WxWatcher007

Tropical Storm Henri Discussion Number 4 NWS National Hurricane Center Miami FL AL082021 500 PM AST Mon Aug 16 2021 Deep convection has persisted near and southeast of the center of the small tropical cyclone today, and subjective Dvorak intensity estimates were a consensus T2.5 (35 kt) at 1800 UTC. Objective estimates from ADT and SATCON also support tropical storm status, therefore the depression has been upgraded to a 35-kt tropical storm with this advisory. Henri (ahn-REE) becomes the eighth named storm of the 2021 Atlantic hurricane season. This is the fourth-earliest eighth storm on record with only 2020, 2005, and 1936 having the eighth-named storm form earlier in the season. Henri is located over warm waters, but is currently being affected by light to moderate northerly shear and dry mid-level air in the surrounding environment. Although these conditions are not overly conducive for strengthening, most of the intensity guidance supports gradual intensification over the next 24 to 48 hours. After that time, a significant increase in northeasterly upper-level winds is depicted by the global models over the system, which is likely to halt further strengthening. In fact, given the small size of Henri, it is likely to be more susceptible to the increase in shear, and it could weaken faster than indicated below. The HWRF remains more aggressive, but given the expected increase in shear, that solution still does not seem likely. The NHC intensity forecast is in best agreement with the LGEM model, and is slightly below the IVCN intensity consensus. The tropical storm is moving south-southwestward or 200/6 kt. Henri is forecast to move west-southwestward during the next 12-24 hours around the southeastern side of a mid-tropospheric high over the western Atlantic. After that time, Henri should turn westward as the ridge shifts eastward to the north of the tropical cyclone, and after 72 hours Henri is expected to approach the western extent of the ridge and should turn northward and then north-northeastward. The dynamical model guidance is in somewhat better agreement during the next 48-72 hours, but there remains some spread later in the period as to how sharp of northward turn occurs. The new NHC track forecast is similar to the previous advisory and lies near the center of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 16/2100Z 31.0N 62.9W 35 KT 40 MPH 12H 17/0600Z 30.5N 63.4W 40 KT 45 MPH 24H 17/1800Z 30.3N 64.2W 45 KT 50 MPH 36H 18/0600Z 30.2N 65.4W 50 KT 60 MPH 48H 18/1800Z 30.2N 66.9W 50 KT 60 MPH 60H 19/0600Z 30.3N 68.5W 50 KT 60 MPH 72H 19/1800Z 30.5N 69.9W 45 KT 50 MPH 96H 20/1800Z 31.8N 70.2W 45 KT 50 MPH 120H 21/1800Z 34.2N 68.4W 45 KT 50 MPH $$ Forecaster Brown

I blame lack of sleep lol

Yeah—I think smart money is on out to sea, but still worth a casual eye I suppose since Grace wants to drive toward the equator now

At least I was in the ballpark on my wind call (60-65mph). Not sure how the hell I ended up so far off on pressure though (1005mb).

It’s still incredible to me that we went from a possible S FL hit to possible Bay of Campeche hit in two days.

The latest VDM did show an eyewall developing but open to the south, and that presentation has eroded a bit recently on radar. Recon about to do a SE to NW pass.

Good call

06z Euro brings a fair amount of rain, especially for the western part of the subforum.

65kt FL winds showing up in the NE quadrant as recon attempts a NE to SW center pass.

True, but this is far more organized than the fleeting burst of organization we saw yesterday. Very interesting to watch on radar and recon.

VDM from recon. Product: Air Force Vortex Message (URNT12 KNHC)Transmitted: 16th day of the month at 12:40ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF96-5302Storm Name: GraceStorm Number & Year: 07 in 2021 (flight in the North Atlantic basin)Mission Number: 6Observation Number: 04 ( See all messages of this type for this mission. )A. Time of Center Fix: 16th day of the month at 12:09:40ZB. Center Fix Coordinates: 17.57N 70.82WB. Center Fix Location: 86 statute miles (139 km) to the SW (223°) from Santo Domingo, Dominican Republic.C. Minimum Height at Standard Level: 749m (2,457ft) at 925mbD. Minimum Sea Level Pressure: 1007mb (29.74 inHg) - ExtrapolatedE. Dropsonde Surface Wind at Center (Undecoded): NAF. Eye Character: Not AvailableG. Eye Shape: Not AvailableH. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 37kts (42.6mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 18 nautical miles (21 statute miles) to the ESE (106°) of center fix at 11:58:00ZJ. Maximum Flight Level Wind Inbound: From 158° at 38kts (From the SSE at 43.7mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 16 nautical miles (18 statute miles) to the ESE (108°) of center fix at 11:58:30ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 37kts (42.6mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 4 nautical miles to the W (261°) of center fix at 12:07:30ZN. Maximum Flight Level Wind Outbound: From 332° at 36kts (From the NNW at 41.4mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 12 nautical miles (14 statute miles) to the SW (229°) of center fix at 12:16:00ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 18°C (64°F) at a pressure alt. of 740m (2,428ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 762m (2,500ft)R. Dewpoint Temp (collected at same location as temp inside eye): 12°C (54°F)R. Sea Surface Temp (collected at same location as temp inside eye): Not AvailableS. Fix Determined By: Penetration, Radar, Wind, Pressure and TemperatureS. Fix Level: 925mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 2 nautical milesRemarks Section: Maximum Flight Level Wind: 38kts (~ 43.7mph) which was observed 16 nautical miles (18 statute miles) to the ESE (108°) from the flight level center at 11:58:30Z Sea Level Pressure Extrapolation From: 925mb

GFS might not be terribly far off given what we're seeing so far this morning. Very impressive pressure drop.

