ATL: IRMA - Models

[ColdMiser123]

Verbatim, weakness is right along the SE coast. Too early to say either way where this goes.

http://i.imgur.com/v0dcaSP.png

Agreed tough to say if the Bermuda High would build more west or the trough would build more east. Just too early to say. It's all long-range and the shifts are probably not over. The CMC and GFS recurve the system much earlier on so don't put the system in the same position the ECMWF has it.

We should get a better idea on what the European ensemble distribution is, relatively soon.

[blp]

So far this season, anything past 96 hours should be considered long range.

Amen to that statement. This year has been brutal. I remember Harvey getting buried into Mexico in run after run.

[KWT]

So far this season, anything past 96 hours should be considered long range.

Amen to that statement. This year has been brutal. I remember Harvey getting buried into Mexico in run after run.

Yeah, so many times the models were wrong with Harvey, to be fair the ECM was one of the first to clock that motion to the NE and then stall out.

[cycloneye]

* ATLANTIC SHIPS INTENSITY FORECAST *
* IR SAT DATA PROXY USED, OHC AVAILABLE *
* INVEST AL932017 08/28/17 18 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 25 26 27 29 33 41 50 56 63 69 73 80 82
V (KT) LAND 25 26 27 29 33 41 50 56 63 69 73 80 82
V (KT) LGEM 25 25 25 26 27 30 35 41 47 52 57 63 69
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 25 27 22 16 10 7 1 7 6 2 5 2 6
SHEAR ADJ (KT) -4 -2 -2 -2 -2 0 1 -1 -3 -1 0 -1 -2
SHEAR DIR 61 62 60 55 52 31 215 260 194 188 109 254 280
SST (C) 28.7 28.9 28.8 28.6 28.4 28.1 27.5 26.8 26.7 27.0 27.0 26.8 26.6
POT. INT. (KT) 147 150 148 145 142 138 131 123 122 124 122 121 119
ADJ. POT. INT. 147 148 145 142 137 133 126 116 115 115 111 111 109
200 MB T (C) -53.5 -53.5 -53.6 -53.6 -53.4 -54.0 -53.6 -53.9 -53.4 -53.9 -53.4 -53.6 -53.1
200 MB VXT (C) 0.1 0.1 0.1 0.1 0.1 0.1 0.0 0.1 0.1 0.1 0.2 0.3 0.4
TH_E DEV (C) 7 7 7 6 6 7 6 6 7 7 7 7 8
700-500 MB RH 75 76 77 78 80 78 73 64 56 55 55 54 49
MODEL VTX (KT) 12 12 11 12 13 12 14 14 15 17 16 18 18
850 MB ENV VOR 53 48 41 44 43 31 50 57 61 79 64 69 68
200 MB DIV 42 34 22 35 51 52 40 45 28 22 27 -1 -1
700-850 TADV -7 -9 -4 1 1 2 3 -1 0 0 3 3 1
LAND (KM) 511 587 636 702 766 924 1153 1413 1683 1928 2074 2144 2067
LAT (DEG N) 12.0 12.5 13.0 13.6 14.2 15.3 16.7 17.7 18.2 17.9 17.8 18.1 18.6
LONG(DEG W) 21.5 22.4 23.1 23.9 24.6 26.1 28.1 30.4 32.9 35.3 36.7 37.8 39.5
STM SPEED (KT) 11 9 9 9 9 10 12 12 12 9 5 7 8
HEAT CONTENT 8 10 13 21 28 22 16 4 2 5 12 14 11

FORECAST TRACK FROM TABM INITIAL HEADING/SPEED (DEG/KT):280/ 12 CX,CY: -11/ 2
T-12 MAX WIND: 25 PRESSURE OF STEERING LEVEL (MB): 464 (MEAN=618)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 19.9 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 44.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 55 KT IN 48 HR): 1.4

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 0. 0. 1. 2. 6. 12. 17. 21. 25. 27. 29. 30.
VERTICAL SHEAR MAG 0. 0. 0. 0. 2. 3. 4. 6. 7. 7. 8. 8.
VERTICAL SHEAR ADJ 0. 1. 1. 1. 2. 2. 3. 3. 4. 3. 3. 3.
VERTICAL SHEAR DIR 0. 1. 2. 3. 5. 6. 6. 5. 4. 5. 4. 4.
PERSISTENCE -0. -1. -1. -1. -1. -1. -1. -1. -0. 0. 0. 1.
200/250 MB TEMP. -0. -0. -1. -1. -1. -1. -1. -1. -1. -1. -0. 0.
THETA_E EXCESS -0. -0. -0. -0. -0. -1. -1. -1. -1. -2. -2. -2.
700-500 MB RH -0. -0. -1. -1. -2. -4. -5. -6. -6. -5. -5. -4.
MODEL VTX TENDENCY -0. -0. -0. 0. -1. 0. 0. 1. 2. 0. 2. 1.
850 MB ENV VORTICITY 0. 0. 0. 0. 0. 1. 1. 1. 1. 2. 2. 2.
200 MB DIVERGENCE 0. -0. -0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
850-700 T ADVEC 0. -0. -0. -0. -0. -0. -0. -1. -1. -1. -0. -0.
ZONAL STORM MOTION -0. 0. 0. 1. 1. 1. 1. 2. 2. 2. 2. 2.
STEERING LEVEL PRES 0. 0. 1. 1. 1. 1. 1. 2. 2. 1. 2. 1.
DAYS FROM CLIM. PEAK -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0. -0.
GOES PREDICTORS -0. -0. -0. -1. -2. -2. -3. -3. -3. -3. -2. -2.
OCEAN HEAT CONTENT -0. -0. -0. -0. -0. -1. -1. -1. -1. -1. -1. -0.
----------------------------------------------------------
TOTAL CHANGE 1. 2. 4. 8. 16. 25. 31. 38. 44. 48. 55. 57.

