WxWatcher007

First pass from N to S has an extrapolated pressure of 973.9mb at about 10k ft. Awaiting dropsonde and sampling of southern portion of possible eyewall.

Looking at Cuba and now Key West radar you can see an increasingly organized system. That first recon pass and VDM will be very interesting.

Didn't add to the post, but recent microwave imagery suggests a nearly completed eyewall.

Recon is in the air and will soon provide critical structural and heading data on a strengthening Hurricane Idalia. Idalia has remained resilient in the face of moderate shear the last few days, gradually organizing and attempting to fire convection consistent enough to establish an inner core. This morning satellite and radar show that with shear decreasing Idalia is beginning to develop an inner core, with deep convection rotating around the center in the image above and an eye feature evident on radar. Recon will be important in assessing just how far along this inner core process has progressed, and whether there is still significant vortex tilting, which can still be possible if there's enough shear still present. My guess looking at the radar however, is that the vortex tilting that was an issue 24 hours ago is no longer enough to keep this from increasing its rate of intensification. According to CMISS analysis, shear is now in the favorable zone and expected to remain so until landfall. As the trough sets up during Idalia's final approach, upper diffluence combined with increasing OHC and SSTs will almost certainly allow for rapid intensification. (SST image courtesy of Brian McNoldy) Once rapid intensification occurs, and it is explicitly forecast by the NHC, we don't know where it'll stop. Time will be a limiting factor, but it cuts both ways. On on hand, there may not be enough time for the very high ceiling for Idalia to be reached. On the other, the lack of time means that a structural change, such as an Eyewall Replacement Cycle (ERC) is less likely. There is also modest but meaningful divergence in track. The consensus among most guidance is to bring this further north, while the European Model and stronger members of the EPS have a further east landfall. It's been talked about around here but we will need to watch for deviations closely, as there are almost always small changes that have a substantial impact on sensible weather. To be clear--nobody living in the region should merely look at the center track. Heavy rain, storm surge, and strong to destructive winds will be possible far outside the center. Given the parallel run up the west coast of Florida however, where the center landfalls is obviously important for surge and strongest wind impacts. The 06z GFS ticked ever so slightly east relative to 00z. Watch the organizational trends, pace of intensification, and the wobbles relative to long term heading. It should be an active day.

I think it shows what the absolute ceiling is should everything just take off between now and landfall, but it’s an outlier. I think it’s becoming extremely important as we get inside ~36 hours of landfall to analyze the structure and organizational pace of the system, and the inevitable wobbles that come with landfalling TCs. I like the NHC forecast and a landfall intensity between 105-115kt.

Which is surprising considering the GFS loves to spin up anything coming from a CAG. Completely missed the signal. Probably a nail biter to the end. Good thing is that the steady northward movement now should help smooth out any stall related hiccups we may have seen on track guidance. Agree. I don’t think we see a major shift at this point, but as the NHC says, the parallel movement up the west coast of Florida means any deviation has a major impact. Would not be surprised if this entered the Atlantic as a minimal hurricane if it comes into Florida south enough.

Mission 6 extrapolated down to 983.9mb but again, the caveat is that this was extrapolated at ~12,000ft. Nothing earth shattering about FL winds or SFMR so this is probably too low. Dropsonde would confirm. Stepping away for a bit unless there's something really interesting.

