Tropical Storm Debby Still Dumping Rain on Florida...

Tropical Storm Debby continues to dump heavy rain on Florida...a trend that is likely to continue today. At 7am CDT, the center of Debby was located about 90 miles South/Southwest of Apalachicola, Florida.  The "official" National Hurricane Center advisory states that Debby is stationary, but satellite imagery indicates that it is drifting East/Northeastward very slowly, a trend that has continued since yesterday.

Quite a bit of dry air has been drawn into the system in the last 6-12 hours, which has resulted in a general decrease in the coverage and intensity of the rain over Florida.  Daytime heating today will likely cause an increase in thunderstorm activity, some of which will produce locally heavy rainfall.

If Debby doesn't reorganize during the day today, and the dry air continues to intrude into the system, she could weaken to a Depression before making official landfall in Florida.  (Remember that landfall occurs when the center of the system moves onshore - which is kind of irrelevant in this case because the effects of Debby have been felt in Florida for days now, and will continue until she moves back out over the Atlantic).

The latest Hydrometeorological Prediction Center (HPC) forecast calls for an additional 6-12 inches of rain across northwest Florida and the panhandle.  Locally heavier amounts are also possible in stronger storms:

The steering currents around Debby continue to be rather weak.  If she does not become fully ingested by the trough of low pressure over the Eastern U.S. (which is what caused her Northeast turn yesterday), she could continue to wobble around the northeastern Gulf of Mexico, hammering Florida with more heavy rain through Wednesday or possibly even Thursday.  Time will tell for sure, but folks in this region should continue to take precautions, especially if you live in a low lying or flood prone area.

The official NHC track calls for Debby to move slowly Northward, making landfall somewhere in the panhandle of Florida.  I am still of the opinion that a more Northeastward drift is likely (and that appears to be what we're seeing currently on satellite imagery), which would mean more of a northwest Florida or Florida bend landfall.  Again, this is really irrelevant, as the heavier rain and thunderstorm activity will continue to spread across Florida on the Eastern side of the system anyway.

The main thing to watch now is how quickly she'll move ashore and eventually out of the region, giving Florida a much needed break from the rain.  I think the next 12 hours are key.  If a decent move (and I mean even just 5 or 6 mph) to the East or Northeast is not noted, I think the chances are she will continue to spin around the northeast Gulf for a few more days, dumping more rain on Florida.

For additional details including the latest satellite and radar imagery and loops of this system, please visit this dedicated page on our sister site, WeatherGuidance.com.

For more information, including "live blogging" during rapidly changing weather events, please be sure to follow me on facebook and/or twitter:

 

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Update on Tropical Storm Debby

As of 1pm CDT, the center of Tropical Storm Debby was located about 175 miles East/Southeast of the mouth of the Mississippi River, and moving Northeast at 6 mph.

Debby has been moving toward the Northeast for the last 4-5 hours, and there seems little doubt in my mind that it will continue to be drawn into the influence of the trough of low pressure developing over the Eastern U.S. and continue in this general direction over the next few days.  I would, therefore, expect a landfall (of the center) somewhere along the northwestern Florida coast late tomorrow or early Tuesday - but that is really irrelevant, as the state continues to be under siege by Debby right now (more on that in a moment).

The "official" forecast track from the National Hurricane Center continues to shift toward the East, but -at this time- still calls for a landfall in southern Louisiana later this week.  I suspect we'll continue to see the NHC shift their forecast Eastward over time, especially now that more and more of the major computer forecast models are now coming to the same conclusion:

As I mentioned above, regardless of the exact timing of the landfall of the center of Debby, Florida will continue to be hammered by high surf, dangerous rip currents, heavy rain and isolated tornadoes through at least most of Monday.

The latest rainfall forecast from the HPC is calling for widespread amounts of 6-12 inches across much of central and northern Florida through at least early Tuesday.  Localized amounts in excess of 12 inches will be possible in some areas, especially near and adjacent to the yellow shadings on the image:

Numerous tornado warnings have been issued today, and we'll continue to see spin-ups of tornadoes along the Eastern side of the thunderstorm activity associated with Debby through Monday.  While these tornadoes are typically short lived, if they happen to touch down in a populated area, they can still cause damage and injury.

