The following severe weather checklist was developed for NWSO SGF, but can be used for the much of the Midwestern and southern United States. Local adaptations due to elevation, terrain and other local and regional factors must be made to fit a particular location. After a detailed surface and upper air analysis, one should proceed to this checklist (Table 1).
If six or more positive (or yes) parameters, proceed to the Miller/SPC checklist. In addition, calculate the wind index (WINDEX), and the height wet bulb zero (WBZ). If less than six positive parameters, there will probably not be organized severe weather in your area. One word of caution: Be vigilant for elevated convection above an elevated capping inversion. If your analysis reveals a stable atmosphere in the lower levels but has moisture above a fairly strong inversion, recalculate the indices above the inversion or check for steep mid level lapse rates. See section 8A for more information on elevated convection. One last word of caution: Beware of rapidly changing synoptic environments.
TABLE 1 NWSO Springfield Severe Weather Checklist 

Weather Parameter 
Indicators (Circle Letter) 
Favorable



Low Level Temperature and Moisture  A. Depth of low level moisture now (or expected) to be greater than 3000 ft? B. Surface dew point >60°F? C. Distinct low level surface moisture axis present? Location/Time? D. Low level moisture convergence expected? Location/Time? E. Will the 850 mb max temperature ridge be over or west of the 850 mb moisture axis? F. Will temperature exceed computed convective temperature? 

2.  Low Level Jet  A. Is a low level jet present or expected to develop? Location/Time? B. Highest 850 mb jet speed expected over CWA. C. 850mb moisture convergence expected? Location/Time? 

3.  Upper Level Support  A. Will there be a 300/250 mb jet >65 kts. B. Ageostrophic circulation expected? Location? C. Coupled jet expected? Location? 

4.  Lifting Mechanisms  A. Are any lifting mechanisms such as fronts or outflow boundaries present? List them along with their location. B. Will any intersecting boundaries be present? Location? C. Will lifting mechanisms be able to overcome capping inversion (generally if cap strength < 2°F and CIN <50 J/kg. Also note severe storms can develop regardless of CAP strength, "if" sufficient dynamic strength is available.)? 

5.  Vertical Wind Shear  A. Will winds show significant veering (03km shear values > 35kts)? B. Is there (or will there be) speed shear >25kts and/or directional shear >30 degrees between 850 and 500 mb? 

6.  Instability  A. Is/will the Lifted Index be 0? B. Is/will the K Index be >30? (Can be as low as 2025 with elevated convection.) C. Will CAPE >800 J/kg? D. Will there be high mid level lapse rates (700500 mb) > or = 6.5°C/km? E. Will there be warm advection at 850 mb? F. Will a significant capping inversion remain in place? 

7.  700 mb Dry Intrusion  A. Is there or will there be a dry intrusion of air at or near the 700 mb level? (Dew point depression >6°C.) 

8.  Upper Vertical Motion  A. Is large scale forcing indicated by model Q vector and omega fields? B. Will there be significant PIVA/Differential PVA? 

9.  Satellite Imagery/Cloud Indicators  A. Are there lines of cumulus or mid clouds (altocumulus castellanusACCAS) on the morning satellite imagery? B. Does satellite imagery indicate a short wave moving into the area with corresponding significant height falls on upper air analysis? C. Is there significant mid level drying present on water vapor imagery? 

10.  Surface Pressure Falls  A. Is there or will there be strong surface pressure falls B. If 10A is yes, will there be a corresponding pressure rise moving toward the fall area? (The larger the absolute value of this risefall couplet, the larger the potential for severe weather in the pressure fall area.) 

TABLE 2 Severe Weather Checklist (After SPC (1998) and Miller (1972)) 

PARAMETER 
WEAK 
MODERATE 
STRONG 
Surface Pressure  >1010 mb  1010 to 1005 mb  <1005 mb 
Surface Dew Point  <55°F  5564°F  >or = 65°F 
12hr Surface Pres Change  0 to 3   4 to 7  < or = 8 
850 mb Temp Axis  East of Moist Axis  Over Moist Axis  West of Moist Axis 
850 mb Jet  <25 kts  2535 kts  >35 kts 
850 mb Dew Point  < or = 8°C  8  12°C  >12°C 
700 mb Dry Intrusion  N/A or Weak 700 mb winds  Winds from dry to moist intrude at <40° and are > or = 15 kts  Winds intrude at an > or = 40° and are > or = 25 kts 
700 mb Temp No Change Line  Winds cross line< or = 20°  Winds cross line >20° and < or = 40°  Winds cross line >40° 
500 mb Height Change  < 30 m  > or = 30 and < or = 59 m  > or = 60 m 
500 mb Wind Speed  < or = 35 kts  3649 kts  > or = 50 kts 
500 mb Vorticity Advection  Neutral or NVA  PVAContours Cross Vorticity Pattern < or = 30°  PVAContours Cross Vorticity Pattern >30° 
850500 mb Wind Shear

1525 kts 
2635 kts 
>35 kts 
300200 mb Jet  < or = 65 kts  6685 kts  >85 kts 
Mean R.H.  7080% or 4050%  5070%  5070% 
TT  <50  5055  >55 
LI  >2  3 to 5  < or = 6 
CAPE  8001500 J/kg  15002500 J/kg  >2500 J/kg 
SWEAT  <300  300500  >500 
WBZ  >11000 ft <5000 ft 
900011000 ft 50007000 ft 
70009000 ft 
Helicity (03km)  150300 m^{2}/s^{2}  300450 m^{2}/s^{2}  >450 m^{2}/s^{2} 
SSI  1 to +2  1 to 3  <3 
The rest of this paper contains various weather checklists, rules of thumb, and other severe weather information. Forecasting large hail, strong winds, tornadoes, derechos, and pattern recognition are examined.
This paper will not address radar techniques applicable to severe weather. An excellent compendium of WSR88D weather reference materials is by Falk (1997).