snowlover2

2 minutes ago, pen_artist said:

Is anyone able to get an image of this outlook on a county level for N IL?

December 22-23, 2004. Couldn't have been more perfect at least for my part of Ohio.

1 minute ago, Hoosier said:

There's a hatched 15% wind area on the day 2 outlook, owing to the uncertainty/varying scenarios but with higher end potential.

 

Forecast Discussion

SPC AC 120558 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Sun Jun 12 2022 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS...AND THE MIDWEST/GREAT LAKES INTO THE OHIO VALLEY... ...SUMMARY... Scattered severe thunderstorms should develop Monday across parts of the northern Plains, and from portions of the Midwest into the Great Lakes and Ohio Valley. Large hail, damaging winds, and a few tornadoes all appear possible. Some of the winds could be significantly severe (75+ mph) across parts of the Midwest/Ohio Valley Monday afternoon. ...Synopsis... A large-scale upper trough initially over the western CONUS will move slowly eastward across the Intermountain West on Monday, eventually reaching the northern/central Rockies and adjacent High Plains by late Monday night. An upper-level ridge should persist over much of the MS Valley into the Southeast, with another upper low forecast to remain over Quebec. Enhanced west-northwesterly mid-level flow should be present over parts of the Midwest into the Great Lakes, OH Valley, and Mid-Atlantic on the northeast side of the upper ridge. At the surface, a lee cyclone should consolidate over the northern and central High Plains by Monday evening, with another low over southern Saskatchewan. Rich low-level moisture should return northward across much of the northern Plains along/east of a front extending between the two surface lows. A warm front is also expected to lift northward across parts of the Midwest into the Great Lakes and OH Valley through the day, with a very moist low-level airmass present along/south of the warm front. ...Northern Plains... Modest mid-level height falls and ascent preceding an upper trough should overspread parts of the northern Plains by Monday evening. Diurnal heating of a moist low-level airmass to the east of a front should encourage the development of moderate to strong instability by late Monday afternoon across parts of western SD and vicinity. Strong deep-layer shear of 50+ kt will easily support supercells with any convection that can develop and persist. Most guidance suggests that thunderstorms will initially develop by late Monday afternoon across far northeastern WY/southeastern MT, and quickly strengthen as they spread northeastward across western/central SD and ND Monday evening/night. The rather favorable thermodynamic and kinematic environment will support a threat for both large hail and severe winds with supercells as the dominant mode initially. Some of the hail could be very large (2+ inches) across parts of western SD and vicinity Monday afternoon/evening, as steep mid-level lapse rates and 2000-3000+ J/kg of MLCAPE will likely be present. With time, some upscale growth into a cluster may occur across ND Monday night as a cold front moves eastward. Given the large amount of buoyancy forecast, damaging winds and hail may continue to be a threat even if convection becomes slightly elevated. A few tornadoes may also occur with any supercell, mainly late Monday afternoon and early evening, across parts of western SD into ND as low-level shear increases. ...Upper Midwest into the Great Lakes and Ohio Valley... Thunderstorms may be ongoing at the start of the period Monday morning across parts of the Midwest (IA/MN and vicinity). This activity could pose an isolated severe hail/wind threat as it moves eastward Monday morning. There may be an MCV associated with this morning convection, and some guidance also shows a corresponding mid-level vorticity maximum and enhancement to the mid-level winds. Although details in convective evolution remain unclear Monday afternoon, there is increasing concern that redevelopment of intense thunderstorms could occur with the MCV across parts of southern WI/northern IL into southern Lower MI, IN, and OH. Strong to extreme instability (MLCAPE 3000-5500+ J/kg) will likely develop along/south of a warm front across these areas. Low to mid 70s surface dewpoints, strong diurnal heating, and steep mid-level lapse rates will all contribute to this large reservoir of buoyancy. 35-45+ kt of deep-layer shear should also be present with the enhanced mid-level west-northwesterly flow on the northeastern periphery of the upper ridge. This volatile environment will support significant severe potential with any thunderstorms that can form along/south of the warm front. At this point, there is still a substantial amount of uncertainty with where/if thunderstorms redevelop by Monday afternoon. Both global and convection-allowing model guidance show large variability in possible solutions, which range from little to no surface-based convective redevelopment, to an intense, bowing MCS sweeping southeastward in a narrow corridor across parts of the Midwest into the OH Valley through Monday evening. Given these uncertainties, have opted to include greater (15%) severe wind probabilities and add a significant severe wind area where confidence in an MCS occurring is somewhat better. Isolated large hail may occur with any embedded supercell. A few tornadoes also appear possible, as low-level shear will be maximized along and just south of the warm front. If confidence in the MCS scenario occurring increases, then even greater severe probabilities would likely be needed owing to the very favorable thermodynamic environment. The eastern/southern extent of the severe threat is also uncertain, so have expanded the Marginal Risk across the OH Valley into the central Appalachians to account for a broad range of possible tracks to the MCS before it eventually weakens Monday night. ..Gleason.. 06/12/2022

Beat me to it. That's some pretty strong wording.

18-8-3

New day 2 mentions EF3+ tornado possible.

