The northern Indiana office of the National Weather Service expects isolated thunderstorm development ahead of an approaching cold front, according to an email message the office sent to SKYWARN storm spotters and others this morning. “We expect that the severe threat will be ISOLATED and SHORT LIVED,” the email reads.

The message also provides the following timing and impact information:

Timing

• Through 3 p.m. EDT: Isolated showers and thunderstorms with gusts greater than 30 mph and lightning.
• 3 p.m. to 6 p.m. EDT: More organized lines of thunderstorms with isolated severe thunderstorm potential.
•  6 p.m. to 9 p.m. EDT: Threat of thunderstorms shifts south and east across the region with best organization and threat southeast of a line from Monticello, Indiana to Hillsdale, Michigan.

Impacts

Numerous fairs/festivals and football games will be going on during this time frame. All venues should be making plans for thunderstorm development, monitor NWS Web pages and have NOAA Weather Radio programmed and operational.

See an update to this story.

All of northeastern Indiana has a slight risk of severe thunderstorms between 9 a.m. EDT today and 8 a.m. EDT tomorrow, according to the “Day 1 Convective Outlook” that the National Weather Service (NWS) Storm Prediction Center (SPC) issued at 8:46 a.m. EDT. The slight risk area also includes parts of northwestern Ohio, southern Lower Michigan, Illinois and Missouri. It includes all of IMO SKYWARN quadrants one, two and three and the southeastern half of quadrant four.

The primary threats in the slight risk area are damaging straight-line thunderstorm winds of 58 mph or greater and large hail of one inch or more in diameter. The tornado threat today is negligible (less than a 2 percent probability), according to the SPC.

Storms are most likely in the afternoon and evening. The risk of severe weather will decline rapidly after 11 p.m. EDT.

SKYWARN storm spotter activation might be needed this afternoon and tonight, according to the “Hazardous Weather Outlook” that the northern Indiana NWS office issued at 5:21 a.m.

The SPC will update its severe weather outlook for today by 12:30 p.m. EDT.

Much of Indiana continues to have a marginal risk of severe weather tomorrow afternoon and evening, according to an updated “Day 2 Convective Outlook” that the National Weather Service Storm Prediction Center (SPC) issued at 1:20 p.m. EDT.

The probability of severe weather (5 percent) continued to fall below the SPC’s “slight risk” criteria. As you can see on the map above, the SPC adjusted that 5 percent area so that it no longer includes southern Indiana.

Our next look at the severe weather outlook for tomorrow comes when the SPC issues its first “Day 1 Convective Outlook” of the day tomorrow. It’s due out by 2 a.m. EDT.

Meteorologists expect scattered thunderstorms in northern Indiana, southern Lower Michigan and northwestern Ohio tomorrow afternoon into tomorrow night, according to a “Hazardous Weather Outlook” that the northern Indiana National Weather Service (NWS) office issued at 4:43 a.m. EDT.  There is a low risk that some of those storms could be strong, with isolated wind gusts in excess of 50 mph. Locally heavy rain will also be possible.

The NWS storm prediction center gave the area a 5 percent probability of severe storms within 25 miles of a point, according to the “Day 2 Convective Outlook” that the SPC issued at 12:26 a.m. EDT. Five percent is below SPC’s “slight risk” criteria, but the SPC indicated that if higher probabilities are needed in future outlooks, “it would seem to be areas of lower Michigan into perhaps northern Indiana or northwestern Ohio.”

The next outlook for tomorrow will be an updated SPC day two outlook, due out by 1:30 p.m. EDT.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORTHERN INDIANA
501 AM EDT WED SEP 3 2014

INZ003>009-012>018-020-022>027-032>034-MIZ077>081-OHZ001-002-004-
005-015-016-024-025-031230-
LA PORTE-ST. JOSEPH IN-ELKHART-LAGRANGE-STEUBEN-NOBLE-DE KALB-
STARKE-PULASKI-MARSHALL-FULTON IN-KOSCIUSKO-WHITLEY-ALLEN IN-
WHITE-CASS IN-MIAMI-WABASH-HUNTINGTON-WELLS-ADAMS-GRANT-BLACKFORD-
JAY-BERRIEN-CASS MI-ST. JOSEPH MI-BRANCH-HILLSDALE-WILLIAMS-
FULTON OH-DEFIANCE-HENRY-PAULDING-PUTNAM-VAN WERT-ALLEN OH-
INCLUDING THE CITIES OF...MICHIGAN CITY...LA PORTE...SOUTH BEND...
MISHAWAKA...NEW CARLISLE...WALKERTON...ELKHART...GOSHEN...
NAPPANEE...LAGRANGE...TOPEKA...SHIPSHEWANA...ANGOLA...FREMONT...
KENDALLVILLE...LIGONIER...ALBION...AUBURN...GARRETT...KNOX...
NORTH JUDSON...BASS LAKE...WINAMAC...FRANCESVILLE...MEDARYVILLE...
PLYMOUTH...BREMEN...CULVER...ROCHESTER...AKRON...WARSAW...
WINONA LAKE...SYRACUSE...MENTONE...COLUMBIA CITY...TRI-LAKES...
SOUTH WHITLEY...FORT WAYNE...NEW HAVEN...MONTICELLO...BROOKSTON...
MONON...LOGANSPORT...ROYAL CENTER...PERU...GRISSOM AFB...MEXICO...
WABASH...NORTH MANCHESTER...HUNTINGTON...ROANOKE...BLUFFTON...
OSSIAN...DECATUR...BERNE...MARION...GAS CITY...UPLAND...
HARTFORD CITY...MONTPELIER...PORTLAND...DUNKIRK...NILES...
BENTON HARBOR...ST. JOSEPH...BUCHANAN...DOWAGIAC...CASSOPOLIS...
MARCELLUS...STURGIS...THREE RIVERS...WHITE PIGEON...MENDON...
COLDWATER...BRONSON...HILLSDALE...LITCHFIELD...JONESVILLE...
BRYAN...WAUSEON...ARCHBOLD...FAYETTE...SWANTON...DEFIANCE...
SHERWOOD...HICKSVILLE...NAPOLEON...DESHLER...LIBERTY CENTER...
PAULDING...ANTWERP...MELROSE...OTTAWA...PANDORA...KALIDA...
FORT JENNINGS...VAN WERT...DELPHOS...OHIO CITY...LIMA...
SPENCERVILLE
501 AM EDT WED SEP 3 2014 /401 AM CDT WED SEP 3 2014/

...AREAS OF FOG EARLY THIS MORNING...

FOG WILL REDUCE VISIBILITIES TO BETWEEN ONE AND THREE MILES AT
TIMES THIS MORNING UNTIL SHORTLY AFTER SUNRISE. PATCHY DENSE FOG
IS ALSO POSSIBLE WITH LOCAL VISIBILITIES DROPPING TO BETWEEN ONE
QUARTER AND ONE HALF MILE...ESPECIALLY IN LOW LYING AREAS AND NEAR
BODIES OF WATER. USE CAUTION THIS MORNING WHILE DRIVING AND BE
AWARE OF CHILDREN AT BUS STOPS...SCHOOL BUSES AND OTHER SLOWED OR
STOPPED TRAFFIC. CONDITIONS WILL IMPROVE QUICKLY AFTER SUNRISE.

View the full statement on the NWS website.

Almost all of Indiana and parts of neighboring states have a slight risk of severe weather between 9 a.m. EDT today and 8 a.m. EDT tomorrow, according to the “Day 1 Convective Outlook” that the National Weather Service (NWS)  Storm Prediction Center issued at 8:52 a.m. EDT.

The primary threats are damaging straight-line thunderstorm winds of 58 mph or greater and large hail of one inch or more in diameter this afternoon and early evening.

With the exception of small parts of Laporte and Berrien Counties, the slight risk area includes all of the 37-county warning area of the northern Indiana NWS office and therefore all of IMO SKYWARN quadrant two.

SKYWARN storm spotter activation might be needed late this afternoon through early tonight, according to the “Hazardous Weather Outlook” that the northern Indiana NWS office issued at 6:05 a.m EDT.

Much of northern Indiana — including all or parts of Whitley, Huntington, Wells and Allen Counties — have a slight risk of severe weather between 8 a.m. EDT Labor Day and 8 a.m. EDT Tuesday, according to the “Day 3 Convective  Outlook that the National Weather Service Storm Prediction Center issued at 3:05 a.m. EDT.

Any severe storms that form could contain damaging straight-line winds or large hail.