ATL: GRACE - Remnants - Discussion

[wx98]

THAT RECON PASS

[ElectricStorm]

Holy crap that recon pass....

[galaxy401]

Very strong winds found on the NE there! Makes sense considering the eye is about to clear out.

Pressure hasn't responded yet though it looks like they missed it.

[Hypercane_Kyle]

Wow. Grace is actually just as strong as Karl in 2010 with several hours until landfall.

Current intensity is at least 100 knots with FL winds supporting that. Unreal rapid intensification.

[MarioProtVI]

Grace is the first major here since Karl 2010…holy moly taking a page right out of 2020

[aspen]

IR isn’t looking as impressive, and the pressure might have stabilized. Seems like Grace might be one of those storms that at first is intensifying near landfall, but then halts in the last several hours. Laura did the same thing last year, pausing at 936-940 mb and 125-130 kt in the last six hours before coming ashore.

Edit: okay we have a major. Holy moly that NE quad

Isn't that IR presentation normal for storms trying to clear an eye, from what I understand?

I think. Also, the steady pressure could be due to winds finally catching up with the 10+ mb pressure drop, and Grace might start deepening again.

Update: eyewall dropsonde has 115 kt near the surface

[Teban54]

Holy crap, 115 kt on that eyewall drop

Probably a gust, but still.

[Hypercane_Kyle]

Expecting a special advisory here soon. Gusts/FL winds support 105 knots.

[Hammy]

Expecting a special advisory here soon. Gusts/FL winds support 105 knots.

Regular advisory is in 30 minutes, I doubt they'd issue a special advisory this close.

[wx98]

Expecting a special advisory here soon. Gusts/FL winds support 105 knots.

No special advisory. It is time for the regular advisory.

[CrazyC83]

Expecting a special advisory here soon. Gusts/FL winds support 105 knots.

Regular advisory is in 30 minutes, I doubt they'd issue a special advisory this close.

They wouldn't ever put out a special advisory within 60-90 minutes of the scheduled regular advisory. If this was found right after the 4 pm advisory then yes a special would be warranted. The 10 pm advisory will likely confirm this and up the landfall intensity (maybe to cat 4).

[skyline385]

How does this even happen? The winds in the same NE quadrant went from 85 kts to 105 kts in the time recon completed 3 passes? Like what??

[ScottNAtlanta]

There was a dropsonde in the north section that came back 128kts at 925...didn't send back data for the surface. Thats only 680 feet up

[supercane4867]

Unlike Karl 2010, the large moisture envelope associated with Grace makes her less vulnerable to any continental dry air from the mountainous terrain of inland Mexico. Karl peaked 110kt offshore and barely maintained MH status at landfall whereas Grace will likely intensify until center crosses the coastline

[Homie J]

There was a dropsonde in the north section that came back 128kts at 925...didn't send back data for the surface. Thats only 680 feet up

Can you post this dropsonde

[Subtrop]

07L GRACE 210821 0000 20.7N 95.7W ATL 105 967

[Hypercane_Kyle]

Expecting a special advisory here soon. Gusts/FL winds support 105 knots.

Regular advisory is in 30 minutes, I doubt they'd issue a special advisory this close.

They wouldn't ever put out a special advisory within 60-90 minutes of the scheduled regular advisory. If this was found right after the 4 pm advisory then yes a special would be warranted. The 10 pm advisory will likely confirm this and up the landfall intensity (maybe to cat 4).

Woops, lost track of time and thought it was 9:30 PM Eastern.

[ScottNAtlanta]

There was a dropsonde in the north section that came back 128kts at 925...didn't send back data for the surface. Thats only 680 feet up

Can you post this dropsonde

Product: Air Force Temp Drop (Dropsonde) Message (UZNT13 KNHC)
Transmitted: 21st day of the month at 2:21Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF99-5309
Storm Name: Grace
Storm Number: 07 (flight in the North Atlantic basin)
Mission Number: 19
Observation Number: 16

Part A...

Date: Near the closest hour of 2Z on the 21st day of the month
Highest Mandatory Level For Which Wind Was Reported: 700mb
Coordinates: 20.9N 95.9W
Location: 160 statute miles (257 km) to the SE (127°) from Tampico, Tamaulipas, Mexico.
Marsden Square: 082

Surface and Standard Isobaric Surfaces
Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed
1000mb -171m (-561 ft) This level does not exist in this area of the storm above the surface level.
981mb (28.97 inHg) Surface (Sea Level) 24.0°C (75.2°F) 24.0°C (75°F) Unavailable
925mb 512m (1,680 ft) 20.8°C (69.4°F) 20.8°C (69°F) 105° (from the ESE) 128 knots (147 mph)
850mb 1,244m (4,081 ft) 18.2°C (64.8°F) 18.2°C (65°F) 130° (from the SE) 125 knots (144 mph)
700mb 2,908m (9,541 ft) 15.0°C (59.0°F) 12.3°C (54°F) 145° (from the SE) 82 knots (94 mph)

Information About Radiosonde:
- Launch Time: 2:02Z
- About Sonde: A descending radiosonde tracked automatically by satellite navigation with no solar or infrared correction.

[ScottNAtlanta]

Regular advisory is in 30 minutes, I doubt they'd issue a special advisory this close.

They wouldn't ever put out a special advisory within 60-90 minutes of the scheduled regular advisory. If this was found right after the 4 pm advisory then yes a special would be warranted. The 10 pm advisory will likely confirm this and up the landfall intensity (maybe to cat 4).

Woops, lost track of time and thought it was 9:30 PM Eastern.

4mins till 11pm advisories

[IcyTundra]

How many hours until landfall?