June 10-12th Plains/MW/GL/OV Severe Weather, SPC Risk Level - Day 1 Slight - Forecasts & OBS Options

[SEMIweather]

SPC has a slight risk up for portions of the Tri-States area (IA/IL/MO) on Friday, with the threat likely continuing into Saturday as the low pressure moves NE into Lower MI.

[snowlover2]

New day 1 - only the Plains threat should be discussed here.


Tornado


Hail


Wind

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1244 AM CDT THU JUN 09 2011

VALID 091200Z - 101200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL PLAINS TO NEW
ENGLAND...

...MID MS VALLEY/CNTRL PLAINS...

EARLY MORNING WATER VAPOR IMAGERY CLEARLY DEPICTS A SHORTWAVE TROUGH
OVER THE GREAT BASIN...EXTENDING INTO NRN AZ...LIFTING NEWD INTO THE
CNTRL ROCKIES...IN LINE WITH LATE EVENING MODEL GUIDANCE. THIS
FEATURE IS PROGGED TO FLATTEN THE UPPER RIDGE OVER THE CNTRL PLAINS
WITH MID LEVEL HEIGHT FALLS EXPECTED TO EXTEND NO FARTHER SOUTH THAN
I-70 ACROSS KS PRIOR TO CONVECTIVE INITIATION DURING THE LATE
AFTERNOON HOURS.

BOTH THE NAM AND GFS SUGGEST A 45-50KT H5 SPEED MAX WILL EJECT
ACROSS NERN NM AT 12Z INTO SERN NEB/SWRN IA BY 10/00Z. THIS FEATURE
WILL UNDOUBTEDLY ENHANCE THE DEEP LAYER SHEAR NECESSARY FOR
SUSTAINED LONGER LIVED SUPERCELL DEVELOPMENT NEAR A WELL DEFINED
FRONTAL ZONE THAT WILL BE DRAPED FROM NERN KS INTO SRN IA/NRN MO.
STRONG LOW LEVEL HEATING ACROSS KS WILL ENSURE DEEP BOUNDARY LAYER
THERMALS BY MID AFTERNOON ACROSS KS WHICH SHOULD EVENTUALLY MATURE
INTO SUPERCELL ACTIVITY OVER NERN KS AFTER 21Z WHERE FAVORABLE SHEAR
PROFILES WILL EXIST FOR AT LEAST A THREAT OF ISOLATED TORNADOES
WITHIN BACKED LOW LEVEL FLOW NEAR THE AFOREMENTIONED BOUNDARY.
ADDITIONALLY...VERY STEEP LAPSE RATES AND SBCAPE IN EXCESS OF 3000
J/KG WILL PROVE FAVORABLE FOR VERY LARGE HAIL...POSSIBLY IN EXCESS
OF 2 INCHES. AS A RESULT A REGIONAL POCKET OF ENHANCED CONVECTION
WILL LIKELY EVOLVE FROM NERN KS/SERN NEB INTO NWRN MO/SWRN IA AS LLJ
INCREASES DURING THE EVENING HOURS. IN ALL LIKELIHOOD ONE OR MORE
MCSS SHOULD DEVELOP ACROSS THIS REGION DURING THE LATTER HALF OF THE
PERIOD.

FARTHER SOUTH...SFC TEMPERATURES WILL ONCE AGAIN SOAR ABOVE 100F
ALONG THE DRYLINE ACROSS SCNTRL KS/NWRN OK INTO NWRN TX. THIS WILL
RESULT IN A VERY DEEP BOUNDARY LAYER THAT SHOULD FAVOR HIGH BASED
THUNDERSTORMS CAPABLE OF PRODUCING AT LEAST ISOLATED SEVERE
DOWNBURSTS OR PERHAPS EVEN SOME HAIL.

[snowlover2]

New day 2

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1258 AM CDT THU JUN 09 2011

VALID 101200Z - 111200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS ERN KS TO SRN LOWER
MI...

