ATL: DORIAN - Models

[chaser1]

Key takeaway is anymore northward shifts in the GFS and Euro that avoid Hispaniola and watch out. It does not look like dry air nor shear will be significant enough alone to disrupt in the Caribbean and conditions in the Bahamas look very good.

Other key would be whether this apparent resurgent mid level ridging north of the Bahamas will time right with Dorian's approach. Now we start looking for a bit of increased model run after run consistency. Come tomorrow evening into Tuesday, it may be time to look a bit closer at the upper air forecasts (gas up the Gulfstream and get 'er on the tarmac)

[AJC3]

Heading WNW toward Palm Beach county it looks like? Just off shore as a TS

https://uploads.tapatalk-cdn.com/201908 ... 63c22d.png

High-res OP-ECM makes landfall around 06Z SUN, near Sewall's Point along the Martin/St. Lucie County line. This would be the same location that both Hurricanes Frances and Jeanne made landfall in 2004.

[sma10]

Heading WNW toward Palm Beach county it looks like? Just off shore as a TS

https://uploads.tapatalk-cdn.com/201908 ... 63c22d.png

High-res ECM makes landfall around 06Z SUN, near Sewall's Point along the Martin/St Lucie County line. This would be the same location that both Hurricanes Frances and Jeanne made landfall in 2004.

Yeah, a sucky trend going on here. Obviously strength from 6 days out is a crapshoot, forget the 1004mb. A trop cyclone given two days in the Bahamas under favorable conditions could turn out to be anything

[AJC3]

Heading WNW toward Palm Beach county it looks like? Just off shore as a TS

https://uploads.tapatalk-cdn.com/201908 ... 63c22d.png

High-res OP-ECM makes landfall around 06Z SUN, near Sewall's Point along the Martin/St. Lucie County line. This would be the same location that both Hurricanes Frances and Jeanne made landfall in 2004.

Yeah, a sucky trend going on here. Obviously strength from 6 days out is a crapshoot, forget the 1004mb. A trop cyclone given two days in the Bahamas under favorable conditions could turn out to be anything

Exactly. The upper tropospheric shear looks next to nil north of the GA, assuming that TUTT low gets out of the way fast enough. That's also a big assumption.

[chaser1]

Not sure if previously referenced but ICON appears on board with a similar intensification and track toward Southeast Florida. 12 Z had a much weaker impulse moving through the Fl. Straits but the 0Z is clearly much stronger. In the "for what it's worth column", the 18Z NAVGEM is very similar to the latest ICON run

[AJC3]

Heading WNW toward Palm Beach county it looks like? Just off shore as a TS

https://uploads.tapatalk-cdn.com/201908 ... 63c22d.png

High-res OP-ECM makes landfall around 06Z SUN, near Sewall's Point along the Martin/St. Lucie County line. This would be the same location that both Hurricanes Frances and Jeanne made landfall in 2004.

The next few ECM panels from 12Z SUN - 12Z MON show some significant northward trochoidal wobbles just before and after landfall - and eventually a northward turn through the eastern side of the Florida peninsula. Disquieting trend, but it's still 6+ days out so much is likely to change between now and then. Obviously, the interaction of Dorian with the TUTT low over the NE Caribbean and then the island of Hispanola will determine its eventual fate.

[Highteeld]

[Highteeld]