First VDM from mission 5. No eye observed at this time. Product: Air Force Vortex Message (URNT12 KNHC)Transmitted: 28th day of the month at 11:59ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF99-5309Storm Name: IdaliaStorm Number & Year: 10 in 2023 (flight in the North Atlantic basin)Mission Number: 5Observation Number: 05 ( See all messages of this type for this mission. )A. Time of Center Fix: 28th day of the month at 11:18:10ZB. Center Fix Coordinates: 20.61N 85.17WB. Center Fix Location: 115 statute miles (185 km) to the ESE (109°) from Cancún, Quintana Roo, Mexico.C. Minimum Height at Standard Level: 1,351m (4,432ft) at 850mbD. Minimum Sea Level Pressure: 990mb (29.24 inHg)E. Dropsonde Surface Wind at Center: From 125° at 12kts (From the SE at 14mph)F. Eye Character: Not AvailableG. Eye Shape: Not AvailableH. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 35kts (40.3mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 23 nautical miles (26 statute miles) to the WNW (300°) of center fix at 11:11:00ZJ. Maximum Flight Level Wind Inbound: From 24° at 37kts (From the NNE at 42.6mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 17 nautical miles (20 statute miles) to the WNW (294°) of center fix at 11:13:00ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 57kts (65.6mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 26 nautical miles (30 statute miles) to the SE (128°) of center fix at 11:27:00ZN. Maximum Flight Level Wind Outbound: From 191° at 56kts (From between the S and SSW at 64.4mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 59 nautical miles (68 statute miles) to the SE (132°) of center fix at 11:39:00ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 20°C (68°F) at a pressure alt. of 1,530m (5,020ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 22°C (72°F) at a pressure alt. of 1,530m (5,020ft)R. Dewpoint Temp (collected at same location as temp inside eye): 16°C (61°F)R. Sea Surface Temp (collected at same location as temp inside eye): Not AvailableS. Fix Determined By: Penetration, Wind and PressureS. Fix Level: 850mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 3 nautical milesRemarks Section: Maximum Flight Level Wind: 56kts (~ 64.4mph) which was observed 59 nautical miles (68 statute miles) to the SE (132°) from the flight level center at 11:39:00Z Maximum Flight Level Temp: 23°C (73°F) which was observed 11 nautical miles (13 statute miles) to the WNW (289°) from the flight level center

Mission 6 is doing a pass from N to S and has an extrapolated pressure so far of 985.1mb. The caveat here is that this is being extrapolated from an altitude of ~12,300ft. SFMR peak winds consistent with Mission 5 so far.

First major of the season is Franklin. WxWatcher007 Peak Season Forecast (Aug 20-Oct 20) Named Storms: 13 (5) Hurricanes: 6 (1) Major Hurricanes: 3 (1) Emily, Franklin (MH), Gert, Harold, Idalia

Hurricane Franklin Tropical Cyclone Update NWS National Hurricane Center Miami FL AL082023 735 AM EDT Mon Aug 28 2023 ...AIR FORCE HURRICANE HUNTERS FIND FRANKLIN TO BE STRONGER... Air Force Reserve Hurricane Hunter aircraft data indicate that Hurricane Franklin has strengthened this morning. The maximum winds are estimated to be 130 mph (210 km/h) with higher gusts. The minimum central pressure has dropped to 942 mb. The next full advisory on Franklin will be at 11AM EDT (1500 UTC). SUMMARY OF 735 AM...1135 UTC...INFORMATION ---------------------------------------------- LOCATION...27.4N 70.8W ABOUT 405 MI...650 KM N OF GRAND TURK ISLAND ABOUT 490 MI...790 KM SW OF BERMUDA MAXIMUM SUSTAINED WINDS...130 MPH...210 KM/H PRESENT MOVEMENT...NNW OR 335 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...942 MB...27.82 INCHES $$

Center dropsonde Product: Air Force Temp Drop (Dropsonde) Message (UZNT13 KNHC)Transmitted: 28th day of the month at 11:25ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF99-5309Storm Name: IdaliaStorm Number: 10 (flight in the North Atlantic basin)Mission Number: 5Observation Number: 06 ( See all messages of this type for this mission. )Part A... Date: Near the closest hour of 11Z on the 28th day of the month Highest Mandatory Level For Which Wind Was Reported: 850mb Coordinates: 20.6N 85.1W Location: 120 statute miles (193 km) to the ESE (109°) from Cancún, Quintana Roo, Mexico. Marsden Square: 081 ( About ) Surface and Standard Isobaric Surfaces Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed 1000mb -93m (-305 ft) This level does not exist in this area of the storm above the surface level. 990mb (29.24 inHg) Surface (Sea Level) 27.8°C (82.0°F) 25.7°C (78°F) 125° (from the SE) 12 knots (14 mph) 925mb 599m (1,965 ft) 24.4°C (75.9°F) 22.3°C (72°F) 150° (from the SSE) 9 knots (10 mph) 850mb 1,340m (4,396 ft) 21.2°C (70.2°F) 19.8°C (68°F) 150° (from the SSE) 8 knots (9 mph) Information About Radiosonde: - Launch Time: 11:18Z - About Sonde: A descending radiosonde tracked automatically by satellite navigation with no solar or infrared correction. Remarks Section... Dropsonde Location: Dropped in center. Highest altitude where wind was reported: - Location: 20.61N 85.14W - Time: 11:18:37Z Lowest altitude where wind was reported: - Location: 20.61N 85.14W - Time: 11:20:49Z Mean Boundary Level Wind (mean wind in the lowest 500 geopotential meters of the sounding): - Wind Direction: 130° (from the SE) - Wind Speed: 11 knots (13 mph) Deep Layer Mean Wind (average wind over the depth of the sounding): - Wind Direction: 140° (from the SE) - Wind Speed: 9 knots (10 mph) - Depth of Sounding: From 843mb to 989mb 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: 125° (from the SE) - Wind Speed: 13 knots (15 mph) Sounding Software Version: AEV 30407 Part B: Data for Significant Levels... Significant Temperature And Relative Humidity Levels Level Air Temperature Dew Point 990mb (Surface) 27.8°C (82.0°F) 25.7°C (78°F) 850mb 21.2°C (70.2°F) 19.8°C (68°F) Significant Wind Levels Level Wind Direction Wind Speed 990mb (Surface) 125° (from the SE) 12 knots (14 mph) 957mb 125° (from the SE) 10 knots (12 mph) 904mb 155° (from the SSE) 10 knots (12 mph) 854mb 140° (from the SE) 8 knots (9 mph) 843mb 165° (from the SSE) 8 knots (9 mph)

Mission 5 first pass produced an extrapolated pressure of 990.4mb. Peak FL wind of 50kt and unflagged peak SFMR of 55kt. Edit: basically confirms 5am intensity.

Mission 5 approaching the center to do a NW to SE pass. Getting a better sense of the wind field in each quadrant, as well as if there's a low level attempt at developing an eyewall is what I'm paying close attention to. It looks like it's trying again on radar, but recon will confirm. Idalia is clearly getting closer, however, and we're starting to see--for now at least--some convection to the north trying to wrap around.

Morning, everyone. There are going to be numerous missions at high and low altitude through landfall for Idalia now. The first morning low altitude flight is descending now. This is mission 5. An additional flight, mission 6, is starting to descend as well.

Always appreciate seeing your thoughts. Nice write up.

Yeah I mean as long as there are deep convective bursts like this it makes it more likely we see it wrap up. The hurricane models have had a good handle on its structure looking at 00z. It may take time, but a legitimate signal remains for a major hurricane. Latest dropsonde suggests that the pressures are lower than the extrapolated, and the first sonde about an hour ago, so it's moving along... Off to bed now. Night everyone. Product: Air Force Temp Drop (Dropsonde) Message (UZNT13 KNHC)Transmitted: 28th day of the month at 6:24ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5304Storm Name: IdaliaStorm Number: 10 (flight in the North Atlantic basin)Mission Number: 3Observation Number: 15 ( See all messages of this type for this mission. )Part A... Date: Near the closest hour of 6Z on the 28th day of the month Highest Mandatory Level For Which Wind Was Reported: 925mb Coordinates: 19.8N 85.2W Location: 143 statute miles (229 km) to the SE (131°) from Cancún, Quintana Roo, Mexico. Marsden Square: 045 ( About ) Surface and Standard Isobaric Surfaces Level Geo. Height Air Temp. Dew Point Wind Direction Wind Speed 1000mb -96m (-315 ft) This level does not exist in this area of the storm above the surface level. 989mb (29.21 inHg) Surface (Sea Level) 28.0°C (82.4°F) 26.4°C (80°F) 240° (from the WSW) 13 knots (15 mph) 925mb 597m (1,959 ft) 24.2°C (75.6°F) 23.6°C (74°F) 230° (from the SW) 11 knots (13 mph) 850mb 1,341m (4,400 ft) 24.4°C (75.9°F) About 17°C (63°F) No Wind Report Available For This Level Information About Radiosonde: - Launch Time: 6:19Z - About Sonde: A descending radiosonde tracked automatically by satellite navigation with no solar or infrared correction. Remarks Section... Dropsonde Location: Dropped in center. Highest altitude where wind was reported: - Location: 19.81N 85.19W - Time: 6:19:25Z Lowest altitude where wind was reported: - Location: 19.82N 85.19W - Time: 6:21:23Z Mean Boundary Level Wind (mean wind in the lowest 500 geopotential meters of the sounding): - Wind Direction: 230° (from the SW) - Wind Speed: 12 knots (14 mph) Deep Layer Mean Wind (average wind over the depth of the sounding): - Wind Direction: 230° (from the SW) - Wind Speed: 10 knots (12 mph) - Depth of Sounding: From 852mb to 989mb 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: 230° (from the SW) - Wind Speed: 12 knots (14 mph) Sounding Software Version: AEV 30407 Part B: Data for Significant Levels... Significant Temperature And Relative Humidity Levels Level Air Temperature Dew Point 989mb (Surface) 28.0°C (82.4°F) 26.4°C (80°F) 907mb 23.4°C (74.1°F) 23.2°C (74°F) 850mb 24.4°C (75.9°F) About 17°C (63°F) 843mb Unavailable Significant Wind Levels Level Wind Direction Wind Speed 989mb (Surface) 240° (from the WSW) 13 knots (15 mph) 980mb 230° (from the SW) 12 knots (14 mph) 928mb 225° (from the SW) 12 knots (14 mph) 887mb 240° (from the WSW) 10 knots (12 mph) 864mb 190° (from the S) 7 knots (8 mph) 852mb 280° (from the W) 1 knots (1 mph)

