National Weather Service United States Department of Commerce

 

April 9, 2015 Tornado and Wind Damage

 

Map of Tornado Tracks 

Damage Survey Results

Storm Reports

Precipitation Totals

Radar Loops of Event

Outlooks & Warnings

Event Overview


 

Interactive Google Map to come soon.

 


 

Damage Survey Reports

Pockets of wind damage occurred across portions of far southern Lower Michigan as well as northwestern Ohio in the vicinity of a warm front that help with thunderstorm organization. The most concentrated swath of damage occured in northern HIllsdale county, north of Moscow, MI. Widespread wind damage was reported across much of the area. NWS damage survey teams traveled across the region to survey areas of extensive damage. The final results of the surveys are below. 

Click on the hyperlink for information on the EF0 tornado, including path maps, radar images, and photos. Additional storms reports for the rest of the area can be found below under Storm Reports.

 

Hillsdale County MI: EF0 (click for more information)

 

 


Storm Reports

To see a detailed list of every storm report, please click here to view a PDF.


Precipitation Totals


Radar Loops

Click on the images below to enlarge (could take a few minutes to load)

KIWX WSR-88D Reflectivity Loop - 11/17/2013 beginning 2:25 PM EST & ending 4:26 PM EST

KIWX WSR-88D Storm Relative Velocity Loop - 11/17/2013 beginning 2:25 PM EST & ending 4:26 PM EST

 The map below shows a plot of rotation tracks based off of NWS Doppler Radar.


Outlooks and Warnings

 

Storm Prediction Center Day 1 Outlook Issued Sunday Morning

 

Storm Prediction Days 2-4 Outlooks

Issued Thursday (Nov 14th) for Sunday

Issued Friday (Nov 15th) for Sunday

Issued Saturday (Nov 16th) for Sunday

 

NWS Warnings Issued on November 17, 2013
National Local (NWS IWX)

The animated loop below shows regional warnings overlayed on the radar reflectivity.



What Caused This Outbreak?

 A strong low pressure system moved through the region on November 17, 2013. Storms began to fire in central Illinois ahead of a strong cold front during the early afternoon hours and quickly reached severe limits. Initially, the storms fired as distinct supercells moving at  forward speeds of 50-60 mph! Eventually, the supercells merged into a squall line that raced across Indiana and into Ohio during the late afternoon to early evening hours.

The setup was ideal for severe weather, not to mention a widespread outbreak with multiple tornadoes. To sustain themselves and become severe, thunderstorms need heat and moisture (which creates instability), wind shear (strong winds that change direction with height), and forcing (such as a cold front). Environments necessary for thundstorms are typically found in the Midwest from late spring through summer, but a secondary peak in severe weather does occur in the fall. For this particular event, there was enough instability and strong wind shear present ahead of a strong cold front to produce thunderstorms that quickly became severe. These parameters were extremely high for any time of the year, especially the fall, so long-lived and significant tornadoes occurred across the region.

The images and descriptions below gave a depiction of the mesoscale atmospheric conditions present at 3 pm EST (20Z) on Sunday, November 17, 2013.

 

Surface analysis (21Z) shows a cold front entering the area from the west with a low pressure center across northern Michigan. Surface dew points ahead of the front were in the 60s providing moisture to fuel the thunderstorms. 850 mb analysis shows a low-level jet (~50-65 kts) pumping warm, moist air into the area ahead of a low pressure center. This helped to fuel and sustain thunderstorms as they developed in central IL and moved into the local area. 500 mb analysis shows a mid-level trough of low pressure just to the west of the local area. This, coupled with a mid-level jet stream rounding the base of the trough, provided forcing for the thunderstorms to fire to the west before moving into the local area.

 

Effective Bulk Shear: A measure of the difference between winds at the surface and aloft in the atmosphere. Supercells become more probably as the effect bulk shear vector increases in magnitude through the range of 25-40 kt and greater. Values across the local area were in the 60-70 kt range, which is quite impressive! 0 - 1 KM Storm Relative Helicity (SRH): SRH is a measure of the potential for rotating supercells. Values of 0-1km SRH greater than 100 m2/s2 suggest increased threat of tornadoes with supercells. Values across the local area were in the 400-600 m2/s2 range with storm motion of 50-55 kts! Significant Tornado Parameter (STP) : The STP is a multi-ingredient index that is calculated to determine the potentital for significant (EF2+) tornadoes. A majority of sig. tornadoes have been associated with values greater than 1. STP values across the local area were 1-2.

 


Updated 03/18/2014 11am
LWF/KG/NG/CEO

 

 

 

 

 

Below is a PNS discussing the damage across northern Hillsdale County on April 9th. Isolated damage was reported in other parts of the forecast area as well. Additional details on the entire event will be posted in the coming days.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NORTHERN INDIANA
813 PM EDT TUE APR 14 2015 /713 PM CDT TUE APR 14 2015/

...NWS DAMAGE SURVEY FOR 04/09/15 TORNADO EVENT...
...BRIEF EF0 TORNADO FOUND IN LARGER SWATH OF WIND DAMAGE...

.OVERVIEW...
A SURVEY OF DAMAGE NORTH OF MOSCOW MICHIGAN REVEALED THAT MAINLY
STRAIGHT LINE WINDS CAUSED DAMAGE TO SEVERAL AREAS OF TREES AS
WELL AS SOME STRUCTURES. HOWEVER...FURTHER INVESTIGATION OF RADAR
DATA AND GROUND REPORTS REVEALED A BRIEF TORNADO TOUCHDOWN WITHIN
THE SWATH OF DAMAGE.

WE WISH TO THANK HILLSDALE COUNTY EMERGENCY MANAGEMENT AS WELL AS
LOCAL RESIDENTS FOR THEIR ASSISTANCE WITH THE SURVEY.

RATING:                                EF-0
ESTIMATED PEAK WIND:    85 MPH
PATH LENGTH /STATUTE/:  0.6 MILES
PATH WIDTH /MAXIMUM/:   70 YARDS
FATALITIES:                          0
INJURIES:                             0

START DATE:                        APR 9 2015
START TIME:                         622 PM EDT
START LOCATION:               1 NNE MOSCOW MI
START LAT/LON:                  42.0634/-84.4987

END DATE:                           APR 9 2015
END TIME:                            624 PM EDT
END LOCATION:                  2 NE MOSCOW MI
END LAT/LON:                     42.0669/-84.4879

SURVEY SUMMARY: A WEAKLY ORGANIZED TORNADO TOUCHED DOWN IN AN OPEN
FIELD SOUTHWEST OF THE INTERSECTION OF BIBBINS AND MOSHERVILLE
ROADS. AFTER CROSSING BIBBINS ROAD THE TORNADO APPEARED TO
INTENSIFY SOMEWHAT, UPROOTING AND BREAKING SEVERAL TREES ALONG
MOSHERVILLE ROAD...EAST OF BIBBINS ROAD. THE TORNADO PASSED TO THE
NORTHWEST OF A UNOCCUPIED 2 STORY HOME CAUSING MAINLY TREE AND
WINDOW DAMAGE. 2 LARGE TREES FELL ONTO THE ROOF OF THE HOME AS THE
TORNADO PASSED. SHORTLY AFTER LEAVING THIS PROPERTY THE TORNADO
APPEARS TO LOSE ITS STRUCTURE AND LIKELY DISSIPATED BEFORE A GROVE
OF TREES TO THE EAST OF THE RESIDENCE.

EF SCALE: THE ENHANCED FUJITA SCALE CLASSIFIES TORNADOES INTO THE
FOLLOWING CATEGORIES.

EF0...WEAK......65 TO 85 MPH
EF1...WEAK......86 TO 110 MPH
EF2...STRONG....111 TO 135 MPH
EF3...STRONG....136 TO 165 MPH
EF4...VIOLENT...166 TO 200 MPH
EF5...VIOLENT...>200 MPH

...NWS DAMAGE SURVEY FOR 04/09/2015 THUNDERSTORM WIND EVENT

...SUMMARY OF DAMAGE NORTH OF MOSCOW MICHIGAN-UPDATE 1...

PEAK WIND /ESTIMATED/:  85 TO 90 MPH
PATH LENGTH /STATUTE/:  2.2 MILES
PATH WIDTH /MAXIMUM/:   300 YARDS
FATALITIES:                         0
INJURIES:                            0

START DATE:                     APR 9 2015
START TIME:                      620 PM EDT
START LOCATION:            0.5 NW MOSCOW
START LAT/LON                42.0574/-84.5150

END DATE:                        APR 9 2015
END TIME:                         625 PM EDT
END LOCATION:               1.8 NE MOSCOW
END LAT/LON                    42.0707/-84.4768

TREES WERE BLOWN DOWN ALONG A SWATH FROM MOSCOW ROAD...
NORTHEAST ACROSS BIBBENS ROAD...TO MOSHERVILLE ROAD. NUMEROUS
TREES WERE IMPACTED ALONG THE SWATH OF WIND...SEVERAL OF WHICH
WERE LIKELY DEAD. THE WINDS DID IMPACT A FARM ALONG MOSHERVILLE
ROAD...PUSHING A LARGE BARN OFF ITS PARTIALLY ELEVATED
FOUNDATION...SEVERELY DAMAGING THE STRUCTURE. OTHER THAN 2 SILOS
LOSING THEIR TOPS...SURROUNDING BUILDINGS SUFFERED FAR LESS
DAMAGE. THE END SEGMENT OF A CENTER PIVOT WAS FLIPPED AND
SEPARATED FROM THE UNIT BEFORE THE WINDS WEAKENED AS THEY CROSSED
ROUND LAKE ROAD. A YOUNG PINE TREE WAS UPROOTED ALONG THE ROAD
WITH A SOUTH FACING GARAGE DOOR SUFFERING MINOR DAMAGE FROM THE
IMPACT OF THE WIND.

NOTE:
THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO
CHANGE PENDING FINAL REVIEW OF THE EVENT AND PUBLICATION IN
NWS STORM DATA.

$$

FISHER