Windspeed

Despite the ongoing GOES 16 data issues, it appears spiral banding is established and spiraling into the circulation center. TD22 is looking more and more like a TS. Perhaps this will be enough for the NHC to upgrade despite having to wait until this afternoon/evening for the next recon flight.

And on with the theme of #2020things. Recon got struck by lightning on the way to TD22. We'll have to wait and see what's going on under the hood of recent robust convection.

As if Sally's forecasting wasn't a real pain. This is going to take some tremendous patience. I feel the rest of my hair turning grey.

000 WTNT42 KNHC 180243 TCDAT2 Tropical Depression Twenty-Two Discussion Number 2 NWS National Hurricane Center Miami FL AL222020 1000 PM CDT Thu Sep 17 2020 Inspection of flight-level wind data from the earlier Air Force Reserve mission indicates that the depression has a somewhat elongated circulation, but a sufficiently well-defined center and pressure minimum were found just to the west of NOAA buoy 42055. The plane measured maximum surface winds of 30 kt in the deep convection to the southwest of the center using the SFMR instrument, and that remains the initial intensity. As best as I can tell, the depression is moving very slowly northeastward with an initial motion of 035/3 kt. A positively tilted mid- to upper-level trough extends across Texas and northern Mexico, and this feature should cause the depression to move toward the north-northeast during the next 36 hours. The trough is expected to dissolve soon after that time, with a mid-tropospheric high building over the south-central United States. The high should force the cyclone to turn and move very slowly westward on days 3 and 4, and then potentially stall or meander off the lower Texas/ northeastern Mexico coast by day 5. There is lower-than-normal confidence in the official track forecast due to fairly significant spread among the track guidance. However, the models do agree on the general scenario, and they all suggest that the depression is unlikely to move a whole lot for the entire forecast period. This new NHC forecast lies very close to the TVCN multi-model consensus. Unfortunately, there is also significant uncertainty in the intensity forecast. Light-to-moderate southerly to southwesterly shear is expected to affect the depression for the next couple of days while it moves over very warm waters of 30-31 degrees Celsius and in a very moist environment. Things change quickly after 48 hours due to a cold front entering the northern Gulf, and the drier, more stable air mass behind the front could be entrained into the cyclone's circulation from day 3 to day 5. The GFS- and ECMWF-based SHIPS models show the most significant strengthening, bringing the intensity to 75-80 kt in about 3 days, while many of the other intensity models don't even raise it to hurricane intensity. As a compromise between these various solutions, the NHC intensity forecast shows the cyclone just reaching the hurricane threshold in 2-3 days and then gradually weakening thereafter due to the less favorable environment. However, it cannot be stressed enough that this forecast is highly uncertain. Key Messages: 1. Tropical Depression Twenty-Two is expected to strengthen to a tropical storm, and possibly a hurricane, while moving slowly over the western Gulf of Mexico during the next few days. 2. While it is too early to determine what areas could see direct wind, storm surge, and rainfall impacts from this system, interests throughout the western Gulf of Mexico should monitor the progress of this system and future updates to the forecast. FORECAST POSITIONS AND MAX WINDS INIT 18/0300Z 22.0N 94.2W 30 KT 35 MPH 12H 18/1200Z 22.9N 93.8W 35 KT 40 MPH 24H 19/0000Z 23.9N 93.3W 45 KT 50 MPH 36H 19/1200Z 24.8N 92.9W 55 KT 65 MPH 48H 20/0000Z 25.4N 93.2W 60 KT 70 MPH 60H 20/1200Z 25.6N 94.0W 65 KT 75 MPH 72H 21/0000Z 25.7N 94.8W 65 KT 75 MPH 96H 22/0000Z 26.1N 95.9W 60 KT 70 MPH 120H 23/0000Z 26.4N 96.0W 55 KT 65 MPH $$ Forecaster Berg

The WMO won't retire the Greek alphabet.

The Mediterranean Sea is part of the Atlantic Ocean but is not assigned an RMSC (Regional Specialized Meteorological Centre) probably due to the scarcity of TCs and STCs there in the satellite era. But they do occur and something formal should probably be done about it. The most logical choice would be MeteoFrance since they already have an RMSC in the Indian Ocean and provisional remote sensing technology in place with the EU to observe, forecast and assist member and bordering coastal nations with advisory products.

Looks like the center made landfall on the island of Kefalonia (Cephalonia). Though Zakynthos, the island south of Kefalonia is in the southern circulation and likely feeling the worst effects.

lol that CMC/GEM op run was also an SST killer for the remainder of the season in the GOM. That would shut it down.

