TheWeatherPimp Posted April 8, 2011 Share Posted April 8, 2011 The way this is playing out - Monday could be a big day across Indiana and Western Ohio. Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted April 8, 2011 Share Posted April 8, 2011 Not according to SPC I understand that's what they are saying, but based off the 12z NAM and a slower moving system Sunday/Monday, there will be ample time for destabilization with backed winds across Northern/Northeastern Indiana and Northwestern Ohio on Monday Afternoon/Evening. Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted April 8, 2011 Share Posted April 8, 2011 I understand that's what they are saying, but based off the 12z NAM and a slower moving system Sunday/Monday, there will be ample time for destabilization with backed winds across Northern/Northeastern Indiana and Northwestern Ohio on Monday Afternoon/Evening. Just got our EMA briefing from the NWS and they too are concerned about the Indiana/Ohio threat for Monday Afternoon/Evening - playing up the tornado potential. They are expecting a dying squall line between 4-7 AM Monday Morning with some gusty winds but are much more concerned about discrete cells forming mid to late Monday Afternoon with an enhanced tornado risk. Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted April 8, 2011 Share Posted April 8, 2011 Excellent discussion/write up from Patrick Marsh on day 3 moderate risks http://www.patricktmarsh.com/2011/04/spc-day-3-moderates-in-context/ Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted April 8, 2011 Share Posted April 8, 2011 I don't disagree at all - I am a bit frustrated by the new outlooks. heh I don't understand their reasoning - at all. Guess we will see how it plays out. The NAM is a lot slower and GFS is a lot faster with the whole system. They are worlds apart. For chasing sake, I'm hoping the GFS is correct. Our NWS said that with the trough still digging, they are leaning towards the NAM and thus the increased potential for severe weather Monday Afternoon. Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted April 8, 2011 Share Posted April 8, 2011 As the LLJ increases tonight, things could be hairy across portions of the lower Ohio Valley. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 8, 2011 Author Share Posted April 8, 2011 from Gilbert at NIU I am planning to go with a very rare high risk of severe in my forecast for Sunday night as soon as the models completely come in around 11:30 AM. I plan on holding the forecast until then to see if there are any major changes. Link to comment Share on other sites More sharing options...
A-L-E-K Posted April 8, 2011 Share Posted April 8, 2011 from Gilbert at NIU I am planning to go with a very rare high risk of severe in my forecast for Sunday night as soon as the models completely come in around 11:30 AM. I plan on holding the forecast until then to see if there are any major changes. very nice, Sunday is shaping up to be a pretty rare case study for these parts. Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 8, 2011 Share Posted April 8, 2011 If only... Just west of DSM. Link to comment Share on other sites More sharing options...
JoMo Posted April 8, 2011 Share Posted April 8, 2011 Meanwhile back to today - SREF has been increasing the potential for tornadoes tonight I was not really expecting that. Both the NAM/GFS breaking out convection. I'd watch around the boundary for surface based storms with an evening/night tornado threat. LCL heights will be pretty low. The GFS is indicating more CIN when compared to the NAM at the same time for surface based storms. The NAM is also backing low-level winds more than the GFS. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 8, 2011 Author Share Posted April 8, 2011 If only... for where? still like Nebraska City. Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 8, 2011 Share Posted April 8, 2011 for where? still like Nebraska City. Just west of DSM. Guess I should add that to the original post. Farther SW looks good too. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 8, 2011 Author Share Posted April 8, 2011 Just west of DSM. Guess I should add that to the original post. Farther SW looks good too. you gonna be around to text me what the new day 2 shows? Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 8, 2011 Share Posted April 8, 2011 you gonna be around to text me what the new day 2 shows? Yes...will do. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 8, 2011 Author Share Posted April 8, 2011 Geez, the 12z NAM has 0-1KM EHI's over 8 in southwest IA tomorrow evening, hopefully a storm can tap the juice. Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 8, 2011 Share Posted April 8, 2011 LOT will be holding a wx radio briefing at about 2PM. Link to comment Share on other sites More sharing options...
