Severe weather outbreak? March 23-24 - Plains/Midwest

[6SpeedTA95]

Latest data coming in now, 00Z tuesday now showing 56* dewpoint to 59* depending on the model...that is a fairly substantial change.

[KWT]

Yep its a big difference in this set-up 56f gets a moderate type severe event, get close to 60f and we get close to a high type severe event. Need to watch over the next 12hrs to see what the dew points actually do. Still looks like an eveing event as well.

[Ed Mahmoud]

The dry line may be starting to form up between Dodge City, Liberal and Garden City. The dry line should mix through Dodge City shortly, but wind and dewpoint spreads are becoming more noticeable.

I think the dry line can be extended South in the clear air of SW Kansas from that area of clouds in NW Kansas.

[CrazyC83]

Triple point area should be the first place to watch.

MESOSCALE DISCUSSION 0238
NWS STORM PREDICTION CENTER NORMAN OK
1013 AM CDT MON MAR 23 2009

AREAS AFFECTED...S CENTRAL SD INTO MUCH OF NEB E OF THE PANHANDLE

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 231513Z - 231715Z

SEVERE WEATHER POTENTIAL IS FORECAST TO CONTINUE INCREASING FROM S
CENTRAL SD SWD ACROSS THE CENTRAL THIRD OF NEB. TORNADO WATCH WILL
LIKELY BE REQUIRED IN THE NEXT 1-2 HOURS.

LATEST WV IMAGERY SHOWS ASCENT INCREASING ACROSS WRN NEB AHEAD OF AN
UPPER CIRCULATION NOW CENTERED OVER NERN CO. THIS ASCENT -- ALONG
WITH STRONG COLD ADVECTION IN THE LOWER TO MID TROPOSPHERE SPREADING
ENEWD ACROSS NEB -- SHOULD CONTINUE TO WEAKEN THE CAPPING INVERSION
OBSERVED IN ROUGHLY THE 800 TO 600 MB LAYER PER MORNING RAOBS.
CONVECTION IS INCREASING OVER WRN NEB...WITH DEVELOPMENT LIKELY TO
SPREAD EWD INTO CENTRAL NEB WITH TIME AS ASCENT INCREASES AND CAP
WEAKENS.

MODEST BOUNDARY-LAYER MOISTURE /DEWPOINTS NEAR 50F OVER MOST OF THE
NEB WARM SECTOR/ IS INDICATED ACROSS THIS REGION...BUT STEEPENING
MID-LEVEL LAPSE RATES WILL RESULT IN SUFFICIENT INSTABILITY FOR
VIGOROUS UPDRAFT DEVELOPMENT.

STORM MODE SHOULD INITIALLY BE CELLULAR...BUT PROXIMITY OF THE
MID-LEVEL CLOSED LOW IS YIELDING A COMPLEX WIND FIELD WITH HEIGHT --
NOT CLEARLY SUPPORTIVE OF LONG-LIVED/STRONGLY-ROTATING STORMS.
HOWEVER...GIVEN THE OVERALL STRENGTH OF THE FLOW
FIELD...ORGANIZED/ROTATING UPDRAFTS SHOULD EVENTUALLY EVOLVE AS
STORMS INCREASE IN COVERAGE/INTENSITY THROUGH MIDDAY/EARLY
AFTERNOON.

ATTM...HAIL APPEARS TO THE PRIMARY SEVERE POTENTIAL...WITH DAMAGING
WIND GUSTS ALSO POSSIBLE. MODEST BOUNDARY-LAYER MOISTURE SHOULD
LIMIT THE OVERALL TORNADO POTENTIAL TO SOME DEGREE...BUT
LOCALLY-STRONG LOW-LEVEL VEERING/SHEAR -- PARTICULARLY E AND NE OF
THE WRN NEB SURFACE LOW AND NEAR/N OF THE WARM FRONT OVER CENTRAL
NEB -- SUGGESTS THAT A FEW TORNADOES WILL BE POSSIBLE.

..GOSS.. 03/23/2009


ATTN...WFO...FSD...OAX...GID...LBF...UNR...

LAT...LON 42150101 42630136 43050087 43449944 42669779 41649690
40569604 40029756 40410014 41260039 42150101

[CrazyC83]

EARLY 1630Z: No change in the moderate area, but a greater tornado threat farther north.

