WxWatcher007

Another ratter en route

Recon approaching the center again for a NE to SW pass.

A number of interesting nuggets in that discussion.

Latest VDM Product: Air Force Vortex Message (URNT12 KNHC)Transmitted: 8th day of the month at 1:56ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5306Storm Name: LeeStorm Number & Year: 13 in 2023 (flight in the North Atlantic basin)Mission Number: 2Observation Number: 12 ( See all messages of this type for this mission. )A. Time of Center Fix: 8th day of the month at 1:28:50ZB. Center Fix Coordinates: 17.12N 52.18WB. Center Fix Location: 568 statute miles (913 km) to the ENE (61°) from Bridgetown, Barbados.C. Minimum Height at Standard Level: 2,538m (8,327ft) at 700mbD. Minimum Sea Level Pressure: 930mb (27.47 inHg)E. Dropsonde Surface Wind at Center: From 355° at 20kts (From the N at 23mph)F. Eye Character: ClosedG. Eye Shape & Diameter: Circular with a diameter of 15 nautical miles (17 statute miles)H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 143kts (164.6mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 6 nautical miles to the N (5°) of center fix at 1:27:00ZJ. Maximum Flight Level Wind Inbound: From 48° at 145kts (From the NE at 166.9mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 9 nautical miles to the NNW (343°) of center fix at 1:25:30ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 123kts (141.5mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 8 nautical miles to the SE (139°) of center fix at 1:31:00ZN. Maximum Flight Level Wind Outbound: From 252° at 124kts (From the WSW at 142.7mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 8 nautical miles to the SE (139°) of center fix at 1:31:00ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 7°C (45°F) at a pressure alt. of 3,056m (10,026ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 27°C (81°F) at a pressure alt. of 3,024m (9,921ft)R. Dewpoint Temp (collected at same location as temp inside eye): 4°C (39°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: 700mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 1 nautical mileRemarks Section: Maximum Flight Level Wind: 148kts (~ 170.3mph) which was observed 9 nautical miles to the ENE (64°) from the flight level center at 23:38:00Z

The SFMR might be questionable though. We see this in these higher end storms at times and the NHC hedges lower. I think this is around 140kt right now.

A worthwhile thread

SE eyewall with more standard FL and SFMR around 124 & 123kts respectively.

It's absolutely a 5 IMO

Agree. I think this one is right around 140kts based on other obs so far.

Peak FL winds of 144 & 145kts, with a peak SFMR of 143, 152, and 157kts. Insane.

Another big time pass. Peak FL winds of 144 & 145kts, with a peak SFMR of 143, 152, and 157kts. Extremely tight core.

Recon moving toward a NW to SE pass

May be a wash with Margot to the east. I think @CoastalWx mentioned that the models account for that though. A turn before 70W has been one of the most consistent forecasts across guidance. They'd all need to be underdoing the ridge for a much later turn, which is possible but unlikely IMO.

Every degree matters for an impact in the region. Shame that it looks like the environmental sampling mission never got done.

I think it's more instructive to use the super ensemble given the split in the GEFS/EPS, and just the fact that those individual members are pushing so far out in time they're not reliable IMO--whether they show land impacts or OTS. You can see in the plot below how confidence drops off rapidly at the latitude of Bermuda.

More instructive to use the super ensemble IMO, especially given the split between the GEFS and EPS.