...SYNOPSIS...
PROGRESSIVE UPPER-AIR PATTERN FCST ACROSS NRN 1/2-2/3 OF CONUS
THROUGH PERIOD...N AND W OF RIDGING ALOFT THAT WILL EXTEND FROM NRN
MEX ACROSS SRN APPALACHIANS. MID-UPPER CYCLONE NOW OVER WRN ID
BORDER IS FCST TO PIVOT EWD ACROSS NRN ROCKIES DAY-1...CROSSING NRN
PLAINS AND NEB DURING DAYLIGHT HOURS DAY-2...THEN ACROSS UPPER MS
VALLEY AND NRN MN/LS REGION OVERNIGHT. MEANWHILE...TROUGHING OVER
PAC COAST STATES WILL BE REINFORCED BY SERIES OF SHORTWAVES NOW
MOVING EWD ACROSS NERN PAC JUST S OF GULF OF AK. IN SRN
STREAM...TROUGH NOW MOVING OVER 4-CORNERS REGION IS FCST TO
DEAMPLIFY CONSIDERABLY AS IT EJECTS NEWD DAY-1...WITH WEAK REMNANTS
MOVING THROUGH BROADER-SCALE RIDGING OVER LOWER MI AND LOWER GREAT
LAKES DAY-2. UPSTREAM WAVE OFFSHORE NRN BAJA WILL MOVE MORE SLOWLY
ENEWD...WEAKENING AND REACHING ERN NM AROUND END OF PERIOD.

SFC COLD FRONT -- NOW EXTENDING FROM SRN ONT TO LOWER MI TO
CENTRAL/SWRN KS -- IS EXPECTED TO MOVE SEWD TO PA/OH THROUGH EARLY
DAY-2 AND STALL THERE...WHILE RETREATING NWD AS WARM FRONT ACROSS
NRN INDIANA. BY 11/00Z...EXPECT FRONTAL-WAVE LOW INDUCED BY NRN
PLAINS SHORTWAVE TROUGH TO BE LOCATED OVER SERN IA/NWRN IL
REGION...WARM FRONT EWD OVER MI/INDIANA BORDER REGION...COLD FRONT
WSWWD ACROSS SERN KS AND NRN/WRN OK TO ERN PORTIONS TX PANHANDLE.
DRYLINE SHOULD INTERACT FRONT OVER S-CENTRAL KS OR NRN
OK...EXTENDING SSWWD OVER WRN OK AND W-CENTRAL TX. SFC LOW SHOULD
LIFT NEWD ACROSS PORTIONS SRN LM/WRN LOWER MI BY 11/12Z. EFFECTIVE
FRONTAL POSITION MAY BE SHUNTED SOMEWHAT FARTHER S ALMOST ANYWHERE
FROM OK TO MI BY CONVECTIVE PROCESSES.

...LOWER GREAT LAKES TO SRN PLAINS...
MCS MAY CARRY OVER FROM DAY-1 PERIOD OVER PORTIONS IA...MOVING EWD
TO ENEWD ACROSS LM AREA TO LOWER MI DURING DAY. WHILE SUCH ACTIVITY
MAY REMAIN PRIMARILY N OF SFC WARM FRONT. HOWEVER...ANY NEARLY
SFC-BASED CONVECTION MAINTAINED OR REDEVELOPING DURING DAY ALSO
WOULD HAVE POTENTIAL FOR SVR GUSTS AND HAIL.

SECOND ROUND OF SCATTERED TSTMS SHOULD DEVELOP INVOF SFC FRONTAL
ZONE DURING AFTERNOON...CENTERED ON CORRIDOR FROM ERN KS ACROSS NRN
MO TO SERN IA/NRN IL. DAMAGING WIND AND OCNL HAIL ARE MAIN
CONCERNS. WARM-SECTOR WILL BE CHARACTERIZED BY VERY RICH
BOUNDARY-LAYER MOISTURE AND STG PRE-STORM DIABATIC
HEATING...RESULTING IN MLCAPE 2500-4000 J/KG. FCST SOUNDINGS
SUGGEST LOW-LEVEL WINDS AND SHEAR WILL BE RATHER WEAK
DIURNALLY...WITH CURVED BUT SMALL HODOGRAPHS. PRESENCE OF MRGL
DEEP-LAYER SHEAR MAY SUPPORT TRANSIENT/HEAVY-PRECIP SUPERCELLS...BUT
GIVEN ALIGNMENT OF SLOW-MOVING FRONT WITH DEEP-LAYER MEAN
FLOW...MULTICELL BANDS/CLUSTERS SHOULD DOMINATE. MORE DENSE
CONCENTRATION OF SVR THREAT MAY EXIST IN THIS SWATH...BUT
UNCERTAINTIES REGARDING FRONTAL POSITION AND TIMING OF STORM MODE
PRECLUDE SUCH CORRIDOR FROM BEING DRAWN ATTM.

