March 2021 Weather Discussion

[Bgoney]

Pretty good agreement on a large
Dry slot Thursday after the morning slug of rain. Due to this, I think .75"- 1.50" for the area will Play out. If the low shifts further south, 2" amounts could be had.

[tron777]

Long range for the HRRR... but the 12Z run out to Hour 48 does show the dry slot coming in just after rush hour on Thurs morning so that would potentially give us a period to weakly destabilize. The low is fairly strong in the mid 990s MB as well. Again... just looking at an isolated risk for folks near and S of the River at this time.

[tron777]

12Z NAM has 0.76" of rain for CVG. The 12Z GFS is coming in with 0.82".

[tpweather]

Good Afternoon and not a bad day outside as very little wind so the morning walk was not cold at all. Lets see how much precip the Euro comes out with for the next system. At one time I believe it had over 2 inches in the forecast. Though I believe the Euro may have the correct track and less of a chance of severe weather the amount just seems to high for a few reasons. Progressive system, storms south of us may take away some of the needed moisture. I like the call by Bgoney of .75 to 1.5 seems good though most should be on the lower side unless you get an extended period of heavy rain or a quick thundershower.

Next week I believe is the start of a very stormy period for us and could ramp up very quickly with a severe outbreak. Temps are looking to really jump up iN the south plus we have several systems in the pacific working its way towards the USA. To me this spells several severe outbreaks in the next 5 weeks and likely to continue into at least early May before summer tries to work itself in the picture. I tend to downplay what I see when models show severe weather because they imo do a terrible job. The pattern coming up screams severe outbreaks. Will they occur here and again just like a winter storm to hard to predict this far out but the setup is the best I have seen in years in terms of getting severe outbreaks. Not sure we will break any kind of records for severe storms but I believe an above normal season is likely.

[tron777]

Hey Tim... those 2" totals from past Euro runs would be correct if the low tracked further south and we'd be in the deformation zone. That is what it looked like the other day. Now that the low is expected to track closer to us if not a bit north of us, I agree on tapering down the rainfall amounts a bit. That is the reason we're seeing that dry slot for a good portion of Thursday. Whether we can see any instability or not for severe wx is still in question. Either side of an inch is a good call for rain so we're all in agreement there. We'll just have to wait and see if any destabilization can occur. Dynamics wise, we are good to go with wind shear and helicity thanks to the low being nearly on top of us.

For the long term severe prospects, I agree fully with your thoughts. April should get quite active. We are 100% on the same page there!

[cloudy72]

Stubborn clouds - only 50 here. 70s a bit to our south across central and southern Kentucky.

[tron777]

12Z Euro has toned it down... 1.15" at CVG so models are coming into agreement with a surface low track right over us.

[tron777]

Stubborn clouds - only 50 here. 70s a bit to our south across central and southern Kentucky.

53 at CVG as of 2pm. Visible shows that the sun is out just S of the Metro. Still overcast imby.

[cloudy72]

Latest SPC day 2 outlook hinting at upgrade to High risk (5 out of 5) at their 06z update tonight for LA, MS and AL for tomorrow.

Further east across northeast LA into MS and AL a more concerning
scenario appears possible. Most forecast guidance agrees that a
round of afternoon thunderstorms are expected. This activity is
expected to develop in weaker ascent, driven by heating and low
level warm advection. Strong 0-3 km shear near 30-40 kt will already
be in place with enlarged low level hodographs evident. Given weaker
forcing, this activity will have an opportunity to remain more
discrete and any cell will quickly become a supercell capable of
producing strong tornadoes. As a 40-50 kt low level jet increases
around 00-03z, intense supercells are expected to advance eastward
along with the cold front across MS and into AL overnight. This will
bring a second round of significant severe storms capable of intense
tornadoes, large hail and intense damaging winds across much of
MS/AL. If these trends are maintained, an upgrade to a High risk
could be necessary with the initial Day 1 Convective Outlook at 06z
tonight.

[tpweather]

Latest SPC day 2 outlook hinting at upgrade to High risk (5 out of 5) at their 06z update tonight for LA, MS and AL for tomorrow.

Further east across northeast LA into MS and AL a more concerning
scenario appears possible. Most forecast guidance agrees that a
round of afternoon thunderstorms are expected. This activity is
expected to develop in weaker ascent, driven by heating and low
level warm advection. Strong 0-3 km shear near 30-40 kt will already
be in place with enlarged low level hodographs evident. Given weaker
forcing, this activity will have an opportunity to remain more
discrete and any cell will quickly become a supercell capable of
producing strong tornadoes. As a 40-50 kt low level jet increases
around 00-03z, intense supercells are expected to advance eastward
along with the cold front across MS and into AL overnight. This will
bring a second round of significant severe storms capable of intense
tornadoes, large hail and intense damaging winds across much of
MS/AL. If these trends are maintained, an upgrade to a High risk
could be necessary with the initial Day 1 Convective Outlook at 06z
tonight.

Mike I agree with this and believe this is going to be the norm this spring and of course that will include us locally. So many systems in the pacific and that can spell trouble for the USA in the spring.

