WxWatcher007

Significant shift east on the guidance so far today away from direct Atlantic Canada impacts.

I wouldn’t be posting this much if I weren’t home sick Tropical Storm Franklin Discussion Number 8 NWS National Hurricane Center Miami FL AL082023 1100 AM EDT Tue Aug 22 2023 It is unclear this morning if Franklin still has a well-defined center of circulation. Visible satellite images suggest that broad low-level turning is occurring well to the west of the bulk of Franklin's deep convection, and there is no clear evidence that a center exists near, or that a new center if re-forming beneath, the convection. It appears that scatterometer will miss Franklin and be of no help in assessing the wind field, but a NOAA Hurricane Hunter aircraft is scheduled to investigate the system later this afternoon. For now, the initial intensity is held at 45 kt, which is right in the middle of the various subjective and objective satellite estimates. If Franklin does still have a center, it is assumed to have jumped or re-formed a bit to the west where there is new convection. This position gives the storm an overall motion over the past 12 hours toward the northwest (325 degrees) at 6 kt. Franklin is positioned within the southern extent of a large mid-level trough, which includes a mid-/upper-level low centered south of Bermuda. While the steering flow is weak, this should cause Franklin to move slowly northward and then northeastward for the next 4 days or so. By day 5, a new shortwave trough is likely to develop over New England, with ridging strengthening over the central Atlantic, and Franklin is forecast to turn back toward the north at that time. Largely because of the adjustment in the initial position, all of the track guidance has shifted westward on this cycle. The NHC track forecast has also been moved westward, although it is on the eastern side of the guidance envelope and fairly close to the typically-reliable HCCA consensus aid. That said, there is greater-than-usual uncertainty in Franklin's forecast track given potential re-formations of the center. Moderate-to-strong westerly shear is expected to continue over Franklin for the next 4 days or so. In addition, the system is forecast to move over the rugged terrain of Hispaniola within the next 24-36 hours. As a result, little change in strength is anticipated before Franklin reaches Hispaniola, and some weakening is likely while it is crossing the island. Some intensification is then noted in the 3-5 day period when environmental conditions begin to become a little more conducive for strengthening. The NHC intensity forecast is near the HCCA and IVCN consensus aids for much of the 5-day forecast period. KEY MESSAGES: 1. Heavy rainfall from Franklin is expected across portions of Puerto Rico and Hispaniola into Thursday. The heavy rainfall may produce areas of flash and urban flooding as well as river rises and mudslides. Across Hispaniola, significant and potentially life-threatening flash flooding is possible Tuesday into Wednesday. 2. Franklin is expected to bring tropical storm conditions to portions of the Dominican Republic and Haiti, where Tropical Storm Warnings are in effect, beginning later today and continuing through Wednesday. FORECAST POSITIONS AND MAX WINDS INIT 22/1500Z 15.5N 71.1W 45 KT 50 MPH 12H 23/0000Z 16.5N 71.3W 50 KT 60 MPH 24H 23/1200Z 18.3N 70.9W 45 KT 50 MPH...S COAST OF DOM REPUB 36H 24/0000Z 20.4N 70.2W 40 KT 45 MPH...OVER WATER 48H 24/1200Z 22.1N 69.3W 40 KT 45 MPH 60H 25/0000Z 22.9N 68.2W 45 KT 50 MPH 72H 25/1200Z 23.3N 67.1W 50 KT 60 MPH 96H 26/1200Z 24.2N 66.3W 60 KT 70 MPH 120H 27/1200Z 27.1N 67.1W 70 KT 80 MPH $$ Forecaster Berg

Landfall at Padre Island. 50mph/998mb

Spot on. We’ve had our windows and have produced, but the impact has been marginal relative to what we could do. We had a lot of those systems weaken substantially on approach, and even though some have been high impact, we haven’t really seen a big widespread deal. It’ll happen eventually, but a lot has to go right (or wrong) for the perfect storm. Turning to the basin, Harold has ramped up quickly but ran out of runway. Get a real Gulf system this year and it’ll be trouble, again…

Look at that pressure fall. These quick spin ups are always fascinating.

Quickly building an eyewall just offshore. Runway to take off is almost gone, though.

