Personal forecast on Dolly

[Matt-hurricanewatcher]

[b]The posts in this forum are NOT official forecast 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.org. For official information, please refer to the NHC and NWS products.



Tropical storm Dolly
1pm pst/4pm est
7-20-2008


Winds 50 mph
Pressure 1008 millibars
movement northwestward 305 degrees at 12 knots
location 18.9/84.6


Tropical storm Dolly forms over the western Caribbean...


The distrabance we have tracked for over a week has developed into tropical storm Dollly, with the recon finally finding a closed LLC. The recon found 51 knot flight level winds, the LLC now appears to be tucked under the convection. So it is becoming slowly better organized.

The upper level environment is becoming "super favorable" with the upper ULL to the northwest backing away to the west, that should form a north or northwestward outflow jet. Shear levels are down over most of the system to now 5-8 knots, with 25-30 knot decreases over the last 24 hours. So you have a very good set up for tropical cyclone development and possible IRC's. This is very classic in if this pattern holds once into the Gulf this cyclone could strengthen very fast. The only limition on how strong this could get is the Yucatan, if it stays over it for to long it will lose its "inner" core. So that will force it to redevelop a new one. This was shown with Keith 2000, Emily 2005, and to the extreme Isidore 2002.


We have a high over the northern gulf of Mexico at 850 millibars that is forcing the steering flow to the west once pass 85 west. This high is even stronger as you go up through the Atmosphere, so any strengthing of the cyclone should also keep it on a westly path if the current set up where to hold. The hurricane models forecast a west-northwest track throughout the next 96-120 hours, taking it to around 24-26 north. The Gfs 12z shows that a weakness develops in this high around 72 hours, which forces it more northward. So a threat on southern Texas. The HWRF shows the system moving over the northern tip of the Yucatan only 18 hours from now. Followed by a westward motion to just south of the Border. NGP the same, with the Ukmet just south. The problem is they place the system about 60 nmi to far southward at the start. So a Mexico, Texas landfall Emily 2005 looks fairly likely. The models do went to weaken the high pressure to the north as a shortwave moves into the upper midwest around 60-72 hours, how strong will that be will be a factor in the track. The cluster of hurricane models show just south of the texas border, we will forecast for a brownsville landfall as of this time because the models are slightly south with placement.

Forecast
0 45 knots 18.9/84.6
6 45 knots 19.5/85.2
12 50 knots 19.9/85.9
24 55 knots 20.8/88.8
36 45 knots 21.9/91.8
48 65 knots 23.6/93.8
72 75 knots 25.3/95.2
96 85 knots 26.7/97.3 possible landfall over southern Texas
120 40 knots 27.5/103.2

[Matt-hurricanewatcher]

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast 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.org. For official information, please refer to the NHC and NWS products.

Tropical storm Dolly
10pm pst/1am est
7-21-2008


Winds 50 mph
Pressure 998 millibars
movement west 280 degree's 14 knots
Location 23.2/93.0

Bertha moving just north of west, expected to slowly strengthen.


Dolly is trying to form a "cdo" feature over the last few hours, with reds trying to develop. Recon also has found that the pressure is starting to fall, but as of the last plane has not found any strengthing in the winds. In fact weaker then the 50+ knot surface winds found earlier today. The cyclone is also moving westward...So chances of a Texas landfall has gone down. Tropical storm force winds over Texas is very possible still...

A upper ull we have been watching for the last few days is to the southwest of the cyclone; this is forcing midlevel shear, and hurting outflow south of the center. But latest recon data and satellite shows that this shear is becoming more favorable over the last hour or so. So the low levels and mid levels should finally stack over the next 6 hours. Once this happens the system should strengthen. Outflow out of the northern, northeastern quad is very very good at this moment in fact a northern outflow channel has developed, with the cyclone starting to draw its outflow from the BOC also instead of the BOC. Shear levels besides the southwestern quad are around 3-5 knots over the cyclone. So once the CDO develops we do expect this to become a hurricane. Also 85h data shows the first signs of a banding like eye...

Recon found that the system is moving just north of due west, so the ridge to the north is holding stronger then first thought on our first forecast. Which is normal for the models to do so. Steering flow maps from 500-850 millibars show that the core of the ridge to the north is moving eastward to centered on MS. The core of the shortwave is passing to the east. While a southern stream ULL has formed near 25 north/105 west flow near the coast from south to north. As the ridge breaks down this should help to turn this system more northwestward. The models are now south of Texas...In so we will forecast a track to around 40-60 nmi south of the Border.

We will forecast Dolly to become a 70 knot hurricane at around 24-30 hours, or just as it is moving onshore. There is still a outside chance this system could get into the more favorable environment close to the coast like Humberto.

Forecast
0 45 knots 23.2/93.0
6 50 knots 23.4/93.5
12 55 knots 23.8/94.6
24 65 knots 24.5/96.2
30 70 knots 25.2/97.2
36 55 knots 25.5/97.7 landfall