BryanB Posted April 8, 2011 Share Posted April 8, 2011 What's the severe weather threat look like over eastern Kansas. Hearing some talk of large tornadoes maybe on Sunday Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 8, 2011 Author Share Posted April 8, 2011 Link to comment Share on other sites More sharing options...
Hoosier Posted April 8, 2011 Share Posted April 8, 2011 Just got our EMA briefing from the NWS and they too are concerned about the Indiana/Ohio threat for Monday Afternoon/Evening - playing up the tornado potential. They are expecting a dying squall line between 4-7 AM Monday Morning with some gusty winds but are much more concerned about discrete cells forming mid to late Monday Afternoon with an enhanced tornado risk. The 12z GFS trended a bit slower so who knows at this point. Late last night was the first time I started entertaining the thought of a Monday afternoon threat but it looks possible especially to my east. Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted April 8, 2011 Share Posted April 8, 2011 Here is a slide from the IWX Briefing: Link to comment Share on other sites More sharing options...
upsloper Posted April 8, 2011 Share Posted April 8, 2011 Looks like even parts of Ohio could get into some serious action on Sunday. If temps reach 80, CAPE will be 1500-3000 with a shot at reaching convective temp. So even though the area will be under a ridge, there will also be 50-70kt bulk shear and perhaps very high helicity. Some decent height rises are projected at some point Sunday, but if anything develops before ridging takes a strong effect it could get interesting. LLJ could even help some later in the day. Sounding at Akron: Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 8, 2011 Author Share Posted April 8, 2011 Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 8, 2011 Share Posted April 8, 2011 I don't disagree at all - I am a bit frustrated by the new outlooks. heh I don't understand their reasoning - at all. Guess we will see how it plays out. The NAM is a lot slower and GFS is a lot faster with the whole system. They are worlds apart. For now I would not put much into the NAM. Euro/GFS and strongly nudged to the Euro which is a tick slower but mainly because it is deeper. NAM just doesn't even look realistic. Link to comment Share on other sites More sharing options...
janetjanet998 Posted April 8, 2011 Share Posted April 8, 2011 lets not forget about today decent wind threat and hatched hail MESOSCALE DISCUSSION 0370 NWS STORM PREDICTION CENTER NORMAN OK 1202 PM CDT FRI APR 08 2011 AREAS AFFECTED...PARTS OF SRN INDIANA...SRN OH...MUCH OF CNTRL/ERN KY INTO WRN WEST VA CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 081702Z - 081900Z A WW LIKELY WILL BE NEEDED WITHIN THE NEXT COUPLE OF HOURS. DESTABILIZATION ASSOCIATED WITH BOUNDARY LAYER MOISTENING AND WARMING IS NOW WELL UNDERWAY ACROSS PARTS OF THE LOWER OHIO VALLEY INTO THE CENTRAL APPALACHIANS. MID-LEVEL TEMPERATURES ACROSS THIS REGION WILL BE SLOWER TO WARM IN THE FACE OF THE BUILDING UPSTREAM BROADER SCALE