WxWatcher007

Only recon is going to be able to confirm that. IR and recon look increasingly good though for future intensification.

599 WTNT43 KNHC 202042 TCDAT3 Tropical Storm Henri Discussion Number 20 NWS National Hurricane Center Miami FL AL082021 500 PM EDT Fri Aug 20 2021 Henri appears to be slowly gaining strength. Deep convection has been increasing during the past few hours and the upper-level outflow continues to become better established on the east side of the circulation. However, the low-level center is still located near the northwestern edge of the deep convection due to ongoing northerly wind shear. An ASCAT-B pass from a few hours ago showed peak winds of around 55 kt, with the strongest winds on the southeast side of the circulation. Based on this data, the initial intensity is set at 60 kt. An Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate Henri again this evening and the data the plane collects will be very helpful in estimating the storm's strength and structure. The tropical storm appears to be making the advertised turn to the right, with the latest initial motion estimated to be 335/6 kt. A trough over the central Appalachians is expected to cut off tonight, and the combination of that feature and a building ridge to the east/northeast of Henri should cause the storm to accelerate to the north on Saturday. The latest model runs have generally trended to the left again and are a bit faster, with most showing landfall in about 48 hours. Most of the models now show a slight left turn before landfall as Henri gets caught in the circulation of the aforementioned trough. The latest GFS and ECMWF ensemble members continue to span a region from near New York City to Cape Cod for the landfall point. Based on the latest consensus aids, the official track forecast has again been nudged to the west of the previous one and shows landfall occurring on Sunday. After day 3, Henri is forecast to eject northeastward. The ongoing northerly shear is expected to decrease tonight, and the global models show a favorable upper-level wind pattern developing over the storm through the weekend. These more conducive atmospheric conditions combined with the warm Gulf Stream waters should allow Henri to strengthen to a hurricane tonight or early Saturday, with additional intensification expected into Saturday night. By early Sunday, however, Henri is forecast to cross the north wall of the Gulf Stream, and that should end its opportunity for strengthening. Although steady to rapid weakening is forecast while Henri moves over cooler waters south of Long Island and New England, it will likely still be at or very near hurricane intensity when it reaches the coast. Post-tropical transition is forecast to occur by day 3 and the system should dissipate in 4 or 5 days. Users are reminded to not focus on the exact forecast of the center of Henri since impacts will extend far from the center. Key Messages: 1. Dangerous storm surge inundation is expected to begin Sunday in portions of Long Island, Connecticut, Rhode Island, and southeastern Massachusetts, where a Storm Surge Warning has been issued. Dangerous storm surge is possible beginning Sunday in western portions of Long Island and Connecticut in the Storm Surge Watch area. Residents in these areas should follow any advice given by local officials. 2. Hurricane conditions are expected to begin Sunday in portions of Long Island and Connecticut, where a Hurricane Warning has been issued. Hurricane conditions are possible Sunday across portions of Rhode Island and southeastern Massachusetts. 3. Heavy rainfall may lead to considerable flash, urban, and small stream flooding, along with the potential for widespread minor and isolated moderate river flooding, over portions of Long Island and New England Sunday into Monday. 4. Swells from Henri will continue to affect much of the east coast of the U.S. through the weekend. These swells could cause life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 20/2100Z 31.2N 73.9W 60 KT 70 MPH 12H 21/0600Z 32.8N 73.3W 65 KT 75 MPH 24H 21/1800Z 35.8N 72.3W 75 KT 85 MPH 36H 22/0600Z 38.9N 71.9W 75 KT 85 MPH 48H 22/1800Z 40.8N 72.4W 65 KT 75 MPH 60H 23/0600Z 42.0N 72.8W 45 KT 50 MPH...INLAND 72H 23/1800Z 42.9N 72.6W 30 KT 35 MPH...POST-TROPICAL 96H 24/1800Z 43.8N 68.9W 25 KT 30 MPH...POST-TROPICAL 120H 25/1800Z...DISSIPATED $$ Forecaster Cangialosi

There’s no reason to change any thoughts about intensity right now. This is a 70mph TS and even modest intensification would bring it near the NHC forecast. Don’t be a prisoner of the moment.

Microwave images here: https://www.nrlmry.navy.mil/htdocs_dyn_pregen_sat/PUBLIC/tc_pages/pages/tc21/ATL/08L.HENRI/ssmi/track_vis/thumb/Latest.html

The recon flight is high level so no structure analysis to come..

