WxWatcher007

The 12z Euro basically leaves Franklin behind after looping over Bermuda! That's like a 1500 mile trend over 24 hours. That's extraordinary, and would almost certainly make Franklin a big ACE producer.

With the massive shifts we're seeing on the guidance with regard to the steering pattern post landfall, there's a lot of uncertainty on where this eventually ends up after Florida, and if it gets left behind by the northeast trough. I know that's far out, but it's something of interest for the SE coast folks.

I am really fascinated by this. It has been a truly appalling performance by the models on Franklin. Now the Euro basically takes Franklin from west to east near or over Bermuda. These are massive shifts at medium range.

On TT I like using 200-850mb wind shear, and the same 200-850mb wind shear anomaly plot for pattern recognition. Going deeper, I love using the 355k Potential Vorticity plots as well to recognize TUTT development/movement/strength. Of course, you have the averaged soundings that can be used as well.

Euro short range still wants to take this near or over the Yucatan in the next 24 hours, so I suppose that's still something to watch. All the globals still playing catch up though to the organization we've seen so far.

No surprise, but the NHC is telegraphing advisories later today. Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 PM EDT Sat Aug 26 2023 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: Active Systems: The National Hurricane Center is issuing advisories on recently upgraded Hurricane Franklin, located several hundred miles south of Bermuda. Northwestern Caribbean Sea and Eastern Gulf of Mexico (AL93): Showers and thunderstorms associated with an area of low pressure located near the Yucatan Channel continue to gradually become better organized. If this trend continues, advisories will be initiated on this system later today. The system is expected to move very slowly northward into the southeastern Gulf of Mexico during the next couple of days. Heavy rains are likely over portions of western Cuba and the Yucatan Peninsula of Mexico. Interests in the Yucatan Peninsula of Mexico, western Cuba, and Florida should monitor the progress of this system. * Formation chance through 48 hours...high...90 percent. * Formation chance through 7 days...high...90 percent.

Agree. I really think it’s land interaction at least initially. The visible has been impressive, but look at the Cancun radar. This is a TD imo and if it’s not it’s damn close. https://bmcnoldy.earth.miami.edu/tropics/radar/

Hurricane Franklin Discussion Number 24 NWS National Hurricane Center Miami FL AL082023 1100 AM AST Sat Aug 26 2023 Franklin has become better organized this morning on satellite and microwave imagery. An earlier SSMIS microwave pass showed a developing core with the mid and low-level center becoming more vertically aligned. Early visible satellite images showed a ragged eye, which has become cloud filled in the last hour or two. Deep convection around Franklin has become more symmetric compared to recent days, likely due to a decrease in vertical wind shear. Air Force and NOAA Hurricane Hunters have been in the system this morning, and found that the surface pressure has dropped to 989 mb and SFMR winds were around 60 to 65 kt from both aircraft. Given the data from the aircraft reconnaissance, Franklin has been upgraded to a Hurricane, with the initial intensity set at 65 kt. Franklin is the second hurricane of the 2023 Atlantic hurricane season. Franklin is moving north-northwestward at 6 kt. A north-northwestward to northward motion is forecast during the next few days as the storm moves along the western periphery of a mid-level ridge, taking it to the west of Bermuda on Tuesday. By the middle of next week, a faster northeastward motion is expected when Franklin moves in between the ridge and a mid- to upper-level trough over eastern Canada and the northeastern United States. The track models have shifted to the west once again this cycle, and the NHC track forecast follows that trend and is slightly slower than the previous one at long ranges. Franklin is expected to steadily strengthen during the next few days with lower vertical wind shear, and warm sea surface temperatures in the western Atlantic. Franklin is forecast to become a major hurricane early next week. The strengthening trend should end in about 3 to 4 days with shear expected to increase. By Day 5, the system will move over much cooler SSTs leading to increased weakening. The intensity models are higher this cycle, and the NHC forecast has been nudged upward, but still remains below the IVCN and HCCA consensus models. FORECAST POSITIONS AND MAX WINDS INIT 26/1500Z 23.5N 66.7W 65 KT 75 MPH 12H 27/0000Z 24.2N 67.0W 70 KT 80 MPH 24H 27/1200Z 25.4N 67.8W 80 KT 90 MPH 36H 28/0000Z 27.0N 68.8W 90 KT 105 MPH 48H 28/1200Z 28.5N 69.4W 100 KT 115 MPH 60H 29/0000Z 30.2N 69.5W 105 KT 120 MPH 72H 29/1200Z 31.9N 69.0W 105 KT 120 MPH 96H 30/1200Z 35.6N 65.9W 90 KT 105 MPH 120H 31/1200Z 40.5N 56.9W 75 KT 85 MPH $$ Forecaster Kelly/Pasch