CURRENT MAX WIND (KT): 25. LAT, LON: 12.0 21.5

** 2017 ATLANTIC RI INDEX AL932017 INVEST 08/28/17 18 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): 0.0 -49.5 to 33.0 0.60 999.0
850-200 MB SHEAR (KT) : 20.0 30.1 to 2.9 0.37 999.0
HEAT CONTENT (KJ/cm2) : 16.0 0.0 to 156.2 0.10 999.0
2nd PC OF IR BR TEMP : 9999.0 2.4 to -3.0 999.00 999.0
STD DEV OF IR BR TEMP : 999.0 36.6 to 2.8 999.00 999.0
MAXIMUM WIND (kt) : 25.0 22.5 to 121.0 0.07 999.0
POT = MPI-VMAX (KT) : 118.7 28.4 to 139.6 0.81 999.0
D200 (10**7s-1) : 36.8 -29.7 to 181.5 0.31 999.0
BL DRY-AIR FLUX (w/m2): 43.0 961.4 to -67.1 0.89 999.0
% AREA WITH TPW <45 mm: 0.0 100.0 to 0.0 1.00 999.0

SHIPS Prob RI for 20kt/ 12hr RI threshold= 999% is 999.0 times sample mean ( 5.4%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 999% is 999.0 times sample mean (11.5%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 999% is 999.0 times sample mean ( 7.4%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 999% is 999.0 times sample mean ( 4.3%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 999% is 999.0 times sample mean ( 2.8%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 999% is 999.0 times sample mean ( 5.1%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 999% is 999.0 times sample mean ( 5.3%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 999% is 999.0 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: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0%
Logistic: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0%
Bayesian: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0%
Consensus: 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0% 999.0%

** PROBLTY OF AT LEAST 1 SCNDRY EYEWL FORMTN EVENT AL932017 INVEST 08/28/2017 18 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 26 27 29 33 41 50 56 63 69 73 80 82
18HR AGO 25 24 25 27 31 39 48 54 61 67 71 78 80
12HR AGO 25 22 21 23 27 35 44 50 57 63 67 74 76
6HR AGO 25 19 16 15 19 27 36 42 49 55 59 66 68
NOW CURRENT INTENSITY < 83 KT
IN 6HR INTENSITY IN 6HR < 83 KT
IN 12HR INTENSITY IN 12HR < 83 KT

[KWT]

As suspected the models tail off the strengthening from 96-120hrs due to a lowering of SSTs. If it stays a little south of where those models expect, this will take off quicker than the models are expecting at that point.

[AxaltaRacing24]

So far this season, anything past 96 hours should be considered long range.

Amen to that statement. This year has been brutal. I remember Harvey getting buried into Mexico in run after run.

Since the GFS almost always overdoes the troughing with these CV long trackers, its long range track does not make me feel comfortable just yet, especially with the euro showing a closer call.

[USTropics]

According to the GFS, there looks to be some slight dry air intrusion starting around 90 hours that could impede development (CMC shows a similar evolution in the PWAT anoms). Current SAL levels look drastically different then what we've seen so far this year in the MDR though, so maybe something can finally get going.

[Nimbus]

Verbatim, weakness is right along the SE coast. Too early to say either way where this goes.

So they have a trough very late in the early runs.
For a Cape Verde storm initialized that far south looks like a reasonable track.
I think Harvey was further north coming off Africa?

[AutoPenalti]

Remember about the positive NAO for this coming September.

[gatorcane]

Euro ensembles end generally east of the Bahamas and just north of Hispaniola/Puerto Rico in the long-range. Tough to tell what the individual ensembles show but there seems to be a spread. What is somewhat concerning is that they show the Western Atlantic ridge building westward in tandem with a trough over the Ohio river valley all in the long-range:

[hurricaneCW]

Definitely not a simple OTS call on this one, that huge Midwest trough is a big concern as its orientation could suck it in towards the coast.

If the mean trough was along the east coast, then I think we would be fine but this is all fantasy right now.

[WeatherEmperor]

Remember about the positive NAO for this coming September.

The majority of the little red forecast lines are to go back to negative NAO in early September. Looks like maybe 1 or 2 red lines show it positive. Lets see how this forecast changes in the coming days.


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[sma10]

Definitely not a simple OTS call on this one, that huge Midwest trough is a big concern as its orientation could suck it in towards the coast.

If the mean trough was along the east coast, then I think we would be fine but this is all fantasy right now.

Interesting, it's been so long since a Cape Verde tracker approached with the trough displaced to the Midwest, that I cannot even remember the last time it happened.

[CyclonicFury]

18z GFS coming in much weaker. Hope this isn't another 92L or 99L.

[AxaltaRacing24]

18z GFS coming in much weaker. Hope this isn't another 92L or 99L.

Still develops it decently but runs it to an ULL before hand due to faster movement. But will that lead to the GFS devastating one of east coast sates?

[SouthFLTropics]

Big difference between the GFS and the Euro in regards to the evolution of the trough and the ridge. Classic GFS vs. Euro battle potentially shaping up here.

[SouthFLTropics]

Hour 216, GFS vs. Euro

[RL3AO]

GFS has the trough south of Greenland in 8 days. Euro has it near Iceland. The later would allow 93L to move further west.

[SouthFLTropics]

GFS has the trough south of Greenland in 8 days. Euro has it near Iceland. The later would allow 93L to move further west.

You through me off there for a minute when you said Ireland initially!!!

[SouthFLTropics]

GFS vs. Euro, 240 Hours