baroclinic_instability Posted April 23, 2011 Share Posted April 23, 2011 Are there free Euro maps where I can view surface dew-points/temps? I went to Plymouth State Weather Page and went to contoured model maps, but I couldn't get it to view. Don't believe that is free. Best you can get is 850 temps. I like using Chinooks page (AMWX poster) for the Euro since he did a nice job choosing colors/contours. http://www.greatlake...CMWF_plots.html Link to comment Share on other sites More sharing options...
Indystorm Posted April 23, 2011 Share Posted April 23, 2011 Use this map only as a rough guide for Monday evening and watch how parameters unfold as we get closer to the event, Mac. Link to comment Share on other sites More sharing options...
ATL_Militarypolice Posted April 23, 2011 Share Posted April 23, 2011 Don't believe that is free. Best you can get is 850 temps. I like using Chinooks page (AMWX poster) for the Euro since he did a nice job choosing colors/contours. http://www.greatlake...CMWF_plots.html Okay thanks for the link. Link to comment Share on other sites More sharing options...
AppsRunner Posted April 23, 2011 Share Posted April 23, 2011 Don't believe that is free. Best you can get is 850 temps. I like using Chinooks page (AMWX poster) for the Euro since he did a nice job choosing colors/contours. http://www.greatlake...CMWF_plots.html You should be able to get ECMWF 850mb DP's on Plymouth's site as well. Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted April 23, 2011 Share Posted April 23, 2011 Very impressive discussion from the Indianapolis Office SHORT TERM /SUNDAY THROUGH TUESDAY/ FOCUS REMAINS ON POTENTIAL FOR SIGNIFICANT FLOODING THROUGH THE PERIOD AS THE FRONTAL BOUNDARY OSCILLATES ACROSS THE REGION. FURTHERMORE...NORTHWARD MOVEMENT OF THE BOUNDARY ON MONDAY AND THE PASSAGE OF A STRONGER SURFACE WAVE MONDAY NIGHT INTO TUESDAY WILL REINTRODUCE THE POTENTIAL FOR WIDESPREAD SEVERE WEATHER ACROSS CENTRAL INDIANA MONDAY AND TUESDAY. THE BOUNDARY WILL REMAIN IN CLOSE PROXIMITY TO ITS CURRENT LOCATION THROUGHOUT THE DAY SUNDAY WITH THE GREATEST POTENTIAL FOR SIGNIFICANT RAINFALL ACROSS SOUTHERN COUNTIES AS ANOTHER DISTURBANCE TRAVERSES THE BOUNDARY. CONVERGENCE AND MOISTURE REMAIN MAXIMIZED WITHIN THIS AREA WITH PERIODIC CLUSTERS OF THUNDERSTORMS AND HEAVY RAINFALL CONTINUING. ONE NOTED CHANGE SUNDAY AFTERNOON AND EVENING WILL BE FOR THE BOUNDARY TO BEGIN LIFTING BACK NORTH ACROSS FORECAST AREA IN RESPONSE TO A SHARP UPPER TROUGH EJECTING OUT OF THE CENTRAL ROCKIES. MORE WIDESPREAD RAINFALL WILL ENCOMPASS THE ENTIRE FORECAST AREA BY SUNDAY EVENING WITH DEEPER MOISTURE PULLING FURTHER NORTH WITH THE BOUNDARY. POTENTIAL FOR FLOODING WILL ALSO EXPAND BACK NORTH BY EARLY MONDAY AS ADDITIONAL DISTURBANCES LIFT NORTH OUT OF THE CENTRAL PLAINS. STRONGER LOW LEVEL FORCING ASSOCIATED WITH THE WAVE ON MONDAY WILL LIKELY PROMOTE A PERIOD OF HEAVIER RAINFALL ACROSS THE ENTIRE FORECAST AREA WHICH WILL ONLY EXACERBATE ONGOING FLOODING. THE FRONT WILL ALIGN NORTH OF THE FORECAST AREA BY MONDAY AFTERNOON. WITH ENTIRE FORECAST AREA SHIFTING TO THE WARM SECTOR...THREAT FOR SEVERE THUNDERSTORMS WILL RETURN TO CENTRAL INDIANA MONDAY AFTERNOON...GROWING INTO TUESDAY AS AFOREMENTIONED STRONG SURFACE LOW