Harold looking pretty robust as landfall approaches

Pretty potent look rolling up on the coastline. Good job by the models to show this evolution without overdoing it.

Just like “winter”!

October has produced recently

Kudos to the euro that basically had this forecasted a few days ago.

Yeah this is from that EPAC monsoon trough/CAG feature I started highlighting last Wednesday. Models have been lukewarm until the euro brought it back last night. I thought last week that had the highest potential for the final week of August, but even with last nights run the euro remains an outlier. The MT is there, but no guarantees anything crosses over. NHC not highlighting any contenders either. It’s really just wait and see like the Atlantic MT was? https://tropic.ssec.wisc.edu/real-time/atlantic/movies/wg8vor4/wg8vor4_loop.html

Right but that’s just how it goes. The steering pattern has been generally conducive the last decade or so for tropical. Turning to the basin now, still think Atlantic Canada needs to watch Franklin. Euro goes back to the CAG leading to something in the Caribbean/Gulf homebrew region in just a few days. Models have flirted with that idea but nothing has been really solid. I started talking about that CAG potential last Wednesday lol. I may love wx, but I’m obsessed with tropical

Yep—an instance here where a TC can do more good than harm.

First VDM. That high SFMR almost certainly came from a gust. Product: Air Force Vortex Message (URNT12 KNHC)Transmitted: 22nd day of the month at 6:18ZAgency: United States Air Force Aircraft: Lockheed WC-130J Hercules with reg. number AF97-5304 Tropical Depression: Nine (flight in the North Atlantic basin)Mission Number: 2Observation Number: 03 ( See all messages of this type for this mission. )A. Time of Center Fix: 22nd day of the month at 5:32:10ZB. Center Fix Coordinates: 25.62N 94.19WB. Center Fix Location: 206 statute miles (332 km) to the E (96°) from Brownsville, TX, USA.C. Minimum Height at Standard Level: 723m (2,372ft) at 925mbD. Minimum Sea Level Pressure: 1004mb (29.65 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: 52kts (59.8mph)I. Location & Time of the Estimated Maximum Surface Wind Inbound: 58 nautical miles (67 statute miles) to the NE (41°) of center fix at 5:13:30ZJ. Maximum Flight Level Wind Inbound: From 112° at 52kts (From the ESE at 59.8mph)K. Location & Time of the Maximum Flight Level Wind Inbound: 59 nautical miles (68 statute miles) to the NE (41°) of center fix at 5:13:00ZL. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 18kts (20.7mph)M. Location & Time of the Estimated Maximum Surface Wind Outbound: 40 nautical miles (46 statute miles) to the SW (228°) of center fix at 5:44:30ZN. Maximum Flight Level Wind Outbound: From 4° at 12kts (From the N at 13.8mph)O. Location & Time of the Maximum Flight Level Wind Outbound: 48 nautical miles (55 statute miles) to the SW (228°) of center fix at 5:47:00ZP. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 18°C (64°F) at a pressure alt. of 758m (2,487ft)Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 760m (2,493ft)R. Dewpoint Temp (collected at same location as temp inside eye): 21°C (70°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: 52kts (~ 59.8mph) which was observed 59 nautical miles (68 statute miles) to the NE (41°) from the flight level center at 5:13:00Z Sea Level Pressure Extrapolation From: 925mb

We have Harold as of 2am EST WxWatcher007 Peak Season Forecast (Aug 20-Oct 20) Named Storms: 13 (4) Hurricanes: 6 (0) Major Hurricanes: 3 (0) Edit: it’s 4 TCs since Aug 20—Emily, Franklin, Gert, Harold.

1:00 AM CDT Tue Aug 22 Location: 25.8°N 94.4°W Moving: WNW at 18 mph Min pressure: 1004 mb Max sustained: 45 mph

LLC is displaced SW of the convective bursts. Lowest extrapolated pressure so far 1004.4mb at ~2,500ft. We’ll see if the first pass is enough for the NHC to upgrade.

Rain contaminated higher gusts but there are some FL and SFMR obs that look clean enough at minimal TS strength IMO. Still a lot more to sample.

It’s much better convectively organized on satellite, but that west side still looks odd to me. Recon is starting to sample so we’ll see soon.

Recon in the air now. If I’m awake I’ll post what they find. Good time to head in.