June 11-24, 2022 | Northwest Flow Severe Weather/Ring of Fire

[snowlover2]

ILN discusses the situation both today and tomorrow but also mention down the road on Thursday that there could be pop up storms with downburst potential.

Quote

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
653 AM EDT Sun Jun 12 2022

.SYNOPSIS...
Weak disturbances moving through an increasingly warm and moist
atmosphere will result in periodic chances of showers and
thunderstorms through Monday night. Heat will build quickly and
Tuesday and Wednesday will see the heat index rise above 100.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Convectively-enhanced short wave in the upper Mississippi
Valley early this morning will dive southeast into the area. In
addition, a weak front will be sliding east southeast. This will
lead to more showers and thunderstorms moving across the
forecast area during the day. CAPE is forecast to reach
1000-1500 J/kg and shear will be increasing. So some strong to
severe storms will be possible. Wind is the primary threat.

Although there will be some sun, expect enough cloud cover and
precipitation coverage during peak heating to keep highs in the
lower 80s in most areas.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
While there is uncertainty in timing convection, it appears that
the initial daytime activity may be moving out of the forecast
area at the beginning of the period. But high resolution
guidance has been indicating that after a brief lull, additional
showers and storms may develop within the same corridor during
the evening and continue into the overnight before finally
coming to an end.

It appears that the effective surface front will sink through
much of the forecast area tonight. This boundary will lift back
north across the area on Monday. Cannot completely rule out a
few storms during the day although they would likely be elevated
given warm lower layers. There is some potential for a
convective system to move into northwest counties late in the
day. If that can occur, then that would be surface-based and
tap into very strong instability. However, convective evolution
for Monday from the upper Midwest into the Great Lakes and Ohio
Valley is highly uncertain. Damaging winds would be the primary
threat, but this is highly conditional on whether and where
storms occur.

Temperatures will be above normal with lows in the upper 60s to
lower 70s and highs in the mid to upper 80s. Expect the heat
index to approach 100 in parts of the Tri-State, mainly south of
Cincinnati.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Upper level ridging will be building across the Ohio Valley Monday
night while a warm front continues lifting into Michigan and
Ontario. This synoptic setup is expected to be favorable for
potential MCS development and maintenance along and south of the
front. Any MCS formation across lower Michigan on Monday afternoon
would need to be monitored into Monday night in case the MCS starts
to move right (southward) into the higher instability airmass across
the Ohio Valley. Strong straight line winds are the main threat
although hail and tornado potential can`t be ruled out especially
along and north of I-70. Moving forward, it is important to note the
potential occurrence and position of an MCS Monday night is highly
uncertain at this time especially on the fringe of mesoscale
guidance. Forecast lows are in the middle to upper 70s.

Anomalously strong upper level ridging and near record high
temperatures (middle 90s) dominate the forecast headlines for
Tuesday and Wednesday (possibly Thursday as well). The potential for
the heat index exceeding 100 still appears fairly likely since
dewpoints will be downright tropical and in the lower to middle 70s.
Warm overnight lows in the middle to upper 70s, combined with the
muggy dewpoints, will not provide much relief. The best chance for
brief breaks in the heat will come in the form of popup diurnal
convection on Wednesday and Thursday. Any storms that do form could
pose a downburst risk in the high DCAPE environment.

The next front is expected to cross the area in the Thursday
night/Friday timeframe bringing the chance for showers and storms.
Temperatures and dewpoints drop behind the front.

 

 

[junior]

I had a weird dream last night or a day or so ago where there were some really strong damaging winds here. I only remember looking out the window and seeing a whiteout with debris flying around. 

[snowlover2]

2 minutes ago, junior said:

I had a weird dream last night or a day or so ago where there were some really strong damaging winds here. I only remember looking out the window and seeing a whiteout with debris flying around. 

I unfortunetly lived that June 23, 2014 from that microburst that moved south to north across eastern Montgomery county. Didn't see debris flying around but it was a whiteout. 

[FortySixAnd32]

1 hour ago, snowlover2 said:

ILN discusses the situation both today and tomorrow but also mention down the road on Thursday that there could be pop up storms with downburst potential.

 

Sounds like I need to prepare now. And my son will be out in the middle of nowhere for youth church camp with minimal shelter. Ugh!!!

