(Update: 11:30 pm. Severe storm warnings in effect for southeastern suburbs of St. Paul for large hail and wind gusts > 60 mph. Doppler radar is estimating 2" diameter hail with some of these cells. The line has temporarily stalled over the southern suburbs, from Eden Prairie and Bloomington to Lakeville, Cottage Grove and Ellsworth, WI - that leads me to believe that some minor flooding is imminent, with Doppler estimates of 2"+ over parts of the south metro. Again, the individual cells are drifting east, but the entire line of heavy/severe storms seems to be lifting slowly north at 5-10 mph - many of us will experience downpours, thunder & lightning, even pea-size hail, but any severe weather will affect a tiny percentage of the area. A slight to moderate risk of severe weather lingers into Thursday, when more watches/warnings are likely.
(Update: 10:30 pm. Doppler shows a line of strong T-storms over the southern suburbs, stretching from Savage east to Lakeville and Cottage Grove. The individual cells within the line are moving east, but the entire line/boundary is lifting slowly northward, and many towns/suburbs will experience downpours, thunder, lightning, even some pea-size hail over the next few hours. The risk of tornadoes has diminished somewhat, but we can't rule out minor wind damage with a few of these cells, along with sudden 1-2" downpours. Flooding of intersections and poor drainage areas is possible. If you live in an area prone to flooding stay alert).
* First (Minnesota) tornado of the year touches down near Nashua (Wilkin county) around 4:40 pm Wednesday afternoon.
* At least 6 separate tornado touchdowns reported Wednesday.
* Large, violent tornado sweeps across Austin, Minnesota. This "multi-vortex" tornado (consisting of several separate tornado funnels are rotating around a common center/wall cloud) caused extensive damage, power outages, flipping cars, closing roads and triggering injuries, especially in the northern suburbs of Austin. We won't know the complete extent of damage until the sun comes up Thursday.
* Same frontal boundary lingers nearby Thursday - another slight/moderate threat of severe storms. I do expect watches/warnings by late afternoon.
* Computer models print out 1-2" of rain for many communities by Friday.
Update: 9:20 pm. Series of Doppler radar images showing severe rotation west of Stewartville. The image below shows a reflectivity display. Note the extreme wind shear causing the tornadic cell to "tilt" over to one side, to the right of the general motion of upper level winds (west/northwest or 290 degrees).
Tornado watch for much of southern MN (does NOT include Twin Cities) until 1 am Thursday morning. At least 6 tornado touchdowns in Minnesota (as of 9:00 pm). The most notable: large, violent tornado hits the Austin area with reports of damage & injuries, possibly a "multi-vortex" tornado with multiple funnels rotating around a common center/wall cloud. The lingering threat is greatest east of Owatonna and Austin, toward Stewartville, Rochester, Cannon Falls and the Winona area. Residents of far southeastern MN should stay alert and stay tuned for possible warnings.
(Click on the image to bring it full screen and read the tornado warning text for the Owatonna area).
Update: 9:00 pm. Reports of a large, damaging tornado in the Austin area, and the threat is not over yet. Cars have been flipped over in the Austin area with injury reports and considerable debris. Power is out throughout the city. A "multivortex" tornado (several tornadoes all spinning around a common center) was observed with this supercell thunderstorm. Tornadoes often form in "families", one tornado touches down, matures and then dies out. Minutes later the same parent thunderstorm spawns a second tornado farther south/east, in the warm, humid air, unaffected by rain/hail-cooled air. This process can continue for many hours, resulting in multiple tornadoes from the same supercell thunderstorm.Update: 8:30 pm. Funnel clouds spotted near Waseca.
* Greatest tornado risk: Austin area. Large tornado on the ground, impacting northern/eastern suburbs of Austin area!
* Tornado warnings posted for southeastern MN counties through the evening hours.
* Greatest risk near Owatonna, Faribault, Austin and Rochester/Stewartville area.
* Strong/severe storms may move into the Twin Cities metro area later tonight - conditions ripe.
* Computer models print out some 1-2" rainfall amounts over the next few days, potential for tropical dew points.
* First Minnesota tornado of the year touches down in Wilkin county (far west central MN) around 4:40 pm. No reports of injuries/damage.
8:34 pm (Greatest threat appears to be just east/northeast of Austin, tornadic supercell moving toward Elkton and Dexter area).
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
817 PM CDT WED JUN 17 2009
MNC099-180215-
/O.CON.KARX.TO.W.0009.000000T0000Z-090618T0215Z/
MOWER MN-
817 PM CDT WED JUN 17 2009
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 915 PM CDT FOR MOWER
COUNTY...
AT 814 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR AND STORM
SPOTTERS WERE TRACKING A LARGE AND EXTREMELY DANGEROUS TORNADO. THIS
TORNADO WAS LOCATED NEAR I 90 EXIT 181...OR NEAR AUSTIN...MOVING
SOUTHEAST AT 35 MPH. IT APPEARS THIS TORNADO WILL TRACK ACROSS THE
NORTH AND NORTHEAST SIDE OF AUSTIN.