PASSES TO THE NORTHWEST OF THE REGION. BL SHEAR VALUES WILL INCREASE ACROSS MUCH OF THE AREA MONDAY AFTERNOON IN AN INCREASING UNSTABLE AIRMASS SOUTH OF THE BOUNDARY. SURFACE HELICITIES WILL ALSO INCREASE WITH 0-1KM VALUES EXCEEDING 100S2/M2 THROUGH THE AFTERNOON AND EVENING WITH ORGANIZED SEVERE WEATHER BECOMING A STRONG POSSIBILITY. WITH THE ARRIVAL OF A 65KT LOW LEVEL JET TRANSPORTING EVEN DEEPER MOISTURE INTO THE REGION...THREAT FOR SEVERE WEATHER SHOULD PERSIST MONDAY NIGHT AND EARLY TUESDAY ALONG WITH A RENEWED CONCERN FOR CONVECTION TRAINING OVER SATURATED AREAS AND INCREASING CONCERNS FOR MORE FLOODING. WITH WET BULB ZEROS AROUND 9KFT AND STEEP LOW LEVEL LAPSE RATES...ALL MODES OF SEVERE WEATHER WILL BE PRESENT...INCLUDING DAMAGING WINDS/LARGE HAIL/TORNADOES. DEPENDING ON HOW QUICKLY THE LOW PRESSURE PULLS AWAY TO THE NORTHEAST TUESDAY...THERE MAY A BRIEF RESPITE WITH CONVECTION BECOMING MORE SCATTERED IN NATURE. YET ANOTHER PIECE OF ENERGY ALOFT EJECTS OUT OF THE UPPER TROUGH AND SPINS UP AN INTENSIFYING SURFACE WAVE LATE TUESDAY NIGHT INTO WEDNESDAY. THIS WILL BRING ADDITIONAL THREATS FOR SEVERE WEATHER AND WIDESPREAD FLOODING RAINS INTO WEDNESDAY AND WILL BE DISCUSSED BELOW IN THE LONG TERM SECTION. TEMPS...GENERALLY TOOK A BLEND OF AVAILABLE MOS WITH HIGHS MAINLY IN THE 60S SUNDAY WARMING INTO THE 70S FOR MOST OF THE AREA MONDAY AND TUESDAY. LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/ UNSETTLED WEATHER CONTINUES INTO THE FIRST PART OF THE EXTENDED AS YET ANOTHER SURFACE WAVE EJECTS OUT OF THE LONGWAVE TROUGH ALOFT AND RIDES ALONG THE FRONTAL BOUNDARY AND INTO THE OHIO VALLEY THROUGH WEDNESDAY EVENING. MODEL CONSENSUS FAVORING AN INTENSIFYING LOW AS IT MOVES INTO THE REGION...WITH A RENEWED SURGE OF RICH GULF MOISTURE NORTH INTO CENTRAL INDIANA. THIS COULD BRING ANOTHER BOUT OF SEVERE WEATHER FOR WEDNESDAY ACROSS MUCH OF THE FORECAST AREA...AND EVEN MORE CONCERNING...ANOTHER ROUND OF TORRENTIAL FLOODING RAINFALL TO THE FORECAST AREA ON TOP OF WHATEVER FALLS THROUGH TUESDAY. DYNAMICS ARE ESPECIALLY IMPRESSIVE ACROSS THE OHIO VALLEY ON WEDNESDAY AS AN 850MB JET IN EXCESS OF 60KTS NOSES INTO THE REGION. MUCH MORE DETAIL ON WEDNESDAY AS THE PATTERN EVOLVES OVER THE NEXT SEVERAL DAYS BUT AT THIS POINT IN TIME...THE HEAVY RAIN/FLOODING THREAT TO CENTRAL INDIANA LOOKS TO LAST AT LEAST THROUGH WEDNESDAY EVENING. HAVE INCREASED TO LIKELY POPS THROUGH WEDNESDAY. FRONT WILL FINALLY KICK EAST AS THE UPPER TROUGH TAKES ALL DAY THURSDAY TO CROSS THE REGION. THIS WILL KEEP COOL AND SHOWERY CONDITIONS ACROSS CENTRAL INDIANA THURSDAY BEFORE HIGH PRESSURE CAN FINALLY BUILD IN THURSDAY NIGHT AND PROVIDE A RESPITE TO THE ACTIVE WEATHER. WILL MAINTAIN CHANCE POPS THROUGH THURSDAY FOR LIGHT SHOWERS AND HIGHS MAINLY IN THE 50S. HIGH PRESSURE WILL KEEP MAINLY DRY CONDITIONS ACROSS CENTRAL INDIANA INTO SATURDAY WITH TEMPS REBOUNDING BACK INTO THE 70S AS RIDGING ALOFT EXPANDS INTO THE OHIO VALLEY. THERE ARE ALREADY HINTS OF ANOTHER SURFACE WAVE MOVING OUT INTO THE CENTRAL PLAINS NEXT WEEKEND AS A STRONG UPPER TROUGH EJECTS OUT OF THE ROCKIES. PLENTY OF TIMING DIFFERENCES ASSOCIATED WITH THIS FEATURE AT THIS POINT IN TIME BUT THINK ITS FAIR TO SAY THIS WILL LIKELY BE THE NEXT SYSTEM TO IMPACT CENTRAL INDIANA SOMETIME NEXT WEEKEND. THE ACTIVE PATTERN CONTINUES. Link to comment Share on other sites More sharing options...