RIDGE...AS MID-LEVEL FLOW GRADUALLY VEERS FROM WESTERLY TO NORTHWESTERLY...AND A LOW AMPLITUDE SHORT WAVE IMPULSE TURNS FROM JUST NORTH OF THE OHIO RIVER TOWARD THE MID ATLANTIC COAST. SO INHIBITION APPEARS LIKELY TO REMAIN RELATIVELY WEAK AS FAR WEST AS PARTS OF SOUTHERN INDIANA AND CENTRAL KENTUCKY...EVEN AS STRONGER MID-LEVEL FORCING FOR UPWARD VERTICAL MOTION SHIFTS ACROSS SOUTHERN OHIO/NORTHEAST KENTUCKY INTO WEST VIRGINIA EARLY THIS AFTERNOON. LATEST RUC GUIDANCE INDICATES THAT MIXED LAYER CAPE IS ALREADY ON THE ORDER OF 500-1000 J/KG...AND MOST AREAS SOUTH OF THE QUASI- STATIONARY FRONT APPEAR LIKELY TO REACH 1000-1500 J/KG...PERHAPS LOCALLY HIGHER...BY PEAK AFTERNOON HEATING. INITIATION OF STORMS SEEMS POSSIBLE AS EARLY AS 18-19Z...AND WILL BECOME INCREASINGLY PROBABLE THROUGH 21-22Z. IN THE PRESENCE OF STRONG VERTICAL SHEAR BENEATH 50+ KT 500 MB FLOW...SUPERCELLS AND AT LEAST SMALL ORGANIZING STORM CLUSTERS APPEAR LIKELY. LOW-LEVEL FLOW FIELDS ARE SOMEWHAT MODEST /UP TO AROUND 30 KT AT 850 MB/...BUT THERMODYNAMIC PROFILES SHOULD STILL BE SUPPORTIVE OF THE RISK FOR POTENTIALLY DAMAGING WIND GUSTS...AND THEY APPEAR QUITE FAVORABLE FOR THE PRODUCTION OF HAIL...SOME OF WHICH COULD BECOME QUITE LARGE AND DAMAGING. AN ISOLATED TORNADO MAY NOT BE OUT OF THE QUESTION. FORCING JUST AHEAD OF A WEAK FRONTAL WAVE SHIFTING FROM SOUTHERN OHIO INTO WEST VIRGINIA COULD PROVIDE ONE FOCUS FOR STORM DEVELOPMENT DURING THE NEXT FEW HOURS. HOWEVER...ACTIVITY GENERALLY APPEARS MORE LIKELY TO DEVELOP INITIALLY IN SCATTERED FASHION WITHIN A BROADLY CONFLUENT LOW-LEVEL REGIME TO THE SOUTH OF THE FRONT...ACROSS PARTS OF SOUTHERN INDIANA THROUGH CENTRAL/EASTERN KENTUCKY. 011 ACUS01 KWNS 081613 SWODY1 SPC AC 081611 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1111 AM CDT FRI APR 08 2011 VALID 081630Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM OK/KS INTO PORTIONS OF THE MID MS AND OH VALLEYS...AS WELL AS THE CENTRAL APPALACHIANS TO THE WRN CAROLINAS... ..SYNOPSIS A STRONG UPPER TROUGH IS FORECAST TO DIG ACROSS CA TODAY...WHILE WEAK UPPER RIDGING TAKES PLACE OVER MOST AREAS EAST OF THE ROCKIES. DESPITE THE RIDGING ALOFT...RATHER STRONG WESTERLY MID LEVEL FLOW AND INCREASING INSTABILITY WILL RESULT IN A RISK OF SEVERE THUNDERSTORMS OVER SEVERAL AREAS TODAY. AT THE SURFACE A FRONTAL BOUNDARY FROM NRN NC EXTENDS NWWD ACROSS APPALACHIANS THRU WRN WV AND THEN WWD TO N OF OH RIVER...THEN WSWWD ACROSS CENTRAL MO TO SWRN KS/OK BORDER. THIS BOUNDARY SEPARATES THE LARGE WARM SECTOR TO THE S WHICH IS UNDERGOING DESTABILIZATION FROM BOTH THE PRESENCE OF AN EML AND ADVECTION OF GULF MOISTURE...AND A COOLER AIR MASS TO THE N. ..OH/TN VALLEYS TO WRN CAROLINAS RAPID DESTABILIZATION IS TAKING PLACE EWD ACROSS KY/TN TO S OF FRONTAL BOUNDARY WITH DEWPOINTS RISING INTO THE MID 60S. STRONG HEATING IS OCCURRING THIS AM OVER LOWER OH VALLEY AND WILL LEAD TO A MDTLY UNSTABLE...WEAKLY CAPPED AIR MASS BY EARLY THIS AFTERNOON. MLCAPES AOA 2000 J/KG COUPLED WITH BRN SHEAR OF 50-60KT WILL PROVIDE A FAVORABLE SEVERE THUNDERSTORM ENVIRONMENT PARTICULARLY FOR LARGE