[BeauDodson]

The models were correct over the past few weeks in showing a more active pattern for portions of the Central United States. SPC has outlined a large risk zone for Tuesday. Looks like a decent squall line event with some isolated supercells possible. Not a mega event by any means but another severe weather episode similar to Sundays. Thought I would start a thread on the subject.

Drought continues for my region. The squall line last night dried up as it moved eastward. Looks like most of the severe will stay west on Tuesday as well.

[brettjrob]

This does look like a big squall line event somewhat reminiscent of today's across the eastern Plains into the Mid Mississippi Valley. We've certainly entered a more active pattern than has been seen for quite some time around these parts. The 00z ECMWF tonight shows what could be a more interesting scenario for the Plains next Saturday with the next trough coming through the West, but there are large timing differences vs. the GFS (as usual), so I'm not getting too excited yet.

[wxmann_91]

Tuesday does not look like a big outbreak day to me. Lack of LL shear will preclude a bigger tornado threat; high freezing levels preclude a major hail threat. I've just briefly looked at things but it looks like the models want to develop widespread convection across the warm sector, limiting instability. I think a marginally severe squall line with some damaging winds might be all we can muster on Tuesday.

Later next week looks MUCH better but details still are sketchy. If the trough is as positively tilted as the models have been trying to prog it for days, the severe threat might be significantly diminished. Still, given models still have a poor handling of the PAC jet, I will not jump to any conclusions yet. Cap will be a concern as always.

[BeauDodson]

Yes we are definitely entering a more active pattern. Todays outbreak and then another tomorrow. That is active compared to recent events. The long range models show several events in the coming weeks. At least one of those will likely be a biggie.

Agree on Tuesday looking similar to yesterdays event. Squall line with high winds and hail. Some isolated tornadoes possible.

[BeauDodson]

From Wright Weather

Some nice lift/forcing along the system
:)
http://www.beaudodson.com/images/September%20Images/october1sto2007.gif

[BeauDodson]

Someone on StormTrack has started a thread...
http://stormtrack.or...ead.php?t=13759

[BeauDodson]

Springfield, MO - Morning AFD

WITH CONVECTION FIRING ALONG AND AHEAD OF THE
FRONT. THIS CONVECTION WILL LIKELY FORM INTO A LINE AND PUSH INTO
THE WESTERN CWA LATE TUESDAY AFTERNOON OR IN THE EARLY EVENING
HOURS. INSTABILITY WILL ONCE AGAIN BE LIMITED OVER THE AREA...
HOWEVER WIND SHEAR WILL BE STRONG WITH 0-6 KM BULK SHEAR VALUES
40 TO 50KT. GIVEN THE STRONG SHEAR...A FEW SEVERE STORMS WILL
AGAIN BE POSSIBLE WITH DAMAGING WINDS THE MAIN RISK...WITH LARGE
HAIL A SECONDARY RISK. HAVE RAISED POPS QUITE A BIT TUESDAY
EVENING/NIGHT IN LINE WITH THE SLOWER NAM/WRF MODEL. A FEW
LINGERING SHOWERS COULD REMAIN OVER THE AREA ON WEDNESDAY AS THE
COLD FRONT EXITS TO THE EAST SO HAVE INTRODUCED SLIGHT CHANCES FOR
THIS TIME FRAME.



Kansas City

REGARDLESS...UPPER WAVE SUFFICIENT IN DRIVING ANOTHER WEAK COLD FRONT
INTO MISSOURI ON TUESDAY. ALTHOUGH DYNAMICS ARE NOT IMPRESSIVE...IT
APPEARS THAT THIS STORM SYSTEM WILL HAVE A TROPICAL CONNECTION.
LATEST MOISTURE IMAGERY DEPICTS A TROPICAL PLUME SURGING NORTH INTO
SRN AZ AND NM. MODELS LOOK TO HANDLE THE CURRENT SITUATION WELL WITH
THE NAM AND GFS DRIVING A NARROW WEDGE OF TROPICAL MOISTURE NE INTO
KS AND MO BY LATE TUESDAY. GULF MOISTURE WILL ALSO RAPIDLY RETURN ON
TUESDAY WITH THE AID OF A 40 KT LLJ. NAM AND GFS SUGGEST THE
POTENTIAL FOR 2 TO 2.1 INCHES OF PRECIPITABLE WATER ON TUESDAY. FCST
SOUNDINGS SUGGEST LITTLE OR NO CAP WITH THUNDERSTORM DEVELOP AHEAD OF
THE BOUNDARY LIKELY. THE THUNDERSTORMS WILL LIKELY PRODUCE HEAVY
RAINFALL. WIDESPREAD FLOODING DOES NOT LOOK LIKELY AT THIS TIME
GIVEN THE SPEED OF THE FRONT. WILL NOTE HEAVY RAIN POTENTIAL ON THE
HWO PRODUCT.

