Monday, June 14, 2010
Developing storm system threatens showers and thunderstorms Thursday into Friday..
A weak system over North Dakota will circulate cloud and a few showers over southeast MB tonight into Tuesday. Most of the shower activity should stay southeast of Winnipeg, although generally cloudy skies will prevail over the Red River valley. Of greater concern is the expected evolution of a stronger storm system over the western US that threatens to bring more widespread showers and thunderstorms to southern Manitoba by Thursday into Friday. This storm system is expected to move over western North Dakota on Wednesday pushing an increasingly warm and humid airmass over southern MB by Thursday. This will likely trigger scattered thunderstorm activity with locally heavy rain possible. Additional showers and thunderstorms are expected Thursday night into Friday over southern MB with areas of heavy rain likely, especially over western MB into the Interlake regions where local rainfall amounts of 40 to 70 mm are possible. This system will bear close watching as soils are saturated across many areas of southern MB and southern SK, and any additional heavy rain will result in more problems for agricultural and hydrological interests.
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June 14th Southern Manitoba Flood Report
ReplyDelete"Overland flooding and some basement flooding occurred in the Interlake region last week due to heavy downpours. The situation is gradually improving but could become serious if heavy additional rain develops later this week."
More rain is definitely not needed in the Interlake. Drove up Hwy # 8 and back #9 from Wpg Beach just before the rain on Sunday.
Rains late last week where some of the area (Teulon/Gimli) escaped much of the May Monsoon, left the fields adjacent to the SW corner of Lake Winnipeg (Dunnottar) under water.
Given positioning of the warm front in the current GFS extended, the may be setting up to be very susceptible for training nocturnal thunderstorms just north of the warm front. If this is the case, I could easily imagine local rainfall amounts of 150mm+ given the amount of precipitable water in the airmass.
ReplyDeleteIf there's clearing and CAPE built up, as per the 15/12Z NAM, I wouldn't be surprised to see a couple of tornadoes on the MB/ND border. Then later likely a fast-moving squall line isn't out of the question. We'll be elsewhere (check my blog to see where, hee hee) but that's our secondary target.
ReplyDeleteModels continue to indicate heavy rain potential with Thursday's system, but concensus remains low on location and amounts. 12z GEM shows an 84 mm QPF bullseye over Regina Thursday morning. GLB much more conservative with a 33 mm bullseye over the Nipawin area. NAM has a 100 mm bullseye along the ND/SD border and an 80 mm bullseye over SW SK around Swift Current. Bottom line.. there will likely be thunderstorms giving heavy rain someplace between South Dakota and central SK Wednesday night into Thursday morning.. but still too early for any greater certainty. Looking at the pattern, I would think southcentral and southeast SK would be the prime target areas for the heaviest rain, but it all depends on how this low level jet and warm front ultimately set up.
ReplyDeleteA bit better convergence seen in GEM, NAM and GFS regarding at least general idea for Thursday. Main threat for severe, surface based storms will likely remain south of Winnipeg. Occluding warm sector does not move north of border until evening.
ReplyDeleteElevated convection should be focused south and west of us Wedensday into Thursday morning. However during the day potential is there for convection to train along warm front as noted and give heavy precip especially to northern RRV and interlake. GFS was very slow catch on to this idea and NAM still not buying into it. Will also have to watch carefully as best low level shear (30-40 kts) will occur vicinty of warm front with SE flow.
Warm front lifts as evening progresses and attention turns to surface trough slicing thru eastern N Dakota. Atmoshphere will initially be capped so convective initation would not occur until late. Lots of instability and deep shear to work with. If cap does break, cells will likely have tendancy to organize into forward propogating derecho as mentioned given speed/strength of dry push behind trough. I would not be surprised to see it split.... a forward propogating segemnt racing off to the ENE and another building down into LLJ where the better moisture resides. In any event Winnipeg may get another round of strong tstorms in the early morning hours of Friday before dry slot wraps in.
Some slow moving to almost stationary cells have developed just south and east of Winnipeg this afternoon from Beausejour through Lorette down to Morris. Looks like they have about 30-40 minute lifespans and are giving some localized downpours at times.
ReplyDeleteWow, just started pouring, and temperature went from 26 to 22 on my thermometer in just a matter of minutes!
ReplyDeleteAre Those cells north of the city moving up Hwy 8 to Teulon??
ReplyDeleteWow that was a lot of rain in a short time just North of the perimeter. Oh well at least it will keep the dust down. Oh yeah no dust till August.
