Tomorrow, a full page on TS Bret will come up with all the info you need.
Check back by 10 am tomorrow morning for the page.
Sunday, July 17, 2011
Mesoscale Discussion #1644 (July 17)
AREAS AFFECTED...SERN ND...NERN SD CONCERNING...TORNADO WATCH 652... VALID 172334Z - 180030Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 652 CONTINUES. ISOLATED LONG-LIVED TORNADIC SUPERCELL...LOCATED OVER LAMOURE COUNTY ND...IS PROPAGATING SSEWD AT ROUGHLY 20KT. THIS STORM IS A BIT DEVIANT TO FORECAST STORM MOTION AND BASED ON CURRENT SPEED/MOVEMENT SHOULD SPREAD ACROSS DICKEY COUNTY ND INTO BROWN/MARSHALL COUNTY SD BEFORE 01Z. THIS MAY NECESSITATE A NEW TORNADO WATCH OVER NERN SD AS ENVIRONMENTAL CONDITIONS ARE QUITE UNSTABLE AND MORE THAN ADEQUATELY SHEARED FOR SUPERCELLS/TORNADOES.
July 17: Tornado Warning (Confirmed Tornado)- Oakes, ND
(Weather Centre-Tracked Storm)
THE NATIONAL WEATHER SERVICE IN BISMARCK HAS ISSUED A * TORNADO WARNING FOR... EASTERN DICKEY COUNTY IN SOUTHEAST NORTH DAKOTA... * UNTIL 730 PM CDT * AT 625 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A CONFIRMED TORNADO NEAR BERLIN...OR 43 MILES SOUTH OF JAMESTOWN. DOPPLER RADAR SHOWED THIS TORNADO MOVING SOUTHEAST AT 25 MPH. IN ADDITION...HAIL UP TO BASEBALL SIZE IS LIKELY WITH THIS STORM. VERY HEAVY RAIN WILL FLOOD LOW LYING AND POOR DRAINAGE AREAS. * THE TORNADO WILL BE NEAR... FULLERTON AROUND 645 PM CDT. OAKES AROUND 715 PM CDT. GUELPH AROUND 720 PM CDT. PRECAUTIONARY/PREPAREDNESS ACTIONS... TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER.
Live Updates of July 17 North Dakota Tornadoes
7:21 PM: A wall cloud has been sighted, and a tornado could be lowering soon near Fullerton, ND
July 17: Tornado Warning (Confirmed Tornado)- Oakes, ND
(Weather Centre-Tracked Storm)
THE NATIONAL WEATHER SERVICE IN BISMARCK HAS ISSUED A * TORNADO WARNING FOR... EASTERN DICKEY COUNTY IN SOUTHEAST NORTH DAKOTA... * UNTIL 730 PM CDT * AT 625 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A CONFIRMED TORNADO NEAR BERLIN...OR 43 MILES SOUTH OF JAMESTOWN. DOPPLER RADAR SHOWED THIS TORNADO MOVING SOUTHEAST AT 25 MPH. IN ADDITION...HAIL UP TO BASEBALL SIZE IS LIKELY WITH THIS STORM. VERY HEAVY RAIN WILL FLOOD LOW LYING AND POOR DRAINAGE AREAS. * THE TORNADO WILL BE NEAR... FULLERTON AROUND 645 PM CDT. OAKES AROUND 715 PM CDT. GUELPH AROUND 720 PM CDT. PRECAUTIONARY/PREPAREDNESS ACTIONS... TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER.
StormTrack: July 17: Tornadic Storm in Berlin, ND
The area encircled in blue is showing signs of opposing wind directions, indicating tornadic circulation may be occurring.
Berlin, ND should begin to take cover at this time, as should LaMoure, ND.
July 17: Tropical Depression TWO in the Atlantic
We have little information on this storm at this time.
July 17: Hannaford, North Dakota residents take cover now!
HANNAFORD, NORTH DAKOTA RESIDENTS ARE TO TAKE COVER NOW!
July 17: Tornado Vortex Signature spotted in Courtenay, ND storm
This means that winds in the storm are tornadic. We will continue watching all aspects of this storm and provide updates as needed.
July 17: TORNADO EMERGENCY: Possibly Violent Tornado Occurring near Courtenay, ND
Radar velocities indicate extremely strong winds are in this tornado, and it is likely a tornado is occurring.
We are trying to get visuals at this time.
