Saturday Forecast
Great news: today is the last full day of summer! I’m eager to say so long to one of the hottest summers on record in Middle Tennessee. Temperatures this morning are mild, in the 60s and 70s at wake-up time. Sun will mix with a few clouds from time to time, especially this afternoon. Highs today should peak in the upper 80s to near 90 degrees. The humidity will be noticeable for the next several days. Remnant moisture from Tropical Depression #10 will combine with a slow-moving front to bring small rain chances for most of the upcoming work/school week. Check out the seven day forecast: even though I’m mentioning rain from Monday through Friday, the chances are only between 20% and 30%.
Fair Weather Clouds
Some fair weather cumulus clouds have developed across Middle Tennessee this afternoon, in response to moisture streaming northward from Tropical Depression #10 down in the Gulf. The News 2 City Cam shows the clouds are “flat” and won’t produce a drop of rain. We expect much of the same on Saturday. On Sunday, the moisture will be a bit “deeper” as the tropical system lifts north, but we’ll keep rain out of the forecast through the weekend.
Satellite loop.
Upgraded to Tropical Depression #10
According to the National Hurricane Center, satellite imagery suggests that the subtropical feature in the northern Gulf of Mexico has acquired enough tropical characteristics to be upgraded to Tropical Depression #10.
Six of one, a half dozen of another. Folks from the Panhandle to Louisiana will still contend with several inches of rain, gusty wind and the possibility of an isolated tornado between now and Saturday afternoon.
As I pointed out yesterday, this system was spawned from the same upper level disturbance that brought us some sprinkles last Sunday morning. What goes around comes around: we’re hopeful for scattered showers on Monday and Tuesday as the remnant moisture approaches our area.
Current maximum sustained winds are 35 mph. If they increase to 39 mph, Tropical Depression #10 will be upgraded to Tropical Storm Jerry. The National Hurricane Center expects that to occur later today or tomorrow.
Subtropical Depression #10
The National Hurricane Center just issued their first advisory for Subtropical Depression #10. A tropical system has a warm core and tight circulation; this system remains loosely organized with a cold core (hence the “subtropical” designation). Nevertheless, rainfall totals of 2″ to 4″ (isolated 6″ amounts) in addition to 1′ to 2′ coastal storm surges will keep folks from the Florida Panhandle to Louisiana on guard today through the weekend. Isolated tornadoes will also be possible.
Wind shear will remain low and water temperatures are warm in the northern Gulf, so some strengthening is possible over the next 24 hours. A landfall is projected for Saturday PM in Mississippi or southeast Louisiana, but the exact location is unimportant because of the system’s loose organization. If the winds increase, the system will be “upgraded” to a subtropical storm or a tropical storm, which would be named Jerry. (Seinfeld, Garcia, or Barlar?)
Summer Continues
The same weather pattern that gave us 100 degree weather in August is giving us 90 degree weather in the last few days of summer. The only thing keeping us from hitting 90 today will be some afternoon clouds. A southeast wind today with more clouds down in the Boro’, Shelbyville and Manchester than in Springfield and Clarksville by later today. It appears that warm weather will continue over the weekend with rain chances holding off until Monday. Below are the forecasted highs for today:
Something in the Gulf?
Something is brewing in the Gulf of Mexico (visible satellite loop) and may end up between New Orleans and Panama City this weekend. What!? Normally, that statement would cause quite a commotion. Truth be told, we’re not too worried about it. Why?
Here’s what the National Hurricane Center has to say about this “non-tropical” system:
SURFACE OBSERVATIONS INDICATE THAT A WEAK LOW PRESSURE AREA HAS FORMED IN THE EASTERN GULF OF MEXICO IN ASSOCIATION WITH AN UPPER-LEVEL LOW. SHOWER ACTIVITY WITH THIS NON-TROPICAL SYSTEM REMAINS LIMITED AND DISORGANIZED. HOWEVER…THIS SYSTEM HAS THE POTENTIAL TO ACQUIRE SUBTROPICAL CHARACTERISTICS LATER TODAY OR TOMORROW AS IT MOVES WEST-NORTHWESTWARD OVER THE WARM WATERS OF THE GULF OF MEXICO.