Yeah—still time and the guidance favors tomorrow more than today, but the clock is ticking and organization takes time, even in a favorable environment. Very helpful, thanks. Play it up. Preparedness over everything else for this one. Even with questions over the wind potential, we know coastal flooding could be significant and the flash flood risk is elevated, especially in central & eastern CT. With a track between New Haven and Westerly, RI this looks high impact to me even if winds are more meh IMO.

What’s the general reduction from 925 to surface in a decently mixed environment?

Recon is en route for the next mission, but microwave imagery suggests northerly shear still has Henri quite tilted. It may very well be a hurricane as a result of the convective bursting, but you won’t get big intensification until it becomes more aligned vertically.

Also—it’s August 20! We’re now in the run up to the peak. This season is far from over…

Not necessarily. You can have an inner core with gradual intensification or steady state. For a higher end hurricane you do need an inner core (and by inner core I mean a vertically aligned and fully closed eye) for rapid intensification. FWIW, SHIPS has a relatively low risk for RI in its latest forecast.

That's one heck of a hit for CT verbatim. 55-60kt 925mb winds across 2/3 of the state along with big rains.

As currently modeled it'd be the slowest hurricane to strike NE in recorded history. A lot of hydro concerns.

06z EPS

Still finding it south of the forecast points

Agree, there may be a balancing act here because although the SSTs and upwelling will promote weakening, the upper level divergence and lack of shear could allow for more steady state or gradual weakening than currently anticipated. We also don't know for sure how fast this will be moving or slowing up toward our latitude. All those things can make a tangible difference. The other thing is even though the wind field will be smaller, I do think some higher end winds (50-60 gusts) will be possible inland depending on distance to center. With saturated soils and fully leafed trees it won't take much to cause significant issues. Not right now. There's not enough evidence of a hurricane yet IMO. If it can develop a good inner core today it could really take off as shear drops and it gets ventilated even better than it already is. Intensity can really throw curveballs. Still think strong TS/low end cat 1 is most likely, but if Henri can rapidly intensify and become a strong hurricane further south, we might need to elevate the ceiling a little.

Seeing more 60-64kt FL winds on the east side of Henri. Recon should be turning for a NE to SW pass shortly.

North of the Gulf Stream? It's warm, but not high octane stuff. It's more timing though. The environment for quick intensification looks better to me a little further south.

Latest dropsonde. Need to see more to make sure it's actually representative of the wind field but this would have it close to hurricane status. Product: Air Force Temp Drop (Dropsonde) Message (UZNT13 KNHC)Transmitted: 20th day of the month at 12:14ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5304Storm Name: HenriStorm Number: 08 (flight in the North Atlantic basin)Mission Number: 4Observation Number: 07 ( See all messages of this type for this mission. )Part A... Date: Near the closest hour of 12Z on the 20th day of the month Highest Mandatory Level For Which Wind Was Reported: 925mb Coordinates: 29.3N 73.1W Location: 394 statute miles (634 km) to the NE (42°) from Nassau, Bahamas. Marsden Square: 080 ( About ) Surface and Standard Isobaric Surfaces Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed 1006mb (29.71 inHg) Surface (Sea Level) 23.4°C (74.1°F) 21.9°C (71°F) 190° (from the S) 63 knots (72 mph) 1000mb 54m (177 ft) 22.6°C (72.7°F) 21.3°C (70°F) 190° (from the S) 64 knots (74 mph) 925mb 734m (2,408 ft) 21.0°C (69.8°F) 19.9°C (68°F) 210° (from the SSW) 66 knots (76 mph) 850mb 1,464m (4,803 ft) 17.6°C (63.7°F) 17.1°C (63°F) No Wind Report Available For This Level Information About Radiosonde: - Launch Time: 11:54Z - About Sonde: A descending radiosonde tracked automatically by satellite navigation with no solar or infrared correction. Remarks Section... Dropsonde Location: Dropped in maximum wind band. Highest altitude where wind was reported: - Location: 29.31N 73.06W - Time: 11:54:31Z Lowest altitude where wind was reported: - Location: 29.34N 73.04W - Time: 11:56:50Z Mean Boundary Level Wind (mean wind in the lowest 500 geopotential meters of the sounding): - Wind Direction: 195° (from the SSW) - Wind Speed: 67 knots (77 mph) Deep Layer Mean Wind (average wind over the depth of the sounding): - Wind Direction: 210° (from the SSW) - Wind Speed: 60 knots (69 mph) - Depth of Sounding: From 844mb to 1006mb Average Wind Over Lowest Available 150 geopotential meters (gpm) of the sounding: - Lowest 150m: 155 gpm - 5 gpm (509 geo. feet - 16 geo. feet) - Wind Direction: 190° (from the S) - Wind Speed: 65 knots (75 mph) Sounding Software Version: AEV 30404 Part B: Data for Significant Levels... Significant Temperature And Relative Humidity Levels Level Air Temperature Dew Point 1006mb (Surface) 23.4°C (74.1°F) 21.9°C (71°F) 979mb 21.0°C (69.8°F) 19.7°C (67°F) 951mb 22.6°C (72.7°F) 19.8°C (68°F) 850mb 17.6°C (63.7°F) 17.1°C (63°F) Significant Wind Levels Level Wind Direction Wind Speed 1006mb (Surface) 190° (from the S) 63 knots (72 mph) 997mb 190° (from the S) 64 knots (74 mph) 985mb 195° (from the SSW) 71 knots (82 mph) 951mb 200° (from the SSW) 64 knots (74 mph) 933mb 210° (from the SSW) 63 knots (72 mph) 927mb 210° (from the SSW) 67 knots (77 mph) 920mb 215° (from the SW) 62 knots (71 mph) 911mb 215° (from the SW) 64 knots (74 mph) 900mb 215° (from the SW) 57 knots (66 mph) 886mb 225° (from the SW) 61 knots (70 mph) 860mb 235° (from the SW) 52 knots (60 mph) 855mb 240° (from the WSW) 56 knots (64 mph)