SPC AC 231536

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1036 AM CDT MON MAR 23 2009

VALID 231630Z - 241200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF CNTRL AND ERN KS
AND NRN OK...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA
FROM N TX INTO MID MO AND MID MS VLYS...

OVERALL SCENARIO DISCUSSED IN PRIOR/13Z/ DY1 OUTLOOK IS ON TRACK.
INTENSE UPPER VORT/LOW BECOMING VERTICAL WITH STRONG SURFACE LOW
SWRN NEB AND TRACKS NEWD INTO SERN SD BY 12Z TUE. 50-60KT LLJ
CONTINUES TO STREAM A MOIST AND INCREASINGLY UNSTABLE AIRMASS NWD
AHEAD OF THE COLD FRONT DRY LINE WHICH EXTENDS SWD FROM LOW CENTER
THRU WRN KS INTO TX PANHANDLE ATTM.

STRONG ASCENT AND MID LEVEL COOLING WILL QUICKLY ERODE THE CINH OVER
NEB INTO SRN SD AHEAD OF LOW WITH SEVERE THUNDERSTORMS DEVELOPING BY
EARLY AFTERNOON. FURTHER S INTO KS AND OK SEVERE THUNDERSTORMS WILL
GRADUALLY FORM LATER THIS AFTERNOON AS HEATING AND ASCENT REMOVE THE
CURRENT SUBSTANTIAL INHIBITION.

...S CNTRL/ERN SD SWD INTO CNTRL/ERN NEB AND N CNTRL KS TODAY...

REF MCD 238

ALTHOUGH BOUNDARY LAYER MOISTURE WILL REMAIN COMPARATIVELY LIMITED
/SFC DEWPOINTS IN THE LOW 50S/...WITH 500 MB TEMPS AROUND MINUS 20
C...MODEST SFC HEATING SHOULD BOOST SBCAPE TO AOA 500 J/KG.
COMBINATION OF DESTABILIZATION AND INCREASING ASCENT WILL SUPPORT
TSTM DEVELOPMENT ALONG COLD FRONT/OCCLUSION BY 18Z THROUGH LATE THIS
AFTN FROM S CNTRL SD ACROSS CNTRL NEB INTO N CNTRL KS.

DEEP SHEAR WILL BE STRONG /40-50 KTS/ THROUGHOUT REGION...ALTHOUGH
WITH A SUBSTANTIAL COMPONENT ORIENTED PARALLEL TO FRONT IN SD AND
NEB. OVERALL SETUP SHOULD YIELD A FEW SUSTAINED STORMS WITH A
THREAT FOR SVR HAIL/WIND. ASSUMING THE PRESENCE OF SUSTAINED
UPDRAFTS...BACKED LOW-LVL FLOW NE OF SFC LOW IN NRN NEB AND SRN SD
ALSO WILL BE FAVORABLE FOR LOW LVL STORM ROTATION/TORNADOES
...BEFORE FRONT AND DEEP ASCENT OUTRUN LOW LVL MOIST AXIS LATE IN
THE DAY. VERTICAL SHEAR PROFILES WILL BE MORE CONDUCIVE FOR TORNADIC
SUPERCELLS WITH SWD EXTENT AND THE TORNADO PROBABILITIES HAVE BEEN
INCREASED ACCORDINGLY NWD INTO SERN NEB.

..CNTRL/ERN KS SSW INTO MUCH OF OK/NW TX LATE TODAY/TONIGHT...
DEEP FORCING FOR ASCENT AND MID LVL COOLING WILL REMAIN WEAK FROM
CNTRL KS SW ACROSS OK AND NW TX TODAY AS LEAD SPEED MAX/UPR VORT
LIFT NE INTO NEB/SD. COUPLED WITH RELATIVELY LIMITED BOUNDARY LAYER
MOISTURE AND SUBSTANTIAL EML CAP ON S SIDE OF UPR JET...EXPECT
LITTLE IF ANY TSTM DEVELOPMENT TIL LATE IN THE DAY OVER OK AND NW
TX. SCTD STORMS MAY...HOWEVER...CONTINUE TO DEVELOP SLOWLY SWD
ALONG FRONT IN KS.

