Author: David Reimer

Tropical Storm Bonnie – Discussion #2

Good Morning. Like I said yesterday I plan on doing one discussion a morning unless something comes up, in which case I’ll do supplemental discussions such as I did yesterday afternoon. The graphic above depicts the model outputs on the track of Tropical Storm Bonnie. These are from the 06Z suite this morning. The models have kept a fairly uniform track over the past day with a landfall in Southeastern Louisiana. They have sped up the system, however, which has brought the landfall time up about twelve hours to the pre-dawn hours on Sunday. Tonight the system has been racing moving at speeds over 20 MPH. That’s pretty high for a tropical system and when recon entered Bonnie earlier this morning the question of whether or not this still was a tropical system (of any kind) become clear. The first thing to notice about Bonnie this morning is the very small area convection is covering, although it is fairly strong for a system this weak. The problem is that the Low Level Circulation has become detached from that convection, and thus has weakened overnight. When the Hurricane Hunters entered the system at 2 AM CDT they had difficulty finding any west winds, which would indicate a low level circulation, and thus a tropical system. Without a low level circulation this is nothing more then an open wave or a...

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Tropical Depression #3 – 20Z Update

Good Afternoon, This is going to be a brief update regarding the development of Tropical Depression #3. Obviously the system did gain some organization since the discussion I posted earlier this morning, as NHC decided to upgrade to a TD. Aircraft Recon has been in the system for most of the afternoon and has found that despite its current meager satellite appearance, likely due to the diurnal max, that TD2 has been organizing with the pressure falling from 1008 MB to 1006 MB in about an hour. Here’s the latest image from the recon mission as of the time of this posting. Click the image for a full-sized version. As of the time of this posting the National Hurricane Center has not found enough evidence to support an upgrade to Tropical Storm Strength (34 Kts). For those who did read this morning’s discussion you noted where I mentioned there was an exceptional amount of wind shear over the system which was preventing any development of a low level circulation. Fast forward 12 hours… As of 1 PM CDT the shear over the system had dropped over significantly and is continuing to decrease. This should help the system to at least maintain its organization this afternoon into this evening. The forecast regarding the strength of the system remains tricky due to many factors that could come into play later on...

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Invest 97 (Bonnie?) – Discussion #1

Good Morning, Two days ago Invest 97 looked like it was well on its way to becoming a tropical depression by this point in time, but the convection associated with it weakened and for most of the day yesterday we were wondering if Invest 97 would survive the night. However, late yesterday afternoon it sparked off new convection which has maintained itself overnight. A gulfstream aircraft confirmed that strong wind shear is impacting the system, but its a good sign to see convection tonight. Right now the convection is displaced from the circulation of the system, thus as it may look impressive, in all reality Invest 97 is still quite disorganized. The graphics shows above are a depiction of the current wind shear over Invest 97 and the rest of the Atlantic. Right now wind shear is exceeding 45 knots over the invest, which for a tropical system of any strength is very significant and very inhibitive to development.Looking at the rest of the gulf the wind shear relaxes somewhat, but never goes away. However, the atmosphere is not a stationary object and the wind shear will begin to outrun Invest 97 by Friday and by the weekend the shear should be relaxing considerably, which would help the invest begin to develop. The Gulf of Mexico, with the exception of the most southwestern portions, have been calm for several...

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Chasing Oklahoma in July – Who Thought?

Good Morning, It’s just before the despicable hour of six and the sun has not even begun to rise as of the time of this typing. Not exactly the way I wanted to start off the chase, but hey, I can’t sleep so what am I going to do? Checking data this morning the first thing that pops up is that there is an extensive amount of precipitation and cloud cover over Texas and Oklahoma this morning. Most of Oklahoma has some light precipitation this morning while more vigorous convection has developed over West Texas in the past hour, as shown by the brighter colors in the Infrared map. That convection, and associated cloud cover, will most likely impact areas along and south of Oklahoma City as the morning goes on. That precipitation shield is associated with a disturbance that will move into Oklahoma today and help spark off more convection. With situations such as this the models have a very hard time keeping up with current trends, thus their projections for later periods are usually out of whack. The same applies to this case, thus It’s going to be more of a hand-analysis type of day to determine where the boundaries are along with the stationary front. Low Level Shear is weak but stationary fronts have a tendency to locally enhance the shear, so if any storm can...

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Chasing Tomorrow?

Good Evening, First off I did end up playing with something I should not have played with again so I’m in the process of getting everything back online. Good thing about this though is I’ve become quite efficient at doing that and every time I end up putting up new content it is better then the last. Still though I’ve made backups so that will not be a problem again. Now onto the topic at hand. Starting several days ago the GFS began showing a dip in the jetstream to the south. That is unusual, but not unheard of for this time of year. By July the jetstream is usually in North Dakota into Canada, but it’s going to dip south for a few days. Tomorrow the winds at 500 MB will be 30 to 40 knots over a majority of Kansas. Normally the winds at 500 MB will be coming from the west or southwest, but in this case they will be coming in from the Northwest. This is refereed to as a Northwest Flow Event. Normally storms in this environment are quite HP but also are slow movers. North Texas had several days under a northwest flow back in June of 2009. I captured a tornado on June 12, 2009 out in Palo Pinto county from a HP storm under this type of setup. [caption id=”” align=”aligncenter”...

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