Macintosh Posted April 23, 2011 Share Posted April 23, 2011 Use this map only as a rough guide for Monday evening and watch how parameters unfold as we get closer to the event, Mac. Interesting that you supplied a map with the highest probability spot right over my tiny little Perry County, MO. That's funny. Link to comment Share on other sites More sharing options...
Indystorm Posted April 23, 2011 Share Posted April 23, 2011 Well< Mac, I have relatives both dead and alive from Anna ne to Marion area. Have been to CAPE many times so I have a strong interest in far southern IL. at this time of year weatherwise especially. Link to comment Share on other sites More sharing options...
janetjanet998 Posted April 23, 2011 Share Posted April 23, 2011 18z gfs much stronger with the monday low 994 mb in western MO by 00z tuesday and aorund 991 in western IL by 06z puts STL in corsshairs again Link to comment Share on other sites More sharing options...
Macintosh Posted April 23, 2011 Share Posted April 23, 2011 Well< Mac, I have relatives both dead and alive from Anna ne to Marion area. Have been to CAPE many times so I have a strong interest in far southern IL. at this time of year weatherwise especially. Flooding along the Mississippi and Ohio rivers is going to be intense. Cairo, IL could be in serious trouble. Link to comment Share on other sites More sharing options...
OHSnow Posted April 23, 2011 Share Posted April 23, 2011 Where is the greatest risk of significant tornadoes with this? Will Ohio experience some of the tornadic activity this time? Link to comment Share on other sites More sharing options...
janetjanet998 Posted April 23, 2011 Share Posted April 23, 2011 Memphis NWS for WEDS SOMETHING INTERESTING OF NOTE...GFS STRONG TORNADO PARAMETER IS AROUND 20 WHICH IS PRETTY UNPRECEDENTED /1 OR 2 IS CONSIDERED HIGH/. Link to comment Share on other sites More sharing options...
cyclone77 Posted April 23, 2011 Share Posted April 23, 2011 Monday's setup looks pretty conditional over Missouri and the southern half of Illinois. The NAM has quite a bit of clouds and precip in the warm sector during the day, which severely limits instability. The GFS is less bullish with this, and therefore creates a better scenario for this area. The 18z GFS is actually pretty nice as it has a stronger surface low over Missouri as well as modest instability in the warm sector. Shear profiles are pretty good over eastern Missouri into central/southern Illinois. As Janet mentioned the St. Louis area would again be a hot spot if the GFS pans out. Hopefully as time goes on we'll see less and less precip shown in the warm sector, but I'm not very confident that will happen. Link to comment Share on other sites More sharing options...
cyclone77 Posted April 24, 2011 Share Posted April 24, 2011 00z NAM says forget about chasing Monday anywhere north of Oklahoma or Arkansas. Link to comment Share on other sites More sharing options...
cyclone77 Posted April 24, 2011 Share Posted April 24, 2011 The new 21z SREF holds out a little hope for areas further north. Link to comment Share on other sites More sharing options...