BY EARLY EVE...ASCENT WITH UPSTREAM JET DISTURBANCE SHOULD BEGIN TO
OVERSPREAD THE SRN PLNS AS COLD FRONT OVERTAKES PRE-FRONTAL
TROUGH/DRY LINE. COMBINATION OF STRENGTHENING ASCENT WITH SLOWLY
INCREASING BOUNDARY LAYER MOISTURE /SFC DEWPOINTS IN THE UPR 50S TO
NEAR 60 F/ MAY SUPPORT INCREASED STORM COVERAGE/STRENGTH ALONG THE
FRONT IN KS...AND DEVELOPMENT OF OTHER STORMS SW ALONG FRONT OR DRY
LINE INTO OK.

50+ KT DEEP SHEAR OVER REGION WILL BE ORIENTED AT A CONSIDERABLE
ANGLE TO THE FRONT. GIVEN SUSTAINED UPDRAFTS...THIS SHOULD ALLOW
FOR THE DEVELOPMENT OF ELONGATED SUPERCELL STRUCTURES WITH A GOOD
THREAT FOR LARGE HAIL AND HIGH WIND. IN ADDITION...35-40 KT 0-1 KM
SHEAR WITH A SUBSTANTIAL DIRECTIONAL COMPONENT /ASSOCIATED WITH 60KT
SSWLY LOW LVL JET/...SUGGESTS POTENTIAL FOR STRONG TORNADOES
...IF SUSTAINED SEMI-DISCRETE STORMS DO INDEED FORM.

..HALES/JEWELL.. 03/23/2009

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
CURRENT UTC TIME: 1554Z (11:54AM), RELOAD THIS PAGE TO UPDATE THE TIME

[KWT]

Very interesting Crazy, should see some watches go up pretty soon as well from the sounds of things, though the main activity still likely a good 8-10hrs away I suspect.

[Ed Mahmoud]

EARLY 1630Z: No change in the moderate area, but a greater tornado threat farther north.

They also expanded the hatched tornado area farther North.

[RL3AO]

Dew Points in the mid 50s over the MDT risk area with some upper 50's south of Oklahoma City.

[KWT]

The upper 50s will be enough to give some decent severe weather I'd have thought, still got another 6hrs at least for those dew point to rise quickly as well.

[Ed Mahmoud]

Winds near 40 mph in Central Kansas.

Russell, KS observation.

Wind dynamics should go a ways to making up for less than optimal instability and limited dewpoints.

[RL3AO]

A few very weak cells are trying to get going in SW Nebraska.

[KWT]

Yep there are a few cells trying to go up, somewhat earlier then I thought would be the case as well, though these cells don't look all that potent. Still may see a severe thunderstorm watch soon.

Also not a bad wind gusts there Ed, certainly is quite a decent lower level flow there.

[Ed Mahmoud]

I assume SPC will request relevant NWS offices in Oklahoma through Nebraska release a special 18Z radio-balloon sonde, so add about an hour to the 40 minutes before the balloons are released for the info to appear on the SPC web site, and we may have a better feel for how this outbreak may develop.

[RL3AO]

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 53
NWS STORM PREDICTION CENTER NORMAN OK
1220 PM CDT MON MAR 23 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

LARGE PART OF CENTRAL AND EASTERN NEBRASKA
PARTS OF SOUTHERN SOUTH DAKOTA

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 1220 PM UNTIL
700 PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES EAST NORTHEAST OF
PIERRE SOUTH DAKOTA TO 50 MILES SOUTH SOUTHEAST OF HASTINGS
NEBRASKA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

DISCUSSION...VIGOROUS UPPER TROUGH AND DEEP SURFACE LOW SWRN NE WITH
STRONG LOW LEVEL JET PROVIDING A MOIST/UNSTABLE AIRMASS ACROSS WATCH
AREA. WITH ADDITIONAL HEATING...THUNDERSTORMS EXPECTED TO RAPIDLY
INCREASE IN NUMBER AND INTENSITY AHEAD OF LOW AND TROUGH WITH SHEAR
MORE THAN SUFFICIENT FOR DEVELOPMENT OF SUPERCELLS. ALONG WITH
LARGE HAIL/DAMAGING WINDS...TORNADOES WILL BE POSSIBLE WITH ANY
SUPERCELL AS THEY MOVE RAPIDLY NEWD ACROSS THE WATCH DURING THE
AFTERNOON.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 20040.


