April 24-26 MW/OV Severe Weather, SPC Risk Level: Day 1 Slight Risk Forecasts and OBS Options

[WeatherMonger]

SPC has See Text out for Tuesday and Wednesday

DAY 2 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0109 AM CDT MON APR 23 2012

VALID 241200Z - 251200Z

...NO SVR TSTM AREAS FORECAST...

CORRECTED FOR NDFD GRAPHIC

...SYNOPSIS...
AN AMPLIFIED LARGE SCALE PATTERN WILL REMAIN OVER MUCH OF THE
CONUS/CANADA THROUGH TUESDAY. AN UPPER RIDGE OVER THE ROCKIES WILL
BE FLANKED BY A DEEP LONGWAVE TROUGH OVER THE EASTERN PORTIONS OF
THE CONUS/CANADA AND FAR WESTERN ATLANTIC...WHILE DUAL UPPER TROUGHS
SHIFT EASTWARD OVER THE EASTERN PACIFIC AMID SPLIT UPPER FLOW.


...UPPER MIDWEST/MIDDLE MS VALLEY/OH VALLEY...
AN ELEVATED MIXED LAYER WILL BUILD EASTWARD AND BECOME INCREASINGLY
EXTENSIVE OVER THE NORTHERN/CENTRAL PLAINS AND ADJACENT UPPER
MIDWEST THROUGH TUESDAY. APPRECIABLE MOISTURE RETURN IS UNLIKELY
THROUGH TUESDAY GIVEN PERSISTENCE OF CONTINENTAL NEAR-GULF OF MEXICO
TRAJECTORIES...BUT A DEGREE OF MOISTENING WILL NONETHELESS OCCUR
INTO THE REGION BENEATH THE STRENGTHENING CAP.

IT IS CONCEIVABLE THAT ISOLATED TO SCATTERED TSTMS COULD DEVELOP
TUESDAY AFTERNOON NEAR A SURFACE LOW AND WEAK FRONT/SURFACE TROUGH
ACROSS THE EASTERN DAKOTAS/MN. HOWEVER...A SOMEWHAT MORE CERTAIN
SCENARIO IS FOR ISOLATED TSTMS TO DEVELOP LATE TUESDAY NIGHT ACROSS
THE MIDWEST/OH VALLEY ON THE EASTERN EDGE OF THE CAP IN AREAS
NEAR/NORTHEAST OF A WARM FRONT. IT SHOULD BE NOTED THAT CONSIDERABLE
NUMERICAL GUIDANCE VARIABILITY DOES STILL EXIST /ESPECIALLY 00Z GFS
VS 00Z NAM/12Z ECMWF -- WITH THE LATTER MORE AGGRESSIVE/. BUT EVEN
WITH THIS GUIDANCE VARIABILITY AND A MARGINAL MOISTURE INFLUX ALOFT
LATE TUESDAY...WILL INTRODUCE LOW PROBABILITIES FOR
CONDITIONAL/ISOLATED HAIL POTENTIAL TUESDAY NIGHT IF/WHERE STORMS
OCCUR ACROSS THE MIDWEST/OH VALLEY...GIVEN THE PROXIMITY OF VERY
STEEP LAPSE RATES ALOFT COUPLED WITH A HIGH DEGREE OF SHEAR.