Macintosh Posted April 24, 2011 Share Posted April 24, 2011 I am just speechless looking at these numbers for the coming days We were hit hard down here today with major damage in my immediate local counties. Now looking at the numbers for next week - surely this won't verify. Then the rainfall numbers - we are looking at the event of my lifetime in this area. Beau, what is interesting to me is the amount of true damage we're seeing. Most of the watches/warnings I've seen the last few years have produced pretty mild tornadoes and some wind gust events. Of course, I'm speaking generally. What i've noticed this last couple of weeks is that we're seeing more actual damage, and severe damage at that. Not just tree limbs and metal barn roofs, but whole buildings destroyed. This isn't scientific, just an observation of mine. Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 24, 2011 Share Posted April 24, 2011 The fact that there have already been 12 tornado emergencies speaks for itself. 2010 as a whole had 12. 2008 had 11. As of now, this could be a pretty dangerous outbreak. People need to be on top of this. Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 24, 2011 Share Posted April 24, 2011 Monday's setup looks pretty conditional over Missouri and the southern half of Illinois. The NAM has quite a bit of clouds and precip in the warm sector during the day, which severely limits instability. The GFS is less bullish with this, and therefore creates a better scenario for this area. The 18z GFS is actually pretty nice as it has a stronger surface low over Missouri as well as modest instability in the warm sector. Shear profiles are pretty good over eastern Missouri into central/southern Illinois. As Janet mentioned the St. Louis area would again be a hot spot if the GFS pans out. Hopefully as time goes on we'll see less and less precip shown in the warm sector, but I'm not very confident that will happen. I hope Monday works out chase wise, especially since I didn't head out yesterday. We'll see how things progress, but I don't have much hope due to the cloud/precip issues you mention. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted April 24, 2011 Share Posted April 24, 2011 I hope Monday works out chase wise, especially since I didn't head out yesterday. We'll see how things progress, but I don't have much hope due to the cloud/precip issues you mention. I have class monday night so im out lol Link to comment Share on other sites More sharing options...
on_wx Posted April 24, 2011 Share Posted April 24, 2011 Anything of particular note about this sounding for 21z Tuesday? Link to comment Share on other sites More sharing options...
csnavywx Posted April 24, 2011 Share Posted April 24, 2011 Anything of particular note about this sounding for 21z Tuesday? It's a nice severe sounding, but all crosswise vorticity suggests little tornado threat. I would be mainly worried about wind and some hail. Link to comment Share on other sites More sharing options...
on_wx Posted April 24, 2011 Share Posted April 24, 2011 It's a nice severe sounding, but all crosswise vorticity suggests little tornado threat. I would be mainly worried about wind and some hail. Great thanks it's for my location Link to comment Share on other sites More sharing options...