July 17: Tornado Warning (Radar-Indicated Tornado, Tornado Damage Observed)- Revere, ND
THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A * TORNADO WARNING FOR... NORTHWESTERN BARNES COUNTY IN SOUTHEAST NORTH DAKOTA... SOUTHERN GRIGGS COUNTY IN SOUTHEAST NORTH DAKOTA... * UNTIL 300 PM CDT * AT 218 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A TORNADO. THE DANGEROUS STORM WAS LOCATED 5 MILES WEST OF SUTTON...OR 40 MILES NORTHWEST OF VALLEY CITY. RADAR SHOWED THE TORNADO WAS MOVING TO THE SOUTHEAST AT 25 MPH. AT 108 PM CDT...TORNADO DAMAGE WAS REPORTED 4 MILES SOUTH OF NEW ROCKFORD. * THE TORNADIC STORM WILL BE NEAR... SUTTON AROUND 225 PM CDT. REVERE AROUND 235 PM CDT. WIMBLEDON AROUND 240 PM CDT. HANNAFORD AROUND 250 PM CDT. THEREAFTER SOME OTHER LOCATIONS IMPACTED BY THE TORNADIC STORM INCLUDE WALUM AND ROGERS. PRECAUTIONARY/PREPAREDNESS ACTIONS... IF YOU ARE IN THE PATH OF THIS TORNADO ABANDON CARS AND MOBILE HOMES FOR A STURDY BUILDING. TO REPEAT...A TORNADO HAS BEEN OBSERVED. TAKE COVER NOW.
StormTrack: July 17: Tornadic Storms in Grace City, ND
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| Velocities. Note the couplet of potential tornadic rotation by Grace City, ND |
July 17: Special Weather Warning (East ND, Northwest MN)
A Special Weather Warning has been issued for
Northwest Minnesota
East North Dakota
At 11:45 AM... A Moderate Risk area was issued for the above mentioned areas.
Wind and Hail threats prompted this warning to be issued.
All people in this area are advised to secure all outdoor belongings and make preparations for strong winds and large hail.
A tornado is possible in this situation, so keep a TV/Radio on and have your tornado emergency plan at the ready should the need arise.
This warning will expire at 5:00 PM CDT tonight and may need to be extended.
July 17: Moderate Risk Probabilities
...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON FOR ERN ND AND NW MN... ...THERE IS A SLGT RISK OF SVR TSTMS THROUGH TONIGHT FOR THE NRN PLAINS/UPPER MS VALLEY/UPPER GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT FOR NRN NEW ENGLAND/NY... ...NRN PLAINS/UPPER MS VALLEY THROUGH TONIGHT... A REMNANT CLUSTER OF STORMS FROM EARLY THIS MORNING HAS RECENTLY SHOWN SIGNS OF INTENSIFICATION NEAR MINOT ND. THIS CLUSTER IS ASSOCIATED WITH A SHORTWAVE TROUGH MOVING ACROSS NE MT/NW ND...AROUND THE NW PERIPHERY OF THE CENTRAL PLAINS MIDLEVEL HIGH. AT THE SURFACE...A REMNANT BOUNDARY PERSISTS FROM CENTRAL/ERN ND INTO NRN MN...WHILE A REINFORCING FRONTAL SURGE IS MOVING SEWD INTO NE ND/NW MN IN ASSOCIATION WITH A SEPARATE SHORTWAVE TROUGH APPROACHING NW ONTARIO. VERY RICH MOISTURE /BOUNDARY LAYER DEWPOINTS OF 75-80 F/ IS PRESENT ALONG AND S OF THIS BOUNDARY...WHERE ADDITIONAL DAYTIME HEATING WILL COMBINE WITH STEEP MIDLEVEL LAPSE RATES TO RESULT IN EXTREME INSTABILITY THIS AFTERNOON /MLCAPE OF 5000-6000 J PER KG/ AND A WEAKENING CAP. THE THERMODYNAMIC ENVIRONMENT SUPPORTS INTENSIFICATION OF THE ONGOING STORMS IN ND...WITH THE EXTREME INSTABILITY AND 50+ KT EFFECTIVE BULK SHEAR FAVORABLE FOR EMBEDDED SUPERCELLS WITH VERY LARGE HAIL. UPSCALE GROWTH OF THE CLUSTER APPEARS PROBABLE INTO THE AFTERNOON...WHEN COLD POOL DEVELOPMENT AND FORWARD PROPAGATION ALONG THE SURFACE BOUNDARY COULD LEAD TO BOW ECHO FORMATION WITH AN ATTENDANT RISK FOR WIDESPREAD/SIGNIFICANT WIND DAMAGE. THERE WILL ALSO BE SOME RISK FOR TORNADOES WITH THE MORE DISCRETE SUPERCELLS IN THE CLUSTER BY EARLY AFTERNOON...AS THE BOUNDARY LAYER DESTABILIZES AND THE CONVECTION BECOMES SOLIDLY ROOTED AT THE SURFACE. IF THE SCENARIO EVOLVES AS EXPECTED INTO THE AFTERNOON...THE MDT RISK AREA MAY NEED TO BE EXPANDED FARTHER SE INTO MORE OF MN...AND POSSIBLY EVEN NW WI FOR LATE THIS AFTERNOON/EVENING.
Storm Action Day Declared- July 17
A Storm Action Day has been declared for The areas in the region below.
This comes as that area was outlooked for a Moderate Risk upgrade today.