[snowlover2]

2" hail report in west IN.

Quote

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1117 AM EDT SUN JUN 12 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1035 AM     HAIL             CAYUGA                  39.95N 87.46W
06/12/2022  E2.00 INCH       VERMILLION         IN   PUBLIC

 

 

[snowlover2]

Quote

 Mesoscale Discussion 1128
   NWS Storm Prediction Center Norman OK
   1015 AM CDT Sun Jun 12 2022

   Areas affected...Parts of east central Missouri and central/southern
   Illinois and Indiana

   Concerning...Severe potential...Watch unlikely 

   Valid 121515Z - 121715Z

   Probability of Watch Issuance...20 percent

   SUMMARY...It currently appears most probable that ongoing strong
   thunderstorm development will tend to wane through midday.  However,
   until it does, occasional severe hail and locally strong surface
   gusts will remain possible.

   DISCUSSION...Ongoing storms slowly approaching the Interstate 70
   corridor might be aided by forcing associated with a subtle short
   wave impulse progressing around the northeastern of prominent
   mid-level ridging centered over the southern Great Plains.  This is
   also near and east of the plume of much warmer and more strongly
   capping elevated mixed-layer air spreading east of the Great Plains.
    
   As the weak impulse progresses into the lower Ohio through this
   afternoon, and much more prominent upstream mid-level troughing
   progresses inland of the Pacific coast, models suggest that the
   warmer and more strongly capping elevated mixed-layer air will
   continue to spread east of the mid/lower Mississippi Valley
   vicinity.  Based on forecast soundings, among other model output, it
   appears that this may occur faster than any eastward advection of
   the higher boundary-layer moisture content (supportive of the large
   CAPE), which may remain focused near/west of the Mississippi Valley,
   closer to deeper surface troughing across the Great Plains.

   Given expected trends for increasing mid-level inhibition and
   weakening supporting forcing for ascent, it remains unclear how much
   longer stronger thunderstorm development supportive of severe hail
   and strong surface gusts will be maintained.

   ..Kerr/Guyer.. 06/12/2022

 

 

[ClicheVortex2014]

Not Kansas, not Nebraska, not Iowa, but southwest Michigan 

[StormfanaticInd]

7 minutes ago, ClicheVortex2014 said:

Not Kansas, not Nebraska, not Iowa, but southwest Michigan 

Those are just crazy parameters 

[StormfanaticInd]

Spc really taking its time with the new outlook 

[snowlover2]

Enhanced added back in the northern plains.

Quote

DAY 1 CONVECTIVE OUTLOOK    
NWS STORM PREDICTION CENTER NORMAN OK  
1201 PM CDT SUN JUN 12 2022  
  
VALID 121630Z - 131200Z  
  
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE  
NORTH-CENTRAL HIGH PLAINS...  
  
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE  
MIDWEST/LOWER OHIO VALLEY AND VIRGINIA/NORTH CAROLINA...  
   
..SUMMARY  
  
SCATTERED SEVERE THUNDERSTORMS ARE EXPECTED ACROSS THE NORTHERN AND  
CENTRAL HIGH PLAINS LATE THIS AFTERNOON INTO TONIGHT, WITH LARGE  
HAIL AND DAMAGING WINDS THE MAIN THREATS. ISOLATED SEVERE STORMS MAY  
ALSO BE NOTED ACROSS THE LOWER OHIO VALLEY AND PARTS OF THE SOUTHERN  
MIDDLE ATLANTIC.  
   
..NORTHERN/CENTRAL PLAINS TO UPPER MIDWEST  
  
REGIONAL UPPER-AIR ANALYSIS REFLECTS AN AXIS OF MODERATE LOW-LEVEL  
MOISTURE EXTENDING WEST/NORTHWESTWARD ACROSS THE NORTH-CENTRAL HIGH  
PLAINS THIS MORNING. THIS COINCIDES WITH A BELT OF STRONG MID-HIGH  
WINDS THAT PRECEDE AN AMPLIFYING TROUGH OVER THE PACIFIC NORTHWEST,  
WITH THE AFOREMENTIONED WINDS EXTENDING OVER THE NORTHERN ROCKIES  
INTO THE DAKOTAS/MINNESOTA.   
  
INFLUENCED BY INCREASING LARGER-SCALE FORCING FOR ASCENT AND  
OROGRAPHIC LIFT IN VICINITY OF MOUNTAINS/HIGHER TERRAIN, INCREASING  
THUNDERSTORM DEVELOPMENT IS LIKELY BY MID-AFTERNOON ACROSS NORTHERN  
WYOMING/SOUTHERN MONTANA, AND A BIT LATER TOWARD THE BLACK HILLS  
VICINITY AND SOUTHWARD ALONG THE LEE TROUGH/BOUNDARY INTO WESTERN  
NEBRASKA/NORTHEAST COLORADO. INITIAL SUPERCELLS CAPABLE OF LARGE  
HAIL CAN BE EXPECTED, ALONG WITH SOME TORNADO RISK AND HIGHER  
PROBABILITY OF VERY LARGE HAIL ACROSS NORTHEAST WYOMING/FAR  
SOUTHEAST MONTANA INTO WESTERN SOUTH DAKOTA.   
  
CONFIDENCE HAS INCREASED THAT A HIGHER PROBABILITY CORRIDOR OF  
SEVERE STORMS INCLUDING UPSCALE GROWTH INTO ONE OR MORE MCSS SHOULD  
EVOLVE THIS EVENING ACROSS WESTERN/CENTRAL SOUTH DAKOTA AS WELL AS  
WESTERN NEBRASKA. AN ENHANCED RISK HAS BEEN ADDED TO THESE AREAS.  
   
..MISSOURI/KENTUCKY AND SOUTHERN ILLINOIS/INDIANA  
  
COMPLEX SHORT-TERM SCENARIO ACROSS THE REGION WITH MULTIPLE RESIDUAL  
INFLUENCES (MCV ETC.) FROM LAST NIGHT'S MIDDLE MISSOURI VALLEY MCS.  
A CONSEQUENTIAL RESERVOIR OF MOISTURE EXISTS ACROSS THE REGION PER  
12Z UPPER-AIR 850 MB ANALYSIS, EXTENDING FROM NORTHERN/EASTERN  
KANSAS INTO MISSOURI AND SOUTHERN PORTIONS OF ILLINOIS/INDIANA INTO  
NORTHERN KENTUCKY. THIS WILL CONTRIBUTE TO A VERY UNSTABLE AIR MASS  
WITH UPWARDS OF 4000-6000 J/KG MLCAPE. HOWEVER, A MAJOR COMPLICATING  
FACTOR, IN TERMS OF UNCERTAINTY, IS EXPECTATIONS FOR STEADY  
MID-LEVEL WARMING VIA THE EASTWARD-ADVECTING ELEVATED MIXED LATER.  
12Z TOPEKA, KS OBSERVED SOUNDING FEATURED A 15.2 C 700 MB  
TEMPERATURE, WHILE SPRINGFIELD, MO WAS 13.6 C. SHORT-TERM MODEL  
GUIDANCE VARIES CONSIDERABLE IN THIS MODEST FORCING/PREVALENT  
MID-LEVEL WARMTH SCENARIO.   
  
HOWEVER, STORM PERSISTENCE/DEVELOPMENT THROUGH THIS AFTERNOON WILL  
LIKELY REGIONALLY FAVOR THE COOLER SIDE OF THIS NOTABLE MID-LEVEL  
THERMAL GRADIENT, WITH MORE PROBABLE STORMS ACROSS DOWNSTATE  
PORTIONS OF ILLINOIS/INDIANA INTO KENTUCKY. IT IS PLAUSIBLE THAT A  
SEVERE RISK, AT LEAST ON AN ISOLATED BASIS, IMPACTS AT LEAST PARTS  
OF THE REGION THROUGH THE AFTERNOON INTO EVENING, WITH POTENTIAL  
LATE-NIGHT REDEVELOPMENT ON THE EASTERN EDGE OF THE CAP. DAMAGING  
WINDS AND LARGE HAIL WILL BE POSSIBLE IN WHAT COULD BE A  
MULTI-ROUND-RELATED STORM RISK FOR PARTS OF THE REGION.  
   
..VIRGINIA/NORTH CAROLINA  
  
A CLUSTER OF STRONG/SEVERE STORMS WILL CONTINUE TO IMPACT FAR  
SOUTHEAST VIRGINIA VICINITY THROUGH EARLY AFTERNOON. OTHERWISE, A  
RELATIVELY MOIST AND POTENTIALLY UNSTABLE AIR MASS IS PRESENT TO THE  
WEST OF THESE EARLY DAY STORMS. FORECAST SOUNDINGS SUGGEST  
SUFFICIENT DEEP-LAYER SHEAR FOR CONVECTIVE ORGANIZATION AND PERHAPS  
A SUPERCELL OR TWO. OVERALL, LOCALLY DAMAGING WINDS ARE THE MAIN  
THREAT THROUGH THE EARLY EVENING.  
  
..GUYER/LYONS.. 06/12/2022 

 

 

[ClicheVortex2014]

I’ve never seen 10k cape from a non-erroneous sounding. Granted, this probably won’t verify but still

 

[Chinook]

With regard to tomorrow (Monday) I can see how the models may have struggled to be consistent from the 00z runs to the 12z runs: 75-80 degree dew points in Indiana on the south side of the warm front. That's just super juice. As for now, the GFS favors some storms in mid-Wisconsin to mid-Michigan. The CAM models have essentially changed a lot of things since 00z. There's still some chance this could impact NW Ohio.

[snowlover2]

Storm just west of me about to move in here.

[snowlover2]

Quote

DAY 2 CONVECTIVE OUTLOOK    
NWS STORM PREDICTION CENTER NORMAN OK  
0104 PM CDT SUN JUN 12 2022  
  
VALID 131200Z - 141200Z  
  
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF  
THE NORTHERN PLAINS...AND ACROSS THE MIDWEST AND VICINITY...  
   
..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/EVENING.  
   
..NORTHERN PLAINS  
  
LARGE-SCALE UPPER RIDGING WILL PREVAIL ACROSS THE PLAINS STATES  
DURING THE PERIOD, AHEAD OF A SLOWLY ADVANCING UPPER TROUGH CROSSING  
THE INTERMOUNTAIN WEST.  THIS RIDGING/SUBSIDENCE SHOULD MAINTAIN  
CAPPING WELL INTO THE AFTERNOON WITHIN THE WARM SECTOR OF A  
DEVELOPING LOW OVER THE NORTHERN HIGH PLAINS REGION.  
  
HOWEVER, AS THE UPPER TROUGH ADVANCES AND ASCENT -- IMPLIED BY  
FALLING MID-LEVEL HEIGHTS -- COMMENCES BY LATE AFTERNOON/EARLY  
EVENING, ISOLATED TO SCATTERED STORM DEVELOPMENT IS EXPECTED FROM  
NORTHEASTERN WYOMING/SOUTHEASTERN MONTANA INTO THE WESTERN DAKOTAS.  
  
WITH STRENGTHENING MID-LEVEL SOUTHWESTERLIES ATOP LOW-LEVEL  
EASTERLIES NORTH OF THE DEVELOPING SURFACE LOW, SHEAR QUITE  
FAVORABLE FOR SUPERCELLS WILL SUPPORT UPDRAFTS THAT RAPIDLY ACQUIRE  
ROTATION.  AS A RESULT, AND GIVEN THE AMPLY UNSTABLE ENVIRONMENT,  
VERY LARGE HAIL WILL BE POSSIBLE, ALONG WITH RISK FOR LOCALLY  
DAMAGING WINDS AND A COUPLE OF TORNADOES.  STORMS WILL SPREAD  
NORTHEASTWARD THROUGH THE EVENING AND INTO THE OVERNIGHT HOURS  
ACROSS WESTERN AND NORTHERN SOUTH DAKOTA AND MUCH OF NORTH DAKOTA,  
WITH HINTS IN SOME MODELS OF UPSCALE GROWTH INTO BOWING CLUSTERS  
(WHICH COULD LOCALLY FOCUS GREATER WIND DAMAGE POTENTIAL).  
   
..UPPER MIDWEST EAST-SOUTHEASTWARD TO THE CENTRAL APPALACHIANS  
  
SUBSTANTIAL UNCERTAINTY EXISTS WITH RESPECT TO EVOLUTION OF  
CONVECTION, AND ASSOCIATED SEVERE POTENTIAL FROM THE UPPER MIDWEST  
EAST-SOUTHEASTWARD MONDAY, AS A MID-LEVEL DISTURBANCE/VORT MAX  
CRESTS THE RATHER STOUT UPPER RIDGE AND SLIDES EAST-SOUTHEASTWARD  
ACROSS THE UPPER -- AND EVENTUALLY THE LOWER -- GREAT LAKES REGION.  
  
UNCERTAINTY EXISTS EVEN AT THE START OF THE PERIOD, IN TERMS OF  
LOCATION AND COVERAGE OF ONGOING CONVECTION OVER THE MINNESOTA/IOWA  
VICINITY.  SOME SEVERE THREAT WILL LIKELY BE ONGOING, WITH A SHARP  
NORTHERN BOUNDARY TO THE RISK EXPECTED TO BE MAINTAINED THROUGH THE  
DAY WITH AN EAST-NORTHEAST TO WEST-SOUTHWEST WARM FRONT PROGGED TO  
LIE ACROSS SOUTHERN PORTIONS OF THE UPPER GREAT LAKES.  
  
AS THE AIRMASS NEAR AND SOUTH OF THE FRONT DESTABILIZES THROUGH THE  
DAY NEAR AND SOUTH OF THE FRONT, GRADUAL CONVECTIVE INTENSIFICATION  
IS EXPECTED, WITH WHATEVER LULL IN SEVERE RISK MAY EXIST EARLY ON  
DIMINISHING AS STORMS REDEVELOP/INTENSIFY THROUGH MID TO LATE  
AFTERNOON.  EVENTUALLY, MOST MODEL GUIDANCE AT LEAST LOOSELY AGREES  
THAT A FAST-MOVING, COMPACT, WELL-ORGANIZED MCS WILL EVOLVE.  GIVEN  
THE MOIST/UNSTABLE AIRMASS ALONG AND SOUTH OF THE FRONTAL ZONE, AND  
VERY STRONG/WEAKLY VEERING WESTERLY/WEST-NORTHWESTERLY FLOW WITH  
HEIGHT, DAMAGING WINDS APPEAR LIKELY, ALONG WITH HAIL AND EVEN A  
TORNADO OR TWO.  GIVEN THE STRENGTH OF THE FLOW ALOFT, AND POTENTIAL  
THAT A VERY WELL-ORGANIZED BOW EVOLVES, POTENTIAL FOR SIGNIFICANT  
GUSTS IS EVIDENT LOCALLY.  A NARROW CORRIDOR OF WIDESPREAD COVERAGE  
OF SEVERE GUSTS IS EXPECTED, THOUGH HIGHLIGHTING THIS CORRIDOR  
REMAINS DIFFICULT -- AS HIGHLIGHTED BY VARYING CAM OUTPUT.  UPGRADE  
TO ENH RISK MAY BE REQUIRED IN LATER OUTLOOKS, SHOULD THE PRIMARY  
CORRIDOR OF RISK BECOME MORE CLEAR WITH TIME.  STORMS SHOULD PERSIST  
INTO THE OVERNIGHT HOURS, AND POSSIBLY THROUGH THE END OF THE  
PERIOD, WITH THE EASTERN EXTENT OF THE RISK POTENTIALLY REACHING THE  
EAST SLOPES OF THE CENTRAL APPALACHIANS BY 14/12Z.  
  
..GOSS.. 06/12/2022 

 

 

[snowlover2]

Pouring buckets here.

[ClicheVortex2014]

WRT the new day 2… we’re still in a marginal risk for a reason. That reason isn’t because there’s gonna be storms other than the MCS. It’s because it’s plausible that anyone in the marginal risk in our region is still in the picture for now. The clouds that will turn into storms that congeals into the MCS probably haven’t even formed yet.

Edited June 12, 2022 by ClicheVortex2014

[StormfanaticInd]

13 minutes ago, ClicheVortex2014 said:

WRT the new day 2… we’re still in a marginal risk for a reason. That reason isn’t because there’s gonna be storms other than the MCS. It’s because it’s plausible that anyone in the marginal risk in our region is still in the picture for now. The clouds that will turn into storms that congeals into the MCS probably haven’t even formed yet.

I'm still trying to figure out today. Lol. Looks like storms will wait until tonight 

[ClicheVortex2014]

7 minutes ago, StormfanaticInd said:

I'm still trying to figure out today. Lol. Looks like storms will wait until tonight 

Hrrr isn’t handling the current storms well at all. Could also have an impact on the warm front.

[snowlover2]

18z HRRR has a couple differences from its 12z. First is the cluster of storms that moves through IA into south MN which becomes the MCS. 12z HRRR MCS came from the storms in N MN. The other is it turns more SE through more of Ohio.

[ClicheVortex2014]

17 minutes ago, snowlover2 said:

18z HRRR has a couple differences from its 12z. First is the cluster of storms that moves through IA into south MN which becomes the MCS. 12z HRRR MCS came from the storms in N MN. The other is it turns more SE through more of Ohio.

Not sure why it turned up into Wisconsin instead of following the gradient. But I’m not gonna question the physics of a model that has all known equations in it

[snowlover2]

18z NAM appears to be following the HRRR with the same differences from its 12z.

[snowlover2]

ILN latest.

Quote

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
351 PM EDT Sun Jun 12 2022

.SYNOPSIS...
Weak disturbances moving through an increasingly warm and moist
atmosphere will result in periodic chances of showers and
thunderstorms through Monday night. Heat will build quickly and
Tuesday and Wednesday will see the heat index rise above 100.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
An embedded disturbance will continue to move southeast to the
middle Ohio River Valley this evening. Meanwhile, a weak front
to our north will settle into the region tonight where it will
stall. The combination of these two features will result in the
likelihood of showers and storms across the northern/central
zones, and a chance of showers and storms over the southern
zones. Moderate instability (1000-1500 J/kg MLCAPE) and low end
moderate deep effective shear, will continue to pose an
isolated severe thunderstorm threat. Gusty to damaging winds
are the primary threat. The threat of severe storms should wane
later this evening as the disturbance moves away. For the
overnight hours, it appears the chance of showers/storms will
become more confined to locations along and south of the Ohio
River. Lows will range between 65 and 70.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
An anomalous mid level ridge to our southwest will begin to
build northeast into the Ohio Valley Monday into Monday night.
As this occurs, a warm front will merge with aforementioned
stall out boundary, pivoting north/northeast toward the southern
Great Lakes Monday night.

On Monday, uncertainty abounds in terms of convective evolution
and coverage during the day. Some models try to bring an MCV
from Missouri into the middle Ohio Valley where it tries to
develop into an MCS across parts of Kentucky. Confidence is low,
so at this point, a broad brush forecast with chance PoPs
associated with the advancing warm front has been employed.
Given increasing strong to extreme instability with dewpoints
pushing into the lower to mid 70s, along with continued ample
deep layered shear, thunderstorms may become severe with
damaging winds and large hail. Can not rule out isolated heavy
rainfall with pwats around 2 inches. Monday will see the
beginning of a period of very hot and humid weather. Have highs
ranging from the upper 80s northeast to the lower 90s along and
south of the Ohio River. With aforementioned dewpoints, this
will result in heat index values between 95 and 100, highest
over the south. This is just tickling Head Advisory criteria.
Will continue to mention this in the HWO product.

As we head into late Monday into Monday night, models still
show uncertainty in terms how a convectively enhanced
disturbance will propogate from the upper Mississippi River
Valley to the Great Lakes. There has been a general trend in the
models to move the feature a little bit farther north and east
from previous runs. This has been reflected in the latest SPC
SWODY2 Outlook, which now has our northern zones (west central
Ohio into central Ohio) still under a risk for severe storms.
Again, given the strong to extreme instability feeding into this
feature, we will have to monitor later model guidance. In fact,
some models develop a bowing like structure which would result
in a more widespread wind damage threat. Large hail will also be
a threat. Lastly, can not rule out isolated tornadoes given
veering profiles near the warm frontal boundary. These threats
continue in the HWO for the mentioned area. It will be warm and
muggy Monday night with lows only in the lower to mid 70s.

 

 

[snowlover2]

18z NAM

[snowlover2]

And then there's the 18z 3K NAM.

[Bradjl2009]

This sounds concerning.