March 2023 Weather Discussion

[tron777]

From the boys:

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Mid level energy will spread east into the Tennessee and Ohio
Valleys tonight. An associated surface low will track east
across the Tennessee Valley with an inverted trough extending
northward and traversing the Ohio Valley later tonight into
Sunday. There remains some strength and timing issues amongst
the models with this system, but the overall trend has been a
little faster along with a bit of a weakening trend as the
better forcing moves into our area.

Deeper moisture will increase ahead of the system with pcpn
spreading into our southwest toward midnight and then
overspreading the rest of our area later tonight into Sunday
morning. Thermal profiles support mainly snow at the onset and
through much of Sunday morning along and north of the Ohio
River, with more of a rain/snow mix to the south. Will continue
to undercut guidance for temps on Sunday with highs mostly in
the mid to upper 30s, but even with that, we should see a
transition over to more rain from the south through the day on
Sunday.

Snowfall amounts will be tricky given the relatively warm
ground and time of year. Would expect the better chance for more
accumulations to be across our Indiana counties where forcing
will be a little better and pcpn will move in the earliest and
thus be falling the longest during the nighttime period. In
these areas one to locally two inches seem possible, especially
on grassy and elevated surfaces. Further east, the combination
of less forcing and more of the snow falling during the daytime
period, think accumulations will generally be an inch or less

[Trevor]

Good update from them. The overnight models sure did show a weakening trend as the system arrives. In general the forecast remains unchanged, but I like their idea of the best chance for 1-2” being in Indiana.

[Trevor]

12z HRRR shows the weakening trend as the precip shield enters the area. As I previously stated, the forecast remains largely unchanged. However, best chance for some 2” amounts would be over our SE Indiana counties. Up to an inch for the rest of us with localized higher amounts over an inch. I doubt this will require a NWS headline given the minimal road impacts.

[tron777]

12Z NAM is similar... 0.11" for QPF at CVG to work with.

[tron777]

9Z SREF plume shows a range of 0 to 2.6" for a mean of 0.70" at CVG.

At CMH, a mean of 0.86" because of a 4" weenie member.
At DAY, a mean of 1" because of a 4" and 5" weenie members.

[tron777]

Last early day for model runs since the time changes tonight. We spring forward. I hate losing that hour of sleep. Luckily for you, there are no forum changes that need to be done. It's automatic now. Should be using your system time zone anyway I believe. Probably will be heading to my brother's in the morning to make some breakfast sausage since the weather is cold.

[tron777]

0.14" QPF for tonight at CVG from the GFS.

[tpweather]

Good Morning Les and even some of the qpf totals will go into melting. I would be very surprised if any location gets more than 1 inch out of this system. Though the timing is good the surface temps are warmer than normal for this time of year. My major concern is early next week and the chances of a hard freeze.

Looking further out the models seem to be moving things quickly and I am not sold on that if the NAO stays rather negative. If it heads back to positive or even neutral then I can see the faster solution but at this point I expect a decent system late in the week but whether we can get any snow out of it is up in the air.

[tron777]

I still don't know either Tim if it'll be a glorified frontal passage or a secondary low that would bring in more rain / snow. I'll keep both options open for now.

[tron777]

12Z Euro up to 0.14" now for tonight / tomorrow morning at CVG.

[Trevor]

In my post earlier I said I found it unlikely that ILN would issue any headlines, but alas they did for a few counties in the immediate metro area. Text calls for up to 2" of accumulation.

[tpweather]

In my post earlier I said I found it unlikely that ILN would issue any headlines, but alas they did for a few counties in the immediate metro area. Text calls for up to 2" of accumulation.

Trevor I was surprised of the advisory. I guess since we have not had much in the way of snow this season that the snow may catch some folks off guard. Still believe its going to hard to accumulate on roadways but the timing in the middle of the night through mid-morning does help.

[Trevor]

18z HRRR doesn't weaken the precip shield as quickly as previous runs. 0.15-0.22" across the area as mostly snow. Having said that, temperatures are so marginal --> 31-34 during the snow. Road conditions should remain fine overall save for isolated brief, quickly-melting coatings on roads under a heavier burst.

Personally, I think the advisory is a bit of overkill.

[Trevor]

In my post earlier I said I found it unlikely that ILN would issue any headlines, but alas they did for a few counties in the immediate metro area. Text calls for up to 2" of accumulation.

Trevor I was surprised of the advisory. I guess since we have not had much in the way of snow this season that the snow may catch some folks off guard. Still believe its going to hard to accumulate on roadways but the timing in the middle of the night through mid-morning does help.

I agree and touched on that in my last post as well. Any help to add to the seasonal totals is much appreciated by the snow weenies on here! lol

[tron777]

I'll be up early watching it snow and heading to my brothers around 8-9am in the morning. Should be interesting.