ReplyDeleteI have a feeling residents in Southern Manitoba will be digging out there scuba gear pretty soon if this heavy rain keeps up!!!
ReplyDeleteA minimum of 60mm. over SE to a max of 160mm. in SW Saskatchewan in the next 72 hr!? ..Winnipeg 40-45mm. See Days 1-3 QPF
ReplyDeleteDo I have time to finish the Agassiz Ark?
Quite the event possible tomorrow.
ReplyDeleteSPC has the 30% hatched are right up against the border, with hints that a moderate risk area may be added tomorrow.
EHI values of 3 to 5 are expected in the RRV and SE MB, along with CAPE of around 2500J/kg according to the NAM.
Yes, a very active 24-36 hours ahead. Tonight will be interesting to see where elevated convection erupts north of the warm front over the Dakotas.. Best bet is over central and western ND along nose of strengthening LLJ as it rides over warm front, with plenty of low level moisture to tap over the central Plains (20C dewpoints pushing into SD now) Good potential for some severe storms with hail overnight, as well as very heavy rain producers especially if east-west band of training cells develops ahead/along warm front as often happens in these cases. Highest threat area for this activity would be pushing into SW MB and SE SK overnight into Thursday morning, although activity may spill eastward into the RRV Thursday morning as warm front pushes north.
ReplyDeleteHeavy rain will push north and west through Interlake and western MB/southern SK as low winds up over ern MT/western ND pushing sharp cold frontal/dry line into southern MB from a non-traditional south to southwest direction. Strong southerly flow aloft will mean that any storms/supercells that fire up on this boundary would be moving due north, as opposed to the more traditional northeast to east direction. Could be a very muggy afternoon as RRV briefly gets into warm sector with dewpoints climbing into the upper teens to 20C mark before cold front pushes in by late afternoon. Convective development will likely be capped much of the day until cold front pushes in, with narrow band of potentially severe cells late Thursday into Thursday evening across RRV and SE MB. Severe threat will depend on how much surface heating we get in the warm sector to crank up those CAPE values. Strong low level shear with good low level backing of winds will support supercells with large hail likely along with isolated tornadoes with early discrete cells. Note that SPC is considering upgrading to a MDT risk for severe storms over the northern plains for tomorrow. Yes indeed, will be an interesting 24 to 36 hours ahead!
Looks more and more likely that we will see a bimodal distribution in terms of heaviest QPF.
ReplyDelete1)Along nose of LLJ where it intersects warm front as mentioned. This area and associated convection will veer from western N Dakota to RRV by mid to late morning. Only caveat would be weaker frontogenesis (fairly warm north of front).
2)At the same time some of this convection will be pulled NW and another area of precip will blossom at the intersection of developing trowal and upper low over SW Saskatchewan.
We look to stay on the cool cloudy side of the front most of the day with ESE winds. Two areas to watch for severe convective development:
i)if enough clearing can occur in vicinity of warm front... cells would have access to lots of low level shear (30-35 kts),backed SE surface flow, and outflow from elevated convection.
ii)along surface trough/ cold front as it moves up from N Dakota. Convection has to overcome cap and occlusion of best instability as Rob mentioned. Dynamics would seem to favor the rapid evolution of a linear structure if convection initiates. Consequently, there is a brief window for discrete tornadic cells but threat is still there.
Summarizing, there is a potential for two rounds of strong to severe storms...
*threat of elevated convection/ heavy rain along warm front from mid morning to early aft along with some rogue surface based cells having some tornadic potential
**threat of initially discrete, possibly tornadic supercells coalescing into bowing line along cold front with strong straight line winds the main hazard late in the evening.
Ensemble is showing an 80% chance of more than 50mm of rain in western SK. That is among the heaviest rain I have seen the ensemble predict on the prairies.
ReplyDeleteThe EC cloud forecast models are showing good clearing tomorrow morning in the RRV and SE MB. If this is the case, we should see temperatures climb quite well before heavier cloud cover moves in by the afternoon. Of course convective debris and elevated convection lingering from the overnight period will need to be watched.
Tornado watch now issued for parts of North Dakota just as you guys had anticipated!!!
ReplyDeleteAnyone see the potential for damaging winds tomorrow in the Red River Valley ????
EC calls for 40 -70 km/h from the south.
The reason I ask about the winds is because I see North Dakota has a high wind watch for tomorrow!
ReplyDeleteSevere winds gusts expected!!!
Personally, this is the first time I see a weather warning in June! Usually, it seems we get them in the winter.