93L looking good this morning

This longer length loop really shows the organizational trend. Far more consolidated, with continuing vigorous convection. I don't think a LLC is directly under the center of the convective canopy, but this 1) looks further organized than the guidance suggests 2) currently lies in a highly favorable environment for further development, hence the 70/90% odds 3) has a greater chance of staying offshore given the consistent convective bursts to the east of the Yucatan This is a good look for an invest. The more organized it becomes this weekend the more resilient it will be to shear/dry air in the Gulf. Really have to see if land interaction can disrupt this trend.

Should be a hurricane at 11am. Hurricane models get this to MH status in a few days and the NHC endorsed that in its 5am update.

First light

Closed eye per recon. Product: Air Force Vortex Message (URNT12 KNHC)Transmitted: 26th day of the month at 11:57ZAgency: United States Air ForceAircraft: Lockheed WC-130J Hercules with reg. number AF97-5306Storm Name: FranklinStorm Number & Year: 08 in 2023 (flight in the North Atlantic basin)Mission Number: 11Observation Number: 05 ( See all messages of this type for this mission. )A. Time of Center Fix: 26th day of the month at 11:38:10ZB. Center Fix Coordinates: 23.20N 66.54WB. Center Fix Location: 333 statute miles (536 km) to the N (355°) from San Juan, Puerto Rico (U.S.).C. Minimum Height at Standard Level: 3,000m (9,843ft) at 700mbD. Minimum Sea Level Pressure: 989mb (29.21 inHg)E. Dropsonde Surface Wind at Center: From 50° at 7kts (From the NE at 8mph)F. Eye Character: ClosedG. Eye Shape & Diameter: Circular with a diameter of 18 nautical miles (21 statute miles)H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 49kts (56.4mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 9 nautical miles to the SSW (211°) of center fix at 11:35:30ZJ. Maximum Flight Level Wind Inbound: From 308° at 42kts (From the NW at 48.3mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 21 nautical miles (24 statute miles) to the SW (221°) of center fix at 11:32:00ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 68kts (78.3mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 13 nautical miles (15 statute miles) to the NE (39°) of center fix at 11:42:00ZN. Maximum Flight Level Wind Outbound: From 133° at 57kts (From the SE at 65.6mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 14 nautical miles (16 statute miles) to the NE (41°) of center fix at 11:42:30ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 9°C (48°F) at a pressure alt. of 3,049m (10,003ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 14°C (57°F) at a pressure alt. of 3,047m (9,997ft)R. Dewpoint Temp & Sea Surface Temp: Not AvailableS. Fix Determined By: Penetration, Radar, Wind and PressureS. Fix Levels (surface & flight level centers within 5nm of each other): Surface and 700mbT. Navigational Fix Accuracy: 0.02 nautical milesT. Meteorological Accuracy: 3 nautical milesRemarks Section: Maximum Flight Level Wind: 57kts (~ 65.6mph) which was observed 14 nautical miles (16 statute miles) to the NE (41°) from the flight level center at 11:42:30Z Maximum Flight Level Temp: 14°C (57°F) which was observed 6 nautical miles to the SSW (203°) from the flight level center

Tropical Weather Outlook NWS National Hurricane Center Miami FL 800 AM EDT Sat Aug 26 2023 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: Active Systems: The National Hurricane Center is issuing advisories on Tropical Storm Franklin, located several hundred miles south of Bermuda. Northwestern Caribbean Sea and Eastern Gulf of Mexico (AL93): Shower and thunderstorm activity continues to show signs of organization in association with an area of low pressure located near the Yucatan Channel. Environmental conditions appear conducive for further development of this system, and a tropical depression is likely to form within the next day or two while it moves generally northward over the southeastern Gulf of Mexico. Interests in the Yucatan Peninsula of Mexico, western Cuba, and Florida should monitor the progress of this system. * Formation chance through 48 hours...high...70 percent. * Formation chance through 7 days...high...90 percent.

988.9mb extrapolated pressure with a peak FL wind of 57kts. Some SFMR have been over 64kt, but apparently SFMR readings have been high in Franklin before. If it's not a hurricane, it's getting close.

Certainly possible, though this one looks a little ahead of the modeling schedule for organization, at least at the mid levels. Of course, any early "progress" could be lost if this slides and sits over the Yucatan today, but the eastward development of a possible vigorous MLC is intriguing.

