1	NOAA’s National Weather Service Overview of Severe Weather Event on May 31, 2006
2	Goal of Overview Review radar signatures associated with severe weather reports Identify storm structures in beam blockage areas Review warm season radar rules of thumb with -20C, 0C, and 50 dBZ heights Look at null cases (future work with this event)
3	Pre Storm Environment
4	Pre Storm Review Albany sounding showed strong llvl cap, which mixed out as temps warmed into the 80s with dewpoints in the 60s Sfc based Cape near 2000 J/kg Limited speed shear, but some directional shear in the low levels High Cape/Low Shear Event PW’s around 1.10”, -20C=24.7kft, -0C=13.7kft
5	12z 250mb Analysis
6	12z 500mb Analysis
7	12z 850mb Analysis
8	SPC 12z Outlook
9	SPC 16z Discussion ...VT/NY... UPPER RIDGE OVER THE NORTHEAST HAS BEGUN TO FLATTEN TODAY...WITH WEAK WESTERLY FLOW ALOFT PRESENT ACROSS NY INTO NEW ENGLAND. WATER VAPOR IMAGERY HINTS AT A WEAK SHORTWAVE TROUGH MOVING ACROSS EASTERN ONTARIO...WHICH MAY HELP TO INITIATE SCATTERED THUNDERSTORMS THIS AFTERNOON. VERTICAL SHEAR REMAINS RATHER WEAK. HOWEVER...STRONG HEATING AND DEWPOINTS WELL INTO THE 60S...ALONG WITH 500MB TEMPERATURES BELOW -10C WILL DESTABILIZE AIR MASS AND LEAD TO SCATTERED STORMS. HAIL AND GUSTY WINDS ARE POSSIBLE IN STRONGER CELLS.
10	18z Surface Map
11	Radar Signature Review
12	Newport Storm in northern Orleans County at 2009Z (Scans 1.3, 2.4, 3.4, 4.0)
13	Newport Storm (Base Reflectivity at 6.0 degree slice) at 2009Z
14	Newport Storm at 2009Z
15	Newport Storm Top Divergence at 8.0 Degree Slice at 2009Z
16	Radar Review for Newport Storm 55 dBZ at 34 kft with 60 dBZ up to the -20C isotherm Storm Top Divergence >75 knots VIL density=3.60 5 to 7 km core of 55 to 65 dBZ btwn 0C and -20C isotherm
17	The End Result Hail near Newport
18	Island Pond Storm in western Essex County, VT Reflectivity Cross Section at 2101Z
19	Island Pond Storm in western Essex County, VT Velocity/Reflectivity 5.1 slice at 2109Z
20	Island Pond Storm in western Essex County, VT Reflectivity 5.1 slice at 2109Z
21	Island Pond Storm in western Essex County, VT at 2105Z 4 elevation scans (1.3, 2.4, 3.1, 4.0)
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23	Island Pond Storm in western Essex County, VT Storm Summary 50 dBZ to 34kft 65 dBZ to 24.5 kft Depth of 50 dBZ core > 8km Storm Top Divergence near 100 knots Wind damage reported in Canaan and near Island Pond, VT
24	Lower Waterford southeast Caledonia County Lowest 4 scans (0.5,0.9, 1.3, 1.8) at 2122z
25	Lower Waterford southeast Caledonia County (1.5,2.4, 3.4,4.3) at 2114z
26	Lower Waterford southeast Caledonia County (Scan 8.0 degrees at 2114Z) Total Storm Top Divergence near 55 knots
27	Lower Waterford southeast Caledonia County Storm top divergence near 55 knots 50 dBZ around 24kft Wind damage reported near Lower Waterford Bow like structure with reflectivity…but no MARC signature (Needed Velocity Cross Section) Storm beam blocked in lowest 3 elevation scans
28	Part 2 Clinton, Essex, and Addison Counties Convection Overall, the storms were pulse like storms within a broken line of convection High instability and low shear environment (2000 j/kg and 0-6km shear < 15 knots) Convective updrafts were 5 to 15 nm wide and only lasted 20 to 30 minutes before dissipating Verification was limited to do location of storms and no spotters in the vicinity (i.e. southern/central Essex County, NY and western Clinton County, NY Addison County Storm collapsed/weakened before entering the county and did not produce any severe weather reports
29	Clinton County Storm near Claysburg at 1659Z (User Layer Ref 25kft-35kft, VIL, ET, and STP)
30	Clinton County Storm near Plattsburgh at 1733Z (User Layer Ref 25kft-35kft, VIL, ET, and STP)
31	Cross Section near Clayburg in Clinton County at 17z
32	Clayburg Storm at 1703z
33	Clinton County Storm Review 60 to 65 dBZ core to 21 kft VIL density 4.60 Three Body Scatter Spike noticed on cross section near Clayburg 25kft to 35kft dBZ core of 62 Nickel sized hail reported in PLB at 1740z (Several miles from core of highest reflectivity signatures)
34	Essex County New York Storms near Newcomb Storms passed just north and east of Newcomb No spotters and very rural location Very intense storms with ET’s>50kft, VIL near 65, and high reflectivity cores
35	Essex County New York Storms near Newcomb at 1750Z
36	Essex County New York Storms near Newcomb at 1750Z Velocity 12.5 Scan
37	Essex County New York Storms near Newcomb at 1750Z Reflectivity Scan 12.5 (green stars indicate spotters)
38	Essex County New York Storms near Elizabethtown at 1837Z
39	Essex County New York Storms near Elizabethtown at 1837Z Velocity 12.5 Scan
40	Essex County New York Storms near Elizabethtown at 1837Z Reflectivity Scan 10.0
41	Essex County New York Storms near Elizabethtown at 1837Z Reflectivity Scan 12.5
42	Essex County New York Storms near Elizabethtown Large Storm with wide updraft/reflectivity core (4-8nm wide) 50 dBZ core to 38 kft Storm Top Divergence near 80 knots VIL Density near 4.38 VIL=69…..ET=52kft No severe reports…because of location and no spotters
43	Western Addison County Storms at 1907Z
44	Western Addison County Storms at 1907Z
45	Western Addison County Storm Review Storm collapsed while crossing the CPV (cooler lake water environment…less instability) 50 dBZ only to 22kft (not reaching the -20C isotherm VIL density only 3.49 (Consider Issuing Warning) Decreasing reflectivity core aloft and limited width