February 2023 Discussion

[Bgoney]

Agree , nothing has changed from a few days ago for a wintry event happening those first 5 days or so of the month. EPS is still on the scent of winter precip

eps.png

[tron777]

The above ^^^ looks more GFS like. I would expect the Euro to come north once we get a little closer. GEFS has a good mix of nothing, snow, and ice.

[tron777]

[tpweather]

Another nice video by Brian and just went over what we have talked about on here once again. Chances of precip next week and some will show up on models and others not until maybe a day or so before. Ground temps will be big with some of these waves even if the precip is light. Plenty of moisture available with the stronger high over Florida next week and this just pumps moisture into the southeast and some of that works into our area. Could we go without any precip next week and if the cold takes over of course but usually in these situations especially with strong ridging in Florida the cold only makes it so far south and also with several waves the cold tends to make baby steps because there is not that huge time between systems. If one of these waves get bigger than expected and we end up with a decent storm then the chances of the cold coming in after the storm is greater. Late next week models are trying to form that bigger storm and caution this is by no means a forecast but if one would develop then next weekend could be much colder than models are showing at this point.

[tron777]

We've certainly got some headaches next week for sure. Winter weather forecasting in the OV is some of the most challenging in the CONUS due to our geographical location. The WAA seems to always be an issue just as a cold high suppressing everything to our south, can also be an issue. It is so tough for everything to line up correctly. I've beaten this point like a dead horse over the years on our forum but it still rings true. We try our best on here to give out notices and heads up as early as we can. This is going to be one of those cases where we can't do that for risk of busting big time! The best we can do is to continue to monitor the trends on the modeling, talk about it, and then go from there. We need to share our ideas and thoughts and put our collective minds together to try and get it as right as we can.

[tpweather]

Les this will be fun over the next 10 days or so starting Monday.

[tron777]

Les this will be fun over the next 10 days or so starting Monday.

It will Tim. Everything from cold and dry, to ice / sleet to snow are all on the table. That SE Ridge is pretty strong so I am not betting on us being cold and dry. How many times this winter has the cold been overplayed on guidance? Tons! The nail biter storm came north after early on being modeled as an Apps Runner. This is a different set up of course, since we're talking overrunning here but the SE Ridge hasn't gone away by any stretch. We finally have some cold air pressing in to work with so it's a great set up for wintry weather for someone in the Ohio and TN Valleys. One final note... the orientation of the baroclinic zone also needs to be watched. If the cold is stronger and the SE ridge is more flat, you get a more west to east flow which could suppress things to our south. I'd like the baroclinic zone to be orientated more at an angle. You run the risk of too much warm air getting involved but that is always a risk when you want a nice wintry weather event. Rarely do we see non-complex events. It just doesn't work that way around here. Most of our wintry events are very complex and tough to predict as we've already discussed.

[tron777]

The light rain maker for Sat night and Sun is the first system to ride along the baroclinic boundary well to our NW. The first piece of the puzzle is how far south does it get after that system passes? That will impact where future waves ride along said boundary. Also the strength or amplitude of each wave makes a difference. A stronger wave will want to pull the boundary more NW while a weaker one would be more SE as the cold high would influence it more. These are a lot of reasons why next week is going to be so tough to predict.

[tpweather]

Les the difference this time compared to most of the winter is the south central ridge is not in play. That kept us from getting storms to dig in that area and work northeast. This will allow the cold to dig further south and hopefully east in time. The GOM is wide open compared to when we had the south central ridge that really is not talked enough during the winter and some winters it never shows up but this winter it showed up early and often but has broke down in the last week or so.

[tron777]

Les the difference this time compared to most of the winter is the south central ridge is not in play. That kept us from getting storms to dig in that area and work northeast. This will allow the cold to dig further south and hopefully east in time. The GOM is wide open compared to when we had the south central ridge that really is not talked enough during the winter and some winters it never shows up but this winter it showed up early and often but has broke down in the last week or so.

It certainly has broken down and the main players are the SE ridge over FL and how much it flexes with each wave passing thru the baroclinic boundary as well as the arctic cold pressing down on the NW side. These highs that are being modeled coming into play are no joke. Real deal cold air is ripe for the taking. We need to have the correct interaction between the SE ridge and arctic highs so the baroclinic boundary separating the two can deliver us wintry weather. As you said, no lack of moisture as the Gulf is wide open for business. Another term I probably overuse on here is TIMING but that is always so key in most weather situations both wintry and t-storms alike.

[tpweather]

Models and the upcoming pattern is one we usually see once or twice each winter. So we need to look at the normal bias for each model as well because with this set up we know certain things will happen especially several days out. The GFS will move systems to quickly, the EURO will keep energy held up too long and the CMC which I have been touting for this kind of pattern especially several days away as it seems to have a happy middle of the road take and then we adjust from there.

[tron777]

12Z GFS has the boundary stalling out in a nice spot after the weekend system passes. Sure, the Mon AM wave and Tues waves miss us. Modeling has been showing the stronger wave to be on 2/1-2/2 anyway which is what the GFS is doing here. The big arctic high is in a nice spot over MN and it moves East and doesn't squash everything. A very nice snowfall results for Cincinnati and NKY. I-70 Crew gets the shaft due to dry air eating away at the northern side. That is going to also be a risk for some areas of AV Land just as ice or rain could also turn out to be risks for the forum area. This is not going to be easy as we've been saying over and over again.

