***Severe Weather March 2018***

Thread starter #1
Today will be interesting later in the afternoon and overnight for the states to our west. This will transfer over to N. Ga overnight and the entire state through Sunday night. The energy potential will be higher to our west but still have significant dynamics to support strong Thunderstorm development as it moves through Georgia on Sunday.

Here is a blog for today and I will update it when it comes available for tomorrow.

Thread starter #3
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0400 AM CDT Fri Mar 16 2018

Valid 191200Z - 241200Z

Numerical models are in relatively good agreement with the movement
of a shortwave trough from the southern Plains across the lower MS
Valley on Monday, with a surface low moving from AR into TN during
the day or evening. The ECMWF is faster/farther east with the low
than the GFS, which lends uncertainty. However, the risk area can be
adjusted in later outlooks.

On Monday Day 4, a cold front is forecast to stretch roughly from
middle TN southward across MS by 00Z Tuesday, continuing eastward
across AL and into GA by Tuesday morning. A warm front will also
lift north across the region, stretching from northern AL into
central GA at 00Z. Dewpoints in the 60s F and cool midlevel
temperatures will result in around 1500 J/kg MUCAPE, with strong
deep-layer shear profiles supporting organized convection. Low-level
shear will be maximized near the warm front, and forecast wind
profiles do support supercells. Conditional on storm mode, a tornado
threat may exist. The northern threat into TN will depend on
instability, but otherwise the synoptic setup appears most favorable
there. To the south, instability will be much greater and one or
more clusters of storms are expected to spread across AL and GA with
damaging winds likely given strong mean wind profiles.

Beyond day 4, severe weather is not expected.

..Jewell.. 03/16/2018

Thread starter #4
I am expecting the NWS SPC to upgrade the severity of Monday into Tuesdays potential tomorrow. The 700mb jet is projected to lay out perfectly with 60 to 65 kt winds out of the SE with surface winds weaker out of the south. MUCAPE will be in the 3500 Jkg range, which is strong. You start approaching the 4000 Jkg range and it becomes a potentially dangerous situation. These maps are from the NAM. There is a good deal of disagreement still on timing of the event between the NAM, GFS and EURO. The METS in Alabama are using some strong language for their Sunday night into Monday potential forecast so this is something I will definitely be monitoring.

Thread starter #5
As suspected and stated earlier the NWS SPC has upgraded our potential, particularly for NW GA for the upcoming system that will be effecting our weather Monday into Tuesday. Now that they have had a good look at the available energy this system has. With daytime heating and the low tapping into the Gulf of Mexico moisture today should be quite active to our west. We will continue to monitor the development of our potential risks and update everyone accordingly.

The maps below define percentages of severe weather and the third is todays thunderstorm risk percentage area, fourth is the GFS Supercell Composite for 21z Monday (4pm).

From the NWS this is the discussion valid Monday 19th:

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Sun Mar 18 2018

Valid 191200Z - 201200Z




Tornadoes, damaging wind and hail are expected across parts of
Middle Tennessee, much of northern Alabama, and northwest Georgia. A
strong tornado or two is possible during the late afternoon. Severe
wind is also possible into northern Florida.

A compact shortwave trough will move quickly from AR Monday morning
to the TN Valley by 00Z Tuesday, with a slight deamplification. Wind
profiles will increase throughout the day, with cooling aloft
overspreading KY, TN, and northern AL/GA. At the surface, low
pressure will move from OK across TN, with a cold front extending
from Middle TN across central MS by 00Z Tuesday. Ahead of the front,
dewpoints into the lower 60s F will reach as far north as TN, with
mid 60s F over AL and GA. To the east, a warm front will lift across
northern AL and GA during the day, allowing for destabilization.
Severe thunderstorms are likely near the surface low and along the
cold front, with the primary threat area from Middle TN into
northern AL and northwest GA during the afternoon.

...Middle TN into northern AL and northwest GA...
Scattered showers and a few thunderstorms may be ongoing Monday
morning from TN into northern GA associated with warm advection near
the warm front. This activity should lift north, allowing for
heating farther upstream across western TN and MS. If early day
storms are more widespread than expected, this could have an impact
on the position of the main threat area later in the day.

A minor capping inversion will be present around 850 mb according to
forecast soundings. This will keep the warm sector free of
additional precipitation contamination. Lapse rates aloft will
steepen as the shortwave trough approaches, and wind profiles will
strengthen creating a favorable setup for tornadic supercells. The
area of strongest lift, shear and instability will exist over a
relatively limited in area, but supercells that do occur will have
significant tornado potential, along with large hail. The eastern
extent will be limited by a wedge of cooler air from eastern TN
across northern GA. Storm density will likely decrease across north
central AL, farther away from the main area of lift, but a
conditional threat of supercells capable of a tornado or two and
large hail will exist. This threat may spread across eastern AL into
western GA during the evening, as warmer air spreads east resulting
in surface based instability.

...Fl Panhandle into southern GA...
Although well removed from the shortwave trough to the north, a
broad belt of strong flow aloft will encompass the Southeast, with
deep-layer shear profiles favorable for severe storms. Mid to upper
60s F dewpoints will result in favorable thermodynamics to support
strong to severe storms. Storms are expected to form over the FL
Panhandle into northern FL by early to mid afternoon, spreading into
southern GA. Although low-level shear is not particularly strong, it
may be sufficient to support a tornado or two, with the primary risk
being damaging winds.

..Jewell.. 03/18/2018