[tron777]

From the boys:

The mid/high level clouds are increasing ahead of a system which
will impact the local area tonight into early Sunday morning.
There are several complexities with this setup to consider, most
notably of which will be the degree to which the H8-H7
WAA/isentropic lift and moisture transport will be able to
overcome the antecedent dry profile entrenched across much of
the region. The rate at which saturation of the profile can be
attained will ultimately determine how quickly (and how much)
snow will fall as the isentropic lift quickly pivots E into the
area past midnight. If the lift and initial pcpn rates are
substantial enough, sufficient cooling and moistening of the
column could very well yield a somewhat narrow axis/corridor of
2+ inches of snow extending from parts of SE IN through extreme
SW OH and nrn KY. The time of day (or night, in this case)
bears favorably for more efficient accumulation prior to sun-up,
with most of the 1-2" of snow forecast within this corridor
expected to accumulate prior to daybreak. This being said, there
should be a fairly sharp gradient on the nrn/ern side of this
band, owing to replenishment of dry air due to easterly flow in
the LLs, with steadier snow rates having a much more difficult
time evolving for locales into the Miami Valley/WC OH and
central OH. Latest short-term and synoptic-scale ensemble suites
suggest the most favorable area of 2" (or slightly more) to be
approximately laid out where the Winter Weather Advisory has
been issued. The trend for this focused axis of slightly heavier
pcpn rates has been to the south with recent guidance runs. And
although it is a weekend (suggesting less AM commute traffic)
and /very/ marginal road temp traces through the nighttime
(road temps staying mainly in the mid/upper 30s), the snow
rates within this corridor may briefly overcome these opposing
conditions to yield some snow-covered roads/bridges prior to
daybreak. And with this fcst adjustment, feel confident with
trending snow amounts down for parts of central OH as the dry
air entrainment in these areas should be more pronounced, thus
leading to delayed snow reaching the ground, lighter rates, and
lower accumulation efficiencies.

Temps for tonight should cool fairly rapidly with the onset of
pcpn as wet-bulbing takes over and sfc temps dip to around
freezing (or perhaps a degree either side) for areas in which
snow is falling. So we should see air temps dip by at least
several degrees within an hour or two as the pcpn moves in,
trending from the mid/upper 30s to the lower 30s from SE/EC IN
through nrn KY.

[tpweather]

I'll be up early watching it snow and heading to my brothers around 8-9am in the morning. Should be interesting.

Hey Les and I am usually up by 6am at the latest. Yes I believe the ground is warm and the roads and sidewalks should be fine. What you may see is one small band of heavier snow which I saw out west earlier this morning and if you can be under that band for a few hours you can hit that 1-2 inches on the grassy surfaces. The problem of course is where does that heavier band set up and we may not that until well after mid-night. The band will be narrow so it may be 20 miles wide at best.

[tron777]

...WINTER WEATHER ADVISORY IN EFFECT FROM 11 PM EST THIS EVENING
TO NOON EDT SUNDAY...

* WHAT...Snow expected. Total snow accumulations of up to two
inches, especially on grassy and elevated surfaces.

* WHERE...Portions of Southeast Indiana, Northern Kentucky and
Southwest Ohio.

* WHEN...From 11 PM EST this evening to noon EDT Sunday.

* IMPACTS...Plan on slippery road conditions.

[tron777]

I'll be up early watching it snow and heading to my brothers around 8-9am in the morning. Should be interesting.

Hey Les and I am usually up by 6am at the latest. Yes I believe the ground is warm and the roads and sidewalks should be fine. What you may see is one small band of heavier snow which I saw out west earlier this morning and if you can be under that band for a few hours you can hit that 1-2 inches on the grassy surfaces. The problem of course is where does that heavier band set up and we may not that until well after mid-night. The band will be narrow so it may be 20 miles wide at best.

Our first event Tim in what 30 some days? Last event was in late January. We are well overdue. The pattern is already producing. We said days ago after 3/10 and lookey here! I'll take a one day late call every time. Although, an advisory event does surprise me. I wasn't expecting this much QPF. Let's see some of the early guidance this evening says. Last early model runs lol

[tron777]

This system is not weakening yet. MD issued for a possible t-storm watch tonight down near the triple point in the Ark-La-Tex area.

https://www.spc.noaa.gov/products/md/md0273.html

[tron777]

We have a non phased system so we can't go crazy with snow amounts or QPF, but a 1000 MB low down in Texas is our moisture source with a 1006 MB low over ND. Lows will stay separate but while they interact for a few hours tonight, we have to make hay before the precip dries up.


You've gotta like the frontogenic forcing to our west.

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Per radar, most of this will fall at night. With the time change it won't get light until around 8am or something.

[tron777]

18Z Euro coming in with 0.13" QPF at CVG.

[MVWxObserver]

Less than a half inch expected here in Greenville for late tonight through Sun morning.

Currently 36 here and progged for around 29 in the morning.

Probably has been mentioned already but don't forget to Spring Forward tonight!

Wish Congress would enact DST year-round imo since 8 months already have that anyway.

The springing forward and falling back gets old after a while.

[Trevor]

Around an inch here in Lebanon on my car. Pavement is wet as we expected.

[Bgoney]

Zilch here, temp above freezing most of night