ReplyDeleteI'm hearing golfing tomorrow afternoon SE of Steinbach could have more hazards than usual.
ReplyDeleteInteresting altocumulus field just passed over Winnipeg hinting at elevated instability well east of where LLJ and moisture advection are progged. Another area of altocumulus over SW Manitoba where may convection may start firing soon.
ReplyDeleteConvection blowing up along LLJ over NC South Dakota and NE Montana. Evolution of MCS remains enigmatic but think current radar returns south of Bismarck will continue slowly spreading NE and eventually affect our region by early morning. Debris cloud will likely limit surface heating until possibly later in the afternoon as warm front lifts north...
We'll have to see how quickly that convective complex from ND moves through. If we can't get sufficient clearing today, the threat for surfaced based activity in Manitoba will be minimal.
ReplyDeleteDue to computer issues, my weather station is not updating at the moment. I hope to get it resolved later today..
ReplyDeleteIn the PASAC discussion this morning they state that a "moist tongue" is from Nebraska into the Dakotas
ReplyDeleteNever heard that term before!
Rob!
ReplyDeleteI see Winnipeg's forecast does not include any rainfall amounts for TODAY!
If that storm complex in North Dakota hits later then 25 mm or so is not out of the question!!!
The term "moist tongue" is actually a commonly used meteorological term when referring to the axis of best moisture. Storm chasers often look for this moist tongue in their target area.
ReplyDeleteLooks like some heavy rain is now heading into Southern Manitoba
ReplyDeleteWinnipeg looks like it could pick up a quick inch of rain!
The SPC has gone moderate risk for today's set up...but I'm not a real fan of the shear profiles in the moderate risk hatched tornado zone. That area actually looks prime for storms that quickly merge into a string of pearls with the odd embedded supercell and bowing segment. I actually like the area N and E of Grand Forks into Southern Manitoba for tornadoes...
ReplyDeleteThe real limiting factor in my favored area is the cloud cover...but if the dry slot can work itself into Manitoba today by 2-3pm, then watch out.
For initiation on a Canadian Chase I'd probably sit myself in Gretna or Altona and hope things clear allowing for the surface to heat up. Speed and Directional Shear is amazing near the Int'l Border...like I mean amazing. Copius amounts of moisture tied with great instability (as progged by latest RUC run) show storms rapidly developing in this area by 4-7pm.
Looks like tornado potential will be from a Gretna - Letellier - Vita line if we can lose the clouds...
If we can't lose the clouds then I'd drift south into North Dakota to find the clearing...
Ahh, I wish I was there.
SPC has stated that they will most likely be issuing a tornado watch for most of North Dakota!
ReplyDeleteLooks like this afternoon could get very active!!!
That Tstorm moving in on Devils lake now looks interesting around 4pm in Altona Winkler area and Winnipeg by late Rush Hour (TWN Radar)
ReplyDeleteThe winds sure have picked up here in Winnipeg with the past hour!!!
ReplyDelete78 km/h winds at the Winnipeg airport at 2:35 pm!!!
ReplyDeleteWow.....80 km/h wind gusts out of nowhere!
ReplyDeleteYa no kidding, Im seeing a lot of twigs and small branches on the ground now.
ReplyDeleteThe day today sure wasn't as nice as expected! Barely 20C.
quite a few thunderstorms starting to erupt in Southern Manitoba now!
ReplyDeleteThe high for today was originally
28 C yesterday....so ya quite the departure!!
If you can't Golf in this mild breeze and want to catch both the US Open (Mike Weir is one off behind the leader) and follow the Weather, NBC channel 6 on MTS cable is updating regularly. Major situation expected momentarily in Fergus Falls..Detroit Lakes and Alexandria just SW of Fargo TWarnings in all 3. 1 Tornado on the ground now in Lee n Douglas County
ReplyDeleteDaniel, that line of 28C appeared at 1pm to be just south of Fargo thru Wapheton and Fergus. Cooled rapidly to the north.
ReplyDeleteFargo Airport is showing 48mm of rain. The only one greater is Morbridge at 54mm.
Severe storms are EXPLODING in north dakota!
ReplyDeleteA dangerous situation is developing with numerous tornado warnings!!
So far Winnipeg has been remarkably lucky in missing all the storms... they have been diverting around the city in a bizarre fashion. it appears as though our luck is about to run out however with this next wave of elveated convection.
ReplyDeleteWe will get a breif (and I mean brief) taste of clearing and warm sector behind this current line. However, surface based convection has erupted along surface trough with at least 10 tornado warnings (!!!) in N Dakota/ NW Minnesota... unreal.
Discrete cells should rapidly merge and produce another large area of heavy rain that will move up in a few hours. Strong straight line winds will also be a threat.
Severe thunderstorm watch issued for SW and south central Manitoba (excluding Winnipeg).
ReplyDeleteThese and other reports are coming in every few minutes on FGF Local Storm Report
ReplyDeletePRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
409 PM CDT THU JUN 17 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0405 PM TORNADO HOLMES 47.72N 97.30W
06/17/2010 GRAND FORKS ND FIRE DEPT/RESCUE
MULTIPLE VORTEX TORNADO
0339 PM TORNADO 8 NNE FINLEY 47.62N 97.77W
06/17/2010 STEELE ND NWS EMPLOYEE
RELAYED BY OFF DUTY DODGE CITY NWS METEORLOGIST CHASING
STORM.
funnel cloud reports as far north as Oslo MN...
ReplyDeleteEC is going to have to extend severe Tstorm watch a bit further east and soon issue warnings. Leading tornadic cell will soon cross into Manitoba with several behind. I doubt they can weaken fast enough to prevent severe parameters from affecting Manitoba.
ReplyDeleteI'm a little surprised by EC not issuing Severe thunderstorm watches at least along the international border (sw part of MB) since the storms coming up from the south are decently strong and even have tornado warnings on them in the US.
ReplyDeleteI am baffled as to why EC has not extended Tstorm watch or issued warnings along intl in SE Manitoba. Cells have a history of producing multiple tornadoes and funnel clouds... along with hail and strong straight line winds. Leading edge of line will cross just east of Emerson at about 6:15. What is the delay?
ReplyDelete@Daniel
ReplyDeleteOn the Grand Forks radar, the storms appear to be weakening for the most part. On the Woodlands radar, the dBZ values aren't even at the 50s (which would be oranges and reds).
Ahhh there we go, finally the watch has been issued. It's just too bad it takes so long... Often takes until the storms are actually already coming through to issue a watch!
ReplyDelete@Connor...
ReplyDeleteDo not go by the unacceptably low resolution Woodlands radar. Mayville radar show cells still capable of producing tornadoes and a tornado warning is even out for areas along Manitoba border.
Remember that a watch is the potential for severe development. There is often some inertia in the weakening of these storms and unstable boundary layer air can advect northwards with these systems. Therefore at least a watch was warranted.
Take a look a Winnipeg's winds today!!!!!
ReplyDeleteStrong from the southeast
then calm
then from the west
then the northeast
now back to the southeast!!!
Can anyone explain what is going on??????
@Daniel (with the Blogger account)
ReplyDeleteTrue, as a storm's strength can vary until it is very apparent (typically after 10:00 PM or so) that the storms are losing strengh.
pffffft. This sure wasn't anything worth waiting for!! =(
ReplyDeleteLooks like south end was forgotten today for thunderstorms.
I see Rob has his weather station back online today!!!
ReplyDeleteWelcome back!
@ Daniel P
ReplyDeletethe syonptic winds were from the SE.. the calm to west winds represent mesoscale effects from convection (outflow etc). Behind the trough our winds will switch to SW...
Have to say that we were very fortunate here in Winnipeg to escape all modes of severe weather. Hard to believe with so much moisture and dynamics some places seem to have barely gotten 5-10 mm of rain. Will be very interesting to see map of radar estimated precip...
Yep, a lot of potential that fizzled out over RRV and SE MB.. with minimal rainfall (thankfully) and precious little in severe thunderstorms. However, it wasn`t too far away.. with 60-80 mm of rain over Killarney-Minot area as well as other spots in North Dakota, as well as tornadic cells just south of the border. In the end, it was a non-event for Winnipeg (other than some brief downburts winds that occurred around the same time I witnessed an airliner abort a landing just as it was approaching YWG this afternoon)
ReplyDeleteJust a note on how lucky we were....as many as 20 ?? to at least EF3??
ReplyDeletePUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE GRAND FORKS ND
907 PM CDT THU JUN 17 2010
...STORM DAMAGE SURVEY TEAMS PLANNED FOR FRIDAY JUNE 18...
IN THE WAKE OF THIS AFTERNOONS DEVASTATING TORNADO OUTBREAK
ACROSS PORTIONS OF EASTERN NORTH DAKOTA AND NORTHWESTERN
MINNESOTA...THE GRAND FORKS NWS WILL BE DEPLOYING DAMAGE SURVEY
TEAMS TO BETTER ASCERTAIN THE SEQUENCE AND MAGNITUDE OF THIS
EVENT.
ONE TEAM WILL VISIT THE HARDEST HIT AREAS OF WEST CENTRAL
MINNESOTA INCLUDING THE WADENA AREA. A SECOND TEAM WILL INSPECT
THE DAMAGES REPORTED IN THE FISHER...CROOKSTON AND MENTOR AREAS
OF NORTHWEST4 MINNESOTA. A THIRD TEAM WILL VISIT THE CENTRAL AND
NORTHERN RED RIVER VALLEY AREAS OF NORTH DAKOTA INCLUDING THE
MAYVILLE AND THOMPSON AREAS.
AT THIS TIME THE EXACT EXTENT OF THE DAMAGE OR THE ENHANCED
FUJITA SCALE OF THE TORNADOES THAT OCCURRED IS UNKNOWN.
PRELIMINARY INDICATIONS SUGGEST THAT SEVERAL OF THE TORNADOES
WERE AT LEAST EF3...POSSIBLY GREATER IN INTENSITY.
ALSO...PRELIMINARY STORM DATA SUGGESTS THAT AS MANY AS 20
TORNADOES MAY HAVE OCCURRED IN THE AFTERNOON AND EVENING HOURS. A
FINAL NUMBER WILL BE AVAILABLE WITHIN A FEW DAYS.
Yeah, cells basically died as far as intensity as they moved north across the border. So much for free trade. So Environment Canada was right in not cranking out warnings. People.. just because storms look severe on radar doesn't equate to these severe storms maintaining themselves moving northward especially moving into more stable, cooler airmass. So don't get over excited in wondering why warnings aren't issued. I would rather have them not cry wolf everytime there is a thunderstorm in the area. Save the watches and warnings for when the situation warrents. Cool, less unstable air ain't no severe weather producer.
ReplyDeleteIt is amazing how the 49th parallel acts as an iron barrier to thunderstorms. You can have a tornado producing storm in Hallock, MN, but the moment it crosses over to Tolstoi, the storm disintegrates.
ReplyDeleteWe'll need to be very mindful of being on the northern side of the warm front in the future. The models have already handled these events poorly twice this spring...back in late May and now in June. The NAM was advertising strong CAPE all the way to Winnipeg yesterday, but the models didn't account for overnight convection (again). Something to remember as we move farther into the season.
Re anonymous:
ReplyDelete"People.. just because storms look severe on radar doesn't equate to these severe storms maintaining themselves moving northward especially moving into more stable, cooler airmass."
Read my earlier comment.. there is a potential inertia involved in the weakening of convection. One also cannot discount the possibility of enough surface based instability *advecting* northwards to sustain severe convection for a short distance. Of course it would not be 100 km or even 10.. but how about 1 km or 500 m? There are several small towns right along the border. Can you really say with any certainty that a supercell will lose all organization exactly as it crosses the border... of course not.
A massive outbreak of at least 20 tornadoes of EF3 or greater intensity was ongoing just across the border (thanks for the link Jim). One would have to be a fool to discount the possibility of severe weather north of the border out of hand. So in my mind a watch was certainly justified. The question of warnings is debatable and dependent on actual evidence that the cells were still severe as they crossed the border (again this is tricky).
Re Scott:
The potential for overnight convection and debris cloud was discussed several times on this thread... it is always an issue when assessing the next day's severe weather risk.
The Iron Curtain myth like many has a thread of fact attached to it. My personal experience colors perceptions of events.
ReplyDeleteOn hundreds of trips on both 59 and I-29/75 dozens of Funnel Clouds spotted approaching the Border several tornadoes reported very few in my experience crossed to the North of the Border...
In Detroit Lakes for the multiple outbreak in the early 70's, in a Minneapolis campground for the 3 day outbreak in the mid 70's and in Mpls for last years August event. Several Fargo outbreaks have been spent in Hotel basements. I followed the Gull Lake Funnels from Inwood and met it at Petersfield (Golf Course) and watched the Pipestone/Elie outbreaks (on Robs Woodlands Link) travel west to east when a parrallel storm line just off lake Manitoba heading towards Wpg veered south to merge with the line from western MB at Elie.
Note my MB "personal" up close experience has been MB Tornadoes with apologies to St. Malo and Vita Altona and others come from the West or the North and the US outbreaks seldom make it up here.