Chicago Storm Posted April 24, 2011 Share Posted April 24, 2011 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0100 AM CDT SUN APR 24 2011 VALID 251200Z - 261200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS A LARGE PORTION OF ARKANSAS AND INTO SOUTHERN MISSOURI... ...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN PORTIONS OF THE SRN PLAINS EWD/NEWD INTO THE MID AND LOWER MS/MID AND LOWER OH/TN VALLEYS... ..SYNOPSIS A LARGE UPPER TROUGH IS FORECAST TO REMAIN ANCHORED OVER THE CENTRAL U.S. THIS PERIOD...WHILE AN EMBEDDED SHORT-WAVE TROUGH MOVES ACROSS THE SRN PLAINS AND EVENTUALLY INTO THE MO VALLEY LATE. AS THIS STRONG FEATURE PROGRESSES ACROSS THE S CENTRAL CONUS...SURFACE CYCLOGENESIS IS FORECAST...AS A DEEPENING LOW TRANSLATES NEWD FROM THE SRN PLAINS ACROSS MO THROUGH THE AFTERNOON AND EVENING. THIS LOW -- AND AN ACCOMPANYING SURFACE FRONT PROGRESSING SEWD ACROSS THE SRN PLAINS -- WILL BE A FOCUS FOR DEVELOPMENT OF POTENTIALLY SIGNIFICANT SEVERE THUNDERSTORMS THIS PERIOD. ...NERN TX/SERN OK/SERN KS EWD/NEWD INTO THE MID AND LOWER MS/TN/LOWER AND MID OH VALLEYS... POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT IS EXPECTED DAY 2 /MONDAY APRIL 25/ FROM ERN PORTIONS OF THE SRN PLAINS INTO THE MID MS/LOWER OH/TN VALLEY REGION...WITH POTENTIAL FOR STRONG TORNADOES IN ADDITION TO VERY LARGE HAIL AND DAMAGING WINDS. WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST TO BE ONGOING AT THE START OF THE PERIOD...MAINLY ALONG AND N OF THE SURFACE WARM FRONT FROM PARTS OF OK/KS EWD INTO THE OH VALLEY. AS THE STRONG SHORT-WAVE TROUGH INVOF THE TX PANHANDLE REGION EARLY SHIFTS EWD ACROSS TX/OK DURING THE DAY...A WEAK/BROAD SURFACE LOW INITIALLY FORECAST INVOF N TX/OK IS FORECAST TO UNDERGO CYCLOGENESIS...SHIFTING NEWD INTO MO THROUGH THE DAY. THIS WILL ALLOW A SLOW NWD SHIFT OF THE COLD FRONT ACROSS SRN AND CENTRAL MO/SRN IL...WHILE A COLD FRONT SHARPENS AND SWEEPS EWD ACROSS ERN OK. WHILE CLOUD COVER SHOULD ACT TO INHIBIT HEATING -- AND THUS MORE SUBSTANTIAL DESTABILIZATION -- PARTICULARLY ACROSS NRN PORTIONS OF THE RISK AREA...MIXED-LAYER CAPE OF 1000 TO 2000 J/KG IS FORECAST TO DEVELOP AHEAD OF THE FRONT FROM E TX ACROSS THE ARKLATEX INTO AR/SRN MO AND INTO THE MID MS VALLEY REGION. AS THE TROUGH SHIFTS EWD AND THE FRONT SHARPENS...EXPECT VIGOROUS STORM DEVELOPMENT TO OCCUR ACROSS SWRN MO...ERN OK...AND E TX DURING THE AFTERNOON WHICH -- GIVEN STRONG/FAVORABLY VEERING FLOW WITH HEIGHT -- SHOULD QUICKLY BECOME SUPERCELLULAR. ALONG WITH THREATS FOR VERY LARGE HAIL...ESPECIALLY ACROSS E TX AND THE ARKLATEX REGION...TORNADOES ARE ALSO EXPECTED -- A FEW POSSIBLY STRONG/DAMAGING. THESE INTENSE STORMS SHOULD SHIFT NEWD ACROSS THIS REGION WITH TIME TOWARD THE MID MS VALLEY...WITH THE LIKELIHOOD FOR UPSCALE GROWTH OVERNIGHT INTO LINEAR CLUSTERS. ALONG WITH A CONTINUED THREAT FOR A FEW TORNADOES...MORE WIDESPREAD DAMAGING WIND THREAT COULD EVOLVE AS STORMS SHIFT ACROSS THE MID MS AND LOWER OH VALLEY REGIONS THROUGH THE EVENING/OVERNIGHT. ..GOSS.. 04/24/2011 Link to comment Share on other sites More sharing options...
Superstorm93 Posted April 24, 2011 Share Posted April 24, 2011 Day 2 MDT Link to comment Share on other sites More sharing options...