* ATLANTIC 2019 SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* DORIAN AL052019 08/26/19 06 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 50 54 58 63 66 73 75 78 77 76 76 77 79
V (KT) LAND 50 54 58 63 66 73 75 78 77 58 49 50 52
V (KT) LGEM 50 54 58 62 67 76 85 87 85 64 53 61 72
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 3 2 6 1 3 5 8 9 11 2 4 2 4
SHEAR ADJ (KT) 2 2 0 0 1 0 -1 2 -3 2 -5 -1 -3
SHEAR DIR 149 59 46 36 334 332 258 262 260 302 246 11 360
SST (C) 28.5 28.8 29.0 28.8 28.9 29.2 29.0 29.1 29.1 29.0 29.2 29.2 29.3
POT. INT. (KT) 144 149 152 149 151 156 152 154 153 152 155 154 155
ADJ. POT. INT. 144 149 152 149 151 155 150 149 145 143 144 141 139
200 MB T (C) -54.1 -54.2 -54.0 -53.9 -54.0 -53.9 -53.9 -53.8 -53.9 -54.0 -54.0 -54.1 -54.3
200 MB VXT (C) -0.1 -0.1 -0.1 -0.1 -0.1 -0.1 -0.2 -0.2 -0.2 -0.2 0.0 -0.2 -0.2
TH_E DEV (C) 10 10 11 11 10 12 11 12 12 12 12 11 11
700-500 MB RH 41 43 43 43 46 47 47 48 50 55 58 61 64
MODEL VTX (KT) 12 12 12 10 10 10 8 7 5 4 3 3 4
850 MB ENV VOR 8 9 11 2 0 9 14 13 2 -1 -24 -35 -70
200 MB DIV 5 0 -4 -8 15 22 17 28 -12 15 -1 21 8
700-850 TADV -2 0 0 0 2 1 2 2 6 8 5 7 3
LAND (KM) 558 469 372 296 275 389 320 145 54 -48 24 124 148
LAT (DEG N) 11.8 12.1 12.4 12.8 13.2 14.2 15.4 16.6 17.8 18.9 20.0 21.0 21.9
LONG(DEG W) 55.8 56.9 58.0 59.2 60.4 62.4 64.6 66.7 68.3 70.0 71.8 73.4 74.5
STM SPEED (KT) 12 11 12 12 12 12 12 11 10 10 9 8 6
HEAT CONTENT 33 47 54 39 38 47 44 73 86 67 49 50 54

FORECAST TRACK FROM OFCI INITIAL HEADING/SPEED (DEG/KT):280/ 12 CX,CY: -11/ 2
T-12 MAX WIND: 40 PRESSURE OF STEERING LEVEL (MB): 575 (MEAN=620)
GOES IR BRIGHTNESS TEMP. STD DEV. 50-200 KM RAD: 16.1 (MEAN=14.5)
% GOES IR PIXELS WITH T < -20 C 50-200 KM RAD: 30.0 (MEAN=65.0)
PRELIM RI PROB (DV .GE. 35 KT IN 36 HR): 23.0

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. 11. 12. 12.
SST POTENTIAL 1. 2. 3. 3. 5. 7. 11. 14. 16. 18. 20. 20.
VERTICAL SHEAR MAG 1. 2. 3. 4. 7. 8. 10. 11. 13. 14. 15. 16.
VERTICAL SHEAR ADJ 0. 0. 0. 0. 0. 1. 1. 1. 1. 2. 2. 2.
VERTICAL SHEAR DIR 0. 1. 1. 1. 2. 2. 1. 0. -1. -2. -2. -2.
PERSISTENCE 2. 2. 2. 2. 1. 1. 1. 1. 1. 0. 0. 0.
200/250 MB TEMP. 0. 0. 0. -1. 0. 0. 0. 0. 0. 0. 1. 1.
THETA_E EXCESS 0. 0. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1.
700-500 MB RH 0. 0. 1. 1. 1. 2. 2. 2. 2. 1. 1. 0.
MODEL VTX TENDENCY 0. 0. -1. -2. -3. -6. -8. -12. -15. -17. -18. -17.
850 MB ENV VORTICITY 0. 0. 0. 0. -1. -1. -1. -1. -1. -1. -2. -2.
200 MB DIVERGENCE 0. 0. -1. -1. -1. -1. -1. -1. -1. 0. 0. 1.
850-700 T ADVEC 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
ZONAL STORM MOTION 0. 0. 0. 0. 0. 1. 1. 1. 1. 2. 2. 2.
STEERING LEVEL PRES 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 1. 1.
DAYS FROM CLIM. PEAK 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
GOES PREDICTORS -1. -1. -1. -1. -1. -2. -2. -3. -3. -3. -3. -4.
OCEAN HEAT CONTENT 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.
RI POTENTIAL 1. 1. 3. 4. 5. 5. 3. 2. 0. -1. -2. -3.
----------------------------------------------------------
TOTAL CHANGE 4. 8. 13. 16. 23. 25. 28. 27. 26. 26. 27. 29.