..GUYER.. 04/23/2012

Wednesday

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT MON APR 23 2012

VALID 251200Z - 261200Z

...MIDWEST/MIDDLE MS VALLEY/OH VALLEY...
NUMERICAL GUIDANCE MAY BE A BIT TOO AGGRESSIVE WITH BOUNDARY LAYER
MOISTENING INTO DAY 3/WEDNESDAY ACROSS THE REGION GIVEN
CURRENT/SHORT-TERM FLOW TRAJECTORIES VIA THE CENTRAL CONUS
ANTICYCLONE. NONETHELESS...MOISTENING WILL OCCUR NEAR A SHARPENING
WARM FRONT/ADJACENT WARM SECTOR AS A PLUME OF STEEP LAPSE RATES
ALOFT ADVECTS EASTWARD TOWARD THE MIDDLE MS VALLEY/TN VALLEY.
SPECIFIC SCENARIO CONFIDENCE IS NOT PARTICULARLY HIGH GIVEN
ANTICIPATED NEBULOUS/LOW AMPLITUDE WEST-NORTHWESTERLY FLOW ALOFT.
BUT AN ASSORTMENT OF NUMERICAL GUIDANCE IS INDICATIVE OF THE
POTENTIAL FOR ONE OR MORE PROGRESSIVE DISTURBANCES ALOFT TO COINCIDE
WITH A RELATIVELY MOIST/POTENTIALLY UNSTABLE AIRMASS IN VICINITY OF
THE AFOREMENTIONED WARM FRONT...AND ALONG/SOUTH OF A
SOUTH-SOUTHEASTWARD MOVING COLD FRONT ACROSS THE UPPER MIDWEST.
OVERALL SCENARIO APPEARS TO WARRANT LOW SEVERE PROBABILITIES FOR AT
LEAST ISOLATED OR CONDITIONAL HAIL/WIND POTENTIAL...PERHAPS EARLY
WEDNESDAY /HAIL/ BUT MORE SO WEDNESDAY AFTERNOON/NIGHT ACROSS THE
REGION.

This post has been edited by WeatherMonger: Apr 24 2012, 05:10 AM

[WeatherMonger]

The way ILX mentions it, it seems they think SPC may possibly introduce a slight risk at some point

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
330 AM CDT MON APR 23 2012

WEAK LOW PRESSURE OF 1010 MB JUST NORTH OF MONTANA TO DEEPEN SE
INTO THE CENTRAL STATES WED WITH A WARM FRONT EXTENDING EAST INTO
CENTRAL OR SW IL. HAVE SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS TUE
NIGHT. THIS TO INCREASE CHANCES OF SHOWERS AND THUNDERSTORMS WED
AND WED NIGHT WITH LIKELY CHANCES SE HALF WED NIGHT. SPC DOES NOT
HAVE A SLIGHT RISK YET BUT DO HAVE CENTRAL IL IN A 5% RISK AREA
TUE NIGHT THROUGH WED NIGHT. WED STILL APPEARS TO BE THE WARMEST
DAY WITH HIGHS IN THE 70S AND WARMEST IN SW AREAS. LINGERED A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN SE IL THU MAINLY IN
THE MORNING AS STORM SYSTEM SHIFTS SE OF IL.

[jdrenken]

I could see some elevated hailers out of this.

[jdrenken]

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1150 AM CDT MON APR 23 2012

VALID 241200Z - 251200Z

...NO SVR TSTM AREAS FORECAST...

...SERN NEB TO WRN KY...

UPPER RIDGE IS EXPECTED TO HOLD ACROSS THE ROCKIES THROUGH THE DAY2
PERIOD WITH WEAK HEIGHT RISES POSSIBLE INTO THE MID MS/TN VALLEY
REGION LATE. AS SFC HIGH SETTLES INTO THE GULF OF MEXICO SLY FLOW
SHOULD INCREASE ACROSS THE PLAINS AND A WARM FRONT SHOULD ESTABLISH
ITSELF ORIENTED ALONG AN AXIS FROM THE NEB/KS BORDER...SEWD INTO WRN
KY BY 25/00Z. THE DEVELOPING WARM FRONT SHOULD SERVE AS THE FOCUS
FOR POSSIBLE CONVECTION...PRIMARILY DURING THE LATTER HALF OF THE
PERIOD.

LATEST NAM SUGGESTS STRONG BOUNDARY LAYER HEATING WILL OCCUR ACROSS
THE PLAINS WHICH WILL ALLOW SFC TEMPERATURES TO SOAR INTO THE UPPER
80S INTO THE LOWER 90S ALONG THE PLAINS PORTION OF THE WARM FRONT
NEAR THE KS BORDER. IN FACT PFC FOR CNK AT 23Z EXHIBITS SBCAPE ON
THE ORDER OF 1300 J/KG WITH A 94/45 TEMP/DEW POINT. IF THIS TYPE OF
READING IS ATTAINED CONVECTIVE TEMPERATURE WILL BE REACHED AND HIGH
BASED CONVECTION COULD DEVELOP DURING THE LATE AFTERNOON. A SLOW
SSEWD MOVEMENT OFF THE BOUNDARY WOULD THEN BE POSSIBLE ACROSS
PORTIONS OF NERN KS. GUSTY WINDS AND PERHAPS SOME HAIL COULD BE
NOTED INTO THE EVENING HOURS.