ANOTHER CONCERN IS THE RISK FOR SEVERE STORMS ON TUESDAY. GIVEN THE
TROPICAL ENVIRONMENT...MID LEVEL LAPSE ARE POOR WITH NAM AND GFS
ONLY SUGGESTING ABOUT 500 J/KG. THE ONLY CONCERN MAY BE THE POTENTIAL
FOR A SQUALL LINE TO DEVELOP ALONG THE FRONT AS SFC-6KM BULK SHEAR
INCREASES TO AROUND 40 KNOTS. THE DEEP MOISTURE ATMOSPHERIC PROFILE
IS UNFAVORABLE FOR DAMAGING WINDS...HOWEVER 40KT EWD MOVING SQUALL
LINE MAY BE ENOUGH TO PRODUCE ISOLATED DAMAGING WIND REPORTS.

Norman, Oklahoma

BUT CURRENTLY
EXPECT BETTER CHANCES OVERNIGHT TO REMAIN TO OUR W AND NW.
INCREASE IN LOW-LEVEL MOISTURE... ALONG WITH INCREASING MOISTURE
ALOFT AND APPROACH OF UPPER TROUGH... LIKELY TO LEAD TO FAIRLY
WIDESPREAD PRECIP/CONVECTION EXPANDING E ACROSS MUCH OF W AND N OK
INTO CENTRAL OK DURING THE DAY ALONG AND AHEAD OF NEXT COLD FRONT.
ALTHOUGH LOW-MID LEVEL SHEAR WILL SUPPORT SEVERE POTENTIAL...
WIDESPREAD CLOUD COVER AND EARLY STORM DEVELOPMENT MAY LIMIT
INSTABILITY. HEAVY/EXCESSIVE RAIN POTENTIAL SHOULD BE LIMITED BY
SPEED OF CONVECTIVE CELLS... ALTHOUGH FRONT MAY FORCE STORMS INTO
A LINEAR STRUCTURE AND SOME TRAINING MAY BE POSSIBLE IF THE FRONT
AND ASSOCIATED CONVECTIVE LINE MOVE ONLY SLOWLY S. HAVE UPPED POPS
TO LIKELY ACROSS THE N FOR TUE AND OVER CENTRAL/SE TUE NIGHT AS
FRONT AND UPPER SYSTEM MOVE INTO MOIST AIR WITH PROGGED PW ABOVE 2
INCHES. QUESTIONS AGAIN EXIST AS TO HOW FAST TO END PRECIP CHANCES
AS FRONT SAGS INTO TX. HAVE PULLED LOW POPS ON WED BACK A TAD
FARTHER N INTO SW/CENTRAL OK. TRANSITION BACK TO RETURN FLOW AND
N-WARD MOISTURE TRANSPORT WILL OCCUR AGAIN WED NIGHT INTO EARLY
THU. CHANCES OF PRECIP/CONVECTION APPEAR SLIGHTLY BETTER THIS TIME AS
ISENTROPIC LIFT AND ELEVATED MOISTURE RETURN ARE A BIT MORE
IMPRESSIVE. THUS HAVE INTRODUCED LOW POPS AREAWIDE BOTH PERIODS.

http://www.spc.noaa.gov/exper/sref/gifs/2007100103/SREF_03HR_SVR_PROBS__f045.gif

[weatherwiz]

wxmann_91, on Oct 1 2007, 03:58 AM, said:

Tuesday does not look like a big outbreak day to me. Lack of LL shear will preclude a bigger tornado threat; high freezing levels preclude a major hail threat. I've just briefly looked at things but it looks like the models want to develop widespread convection across the warm sector, limiting instability. I think a marginally severe squall line with some damaging winds might be all we can muster on Tuesday.

