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NL

Severe Weather Us Oct 09'

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The SPC at the NWS have issued a slight risk of severe weather affecting a large area from SW Texsas through to lower Ohio valley with a 5- 10% chance of a tornado in and around the Ozarks,( ENE Oklahoma 5%, N Arkansas, SE Missouri and later into S Illinois).Storms will be fast moving especially late afternoon evening around S Ohio valley,

Tornado probabilities.

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1129 AM CDT THU OCT 08 2009

VALID 081630Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS INTO THE

MID SOUTH/LOWER OH RIVER VALLEY...

...SYNOPSIS...

OVERALL SETUP REMAINS QUITE MESSY THROUGH THE PERIOD AS

POSITIVELY-TILTED MID/UPPER LEVEL TROUGH EJECTS ACROSS THE SRN

ROCKIES AS IT PHASES WITH AMPLIFYING NRN STREAM IMPULSE DIGGING INTO

THE NRN HIGH PLAINS. THIS WILL AMPLIFY BROAD SWLY FLOW ALOFT ATOP

UNSEASONABLY MOIST BOUNDARY LAYER AIR MASS SPREADING NNEWD AWAY FROM

THE SRN PLAINS AND ACROSS THE LOWER/MID MS RIVER VALLEY. IN

ADDITION...LOW AMPLITUDE IMPULSES WITHIN THE SRN STREAM SHOULD

PROVIDE CONCENTRATIONS OF TSTM ACTIVITY THROUGH THE PERIOD. PRIMARY

SURFACE COLD FRONT NOW ADVANCING OUT OF THE CENTRAL HIGH

PLAINS/UPPER MS RIVER VALLEY WILL CONTINUE PUSHING SEWD THROUGH THE

PERIOD...WITH PRECEDING SURFACE FRONT INTO AR/TN VALLEY EXPECTED TO

ERODE AS BROAD WARM SECTOR EVOLVES WITH NWRN PORTION OF THE BOUNDARY

ALLOWING WEAK LOW CENTER TO DEVELOP INVOF THE OZARK REGION THIS

AFTERNOON. THIS LOW SHOULD TRACK NEWD ALONG THE OH RIVER VALLEY

OVERNIGHT.

...TX INTO THE OZARK REGION...

MODEST HEATING IS EXPECTED INTO WRN/CENTRAL TX AND SHOULD ALLOW

LARGE AREA OF MODERATE INSTABILITY TO DEVELOP SOUTH OF THE RED

RIVER...WITH LOW CLOUDS/PRECIPITATION LIMITING HEATING/INSTABILITY

INTO CENTRAL/ERN OK AND WRN AR TODAY. REGARDLESS SUFFICIENT

WEAKENING OF THE CAP OVER TX AND INCREASING CONVERGENCE FARTHER NNE

WILL ALLOW INCREASING TSTMS FROM WRN TX INTO CENTRAL/NERN OK AND THE

OZARKS THROUGH THE AFTERNOON. ACTIVITY WILL BECOME WIDESPREAD BY

LATE IN THE DAY/EVENING AND EVENTUALLY CONSOLIDATE INTO A LARGE

LINEAR MCS ADVANCING STEADILY SEWD OVERNIGHT AS DEEP CONVERGENCE

BECOMES INCREASINGLY PARALLEL TO THE FLOW ALOFT. DEEP LAYER SHEAR

REMAINS QUITE STRONG AND WILL SUPPORT MULTIPLE CONVECTIVE

MODES...INCLUDING SUPERCELLS. DAMAGING WINDS WILL BE PRIMARY SEVERE

THREAT...ALTHOUGH ISOLATED LARGE HAIL AND A TORNADO OR TWO REMAIN

POSSIBLE...WITH MORE WIDESPREAD THREAT OF VERY HEAVY RAINFALL.

...OZARKS NEWD INTO THE OH RIVER VALLEY...

POTENT HODOGRAPHS WILL EVOLVE NEWD INVOF TRANSIENT SURFACE LOW AND

50+ KT LLJ EXPECTED TO SHIFT ACROSS THE MID SOUTH AND NEWD UP THE OH

RIVER VALLEY OVERNIGHT. INFLUX OF RICH GULF MOISTURE IS EXPECTED TO

SURGE NEWD INTO THE MID SOUTH/LOWER OH RIVER VALLEY BY LATE

TODAY...ALTHOUGH SPEED OF SYSTEM MAY OUTRUN MOIST AXIS WITH NE

EXTENT LATER TONIGHT. APPEARS PRIMARY COLLOCATION OF MODEST

MLCAPE...WEAKENING CAP...AND ENHANCED SHEAR SHOULD SUPPORT RELATIVE

MAX IN TORNADO POTENTIAL TOWARDS THE MID SOUTH/LOWER OH RIVER VALLEY

INTO THE EVENING...ALONG WITH DAMAGING WIND THREAT FROM FAST MOVING

STORMS /FORECAST MOTIONS AROUND 45 KT/. ALTHOUGH STILL SOME

QUESTION REGARDING EVENTUAL STORM-MODE AS ACTIVITY MAY TEND TO

EVOLVE IN THE FORM OF SMALL LINES/BOW ECHOES THROUGH THE

EVENING/OVERNIGHT AHEAD OF STRONG SEWD MOVING COLD FRONT...AND

TENDENCY FOR SEWD MOVING SURFACE COLD AIR TO UNDERCUT NEWD MOVING

CELLS. SHOULD A STORM PERSIST WITH FEED OF RICH WARM SECTOR

AIR...CONDITIONAL THREAT OF A SIGNIFICANT TORNADO AND/OR WIND DAMAGE

WILL REMAIN.

