Jul 15, 2020 2000 UTC Day 1 Convective Outlook
Updated: Wed Jul 15 19:52:33 UTC 2020 (20200715 2000Z Day 1 shapefile | 20200715 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20200715 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 24,945 3,707,867 St. Louis, MO...Springfield, IL...St. Charles, MO...St. Peters, MO...Florissant, MO...
SLIGHT 91,813 3,504,210 Colorado Springs, CO...Amarillo, TX...Peoria, IL...Pueblo, CO...Columbia, MO...
MARGINAL 247,795 25,432,509 Chicago, IL...Milwaukee, WI...New Orleans, LA...Madison, WI...Baton Rouge, LA...
Probabilistic Tornado Graphic
20200715 2000 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 30,076 4,197,011 St. Louis, MO...Springfield, IL...Decatur, IL...Bloomington, IL...St. Charles, MO...
2 % 38,936 2,838,313 Peoria, IL...Columbia, MO...Champaign, IL...Terre Haute, IN...Urbana, IL...
Probabilistic Damaging Wind Graphic
20200715 2000 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
30 % 24,945 3,707,867 St. Louis, MO...Springfield, IL...St. Charles, MO...St. Peters, MO...Florissant, MO...
15 % 91,776 3,503,517 Colorado Springs, CO...Amarillo, TX...Peoria, IL...Pueblo, CO...Columbia, MO...
5 % 247,128 25,400,082 Chicago, IL...Milwaukee, WI...New Orleans, LA...Madison, WI...Baton Rouge, LA...
Probabilistic Large Hail Graphic
20200715 2000 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 60,541 4,207,883 Colorado Springs, CO...St. Louis, MO...Pueblo, CO...Columbia, MO...St. Charles, MO...
5 % 159,928 19,224,003 Chicago, IL...Milwaukee, WI...Madison, WI...Amarillo, TX...Aurora, IL...
   SPC AC 151952

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0252 PM CDT Wed Jul 15 2020

   Valid 152000Z - 161200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE MID MS VALLEY...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE SOUTHERN/CENTRAL HIGH PLAINS...

   ...SUMMARY...
   Severe storms are expected this afternoon and evening across parts
   of the mid Mississippi Valley, with damaging winds, large hail, and
   a few tornadoes possible. Other severe storms are expected across
   the south-central High Plains this afternoon and evening.

   ...20Z Update...
   No major changes have been made to the Enhanced Risk across the mid
   MS Valley or the Slight Risk across the southern/central High
   Plains. Severe probabilities have been reduced across west-central
   MO behind a northeastward-moving MCV and associated convection. See
   recently issued Tornado Watch 373 and Mesoscale Discussions 1233 and
   1234 for more information on the short-term severe threat across the
   mid MS Valley.

   Convection is increasing in coverage and intensity across
   southeastern CO and vicinity. See Mesoscale Discussion 1235 for
   additional details on the near-term severe threat across this
   region.

   ..Gleason.. 07/15/2020

   .PREV DISCUSSION... /ISSUED 1148 AM CDT Wed Jul 15 2020/

   ...Midwest including Missouri/Illinois...
   A readily apparent MCV near the Kansas City area at late morning
   will continue generally eastward toward southern Illinois by this
   evening. Preceding convection to its east/northeast continues to
   effectively reinforce a cold pool/front that will demarcate the
   latitudinal extent of the primary severe risk especially across
   Missouri, with warm sector dewpoints otherwise ranging from the
   middle/upper 60s F in central Illinois to lower/mid 70s across
   central/eastern Missouri. As cloud cover continues to thin/disperse
   across the warm sector, a corridor of strong destabilization (MLCAPE
   of 2500-3500 J/kg) is expected this afternoon near/south of the
   outflow from south-central Missouri toward the greater Saint Louis
   area/southwest Illinois. 

   Thunderstorm development/intensification is still expected by around
   mid-afternoon, initially across central/east-central Missouri toward
   far western Illinois. Strong mid-level winds are associated with the
   MCV (reference regional WSR-88D VWP data) and some enhancement of
   low-level winds also exists along the southeast flank of the MCV.
   This will contribute to an environment supportive of initial
   supercells, and a gradual evolution of another larger storm cluster
   from eastern Missouri into Illinois later this afternoon and
   evening. The potential will exist for damaging winds and a couple of
   tornadoes. Although mid-level lapse rates are not steep, some severe
   hail may occur as well, mainly with the initial supercell modes.

   ...Southern High Plains...
   An outflow-reinforced front has moved southward and generally
   stalled across northeast/east-central New Mexico and Texas South
   Plains. Low-level flow will become more easterly/upslope through the
   day from northeast New Mexico into southeast Colorado, which will
   again support thunderstorm development this afternoon on the Front
   Range/Raton Mesa vicinity. This will include initial supercells
   capable of producing large hail, given MLCAPE in excess of 2000 J/kg
   with steep mid-level lapse rates and effective bulk shear of 30-40
   kt. Convection will likely grow upscale into an
   east/southeastward-moving cluster or two capable of producing
   damaging winds this evening as it persists into and across parts of
   the Oklahoma/Texas Panhandles.

   ...Southeast Wisconsin to northern Lower Michigan today...
   Related to the persistent MCS/MCV across the middle Mississippi
   Valley, residual cloud cover will tend to hinder surface heating and
   overall destabilization this afternoon near the
   southwest/northeast-oriented front across the region. Regardless,
   some increase in convective coverage and intensity can be expected
   this afternoon, with some potential for isolated damaging
   thunderstorm wind gusts and possibly some hail, particularly if
   cloud breaks materialize later today. 

   ...Gulf Coast including parts of LA/MS/AL and FL Panhandle...
   A weak mid-level trough over the north central Gulf coast, along
   with daytime heating and local sea breeze circulations, will
   continue to support scattered thunderstorm development this
   afternoon. Strong downburst winds may occur with the strongest
   storms through the diurnal heating cycle, with localized wind damage
   a possibility.

   ...Florida Peninsula...
   A few stronger/perhaps locally severe thunderstorms could occur this
   afternoon, mainly across interior/western portions of the southern
   Florida Peninsula. Within a moist air mass, steep low-level lapse
   rates and slightly cooler mid-level temperatures may contribute to
   wet microburst potential.

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