IF YOU ARE IN THE PATH OF THIS STORM...YOU MUST GET INDOORS AND
UNDERGROUND IN A BASEMENT. DO NOT STOP UNDER HIGHWAY
OVERPASSES...SEEK SHELTER IN A BUILDING OFF THE HIGHWAY.
* THE TORNADO WILL BE NEAR...
I 90 EXIT 183 AND RENOVA AROUND 820 PM...
ROSE CREEK AND I 90 EXIT 187 AROUND 825 PM...
ADAMS AROUND 835 PM...
GRAND MEADOW AROUND 840 PM...
HIGHWAYS 63 AND 16 AROUND 850 PM...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
CARS AND MOBILE HOMES SHOULD BE ABANDONED FOR A STURDY BUILDING. AS A
LAST RESORT...LAY FLAT IN A DITCH AND COVER YOUR HEAD.
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
817 PM CDT WED JUN 17 2009
MNC131-147-161-180130-
/O.CON.KMPX.TO.W.0008.000000T0000Z-090618T0130Z/
RICE MN-WASECA MN-STEELE MN-
817 PM CDT WED JUN 17 2009
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM CDT FOR NORTHERN
STEELE...NORTHEASTERN WASECA AND EXTREME SOUTHWESTERN RICE
COUNTIES...
AT 815 PM CDT...A FUNNEL CLOUD WAS REPORTED NORTHEAST OF WASECA.
AT 816 PM CDT... THE TORNADIC SEVERE THUNDERSTORM WAS LOCATED 5 MILES
EAST OF WASECA...OR ABOUT 6 MILES SOUTH OF DEERFIELD...AND MOVING
EAST AT 20 MPH.
THE TORNADO WILL BE NEAR...
OWATONNA BY 830 PM CDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.
THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
716 PM CDT WED JUN 17 2009
THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A
* TORNADO WARNING FOR...
SOUTHERN STEELE COUNTY IN SOUTH CENTRAL MINNESOTA...
NORTHEASTERN FREEBORN COUNTY IN SOUTH CENTRAL MINNESOTA...
* UNTIL 800 PM CDT
* AT 715 PM CDT...RADAR INDICATED A DEVELOPING TORNADO. THE MOST
DANGEROUS PART OF THE STORM WAS 4 MILES SOUTHEAST OF STEELE
CENTER...AND MOVING EAST AT 15 MPH.
* LOCATIONS IN THE WARNING INCLUDE...
BIXBY...
BLOOMING PRAIRIE...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
WHEN A TORNADO WARNING IS ISSUED BASED ON RADAR...IT MEANS THAT
STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY ALREADY
BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY.
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
716 PM CDT WED JUN 17 2009
THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A
* TORNADO WARNING FOR...
SOUTHERN STEELE COUNTY IN SOUTH CENTRAL MINNESOTA...
NORTHEASTERN FREEBORN COUNTY IN SOUTH CENTRAL MINNESOTA...
* UNTIL 800 PM CDT
* AT 715 PM CDT...RADAR INDICATED A DEVELOPING TORNADO. THE MOST
DANGEROUS PART OF THE STORM WAS 4 MILES SOUTHEAST OF STEELE
CENTER...AND MOVING EAST AT 15 MPH.
* LOCATIONS IN THE WARNING INCLUDE...
BIXBY...
BLOOMING PRAIRIE...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
WHEN A TORNADO WARNING IS ISSUED BASED ON RADAR...IT MEANS THAT
STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY ALREADY
BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY.
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
637 PM CDT WED JUN 17 2009
THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A
* TORNADO WARNING FOR...
SOUTHEASTERN WASECA COUNTY IN SOUTH CENTRAL MINNESOTA...
SOUTHERN STEELE COUNTY IN SOUTH CENTRAL MINNESOTA...
EXTREME NORTHEASTERN FARIBAULT COUNTY IN SOUTH CENTRAL MINNESOTA...
FREEBORN COUNTY IN SOUTH CENTRAL MINNESOTA...
* UNTIL 715 PM CDT
* AT 635 PM CDT...RADAR INDICATED A DEVELOPING TORNADO. THE MOST
DANGEROUS PART OF THE STORM WAS 4 MILES NORTHWEST OF HARTLAND...OR
ABOUT 4 MILES NORTH OF FREEBORN...AND MOVING NORTHEAST AT 10 MPH.
* LOCATIONS IN THE WARNING INCLUDE...
MANCHESTER...
HARTLAND...
ALBERT LEA...
NEW RICHLAND...
STEELE CENTER...
BIXBY...
HOLLANDALE...
HAYWARD...
GENEVA...
ELLENDALE...
CLARKS GROVE...
BLOOMING PRAIRIE...
* First Minnesota tornado of 2009 reported near Nashua (Wilkin County in far west central MN) at 4:40 pm. No reports of damage/injury.
** Atmosphere over central/southern Minnesota remains ripe for strong/severe T-storms into the nighttime hours, heaviest storms may come after sunset.
*** 81 degree dew point at St. James earlier: heat index: 106!
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
637 PM CDT WED JUN 17 2009
THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A
* TORNADO WARNING FOR...