HAIL GIVEN THE STEEP MID LEVEL LAPSE RATES. STORMS SHOULD INITIATE VICINITY/S OF THE FRONTAL ZONE NEAR OH RIVER BY EARLY/MID AFTERNOON AND THEN QUICKLY EVOLVE INTO LINE SEGMENTS/BOWS AS WELL AS POSSIBLE SUPERCELLS. VERY LARGE HAIL WOULD BE POSSIBLE ASSOCIATED WITH ANY SUPERCELL GIVEN THE EXPECTED ENVIRONMENT ALONG WITH ISOLATED TORNADOES. HAVE INCREASED BOTH WIND/HAIL PROBS WITH THE POTENTIAL FOR EVEN A HIGHER RISK OF WIND IF STORMS EVOLVE INTO LINE SEGMENTS AND BOWS. ADDITIONALLY HAVE SPREAD THE SLIGHT RISK INTO THE WESTERN CAROLINAS AS IT NOW APPEARS SUFFICIENT INSTABILITY WILL BE PRESENT TO MAINTAIN AN ORGANIZED THREAT GIVEN THE PRESENCE OF 40-50 KT OF SHEAR. ..OK/KS INTO MID MS AND OH VALLEYS THIS EVENING SURFACE BOUNDARY EXTENDING FROM NEAR THE OK/KS BORDER EASTWARD INTO MO/IL WILL LIKELY BE FOCUS OF SEVERE THUNDERSTORM DEVELOPMENT. OPERATIONAL AND EXPERIMENTAL MODEL SOLUTIONS CONTINUE TO SUPPORT THE DEVELOPMENT OF ISOLATED THUNDERSTORMS BY LATE THIS AFTERNOON OVER NORTHERN OK AND SOUTHEAST KS DESPITE WEAK FORCING ALOFT. STRONG HEATING AND INCREASING MOISTURE WILL HELP TO REDUCE CAP AND AID IN INITIATION. WITH MLCAPES RISING TO 3000 J/KG SUPERCELL STORMS WILL BE LIKELY WITH LARGE HAIL AND DAMAGING WINDS POSSIBLE. THE ACTIVITY IS EXPECTED TO INCREASE IN COVERAGE AS IT SPREADS EASTWARD ALONG THE BOUNDARY INTO THE MID MS VALLEY...AND EVENTUALLY INTO THE OH VALLEY AFTER MIDNIGHT. DAMAGING WINDS WILL LIKELY BE THE MAIN THREAT...ALTHOUGH LARGE HAIL WILL REMAIN POSSIBLE. IF SUPERCELL STRUCTURES CAN BE SUSTAINED IT WILL INCREASE THE POTENTIAL FOR TORNADOES AND VERY LARGE HAIL. EXPECTED COVERAGE PRECLUDES THE INCREASING LOWER RISK COVERAGE PROBABILITIES ATTM. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 8, 2011 Share Posted April 8, 2011 I just noticed the RGEM has been fixed on Ewall. I do find the RGEM a somewhat useful piece of guidance in convective scenarios under certain circumstances. Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted April 8, 2011 Share Posted April 8, 2011 Wow not sure I agree with the new Day 2 but oh well Link to comment Share on other sites More sharing options...
earthlight Posted April 8, 2011 Share Posted April 8, 2011 I just noticed the RGEM has been fixed on Ewall. I do find the RGEM a somewhat useful piece of guidance in convective scenarios under certain circumstances. They have the RGEM on Ewall? Where at? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 8, 2011 Share Posted April 8, 2011 They have the RGEM on Ewall? Where at? It is in the regional 6 panels as the CMCREG. http://www.meteo.psu...regions12z.html Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 8, 2011 Share Posted April 8, 2011 12z SPC WRF for this evening... Link to comment Share on other sites More sharing options...
JoMo Posted April 8, 2011 Share Posted April 8, 2011 yeah the RUC/HRRR have been indicating storm initiation late this afternoon over OK. Last I checked LI's were -9 and SBCAPE was 3000. Link to comment Share on other sites More sharing options...
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