Fred is making a run at hurricane intensity Tropical Storm Fred Tropical Cyclone Update NWS National Hurricane Center Miami FL AL062021 730 AM CDT Mon Aug 16 2021 ...HURRICANE HUNTERS FIND FRED INTENSIFYING AND LOCATED A LITTLE FARTHER EAST... Data from an Air Force Reserve Hurricane Hunter aircraft indicate that Fred is intensifying this morning, and now has maximum sustained winds near 60 mph (95 km/h), with an estimated minimum central pressure of 993 mb (29.32 inches). Data from the aircraft and National Weather Service Doppler radar indicate that Fred is now moving toward the north at 10 mph (17 km/h). SUMMARY OF 730 AM CDT...1230 UTC...INFORMATION ---------------------------------------------- LOCATION...28.7N 85.6W ABOUT 80 MI...125 KM SSW OF APALACHICOLA FLORIDA MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...N OR 10 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...993 MB...29.32 INCHES $$ Forecaster Brennan/Pasch

Tropical Storm Fred Tropical Cyclone Update NWS National Hurricane Center Miami FL AL062021 730 AM CDT Mon Aug 16 2021 ...HURRICANE HUNTERS FIND FRED INTENSIFYING AND LOCATED A LITTLE FARTHER EAST... Data from an Air Force Reserve Hurricane Hunter aircraft indicate that Fred is intensifying this morning, and now has maximum sustained winds near 60 mph (95 km/h), with an estimated minimum central pressure of 993 mb (29.32 inches). Data from the aircraft and National Weather Service Doppler radar indicate that Fred is now moving toward the north at 10 mph (17 km/h). SUMMARY OF 730 AM CDT...1230 UTC...INFORMATION ---------------------------------------------- LOCATION...28.7N 85.6W ABOUT 80 MI...125 KM SSW OF APALACHICOLA FLORIDA MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...N OR 10 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...993 MB...29.32 INCHES $$ Forecaster Brennan/Pasch

First VDM. Next pass likely to be a NE to SW pass. Product: Air Force Vortex Message (URNT12 KNHC)Transmitted: 16th day of the month at 12:36ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5303Storm Name: FredStorm Number & Year: 06 in 2021 (flight in the North Atlantic basin)Mission Number: 15Observation Number: 02 ( See all messages of this type for this mission. )A. Time of Center Fix: 16th day of the month at 11:57:40ZB. Center Fix Coordinates: 28.72N 85.61WB. Center Fix Location: 101 statute miles (162 km) to the S (178°) from Panama City, FL, USA.C. Minimum Height at Standard Level: 622m (2,041ft) at 925mbD. Minimum Sea Level Pressure: 993mb (29.33 inHg) - ExtrapolatedE. Dropsonde Surface Wind at Center (Undecoded): NAF. Eye Character: Not AvailableG. Eye Shape: Not AvailableH. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 42kts (48.3mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 8 nautical miles to the SSW (194°) of center fix at 11:54:30ZJ. Maximum Flight Level Wind Inbound: From 350° at 49kts (From the N at 56.4mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 22 nautical miles (25 statute miles) to the SW (229°) of center fix at 11:49:30ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 46kts (52.9mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 8 nautical miles to the ESE (113°) of center fix at 12:03:00ZN. Maximum Flight Level Wind Outbound: From 201° at 55kts (From the SSW at 63.3mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 9 nautical miles to the ESE (116°) of center fix at 12:03:30ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 21°C (70°F) at a pressure alt. of 757m (2,484ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 27°C (81°F) at a pressure alt. of 770m (2,526ft)R. Dewpoint Temp (collected at same location as temp inside eye): 8°C (46°F)R. Sea Surface Temp (collected at same location as temp inside eye): Not AvailableS. Fix Determined By: Penetration, Radar, Wind, Pressure and TemperatureS. Fix Level: 925mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 2 nautical milesRemarks Section: Maximum Flight Level Wind: 55kts (~ 63.3mph) which was observed 9 nautical miles to the ESE (116°) from the flight level center at 12:03:30Z Sea Level Pressure Extrapolation From: 925mb Maximum Flight Level Temp: 27°C (81°F) which was observed 7 nautical miles to the S (183°) from the flight level center

Grace is looking a good bit better on recon so far this morning.

Paging @STILL N OF PIKE Future Henri looks good for some swells.

Very good point.

An impressive NW to SE pass by recon. 993.0mb extrapolated. Unflagged SFMR of 46kts.

