Meteorologist Dave Nussbaum's Weather Blog

Tropical Depression 9 has strengthened into Tropical Storm Hermine with 40 mph winds. It is producing more convection today and is a little better organized.  This is due to less wind shear moving over the system.  You can see outflow on the satellite images, and this is a sign that the storm is getting better organized.  Hermine will continue to slowly get stronger today as it moves over very warm water temps. in the upper 80s. with only moderate wind shear over the system.  It is currently stationary, and that is ok.  This just lets the trough of low pressure dig deeper across the Eastern U.S., and it will be pulling Hermine to the NNE later this evening.   The trough of low pressure over the Eastern U.S. and will continue to pull Hermine to the north  and NE through Thursday.  At the same time, a cold front will also be moving south with the trough to help send Hermine away from Louisiana and into the Florida Panhandle.  While this i...

Tropical Depression 9 remains disorganized this morning with 35 mph winds, but convection (thunderstorms) are increasing on the eastern and southern side of the low when you look at the latest satellite images.  It is still battling wind shear and dry air to the west of the low, but that will be changing during the next 24 hours.  TD 9 will be moving over very warm Gulf Waters in the upper 80s. This will help to make it a little stronger today, and the forecast is calling for it to become a tropical storm with 40 mph winds. It will likely get the name Hermine (assuming TD 8 doesn't' strengthen first off the North Carolina Coast). On Wednesday, the wind shear will be more relaxed, but the system will still be battling the dry air west and NW of the low. However, since the wind shear will not be as strong, it is forecast to strengthen during the day with winds getting up to 45-50 mph.  It will turn to the north as the trough of low pressure over the Eastern U.S. pulls i...

Tropical Depression 9 still remains disorganized in the far Southeast Gulf of Mexico.  It is still battling wind shear and dry air thanks to an upper-level low over the NW Gulf. This is the same upper-level low that brought Louisiana rain the last few days. Winds are sustained at 35 mph according to the Hurricane Hunters. Due to the disorganized nature of TD 9, I'm only expecting it to only get a little stronger in the next 24 hours.  It will be moving into warm Gulf Waters and the wind shear will be a little less than it is right now. Forecast now calls for it to become a minimal tropical storm on Tuesday with 40 to 45 mph winds. It will likely get the name Hermine (her-MEEN). I'm still expecting the upper-level area of high pressure to move toward the Plains States. At the same time, a trough of low pressure will be over the East Coast, and it will send a backdoor cold front down to the Southeast U.S. As TD 9 moves into the Central Gulf, it will be pulled north by the ...

Tropical Depression 9 is looking very ragged this morning with 35 mph winds and it is moving to the W at 9 mph.  Looking at the latest satellite and radar data, the bulk of the clouds and rain are SE of the center of circulation. This is due to wind shear blowing the storms in that direction.  The depression is still ingesting some dry air too.  The wind shear is coming from an upper-level low that is sitting over the NW Gulf just off the Texas Coast. This is the same upper-level low that brought us some rain over the weekend. These factors are preventing TD 9 from getting stronger - for now.   The forecast models are showing TD 9 moving to the WNW slowly today without getting any stronger.  Then on Tuesday, it will move over more warm water in the upper 80s, and the wind shear is expected to relax a little as the upper-level low moves into Texas.  At this time, TD 9 is expected to get a tad stronger and become a tropical storm (either Hermine...

Hurricane Hunters have found that Invest 99 now has a well-defined center in the Florida Straits, and  there has been a significant increase in showers and thunderstorms today.  Therefore, it has been upgraded to Tropical Depression 9.   Over the next 24-48 hours, TD 9 will be moving through only a somewhat favorable area for additional development over the Eastern and Central Gulf of Mexico.  It will still encounter wind shear around 15 knots, and that is enough to prevent it from getting any stronger. Then in about 2 days, the wind shear will be less, and this will allow for TD 9 to get a little stronger. This is where it could become a tropical storm (likely Ian, Hermine will likely form with TD 8 before TD 9). However, the forecast models are not in agreement at this time. The Euro just dissipates it, but the GFS and other models have it developing into a likely tropical storm in 4 days. The NHC is basing its forecast track off mainly the Euro as of now...