Later next week looks MUCH better but details still are sketchy. If the trough is as positively tilted as the models have been trying to prog it for days, the severe threat might be significantly diminished. Still, given models still have a poor handling of the PAC jet, I will not jump to any conclusions yet. Cap will be a concern as always.

looks like you may be right Jim. Looking at 0z NAM looks like threat tomorrow will mostly be in the form of line segments with embedded supercells possible. Isolated supercells may be possible as well near the sfc low but shear looks to be favorbale for lines. High instability is really in a small area basically in and around portions of KS. NAM is hinting at a possible major squall line tomorrow night into early Wed. am from MO up to near IL/MN. If convection fires too ealry that may also hinder instability and keep discrete storms from forming.

[weatherwiz]

Tomorrow actually is starting to look less impressive. Lackluster SLP falls, meager lapse rates, it appears best 0-6kmshear is NW of the best instability, and helicity values aren't even that high. Low does deepen as it heads NE but unfortunately it will be in the early AM Wed when this occurs and there will be no instability to work with (at least SB, not sure about any elevated instability).

[brettjrob]

I'm still watching the weekend setup with curiosity. The GFS has trended much slower since last night, about in line with last night's ECMWF. Meanwhile, the new ECMWF is even slower, keeping the surface low over the central High Plains into Saturday evening - perhaps an interesting setup for the High Plains region depending on details? Then Sunday evening the upper low closes off over C/W NE with strong dynamics overspreading the eastern Plains, perhaps threatening IA/MO/AR (especially if this slower/more amplified trend continues). I'm no fan of trying to dissect the details from 24-hour timesteps and a short list of variable plots, so I'll leave the analysis to others.

[BeauDodson]

GIVEN POOR LAPSE RATES ALOFT...HAIL DOES NOT APPEAR TO BE THE PRIMARY SVR CONCERN. BUT...DMGG WINDS WILL BE A THREAT WITH BOWING LINE SEGMENTS. MORE DISCRETE STORMS MAY PRODUCE A COUPLE OF TORNADOES...PRIMARILY ACROSS SERN KS INTO CNTRL MO...ALONG NRN PERIPHERY OF MORE SUBSTANTIAL LOW-LEVEL MOISTURE. FARTHER N...BOW HEAD TYPE TORNADOES WILL ALSO BE POSSIBLE INTO THE ECNTRL IA/NWRN IL AREA.

NRN PORTION OF THE EVOLVING SQUALL LINE WILL LIKELY PEAK IN THE EARLY EVENING AS IT MOVES INTO SRN WI...WRN IL AND ECNTRL MO. ACTIVITY SHOULD QUICKLY DIMINISH LATER IN THE EVENING AS IT OUTRUNS THE INSTABILITY AXIS. PROBABILITIES FOR DMGG WIND GUSTS/HAIL WILL LINGER LONGER FARTHER TO THE SW FROM PARTS OF OK NEWD INTO THE OZARKS THROUGH LATE EVENING.

[BeauDodson]

http://wwwt.emc.ncep.noaa.gov/mmb/mmbpll/cent4km/v2/tcolc_f25.gif


http://wwwt.emc.ncep.noaa.gov/mmb/mmbpll/cent4km/v2/tcolc_f28.gif

[BeauDodson]

Springfield MO

STRONG DEEP LAYER SHEAR...40 TO 50 KTS...WILL SPREAD OVER THE
REGION IN ADVANCE OF THE DEEP TROUGH. IN ADDITION A 30-40KT LOW
LEVEL JET WILL BE PRESENT. WITH SFC DEWPOINTS IN THE UPPER 60S
EXPECTED ALONG/AHEAD OF THE SFC COLD FRONT...INSTABILITY SHOULD BE
DECENT WITH MLCAPE VALUES AROUND 1500 TO 2000 J/KG. THE
COMBINATION OF STRONG KINEMATICS AND MODEST INSTABILITY WILL
RESULT IN A RISK FOR SEVERE THUNDERSTORMS...ESPECIALLY OVER THE
WESTERN HALF OF THE FORECAST AREA. CONVECTION ALONG THE FRONT
SHOULD BE LINEAR IN NATURE...HOWEVER OUT AHEAD OF THE FRONT A FEW
DISCREET CELLS ARE POSSIBLE. ALL MODES OF SEVERE WEATHER ALL
PLAUSIBLE. THE PRIMARY RISK WILL BE DAMAGING WINDS WITH THE
PASSAGE OF THE SQUALL LINE. WITH THE DISCREET ACTIVITY OUT AHEAD
OF THE LINE...0-1KM WIND SHEAR WILL BE 20-25KT AND A FEW TORNADOES
ARE POSSIBLE. HAIL WILL BE A BIT TOUGH TO COME BY GIVEN WARM 500MB
TEMPS AND MARGINAL MID LEVEL LAPSE RATES...BUT STRONGER UPDRAFTS
COULD SUPPORT MARGINALLY SEVERE HAIL.