Below I’ve posted three weather maps (the 500 millibar level up around 18,000 feet) that help explain why the system in the Gulf isn’t going to wreak too much havoc, just bring some rain to the impacted areas.
The first map is from last Sunday, September 16th. The red “blob” moving across Tennessee is a weak upper level disturbance that prompted a few isolated sprinkles early in the morning. Remember?
By Monday afternoon (three days ago) the disturbance had dropped southeastward and was over Florida. The upper flow was weak, so the upper level “ripple” just hung over the Sunshine State, bringing clouds and wet weather.
The final map is valid this morning (Thursday September 20th). The upper disturbance has intensified a bit, and prompted surface low pressure to develop in the northeast Gulf.
As I mentioned, we’re not super-worried about this feature causing major problems along the northern Gulf Coast (where a “landfall” of sorts is possible by Saturday). As New Orleans natives, Davis and I are pretty sensitive to anything south of the Big Easy. It will bring rain and breezy conditions, and strengthening is possible due to the fact that the Gulf waters are warm. But this isn’t a big, beefy tropical wave that rolled off the coast of Africa, like Dean or Felix. We’ll watch it, of course, and keep you posted. If this thing organized into a tropical storm or minimal hurricane, it would be called Jerry. When it comes to the tropics, it ain’t over until it’s actually over…so check back with us.
Of greater import to Middle Tennessee, the remnants of this system will try to head north early next week, bringing us a chance of showers on Monday, Tuesday and Wednesday. We need it!
Dry Again, Warm Again
We’ll have highs in the upper 80’s this afternoon with lots of sunshine in store for middle Tennessee again. A northeast wind will again hold down dewpoints to the low 50’s this afternoon making for a relative humidity in the 30% range. The dry weather continues tomorrow as well as we close out the last week of summer (the fall equinox is Sunday); this how Predictor looks tomorrow afternoon. Rain chances are likely to hold off until we get into Monday.
Mornin’ Jack!
And all our other early bird weather checkers here at the News 2 weather blog!
Looks like another day of sunshine and 80s after a cool start around 60.
Update on “Subtropical” Low Over Florida and Our Rain Chances
Since things are pretty stagnant this week, we are looking ahead 5-6 days for our next rain chance, which we really need.
The newest AVN/GFS model run continues to show this system moving west northwest across the northern Gulf, possibly becoming a tropical storm (at worst). It then curves ashore near Louisiana into Arkansas and northeast Texas before turning eastward ahead of a cold front next week. If that verifies, our first decent rain chances come next Monday and Tuesday, although there may be an isolated shower or two on Sunday.
The details of this are sure to change somewhat, but this is the 3rd AVN/GFS model run in a row that shows this trend.
That will be a full 10 days since the last rain from Humberto. Keep your fingers crossed.
By the way, what is a “subtropical low”? Regular mid latitude lows are “cold core” with cold air in their centers. True tropical systems are warm core. This one is cold core. These types of systems can transform to warm core, but it can take time. It can take several days of convection (t’storms) injecting warm air aloft into the center. That is why I say that it will only reach tropical storm strength at worst.
Fine Weather Continues…Unless You Want Rain
We’ll continue to see dry weather across middle Tennessee and southern Kentucky. Highs will again be above normal for the time of year; into the upper 80’s (a typical high would be around 80). We are watching the Gulf of Mexico to see what happens there heading into the weekend. A tropical wave bringing big rains to eastern Florida will move over the warm gulf waters by late Thursday and possible become Tropical Storm Jerry. By Saturday most forecast models put Jerry into New Orleans or close by. That would increase our rain chances by Sunday and Monday but we would start seeing some of the cloud cover (if it does indeed become a strong T.S. or minimual hurricane) by late Friday or Saturday. Right now we’ll hold off on rain chances around here until Monday as the humidity increases over the weekend. Below are the forecasted highs for today:
