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DAY 1 CONVECTIVE OUTLOOK

Welcome to the "new day one convective outlook! We have added a few new features, and are providing HD or "high Definition" graphics to the product. This should help bolster increased usefulness and accuracy of the chart graphics. Overall, this new day one outlook should prove helpful and useful for our clients and other users. Should you still have any questions or concerns about this product, please feel free to contact us!


THE OUTLOOK DETAILS AT A GLANCE

The following section will pretty much remain as it appears on our current operational day 1 outlook. Some of the graphics have been enhanced.

Categorical Risk
No Risk Indicated
Sub-Severe Storms
Limited Risk
Slight Risk
Elevated Risk
Moderate Risk
High Risk

Convective Mode(s)
None
Linear (Squall Line)
Multicelluar
QLCS (Quasi-Linear Convective System)
Supercells
Mixed Mode(s)
Diurnally Driven Sub Severe Storms

Convective Initiation (Timing)
None
By or after 10 am
By or after 1 pm
By or after 4 pm
By or after 7 pm
Storms in Progress

Convective Coverage
None
Widely Isolated
Isolated
Widely Scattered
Scattered
Numerous
Widespread

Convective Probabilities
(Large Hail/Damaging Winds)
5 percent
15 percent
25 percent
40 percent
55 percent
60 percent or greater
None
Convective Probabilities
(Tornadoes)
2 Percent
6 Percent
12 Percent
20 Percent
35 Percent
50 Percent
None

FORECAST AT A GLANCE

The following "meters" will breakdown not only the categorical risks, but also show the forecast severe weather probabilities for each of the three primary elements (i.e. large diameter hail, damaging winds, and tornadoes). This should increase usefulness and promote a better understanding of those elements to be expected.

CATEGORICAL RISK

LARGE HAIL POTENTIAL

DAMAGING WIND POTENTIAL
TORNADO POTENTIAL

2000 UTC DAY 1 SEVERE WEATHER OUTLOOK GRAPHICS

Categorical Tornado Damaging Winds Large Hail
 Population  Cities/Towns  CWAs  Interstates  Counties




SCO RAC 49938

DAY 1 CONVECTIVE OUTLOOK  
SCO/MIDWEST WEATHER SERVICE STEVENS POINT/WHITING WI
228 PM CDT FRI JUL 19 2019

Please note: Refer to the  general thunderstorm outlook  product for all general and/or sub-severe forecast information. 

SUMMARY OF THE 2000 UTC...300 PM CDT INFORMATION: Summary... Widespread thunderstorms are forecast later this afternoon and tonight across the coverage region. Widespread severe thunderstorms, posing all facets of severe weather appears likely from central Minnesota east into northern and central Wisconsin, where the potential exists for widespread damaging winds (Derecho events), and significant tornadoes. A few cities which may be impacted include Wausau, Rhinelander, Merrill, Antigo, Marshfield, Stevens Point, and Wisconsin Rapids. Severe Thunderstorm Forecast Discussion... 20Z Update... A warm front extended from a surface low now invoc KMKT into western and central Wisconsin. South of this boundary, a very hot and humid air mass was in place across southern MN/WI. With ongoing diabatic surface heating taking place, lapse rates have soared well above 8.5 degrees C over much of central MN east into WI. This is resulting in MLCAPES AOA 5500 j/kg across these areas along with very favorable vertical shear profiles. As a result, severe thunderstorms have developed across parts of northcentral MN east into parts of northwest WI. Additional thunderstorms are likely into the late afternoon, with additional watches likely to be issued. Have made only minor changes to the previous outlook charts/forecast reasoning. Previous discussion issued at 1044 AM CDT... A convective cluster is ongoing across north-central SD aided by warm moist advection around 700 mb along a pronounced baroclinic zone. 00Z CAM guidance had a decent handle on this activity earlier this morning and are consistent with a decaying trend through late morning as advection shifts east amid pronounced MLCIN as sampled by the 12Z Aberdeen sounding. There is a low confidence scenario that a strong enough cold pool is becoming established with this early day cluster such that total decay does not occur. If this occurs, robust boundary-layer heating downstream may be sufficient for an increasing threat during the afternoon of strong to severe wind gusts. This could still yield a scattered to widespread damaging wind scenario, albeit in an earlier time frame than progged by guidance. The more probable scenario is for an extremely unstable air mass (MLCAPE > 5500 J/kg) to become established to from southeast SD through central/southern WI as the elevated mixed layer overspreads surface dew points rising into the mid to upper 70s. A surface cyclone over central SD should track towards the Twin Cities through early evening. Strong low level convergence near andnortheast of this cyclone along the warm front should sustain surface based storm development across central into east-central MN. Once initiation occurs, intense supercells will develop rapidly, with an attendant threat for all severe hazards including strong tornadoes amid 50-60 kt effective shear and 0-3 km SRH > 300 m2/s2. The very warm moist thermodynamic profiles will also support generation of strong cold pools which should eventually yield a bowing, forward propagating MCS across northern WI into parts of northern Lower and Upper MI. Strength of the vertical shear suggests the potential for intense bowing segments capable of yielding a derecho with significant severe wind gusts. ...Maximum Risk By Hazard... Tornadoes: 12% - Elevated Damaging Winds: 40% - Moderate Large Hail: 15% - Slight Areas of widespread dangerous weather potential... Parts of northern and central Wisconsin. Portions of central and east-central Minnesota. A part of western lake Michigan. Refer to the latest situation report for the latest short term discussion texts. Next Update... The next forecast update is scheduled for 0100 UTC. Forecaster: Clark

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