ANOTHER ZONE WHERE TSTMS MAY DEVELOP WILL BE FARTHER EAST ACROSS THE
MID MS VALLEY WITHIN A ZONE OF INCREASING WARM ADVECTION. WNWLY
45KT LLJ IS EXPECTED TO INCREASE DURING THE OVERNIGHT HOURS AND THIS
MAY PROVIDE SUFFICIENT LIFT FOR ELEVATED CONVECTION. MARGINALLY
SEVERE HAIL COULD ACCOMPANY THE STRONGEST UPDRAFTS AS THEY SPREAD
SEWD INTO THE TN VALLEY LATE.

...NRN ROCKIES...

UPPER RIDGE MAY FLATTEN SLIGHTLY ACROSS THE NRN ROCKIES TUESDAY
AFTERNOON BUT PRIMARILY SFC-BASED HEATING WILL BE THE INSTIGATOR IN
CONVECTIVE DEVELOPMENT. LOW LEVEL MOISTURE SHOULD REMAIN SOMEWHAT
MARGINAL WITH PW VALUES EXPECTED TO ONLY RANGE FROM .50-60 INCH.
EVEN SO RELATIVELY STEEP LAPSE RATES WILL SUPPORT CONVECTIVE
DEVELOPMENT AND ANY STORMS THAT FORM ACROSS ERN ORE INTO SWRN MT
WILL DO SO WITHIN A ZONE OF MODEST DEEP LAYER SHEAR THAT COULD
SUPPORT ORGANIZED MULTI-CELL UPDRAFTS. MARGINAL SEVERE HAIL IS THE
MAIN THREAT WITH THIS ACTIVITY.

..DARROW.. 04/23/2012

[Juniorrr]

Some showers or thunderstorms in IL,MO,IN,KY


This post has been edited by Juniorrr: Apr 23 2012, 04:05 PM

[jdrenken]

4km NAM NMM holds off with the good stuff until 5am. That would stink on my way to work.

[WeatherMonger]

Slight Risk added for Wednesday

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT TUE APR 24 2012

VALID 251200Z - 261200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE
MIDWEST/OH VALLEY...

...MIDDLE/UPPER MS VALLEY AND MIDWEST/OH VALLEY...
CONCERN REMAINS THAT NUMERICAL GUIDANCE IS TOO AGGRESSIVE WITH
BOUNDARY LAYER MOISTENING INTO WEDNESDAY ACROSS THE REGION GIVEN
POTENTIAL FOR MIXING AND CURRENT/SHORT-TERM FLOW TRAJECTORIES VIA
THE CENTRAL CONUS/GULF OF MEXICO ANTICYCLONE. BUT EVEN SO...BOUNDARY
LAYER MOISTENING WILL OCCUR NEAR A SHARPENING WARM FRONT/ADJACENT
WARM SECTOR AS A PLUME OF STEEP LAPSE RATES ALOFT ADVECTS EASTWARD
TOWARD THE MIDDLE MS VALLEY/TN VALLEY.

SPECIFIC SCENARIO CONFIDENCE IS NOT PARTICULARLY HIGH GIVEN
ANTICIPATED NEBULOUS/LOW AMPLITUDE WEST-NORTHWESTERLY FLOW
ALOFT...POTENTIAL FOR WARM SECTOR CAPPING...IN ADDITION TO VARIED
GUIDANCE SOLUTIONS. HOWEVER...A SLIGHT RISK APPEARS WARRANTED AT
LEAST IN A CONDITIONAL/ISOLATED SENSE. AN ASSORTMENT OF NUMERICAL
GUIDANCE IS INDICATIVE OF THE POTENTIAL FOR ONE OR MORE
PROGRESSIVE/LOW AMPLITUDE DISTURBANCES ALOFT TO COINCIDE
WITH A RELATIVELY MOIST/POTENTIALLY UNSTABLE AIRMASS IN VICINITY OF
THE AFOREMENTIONED WARM FRONT...AND ALONG/SOUTH OF A
SOUTH-SOUTHEASTWARD MOVING COLD FRONT ACROSS THE UPPER MIDWEST.

INITIALLY...SOME ELEVATED TSTMS CAPABLE OF HAIL CANNOT BE RULED OUT
EARLY IN THE DAY ACROSS THE MIDDLE/UPPER MS RIVER VALLEY. INTO THE
AFTERNOON...INITIAL SURFACE BASED DEVELOPMENT COULD OCCUR ACROSS THE
UPPER MS RIVER VALLEY NEAR A SURFACE LOW/TRIPLE POINT...WITH AT
LEAST A CONDITIONAL SEVERE THREAT POSSIBLE PENDING TSTM DEVELOPMENT.
HOWEVER...THE RELATIVELY MOST CONFIDENT SCENARIO IS FOR TSTMS TO
NOCTURNALLY INCREASE ACROSS THE MIDWEST/OH VALLEY AFTER DARK AS LOW
LEVEL JET AIDED ISENTROPIC ASCENT INCREASES ALONG/NORTHEAST OF THE
WARM FRONT. AT THE VERY LEAST...SOME OF THE STRONGER STORMS WILL BE
CAPABLE OF SEVERE HAIL GIVEN THE PROXIMITY OF STEEP LAPSE RATES
ALOFT/AMPLE ELEVATED INSTABILITY AMID A HIGH DEGREE OF VERTICAL
SHEAR.

...PACIFIC NORTHWEST/NORTHERN INTERMOUNTAIN REGION...
HEIGHT FALLS WILL OCCUR ACROSS THE REGION WITH BACKING/STRENGTHENING
FLOW ALOFT AS AN UPPER TROUGH AMPLIFIES/DIGS SOUTHEASTWARD OFF THE
COAST OF THE PACIFIC NORTHWEST. IT APPEARS THAT ANOTHER DAY OF
SPORADIC HAIL/GUSTY TSTM WIND POTENTIAL MAY BE POSSIBLE ACROSS THE
REGION ESPECIALLY DURING THE AFTERNOON/EVENING GIVEN INCREASING
PRECIPITABLE WATER/VERTICAL SHEAR.

...FAR SOUTHERN CA/AZ...
A SOUTHERN STREAM UPPER TROUGH WILL BECOME MORE PROGRESSIVE AND
APPROACH FAR SOUTHERN CA/NORTHERN BAJA BY WEDNESDAY NIGHT.
ANTICIPATED LIMITED BUOYANCY PRECLUDES SEVERE PROBABILITIES AT THIS
TIME...BUT SOME SMALL HAIL AND/OR WATERSPOUTS CANNOT CURRENTLY BE
RULED OUT FOR COASTAL FAR SOUTHERN CA/ADJACENT OFFSHORE AREAS.

..GUYER.. 04/24/2012

[snowlover2]

Decent probs not to mention a hatched area on the hail probs on the new day 1.



Tornado



Hail



Wind

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1233 AM CDT WED APR 25 2012

VALID 251200Z - 261200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MIDWEST/OH VALLEY
REGION...

...SYNOPSIS...
AS ONE PIECE OF THE ERN U.S. UPPER TROUGH SHIFTS NEWD ACROSS NEW
ENGLAND TODAY...THE OVERALL TROUGHING WILL BE SOMEWHAT MAINTAINED AS
A COMBINATION OF WEAK DISTURBANCES MOVING THROUGH CYCLONIC NWLY FLOW
BEHIND THIS TROUGH AND A STRONGER PIECE OF ENERGY DIGS SEWD ACROSS
WRN ONTARIO AND EVENTUALLY INTO THE UPPER GREAT LAKES.

MEANWHILE FARTHER W...THE TWO CLOSED LOWS -- ONE OFF THE BRITISH
COLUMBIA COAST AND THE OTHER OFF THE CA/BAJA COAST -- APPEAR LIKELY
TO BECOME PARTIALLY PHASED THIS PERIOD...AFFECTING THE W COAST AND
EVENTUALLY THE DESERT SW LATE.

AT THE SURFACE...THE MAIN FEATURE WITH RESPECT TO THE SEVERE WEATHER
FORECAST WILL BE A SURFACE LOW -- INITIALLY PROGGED TO LIE INVOF ERN
SD/SWRN MN. THIS LOW IS FORECAST TO SHIFT SEWD ACROSS THE UPPER
MIDWEST THROUGH THE DAY...ALONG A NW-SE WARM FRONT. LATER...THE LOW
SHOULD TURN EWD AND MOVE ACROSS THE OH VALLEY REGION THROUGH THE END
OF THE PERIOD.

...MIDWEST/OH VALLEY REGION...
AS THE AFOREMENTIONED SURFACE LOW SHIFTS SEWD ACROSS IA DURING THE
DAY AND REACHES THE MS RIVER...A SWLY LOW-LEVEL JET IS FORECAST TO
DEVELOP -- NOSING NEWD TOWARD/ACROSS THE SURFACE WARM FRONT. AS THE
MOISTENING BOUNDARY LAYER DESTABILIZES THROUGH THE
AFTERNOON...EXPECT STORM INITIATION TO OCCUR -- LIKELY NEAR AND TO
THE COOL SIDE OF THE FRONT AS WARM SECTOR CAPPING IS LIKELY TO
LARGELY INHIBIT CONVECTIVE DEVELOPMENT. INITIAL DEVELOPMENT SHOULD
OCCUR INVOF ERN IA/NWRN IL...AND WITH STEEP LAPSE RATES/MODERATE
CAPE FUELING THE CONVECTION...INCREASING STORM COVERAGE -- AND
EVENTUALLY UPSCALE GROWTH INTO A BOWING LINE OF STORMS -- APPEARS
POSSIBLE.

INITIAL STORM MODE IS LIKELY TO BE SUPERCELLULAR...WITH LOW-LEVEL
FLOW VEERING RAPIDLY AND INCREASING TO 40 KT FROM THE NW. THESE
STORMS WILL LIKELY BE ACCOMPANIED BY LARGE HAIL...WITH LOCALLY
DAMAGING WINDS AND EVEN AN ISOLATED TORNADO POSSIBLE. PRESUMING
UPSCALE LINEAR GROWTH DOES OCCUR...THREAT FOR WIND WOULD INCREASE --
AIDED BY MID-LEVEL NWLYS ALOFT INCREASING A BIT TO 40 TO 50 KT
DRIVING A FAST-MOVING MCS ACROSS THE OH VALLEY ROUGHLY ALONG THE
WARM FRONTAL ZONE. SOME SEVERE THREAT MAY LINGER WELL INTO THE
OVERNIGHT HOURS -- PARTICULARLY IF THE LINEAR/BOWING MCS CAN
DEVELOP.

[CentralIllinois]

Decent probs not to mention a hatched area on the hail probs on the new day 1.



Tornado



Hail



Wind

Yea looks good

[WeatherMonger]

0Z WRF-NMM looks decent for NE/E IL into IN

[jdrenken]

Peoria, IL target anyone?

[jdrenken]

[jdrenken]

Close up view on Google Earth...

Attached thumbnail(s)

 

[WeatherMonger]

New update shifted everything pretty good to the SE and casts a lot of doubt

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0749 AM CDT WED APR 25 2012

VALID 251300Z - 261200Z

...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTERNOON INTO
TONIGHT ACROSS PORTIONS OF THE MIDWEST AND OH VALLEY INTO CNTRL
APPALACHIANS...

...SYNOPSIS...

100+ KT MIDLEVEL JET STREAK CENTERED NEAR 41N/143W WILL DEVELOP SEWD
TOWARD THE NRN CA COAST...SUPPORTING THE OPENING AND SUBSEQUENT EWD
PROGRESSION OF UPPER LOW FROM VICINITY OF 30N/128W INTO THE LOWER CO
VALLEY BY 26/12Z. THIS PATTERN EVOLUTION COUPLED WITH THE SEWD
MOVEMENT OF A SHORTWAVE TROUGH FROM NRN MANITOBA INTO THE UPPER
GREAT LAKES WILL CONTRIBUTE TO THE AMPLIFICATION AND EWD DEVELOPMENT
OF MIDLEVEL RIDGE FROM THE INTER-MOUNTAIN WEST INTO THE HIGH
PLAINS.

