Jump to content
  • Member Statistics

    17,586
    Total Members
    7,904
    Most Online
    23Yankee
    Newest Member
    23Yankee
    Joined

June 29th - July 4th Severe Weather Threat


SEMIweather

Recommended Posts

  • Replies 416
  • Created
  • Last Reply

Moved from the other thread:

day3otlk_0730.gif

SPC AC 280721

DAY 3 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0221 AM CDT TUE JUN 28 2011

VALID 301200Z - 011200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN

PLAINS...

...NRN PLAINS/MID TO UPPER MS VALLEY...

AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE QUICKLY NEWD ACROSS THE

NRN AND CNTRL HIGH PLAINS ON THURSDAY. AHEAD OF THE UPPER-LEVEL

TROUGH...THE THERMODYNAMIC ENVIRONMENT ACROSS THE NRN PLAINS SHOULD

BE IMPRESSIVE WITH SEVERAL MODEL FORECASTS SHOWING STRONG TO EXTREME

INSTABILITY WITH MLCAPE VALUES IN THE 3500 TO 5000 J/KG RANGE. DUE

TO AN EXITING UPPER-LEVEL RIDGE TO THE EAST...A STRONG CAPPING

INVERSION IS FORECAST FOR MUCH OF THE DAY WHICH SHOULD SUPPRESS

CONVECTIVE INITIATION. THE CAP IS FORECAST TO WEAKEN FIRST ACROSS

ERN MT AND NE WY WHERE STORMS MAY INITIATE DURING THE LATE

AFTERNOON. FURTHER EAST ACROSS THE DAKOTAS...INITIATION IS EXPECTED

TO HOLD OFF UNTIL EARLY EVENING AS THE CAP WEAKENS AND A LOW TO

MID-LEVEL JET MOVES IN FROM THE SOUTHWEST. THIS JET ALONG WITH THE

STRONG INSTABILITY SHOULD CREATE AN ENVIRONMENT FAVORABLE FOR SEVERE

STORMS. THE GREATEST POTENTIAL FOR SUPERCELL DEVELOPMENT IS FORECAST

ACROSS CNTRL AND ERN ND WHERE THE MODELS MAXIMIZE THE COMBINATION OF

INSTABILITY AND DEEP LAYER SHEAR. A SEVERE THREAT MAY EXTEND AS FAR

SOUTH AS SRN SD WHERE MODERATE DEEP LAYER SHEAR AND STEEP MID-LEVEL

LAPSE RATES SHOULD EXIST BUT CONVECTIVE INITIATION MAY BE MORE

ISOLATED. AS STORMS INCREASE IN COVERAGE DURING THE EVENING...THE

SEVERE THREAT IS EXPECTED TO PERSIST EWD INTO NW MN. AN ISOLATED

SEVERE THREAT COULD ALSO EXTEND SWD ACROSS THE UPPER TO MID-MS

VALLEY WHERE STRONG INSTABILITY IS FORECAST BUT THE WARM TEMPS ALOFT

SHOULD KEEP ANY CONVECTION VERY ISOLATED.

..BROYLES.. 06/28/2011

I also see Manitoba as a potential hotspot on Thursday as well.

Link to comment
Share on other sites

Things are looking good in southern Manitoba on Thursday. A strong shortwave looks to push through by evening which should be enough to break the cap. With up to 5,000 J/KG of CAPE and 40-50 kts of bulk shear, the stage will be set for supercells. Moisture looks good. There's a good trigger with the front. Only thing I would like to see more of is a LLJ. Looks a bit meager to me.

Link to comment
Share on other sites

DTX

SATURDAY LOOKS TO BE THE MORE INTERESTING DAY. A WEAK COLD FRONT

WILL SLOWLY SAG SOUTH ACROSS THE AREA ON SATURDAY. LATEST 12Z GFS

BUFR SOUNDINGS SHOW SBCAPE VALUES CLIMBING TO NEARLY 4000 J/KG.

ALTHOUGH THIS IS LIKELY TOO HIGH GIVEN THE 75+ SURFACE DEWPOINTS

FORECASTED BY THE GFS...MODIFIED SOUNDINGS WITH A 71F SURFACE

DEWPOINT STILL GIVE SBCAPE VALUES AROUND 3000 J/KG WITH CIN VALUES

AROUND 100 J/KG. THIS CAP...ALTHOUGH WEAKER IN THE NORTHERN CWA...IS

SOMEWHAT CONCERNING GIVEN VERY LITTLE SYNOPTIC FORCING WITH THE MAIN

SHORTWAVE WELL NORTH OF THE REGION IN ONTARIO. CHANCES FOR

CONVECTION MAY DEPEND ON UPSTREAM MCS DEVELOPMENT IN ORDER TO

OVERCOME THIS CAP. IF CONVECTION DOES MANAGE TO INITIATE...IT WILL

NOT BE DIFFICULT TO ORGANIZE GIVEN 40+ KNOTS AT 500MB AND 25+ KNOTS

AT 850MB IN A LARGELY UNIDIRECTIONAL WIND PROFILE. DEEPER MIXING AND

A SLIGHTLY WARMER AIRMASS WILL ALLOW HIGH TEMPS ON SATURDAY TO MAKE

A RUN AT THE LOWER 90S BUT THIS IS LARGELY DEPENDENT ON THE TIMING

OF POSSIBLE CONVECTION.

Link to comment
Share on other sites

18Z NAM/GFS are looking pretty favorable for development in Southern Manitoba/Northeastern ND/Northern MN for Thursday evening.

The cap is going to be the problem, surface DP's are likely too high. I wish we had a little more backing of the winds at the surface as well, but if something does go up it'll have a shot. Also lcl's would also likely be higher with a lower DP than being forecasted but we'll just have to see.

Link to comment
Share on other sites

Geez...the 0z GFS has good deal more instability around here on saturday compared to the 12z run and is breaking out precip along the frontal boundary in IA/IL. The bulk shear isn't that great but some serious juice thats for sure.

This is a fun time of year. You often struggle to have really good shear but the juice is loose as they say.

Link to comment
Share on other sites

This is a fun time of year. You often struggle to have really good shear but the juice is loose as they say.

Yeah this is the time of year when obscene amounts of instability can just take over and create very interesting storm events. 6000j/kg of cape forecast by the GFS is pretty impressive. That means the RUC will forecast over 10000j/kg of cape by the time we get to the weekend lol.

Link to comment
Share on other sites

Yeah this is the time of year when obscene amounts of instability can just take over and create very interesting storm events. 6000j/kg of cape forecast by the GFS is pretty impressive. That means the RUC will forecast over 10000j/kg of cape by the time we get to the weekend lol.

Yeah I'm sure the RUC will be nuts. Probably SBCAPE of 8000-9000+ :guitar:

Link to comment
Share on other sites

Probably gonna have a hell of an EML, but if we can get an MCS to grow upscale/turn right into an environment with a mature cool pool then....... :guitar:

The EML is only really bad on friday, both saturday and sunday its decent as the GFS is breaking out precip as early as late friday night-saturday morning.

Link to comment
Share on other sites

I'm still leery of the model DP's we do have a ton of standing water and what little crops we have will tend to release some water but 80 DP's are a bit to high I'd go with the 75-77 DP range the NWS has for us. It'll probably be a nocturnal event for us and we'll watch the good stuff smoke MN but we'll see.

Link to comment
Share on other sites

Can you imagine if we had the winter/spring-intensity jets in the summer?

Also: New Day 2, it is rather conditional, but development is expected in some form or another and could become significant.

day2probotlk_0600_any.gif

SPC AC 290548

DAY 2 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1248 AM CDT WED JUN 29 2011

VALID 301200Z - 011200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN PLAINS

AND UPPER MS VALLEY...

...NRN PLAINS/UPPER MS VALLEY...

AN UPPER-LEVEL TROUGH IS FORECAST TO APPROACH THE NRN PLAINS

THURSDAY AS A MID-LEVEL JET STRENGTHENS AND MOVES INTO THE REGION

FROM THE SOUTHWEST. THIS WILL TAKE PLACE ACROSS A BROAD WARM SECTOR

ACROSS THE NRN PLAINS AND UPPER MS VALLEY. ALTHOUGH THE MODELS SHOW

A STRONGLY TO EXTREMELY UNSTABLE AIRMASS BY THURSDAY AFTERNOON...A

CAPPING INVERSION WILL LIKELY PREVENT CONVECTIVE INITIATION ACROSS

MOST OF THE REGION UNTIL THE EVENING WHEN LARGE-SCALE ASCENT WILL

INCREASE FROM THE WEST. HOWEVER...THE EXACT TIMING OF CONVECTIVE

INITIATION REMAINS HIGHLY UNCERTAIN DUE TO THE DRASTIC DIFFERENCES

IN THE NAM AND GFS SOLUTIONS. THE GFS SOLUTION WHICH IS CLOSER TO

THE ECMWF SOLUTION...IS MUCH FASTER WITH THE NEWD MOVEMENT OF THE

UPPER-LEVEL TROUGH WHICH COULD RESULT IN RAPID CONVECTIVE

DEVELOPMENT ACROSS NRN SD NEWD ACROSS CNTRL AND ERN ND AFTER 00Z

FRIDAY.

FORECAST SOUNDINGS IN NRN SD AND ERN ND AT 03Z SHOW MLCAPE VALUES IN

THE 3500 TO 5000 J/KG RANGE WITH SOME EVEN HIGHER AND 0-6 KM SHEAR

VALUES OF 45 TO 50 KT. THIS IS AN IMPRESSIVE ENVIRONMENT AND

SUPERCELL DEVELOPMENT APPEARS PROBABLE UPON INITIATION ESPECIALLY

ACROSS ERN ND. HAVE ADDED A 30 PERCENT SEVERE PROBABILITY AND

SIG-HATCHED AREA IN ERN ND AND FAR NW MN WHERE VERY LARGE HAIL COULD

OCCUR. THE ENHANCED SEVERE THREAT AREA IS LOCATED WHERE THE MODELS

MAXIMIZE THE COMBINATION OF INSTABILITY AND DEEP LAYER SHEAR AND ARE

THE MOST IN AGREEMENT CONCERNING STORM INITIATION. SOME TORNADOES

WILL ALSO BE POSSIBLE ESPECIALLY IF THE FASTER GFS SOLUTION VERIFIES

IN WHICH CONVECTION DEVELOPS SOONER AND THE LOW-LEVEL JET MOVES INTO

THE REGION EARLIER. IF A FAST MOVING CLUSTER OF STORMS OR A SMALL

MCS CAN ORGANIZE...THEN A WIND DAMAGE THREAT COULD ALSO EXIST.

FURTHER TO THE EAST IN THE UPPER MS VALLEY...THUNDERSTORM INITIATION

WILL ALSO BE POSSIBLE THURSDAY AFTERNOON ALONG A NORTH TO SOUTH

GRADIENT OF MODERATE TO STRONG INSTABILITY. THE MOST LIKELY LOCATION

FOR STORM INITIATION WOULD BE EAST OF AN UPPER-LEVEL RIDGE AXIS

ACROSS WI...UPPER MI AND NERN IL WHERE THE COMBINATION OF

INSTABILITY AND DEEP LAYER SHEAR WOULD SUPPORT A THREAT FOR HAIL AND

STRONG WIND GUSTS. THE CONVECTIVE THREAT IS EXPECTED TO REMAIN

ISOLATED DUE TO WARM TEMPS ALOFT AND A LACK OF LARGE-SCALE ASCENT.

..BROYLES.. 06/29/2011

Link to comment
Share on other sites

Hoping to make it 2 for 2 this holiday weekend. Last time I was back at IKK, the Sunday before Memorial Day produced a nice derecho/wind event. :scooter:

Me on the other hand would love nothing more than a dry Sunday. It can storm all it wants overnight just as long as I have some dry weather during the day/evening.

Link to comment
Share on other sites

I get the feeling that the North Dakota/Minnesota/Manitoba threat could be real bad tomorrow. I believe the cap gets broken early in the evening. Looks like a round of supercells possible in NE ND/NW MN/S MB during the evening with maybe a severe MCS developing in the central Dakotas after dark.

Really liking tomorrow's set-up!

Link to comment
Share on other sites

I get the feeling that the North Dakota/Minnesota/Manitoba threat could be real bad tomorrow. I believe the cap gets broken early in the evening. Looks like a round of supercells possible in NE ND/NW MN/S MB during the evening with maybe a severe MCS developing in the central Dakotas after dark.

Really liking tomorrow's set-up!

Discrete activity shown on the 12z 4km WRF...

post-147-0-31971200-1309365103.gif

Link to comment
Share on other sites

Discrete activity shown on the 12z 4km WRF...

post-147-0-31971200-1309365103.gif

Thanks for posting that. Would make sense to see development sooner to the north where the cap is less robust. Could get a nice string of pearls along the front if the cap get broken further south. With up to 5,000 J/KG of SB and MLCAPE tomorrow evening, any storm that goes up could drop some monster hail.

Link to comment
Share on other sites

Seeing some rather favorable, curving hodographs on the 18Z GFS within the weakened cap zone for tomorrow afternoon/evening.

Not sure the GFS is going to verify. Seems to be the outlier. The ECMWF and NAM especially are showing a slower frontal/shortwave passage tomorrow. Minot and Grand Forks forecast discussions have mentioned that, too. Would certainly bode well for areas a bit west of the current hatched risk area.

Regardless of what model solution plays out, there is a pretty good chance of discrete supercells late tomorrow afternoon/early evening.

Link to comment
Share on other sites

TOG moving towards Glasgow, MT

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE GLASGOW MT

714 PM MDT WED JUN 29 2011

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

* TORNADO WARNING FOR...

CENTRAL VALLEY COUNTY IN NORTHEAST MONTANA...

* UNTIL 815 PM MDT.

* AT 710 PM MDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO 26

MILES SOUTHWEST OF TAMPICO...OR 28 MILES SOUTHWEST OF GLASGOW...

MOVING NORTHEAST AT 45 MPH.

* LOCATIONS IN THE WARNING INCLUDE...

TAMPICO AND GLASGOW

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM MDT WEDNESDAY EVENING

FOR NORTHEAST MONTANA.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...