Jump to content
  • Member Statistics

    17,603
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

June 23rd to June 28th Severe Threat


Stebo

Recommended Posts

Day 3/4 SPC outlook highlighting the plains for more severe convection, also the models advertise a fast zonal flow after Day5 across the Northern Plains into the Upper Midwest.

day3prob_0730.gif

DAY 3 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0216 AM CDT WED JUN 22 2011

VALID 241200Z - 251200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM WY...SEWD ACROSS THE CNTRL

PLAINS INTO THE TN VALLEY...EXTENDING NEWD INTO THE MIDDLE ATLANTIC

AND ERN NY...

...SYNOPSIS...

A MEANDERING ZONE OF POTENTIAL FOR SEVERE THUNDERSTORMS WILL EXTEND

FROM WY...SEWD ACROSS THE CNTRL PLAINS INTO THE TN VALLEY BEFORE

ARCING NEWD INTO SRN NY. THIS ZONE OF POTENTIAL ORGANIZATION IS

ALONG THE SRN FRINGES OF STRONGER FLOW ALOFT WHERE SUFFICIENT

INSTABILITY WILL EXIST FOR DEEP CONVECTION.

...WY INTO THE CNTRL PLAINS...

SCATTERED TO NUMEROUS THUNDERSTORMS...SOME OF WHICH MAY BE

SEVERE...WILL LIKELY DEVELOP OFF THE HIGHER TERRAIN OF WY DURING THE

AFTERNOON WITHIN DIFFLUENT UPPER FLOW REGIME. ALTHOUGH HIGH LEVEL

FLOW IS NOT EXPECTED TO BE THAT STRONG...SUBSTANTIAL VEERING WITH

HEIGHT WILL PROVE QUITE FAVORABLE FOR ROTATING UPDRAFTS AND

SUPERCELLS. MOIST ELY COMPONENT IN LOW LEVELS WILL ALSO ENHANCE

CONVERGENCE WITHIN THE BOUNDARY LAYER WHICH SHOULD ENSURE A

SIGNIFICANT NUMBER OF UPDRAFTS EVOLVE...BOTH OVER THE MOUNTAINS AND

ACROSS THE PLAINS WHERE UPSLOPE FLOW WILL BE EVIDENT. THIS ACTIVITY

SHOULD MIGRATE TOWARD THE CNTRL PLAINS AIDED BY LOW LEVEL WARM

ADVECTION ALONG NOSE OF LLJ. WHILE LARGE HAIL MAY BE THE GREATEST

THREAT...TORNADOES CAN ALSO BE EXPECTED GIVEN THAT SFC DEW POINTS

WILL LIKELY CREEP INTO THE UPPER 50S TO NEAR 60 ACROSS EXTREME ERN

WY.

day48prob.gif

DAY 4-8 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

0327 AM CDT WED JUN 22 2011

VALID 251200Z - 301200Z

...DISCUSSION...

HEIGHTS ARE EXPECTED TO GRADUALLY RISE ACROSS THE MIDDLE OF THE U.S.

DURING THE MEDIUM RANGE PERIOD...THOUGH THE ECMWF AND GFS DISAGREE

ON THIS EVOLUTION. PRIOR TO A MORE SUBSIDENT FLOW REGIME OVER THE

MIDDLE OF THE COUNTRY A SUBSTANTIAL AMOUNT OF CONVECTION COULD

DEVELOP ACROSS PARTS OF THE NRN/CNTRL HIGH PLAINS BENEATH MODEST

SWLY FLOW ALOFT. IT APPEARS STRONG DIURNAL HEATING ALONG WRN FRINGE

OF MOIST BOUNDARY LAYER WILL PROVE ADEQUATE IN STRONG/SEVERE

THUNDERSTORM DEVELOPMENT FROM ERN MT/WRN ND...SWD INTO THE NEB

PANHANDLE SATURDAY. ORGANIZED ACTIVITY COULD DEVELOP AGAIN ACROSS

THIS REGION DAY5 BUT MODELS BEGIN TO DIVERGE SOMEWHAT IN LATER

PERIODS SO CONFIDENCE WANES SOME EARLY NEXT WEEK.

Figured I was a billion posts in, so wouldn't hurt to start a thread for once. :P

Link to comment
Share on other sites

  • Replies 270
  • Created
  • Last Reply

Right on cue with the summer solstice, the GFS is advertising one of my favorite types of events for tomorrow night... The massive overnight MCS pushing SSE out of eastern CO and southern KS into Oklahoma. Maybe it's all the hatching insects or something, but the gust fronts from these are ultra-bright on radar, and push well out in front. Birds are zipping around, little micro-vortices are spinning up all over the place. A lot to see.

Actually seems like climo has been pushed back by 4-7 days or something this year, anecdotally I feel like we usually get these events a little bit earlier.

Link to comment
Share on other sites

It's also my favorite time of year in and around the Black Hills and western SD. Right as the ridge builds in from the east, there seems to be a week or two of southeast surface flow into that region. They need southeast flow to bring in the upper 50s and lower 60s dews... even a straight south flow will dry it out. Storms fire in the Black Hills and sometimes in the Badlands, move east off the hills and into the plains overnight. It's these occurrences in the summer that really enhanced my love of weather, being able to get out on the bike... sit around til around 2 or 3 and watch the towering cu up in the hills grow in to rotating meso's

Now, I just watch from afar, one radar and wait for these to move off the plains and into eastern NE, waking me up at 2 or 3 in the morning

Link to comment
Share on other sites

It's also my favorite time of year in and around the Black Hills and western SD. Right as the ridge builds in from the east, there seems to be a week or two of southeast surface flow into that region. They need southeast flow to bring in the upper 50s and lower 60s dews... even a straight south flow will dry it out. Storms fire in the Black Hills and sometimes in the Badlands, move east off the hills and into the plains overnight. It's these occurrences in the summer that really enhanced my love of weather, being able to get out on the bike... sit around til around 2 or 3 and watch the towering cu up in the hills grow in to rotating meso's

Now, I just watch from afar, one radar and wait for these to move off the plains and into eastern NE, waking me up at 2 or 3 in the morning

Totally agree. I love Black Hills convection. Some of the most unique convection because they receive enhancement via slope flows and enhanced convergent boundaries, but they also have an influence of higher dewpoint values of the lower surrounding plains than the other ranges across the high plains in WY/CO.

Link to comment
Share on other sites

Totally agree. I love Black Hills convection. Some of the most unique convection because they receive enhancement via slope flows and enhanced convergent boundaries, but they also have an influence of higher dewpoint values of the lower surrounding plains than the other ranges across the high plains in WY/CO.

Right where tornados belong, over baren land.

Link to comment
Share on other sites

Southern Saskatchewan

TORNADO WARNING
ISSUED BY ENVIRONMENT CANADA
AT 7:07 PM CST THURSDAY 23 JUNE 2011.
---------------------------------------------------------------------
TORNADO WARNING FOR:
=NEW= R.M. OF ARLINGTON INCLUDING DOLLARD
=NEW= R.M. OF GRASSY CREEK INCLUDING SHAUNAVON.

---------------------------------------------------------------------
==DISCUSSION==
AT 7:00 PM CST, ENVIRONMENT CANADA METEOROLOGISTS ARE TRACKING A
SEVERE THUNDERSTORM NEAR SHAUNAVON CAPABLE OF PRODUCING A TORNADO.
GOLF BALL HAIL HAS BEEN REPORTED WITH THIS STORM.

THIS IS A WARNING THAT SEVERE THUNDERSTORMS WITH TORNADOES ARE
IMMINENT OR OCCURRING IN THESE REGIONS.  MONITOR WEATHER CONDITIONS.
TAKE IMMEDIATE SAFETY PRECAUTIONS.