[tron777]

Can't blame the SPC for doing that. If the CAP erodes as expected, the radar will be lighting up with super cells down here tomorrow afternoon and evening. Some folks will see the storms, the further east one goes, at night which is always more dangerous.

[tron777]

A 998 MB low currently exists over Eastern New Mexico. S of the warm front in the deep south, dew points are already pretty juicy in the 60s. All you need is the lift via the cold front and Boom!

[tpweather]

Can't blame the SPC for doing that. If the CAP erodes as expected, the radar will be lighting up with super cells down here tomorrow afternoon and evening. Some folks will see the storms, the further east one goes, at night which is always more dangerous.

Agree Les and how far north will those storms go overnight into Thursday morning. Lots of moving parts

[tron777]

Can't blame the SPC for doing that. If the CAP erodes as expected, the radar will be lighting up with super cells down here tomorrow afternoon and evening. Some folks will see the storms, the further east one goes, at night which is always more dangerous.

Agree Les and how far north will those storms go overnight into Thursday morning. Lots of moving parts

Exactly Tim... that and the low track will determine our fate for anything severe on Thursday.

[cloudy72]

53 has been my high thus far and current temp. Still overcast here

[tron777]

I got up to 57. 60s just to my south by like 10 miles lol

[Bgoney]

Still like .75"-1.50" for the AV. Not impressed with severe potential. DPs being a problem here. With Severe weather to our south and with the low moving due east, should keep better return flow and severe storms to our south. Thunder will be heard and heavy downpours especially in the early morning Thursday when best energy moves through and again early evening for our SE county's

[tron777]

The boys had this to say for the next couple of days. Looks like they are thinking isolated severe across the S counties but that's it.

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Dry weather will continue through much of Wednesday as high
pressure slowly recedes from the Great Lakes. Conditions will
begin to change Wednesday afternoon as low pressures advances
from the southwest. Clouds will thicken in isentropic lift ahead
of a warm front, and rain may arrive from the southwest by
evening. Moderate rain will then overspread the FA by around
midnight, and thunderstorms will be embedded in an environment
containing elevated instability and ample shear aloft
surrounding the boundary. Isolated severe storms will be possible,
with a lack of surface based CAPE being a limiting factor. PWAT
close to 1.3 inches will allow rainfall up to an inch in some
locations.

Highs in the 60s are forecast for Wednesday, with a modest drop
to the 40s and 50s expected Wednesday night.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Upper low over the Mid MS Valley to track east through the Tennessee
Valley Thursday afternoon/Thursday night. Associated surface low to
track across northern Kentucky and into West Virginia. Warm front to
pivot north ahead of this low to near the Ohio River. Best coverage
of rain will take place across the northern counties where best 8H
convergence will take place. In dry slot across the south -- expect
CAPE of 1000-1500 J/KG to develop across the far south. Wind flow
decreases with LLJ off to the east. Although the wind flow decreases
with cooling aloft and with instby that develops there will be a
conditional threat for severe weather across the far south Thursday
afternoon into early evening ahead of the surface wave. The main
threats will be hail and wind. Will continue to mention this threat
in the HWO product.

As the system translates east precipitation will come to an end late
Thursday night into Friday morning. As the low moves off to the
east, a tight pressure gradient will develop between the low and
high pressure building into the Great Lakes. Expect sustained winds
of 25 mph with gusts up to 40 mph Thursday night into Friday.

[MVWxObserver]

I didn't have my gauge out for this most recent system because of the temp fluctuations here north of I-70 and having started out as some icy mix late yesterday afternoon. Got jolted awake between 3 and 3:30 this AM by some thunder and a downpour.

Will have my gauge out for the late Wed night through Thurs evening one.

Also will be keeping tabs on Tues 3/23 as a tree surgeon guy will be coming to grind down a stump in the backyard. Currently there's a 30% to 40% chance of scattered showers for that day.

Currently 45 here in G'ville.

[MVWxObserver]

Prayers and thoughts with those in the severe set-up zones today through Thurs.

[tron777]

Looks like the action will be starting tonight Across TX / OK as the surface low begins to make its move. No watch boxes out yet but a couple of MD's have been issued where at least 1 watch is likely to be issued soon in that area. The big show will be tomorrow afternoon and evening to our south.

[cloudy72]

Actually peaked at 54 today.

[Trevor]

18z NAM updraft helicity is a bit concerning.

[Trevor]

Need to watch this on the overnight and morning model runs for tomorrow night. With the low so close by, it won’t take much for a cell or two to get out of hand (tornado producers).

[Trevor]

Until more data is available, I agree with the SPC placement for now (re: day three outlook from earlier today). They may push the slight further north on their next update. We’ll see. But with the low modeled to pass right over us (or just south), we have got to watch it. Too close for comfort. Obviously the main outbreak will be south. But given the proximity of the low track, there may very well be some late night severe thunderstorm or maybe a tornado warning or two in the ILN coverage area tomorrow night/early Thu morning.