Saturday, August 4, 2012

Tropical Storm Ernesto 8:30 PM CT Forecast

8:30 PM CT
August 4, 2012

I am projecting Tropical Storm Ernesto to move on a west-northwest path across the Caribbean as a tropical storm before briefly gaining Category 1 strength prior to making a first landfall on the Yucatan Peninsula.

Following that landfall, Ernesto will likely enter the Gulf of Mexico as a tropical storm, but quickly strengthen back into a hurricane. As rapid strengthening occurs, model guidance and myself find it possible that Ernesto may briefly reach major hurricane status.

Because model guidance only carries Ernesto to roughly a day after exiting the Yucatan Peninsula, a stronger hurricane than what I am projecting may be in store.

Upper level winds look to be on the downturn when Ernesto ejects from the Peninsula, and this could help development in Ernesto after it begins its journey in the Gulf of Mexico.

It is to be noted that the track I am showing will likely only work if significant strengthening occurs. Should strengthening occur slower than what I am thinking, the tropical cyclone will likely make landfall in northeast Mexico or extreme southern Texas.

More model watching is needed for me to be confident in this forecast, especially the portion of the forecast in the Gulf of Mexico. Nonetheless, close monitoring is needed for the Gulf Coast.


TS Ernesto Weakens as Dry Air is Pulled In

Tropical Storm Ernesto has run into drier air, and this has shown on satellite imagery as damaging the western flank of the system.

Water Vapor imagery indicates a wide area of dry air just ahead of Ernesto, and this is being enveloped into the system. Ernesto itself is comprised of a big blob of storms with a lot of debris clouds overspreading miles and miles away from Ernesto's core.

A loop of Ernesto shows the sudden diminishing of showers and storms in the storm, which will only continue to hamper further development until all of the dry air is out of the way, and this could take some time.


Active Northern US Weather Pattern to Continue

The active weather pattern that has plagued the Northern US for over a week now is to continue for time to come as the result of a trough in the Gulf of Alaska and a ridge in the Southwest.

A low pressure system in the Gulf of Alaska is poised to settle in over the next few days. Common to what has been recently observed, pieces of energy will break off of this parent disturbance in the Gulf of Alaska and move eastward.

As they move eastward, a ridge of high pressure extending from the Southwest into Canada will force the pieces of energy northward over the high pressure system. As the disturbances move south again after moving over the ridge, they will move south as the high pressure system's influences end.

The jet stream will help to force these pieces of energy south into the Northern Plains and Upper Midwest, where showers and storms may be initiated in the mentioned regions, similar to what is ongoing today (August 4) and what has happened in the past couple of weeks.

Long range forecasts have this low pressure system in the Gulf of Alaska breaking down, but long range forecasts are notorious for being a long ways off of what happens, so take that for what it's worth.


Another Severe Weather Threat Eyes Thursday in Great Lakes

A severe weather threat similar to today's ongoing severe weather threat is being forecast for this upcoming Thursday.

The GFS is forecasting a positively tilted trough to push into the Upper Midwest on Thursday, creating mid level winds similar to what is being observed today in the Upper Midwest. The trough appears to be pushing on the ridge of high pressure that will be in place over the Southwest. This pushing will create friction between both atmospheric factors that will increase upper level wind speeds and increase the potential for some stronger storms in those areas.

There remains a difference between this forecast and today's event. In today's event, the trough is digging deeper and producing stronger winds. More importantly, the system is negatively tilted today. Negatively tilted troughs are more conducive for severe weather, which is being shown in the Midwest at the time of publishing.

That said, I believe that while there is a severe threat for the Midwest and Great Lakes on Thursday, it likely will not be as significant as what we are seeing today.


TS Ernesto Aims For Gulf Coast; Florence to Dissipate Soon

Tropical Storm Ernesto

TS Ernesto is currently within the eastern half of the Caribbean and moving westward, in a motion that will eventually turn northwest. Ernesto is expected to strengthen into a hurricane and landfall on the Yucatan Peninsula in Mexico. Considering it will only be a hurricane for a short time, I do not believe that this landfall will be a significant one. 
Following the first landfall, I believe that Ernesto will emerge in the Gulf of Mexico as a tropical storm after its bout with land. However, due to the relatively untouched Gulf waters this season, there should be enough energy for potentially rapid strengthening into a hurricane that, according to my calculations, should hit Texas or Louisiana. That said, anyone in the red 'Risk Area' should be on watch to prepare supplies for a tropical system. Those in Texas and Louisiana should prepare for a tropical cyclone impact now. Remember: Better safe than sorry!

Tropical Storm Florence

Florence has been quick to form, but will also be quick to dissipate, as the system enters an area with heavy shearing and moderate lower level winds. Florence should dissipate in a few days.