CURRENT MAX WIND (KT): 50. LAT, LON: 11.8 55.8

** 2019 ATLANTIC RI INDEX AL052019 DORIAN 08/26/19 06 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) : 10.0 -49.5 to 33.0 0.72 12.0
850-200 MB SHEAR (KT) : 2.9 30.1 to 2.3 0.98 6.2
HEAT CONTENT (KJ/CM2) : 42.2 0.0 to 151.8 0.28 1.5
STD DEV OF IR BR TEMP : 16.1 36.6 to 2.8 0.61 4.1
MAXIMUM WIND (KT) : 50.0 22.5 to 137.5 0.74 2.7
2nd PC OF IR BR TEMP : 0.7 2.9 to -2.9 0.38 1.8
POT = MPI-VMAX (KT) : 99.1 27.5 to 139.6 0.64 2.8
D200 (10**7s-1) : 1.6 -29.7 to 185.9 0.15 0.3
%area of TPW <45 mm upshear : 36.2 100.0 to 0.0 0.64 0.0
BL DRY-AIR FLUX (W/M2) : 433.6 895.4 to -55.0 0.49 0.0

SHIPS Prob RI for 20kt/ 12hr RI threshold= 11% is 2.2 times climatological mean ( 5.2%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 44% is 4.0 times climatological mean (10.9%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 31% is 4.6 times climatological mean ( 6.9%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 20% is 5.4 times climatological mean ( 3.8%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 15% is 6.4 times climatological mean ( 2.4%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 41% is 9.1 times climatological mean ( 4.5%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 43% is 9.3 times climatological mean ( 4.6%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 39% is 7.3 times climatological mean ( 5.4%)

[galaxy401]

The recent models runs do show some attention now with Dorian potentially surviving the crossing and becoming a threat to Florida. I'm going to expect a lot more user activity tomorrow.

[TheProfessor]

Was fixing to fall asleep when I saw this on the latest update(please excuse my horribly drawn circle)

This is the Rapid Intensification aid, I don't know much about(there's a whole paper I just found that I need to read in the morning. But, the first time I saw this was in the midst of Harvey's explosion and again with Irma, it was quite the talk in our meteorology hangout when I was in school. Anyways, it shows up when the probabilities for RI are high enough. I've only ever seen RI25 and RI30(Which are both pretty crazy themselves.) but it goes up to RI40 for a 40 knot increase. Anyways, if this aid is correct then Dorian would be ahead of schedule wind wise than all the other models. It will be very interesting to watch.

[USTropics]

GFS ensemble trend over past 4 runs:

[USTropics]

00z UKMET animated run:

[USTropics]

00z position of operational models (GFS/ECMWF/UKMET/ICON) at 144 hours:

[Hammy]

00z position of operational models (GFS/ECMWF/UKMET/ICON) at 144 hours:
https://i.ibb.co/6Nz4FYh/Webp-net-gifmaker-7.gif

That's a pretty tight track consensus that far out.

[Kingarabian]

Through 144 hours, 00z EPS have 8 members showing 1004mb or lower pressures compared to 4 @ 12z.

[Kingarabian]

00z UKMET Ensembles:

[jlauderdal]

The recent models runs do show some attention now with Dorian potentially surviving the crossing and becoming a threat to Florida. I'm going to expect a lot more user activity tomorrow.

the interaction with Hispaniola is always tricky, it doesn't have to track directly over it to have inflow severely disrupted even if it splits the passage and a core stays intact. The flip side, we have seen systems go through there with limited disruption and get into the Bahamas/straits and do well.

[Nimbus]

The recent models runs do show some attention now with Dorian potentially surviving the crossing and becoming a threat to Florida. I'm going to expect a lot more user activity tomorrow.

the interaction with Hispaniola is always tricky, it doesn't have to track directly over it to have inflow severely disrupted even if it splits the passage and a core stays intact. The flip side, we have seen systems go through there with limited disruption and get into the Bahamas/straits and do well.

The 06Z legacy GFS shows a hurricane tracking further right than the other models so may not be effected by the high terrain. GFS ensemble had at least one member with a recurve.

The ridging remains in the 06Z run forcing a Florida landfall near the Cape.

[HurryKane]

12z ensemble spaghetti plots for ECMWF, GFS, and UKMET:

https://i.imgur.com/VRYaosG.gif

This is great, where do you source this gif from?

[toad strangler]

00z position of operational models (GFS/ECMWF/UKMET/ICON) at 144 hours:
https://i.ibb.co/6Nz4FYh/Webp-net-gifmaker-7.gif

That's a pretty tight track consensus that far out.

There is no consensus whatsoever. Each model is still significantly different each run.