Developing thunderstorms approaching Ann Arbor

A line of developing thunderstorms stretching from Flint south to Saline is moving northeast at 45 mph. One of the stronger cells is expected to arrive in Ann Arbor within 10 minutes. Expect 30+mph wind gusts, 5 minutes of moderate downpour (light rain for much longer), and infrequent lightning.

These storms are not severe right now but will continue strengthening due to the warm moist air throughout the area. They do not represent a severe threat for the city.

KDTX Composite Reflectivity May 31, 2013 12:22pm
KDTX Composite Reflectivity May 31, 2013 12:22pm

Special weather statement issued 12:23pm from NWS Detroit:

WWUS83 KDTX 311623
SPSDTX

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1223 PM EDT FRI MAY 31 2013

MIZ054-055-061-062-068>070-075-076-083-311730-
GENESEE-LAPEER-LIVINGSTON-MACOMB-MONROE-OAKLAND-SANILAC-TUSCOLA-
WASHTENAW-WAYNE-
1223 PM EDT FRI MAY 31 2013

...SPECIAL WEATHER STATEMENT...

AT 1222 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN
AREA OF DEVELOPING THUNDERSTORMS ALONG A LINE EXTENDING FROM FLINT
TO HOWELL TO SALINE...MOVING NORTHEAST AT 45 MPH.

WINDS GREATER THAN 30 MPH...OCCASIONAL CLOUD TO GROUND LIGHTNING...
BRIEF MODERATE DOWNPOURS...ARE POSSIBLE WITH THESE STORMS.

* THUNDERSTORMS WILL BE NEAR...
 WILLIS AND HAMBURG BY 1230 PM EDT...
 FLAT ROCK AND BELLEVILLE BY 1235 PM EDT...
 TRENTON AND ROMULUS BY 1240 PM EDT...
 MILLINGTON AND TAYLOR BY 1245 PM EDT...
 WYANDOTTE AND SALEM BY 1250 PM EDT...
 LIVONIA AND DEARBORN BY 1255 PM EDT...
 DETROIT AND GRAND BLANC BY 100 PM EDT...

GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS TO BLOW
AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK
SHELTER IN A STURDY STRUCTURE UNTIL THESE STORMS HAVE PASSED.

$$

MANN

Moderately strong thunderstorm approaching Ann Arbor

A somewhat strong thunderstorm is expected to reach Ann Arbor around 10:30-10:35 tonight. The storm is not classified as severe; but we can expect 30+ mph wind gusts, heavy rain for ~15 minutes (light rain for much longer), some lightning, and pea-sized hail.

SPC’s outlooks put us at a 5% risk of hail or damaging wind through tomorrow morning.

KDTX Composite Reflectivity 10:13pm May 30, 2013
KDTX Composite Reflectivity 10:13pm May 30, 2013

Special Weather Statement:

WWUS83 KDTX 310211
SPSDTX

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1011 PM EDT THU MAY 30 2013

MIZ068-069-075-076-082-083-310345-
LENAWEE-LIVINGSTON-MONROE-OAKLAND-WASHTENAW-WAYNE-
1011 PM EDT THU MAY 30 2013

...SPECIAL WEATHER STATEMENT...

AT 1008 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 6 MILES NORTHEAST OF TECUMSEH...MOVING NORTHEAST
AT 35 MPH.

PEA SIZE HAIL AND WINDS GREATER THAN 30 MPH ARE POSSIBLE WITH THIS
STORM.

* THE THUNDERSTORM WILL BE NEAR...
 SALINE BY 1020 PM EDT...
 ANN ARBOR BY 1035 PM EDT...
 DIXBORO AND YPSILANTI BY 1040 PM EDT...
 SALEM BY 1055 PM EDT...
 NORTHVILLE BY 1100 PM EDT...
 NOVI BY 1105 PM EDT...
 WEST BLOOMFIELD BY 1120 PM EDT...

GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS TO BLOW
AROUND. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS
PASSED.

$$

DG

Thunderstorms expected across the area this evening; moderate severe potential

This afternoon, mid lower Michigan has seen numerous severe thunderstorms form rapidly across the state. Ann Arbor is included in the very south of an area which may receive a severe thunderstorm watch in the next couple hours.

Thunderstorm activity across southern Michigan is likely to increase over the next few hours due to  a very warm, moist, unstable atmosphere; the main threat from any storms is expected to be strong wind gusts, with isolated tornadoes possible.

Reading: SPC MD 0833

SPC Mesoscale Discussion 0833
SPC Mesoscale Discussion 0833

Update: Worth noting: the thunderstorm outlook effective 8pm-midnight puts us at a 10% risk of thunderstorms; as the night comes and temperatures cool, this threat should diminish rapidly after dark.

Thunderstorm Outlook May 20, 2013 8pm-midnight
Thunderstorm Outlook May 20, 2013 8pm-midnight

Update on thunderstorms moving through SE MI

A line of thunderstorms currently stretching from north of Howell to Dundee is expected to continue strengthening and moving northeast at 30mph.

This line may bring 30+mph winds, small hail, and occasional lightning along with heavy rain. The rain downpour lasted about 10 minutes in Ann Arbor and was quite heavy.

NWS Detroit issued the following special weather statement.

WWUS83 KDTX 301736
SPSDTX

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
136 PM EDT THU MAY 30 2013

MIZ068-069-075-076-301830-
LIVINGSTON-OAKLAND-WASHTENAW-WAYNE-
136 PM EDT THU MAY 30 2013

...SPECIAL WEATHER STATEMENT...

AT 130 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 5 MILES WEST OF ANN ARBOR...MOVING NORTHEAST AT
30 MPH.

PEA SIZE HAIL...WINDS GREATER THAN 30 MPH...OCCASIONAL CLOUD TO
GROUND LIGHTNING...BRIEF HEAVY DOWNPOURS...ARE POSSIBLE WITH THIS
STORM.

* THE THUNDERSTORM WILL BE NEAR...
 ANN ARBOR BY 140 PM EDT...
 DIXBORO BY 145 PM EDT...
 WHITMORE LAKE BY 150 PM EDT...
 SALEM AND SOUTH LYON BY 200 PM EDT...
 NORTHVILLE BY 210 PM EDT...
 NOVI BY 215 PM EDT...
 WEST BLOOMFIELD BY 230 PM EDT...

GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS TO BLOW
AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK
SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED.

$$

SS/MR