FLASH FLOODING WILL ALSO BE A CONCERN WITH THIS SYSTEM.
PRECIPITABLE WATER VALUES WILL INCREASE TO AROUND 2 INCHES AHEAD
OF THE SFC FRONT...SUPPORTING OF VERY HEAVY DOWNPOURS. HOWEVER...
GIVEN THE PROGRESSIVE NATURE OF THIS SYSTEM IT APPEARS THAT THE
FLASH FLOOD RISK WILL BE SPORADIC IN NATURE AND DEPENDENT ON
WHETHER OR NOT A BRIEF PERIOD OF TRAINING CELLS DEVELOPS. THE MOST
PLAUSIBLE AREA FOR THIS TO OCCUR WILL BE FAR SOUTHWESTERN
MISSOURI. WILL CONTINUE TO HIGHLIGHT THIS RISK IN THE HWO.

[BeauDodson]

Nice influx of moisture...

http://www.spc.noaa.gov/exper/mesoanalysis/s3/tran.gif

http://www.spc.noaa.gov/exper/mesoanalysis/s4/ttd.gif

[BeauDodson]

11 a.m. Eastern - WeatherTap Image

http://www.beaudodson.com/images/October07/october2ndradar1045easternam.gif

[calidude]

We have our first watch up of the day.

Quote

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 700
NWS STORM PREDICTION CENTER NORMAN OK
300 PM CDT TUE OCT 2 2007

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

SOUTHEASTERN KANSAS
SOUTHWEST INTO CENTRAL MISSOURI
NORTH CENTRAL AND NORTHEASTERN OKLAHOMA

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 300 PM UNTIL
1000 PM CDT.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80
STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES NORTH OF
COLUMBIA MISSOURI TO 50 MILES WEST SOUTHWEST OF TULSA OKLAHOMA.
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...THUNDERSTORMS WILL INCREASE WITHIN ERN AND SRN PORTION
OF PRE-FRONTAL CONVECTION WHICH HAS BEEN SUSTAINED OVER SERN KS INTO
WRN/CENTRAL MO AND NRN OK THIS AFTERNOON...WITH FURTHER DEVELOPMENT
POSSIBLE ALONG STRONG SURFACE COLD FRONT MOVING SEWD INTO THE WATCH
THIS EVENING. STRONG HEATING WITHIN AN UNSEASONABLY MOIST BOUNDARY
LAYER WILL SUPPORT AXIS OF MODERATE INSTABILITY FOR SEVERAL MORE
HOURS. GIVEN EFFECTIVE BULK SHEAR FROM 35-45 KT...SUPERCELLS AND
SMALL LINES/BOW ECHOES CAN BE EXPECTED AS STORMS MOVE ENEWD ACROSS
WW THROUGH THE EVENING. DAMAGING WINDS AND ISOLATED LARGE HAIL WILL
BE PRIMARY SEVERE THREATS.

[earthlight]

Latest ssfc looks to be in agreement with spc for the majority..toning down the larger 25% area they had previously this aftn.

http://www.americanw.../outlooks/day1/

[BeauDodson]

http://www.spc.noaa.gov/products/md/mcd2051.gif


http://www.spc.noaa.gov/products/md/mcd2050.gif


http://www.spc.noaa.gov/products/md/mcd2049.gif

[BeauDodson]

Evening radar from WeatherTap

http://www.beaudodson.com/images/October07/october22007eveningradar.gif

[Nate-Gillson]

Uh oh!

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 600 PM CDT FOR SOUTHERN MARION...NORTHERN RALLS AND NORTHEASTERN MONROE COUNTIES...

AT 501 PM CDT...LOCAL LAW ENFORCEMENT REPORTED A TORNADO JUST NORTH OF HUNNEWELL. THIS TORNADO WAS LOCATED 6 MILES NORTHWEST OF INDIAN CREEK...OR ABOUT 6 MILES WEST OF MONROE CITY...MOVING EAST AT 40 MPH. THIS TORNADO HAS DESTROYED A HOME 4 MILES WEST OF NORFOLK. THIS IS A VERY DANGEROUS STORM...TAKE SHELTER NOW!

LOCATIONS NEAR THE PATH OF THE TORNADO INCLUDE...RENSSELAER... SPAULDING...PALMYRA...HANNIBAL...ILASCO AND SAVERTON.