CONVECTION SHOULD BECOME MORE WIDELY SCATTERED SWWD ALONG FRONT AND
ISOLATED ALONG DRYLINE. HIGHER CLOUD BASES ATOP PROGRESSIVELY
DEEPER/HOTTER/WELL-MIXED BOUNDARY LAYER WILL SUPPORT POTENTIAL FOR
DAMAGING GUSTS FROM SOME OF THIS ACTIVITY. OVERALL SVR THREAT
SHOULD WANE NOCTURNALLY...FIRST NEAR DRYLINE IN EARLY EVENING AND
THROUGH OVERNIGHT HOURS NEAR FRONT.



...SERN CO/NERN NM REGION...
A FEW TSTMS MAY FORM OVER HIGHER TERRAIN AND MOVE EWD TO SEWD...IN
ENVIRONMENT OF FAVORABLE DEEP-LAYER SHEAR FOR SUPERCELLS BUT ALSO
LIMITED LOW-LEVEL MOISTURE. ANY ACCOMPANYING SVR THREAT SHOULD BE
ISOLATED AND RELATIVELY SHORT-LIVED DURING AFTERNOON INTO EARLY
EVENING.

[snowlover2]

New day 3

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0220 AM CDT THU JUN 09 2011

VALID 111200Z - 121200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS OH/PA..MID-UPPER OH
VALLEY REGION...

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS OK TO SERN CO/SWRN
KS...

...SYNOPSIS...
IN MID-UPPER LEVELS...SYNOPTIC PATTERN SHOULD LESSEN IN
AMPLITUDE...WITH WEAK MEAN TROUGHING STILL PRESENT OVER WRN CONUS
AND RIDGING FROM NRN MEX ENEWD TO SRN APPALACHIANS. MID-UPPER
CYCLONE NOW OVER ID IS FCST TO START DAY-3 OVER NERN MN/LS/NWRN ONT
AREA...MOVING EWD ACROSS REMAINDER NRN ONT THROUGH END OF PERIOD.
ACCOMPANYING CYCLONIC FLOW AND 500-MB HEIGHT FALLS SHOULD EXTEND SWD
ACROSS UPPER GREAT LAKES TO MID/UPPER OH VALLEY. MEANWHILE...SERIES
OF LOWER-AMPLITUDE SHORTWAVES WILL PASS THROUGH AND MAINTAIN BROADER
REGIME OF TROUGHING FROM NRN ROCKIES TO CA.

AT SFC...FRONTAL-WAVE LOW SHOULD LIFT NEWD FROM LOWER MI TO NECK OF
ONT BY 12/00Z...WITH COLD FRONT SWWD OVER OH/KY/AR. WRN SEGMENT OF
THIS BOUNDARY SHOULD STALL THEN RETREAT NWD AS WARM FRONT ACROSS
PORTIONS CENTRAL/SRN OK...TX PANHANDLE AND NERN NM/SERN CO. WARM
FRONT IS FCST FROM ONT LOW SEWD ACROSS PORTIONS ERN NY AND
CENTRAL/ERN PA BY 12/00Z.

...OH/PA..MID-UPPER OH VALLEY REGION...
SCATTERED TSTMS SHOULD DEVELOP ALONG/AHEAD OF SFC COLD FRONT FROM
LATE MORNING THROUGH AFTERNOON...MOVING EWD ACROSS REGION WITH
PRIMARY THREAT BEING DAMAGING GUSTS. RELATIVELY BACKED SFC FLOW
INVOF WARM FRONT ALSO WILL LEAD TO ENHANCED LOW-LEVEL HODOGRAPHS/SRH
AND STORM-RELATIVE BOUNDARY-LAYER WINDS IN THAT AREA. AS SUCH...ANY
RELATIVELY DISCRETE CONVECTION MAY BECOME SUPERCELLULAR OVER
PORTIONS PA. DEEP-LAYER FLOW WILL BE MORE UNIDIRECTIONAL FARTHER SW
OVER OH VALLEY...WITH MULTICELL BANDS/CLUSTERS POSSIBLE. AIR MASS
FROM WARM FRONT SWWD WILL BE CHARACTERIZED BY RICH LOW-LEVEL
MOISTURE...WITH SFC DEW POINTS MID 60S TO NEAR 70 F. RELATIVE MIN
IN ORGANIZED SVR POTENTIAL IS EXPECTED FARTHER SW OVER
MID-SOUTH/OZARKS REGION GIVEN RELATIVE WEAKNESS IN FLOW AT ALL
LEVELS...THOUGH LARGE CAPE SHOULD SUPPORT AT LEAST ISOLATED DAMAGING
DOWNBURST RISK.

