ATL: GRACE - Remnants - Discussion

[jlauderdal]

Very interesting few days ahead for Grace as it does have hurdles in its way but the modeling has been so poor that if it can stay off the islands there are real possibilities regardless of the shear forecast, shear forecasts are as iffy as the hwrf. I'm off to the high mountains of colorado 9000+ with no intention of coming back early which means SE Florida is in the crosshairs for something big

[AlphaToOmega]

Tropical Storm Grace is moving 19 knots westward. I do not expected it to strengthen much over the next few days. The Gulf of Mexico seems like the most favorable place for intensification.

[HuracanMaster]

https://twitter.com/JohnConwaywx/status/1426465026836160512

...the intensity forecast
becomes somewhat complicated as the system is forecast to interact
with an upper-level trough while possibly crossing the Greater
Antilles at the same time. Slight weakening is indicated in the NHC
intensity forecast as the system crosses the northern portion of the
Dominican Republic early next week. Thereafter, moderate to strong
northerly shear is forecast to impact Grace as the system moves into
the flow on the western side of an upper-level trough over the
western Atlantic. This shear should prevent any further
strengthening through the end of the forecast period. The intensity
forecast is a little lower than a blend of the NOAA HCCA and IVCN
consensus, as there is likely a high bias from the HWRF in these
solutions. The latter portion of the NHC intensity forecast is of
lower-than-normal confidence due to the potential for a longer
amount of time over the rugged terrain of the Greater Antilles than
indicated, and also due to the fragile nature of the small cyclone
and the possible effects of the stronger shear later in the
forecast period.

Small cyclone that also are subject to sudden burst of intesity up and down. HWRF has me worried, 978 mb entering PR.

[Nimbus]

https://twitter.com/JohnConwaywx/status/1426465026836160512

...the intensity forecast
becomes somewhat complicated as the system is forecast to interact
with an upper-level trough while possibly crossing the Greater
Antilles at the same time. Slight weakening is indicated in the NHC
intensity forecast as the system crosses the northern portion of the
Dominican Republic early next week. Thereafter, moderate to strong
northerly shear is forecast to impact Grace as the system moves into
the flow on the western side of an upper-level trough over the
western Atlantic. This shear should prevent any further
strengthening through the end of the forecast period. The intensity
forecast is a little lower than a blend of the NOAA HCCA and IVCN
consensus, as there is likely a high bias from the HWRF in these
solutions. The latter portion of the NHC intensity forecast is of
lower-than-normal confidence due to the potential for a longer
amount of time over the rugged terrain of the Greater Antilles than
indicated, and also due to the fragile nature of the small cyclone
and the possible effects of the stronger shear later in the
forecast period.

Small cyclone that also are subject to sudden burst of intesity up and down. HWRF has me worried, 978 mb entering PR.

The first thing that popped into my head was my girlfriends cockatiel "foot" she bought from a retired CIA agent.
Might mean a more northerly track with the Mona Passage in play but that is just intuition.
NHC seems to think there might be more land interaction with Hispaniola.
Its avery nebulous walk through the forest at this point.

[aspen]

Quite blobby this morning, but convection is deep and healthy looking. Still have no idea when recon is supposed to get there.

[NDG]

Another tricky forecast ahead. I can see the NHC being very conveservative based on the two previous systems taking a similar track and atmospheric conditions.
But I keep saying one these days the HWRF is going to be right and bite us all

[AlphaToOmega]

The latest operational GFS run has Tropical Storm Grace as a 985-millibar hurricane making landfall around Tampa.

[gatorcane]

The latest operational GFS run has Tropical Storm Grace as a 985-millibar hurricane making landfall around Tampa.

Bearish GFS ensembles though, I posted an image in the models thread

[USVIKimmie]

I'm nowhere near a pro at this, but living with it in the USVI for close to 20 years, I've learned to trust my tools (and wxman57 ). There's a wind app that's eerily accurate and it's forecasting 45-60 for the station closest to me, and St Croix getting 30-40kts. This wavering from the NHC is similar to how they totally got Dorian wrong - it went Cat 1 in Charlotte Amalie harbor (had friends on boats registered 100+ on wind instruments). Gotta love Boat Life (not always)

[NDG]

Very important the Latitude where Grace's LLC is and determing whether it tracks over Hispaniola or not, which is its biggest obstacle, IMO.

[Yellow Evan]

TXNT22 KNES 141151
TCSNTL

A. 07L (GRACE)

B. 14/1130Z

C. 15.9N

D. 56.4W

E. THREE/GOES-E

F. T2.5/3.0

G. IR/EIR/VIS

H. REMARKS...CENTER IS EMBEDDED <1/3 DEG INTO A LARGE COLD OVC RESULTING
IN A DT OF 3.5. MET AND PT=2.5. SYSTEM APPEARS TO BE IMPACTED BY SOME
SHEAR DUE TO FAST FORWARD MOTION. FT IS BASED ON MET DUE TO
PULSING/IRREG CONVECTION.

I. ADDL POSITIONS

NIL


...KONON

Why is SAB not using DT lately?

[aspen]

Convection is very deep over the center (<-75C), and it seems like there’s some primitive banding on visible imagery. I think Grace is already stronger than forecast and might be closer to 45-50 kt by the time recon arrives later this afternoon.

[Yellow Evan]

Looks much better this morning with a defined curved band and a CDO. This development was not anticipated by models but given the low shear predicted it’s also not that much of a surprise.

[Woofde]

Grace certainly has the look of a healthy developing cyclone this morning. With little shear in the short term I could definitely see this ramping up pretty fast before PR. It's hard to believe we really have a 3rd storm that might dance with Hispaniola and it's only August 13th.

[SFLcane]

[InfernoFlameCat]

We could get a short RI phase here. Very good looking with deep organized convection and a prominent feeder band to its west.

[Hypercane_Kyle]

Looks decent, but we all know that doesn't always correlate with an organized system. What's under the hood is what matters.

[AlphaToOmega]

On the 06Z surface analysis, I see two circular isobars around Tropical Storm Grace. This is definitely healthy right now.

[InfernoFlameCat]

Looks decent, but we all know that doesn't always correlate with an organized system. What's under the hood is what matters.

https://i.imgur.com/uE3TuUC.jpg

The microwave pass showed an organized llc under the convection. I think she is at 50 knots

[aspen]

The 12z best track puts Grace’s LLC at 57.0W, a little east of the main convective blob, so it doesn’t seem to be fully lined-up with convection just yet. We’ll have to wait for recon this afternoon to truly know what it’s like under the hood.