Folks across the northeastern Gulf of Mexico, and especially Florida, southern Alabama and southern Georgia, should continue to monitor the latest information and forecasts concerning Debby.  If you are in central or northern Florida, including the panhandle region, and live in a flood prone area, please move to higher ground as quickly as it is safely possible and ride out the storm there.  Flooding and flash flooding, as well as the water inundation from the Gulf may indeed be the greatest threats with this system (other than the isolated tornado threat, of course).

I will make another post later this evening, or earlier if conditions warrant.  You may also wish to follow me on facebook or twitter (at the links below) for any short updates that I may post there from time to time as anything particularly interesting pops up.

For additional details including the latest satellite and radar imagery and loops of this system, please visit this dedicated page on our sister site, WeatherGuidance.com.

For more information, including "live blogging" during rapidly changing weather events, please be sure to follow me on facebook and/or twitter:

 

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Tropical Storm Debby Forms in the Gulf... Now What?

Above is a recent visible satellite image showing the center of Tropical Storm Debby (circled in yellow). At 4pm CDT, the center of the storm was located about 220 miles South of the mouth of the Mississippi River, and was drifting slowly Northward.

An Air Force Hurricane Hunter aircraft found a maximum surface wind of 50 mph in the Northeast quadrant of the storm this afternoon, prompting the National Hurricane Center (NHC) to declare the system Tropical Storm Debby. On a trivial aside, this is the first time in the history of the Atlantic basin that a 4th named storm has developed during the month of June.

As I mentioned in a facebook post earlier this afternoon, the declaration that this system is Tropical Storm Debby is the easy part.  The hard part is figuring out where she'll go next...

To give you an idea as to just how much of a challenge forecasters face with this one, take a look at the composite map below, which shows the various solutions of the "top" computer forecast models over the next 5 days:

We have an Easterly track, a Westerly track, a continued Northerly track, and almost everything in between.  That's enough to make even the most experienced forecaster pull his or her hair out.  So, I would advise you at this point to take any forecast track of Debby with a grain of salt.  For reasons I will attempt to explain below, it will be at least this time tomorrow before any reasonable level of certainty can be expressed in this situation, and that might even be a stretch as well...

The bottom line - at this point - is that if you live along the U.S. Gulf Coast, you will want to keep a close eye on the latest information concerning Debby over the upcoming days.

Getting back to the more recent developments and trends... Overnight last night and into the pre-dawn hours this morning, the center of Debby that we were observing yesterday dissipated and was replaced by the new center that we now see on the satellite image at the top of the post.  The "replacement" of the center of a storm is not uncommon, particularly during the infancy and mature stages of the system.  In this case, however, the replacement may prove to be very significant.

Why, you ask?  The new center is quite a bit further West than the one we were observing yesterday.  It could turn out to be just far enough to the West to prevent the system from being drawn up into the trough of low pressure that is forming in the Eastern third of the U.S. (the same trough that it  appeared would eventually cause the system to turn more toward Florida at about this time yesterday).

If the system fails to be drawn into the trough, it would not likely turn toward the East or Northeast.  That would leave two options:  a continued Northward movement toward the central Gulf Coast, or a Westward turn, toward the western Gulf Coast.

By this time tomorrow, we should have seen a turn toward the East or Northeast if this is going to take place.  If it does not, all bets are off, and folks from the central through western Gulf Coast will be under the gun.

The National Hurricane Center is currently siding with the European forecast models, and calling for a Westward turn and eventual track toward the Texas coast by mid-week next week:

While such a move is possible, I'm not completely sold on it at this point.

Check back tomorrow for more...and remember to watch for that Easterly or Northeasterly wobble between now and then.  If such a move happens, I think the Easterly track solution will win this one (as a disclaimer, I've been favoring that particular track all along).

For additional details including the latest satellite and radar imagery and loops of this system, please visit this dedicated page on our sister site, WeatherGuidance.com.

For more information, including "live blogging" during rapidly changing weather events, please be sure to follow me on facebook and/or twitter:

 

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