...SRN PLAINS TO SERN CO...
WIDELY SCATTERED TO SCATTERED TSTMS SHOULD DEVELOP MAINLY N OF SFC
FRONT AS STG DIABATIC HEATING WEAKENS CINH...IN ENVIRONMENT OF
FAVORABLE MOISTURE AND FRONTAL CONVERGENCE. LARGE HAIL AND STG-SVR
GUSTS ARE EXPECTED. SOME OF THIS CONVECTION MAY PERSIST AS CLUSTERS
THROUGH EVENING HOURS...ESPECIALLY OVER PORTIONS SRN/WRN KS WHERE
35-45 KT LLJ SHOULD DEVELOP. SFC MOIST AXIS SHOULD BE N OF SFC
FRONT/WIND SHIFT FROM OK-CO...WITH SELY FLOW LEADING TO INCREASING
BOUNDARY LAYER MOISTURE THROUGHOUT DAY OVER PORTIONS SWRN KS AND ERN
CO. THIS ALSO WILL CONTRIBUTE TO ENHANCED DIRECTIONAL/DEEP-LAYER
SHEAR N OF FRONT. WEAK SFC WINDS MAY WILL LIMIT 0-1 KM SHEAR/SRH
OVER MUCH OF THIS AREA. HOWEVER...WITH ENHANCEMENTS ALONG
BOUNDARIES...SUPERCELLS ARE POSSIBLE.

...CENTRAL/NRN HIGH PLAINS...
BROAD AREA OF SWLY FLOW ALOFT WILL BE JUXTAPOSED WITH NARROW
CORRIDOR OF LOW-LEVEL MOISTURE SUFFICIENT TO SUPPORT WIDELY
SCATTERED AFTERNOON/EARLY EVENING TSTMS. FCST SOUNDINGS SUGGEST
POTENTIAL FOR SOME OF THIS ACTIVITY TO ACHIEVE AT LEAST BRIEF
SUPERCELL ORGANIZATION...THOUGH LACK OF MORE ROBUST MOISTURE SHOULD
LIMIT COVERAGE/DURATION OF THREAT. ISOLATED LARGE HAIL AND/OR
DAMAGING GUSTS ARE POSSIBLE.

[snowlover2]

Start date should be changed to the 9th for todays plains threat.

[forpetessake]

Is this the making of a derecho?

http://www.intellicast.com/National/Radar/...mp;animate=true

This post has been edited by forpetessake: Jun 9 2011, 01:37 PM

[The Snowman]

Interesting. I didn't know there was a river that slices through Madison and Canada at the same time

Attached image(s)

 

[Illinois blizzar...]

Interesting. I didn't know there was a river that slices through Madison and Canada at the same time

We learn new things everyday

This post has been edited by Illinois blizzard: Jun 9 2011, 02:09 PM

[snowlover2]

Updated day 2

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT THU JUN 09 2011

VALID 101200Z - 111200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LOWER MO
VALLEY/MIDWEST/GREAT LAKES REGION...

...SYNOPSIS...
A PROGRESSIVE UPPER FLOW PATTERN WILL PERSIST ACROSS THE MAJORITY OF
THE CONUS INTO FRIDAY...WITH THE RELATIVELY STRONGER WESTERLIES
RELEGATED TO THE WESTERN/NORTHERN HALVES OF THE CONUS ON THE
PERIPHERY OF AN UPPER RIDGE FROM MEXICO TO THE CENTRAL/SOUTHERN
APPALACHIANS. A SHORTWAVE TROUGH OVER THE NORTHERN ROCKIES THURSDAY
AFTERNOON IS EXPECTED TO CROSS THE NORTHERN PLAINS ON FRIDAY...AND
REACH THE UPPER MS VALLEY/LAKE SUPERIOR VICINITY BY EARLY SATURDAY.
A COLD FRONT...AUGMENTED BY CONVECTIVE PROCESSES/OUTFLOW...WILL
SHIFT EAST-SOUTHEASTWARD ON FRIDAY ACROSS THE SOUTH-CENTRAL
PLAINS/MIDWEST/MIDDLE MS VALLEY...WHILE A WARM FRONT RETURNS
NORTHWARD ACROSS THE OH VALLEY AHEAD OF A WEAK FRONTAL WAVE.

