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Storm Moving through the South; Pacific Storm to Impact the West this Weekend

A storm is expected to develop over the southern High Plains today and track to the Mid-Atlantic through Friday with showers and thunderstorms. On the northern edge, snow, ice, and/or a wintry mix is possible over the central Plains. A significant storm is expected to arrive late Friday through the weekend with rain, heavy mountain snow, and gusty winds for much of the West. Read More >

High Winds and Cold Temperatures Blast into Region

 The National Weather Service office in Northern Indiana (KIWX) accurately predicted the potent cold front and damaging winds that raced across northern Indiana, southwest lower Michigan, and northwest Ohio on the afternoon of March 9th, 2002. Very strong winds in excess of 50 mph caused widespread damage that consisted of uprooted trees, downed power lines and power outages, and significant damage to numerous buildings. 

The KIWX Zone Forecast from Thursday, March 7th, indicated windy conditions and falling temperatures for Saturday March 9th. A Hazardous Weather Outlook was issued at 500 AM EST Friday March 8th, indicating the potential for very windy conditions. A High Wind Watch was issued at 330 pm Friday March 8th, well over 18 hours before the damaging winds began. A High Wind Warning and a very detailed Zone Forecast was issued before 400 AM EST on Saturday March 9th, nearly 9 hours before the damaging winds entered our area! Why was this such an intense cold front with such powerful winds?

Low pressure formed over the Rocky Mountains on Friday morning, March 8th. With bitter cold arctic air in place over the Northern plains and warm moist air over much of the eastern half of the United States, this low developed very rapidly. The low moved to the Texas and Oklahoma Panhandle region by Friday evening, then quickly moved northeast across Kansas and Iowa, to near the Upper Peninsula of Michigan by Saturday afternoon. Meanwhile, a cold front stretching south from the low raced across the Southern Plains Friday night and Saturday morning, then through the Great Lakes and Ohio Valley on Saturday.

The contrast in temperatures over the central part of the nation fueled this storm. Temperatures behind the cold front were in the single digits and teens across the Northern Plains, while temperatures ahead of the cold front were in the 60s and 70s. With this huge difference in temperatures, strong winds developed ahead and along the cold front. Strong southerly winds up to 70 and 80 mph occurred just a few thousand feet above the earth�s surface over the IWX County Warning Area. Along the cold front, showers and a few thunderstorms formed, bringing the stronger winds down to the surface, causing widespread wind damage over Northern Indiana, Extreme Southern Lower Michigan, and Northwest Ohio.

At 11:15 am EST (1515 UTC), the cold front was located across eastern Illinois and rapidly racing east. This satellite image from 1515 UTC is overlayed with surface observations in green, and 3 hour pressure tendencies in yellow (change in surface pressure during a 3 hour period). The surface observations show wind direction and speed (gusts are indicated at the end of the arrow, speeds are in knots, and temperatures are in the upper left corner of each station plot). 

Notice how the winds in Illinois are out of the west and the winds in Indiana are out of the south at 1515 UTC. The 3 hour pressure falls for this event were tremendous. Notice the dashed yellow lines across Indiana, indicating falling pressure of almost 4 millibars per 3 hours. Behind the front, the solid yellow lines indicate pressure rises of almost 11 millibars per 3 hours. This strong "pressure gradient" helped strengthen the winds at the surface. At the bottom of the page are images from every hour during the afternoon of March 9th. Watch the winds, temperatures and pressure changes as the system moves east across the KIWX County Warning Area. Feel free to drop us a note with any questions. 

Due to the advance notice of the expected storm system, emergency managers, law enforcement officials, trained weather spotters, and the general public were all well prepared. As a result, very few injuries were reported across the area. Planning and appropriate actions do make a difference!

NWS AWIPS Images from March 9th, 2002

1515 UTC 1615 UTC 1715 UTC 1815 UTC 1915 UTC 2015 UTC 2115 UTC