The April 28, 2011 Severe Weather and Flash Flood Event
description
Transcript of The April 28, 2011 Severe Weather and Flash Flood Event
![Page 1: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/1.jpg)
The April 28, 2011 Severe Weather and Flash Flood Event
Mike Evans / NWS Binghamton, NY
![Page 2: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/2.jpg)
Outline
Large-scale pattern / meso-analysisRadar dataHigh resolution model outputSummary
![Page 3: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/3.jpg)
500 mb heights and vorticity
![Page 4: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/4.jpg)
Surface plot – 09z
![Page 5: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/5.jpg)
Equivalent potential temperature, omega and wind speed cross section – 12z
![Page 6: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/6.jpg)
SPC surface and 700 mb frontogenesis – 09z
![Page 7: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/7.jpg)
SREF CAPE and 850 hPa wind
![Page 8: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/8.jpg)
SPC analysis 0-1 km shear and significant tornado parameter
![Page 9: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/9.jpg)
SPC Guidance
![Page 10: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/10.jpg)
Reflectivity and storm relative motion 0522 – 0540 UTC
![Page 11: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/11.jpg)
Reflectivity and storm relative motion 0654 – 0830 UTC
![Page 12: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/12.jpg)
Reflectivity and storm relative motion 0945 UTC
![Page 13: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/13.jpg)
13
T-9 T-8 T-7 T-6 T-5 T-4 T-3 T-2 T-1 T-000.10.20.30.40.50.60.70.80.9
1
Verified Median NROT (Supercell tornadoes; Tim Humphrey)
.5 NROT
.9 NROT1.4 NROT1.9 NROT
NR
OT
![Page 14: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/14.jpg)
14
T-5 T-4 T-3 T-2 T-1 T-00
0.2
0.4
0.6
0.8
1
1.2
Verified Median NROT (QLCS tornadoes; Tim Humphrey)
.5 NROT
.9 NROT1.4 NROT1.9 NROT
NR
OT
![Page 15: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/15.jpg)
Normalized rotation – Erin tornado (QLCS)
![Page 16: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/16.jpg)
Normalized rotation – Danby tornado(QLCS – broken S)
![Page 17: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/17.jpg)
Normalized rotation – Pharsalia tornado (mini-supercell)
![Page 18: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/18.jpg)
Normalized rotation – McDonough tornado (mini-supercell; range folding)
![Page 19: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/19.jpg)
Normalized rotation – Columbus tornado (mini-supercell; RFD spin-up)
![Page 20: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/20.jpg)
Normalized rotation – Herrick tornado(QLCS)
![Page 21: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/21.jpg)
Severe reports
![Page 22: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/22.jpg)
BGM CWA tornado climatology
![Page 23: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/23.jpg)
High resolution model 1 km AGL reflectivity – valid 09z
![Page 24: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/24.jpg)
High resolution model 1 km AGL reflectivity – valid 12z
![Page 25: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/25.jpg)
HRRR 1 km AGL reflectivity valid 08z
![Page 26: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/26.jpg)
SummaryTornadoes and flash floods affected central
New York and northeast Pennsylvania during the early morning on the 28th.
This was only the 2nd time since the late 1990s that a tornado was reported in our area between midnight and 9 am.
Tornadoes occurred with a variety of convective storm structures and a variety of rotational evolution patterns.
![Page 27: The April 28, 2011 Severe Weather and Flash Flood Event](https://reader036.fdocuments.net/reader036/viewer/2022062410/56815abc550346895dc87c6e/html5/thumbnails/27.jpg)
Summary continued00z hi resolution model runs forecast a
variety of structures; mostly broken lines of convection, composed of small line segments and some individual cells.
The 00z HRRR model was too weak with the line (especially over NY), but subsequent runs trended toward a better forecast.
All of the 00z models were too far west (too slow) with the convection from 06z through 12z.