I just made that up for "I Decline to Ponder / Pontificate". That's how I feel about the current system to our south. The storm system is so complex that forecasts range from all rain to nearly six inches of snow and everything in between with a mix of rain, sleet, snow and ice.
Why is it so complex to figure out? Because it is a cut-off low pressure system that is cut off from the jet stream or an attached cold front, it can meander in just about any direction it wants to. Yeah, it sounds like it has a mind of its own. Usually the upper level jet stream or, a warm front (mainly in summer) or, a cold front are the main drivers that push storms from west to east and south to north. That will eventually happen in this case but not before it wobbles around. As is wobbles around, it changes the temperature and precipitation on the east and west side of the wobble. Okay. I hope that's helpful.
Here's the current thinking from the NWS:
.SYNOPSIS...
Issued at 219 AM EST Wed Nov 14 2018
High Pressure in place across Illinois will push across Indiana
today bringing dry and cool weather today.
Strong Low pressure is expected to build across the deep south
tonight and push north across Kentucky and Tennessee. As the low
approaches...wintry precipitation is expected to across Indiana on
Thursday. This will result in some accumulating snow on Thursday
along with the possibility of some freezing rain.
The Low will quickly depart on Thursday night...ending the
precipitation and bringing dry weather for Friday and Friday
Night. Another weak cold front will sweep across Central Indiana
on Saturday which could bring more light precipitation along
followed by more cold weather for Sunday.
&&
.NEAR TERM /Today/...
Issued at 1041 AM EST Wed Nov 14 2018
Not much change to ongoing forecast. Did increase cloud cover
across the southern half of the forecast area to account for a
more invasive shield of mid to upper level clouds as the upper-
level system over the Arklatex region heads our way during the day
today. The northern edge of the mid to low deck associated with
this approaching system is currently located over southeast
Missouri into southern Illinois and southern Indiana. Expect the
cloudiness to continue across much of central Indiana
today...especially over the southern half of the area. Minor
changes to temps but kept highs in the middle 30s going...as
there was no appreciable change to the forecast that would warrant
an increase or decrease there.
&&
.SHORT TERM /Tonight through Friday Night/...
Issued at 219 AM EST Wed Nov 14 2018
The GFS and Nam suggest a strong Cut-off Low lifting out of the
plume of tropical moisture to the south and pushing toward and
across Tennessee and Kentucky late tonight through Thursday.
Strong indicators of plentiful moisture appear in place given the
flow aloft. Excellent forcing appears in place as the low
approaches and forecast soundings respond showing deep saturation
through the day on Thursday. Top-down methods suggest some
freezing rain will be possible on onset...particularly across the
southern half of the forecast area as moisture arrives. Given the
favorable expected path of the upper low...confidence is high for
precip however confidence remains low on amounts and type. At a
minimum...winter weather advisories will likely be needed and
possibly more across the south where ice may mix in. Thus will
stick close to the forecast builder blends pops tonight but trend
toward 100 pops on Thursday. Furthermore will trend lows warmer
and highs cooler than the blends given the expected clouds and
precip.
Best forcing exits the area quickly on Thursday night as the
upper low departs the area to the northeast. Dry air arrives
overnight as the Low reaches the middle Atlantic states. Although
some lingering precip could still be present the first few hours
after 00Z...the trend will be toward drying out. Forecast
soundings show drying and subsidence within the column. Thus may
keep a few pops across the east as the system departs but will
overall trend toward a becoming partly cloudy and dry forecast.
Given the possible snow on the ground and expected cold air
advection will trend lows cooler than the blends.
High pressure over the deep south on Friday and Friday night will
nose north into the Ohio Valley. Forecast soundings and mid level
guidance shows dry air and subsidence. Will trend toward a partly
cloudy day and temps at or below the model blends.
&&
.LONG TERM /Saturday through Tuesday/...
Issued at 232 AM EST Wed Nov 14 2018
Ensembles are in good agreement in keeping broad upper troughing
over the Midwest and East Coast during this period. There are still
timing differences among the individual members as to a weak short
wave trough that is expected to move through the area over the
weekend.
There continues to be a rather wide spread among the ensembles with
respect to the timing of the precipitation threat with the weekend
disturbance, anywhere from during the day Saturday to as late as
Sunday night. Don`t see any real trends yet one way or another,
so for now will go with chance PoPs for light mixed precipitation
at times from Saturday through Sunday night. Precipitation amounts
with this system still look to be on the light side.
