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3	WHY FORECAST SEVERE (CONVECTIVE) WEATHER? Entire nation affected throughout the year ~ 400 deaths and ~ $2–5 billion damage in U.S. annually ~ 80% of presidential disaster declarations annually
4	SEVERE CONVECTIVE WEATHER INCLUDES MORE THAN TORNADOES… Hail (3/4 in. or greater) High Winds (58 mph or greater) Lightning (2^nd leading killer) Flash flooding (#1 killer; ~ 100 U.S. deaths annually)
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7	SOME STORM “INGREDIENT SOURCES” INCLUDE :
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11	SUSTAINED CONVECTION REQUIRES ONE ADDITIONAL INGREDIENT: VERTICAL SHEAR
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17	THE FORECAST PROCESS
18	The relative value of different methods used to determine trend varies over forecast range...
19	CLIMATOLOGY PROVIDES A START
20	NUMERICAL MODEL GUIDANCE
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25	NUMERICAL GUIDANCE : Data Display
26	NUMERICAL GUIDANCE : Calibrated ensemble forecasts
27	NUMERICAL GUIDANCE : Calibrated ensemble forecasts
28	NUMERICAL GUIDANCE : Calibrated ensemble forecasts
29	NUMERICAL GUIDANCE : Calibrated ensemble forecasts
30	CONCEPTUAL MODELS : Mid-Latitude meteorology
31	CONCEPTUAL MODELS AID DIAGNOSIS …but must be used carefully
32	CONCEPTUAL MODELS ARE UPDATED AND “LINKED” …as experience and physical understanding grow
33	COMPOSITE CHARTS : Combine information derived from observations and numerical guidance with conceptual models
34	DIAGNOSIS – THE FIRST STEP IN FORECASTING
35	SUNDAY 4 MAY 2003 : High Risk over the Central Plains
36	SUNDAY 4 MAY 2003 : High Risk over the Central Plains
37	SUNDAY 4 MAY 2003 : High Risk over the Central Plains
38	SUNDAY 4 MAY 2003 : High Risk over the Central Plains
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50	ANALYSIS OF SOUNDING (“RAOB”) DATA
51	“UNABRIDGED” RAOB DATA DISPLAY
52	RAOB ANALYSIS : THERMODYNAMIC DATA …using a Skew T - Log P chart
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56	RAOB DATA : Comparing Skew T plots with the real world
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58	RAOB SEQUENCE #1 – THERMODYNAMIC EVOLUTION AT TOPEKA, KS
59	RAOB SEQUENCE #1 – THERMODYNAMIC EVOLUTION AT TOPEKA, KS
60	RAOB SEQUENCE #1 – THERMODYNAMIC EVOLUTION AT TOPEKA, KS
61	RAOB SEQUENCE #1 – THERMODYNAMIC EVOLUTION AT TOPEKA, KS
62	RAOB SEQUENCE #2 – THERMODYNAMIC EVOLUTION AT SPRINGFIELD, MO
63	RAOB SEQUENCE #2 – THERMODYNAMIC EVOLUTION AT SPRINGFIELD, MO
64	RAOB SEQUENCE #2 – THERMODYNAMIC EVOLUTION AT SPRINGFIELD, MO
65	RAOB SEQUENCE #2 – THERMODYNAMIC EVOLUTION AT SPRINGFIELD, MO
66	RAOB SEQUENCE #2 – THERMODYNAMIC EVOLUTION AT SPRINGFIELD, MO
67	(Back to our) “UNABRIDGED” RAOB DISPLAY
68	RAOB ANALYSIS : FOCUS ON KINEMATIC DATA …using either conventional wind profiles or hodographs
69	THE HODOGRAPH …a graphical tool used to evaluate vertical wind shear
70	THE HODOGRAPH …additional examples showing how different wind profiles yield wide variations in hodograph shape
71	Recall origin of supercell development with a straight hodograph :
72	When the hodograph curves clockwise with height, the right-moving storm is favored for sustained growth / longevity :
73	RAOB ANALYSIS : KINEMATIC DATA Comparison of conventional wind profile to hodograph
74	RAOB ANALYSIS : KINEMATIC DATA Connecting tips of plotted wind vectors to yield hodograph curve
75	RAOB ANALYSIS : KINEMATIC DATA Plotting observed (or estimated) storm motion
76	RAOB ANALYSIS : KINEMATIC DATA Determining storm-relative flow
77	RAOB ANALYSIS : KINEMATIC DATA Graphical depiction of Storm-relative helicity (SRH)
78	RAOB ANALYSIS : KINEMATIC DATA Graphical depiction of Storm-relative helicity (SRH) – Part 2
79	RAOB ANALYSIS : KINEMATIC DATA Summary of hodograph analysis
80	RAOB SEQUENCE #3 – KINEMATIC EVOLUTION AT SPRINGFIELD, MO
81	RAOB SEQUENCE #3 – KINEMATIC EVOLUTION AT SPRINGFIELD, MO
82	RAOB SEQUENCE #3 – KINEMATIC EVOLUTION AT SPRINGFIELD, MO
83	RAOB SEQUENCE #3 – KINEMATIC EVOLUTION AT SPRINGFIELD, MO
84	RAOB SEQUENCE #3 – KINEMATIC EVOLUTION AT SPRINGFIELD, MO
85	RAOB DATA DO NOT TELL THE WHOLE STORY …storm mode must be considered when analyzing severe threat
86	SUBJECTIVE “SURFACE” ANALYSIS Why it is essential to severe weather forecasting :
87	SUBJECTIVE ANALYSIS HELPS DIAGNOSE A POORLY-FORECAST BOUNDARY AND SURFACE WAVE …a system that was responsible for 50 tornadoes, including 2 F3s
88	BOUNDARIES ARE AMONGST THE MOST IMPORTANT FEATURES TO BE DIAGNOSED BY SUBJECTIVE ANALYSIS
89	BOUNDARY DETECTION IS FACILITATED BY DATA SYNTHESIS
90	…and by use of extended animations
91	OBJECTIVELY-DERIVED FIELDS PROVIDE VALUABLE ASSISTANCE WITH SUBJECTIVE ANALYSIS
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