-
Posts
4,611 -
Joined
-
Last visited
Content Type
Profiles
Blogs
Forums
American Weather
Media Demo
Store
Gallery
Everything posted by Windspeed
-
000 WTNT45 KNHC 190240 TCDAT5 Tropical Storm Jerry Discussion Number 7 NWS National Hurricane Center Miami FL AL102019 1100 PM AST Wed Sep 18 2019 Jerry is gradually becoming better organized, with a small circular CDO and some banding features over its northwestern quadrant. Although the storm has some modest upper-level outflow, there is evidence of west-northwesterly winds undercutting the system just below the outflow layer. An upper-level cyclone is located a few hundred miles to the northwest of Jerry, as confirmed by synoptic surveillance observations taken recently by the NOAA G-IV jet. However, the global models suggest that this feature should remain far enough to the north of the tropical cyclone so that its shearing influence will be minimal in the short term. The current intensity estimate is 55 kt based on Dvorak classifications from TAFB and SAB. Since the environment is likely to be modestly conducive during the next day or so, strengthening is predicted for the next 24 hours. Thereafter, the dynamical guidance shows some increase in shear, which should result in a leveling off of Jerry's intensity. Later in the forecast period, the global models predict a significant increase in shear, so some weakening is likely. The official intensity forecast is close to the multi-model consensus. The storm remains on track with the motion continuing around 290/13 kt. There are no important changes to the track forecast from the previous advisory. Jerry should move along the southwestern periphery of a subtropical ridge over the next couple of days. In 3-5 days, the tropical cyclone is likely to turn northwest, north-northwest, and eventually north following a weakness in the ridge near 70-75W longitude. The official track forecast is close to the latest corrected multi-model consensus guidance. Key Messages: 1. Jerry is expected to become a hurricane before it moves close to the northern Leeward Islands Friday. Although the core of Jerry is currently expected to pass north of the islands, tropical-storm- force winds and locally heavy rainfall are possible, and tropical storm watches have been issued for a portion of this area. FORECAST POSITIONS AND MAX WINDS INIT 19/0300Z 15.4N 51.8W 55 KT 65 MPH 12H 19/1200Z 16.2N 53.9W 65 KT 75 MPH 24H 20/0000Z 17.3N 56.7W 75 KT 85 MPH 36H 20/1200Z 18.5N 59.7W 75 KT 85 MPH 48H 21/0000Z 19.7N 62.7W 75 KT 85 MPH 72H 22/0000Z 22.4N 67.3W 70 KT 80 MPH 96H 23/0000Z 25.7N 70.0W 65 KT 75 MPH 120H 24/0000Z 29.0N 69.0W 65 KT 75 MPH $$ Forecaster Pasch
-
That's so far out there in advance, anything is possible. More concerned about the Northern Lesser Antilles for now because if we have a more intense and deeper vortex, it will be more susceptible to influence by the deeper 400 mb steering flow. Again, the more intense Jerry becomes in the short term, the more shift south in track. A bit opposite from typical steering (i.e. stronger more northerly) but it's due to positioning of the upper ridge.
-
Again, that MW pass is highly suggestive of an aligning vortex. If that is the case, that banding may very well be core formation in progress as well. Jerry may be about to undergo stronger intensification. I won't say rapid, but the jog south will have got it further away from the NE shear axis, which could allow it to organize more quickly. I certainly would not rule out RI though.
-
This is actually the type of pattern to get a Mid-Atlantic impact. Though most systems may recurve, not every storm will. Still, getting multiple hurricanes to track north of the Antilles near and north of the Bahamas versus over-amped ridging and Caribbean runners, you increase the chance of enough ridging in place with one of these storms to make impacts on the eastern seaboard. Even Dorian was still an impact for the coastal Carolinas, even if it was mostly just a hit on the barriers. You have to look at the overall pattern in place. This pattern actually increases the odds of interaction versus a pattern that removes you entirely. 2004 and 2005 are prime examples. Crazy active years with many devestating impacts for everyone outside the Mid-Atlantic, but because of the pattern in place those years, everything went south through Florida, the Gulf or smashed the Caribbean. The Mid-Atlantic and New England were relegated to chirping crickets.
-
There is a 400mb ridge imparting NE flow into TS Jerry by Humberto's presence right now. This is what Levi is focusing on and though it's not resulting in horrible mid-level shear, it may be enough to keep any RI phase in check, limiting Jerry to slow strengthening in the coming days. On the other hand, if Jerry's position versus said ridge offsets the shear somewhat, and Jerry becomes a strong hurricane much faster, the deep layer steering flow would potentially get the core into the Northern Lesser Antilles. So that does need to be watched. Edit: Note the EPS members representing a strong hurricane are further south. That's due to that upper mid-level influence if Jerry was to be a more intense and deeper vortex it would feel that somewhat. But it's more likely Jerry is much slower with development and any deep steering layer would not be as influential.
-
2019 Atlantic Hurricane Season
Windspeed replied to AfewUniversesBelowNormal's topic in Tropical Headquarters
There are already TS force sustained winds being observed. I suspect this may be the shortest classified TD on record as they may upgrade momentarily. lol... Somebody want to do the honors and make a thread? -
2019 Atlantic Hurricane Season
Windspeed replied to AfewUniversesBelowNormal's topic in Tropical Headquarters
Something I would like to point out as a reminder about the NHC Outlook's hatched regions with respect to potential cyclone development: These are not intended to be a representation of track nor to be confused as track guidance, they are merely to show a most probable region for a disturbance / area of invest to undergo cyclogenesis. Too many times I see reference to these discussed as forecast track, when in reality, any cyclogenesis that occurs could begin to track towards another direction once a system has been classified. For example, 95L's sharp wave axis or area of low pressure could form a vortex at highest forecast probability anywhere within that hatched zone, but the classified depression or tropical cyclone could immediately begin tracking west from initialization, north or even northeast. I am not accusing anyone of this in current discussion with 95L, but I have certainly seen it done here in the past and elsewhere. Additonally, this is also why the NHC will usually use arrows from an invest's location to a hatched region when they feel it will not develop at its current location. In that case, you can assume some track for the disturbance in an official sense, but only to the region of expected higher probs for cyclogenesis. Before any of this, it's just model slag discussion really. -
2019 Atlantic Hurricane Season
Windspeed replied to AfewUniversesBelowNormal's topic in Tropical Headquarters
-
2019 Atlantic Hurricane Season
Windspeed replied to AfewUniversesBelowNormal's topic in Tropical Headquarters
-
Yeah I am infuriated. What does it even mean to be an American anymore with shit like this happening?
-