NE eyewall dropsonde Product: Air Force Temp Drop (Dropsonde) Message (UZNT13 KNHC)Transmitted: 8th day of the month at 0:18ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5306Storm Name: LeeStorm Number: 13 (flight in the North Atlantic basin)Mission Number: 2Observation Number: 08Part A... Date: Near the closest hour of 0Z on the 8th day of the month Highest Mandatory Level For Which Wind Was Reported: 850mb Coordinates: 17.0N 51.6W Location: 598 statute miles (962 km) to the ENE (63°) from Bridgetown, Barbados. Marsden Square: 042 ( About ) Surface and Standard Isobaric Surfaces Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed 1000mb This level does not exist in this area of the storm above the surface level. 944mb (27.88 inHg) Surface (Sea Level) Unavailable 95° (from the E) 134 knots (154 mph) 925mb 177m (581 ft) 24.0°C (75.2°F) 24.0°C (75°F) 105° (from the ESE) 157 knots (181 mph) 850mb 918m (3,012 ft) 21.0°C (69.8°F) 21.0°C (70°F) 145° (from the SE) 159 knots (183 mph) 700mb 2,589m (8,494 ft) 14.8°C (58.6°F) 14.8°C (59°F) No Wind Report Available For This Level Information About Radiosonde: - Launch Time: 23:37Z - About Sonde: A descending radiosonde tracked automatically by satellite navigation with no solar or infrared correction. Remarks Section... Dropsonde Location: Dropped in eyewall 45° (NE) from the eye center. Highest altitude where wind was reported: - Location: 16.98N 51.59W - Time: 23:37:31Z Lowest altitude where wind was reported: - Location: 17.13N 51.68W - Time: 23:42:15Z Mean Boundary Level Wind (mean wind in the lowest 500 geopotential meters of the sounding): - Wind Direction: 110° (from the ESE) - Wind Speed: 158 knots (182 mph) Deep Layer Mean Wind (average wind over the depth of the sounding): - Wind Direction: 150° (from the SSE) - Wind Speed: 132 knots (152 mph) - Depth of Sounding: From 702mb to 944mb Average Wind Over Lowest Available 150 geopotential meters (gpm) of the sounding: - Lowest 150m: 149 gpm - -1 gpm (489 geo. feet - -3 geo. feet) - Wind Direction: 95° (from the E) - Wind Speed: 146 knots (168 mph) Sounding Software Version: AEV 30407 Part B: Data for Significant Levels... Significant Temperature And Relative Humidity Levels Level Air Temperature Dew Point 944mb (Surface) Unavailable 938mb 24.8°C (76.6°F) 24.8°C (77°F) 936mb 24.6°C (76.3°F) 23.5°C (74°F) 934mb 24.6°C (76.3°F) 24.6°C (76°F) 850mb 21.0°C (69.8°F) 21.0°C (70°F) Significant Wind Levels Level Wind Direction Wind Speed 944mb (Surface) 95° (from the E) 134 knots (154 mph) 943mb 95° (from the E) 135 knots (155 mph) 941mb 100° (from the E) 147 knots (169 mph) 939mb 95° (from the E) 152 knots (175 mph) 937mb 95° (from the E) 149 knots (171 mph) 934mb 95° (from the E) 154 knots (177 mph) 930mb 95° (from the E) 142 knots (163 mph) 924mb 110° (from the ESE) 162 knots (186 mph) 921mb 110° (from the ESE) 176 knots (203 mph) 918mb 115° (from the ESE) 180 knots (207 mph) 912mb 115° (from the ESE) 170 knots (196 mph) 908mb 115° (from the ESE) 168 knots (193 mph) 903mb 120° (from the ESE) 157 knots (181 mph) 897mb 125° (from the SE) 171 knots (197 mph) 885mb 140° (from the SE) 153 knots (176 mph) 875mb 140° (from the SE) 159 knots (183 mph) 867mb 145° (from the SE) 153 knots (176 mph) 858mb 145° (from the SE) 163 knots (188 mph) 850mb 145° (from the SE) 159 knots (183 mph) 841mb 145° (from the SE) 160 knots (184 mph) 829mb 155° (from the SSE) 134 knots (154 mph) 814mb 155° (from the SSE) 146 knots (168 mph) 702mb 190° (from the S) 126 knots (145 mph)