Stebo Posted April 24, 2011 Share Posted April 24, 2011 DAY 3 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0230 AM CDT SUN APR 24 2011 VALID 261200Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS A LARGE PORTION OF THE ERN U.S. FROM THE NORTHEAST SWWD INTO ERN TX/ERN OK... ...SYNOPSIS... AS ONE FEATURE ALOFT EJECTS NEWD ACROSS THE OH VALLEY INTO THE GREAT LAKES AREA...A SECOND WILL DIG QUICKLY SEWD OUT OF THE ROCKIES AND INTO THE SRN PLAINS -- BOTH WITHIN THE LARGER-SCALE TROUGH WHICH WILL KEEP BROAD CYCLONIC FLOW IN PLACE ACROSS A LARGE PORTION OF THE U.S. THROUGH THE PERIOD. WHILE THE INITIAL SURFACE LOW LIFTS NEWD INTO THE GREAT LAKES AND WEAKENS...LEAVING BEHIND A TRAILING FROM THE OH VALLEY SWWD ACROSS THE MID MS VALLEY INTO TX...A SECOND FRONTAL LOW WILL DEVELOP -- AND QUICKLY DEEPEN -- AS IT SHIFTS ACROSS TX AND INTO AR LATE. THIS DEVELOPING LOW WILL CONTRIBUTE TO A POTENTIALLY SUBSTANTIAL SEVERE WEATHER EVENT ACROSS THE ARKLATEX AND MID MS VALLEY REGION. ...ARKLATEX REGION INTO THE MID MS VALLEY AREA... COMPLEX -- BUT POTENTIALLY SIGNIFICANT -- SCENARIO APPEARS TO BE UNFOLDING ACROSS THIS REGION...AS PERSISTENT WARM ADVECTION INVOF A SURFACE WARM FRONT RESULTS IN A SLOW INCREASE IN STORM COVERAGE AHEAD OF A RAPIDLY-APPROACHING UPPER FEATURE DIGGING SEWD FROM THE ROCKIES INTO THE SRN PLAINS. WHILE SEVERE POTENTIAL IS APPARENT ACROSS PORTIONS OF THE AREA -- PARTICULARLY INVOF THE WARM FRONT -- THROUGH MUCH OF THE PERIOD...THREAT SHOULD RAMP UP RAPIDLY FROM W TO E BY LATE AFTERNOON ACROSS SERN OK/E TX...AND THEN INTO THE EVENING ACROSS THE ARKLATEX INTO NRN LA/AR AND EVENTUALLY THE MID MS VALLEY REGION. FLOW ALOFT IS FORECAST TO INCREASE AS THE UPPER SYSTEM APPROACHES...AND AS BACKING/INCREASING LOW LEVEL FLOW EVOLVES IN RESPONSE...SHEAR WILL BECOME HIGHLY-FAVORABLE FOR SUPERCELLS. IN ADDITION...IT APPEARS THAT LOW-LEVEL SHEAR WILL BECOME QUITE FAVORABLE FOR LOW-LEVEL ROTATION -- AND THUS THE POSSIBILITY OF STRONG TORNADOES...ESPECIALLY OVERNIGHT FOCUSED ON AR AND VICINITY. GIVEN THIS POTENTIAL...UPGRADE TO HIGHER CATEGORY RISK APPEARS LIKELY IN LATER FORECASTS. ...SRN APPALACHIANS WWD ACROSS THE TN VALLEY REGION... PERSISTENT CYCLONIC FLOW ALOFT -- AND THE PASSAGE OF SEVERAL WEAK/EMBEDDED FEATURES -- ATOP A MOIST BOUNDARY LAYER DESTABILIZING THROUGH THE AFTERNOON SHOULD RESULT IN WIDESPREAD THUNDERSTORM DEVELOPMENT ACROSS A LARGE PORTION OF THE SERN U.S. -- FROM VA AND THE CAROLINAS WWD INTO THE TN VALLEY AND SOUTHEAST. WITH MODEST BUT SUFFICIENT FLOW ALOFT ACROSS A BROAD AREA...MULTICELL/LOCAL SUPERCELL ORGANIZATION CAN BE EXPECTED WITH STORMS ACROSS A LARGE PORTION OF THIS REGION. DETAILS REMAIN UNCLEAR ATTM...BUT WILL INCLUDE A LARGE PORTION OF THIS REGION IN SLIGHT RISK FORECAST -- MAINLY FOR DAMAGING WIND AND HAIL POTENTIAL...THOUGH AN ISOLATED TORNADO OR TWO IS ALSO POSSIBLE. ...LOWER GREAT LAKES/OH VALLEY REGION... AS A STRONG SHORT-WAVE TROUGH AND SURFACE WARM FRONT LIFT QUICKLY NEWD ACROSS THE REGION...EXPECT WIDESPREAD SHOWERS AND THUNDERSTORMS EARLY IN THE PERIOD...WHICH SHOULD CONTINUE/REDEVELOP THROUGH THE PERIOD. NARROWING DOWN EXACT AREAS OF SEVERE WEATHER POTENTIAL REMAIN DIFFICULT AT THIS TIME WITH WIDESPREAD AREA OF AT LEAST MARGINAL INSTABILITY AND A BROAD AREA OF STRONG FLOW ALOFT/FAVORABLE SHEAR. DETAILS SHOULD BECOME CLEARER IN LATER FORECASTS...BUT ATTM...WILL INCLUDE A LARGE PORTION OF THE LOWER GREAT LAKES REGION SWWD INTO THE OH VALLEY AREA...WHERE POTENTIAL FOR MULTIPLE EPISODES OF STRONG/OCCASIONALLY SEVERE STORMS APPEARS TO EXIST -- INCLUDING THREATS FOR HAIL...DAMAGING WINDS...AND A COUPLE OF TORNADOES. Link to comment Share on other sites More sharing options...