Quote

 Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0101 AM CDT Sun May 01 2022

   Valid 021200Z - 031200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   OKLAHOMA AND SOUTHERN KANSAS...

   ...SUMMARY...
   A severe threat is expected to develop on Monday over the southern
   and central Plains eastward into the Ozarks. Large hail, wind damage
   and tornadoes will be possible Monday afternoon and evening. A
   marginal severe threat will also be possible across parts of
   west-central Texas and in the western Tennessee Valley.

   ...Southern and Central Plains...
   An upper-level trough will move eastward across the southern and
   central High Plains on Monday, as a 45 to 60 knot mid-level jet
   translates eastward through the base of the trough. At the surface,
   a low will move southeastward into northwest Oklahoma as a cold
   front advances southeastward across western Kansas and into western
   Oklahoma. By afternoon, a dryline will setup from a frontal triple
   point in western Oklahoma extending south-southwestward into
   northwest and west-central Texas. A warm front will advance
   northward across eastern Kansas and central Missouri. Surface
   dewpoints across the moist sector will be in the mid 60s F, where
   moderate instability is expected by afternoon. Convection is
   forecast to initiate ahead of the cold front from south-central
   Kansas into north-central Oklahoma during the late afternoon. Rapid
   thunderstorm intensification should occur with several clusters of
   strong to severe thunderstorms moving eastward from central and
   northern Oklahoma into eastern Kansas during the early evening.
   Isolated thunderstorms are expected further south-southwest along
   the dryline into parts of northwest and west-central Texas.

   The environment across the southern and central Plains may become
   very favorable for severe storms, depending upon early day activity
   shifting eastward away from the region. NAM forecast soundings from
   Wichita southward to Oklahoma City at 00Z/Tuesday are impressive
   loaded gun soundings. MLCAPE is forecast to be in the 2000 to 3000
   J/kg range, with 0-6 km shear from 50 to 60 knot. This is combined
   with 700 to 500 mb lapse rates near 8.0 C/km, and 0-3 km storm
   relative helicities of 450 to 500 m2/s2. This will be a high-end
   parameter space very favorable for supercells with large hail, wind
   damage and tornadoes. Hailstones of greater than 2 inches in
   diameter will be possible with the more intense supercell updrafts.
   As low-level shear ramps up during the late afternoon and early
   evening, tornadoes will be possible with the more intense
   supercells. Model forecasts show a strong low-level jet response
   across northeast Oklahoma. Supercells that develop to the west and
   northwest of the low-level jet should be associated with a threat
   for strong tornadoes, and an EF3+ tornado may occur. In addition,
   wind damage will be possible with supercells, and with organized
   short bowing line segments.

   A severe threat should develop south-southwestward into northwest
   Texas and west-central Texas to the east of the dryline, but
   convective coverage will be more isolated there. Large hail and wind
   damage would be possible with supercells that form in the late
   afternoon and early evening.

49 minutes ago, Indystorm said:

Seems to be a bit of confusion at NWS Chicago.   "Radar confirmed" tornado warning issued for the Oak Brook area and shortly thereafter cancelled.  Was there an actual touchdown?  Tag said "observed."

It was radar confirmed which means there must have been debris showing up and it could have been brief leading to cancelation.

Quote

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Chicago/Romeoville
449 PM CDT Sat Apr 30 2022

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  East central DuPage County in northeastern Illinois...
  Central Cook County in northeastern Illinois...

* Until 515 PM CDT.

* At 449 PM CDT, a tornado producing storm was located over Oak
  Brook, moving northeast at 25 mph.

  HAZARD...Damaging tornado.

  SOURCE...Radar confirmed tornado.

  IMPACT...Flying debris will be dangerous to those caught without
           shelter. Mobile homes will be damaged or destroyed.
           Damage to roofs, windows, and vehicles will occur.  Tree
           damage is likely.

* This tornadic storm will be near...
  Westchester, Northlake and Hillside around 500 PM CDT.
  Elmhurst, Maywood, Bellwood and Broadview around 505 PM CDT.

Other locations in the path of this tornadic thunderstorm include
Melrose Park, Forest Park and River Forest.

Including the following interstates...
 I-88 between mile markers 137 and 140.
 I-290 between mile markers 13 and 20.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This Tornado Warning replaces the Severe Thunderstorm Warning issued
for the same area.

25 minutes ago, pondo1000 said:

Maybe a couple clippers in our future?

Could be something Wed night/Thursday that's been shifting north some and currently showing some snow along the Ohio River area.

Got a little more than 2" here in Dayton. That west outer band was a nice surprise.

Got around an inch here. This outer band is a nice surprise.

3k NAM still snowing in C/E Ohio. Northern energy snow showers in IN.

0z NAM continues the trend of the 18z Euro.

24 minutes ago, buckeye said:

18z euro    nice shift west

Quote

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Deep, but unphased, troughing will be positioned near the NE coast
of the CONUS for the start of the period with NW flow aloft over the
OH Vly transitioning to more quasi-zonal flow through the day on
Friday. The final day of the workweek will have the region squeezed
between the system exiting the eastern seaboard and the next one in
line, which will be progressing quickly from the Upper Midwest to
south-central plains Friday into Friday night.

