdal]

You can download, upload to an image site, and post.

930 in the bahamas will get peoples attention

High Cat 4 or low-end Cat 5? Better pull a Joaquin and recyrve real quick.

wont happen if that ridge to the north remains in that model

[gatorcane]

long-range CMC ensembles are into the Bahamas then Florida in the long-range: