Updraft Category Archive: Radar

Hail pummels parts of southern and central Minnesota

Posted at 6:38 AM on May 3, 2012 by Craig Edwards (1 Comments)
Filed under: Radar, Rainfall, Severe weather, Thunderstorms

The corridor from near New Ulm to Zumbrota was clobbered with hail up to two and a half inches in diameter late Wednesday afternoon. Ouch! And Tuesday's storms brought large hail on a swath from Sauk Centre to near Princeton on the order of two inches in diameter.

Storm reports from NWS Chanhassen. Check out previous versions.

Wednesday's storm reports. Source: NOAA Storm Prediction Center

In a separate overnight storm, Milan, in Chippewa County, reported two inch diameter hail.

More storms at daybreak were producing large hail southeast of Fergus Falls. These storms were racing quickly east toward Brainerd and St. Cloud

Raindrops violently tossed in the updrafts of thunderstorms can accumulate ice layers in the cold air in the middle and upper layers of the atmosphere. Tops of the thunderstorms on Wednesday afternoon were above 40,000 feet in southern Minnesota. Commercial aircraft top out at that level for their cruising altitude.

This graphic from Weatherunderground depicts the accumulated precipitation beginning May 2nd and ending at 630 a.m. CDT. Note the track of severe storms in the brighter yellow and orange. These storms produced heavy rainfall as well as large hail. Two and a half inches of rain fell in a short time yesterday afternoon eight miles northwest of New Ulm. Nearly two inches of rain was measured at Zumbrota.

Source:Weatherunderground.com

Lighter rainfall occurred in the Minnesota Arrowhead region in the past 24 hours.

The Minnesota State Climate Office released the hydrological update yesterday. You can read the entire report here.

Recent moisture has helped put a dent in the drought, but there are still areas that need moisture to recover from the seven-month deficit. From the report:

April 2012 precipitation totals were above normal in portions of west central, north central, and northeast Minnesota. Elsewhere, monthly precipitation totals were near the historical average. It was only the second month since July 2011 where monthly precipitation totals were near to above average.

Periods of showers and thunderstorms are in the weather picture through the weekend. Here's the potential rainfall for the next three days.

Source: NOAA NCEP

--Craig Edwards

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Excessive rains possible, preview was Saturday evening

Posted at 6:37 AM on June 20, 2011 by Craig Edwards
Filed under: Radar, Rainfall, Record

Watching the radar from the Target Field weather lab on Saturday evening it was clear the heavy rain was setting up over western Wisconsin. Here's a graphic provided by the Chanhassen National Weather Service of the radar estimated rainfall for the event.

Click on image to enlarge. The small purple pixel represents an estimate of around six inches for the period 7am CDT Saturday to 7am CDT on Sunday

Eau Claire Airport reported 4.74 inches of rain on Saturday evening. LaCrosse measured 4.50 inches. Both of these totals were daily records.

A meteorological summary of the deluge has been posted on the NWS Chanhassen website. See details.

Thankfully we were able to salvage a pretty decent Sunday. This upcoming week, particularly the next three days will be soggy at the least and perhaps downright dangerously wet in some locations.

A very slow moving, spring-like weather system will track through the upper Midwest. The snail pace from west to east will place Minnesota, as well as the eastern Dakotas and western Wisconsin in a prime region for heavy rainfall.

Here's NOAA's Environmental Prediction Center's estimate for rainfall accumulations in the next seventy-two hours.

This graphic gives a general sense of the most likely region for heavy rain. Isolated totals similar to Saturday evening's rain in western Wisconsin are very possible.

Have time to probe beneath the headlines? Here's a great link on the meteorologist's insight on the upcoming heavy rainfall, courtesy of the National Weather Service in Chanhassen.

After enduring this drenching, we can look forward to the prospects of some warmer and drier weather next week. Here's the Climate Prediction Center's temperature outlook for the next eight to fourteen days. Odds favor above normal temperatures.

The Climate Prediction Center's precipitation outlook for the period June 27 to July 3rd, indicates the odds favor less than normal precipitation in our neck of the woods.

By the way the radar is already lit-up in Iowa and far southern Minnesota this morning. The deluge is at hand.
CE

Buffalo Ridge visible on doppler radar

Posted at 8:16 AM on July 12, 2010 by Paul Huttner (3 Comments)
Filed under: Radar, Remote sensing

You know the weather is quiet when we're tracking wind farms on the Buffalo Ridge on doppler radar.

That's the image this morning from the NWS radar at Sioux Falls. You can see the bright yellow line extending from northwest to southeast near Tyler, Minnesota.

Buffalo Ridge visible as bright yellow band northeast of Sioux Falls radar site this morning.

The radar returns are likely wind generation towers on the ridge, and or the ridge itself. The reason you can see the ridge today is that atmospheric conditions are right for superrefraction or ducting, a bending of the radar beam to follow the earth's curvature.

The bending beam hits the high terrain fo the Buffalo Ridge and bounces back to the radar site. Note how the showers in Iowa are moving, but the Buffalo Ridge returns do not.

Rotating turbines from wind farms can cause issues with severe storm detection. NWS has an outreach program to wind energy producers to work on the best placing for wind farms relative to doppler radar sites.

Warm July:

So far July temperatures are running 5.2 degrees above average in the metro. The coolest day before today was 83 degrees on Sunday. Every other day has been at least 85 degrees, with a 92 degree high on the 3rd. This marks the 5th consecutive month of above average temperatures in the metro.

It's interesting to note that while it's been warmer than average, we've only recorded 4 days at or above 90 degrees. The yearly average for MSP is about 13 days, so we're running a little below average when it comes to extreme heat.

Warmest days of the year:

The average high in the Twin Cities hits 84 degrees tomorrow, and will stay there until July 27th. This time period marks the warmest average high of the year in the Twin Cities and other Minnesota locations. Climatologically speaking, we are now moving into the warmest two to four weeks of the year in Minnesota.

Cool start Monday:

Monday morning's cooler low temperatures were the coolest in nearly two weeks in Minnesota. The Twin Cities bottomed out at 61, with 40s in several northeast Minnesota locations.

The push of cooler air also features much drier air with comfortable dew points in the 40s and 50s. Enjoy the free air conditioning and the respite form the heat and humidity!

PH

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