...GREAT LAKES/MIDWEST/LOWER MO VALLEY AND SOUTHERN PLAINS...
CURRENT THINKING IS THAT SCATTERED TSTMS/POTENTIAL MCS WILL BE
ONGOING ACROSS THE UPPER MS VALLEY VICINITY FRIDAY MORNING...WITH
OTHER POTENTIALLY STRONG/SEVERE ELEVATED TSTMS /AT LEAST IN ISOLATED
SENSE/ ONGOING ACROSS NORTHERN KS ATTENDANT TO THE LEADING EDGE OF
SHORTWAVE TROUGH ASSOCIATED DPVA. AS THE SHORTWAVE TROUGH/ASSOCIATED
DPVA SHIFTS GENERALLY EASTWARD OVER THE MIDWEST...AN UPSWING IN DEEP
CONVECTIVE COVERAGE/INTENSITY IS LIKELY TO OCCUR DURING THE
AFTERNOON IN VICINITY OF THE SOUTHWEST-NORTHEAST
ORIENTED/CONVECTIVELY SHUNTED COLD FRONT. THIS WILL BE IN A CORRIDOR
FROM EASTERN KS INTO CENTRAL/NORTHERN MO AND PORTIONS OF IL/INDIANA.
HERE...AT LEAST MODERATE DESTABILIZATION IS ANTICIPATED WITH
2000-3500 J/KG OF MLCAPE. WHILE MODERATELY STRONG WESTERLIES ALOFT
WILL ACCOMPANY THE AFOREMENTIONED SHORTWAVE TROUGH...THE STRONGEST
VERTICAL SHEAR WILL STILL LAG /TO THE NORTHWEST/ THE
NORTHEAST-SOUTHWEST ORIENTED FRONTAL ZONE. WHILE SOME SUPERCELLS
WILL BE POSSIBLE...MULTICELL CLUSTERS SHOULD BE DOMINANT WITH
DAMAGING WINDS AND SEVERE HAIL AS THE PRIMARY CONCERNS. VEERED/WEAK
LOW LEVEL WINDS WILL GENERALLY KEEP THE TORNADO POTENTIAL LOW ON
FRIDAY...ALTHOUGH AN ISOLATED TORNADO THREAT CANNOT BE RULED OUT FOR
AREAS SUCH AS LOWER MI AND NORTHERN PORTIONS OF INDIANA/OH AHEAD OF
THE WEAK SURFACE LOW/NEAR THE WARM FRONT.

FARTHER SOUTHWEST ACROSS THE SOUTHERN PLAINS...DEEP CONVECTION WILL
BE MORE WIDELY SCATTERED ALONG THE COLD FRONT AND IN VICINITY OF A
SURFACE TRIPLE POINT/DRYLINE...INCLUDING NORTHERN/WESTERN PORTIONS
OF OK AND NORTHWEST TX. HIGHER CLOUD BASES ATOP PROGRESSIVELY
DEEPER/HOTTER/WELL-MIXED BOUNDARY LAYER WILL SUPPORT POTENTIAL FOR
DAMAGING GUSTS FROM SOME OF THIS ACTIVITY IN ADDITION TO SOME HAIL.
THE OVERALL SEVERE THREAT SHOULD WANE NOCTURNALLY...FIRST NEAR THE
DRYLINE EARLY FRIDAY EVENING AND THE LATE EVENING/OVERNIGHT HOURS
NEAR THE COLD FRONT.