By this time, attention will be squarely focused on the second of
the aforementioned systems -- the one tracking almost N-S through
the central plains on Friday. Longer-range guidance remains in
relatively good agreement showing this midlevel S/W transitioning to
a closed low by Saturday morning in the vicinity of KS/OK. This
feature will be responsible for a rather impressive band of wintry
pcpn on the NE periphery of the track, which will likely position
itself from MN to MO during this time period, with the ILN FA & OH
Vly staying pretty confidently to the east of any pcpn through the
daytime on Saturday. Cannot completely rule out a few flurries,
perhaps, near/south of the OH Rvr by later Saturday evening, but the
guidance trend in taking this feature further west has left us with
pretty high confidence in a dry Saturday here locally as highs
ranging from the mid 20s to lower 30s (N-S, respectively) locally.

This is a complex winter system that will likely evolve from the
ArkLaTex region E/NE through the TN Vly and eventually into the NE
CONUS from Saturday night through Sunday. While it seemed like
previous data runs had all but written off any notable impacts
locally, the latest trends, both deterministically and from an
ensemble perspective, suggest this perhaps may not entirely be the
case. GEFS/GEPS/EPS ensemble means have all taken considerable jumps
further to the NW with the boomerang re-curvature of the system from
the northern Gulf to near/west of the spine of the Appalachians
before eventually the primary energy transfers closer to the coast,
with the inland low becoming somewhat orphaned by later Sunday.

There are several things to break down regarding potential
accumulating wintry pcpn locally late Saturday night through Sunday.
The first, and perhaps most important, aspect will be the timing of
the transfer of energy from the initial inland low to the coastal
low sometime between Saturday night and Sunday night. The prevailing
guidance would suggest occlusion of the initial sfc low in MS/TN
Saturday night with the development of a secondary low toward SC by
Sunday morning. The occlusion of the low would signal a gradual loss
of baroclinicity associated with the inland low, which guidance
suggests may track from TN NE through the ern OH Vly during the day
on Sunday. The occlusion of the LL system, prompting the loss of
baroclinicity, due in part of the lack of arctic air building in
quickly from the NW, suggests a gradual decrease in lift/LL
convergence associated with any banded pcpn. In fact, there would
likely be frontolysis underway with this system as it tracks closer
to the ILN FA Sunday, leading to uncertainties in just how
widespread and/or intense any wintry pcpn may be. There is no sharp
temp gradient or strong frontogenetic axis to work with here,
especially as the coastal low becomes the primary one on Sunday with
explosive cyclogenesis occurring in the mid-Atlantic region.

With all of this being said, it cannot be ignored the obvious and
sudden shift to the NW with the inland low tracking to the NE
near/west of the Appalachians -- a climatologically-favorable track
for accumulating snow in the OH Vly. Although there remains some
positional variability that will ultimately play a significant role
in the evolution of the system and potential impacts locally, this
trend has shown itself almost unanimously across the GEFS/GEPS/EPS
ensemble quites. Most guidance would suggest that the column may get
/just/ warm enough to promote a mix of rain/snow during the
afternoon in N KY and south-central OH, with the predominant p-type
remaining snow elsewhere with a subzero (C) profile and ample
saturation in the DGZ coinciding/overlapping with some vertical
motion with the mid/upper level low tracking through the region.
Ensemble mean probabilities continue to suggest increasing potential
for light accumulations of snowfall (1"/3") or less near/SE of the I-
71 corridor on Sunday. These ensemble means do assume a 10:1 SLR,
which would likely just a bit higher than we would be dealing with
(we may be closer to 8:1 or 9:1, depending on location).
Nevertheless, the trends with the overall closed low tracking
further to the N/W, with implications on the track of the inland
(filling) low, have raised PoPs above the blended guidance for
Saturday night through Sunday and will introduce a broad-brushed HWO
mention for now. Certainly we are still several model runs away from
being able to hone-in on whether this system will be more of a
nuisance, or perhaps a bit more significant, so we will continue to
adjust the forecast as trends and patterns dictate.

Another "kicker" S/W will pivot SE from the Upper Midwest to the OH
Vly immediately behind the "main" system for Sunday night into
Monday morning. This system may have enough additional lift to
generate some snow showers during the day on Monday as temps remain
several degrees below seasonal norms. Have not added slight chance
PoPs yet for this time period as confidence remains low at this time
in the exact track and strength of this feature. But some lake-
effect/enhanced snow showers N of the immediate local area seem like
a good bet at this juncture for the start of the workweek.

From ILN

12z GGEM finally loading and it looks very similar to the GFS.

12z Ukie took a nice jump NW. Has snowfall east of I-71 where the 0z was in VA/Carolinas.

0z Ukie not buying any of this yet.

18z GFS is not terrible.

Euro joins in with the GFS trying to pull this sucker NW on the curve around.

12z GGEM also appears to have comeback NW some on the swing around.

Very lightly snowing here in Dayton.

0z GFS finally has a storm giving SE parts of Ohio a couple inches.