Invest 99 is now sitting just north of Central Cuba.  It is a little better organized today compared to yesterday as more showers and thunderstorms have developed around this system.  However, it overall is still disorganized.  It is still fighting off wind shear and some dry air.  Invest 99 is moving to the WNW and will enter the Florida Straits on Sunday.  NHC is giving it a medium chance for development in 2 days and in 5 days.  The Hurricane Hunters are scheduled to investigate the system on Sunday. Once it enters the Florida Straits, the system will have slightly better conditions for development.  Then it is forecast to continue to move to the WNW into the Eastern Gulf of Mexico on Monday.  At this point, there will be better conditions for development where water temperatures are in the upper 80s.  However, the forecast models are still very uncertain of where Invest 99 will go.  The spaghetti plots show it could go anywhere f...

Invest 99 remains poorly organized on this Friday Morning.  It remains a broad area of low pressure that is associated with a tropical wave located near Eastern Cuba. This low is producing only a few showers and storms to the south and east of the of the center.  This system continues to fight wind shear and dry air.  Conditions are not expected to get any better today as it moves to the west around 13 mph.  If it continues to move to the west, it could get ripped up over the mountains of Cuba. Also, the shear would have to relax for it to develop further.  As of this morning, it does not look like this will happen today.  NHC is giving is a low chance for development in 2 days and a medium chance in 5 days. The low is forecast to continue on a W-NW track this weekend, and there is a chance it could get into the Straits of Florida and the Gulf of Mexico as a tropical wave.  If it does get into the Gulf, then conditions could be a little more f...

We are closely watching the slow development of Invest 99.  Hurricane Hunters flew into it this morning, and good news...it is still not developed!  Actually, it looks worse than it did 24 hours ago.   It is a broad area of low pressure - meaning a large area of circulation, and it continues to lack a well-defined center.  The system remains disorganized as it sits north of the Island of Hispaniola.   Most of the storms are now absent from the system.  The nearest ones are over the Dominican Republic and Haiti, not near the center of lowest pressure thanks to moderate wind shear and dry air aloft. You need the storms to be close to and around the center for it to develop. If it can get better organized, there is a chance it could become a tropical depression, but it does not look like that will happen for at least a few days as it quickly moves to the WNW at 21 mph.  Another thing you typically need for development is for the movement to ...

I'm still keeping a close eye on how Invest 99 develops.  Hurricane Hunters find that #Invest99 still lacks a well-defined circulation, but it's producing tropical-storm force winds in squalls over the Northern Leeward Islands. However, this system could become a tropical storm or tropical depression at any time during the next couple of days. Conditions could become more favorable for development when the system is near the Bahamas by the weekend.  At the moment it is a broad (large) area of low pressure. If there is evidence that it does develop a closed low, then we could have a tropical depression or storm later today or Thursday.   It is currently going through some dry air and wind shear, so the conditions are not very favorable for significant development over the next couple of days.  Right now, the bulk of the thunderstorms are not wrapping around anything.  They are getting blown off to the SE.  However, in the next few days the system will...

I'm sure you have seen or heard talk today either on air or across social media sites about a possible tropical system (Invest 99) in the Gulf of Mexico next week. What you may have seen is just one run of the European Forecast Model. The model is developing a possible hurricane from poorly organized tropical wave as of this writing, and moving it from the Bahamas into the Gulf of Mexico.     ECMWF 12Z Tue., Forecast time: 7 AM, Wed. Aug 31 Currently, this tropical wave is located a couple hundred miles from the Lesser Antilles. It is getting better organized, but Hurricane Hunters flew into it today, and found the wave elongated (stretched out) with a poorly defined circulation. It is fighting off dry air and some wind shear. However, it is forecast to become better organized over the next few days as it moves NW over warmer waters and less wind shear. It will head toward the Leeward Islands, Greater Antilles and the Bahamas. Please know that tropical systems ...

FLASH FLOOD WATCH FOR ALL OF SE LOUISIANA FROM NOW - SATURDAY 7AM.  AROUND 7-10" WITH HIGHER AMOUNTS POSSIBLE There is a High Risk for flooding throughout the day on both sides of the lake.  The area of low pressure is located over South Mississippi and it is slowly moving to the west.  We will continue to see bands of heavy rain and storms wrap around it all day.  Additional rainfall totals could be around 4-6"+ today.  This would cause more flooding issues on the Northshore and Southshore.  Watch for rapidly rising streams, creeks, ditches and other low-lying areas.  High temperatures will only be around 80.   More heavy rain is expected tonight on both sides of the lake as the low moves to the west of us.  Again, flooding is likely!  Lows will be in the  70s .   The low will continue to slowly move to the west this weekend, and we will gradually see the chance for rain go down to 60% on Saturday and 50% on ...