AT THE SURFACE...LOW PRESSURE OVER SWRN MN WILL DEVELOP SEWD TO
VICINITY OF THE QUAD CITIES BY 26/00Z BEFORE ACCELERATING INTO CNTRL
OH BY THE END OF THE D1 PERIOD. THIS MIGRATORY CYCLONE WILL TRACK
ALONG A WARM FRONT WHICH WILL DEVELOP EWD ACROSS THE OH VALLEY
WITHIN A PERSISTENT LOW-LEVEL WAA REGIME. THE AREA OF LOW PRESSURE
WILL BE TRAILED BY A COLD FRONT WHICH WILL ADVANCE SWD FROM THE NRN
PLAINS AND UPPER MS VALLEY. A PRE-FRONTAL TROUGH IS FORECAST TO
STRENGTHEN TODAY...EXTENDING FROM THE SURFACE LOW SWWD THROUGH NWRN
MO TO S-CNTRL KS WHERE IT WILL LINK WITH A DRYLINE STRETCHING SWD
THROUGH WRN OK INTO W-CNTRL TX.

...MIDWEST/OH VALLEY INTO CNTRL APPALACHIANS THIS AFTERNOON AND
TONIGHT...

RECENT OBSERVATIONAL DATA AND NUMERICAL GUIDANCE HAVE BRED
INCREASING UNCERTAINTY IN THE CONVECTIVE FORECAST LATER TODAY INTO
TONIGHT. MOISTURE QUALITY REMAINS PROBLEMATIC WITH 12Z REGIONAL
SOUNDINGS SHOWING LOWEST 100-MB MEAN-MIXING RATIOS OF ONLY 6-9 G/KG.
THIS COUPLED WITH INCREASING MID AND HIGH-LEVEL CLOUDINESS MAY
IMPACT THE DEGREE OF INSTABILITY THAT DEVELOPS TODAY.
FINALLY...THERE IS SOME INDICATION THAT FORCING ASSOCIATED WITH AN
UPSTREAM IMPULSE MAY MOVE ACROSS THE REGION FAIRLY EARLY
TODAY...PRIOR TO ENVIRONMENT SUFFICIENTLY DESTABILIZING.

BASED ON AN ARRAY OF MODEL SOLUTIONS...THE CORRIDOR FROM E-CNTRL IL
ACROSS CNTRL/SRN IND INTO SWRN OH AND N-CNTRL KY APPEARS TO HAVE THE
HIGHEST LIKELIHOOD OF EXPERIENCING SEVERE WEATHER FROM LATE THIS
AFTERNOON INTO TONIGHT. THIS REGION WILL RESIDE ON THE ERN FRINGE
OF STRONGER CAP ASSOCIATED WITH THE EML WHERE INCREASING BOUNDARY
LAYER MOISTURE AND THE STEEP MIDLEVEL LAPSE RATES WILL YIELD MLCAPE
VALUES RANGING FROM AROUND 1000 J/KG INVOF WARM FRONT TO POTENTIALLY
AS HIGH AS 2000-3000 J/KG OVER WRN IL. THIS INSTABILITY WILL
COINCIDE WITH A KINEMATIC ENVIRONMENT FEATURING A VERTICALLY VEERING
WIND PROFILE /ESPECIALLY ALONG WARM FRONT/ AND 40-50 KT OF DEEP NWLY
SHEAR.

INITIAL STORM MODE WILL LIKELY BE SUPERCELLULAR WITH AN ATTENDANT
RISK FOR LARGE-HAIL...DAMAGING WINDS...AND PERHAPS A TORNADO OR TWO.
THEREAFTER...A NUMBER OF CONVECTION-ALLOWING MODEL SOLUTIONS
INDICATE POTENTIAL UPSCALE GROWTH INTO A BOWING MCS. SHOULD THIS
SCENARIO UNFOLD...THE THREAT FOR DAMAGING WINDS AND HAIL WILL
CONTINUE INTO TONIGHT PERHAPS AS FAR E AS THE CNTRL APPALACHIANS.

...OZARKS...