...HALES

Theres that one cell just to the SW of the watch box thats getting going pretty well.

[Cookie]

http://chasercentral.com/?page_id=96

mike brady is on the move

[RL3AO]

And we're off.

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HASTINGS NE
1237 PM CDT MON MAR 23 2009

THE NATIONAL WEATHER SERVICE IN HASTINGS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
WESTERN DAWSON COUNTY IN SOUTH CENTRAL NEBRASKA

* UNTIL 115 PM CDT

* AT 1235 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM PRODUCING QUARTER SIZE HAIL. THIS STORM WAS
LOCATED 17 MILES SOUTHWEST OF WILLOW ISLAND...OR 26 MILES WEST OF
LEXINGTON...AND MOVING NORTH AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
WILLOW ISLAND BY 110 PM CDT
GOTHENBURG AND COZAD BY 115 PM CDT

[CrazyC83]

MESOSCALE DISCUSSION 0240
NWS STORM PREDICTION CENTER NORMAN OK
1239 PM CDT MON MAR 23 2009

AREAS AFFECTED...CENTRAL KS INTO NRN OK

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 231739Z - 231915Z

INCREASING CONVECTIVE DEVELOPMENT IN A N-S BAND ACROSS THE CENTRAL
THIRD OF KS AND INTO NWRN OK WILL REQUIRE WW ISSUANCE SOON.

A SHARPENING DRYLINE IS BULGING NEWD ACROSS WRN KS AND THE TX/OK
PANHANDLES ATTM...AS HEATING CONTINUES W OF THE LOW CLOUD BAND OVER
THE ERN HALF OF KS/CENTRAL AND ERN OK. DEWPOINTS IN THE LOW TO MID
50S AND TEMPERATURES NOW INTO THE LOW 70S HAS RESULTED IN THE
DEVELOPMENT OF ROUGHLY 500 J/KG MIXED-LAYER CAPE...WHICH IS
SUPPORTING TCU/SMALL CB DEVELOPMENT ALONG THE DRYLINE.

AS AIRMASS FURTHER DESTABILIZES SUPPORTING CONTINUED CONVECTIVE
DEVELOPMENT...EXISTING SHEAR PROFILES ACROSS THIS REGION --
DEPICTING FLOW INCREASING/VEERING WITH HEIGHT -- WILL SUPPORT
SUPERCELLS. WHILE MODEST BOUNDARY-LAYER MOISTURE SUGGESTS
RELATIVELY HIGH CLOUD BASES...A FEW TORNADOES WILL BE POSSIBLE ALONG
WITH HAIL AND DAMAGING WINDS.

..GOSS.. 03/23/2009


ATTN...WFO...TOP...ICT...OUN...GID...DDC...

LAT...LON 38999643 37809657 36399726 35609874 38749862 39919903
39989653 38999643

[RL3AO]

SVR in ND to the SE of Bismarck.

[CrazyC83]

One thing for sure - this is developing quite a bit sooner than I first expected. I wasn't expecting much until around the dinner hour...

[CrazyC83]

Only valid until 7 pm, which is quite a surprise.

SEL4

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 54
NWS STORM PREDICTION CENTER NORMAN OK
105 PM CDT MON MAR 23 2009

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

LARGE PART OF CENTRAL KANSAS
PARTS OF NORTHERN OKLAHOMA

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 105 PM UNTIL 700
PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHEAST OF
CONCORDIA KANSAS TO 15 MILES SOUTHEAST OF ENID OKLAHOMA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU4).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION...CONTINUE...WW 53...

DISCUSSION...HEATING HAS DISSIPATED THE INHIBITION ALONG THE DRY
LINE ALLOWING SURFACE BASED CONVECTION TO DEVELOP ALONG WRN EDGE OF
WATCH. WITH VERY FAVORABLE DEEP LAYER SHEAR AND ADEQUATE
INSTABILITY SUPERCELLS ARE LIKELY TO DEVELOP AS STORMS INCREASE IN
NUMBER ALONG DRY LINE. IN ADDITION TO DAMAGING WINDS AND LARGE
HAIL...TORNADOES ARE POSSIBLE WITH ANY SUPERCELL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 22045.


...HALES