Looks like it still has time per recon obs on that first pass. The first VDM is wild. Product: Air Force Vortex Message (URNT12 KNHC)Transmitted: 8th day of the month at 0:04ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5306Storm Name: LeeStorm Number & Year: 13 in 2023 (flight in the North Atlantic basin)Mission Number: 2Observation Number: 06 ( See all messages of this type for this mission. )A. Time of Center Fix: 7th day of the month at 23:35:40ZB. Center Fix Coordinates: 16.94N 51.70WB. Center Fix Location: 590 statute miles (950 km) to the ENE (63°) from Bridgetown, Barbados.C. Minimum Height at Standard Level: 2,543m (8,343ft) at 700mbD. Minimum Sea Level Pressure: 936mb (27.64 inHg)E. Dropsonde Surface Wind at Center: From 220° at 34kts (From the SW at 39mph)F. Eye Character: ClosedG. Eye Shape & Diameter: Circular with a diameter of 15 nautical miles (17 statute miles)H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 139kts (160.0mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 6 nautical miles to the WSW (246°) of center fix at 23:33:30ZJ. Maximum Flight Level Wind Inbound: From 310° at 132kts (From the NW at 151.9mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 6 nautical miles to the WSW (246°) of center fix at 23:33:30ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 144kts (165.7mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 7 nautical miles to the ENE (70°) of center fix at 23:37:30ZN. Maximum Flight Level Wind Outbound: From 174° at 148kts (From the S at 170.3mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 9 nautical miles to the ENE (64°) of center fix at 23:38:00ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 9°C (48°F) at a pressure alt. of 3,044m (9,987ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 27°C (81°F) at a pressure alt. of 3,049m (10,003ft)R. Dewpoint Temp (collected at same location as temp inside eye): 10°C (50°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: 700mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 1 nautical mileRemarks Section: Maximum Flight Level Wind: 148kts (~ 170.3mph) which was observed 9 nautical miles to the ENE (64°) from the flight level center at 23:38:00Z

First VDM. So much good data here. Product: Air Force Vortex Message (URNT12 KNHC)Transmitted: 8th day of the month at 0:04ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5306Storm Name: LeeStorm Number & Year: 13 in 2023 (flight in the North Atlantic basin)Mission Number: 2Observation Number: 06 ( See all messages of this type for this mission. )A. Time of Center Fix: 7th day of the month at 23:35:40ZB. Center Fix Coordinates: 16.94N 51.70WB. Center Fix Location: 590 statute miles (950 km) to the ENE (63°) from Bridgetown, Barbados.C. Minimum Height at Standard Level: 2,543m (8,343ft) at 700mbD. Minimum Sea Level Pressure: 936mb (27.64 inHg)E. Dropsonde Surface Wind at Center: From 220° at 34kts (From the SW at 39mph)F. Eye Character: ClosedG. Eye Shape & Diameter: Circular with a diameter of 15 nautical miles (17 statute miles)H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 139kts (160.0mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 6 nautical miles to the WSW (246°) of center fix at 23:33:30ZJ. Maximum Flight Level Wind Inbound: From 310° at 132kts (From the NW at 151.9mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 6 nautical miles to the WSW (246°) of center fix at 23:33:30ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 144kts (165.7mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 7 nautical miles to the ENE (70°) of center fix at 23:37:30ZN. Maximum Flight Level Wind Outbound: From 174° at 148kts (From the S at 170.3mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 9 nautical miles to the ENE (64°) of center fix at 23:38:00ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 9°C (48°F) at a pressure alt. of 3,044m (9,987ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 27°C (81°F) at a pressure alt. of 3,049m (10,003ft)R. Dewpoint Temp (collected at same location as temp inside eye): 10°C (50°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: 700mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 1 nautical mileRemarks Section: Maximum Flight Level Wind: 148kts (~ 170.3mph) which was observed 9 nautical miles to the ENE (64°) from the flight level center at 23:38:00Z

Data from the eyewall was backfilled. Peak FL wind of 148kts and SFMR of 141kts. Very tight core as expected.

lol nothing from the NE eyewall.

Still waiting for the next set of obs...