THE MAJORITY OF MODEL GUIDANCE SUGGESTS THAT THE AIR MASS ACROSS
REGION WILL REMAIN CAPPED TO SURFACE-BASED TSTM DEVELOPMENT.
HOWEVER...OUTLIER SOLUTIONS DO INDICATE THE POTENTIAL FOR ISOLATED
TSTM DEVELOPMENT LATE THIS AFTERNOON AND EVENING ALONG PRE-FRONTAL
TROUGH WHICH WILL TRAIL OH VALLEY SURFACE LOW. INSPECTION OF
FORECAST SOUNDINGS SUGGEST THAT STRONG DAYTIME HEATING AND
CONVERGENCE ALONG THIS BOUNDARY MAY BE SUFFICIENT FOR STORM
INITIATION. ASSUMING A STORM CAN BECOME SUSTAINED...THE COMBINATION
OF MODERATE-STRONG INSTABILITY AND MODEST DEEP-LAYER SHEAR SUGGEST A
RISK FOR SEVERE WEATHER. AS SUCH...LOW PROBABILITIES HAVE BEEN
INCLUDED FOR THIS REGION.

...NRN ROCKIES...

LATEST MODEL GUIDANCE SUGGESTS THAT A WEAK MIDLEVEL IMPULSE EMBEDDED
WITHIN SUBTROPICAL MOISTURE PLUME OVER THE SRN SIERRA-NEVADAS WILL
APPROACH THE REGION LATER TODAY. FORCING ASSOCIATED WITH THIS
FEATURE WILL AUGMENT DAYTIME HEATING ALONG THE HIGH TERRAIN TO GIVE
RISE TO ISOLATED-WIDELY SCATTERED TSTMS LATE THIS AFTERNOON AND
EVENING. SIMILAR TO PREVIOUS DAYS...THE PRESENCE OF STEEP LAPSE
RATES...PW VALUES OF 0.5-0.8 INCH AND 40-45 KT OF DEEP-LAYER SHEAR
WILL SUPPORT A FEW STRONG-MARGINALLY SEVERE STORMS CAPABLE OF HAIL
AND STRONG WIND GUSTS.

..MEAD/LEITMAN.. 04/25/2012

This post has been edited by WeatherMonger: Apr 25 2012, 08:12 AM

[WeatherMonger]

Current satellite

[Snow____]

Plenty sun but it's a bit cool. But then again it isn't even noon yet.

[Juniorrr]

Cloudy with incoming showers.

[WeatherMonger]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1056 AM CDT WED APR 25 2012

.DISCUSSION...
ISSUED 1048 AM CDT WED APR 25 2012
WARM FRONT STARTING TO PROGRESS ACROSS THE CWA THIS MORNING...WITH
SOME SHOWERS DEVELOPING BEHIND IT. FORECAST IS A BIT PROBLEMATIC
AS MID LEVELS ARE VERY DRY AND LIKELY TO START MIXING DOWN AS WE
WARM UP. SHOWERS ARE GOING TO HAVE A HARDER TIME GETTING ORGANIZED
UNTIL LATER THIS AFTERNOON/THIS EVENING WHEN THE WAVE ACTUALLY
STARTS MOVING ACROSS THE MIDWEST. TIMING IS OFF IN DEVELOPING
EXTENSIVE CONVECTION. STRONG INVERSION WITH WARM AND DRY
MIDLEVELS...WITH MAJORITY OF CAPE ELEVATED THROUGH THE EARLY
AFTERNOON...AND WAVE ARRIVES AS MAX HEATING IS ENDING LATER ON
THIS EVENING. THAT BEING SAID...MAY SEE SOME SCT SHOWER ACTIVITY
THROUGH THE AFTERNOON. POTENTIAL IS THERE...BUT WILL HAVE A HARD
TIME COUNTERING THE DRY AIR AND THE CAP. KEEPING THE POPS IN PLACE
FOR SHOWERS AND SCT TS...BUT THE REAL RISK FOR THUNDERSTORMS OF
SIGNIFICANCE SHOULD BE AROUND/AFTER 00Z.

HJS
&&

[CIWeather]

I like their vague wording on the chances for storms later, just using "the real risk," which covers them if nothing happens because then they could say that there wasn't a big chance anyway but that's when the best chances for things to develop were.

[snowlover2]

Wow. Didn't expect to find myself in the highest probs when i woke up today.