...SOUTHEAST CO/NORTHEAST NM...
A FEW TSTMS MAY FORM ALONG THE HIGHER TERRAIN AND MOVE
EAST-SOUTHEASTWARD FRIDAY AFTERNOON...IN AN ENVIRONMENT OF FAVORABLE
DEEP-LAYER SHEAR FOR SUPERCELLS BUT ALSO LIMITED LOW-LEVEL MOISTURE.
ANY ACCOMPANYING SEVERE THREAT SHOULD BE ISOLATED AND RELATIVELY
SHORT-LIVED DURING THE AFTERNOON/EARLY EVENING.

[snowlover2]

New day 1


Tornado


Hail


Wind

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1237 AM CDT FRI JUN 10 2011

VALID 101200Z - 111200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM OK...NEWD INTO THE OH
VALLEY...

...MID MS/OH VALLEY REGION...

LATEST WV IMAGERY DEPICTS A WELL DEFINED UPPER SHORT WAVE TROUGH
WITH AN APPARENT CLOSED CIRCULATION CENTERED VERY NEAR GCC IN NERN
WY. THIS FEATURE IS MOVING EWD TOWARD THE UPPER/MID MS VALLEY
REGION IN LINE WITH LATEST MODEL GUIDANCE AND SHOULD SERVE TO
ENHANCE SFC-BASED THUNDERSTORM DEVELOPMENT ALONG A PRONOUNCED FRONT
ACROSS IL/MO FAIRLY EARLY IN THE PERIOD...BY 19-20Z...AS SFC
TEMPERATURES WARM INTO THE MID-UPPER 80S. IN FACT...MULTIPLE
THUNDERSTORM CLUSTERS WILL LIKELY BE ONGOING AT THE BEGINNING OF THE
PERIOD WITHIN THE WARM ADVECTION ZONE ACROSS IA INTO WI ALONG NOSE
OF LLJ. THIS ACTIVITY SHOULD PROPAGATE EWD INTO LOWER MI LATER IN
THE DAY REINFORCING AN ATTENDANT WARM FRONT THAT SHOULD RELUCTANTLY
RETREAT INTO SRN LOWER MI AFTER 21Z. ALTHOUGH THE STRONGEST DEEP
LAYER SHEAR WILL REMAIN WITHIN THE POST FRONTAL AIRMASS BENEATH THE
MID LEVEL JET...IT APPEARS SUFFICIENT DEEP LAYER SHEAR WILL
OVERSPREAD THE WARM SECTOR ACROSS THE MID MS/OH VALLEY REGION FOR
ORGANIZED MULTI-CELL THUNDERSTORM CLUSTERS AND PERHAPS EVEN WEAK
SUPERCELLS NEAR THE WARM FRONT. FOR THIS REASON IT WOULD SEEM
REASONABLE THAT LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY
SEVERE THREATS WITH CONVECTION THAT EVOLVES WITHIN A MODERATELY
UNSTABLE ENVIRONMENT AHEAD OF ADVANCING COLD FRONT.

...SRN PLAINS...

FARTHER SOUTH ACROSS THE PLAINS OF OK/NWRN TX STRONG HEATING WILL
ONCE AGAIN ALLOW SFC TEMPERATURES TO SOAR TO NEAR 100F IN ADVANCE OF
WIND SHIFT. SUCH STRONG HEATING WILL INDUCE DEEP THERMALS AS LAPSE
RATES STEEPEN AND INHIBITION SHOULD BE NEGLIGIBLE BY 22-23Z ALLOWING
FOR SCATTERED THUNDERSTORM DEVELOPMENT. WITH BASES EXPECTED TO BE
NEAR 700MB AND SFC TEMP/DEW POINT SPREADS POSSIBLY APPROACHING
40-50F...STRONG DOWNBURSTS ARE POSSIBLE DUE TO DRY SUB-CLOUD LAYER.

...ELSEWHERE...

SCATTERED THUNDERSTORMS WILL ONCE AGAIN DEVELOP ALONG A CORRIDOR
FROM THE CNTRL GULF STATES OF MS/AL...NEWD ACROSS THE SRN
APPALACHIANS INTO THE MIDDLE ATLANTIC DUE PRIMARILY TO STRONG
BOUNDARY LAYER HEATING. WEAK SHEAR WILL SUPPORT PRIMARILY
PULSE-TYPE UPDRAFTS CAPABLE OF PRODUCING LOCALLY DAMAGING WINDS AND
PERHAPS EVEN HAIL. THIS ACTIVITY WILL BE DIURNALLY DRIVEN AND
SHOULD WEAKEN QUICKLY WITH LOSS OF HEATING.