Wow. This weekend might have been one of the most fascinating tracking periods I've seen in years. Today looks nothing like we thought it would just 48 hours ago. Above, you will see all three systems we're watching. Tropical Storm Fred near Florida, Tropical Depression Grace just south of DR/Haiti, and Tropical Depression Eight in the central Atlantic. Let's start with a look at the basin. For now, all three are situated in areas of light to moderate shear. That has allowed each to develop, though each have handled shear differently. Fred is likely organizing or intensifying on final approach, while Grace has failed to take advantage of a low shear environment to do the same. TD Eight has been steady state since developing quickly yesterday, but has managed to continue firing convection and morning visible shows the center trying to relocate under the convection. For each, SSTs and TCHP have not been an issue. Let's start with Fred, the most imminent threat to the US. Tropical Storm Fred After a near fatal encounter with DR/Haiti and Cuba, Fred is back from the dead and is continuing a theme that we saw last season: organizing/intensifying near the coast. While some reorganization was expected, the overall appearance we see this morning wasn't really thought to be a possibility until about 24 hours ago. In addition, this weekend we saw substantial track changes, with center reformations and stationary movements forcing track shifts from the west coast of Florida to the Florida state line, and back toward the Panhandle. These shifts are highly unusual IMO, especially within 24-48 hours. Although Fred is expected to weaken quickly after landfall later on Monday, the uptick in organization, and eastward shift, has potential implications downstream. As it gets absorbed by a trough, that will bring flooding rains to the SE and potentially heavy rains further north. I'm not entirely sure the rainfall distribution will carry that deep inland, but it is certainly something to watch given the recent flash flooding in this region. In the end, Fred has become a respectable tropical cyclone. The same is looking increasingly possible for Grace, which to date has been the "dud" of the season. Tropical Depression Grace Grace has failed to meet virtually all expectations so far, and it is easy to see why, at least with regard to intensity. The early morning IR once again finds Grace to be disorganized, even in the face of relatively light shear. What could have been an intensifying system heading into DR/Haiti is a mess, with an elongated LLC that took days to develop, disorganized convection, and little indication that anything is changing. This, however, has caused truly massive changes in the track forecast and makes both intensity and track forecasts moving forward low confidence. This was the track for Grace at 5am on Saturday. ...and here it is this morning...with additional changes likely... Between Grace being far weaker than anticipated and the massive Atlantic ridge not providing the weakness (thus far) to turn Grace on a more WNW heading, Grace is increasingly likely to miss the Greater Antilles altogether. What that could mean is a more favorable environment for organization, but the presence of shear is possible as well. This leads to the final area of interest: Tropical Depression Eight. Tropical Depression Eight TD 8 burst onto the scene as an area with 20% odds to develop into a tropical cyclone at 8pm on Saturday. By 11pm on Sunday it was our 8th tropical cyclone of the season. This one has been a bit of a surprise, though it should be noted the guidance did have a signal for something to develop. Normally, this wouldn't be anything for the US to even give a second thought, but let's recall the theme of the season so far: anomalously strong ridging. TD 8, although far off the US coast, is in a warm SST and relatively low shear environment (though you can clearly see the impact of shear here) and it has the influence of a strong ridge nearby. The result? A little more uncertainty than we'd normally see. Some of the guidance, led by the Euro/EPS, wants to show a closer approach by what should become Tropical Storm Henri. Now, that's an outlier at the moment IMO, as the general ideal would be that TD 8 makes a complete clockwise turn around the ridge and heads harmlessly out to sea. However, if the ridge is stronger than anticipated and/or TD 8 becomes a deeper system and more able to be steered by the strong westward flow that in part is keeping Grace on this unexpected westward heading, it could be come an East Coast threat. You see this on a few of the EPS ensemble members. Emphasis on few. I think the smart money is on TD 8 never getting particularly close to the US, but given the anomalous ridging, and favorable environment for at least the next 24 hours to intensify, this might be something to watch if it becomes stronger than anticipated. We haven't reached August 20 yet, and the basin is about as hot as it can get. Indications are that the favorable window will remain open for the foreseeable future, further enhanced by the climatological peak of the season. Buckle up, folks. We're just getting started.

Stand by for a long tropical post

It looks like Fred is making an attempt at organizing/intensifying once again. Radar out of northern Florida shows the center once again trying to wrap convection around and increased velocities around the apparent center. IR shows what seems to be Fred's best appearance yet. If the center can stay under the convection and the convection wrap around, this could make a run at a minimal hurricane. Either way, this is likely to be a big rainmaker for a good part of the region.

What an incredible turn of events in the last 48 hours for Grace. When the weekend started I never imagined I'd be starting my Monday looking at a potential Mexico landfall and Grace avoiding virtually all land until then.

@GaWx this one is a little more interesting this morning, right? For now at least? I took a look at the EPS and there were certainly a few interesting members. Looks like most go OTS, but with a stronger system perhaps we get a further west push. NHC has really highlighted how uncertain a forecast this one is at D4 & D5. In fact, looking deeper at the EPS, the ones that do develop TD 8 do make it more of an EC threat. Interesting.

Yep--looks like the center got shunted a little SW per the VDM