July 17: Moderate Risk Upgrade
MESOSCALE DISCUSSION 1639 NWS STORM PREDICTION CENTER NORMAN OK 1024 AM CDT SUN JUL 17 2011 AREAS AFFECTED...PARTS OF ERN ND...NW MN CONCERNING...OUTLOOK UPGRADE VALID 171524Z - 171630Z GIVEN THE PRESENCE OF STRONG TO EXTREME POTENTIAL INSTABILITY... AND MODEST TO STRONG DEEP LAYER VERTICAL SHEAR...PROBABILITIES FOR THE EVOLUTION OF AN ORGANIZED SEVERE MESOSCALE CONVECTIVE SYSTEM APPEAR TO BE INCREASING...EITHER FROM ONGOING ACTIVITY OR NEW DEVELOPMENT LATER THIS AFTERNOON. THIS WILL BE REFLECTED IN A CATEGORICAL UPGRADE TO A MODERATE RISK FOR SEVERE STORMS ACROSS PARTS OF EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA IN THE 1630Z OUTLOOK UPDATE.
StormTrack: July 17: Tornadic Thunderstorm near Minot, ND
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| Wind Velocities |
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| Maximum Hail Size |
The Weather Centre has issued a Special Weather Warning for
Sawyer, ND
At 10:24 AM... A thunderstorm with a previous tornado warning and maximum hail size of 3.25 inches was located tracking into Sawyer, North Dakota.
People in this area are advised to prepare for life threatening hail and a potential tornado.
Tornado plans are advised to be put into effect at this time as safety conditions are being compromised.
This warning will expire at 10:45 AM.
2011-2012 Winter Forecast has new maps
Our 2011-2012 Winter Outlook map has been redesigned with new maps that will be useful in the long run.
July 17: Tornado Warning- Near Minot, ND
...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN WARD COUNTY UNTIL 1030 AM CDT... AT 1000 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED 11 MILES EAST OF RICE LAKE...OR 16 MILES SOUTH OF MINOT...MOVING EAST AT 40 MPH. LOCATIONS IMPACTED INCLUDE... SAWYER.
Severe Thunderstorm Watch #650
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
NORTHWEST MINNESOTA
NORTHERN AND EASTERN NORTH DAKOTA
EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 955 AM UNTIL 500
PM CDT.
HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 90 MILES WEST OF
DEVILS LAKE NORTH DAKOTA TO 20 MILES NORTHEAST OF BEMIDJI
MINNESOTA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).
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.
DISCUSSION...A PERSISTENT CLUSTER OF TSTMS NEAR MINOT HAS SHOWN
SIGNS OF INTENSIFICATION IN THE PAST 30 MINUTES. THOUGH CONVECTIVE
INHIBITION STILL REMAINS SUBSTANTIAL FOR SURFACE-BASED PARCELS...THE
DOWNSTREAM ENVIRONMENT IS EXTREMELY UNSTABLE ACROSS ND...AND MLCAPE
WILL LIKELY EXCEED 6000 J/KG WITH ADDITIONAL DAYTIME HEATING BY
EARLY-MID AFTERNOON. MEANWHILE...A WELL-DEFINED SPEED MAX IS
CRESTED THE RIDGE FROM NE MT INTO NW ND...AND ASCENT IN ADVANCE OF
THIS WAVE WILL HELP SUPPORT UPSCALE GROWTH OF THE STORM CLUSTER AS
IT MOVES EWD ALONG A RESIDUAL SURFACE BOUNDARY INTO E/NE ND.
VERTICAL SHEAR AND INSTABILITY WILL SUPPORT BOTH SUPERCELLS AND BOW
ECHOES WITH THE POTENTIAL FOR VERY LARGE HAIL AND DAMAGING GUSTS.
AN ISOLATED TORNADO CANNOT BE RULED OUT...ESPECIALLY BY AFTERNOON AS
THE BOUNDARY LAYER WARMS/DESTABILIZES. OTHERWISE...THE STORMS COULD
GROW UPSCALE INTO A BOWING MCS...WITH THE POTENTIAL FOR MORE
WIDESPREAD AND SIGNIFICANT WIND DAMAGE THIS AFTERNOON.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 650. MEAN STORM
MOTION VECTOR 28035.
StormTrack: July 17: Iowa Single-Cell Storms (Morning)
TERMS TO KNOW
CAPE: A measure of instability. 2000+ values considered unstable.
LI: Lifted Index- another measure of instability. Negative values considered unstable.
EHI: Energy Helicity Index. A measure of tornado potential.
VGP: Vorticity Generation Potential
SRH: Storm Relative Helicity. Detects cyclonic motion in thunderstorm updrafts. Considered dangerous at levels above 200.
Looking at current observations, I am seeing the atmosphere as dangerous. It looks like the Lifted Index (A measure of instability) is down into -10, which is very unstable. That coupled with CAPE values of over 5000, makes the atmosphere very rambunctious. One more concerning thing is something called an EHI. Thunderstorms form when warm air rises vertically. Energy. That's the E in EHI. Helicity is the spinning motion that could occur as this warm air rises, priming the environment for potential tornadoes. That's the H. Put them together and we have the Energy Helicity Index. EHI combines both CAPE and Helicity. SRH values are currently at 250 in North Iowa.
All this information put together indicates a tornado potential. However, there are several roadblocks. Shearing is nonexistent in some parts of North Iowa. That kills tornado potential and basically ends hope for tornadoes. But then again, you never know if these parameters do indicate a tornado could occur.
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