Link to comment
Share on other sites

Here is warning text you do not see often. This comes from the National Weather Service in Birmingham AL:

BULLETIN - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WARNING

NATIONAL WEATHER SERVICE BIRMINGHAM AL

451 PM CDT FRI JUN 24 2011

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

CENTRAL JEFFERSON COUNTY IN ALABAMA...

SOUTHWESTERN ST. CLAIR COUNTY IN ALABAMA...

NORTHERN SHELBY COUNTY IN ALABAMA...

CENTRAL TALLADEGA COUNTY IN EAST CENTRAL ALABAMA...

* UNTIL 530 PM CDT

* AT 449 PM CDT...THE NATIONAL WEATHER SERVICE INDICATED A

DEVELOPING LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING

DESTRUCTIVE WINDS IN EXCESS OF 70 MPH. THESE STORMS WERE LOCATED

ALONG A LINE EXTENDING FROM BALD ROCK TO BLUFF PARK...AND MOVING

SOUTHEAST AT 15 MPH.

* LOCATIONS IMPACTED INCLUDE...

HOOVER...PELHAM...PELL CITY...CHELSEA...ROSS BRIDGE...BLUFF PARK...

GREYSTONE AND LAKE PURDY.

Link to comment
Share on other sites

Monday still looks kinda interesting. NAM in particular is hinting at nicely backed low level flow in northern/central IL and IN with mid level winds of 40-50 kts. Overall setup looks favorable for a nice MCS with all modes of svr on the table.

Link to comment
Share on other sites

Monday still looks kinda interesting. NAM in particular is hinting at nicely backed low level flow in northern/central IL and IN with mid level winds of 40-50 kts. Overall setup looks favorable for a nice MCS with all modes of svr on the table.

Indeed. With the amount of low-level turning, one would think that even an MCS would be the kind with perhaps an abnormally high tornado production rate...

Link to comment
Share on other sites

Warmer mid level temps = more CAPE and more CAP. From what I have heard that is a crappy tradeoff and April is much better than June. Hardly any H% height falls to speak of, and when was then last time an EF4 or 5 occured in an area with +20C 850 Temps?

Link to comment
Share on other sites

Whoa, pretty intense supercell NW of Farmington, MO right now.

MOC186-187-260445-

/O.CON.KLSX.TO.W.0130.000000T0000Z-110626T0445Z/

STE. GENEVIEVE MO-ST. FRANCOIS MO-

1118 PM CDT SAT JUN 25 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR ST. FRANCOIS AND STE.

GENEVIEVE COUNTIES UNTIL 1145 PM CDT...

AT 1110 PM CDT...MISSOURI HIGHWAY PATROL REPORTED A FUNNEL CLOUD

NEAR BONNE TERRE WITH THIS STORM. THIS IS A DANGEROUS STORM! SEEK

SHELTER NOW! THIS TORNADO WAS LOCATED BETWEEN BONNE TERRE AND

DESLOGE...MOVING EAST AT 30 MPH.

LOCATIONS IMPACTED INCLUDE...

ROCKY RIDGE...WEINGARTEN...COFFMAN...LEADINGTON...FRENCH VILLAGE

AND RIVER AUX VASES.

Link to comment
Share on other sites

Warmer mid level temps = more CAPE and more CAP. From what I have heard that is a crappy tradeoff and April is much better than June. Hardly any H% height falls to speak of, and when was then last time an EF4 or 5 occured in an area with +20C 850 Temps?

It looks like they were around +18 here on May 22nd.

Link to comment
Share on other sites

Amazing lightning show here in Western Illinois this evening. I was at a drive in so I had a great 360 view and a dark sky. Probably the best lightning display I've ever seen. Not sure how much rain we got this evening but we got almost 3 inches this morning. Good buddy of mine is in Florrisant, Mo is without power right now. It went out around 11:30pm.

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...