1. Sunday We will see a trough moving to the east as heights rise and ridging builds in. Once again a sign of more southerly flow, high pressure and a return to warmer than normal temperatures in the next few days. Sunday will also feature a week disturbance passing to our north which may increase high and mid level clouds. My thinking is for no precipitation from this. Model guidance is in good agreement for lows Sunday morning around 26 north to 29 south. A few spots may get slightly colder. I suspect MEX guidance may be slightly to cool for highs in a few spots and I’m going more in line with NAM/00z ECMWF temperatures with highs around 50 in the BG region to around 44 in northeast KY.
2. By Monday the high pressure moves east and we’re firmly in southerly flow. I’m going with similar reasoning for highs Monday WAA should allow temperatures to reach the low 50’s across most of the region. A closed low will begin to approach the region. The GFS and ECMWF both bring in precip by late Monday. I tend to agree with this over the NAM which has a typical slow bias when it comes to timing precip. By Tuesday morning the EC is most aggressive with around .25 qpf across far northern KY with little rain south of I-64 for BG. I like the model agreement south of I-64 of dry conditions lasting into Tuesday morning. Going more in line with GFS qpf with light rainfall of around .1 across the CVG region.
500 mb nam image of closed low
The closed low is over Texas with rising heights and WAA in our region. this closed low will move northeast into the Ohio valley Tuesday and Wednesday.
With this low moving northeast skies will be overcast with strong moisture advection into the region as well. This will lead to widespread showers from Tuesday afternoon into Wednesday morning. Total rainfall from .5-.75 could occur across the region. Light winds from Sunday through early Tuesday may increase to 10-15 mph for late Tuesday into Wednesday. Highs Tuesday should be in the 53-58 range with lows in the 40’s. With the southerly flow temperatures Tuesday night should be steady in the low 50’s with highs in the upper 50s’ in eastern KY with falling temperatures across Central KY.
– For Thursday I’m going to split the difference between the warmer EC and the cooler GFS with highs in the upper 40’s Thursday with high pressure building back in. This results in clearing skies. The GFS model brings a front through Friday with the region in a NW flow pattern while the Euro is much slower with the front leading to a few warmer than normal days. a GFS forecast would allow the next impulse to slide off the southeast coast with dry and seasonable weather while the EC would imply mild weather with another system cutting into the lakes. The CMC in more in line with the GFS and the EC ensembles are a little faster than the operational, the brand new 12Z run is faster as well. Either solution means a white christmas is not likely but it’s still several days away. For now will lean more toward the GFS. A system should from late week in the southern plains and move northeast meeting up with the front along the northern branch.
Here is my line of thinking on the long range a full post is below My winter outlook is on www.mitchg.wordpress.com for refrence.
I see no signs of a white christmas. The friday system appears to move out to quick before a brief cooldown of a few chilly days of normal to slightly below temps around then. The next warm-up is already in sight around the 27th. each warm period is twice as a long as warmer compared to normal than the cool-downs folks. LEX is 3*F above normal for the month. Jan may be better if the stratospheric warming works out. However like in most all la-nina winters Feb should feature a blowtorch of warmth. This winter will be warmer than normal and I’m finding it harder to figure out how we get 75% of normal snow this winter.
Forecaster: MWG