[WeatherMonger]

Be interesting to see what if any changes go into the new Day 1 in about 30 minutes or so. ILX saying the low is going to track further south than originally expected

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
944 AM CDT FRI JUN 10 2011

.DISCUSSION...
ISSUED 944 AM CDT FRI JUN 10 2011

MORNING SURFACE ANALYSIS SHOWS STATIONARY FRONTAL BOUNDARY
EXTENDING FROM DANVILLE W/SW TO JUST NORTH OF SAINT LOUIS. STRONG
TEMPERATURE GRADIENT EXISTS ACROSS THIS BOUNDARY...WITH READINGS
HOVERING IN THE UPPER 50S AND LOWER 60S TO THE NORTH...WHILE
SOARING INTO THE MIDDLE 80S FAR SOUTHEAST. WEAK AREA OF LOW
PRESSURE IS STILL EXPECTED TO DEVELOP ALONG THE FRONT THIS
AFTERNOON...HOWEVER LATEST MODEL GUIDANCE NOW SUGGESTS LOW WILL
TRACK RIGHT ACROSS CENTRAL ILLINOIS INSTEAD OF TO THE NORTH AS
PREVIOUSLY THOUGHT. THIS WOULD TEND TO KEEP THE FAR NORTHERN KILX
CWA ON THE COOL SIDE OF THE FRONT THROUGHOUT THE DAY. AS A
RESULT...HAVE ADJUSTED AFTERNOON HIGHS TO FEATURE UPPER 70S ACROSS
THE NORTHERN TIER OF COUNTIES. FURTHER SOUTH...HAVE MAINTAINED
UPPER 80S/LOWER 90S ACROSS THE MAJORITY OF THE AREA...WITH MIDDLE
90S SOUTH OF I-70. IN ADDITION TO THE MAIN SYNOPTIC FRONT...NUMEROUS
MESOSCALE BOUNDARIES ARE PRESENT AROUND CENTRAL ILLINOIS...AS WELL
AS A WELL-DEFINED MCV JUST N/NW OF SAINT LOUIS. SUBSIDENCE IN THE
WAKE OF A WAVE NOW PUSHING ACROSS NORTHERN INDIANA HAS LED TO A
LULL IN THE PRECIP THIS MORNING...HOWEVER INCREASING LIFT
ASSOCIATED WITH THE MCV AND APPROACHING SURFACE LOW WILL LEAD TO
THUNDERSTORM DEVELOPMENT ALONG THE FRONT AND OUTFLOW BOUNDARIES
THIS AFTERNOON AND EVENING. HAVE ADJUSTED POPS TO GO MAINLY DRY
THROUGH THE REMAINDER OF THE MORNING...WITH HIGH CHANCE TO LIKELY
POPS THIS AFTERNOON. SEVERE WEATHER IS STILL A GOOD POSSIBILITY LATER
TODAY...WITH THE MAIN THREATS BEING LARGE HAIL AND DAMAGING WINDS.



BARNES

[snowlover2]

Had one heck of a storm this morning around 6:30ish. Unbelievably loud thunder and lightning strikes that sounded like they were hitting right outside my window.

[snowlover2]

Updated day 1


Tornado


Hail


Wind

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1129 AM CDT FRI JUN 10 2011

VALID 101630Z - 111200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT
FROM THE SRN PLAINS TO THE OH VALLEY...

