URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 476
   NWS STORM PREDICTION CENTER NORMAN OK
   335 PM CDT MON AUG 25 2014

   THE NWS STORM PREDICTION CENTER HAS ISSUED A

   * SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
     NORTHERN ILLINOIS
     NORTHERN AND CENTRAL INDIANA

   * EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 335 PM UNTIL
     1100 PM CDT.

   * PRIMARY THREATS INCLUDE...
     ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
     ISOLATED LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE

   THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 50
   STATUTE MILES EITHER SIDE OF A LINE FROM 35 MILES WEST NORTHWEST
   OF MARSEILLES ILLINOIS TO 35 MILES NORTHEAST OF INDIANAPOLIS
   INDIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
   ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
   FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
   AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
   THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
   AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
   DO PRODUCE TORNADOES.

.    INDIANA COUNTIES INCLUDED ARE

BENTON           BOONE               CARROLL
CASS             CLINTON             FOUNTAIN
FULTON           GRANT               HAMILTON
HANCOCK          HENDRICKS           HOWARD
HUNTINGTON       JASPER              KOSCIUSKO
MADISON          MARION              MARSHALL
MIAMI            MONTGOMERY          NEWTON
PARKE            PULASKI             PUTNAM
STARKE           TIPPECANOE          TIPTON
VERMILLION       WABASH              WARREN
WHITE            WHITLEY

Isolated instances of damaging straight-line winds and some hail are possible this afternoon across northern Illinois, northern Indiana and possibly portions of southern Lower Michigan, according to a “Mesoscale Discussion” that the National Weather Service Storm Prediction Center issued at 2:10 p.m. EDT.

Meteorologists at the time did not anticipate issuing a watch for the area, but they planned to monitor thunderstorm trends this afternoon to determine if a watch will become warranted.

Damage from a flash flood this morning forced the Allen County Highway Department to the close Smith Road between Lower Huntington Road and Yohne Road, just southwest of Fort Wayne. The flash flood washed away soil on the west side of the road, creating a hole approximately 40 feet wide and 25 feet deep. Workers will fill the hole with gravel.

The National Weather Service issued a flash flood warning for the area at 4:17 a.m. EDT. It was in effect until 8:15 a.m.

SKYWARN storm spotter activation might still be needed tonight, according to an updated “Hazardous Weather Outlook” that the northern Indiana National Weather Service office issued at 5:40 p.m. EDT.

The outlook indicated that thunderstorms are likely tonight, with locally heavy rainfall and minor flooding possible. Some storms might be strong to severe along and south of the U.S. 30 corridor, with damaging straight-line winds being the primary threat.

Much of Indiana — including all of IMO SKYWARN quadrant two — continues to have a slight risk of severe weather between 4 p.m. EDT today and 8 a.m. EDT tomorrow, according to an updated “Day 1 Convective Outlook” that the National Weather Service Storm Prediction Center issued at 4:05 p.m. EDT.

The highest probabilities remain at 15 percent for either damaging straight-line thunderstorm winds of 58 mph or greater or large hail of one inch or more in diameter. The 15 percent hail probability, however, no longer includes an Ohio counties.

Factors that are limiting atmospheric instability should mitigate the potential for severe weather this afternoon and early evening, according to an “Area Forecast Discussion” that the northern Indiana office of the National Weather Service issued at 3:10 p.m. EDT. Meteorologists indicated, however, that coverage of showers and non-severe thunderstorms will increase over the next few hours.

I wrote yesterday that the National Weather Service (NWS) Storm Prediction Center (SPC) had issued convective outlooks for the following eight days that indicated no expectation of severe weather in Indiana.

Conditions changed since then.

As of 8:35 a.m. EDT, approximately the northern three fourths of Indiana and large parts of nearby states have a slight risk of severe weather between 9 a.m. EDT today and 8 a.m. EDT tomorrow, according to a “Day 1 Convective Outlook” that the SPC issued.

The entire slight risk area has a 15 percent probability of either of the following types of severe weather within 25 miles of a point:

• Damaging straight-line thunderstorm winds of 58 mph or greater.
• Large hail of one inch or more in diameter.

In addition, a large part of Indiana — primarily in the northwestern and north central regions — have a 2 percent probability of a tornado within 25 miles of a point.

If these probability numbers (15 percent and 2 percent) seem insignificant, have a look at the SPC’s explanation of what they mean.

Any severe weather that does occur is most likely this afternoon and evening. Showers and thunderstorms are forecast in the area this morning, but a second round of storms later today is mostly likely to contain severe weather.

SKYWARN storm spotter activation might be needed this afternoon and evening, according to the “Hazardous Weather Outlook” that the northern Indiana NWS office issued at 4:39 a.m. The slight risk area includes all of IMO SKYWARN quadrants two, three and four and nearly all of quadrant 1, with only the northeastern halves of Hillsdale and Fulton Counties excluded.

Anyone in the slight risk area — especially anyone involved in outdoor activities — should be sure they have a way of knowing about any weather watches or warnings that NWS might issue today.

As always, as time permits, I’ll update this blog with more information as it becomes available. Any updates will appear on the blog’s home page.

Meteorologists do  not expect any severe weather in or near Indiana through Wednesday, August 27, according to convective outlooks issued by the National Weather Service Storm Prediction Center.

Thunderstorms are possible for the next several days and some might be strong, especially Thursday. But meteorologists do not expect widespread severe weather.

Meteorologists indicated a 40 percent probability that they will issue a weather watch for northern Indiana this afternoon, in a “Mesoscale Discussion” the National Weather Service Storm Prediction Center issued at 2:03 p.m. EDT.

The area covered by Mesoscale Discussion 1580 includes all or part of the following counties in IMO SKYWARN quadrant two: Allen (Ind.), Whitley, Huntington, Wells, Adams, Blackford, Paulding and perhaps other nearby counties.