Stebo Posted April 24, 2011 Share Posted April 24, 2011 DAY 4-8 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0350 AM CDT SUN APR 24 2011 VALID 271200Z - 021200Z ...DISCUSSION... WIDESPREAD CONVECTIVE/SEVERE WEATHER EVENT -- ONGOING FROM THE DAY 3 /TUE. 4-26/ PERIOD -- IS LIKELY TO CONTINUE SPREADING EWD ACROSS THE OH/TN VALLEYS AND GULF COAST STATES DAY 4 /WED. 4-27/...AS MEDIUM-RANGE MODELS BOTH FORECAST EWD PROGRESSION OF THE LARGE CENTRAL U.S. TROUGH. AS THE COLD FRONT SHIFTS EWD TOWARD THE APPALACHIANS THROUGH THE AFTERNOON AND EVENING...PRE-FRONTAL WARM SECTOR FEATURING MODERATE INSTABILITY AND STRONG DEEP-LAYER SHEAR WILL SUPPORT CONTINUATION/REDEVELOPMENT OF SEVERE STORMS INTO THE AFTERNOON AND EVENING. POTENTIAL FOR SUBSTANTIAL SEVERE WEATHER -- INCLUDING HAIL/WIND AND ISOLATED TORNADOES -- SUPPORTS CONTINUATION OF A LARGE SEVERE WEATHER THREAT AREA FOR DAY 4. MODEL TIMING WITH RESPECT TO THE SURFACE FRONT AND ASSOCIATED UPPER TROUGH BEGINS TO DIFFER MORE SUBSTANTIALLY DAY 5 /THU. 4-28/...THUS CASTING SOME UNCERTAINTY WITH RESPECT TO LOCATION AND DEGREE OF THREAT E OF THE APPALACHIANS DAY 5. THEREFORE...WHILE POTENTIALLY SEVERE CONVECTION WILL LIKELY SPREAD ACROSS THE ATLANTIC COAST STATES SOMEWHERE BETWEEN LATE IN THE DAY 4 PERIOD AND THE AFTERNOON AND EVENING OF DAY 5...WILL NOT HIGHLIGHT A SPECIFIC THREAT AREA THIS FORECAST. WITH THE FRONT EXPECTED TO HAVE SWEPT OFFSHORE BY THE START OF DAY 6 /FRI. 4-29/...FOCUS SHIFTS WWD AS THE NEXT SYSTEM SHIFTS ACROSS/OUT OF THE ROCKIES. MODELS ARE IN MORE SUBSTANTIAL DISAGREEMENT WITH THE EVOLUTION AND PROGRESSION OF THIS FEATURE...AND THUS WILL NOT HIGHLIGHT ANY LONGER-RANGE THREAT AREAS THIS FORECAST. Some 03z SREF maps too Monday Tuesday First look at Wednesday Link to comment Share on other sites More sharing options...