...MO/IL/INDIANA/OH THIS AFTERNOON/EVENING...
A MIDLEVEL SHORTWAVE TROUGH OVER CENTRAL SD THIS MORNING WILL
PROGRESS EWD TO WI BY LATE TONIGHT. AN ASSOCIATED SURFACE CYCLONE
IS EXPECTED TO DEVELOP ALONG A STALLED FRONT NEAR THE MO/IA/IL
BORDER THIS AFTERNOON AND MOVE ENEWD TO SRN LOWER MI OVERNIGHT. ON
THE MESOSCALE...THE SURFACE FRONT HAS BEEN REINFORCED BY CONVECTIVE
OUTFLOWS ACROSS CENTRAL/SW OH...CENTRAL/NRN INDIANA...AND CENTRAL
IL. THE STRONGEST SURFACE HEATING IS ONGOING SOUTH OF THE COMPOSITE
FRONT/OUTFLOW BOUNDARY...WHERE AFTERNOON MLCAPE WILL INCREASE TO
2000-2500 J/KG AND CONVECTIVE INHIBITION WILL BE REMOVED BY EARLY
AFTERNOON WHEN NEW THUNDERSTORM DEVELOPMENT IS EXPECTED. THIS SAME
CORRIDOR WILL BE ALONG THE SRN FRINGE OF THE STRONGER /30-40 KT/
MIDLEVEL FLOW...WHICH WILL CONTRIBUTE TO THE POTENTIAL FOR ORGANIZED
CLUSTERS CAPABLE OF PRODUCING DAMAGING WINDS AND LARGE HAIL. A
MARGINAL SUPERCELL/TORNADO THREAT WILL BE FOCUSED ALONG THE
RETREATING OUTFLOW BOUNDARY ACROSS NRN INDIANA WHERE LOW-LEVEL AND
DEEP-LAYER SHEAR ARE STRONGEST.

...SE KS/NRN AND WRN OK/NW TX THIS AFTERNOON THROUGH TONIGHT...
A BELT OF ELEVATED CONVECTION FROM CENTRAL OK NEWD INTO SE KS/WRN MO
IS EXPECTED TO SLOWLY DIMINISH THROUGH MIDDAY AS WAA AND THE LLJ
WEAKEN GRADUALLY. CLEARING IN THE WAKE OF THE MORNING CONVECTION
WILL ALLOW SURFACE HEATING/DESTABILIZATION ALONG THE SURFACE FRONT
LATER THIS AFTERNOON/EVENING FROM SE KS SWWD INTO N CENTRAL
OK...WHILE CLEAR SKIES AND STRONG SURFACE HEATING WILL CONTINUE FROM
WRN OK INTO NW TX. A SERIES OF WEAK MIDLEVEL VORTICITY MAXIMA FROM
CENTRAL NM NEWD INTO WRN KS WILL DRIFT ENEWD INVOF THE STALLED FRONT
AND COMBINE WITH THE DAYTIME HEATING TO SUPPORT ISOLATED
THUNDERSTORM DEVELOPMENT IN OK/KS.

FARTHER SW...DEEP MIXING AND RESIDUAL BOUNDARY LAYER DEWPOINTS IN
THE 50S WILL SUPPORT STORM DEVELOPMENT ALONG THE FRONT IN NW TX THIS
EVENING. VERTICAL SHEAR AND THERMODYNAMIC PROFILES WILL FAVOR
ORGANIZED CLUSTERS WITH SOME HIGH-BASED SUPERCELL POTENTIAL EARLY IN
THE DEVELOPMENT...WITH AN ATTENDANT RISK FOR DAMAGING WINDS AND
LARGE HAIL. THIS CONVECTION SHOULD SPREAD NEWD ALONG THE FRONT INTO
SW OK BY EARLY TONIGHT...SUPPORTED BY A NOCTURNAL INCREASE IN THE
LLJ AND WAA.

[Snow____]

Lmao @ me being wedge in between 2 storms and likely missing both of them lol.. comedy.

[The Snowman]

Kind of strange that the NWS forecasted my high at 73 and right now it's 63... they also missed a 70? percent chance for 'heavy rain' today.

I hope it means it won't rain tonight, I don't want my bonfire to be rained on...

[WeatherMonger]

I love the look of the 16Z HRRR at 7pm tonight IMBY

[Illinois blizzar...]

Changes from the SPC update.
TOR-

HAIL-

WIND-

[WeatherMonger]

Newest outlook got rid of 30% hail altogether and a good chunk of the western portion of 30% wind.

[TJ Schulte]

Very concerned currently for NE Indiana/NW Ohio for tonight. Current SRH values are expanding to 300 with anywhere from 45-55 kts of bulk shear and now the sun is out in full force temperatures are rising as well as CAPE which should be able to hit 3000 j/kg across the area later today. The vis sat is showing a lot of stuff starting to rise especially that cu field right overhead. Also EHI's are now at 2 in some parts and that is also growing. I'm tellin you guys a few more hours of sun and things could get very bad

[WeatherMonger]

only 2 18Z soundings done today.

ILX


ILN