Recon approaching the eye.

Invest 93L continues to organize this morning under an ULAC. It's very hard to get a sense of how much organization we have of the low levels without visible satellite and microwave imagery, but looking at a much longer version of IR just now, it looks like at least the mid-level circulation is developing east of the Yucatan. You can see it a bit with those towers rotating in the image above. Even if an LLC isn't under the convection currently, the consistent and strong convection we see this morning could either work to the surface with sufficient time or pull a misaligned LLC east. SW IR presents a similar picture. You can see a clearly consolidating circulation, but it's hard to tell if there's a true LLC and where. There may be evidence of outflow developing, another sign of organization. There has been consistent convection through the night, which has become more organized the last few hours. First light will be telling, but given the convective activity and appearance if this holds we probably see at least a PTC today to cover the Yucatan.

Speaking of odd structure—it’s got a partial eyewall going at first light and possible eye. Recon en route but this could be a hurricane today if that keeps up.

Keep in mind that the HWRF is in the process of retirement so I’d look at HAFS-A/B now. (and that the hurricane models are prone to large errors when there isn’t a well defined LLC)

Tropical Storm Franklin Discussion Number 22 NWS National Hurricane Center Miami FL AL082023 1100 PM AST Fri Aug 25 2023 Westerly shear continues to affect Franklin tonight, as evidenced by the sharp edge to its cold cloud tops on infrared satellite images. However, the low-level center that was exposed earlier today appears to have moved under the western edge of the convective canopy. An Air Force Reserve Hurricane Hunter aircraft flew the storm at 700 mb this evening and reported peak flight-level winds of 56 kt, with believable SFMR winds in the 45-55 kt range. These data warrant a slight increase to the initial intensity (50 kt), especially given a recent dropsonde that suggests the surface pressure has fallen to 996 mb tonight. A recent ASCAT-B pass over Franklin further supports this, with peak wind vectors slightly above 45 kt. Note that the initial intensity of Franklin is more uncertain than normal, with there being a large spread between some of the aircraft data and the various objective and subjective satellite estimates. The intense convection closer to the center of Franklin appears to have drawn the surface center more northeastward, and the initial motion is an uncertain 60/7 kt. A high pressure ridge building to the east of Franklin is expected to steer the cyclone more northward and north-northwestward this weekend and into early next week. Then, a deep-layer trough is forecast to move across the northeastern U.S. and eastern Canada by midweek. This should cause Franklin to accelerate northeastward deeper into the mid latitudes through the end of the forecast period. The updated NHC track forecast lies to the east of the previous one during the first 60-72 h of the period, mainly a result of the eastward adjustment to the initial position of Franklin. There are some notable forward speed differences beyond 72 h, with the GFS significantly faster than the rest of the global and regional models. With the NHC forecast remaining near the multi-model consensus aids, no notable changes were made to this portion of the track forecast. The westerly shear that has plagued Franklin for the past couple of days is expected to decrease during the next 24-36 h. So while only modest strengthening is forecast in the near term, more significant strengthening seems likely thereafter as the cyclone moves over very warm SSTs (29-30 deg C) and within a more favorable dynamic environment. The updated forecast shows Franklin becoming a hurricane by 48 h and peaking near major hurricane intensity in 72-96 h, in good agreement with the latest HCCA and IVCN aids. As Franklin accelerates to higher latitudes, cooler waters and increased deep-layer shear will induce weakening and eventually extratropical transition beyond the end of the forecast period. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 22.4N 66.2W 50 KT 60 MPH 12H 26/1200Z 23.0N 66.0W 55 KT 65 MPH 24H 27/0000Z 23.9N 66.3W 55 KT 65 MPH 36H 27/1200Z 25.3N 67.0W 60 KT 70 MPH 48H 28/0000Z 27.0N 67.9W 70 KT 80 MPH 60H 28/1200Z 28.8N 68.4W 80 KT 90 MPH 72H 29/0000Z 30.5N 68.4W 95 KT 110 MPH 96H 30/0000Z 34.7N 66.5W 95 KT 110 MPH 120H 31/0000Z 40.0N 60.0W 75 KT 85 MPH $$ Forecaster Reinhart

18z EPS

Right. Having a higher ceiling doesn’t mean it gets reached. Land interaction and sneaky shear imparting dry air, along with limited time over the Gulf could easily hold this back. Also, it takes time to organize an inner core, which is an absolute essential for higher end development. It’s too early to say exactly where this is headed.

Somewhat divergent steering pattern that needs to be worked out.