..EVANS/GRAMS.. 10/08/2009

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Tornado warning has been issued for Sterling County, Texas.

BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE SAN ANGELO TX

619 PM CDT THU OCT 8 2009

THE NATIONAL WEATHER SERVICE IN SAN ANGELO HAS ISSUED A

* TORNADO WARNING FOR...

STERLING COUNTY IN WEST CENTRAL TEXAS...

* UNTIL 700 PM CDT

* AT 617 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A

SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 14 MILES WEST OF

STERLING CITY...MOVING NORTHEAST AT 35 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...

STERLING CITY BY 640 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING

GOLFBALL SIZE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS IN EXCESS OF

70 MPH.

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Looking lively in parts of Texas this evening with a few Tornado warnings issued.

Meso discussion for tornado watch just issued for N Texas S and E Oklahoma and far NW Arkansas.

MESOSCALE DISCUSSION 2085

NWS STORM PREDICTION CENTER NORMAN OK

0659 PM CDT THU OCT 08 2009

AREAS AFFECTED...NORTH TX...SRN AND ERN OK...FAR NW AR

CONCERNING...TORNADO WATCH 759...

VALID 082359Z - 090100Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 759 CONTINUES.

A THREAT FOR HEAVY RAINFALL AND ISOLATED SEVERE STORMS WILL LIKELY

CONTINUE THROUGH LATE EVENING FROM NORTH TX NEWD ACROSS SRN AND ERN

OK INTO FAR NW AR. HAIL...ISOLATED DAMAGING WIND GUSTS AND HEAVY

RAINFALL WILL BE POSSIBLE WITH THE STRONGER RAINBANDS AND MORE

INTENSE CELL ELEMENTS.

23Z SFC ANALYSIS SHOWS A COLD FRONT EXTENDING NEWD FROM SW OK INTO

SW MO WITH A WARM FRONT INTERSECTING THE COLD FRONT NEAR A SFC LOW

IN THE OKLAHOMA CITY AREA. GPS-WX PRECIPITABLE WATER VALUES ARE

AROUND 2 INCHES IN CNTRL OK WITH SFC DEWPOINTS IN THE 70 TO 75 F

RANGE. THIS MOIST ENVIRONMENT WILL BE VERY FAVORABLE FOR HEAVY

RAINFALL AS RAINBANDS AND TRAINING CELLS MOVE OVER THE SAME AREAS.

RAINFALL OF UP TO 2 INCHES PER HOUR WILL BE POSSIBLE ACROSS PARTS OF

THE MCD AREA.

IN ADDITION...THE RUC IS ESTIMATING THAT MODERATE INSTABILITY IS

PRESENT ACROSS MUCH OF THE WARM SECTOR JUST TO THE SOUTHEAST OF THE

BRAND BAND OF CONVECTION. THIS COMBINED WITH STRENGTHENING LOW-LEVEL

FLOW AT 55-65 KT OF VERTICAL SHEAR WILL BE FAVORABLE FOR ORGANIZED

STORMS AND A FEW SUPERCELLS. ROTATING STORMS WILL BE CAPABLE OF

PRODUCING ISOLATED HAIL. HOWEVER...THE THREAT FOR TORNADOES AND

DAMAGING WIND GUSTS MAY INCREASE THIS EVENING INTO ERN OK AND NW AR

AS THE LOW-LEVEL JET BROADENS. THIS WILL BE ESPECIALLY TRUE IF

SUPERCELLS CAN PERSIST AND A LARGE-SCALE BOWING LINE-SEGMENT CAN

ORGANIZE.

..BROYLES.. 10/08/2009

Latest satellite image.

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Although the dynamics were fine for tornadoes yesterday there has been no reports of touchdowns but reports of large hail (up to 1¾") and

damaging straight-line winds 60+mph have been recieved , one stating a barn 52ft x 32ft was blown away in Hardin County, Kentucky.

Today the SPC have issued a slight risk again but mainly for heavy rain and damaging wind gusts.

http://www.spc.noaa.gov/products/

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Yes NL

After a relatively dreadful May and Chase Season 09 it looks like the Fall Season is failing to produce any notable Outbreaks thus far. Some of the Texas Storms had nice Hook echoes last night but they all looked like Big Hail Producers with a 5" Report being received over on ST!

Roll on 2010 - These things have a certain way of balancing out :rolleyes:

Paul S

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