Indystorm Posted April 24, 2011 Share Posted April 24, 2011 Excerpt from Memphis AFD for Monday-Wed, with expectation of more negatively tilted trough TOMORROW EXPECT A GREATER RISK OF SEVERE WEATHER AS A TROUGH SHIFTS OUT OF THE PLAINS. A 50-60 KNOT LLJ WILL DEVELOP OVER WESTERN PORTIONS OF THE MIDSOUTH MONDAY AFTERNOON. MODELS NOW HAVE THIS TROUGH MORE NEGATIVELY TILTED THAN PREVIOUS RUNS. ABUNDANT MOISTURE WILL REMAIN IN PLACE...ESPECIALLY ACROSS EAST ARKANSAS WHERE PW`S WILL RANGE FROM 1.5 TO 1.75 INCHES. DEWPOINTS IN THE MIDDLE 60S WILL PRODUCE CAPES BETWEEN 1500 AND 2000 J/KG AND LIFTED INDICES WILL RANGE FROM -6 TO -8 DEGREES. LOW AND MID LEVEL DYNAMICS SHOULD RESULT IN SUFFICIENT SHEAR TO SUPPORT SUSTAINED UPDRAFTS AND SUPER CELLULAR THUNDERSTORMS. DEEP DRY AIR ALOFT WILL LIKELY RESULT IN LARGE HAIL. SOUTHERLY FLOW WILL INCREASE ON MONDAY REPLENISHING THE SUPPLY OF WARM MOIST AIR ACROSS THE MIDSOUTH. SPEEDS WILL LIKELY BE SUSTAINED BETWEEN 20 AND 30 MPH WITH GUSTS TO 40 MPH. A WIND ADVISORY WILL LIKELY BE NEEDED. STORMS WILL CONTINUE ON TUESDAY...BUT LACK OF UPPER LEVEL SUPPORT WILL RESULT IN LESS OF A THREAT FOR SEVERE STORMS. IT STILL LOOKS LIKE WEDNESDAY HAS THE POTENTIAL TO DEVELOP INTO A MAJOR OUTBREAK. THIS STORM WILL BE ONE OF THE MORE DYNAMIC SYSTEMS I HAVE SEEN IN A WHILE. FORECAST SOUNDINGS INDICATE INCREDIBLE 0-3KM SRH VALUES OVER 1500M/S2 EARLY WEDNESDAY MORNING...AND MORE REALISTIC VALUES AROUND 300-600 DURING THE DAY. MODELS ALSO NOW FEATURE A 80KT LLJ CENTERED OVER MEMPHIS LATE TUESDAY NIGHT. THE MID LEVEL SHORTWAVE DOES NOT LOOK QUITE AS NEGATIVELY TILTED THIS..RUN BUT IT IS STILL VERY AMPLIFIED. SURFACE WINDS WILL BACK AS A SURFACE LOW TRACKS FROM CENTRAL ARKANSAS INTO WESTERN KENTUCKY RESULTING IN LONG CURVED HODOGRAPHS SUPPORTIVE OF SEVERE THUNDERSTORMS. TORNADOES...POSSIBLY STRONG LONG TRACKED TORNADOES...LARGE HAIL AND DAMAGING WIND ARE ALL POSSIBLE ON WEDNESDAY. Link to comment Share on other sites More sharing options...
NIUmetGF Posted April 24, 2011 Share Posted April 24, 2011 Does look like some decent instability, but not the "short/fat" (concentrated in the lower levels 0-3km) type CAPE more of the "narrow/skinny" cape reaching farther up in the atmosphere. As csnavy referred to, not much in the way of directional shear. You'd like to see the winds backed at the surface(at least past southerly) to increase the potential for streamwise vorticity. Another thing you'd like to see is more of an elevated mixed layer (warm/dry air overtop/capping the moist low levels) Anything of particular note about this sounding for 21z Tuesday? Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted April 24, 2011 Share Posted April 24, 2011 00z EURO much more bullish on the severe weather threat farther North in the Ohio Valley on Tuesday - tracking the low farther NW with a broader and more expansive warm sector Link to comment Share on other sites More sharing options...
Stebo Posted April 24, 2011 Share Posted April 24, 2011 00z EURO much more bullish on the severe weather threat farther North in the Ohio Valley on Tuesday - tracking the low farther NW with a broader and more expansive warm sector Also further Northwest with the low on Wednesday Night compared to the GFS, which has agreement with the GGEM/UKMET/NAM, GFS is the furthest SE with this current forecast Link to comment Share on other sites More sharing options...
janetjanet998 Posted April 24, 2011 Share Posted April 24, 2011 12z NAM coming a little more NW for Mondays event..but cloudy/rainy warm sector..still cape around 1500 looks decent perhaps keep this thread for monday..but then spin one off for tuesday and/or weds? also nam a little more se for weds at 12z Link to comment Share on other sites More sharing options...
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