[BookNerdCarp]

We pulled out a two hour delay this morning

[tron777]

12Z Canadian stalls the boundary over us which is much farther to the north so Tues 1/31 is in play for snow and / or frozen precip. The 2/1 piece of energy slides a bit to our south as the boundary is now well to the south because of the 31st wave hitting us. Then a small break before the bigger piece of energy gets in here for GHD. which on this run gets suppressed to the south.

So the point here is how strong is each piece and where is the location of the boundary with each wave as well as the cold high pressing in the cold, arctic air? Models will continue to struggle for a little while longer as there are so many moving parts to this set up next week. A thread may need to be made for these events sometime over the weekend when I hope some of the questions begin to come into a little bit better focus.

[tron777]

We pulled out a two hour delay this morning

Ditto for Boone co. which I thought was funny but whatever.

[tpweather]

12Z Canadian stalls the boundary over us which is much farther to the north so Tues 1/31 is in play for snow and / or frozen precip. The 2/1 piece of energy slides a bit to our south as the boundary is now well to the south because of the 31st wave hitting us. Then a small break before the bigger piece of energy gets in here for GHD. which on this run gets suppressed to the south.

So the point here is how strong is each piece and where is the location of the boundary with each wave as well as the cold high pressing in the cold, arctic air? Models will continue to struggle for a little while longer as there are so many moving parts to this set up next week. A thread may need to be made for these events sometime over the weekend when I hope some of the questions begin to come into a little bit better focus.

No doubt Les and very fluent pattern and not like we are watching one big storm but several waves and we try and figure strength and position which this far out is almost impossible.

[BookNerdCarp]

We pulled out a two hour delay this morning

Ditto for Boone co. which I thought was funny but whatever.

I woke up...looked at the phone...went the window and was like WHAT?
But here in Georgetown they had a coating at just the right time.

[tron777]

12Z GEFS members... a few have a stripe of snow for us Mon morning but this is not a big signal as of yet. A somewhat better signal is showing up for Tues 1/31. An even better signal for 2/1 is in play where rain, ice, and snow are all showing up on the individual members. Sometime around 2/1 and GHD to me seems to be when the strongest wave tracks along the baroclinic boundary.

[airwolf76]

had a couple snow showers early this morning that left a heavy dusting in spots. we will see what the models show after this weekend for the first week in February

[tron777]

12Z Euro of course has rain with the next system maybe ending as a few flakes on Monday. Otherwise it keeps most everything suppressed until the night of 2/1 and GHD when some kind of frozen precip falls. Then we get cold again.

[tron777]

On the EPS freebie maps, I am seeing some light precip on Monday but the higher precip signal is def around GHD. If anyone has access to the precip type maps like we can see for free on the GEFS, please post. Thanks!

[tron777]

We are just starting to get into the NAM's range for early next week. 18Z run has a touch of snow, sleet, and rain for the area Mon morning with a better shot of sleet and snow coming into the Tri-state at the end of the run for Mon night when the model ends.

[tron777]

18Z RGEM is starting to barely come into range as well and for Mon morning it is much further north with the boundary and actually passes a weak surface low thru SW Ohio so it's mainly light rain for most folks. Then, for Mon night when the model stops, sleet moves in for us with snow for I-70 corridor.

[Bgoney]

On the EPS freebie maps, I am seeing some light precip on Monday but the higher precip signal is def around GHD. If anyone has access to the precip type maps like we can see for free on the GEFS, please post. Thanks!

All I saw was the ice probability map from the EU like the one from yesterday and it shows the best chance for ice is Wednesday pm into the day Thursday

[tron777]

Latest thoughts from the boys which certainly spells out the uncertainty with the forecast next week.

.LONG TERM /SUNDAY THROUGH THURSDAY/...
At the onset of the long term period, a weak low pressure and
cold front is impacting the Ohio Valley with southerly flow
ahead of the cold front, along with periods of light rain. Wind
gusts of 25-30 mph can also be expected ahead of front. As the
cold front moves into the area during the afternoon,
temperatures drop first across western Ohio with colder air
settling in area-wide during the evening. Sunday night into
Monday morning, deeper moisture lingers along the front, with
drizzle or light showers persisting in southern Ohio and
northern Kentucky. Undercutting cold air will need to monitored
for below freezing temperatures as some guidance suggests
freezing rain or freezing drizzle is possible.

High pressure builds over the region Monday night through
Tuesday, however, precipitation chances increase once again
Tuesday as a weak shortwave combines with a weak disturbance
moving out of the southern Plains. Precipitation chances remain
focused along the Ohio with this particular feature.

Tuesday night through Thursday, zonal steering flow aloft
prevents deeper moisture from surging northward, but this allows
colder air to filter southward. Precipitation chances remain in
the forecast, but there is still great amount of uncertainty as
to how far north the eventual precipitation will be. GFS/ECMWF
ensemble suites differ significantly in timing and placement of
the best moisture and precipitation chances. The most critical
feature to track is a closed off upper level low that eventually
moves eastward toward the Ohio Valley Wednesday (GFS) or
Thursday (ECMWF). Also, if the progression of the upper level
trough to the north is deeper, the entire area would be
precipitation free and colder. With the 12Z guidance, the GFS
and ECMWF suites are essentially split 50/50 with wet vs dry.

For temperatures, along and north of I-70, confidence is high
that values will be below normal with low temperatures in the
lower teens for several nights next week. Temperatures are most
uncertain across the far south, as precipitation and
precipitation type forecasts are currently made with lower than
desired confidence.