SOUTHEASTERN WASECA COUNTY IN SOUTH CENTRAL MINNESOTA...
SOUTHERN STEELE COUNTY IN SOUTH CENTRAL MINNESOTA...
EXTREME NORTHEASTERN FARIBAULT COUNTY IN SOUTH CENTRAL MINNESOTA...
FREEBORN COUNTY IN SOUTH CENTRAL MINNESOTA...
* UNTIL 715 PM CDT
* AT 635 PM CDT...RADAR INDICATED A DEVELOPING TORNADO. THE MOST
DANGEROUS PART OF THE STORM WAS 4 MILES NORTHWEST OF HARTLAND...OR
ABOUT 4 MILES NORTH OF FREEBORN...AND MOVING NORTHEAST AT 10 MPH.
* LOCATIONS IN THE WARNING INCLUDE...
MANCHESTER...
HARTLAND...
ALBERT LEA...
NEW RICHLAND...
STEELE CENTER...
BIXBY...
HOLLANDALE...
HAYWARD...
GENEVA...
ELLENDALE...
CLARKS GROVE...
BLOOMING PRAIRIE...
(Update: 5:05 pm. A tornado warning is posted for Grant, Otter Tail and Wilkin counties until 5:45 pm. People living in the Elbow Lake area are potentially in the path of this tornadic storm, which is producing 3/4 to 1"+ hail. As a rule the larger the hail the greater the potential for the same violent updraft spawning a tornado. The threat of severe weather will continue, spreading from west central into central Minnesota later this evening. Computer models suggest that storms will become even more widespread during the evening and early nighttime hours, spreading from west/north toward the east/southeast, reaching St. Cloud after 8 or 9 pm, into the Twin Cities by 11 pm or midnight. Most of us will NOT see anything severe, but isolated reports of damaging hail, straight-line winds over 70 mph, and an isolated tornado [first of the year in Minnesota] can't be ruled out).
(Latest Supercell Composite Index from SPC, the Storm Prediction Center. The greatest risk of severe "supercell" thunderstorms is over far southwestern MN and much of central and western Iowa this afternoon. With murky sun, a very unstable airmass, and sufficient wind shear aloft conditions seem ripe for strong/severe T-storms. A tiny percentage may produce large, damaging hail, damaging straight-line winds, even an isolated tornado. The greatest threat of violent weather appears to be south/west of the Minnesota River, including Albert Lea, Mankato, Worthington, Jackson and Windom later today. Although the greatest risk appears to be across southern Minnesota, a few strong to severe storms may form over central Minnesota, from St. Cloud to the Twin Cities area - the best chance of severe weather coming from 4 to 7 pm. Stay alert, and check in often for possible warnings later today. It's entirely possible that Minnesota will see it's FIRST tornado touchdown of the year later today).
(Midday visible satellite image showing some hazy, murky sun breaking through over much of southwestern Minnesota. This is important, because any heating of the ground and the air immediately above the ground will increase the instability of the airmass over the southern third of Minnesota, increasing the potential for severe storms later today).
(Probability of a tornado touchdown within 25 miles of any point - a 5% risk for much of southwestern and central Minnesota. Many of the ingredients for isolated tornado-producing, supercellular thunderstorms are present. I do expect watches and warnings across parts of central and southern Minnesota later today. Stay tuned).Tuesday night's "slow soaker" - more rain on the way this week
Radar (Tuesday PM) from the National Weather Service in Chanhassen, MN shows a large swath of moderate rainfall over the entire Twin Cities metro. As of 4pm Tuesday, the Twin Cities was around 1.00" behind normal precipitation since June 1st and a little over 5.00" behind normal precipitation since January 1st. More rain is expected this week with, perhaps, our first shot at severe storms statewide on Thursday afternoon/evening.
This is the severe thunderstorm outlook for Thursday/Thursday evening. The Storm Prediction Center has Minnesota and Wisconsin under a slight risk of severe weather.Weather Headlines
* Damp start. Break in the showery pattern Wednesday midday into Thursday afternoon.
* Next chance of organized showers comes late Thursday into Friday. Some storms may be strong to severe. The Storm Prediction Center has MN and WI under a slight risk of severe weather.
* Saturday rain may linger over Wisconsin, clouds and showers can't be ruled out over far eastern Minnesota. Overall, the weekend is looking drier and warm
*Sunday (Father's Day) showers and storm return late
* Long-range guidance: highs mostly in the 80s the last full week of June. No more cold fronts in sight.
Todd's Outlook
Today: damp start, then becoming partly sunny with an unsettled afternoon sky. High: 81
Tonight: Another round of showers and storms slides into western Minnesota. Low: 61
Thursday: Partly sunny. Showers and storms developing late in the day, some strong to severe. High: 81
Friday: Unsettled with a few widely scattered showers or storms. High: 77
Saturday: Drying out. Sunshine returns with June-like temperatures. High: 84
Sunday: Sunny start, clouds increase late with showers and storms by evening. High: 84
Monday: Partly sunny with a chance of scattered showers and storms. High: 85
Tuesday: Still unsettled, getting warm and muggy. High: 87
No comments:
Post a Comment