992.2mb extrapolated on the second pass. Peak FL of 53kts and SFMR of 47 & 48kts. Idalia has made a lot of progress in the last 24 hours in tightening up, but it's not there yet in terms of developing a nascent inner core. Not enough upshear thunderstorm activity is limiting intensification. For now.

Recon moving toward a NE to SW pass. Should get a lot of good info in the next 30 minutes or so.

1:00 AM CDT Mon Aug 28Location: 19.7°N 85.3°WMoving: StationaryMin pressure: 990 mbMax sustained: 60 mph

First VDM. Importantly, no evidence of an eye from recon. I'm interested in seeing what the wind field looks like (how symmetrical it is) and what the FL/SFMR are in the NE quad. Will also be telling if pressures fall in between center fixes. Product: Air Force Vortex Message (URNT12 KNHC)Transmitted: 28th day of the month at 5:28ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5304Storm Name: IdaliaStorm Number & Year: 10 in 2023 (flight in the North Atlantic basin)Mission Number: 3Observation Number: 08 ( See all messages of this type for this mission. )A. Time of Center Fix: 28th day of the month at 5:08:40ZB. Center Fix Coordinates: 19.72N 85.25WB. Center Fix Location: 144 statute miles (232 km) to the SE (134°) from Cancún, Quintana Roo, Mexico.C. Minimum Height at Standard Level: 1,363m (4,472ft) at 850mbD. Minimum Sea Level Pressure: 991mb (29.27 inHg)E. Dropsonde Surface Wind at Center: From 190° at 17kts (From the S at 20mph)F. Eye Character: Not AvailableG. Eye Shape: Not AvailableH. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 27kts (31.1mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 15 nautical miles (17 statute miles) to the NW (309°) of center fix at 5:03:30ZJ. Maximum Flight Level Wind Inbound: From 36° at 31kts (From the NE at 35.7mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 24 nautical miles (28 statute miles) to the NW (309°) of center fix at 5:01:00ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 54kts (62.1mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 17 nautical miles (20 statute miles) to the SE (134°) of center fix at 5:14:00ZN. Maximum Flight Level Wind Outbound: From 230° at 59kts (From the SW at 67.9mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 11 nautical miles (13 statute miles) to the SE (134°) of center fix at 5:12:00ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 26°C (79°F) at a pressure alt. of 1,532m (5,026ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 25°C (77°F) at a pressure alt. of 1,534m (5,033ft)R. Dewpoint Temp (collected at same location as temp inside eye): 18°C (64°F)R. Sea Surface Temp (collected at same location as temp inside eye): Not AvailableS. Fix Determined By: Penetration, Wind and PressureS. Fix Level: 850mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 5 nautical milesRemarks Section: Maximum Flight Level Wind: 59kts (~ 67.9mph) which was observed 11 nautical miles (13 statute miles) to the SE (134°) from the flight level center at 5:12:00Z Maximum Flight Level Temp: 26°C (79°F) which was observed 11 nautical miles (13 statute miles) to the NW (313°) from the flight level center

Sorry for all the rapid fire posts. Finishing up the NW to SE pass, recon finds peak FL (flight level wind) of 58kt and unflagged SFMR of 53 and 54kt, confirming the 11pm wind in the advisory.