We’re on the cusp of a historic event

Corrected VDM Product: Air Force Vortex Message (URNT12 KNHC)Corrected: This observation corrected a previously corrected observation.Transmitted: 20th day of the month at 12:06ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5304Storm Name: HenriStorm Number & Year: 08 in 2021 (flight in the North Atlantic basin)Mission Number: 4Observation Number: 05 ( See all messages of this type for this mission. )A. Time of Center Fix: 20th day of the month at 11:41:10ZB. Center Fix Coordinates: 29.87N 73.65WB. Center Fix Location: 388 statute miles (624 km) to the SSE (164°) from Cape Hatteras, NC, USA.C. Minimum Height at Standard Level: 1,439m (4,721ft) at 850mbD. Minimum Sea Level Pressure: 1000mb (29.53 inHg)E. Dropsonde Surface Wind at Center: From 275° at 33kts (From the W at 38mph)F. 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: 54 nautical miles (62 statute miles) to the N (351°) of center fix at 11:24:00ZJ. Maximum Flight Level Wind Inbound: From 85° at 43kts (From the E at 49.5mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 66 nautical miles (76 statute miles) to the NNW/N (349°) of center fix at 11:20:00ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 59kts (67.9mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 47 nautical miles (54 statute miles) to the SE (134°) of center fix at 11:55:00ZN. Maximum Flight Level Wind Outbound: From 240° at 62kts (From the WSW at 71.3mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 45 nautical miles (52 statute miles) to the SE (134°) of center fix at 11:54:30ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 19°C (66°F) at a pressure alt. of 1,523m (4,997ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 24°C (75°F) at a pressure alt. of 1,520m (4,987ft)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, Wind, Pressure and TemperatureS. Fix Level: 850mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 1 nautical mileRemarks Section: Maximum Flight Level Wind: 62kts (~ 71.3mph) which was observed 45 nautical miles (52 statute miles) to the SE (134°) from the flight level center at 11:54:30Z

Recon is going through some of the convection so keep that in mind, but Henri looks robust. Small area with 55-62kt FL winds and unflagged 58-59kt SFMR.

Seems odd to me that it has intensification north of NC.

Per the overlays, it looks like the center of Henri is just west of the deepest convection.

I think so too. Maybe not central LI yet, but I don't think the trend west is quite done yet. This one also had much shorter lead time. Usually we're tracking a CV for 10 days or so before landfall. Just a few days ago we were arguing whether this was even worth talking about lol.

998.5 mb extrapolated by recon at ~5k ft.