Looks like the MJO will transition to a brief suppressive regime next week as an unfavorable CCKW swings across the N. Atlantic Basin. However, that is followed by another enhancing CCKW leading into October. Therefore, things could get quiet briefly following Teddy and the potential GOM system followed by another uptick towards the end of the month. Of course it is important to remember that positive (red) MJO regimes are not as unfavorable during peak weeks as TCG can still occur in the Caribbean, GOM and MDR as overall surface pressures tend to have decreased versus mid-Summer months. Pockets of favorable upper 200 hPa vorticity can still be obtained over random areas, especially with lacking EPAC TC activity. In addition, the MDR has tended to moisten somewhat with a backdown in pressure heights and 700 hPa easterlies. So we could still see something pop up east of the Antilles as well.

Might be semantics but I kind of hope recon does find a TS beyond just a classified depression. Reason being that there doesn't appear to be any reason why this won't eventually get named as it looks to be getting better and better organized. However it's quite possible the EATL subtropical system will gain enough organization by 5 PM AST to get named as it is already a vigorous subtropical circulation with TS force winds in the eastern semicircle. Granted, data is data, but 90L could become a real big problem for someone on the GOM coast and I'd rather it get a legitimate seasonal name that could be retired if an unfortunate bad scenario unfolds.

And just like that, we're a go for recon...

90L looks to have several areas of vorticity along the axis of the elongated surface trough. However, in the last three or four hours, it looks like a dominate vorticity maximum is taking over along the southwest extension of the trough. Really need recon. Somewhere in this mess may be a closed surface circulation. If it happens to be under that more dominate mid level vort max, we may have ourselves a TC.

A low pressure system SSE of the Italy/Anatolia Peninsula in the Ionian Sea has become warm core and acquired TC characteristics. It has a nascent eye feature and good banding, likely producing strong TS force sustained winds and potential hurricane gusts. It is forecast to make landfall in Greece. Translation from Meteo EU: https://weather.us/satellite/ionioi-nisoi/satellite-hd-5min/20200917-1145z.html

A low pressure system over the far eastern Atlantic, 99L, is transitioning more warm core with time. It would of course be fitting for 2020 if a Subtropical Storm grabs the last seasonal name prior to the Greek alphabet. lol... Perhaps 90L can get its act together in short order today and snatch the name away. The race is on...

Recon is scheduled for today. By the time they get there, this may be a depression or even a TS. Thunderstorm activity has continued to increase and become better organized this morning in association with a well-defined low pressure system located over the southwestern Gulf of Mexico. Upper-level winds are gradually becoming more conducive for development and, if this recent development trend continues, a tropical depression or a tropical could form later today. The low is expected to meander over the southwestern Gulf of Mexico for the next day or so before moving slowly northward to northeastward on Friday and Saturday. An Air Force Reserve reconnaissance aircraft is scheduled to investigate the disturbance this afternoon. * Formation chance through 48 hours...high...90 percent. * Formation chance through 5 days...high...90 percent.

ACE isn't the only standard though. People who only consider it to be are foolish. Landfalls are critical data. Cost is important data. Number of storms are critical data. However, ACE shouldn't be done away with as it is an important climatological tool for measuring and comparing basins. Also, it's a great data filter for finding the most active seasons. It's no coincidence that seasons with the highest ACE had numerous powerful TCs beyond just having a high total number of TCs. You also usually find some real long-tracking beasts as well.

I don't really pay the ops too much mind for intensity. Sure, it's eye-opening when they go bonkers on a particular system. You do want it to show a deep versus shallow feature, especially in the mid-levels. But generally the global ops have underperformed on intensity for systems that have not yet developed this year. Of course the TC models handle that better once a TCG has occurred however, which what they are better designed for.

Well we should have some recon flights during peak since it will eventually be a land threat (Bermuda or possibly NE/NS, etc). You're probably meaning on the ground in situ though. I bet you had no love for Lorenzo. [emoji17]

Teddy has a shot at Cat 5. It'll be moving over 29°C SSTs tomorrow within a divergent environment. Definitely going to be a Category 4 and most likely a high end one during its life cycle.

Well that's not good.

Going ahead with a thread for 90L. It already has the appearance on visible in the lower level cloud field of possessing a closed surface low. This may get classified by this evening and be a landfall threat in Mexico or possibly S. Texas. Another slow mover and flooding threat.

ACE is now skyrocketing. We should be over 100 sometime next week.