andyhb Posted May 28, 2012 Share Posted May 28, 2012 Figured I would start this get some more in depth discussion regarding this significant trough that looks to drop east towards the tail end of next week. 00z GFS and CMC both would support severe weather potential, mode is still up in the air at this point (the Euro has been fluctuating a bit over the past couple of days, while the others have generally remained with the same general solution with their respective verbatims). Latest SPC Day 4-8: DAY 4-8 CONVECTIVE OUTLOOKNWS STORM PREDICTION CENTER NORMAN OK 0359 AM CDT SUN MAY 27 2012 VALID 301200Z - 041200Z ...DISCUSSION... AMID A PERSISTENT SPLIT UPPER FLOW REGIME...MEDIUM RANGE GUIDANCE IS GENERALLY SUGGESTIVE OF SOUTHERN STREAM AMPLIFICATION/UPPER TROUGH DEVELOPMENT OVER THE CENTRAL/EASTERN CONUS BETWEEN DAYS 4-6 WEDNESDAY-FRIDAY...ALTHOUGH THE SPECIFIC DETAILS OF MAGNITUDE/TIMING VARY. FOR DAY 4/WEDNESDAY...WHILE FORECAST UNCERTAINTIES PRECLUDE A DELINEATION OF ANY 30 PERCENT SEVERE RISK AREAS...IT DOES SEEM LIKELY THAT A SLIGHT RISK CALIBER SEVERE THREAT WILL EXIST ACROSS THE SOUTHERN PLAINS INCLUDING PORTIONS OF OK/NORTHWEST TX AMID WHAT SHOULD BE A VERY UNSTABLE AIRMASS. OTHER SEVERE TSTMS MAY BE POSSIBLE ON DAY 4/WEDNESDAY ACROSS THE CENTRAL HIGH PLAINS IN VICINITY OF A ROUGHLY NORTH-SOUTH ORIENTED SURFACE TROUGH. WHILE FORECAST UNCERTAINTY INCREASES BEYOND DAY 4...IT SEEMS PLAUSIBLE THAT SOME SEVERE THREAT MAY DEVELOP EASTWARD INTO AREAS SUCH AS THE ARKLATEX/OZARKS AND LOWER-MIDDLE MS RIVER VALLEY BY DAY 5/THURSDAY ALONG/AHEAD OF AN ADVANCING COLD FRONT. THEREAFTER...A SEVERE THREAT MAY SUBSEQUENTLY SPREAD TOWARD THE SOUTHEAST/MID-ATLANTIC STATES BY DAY 6/FRIDAY...WHILE OTHER UPSLOPE AIDED SEVERE TSTMS COULD OCCUR ACROSS THE NM/CO FRONT RANGE/ADJACENT HIGH PLAINS ON FRIDAY. ..GUYER.. 05/27/2012 00z CMC at 96 and 120 hours: 00z GFS at 120 hrs: Link to comment Share on other sites More sharing options...
Met1985 Posted May 28, 2012 Share Posted May 28, 2012 Ya Andy looks very active at the end of the week. Will be interesting to see just how suppressed they low is and were it tracks. It does look like this will need to be closely followed as this could be a significant severe weather outbreak along the south but still early to pin point anything right now. Will be fun the track and very interesting something this strong this far south this time of the year. Link to comment Share on other sites More sharing options...
andyhb Posted May 28, 2012 Author Share Posted May 28, 2012 New Day 4-8: DAY 4-8 CONVECTIVE OUTLOOKNWS STORM PREDICTION CENTER NORMAN OK 0353 AM CDT MON MAY 28 2012 VALID 311200Z - 051200Z ...DISCUSSION... AMID A PERSISTENT SPLIT UPPER FLOW REGIME ACROSS THE CONUS/CANADA...AND WITH AMPLIFICATION DURING THE DAY 3 PERIOD...MEDIUM RANGE GUIDANCE IS GENERALLY SUGGESTIVE OF AN EASTWARD-SHIFTING UPPER TROUGH OVER THE EASTERN HALF OF THE CONUS ON DAYS 4-5 THURSDAY/FRIDAY. THAT SAID...CONSIDERABLE VARIABILITY EXISTS AMONGST 00Z-BASED ECMWF/UKMET/GEFS GUIDANCE REGARDING THE SPECIFIC DETAILS OF AMPLIFICATION/TIMING. WHILE THIS GUIDANCE VARIABILITY PRECLUDES SPECIFIC DELINEATIONS OF 30 PERCENT CALIBER SEVERE RISK AREAS...SEVERE TSTMS /POTENTIALLY WIDESPREAD/ CAN NONETHELESS BE EXPECTED. FOR DAY 4/THURSDAY...SOMEWHAT PENDING MESOSCALE DETAILS FROM THE PRIOR DAY...SEVERE TSTMS WILL BE POSSIBLE ACROSS AREAS SUCH AS THE OZARKS/ARKLATEX TO THE LOWER/MIDDLE MS RIVER VALLEY...AND PERHAPS EVEN PORTIONS OF THE TN/OH RIVER VALLEYS THURSDAY NIGHT/EARLY FRIDAY. FOR DAY 5/FRIDAY...SEVERE TSTMS WILL BE POSSIBLE SOMEWHERE WITHIN A GENERAL CORRIDOR FROM THE TN VALLEY/SOUTHEAST STATES TO THE APPALACHIANS/CAROLINAS AND PERHAPS MID-ATLANTIC STATES /ESPECIALLY PER THE FASTER 00Z ECMWF SOLUTION/. THEREAFTER...EARLY INDICATIONS ARE THAT SEVERE TSTM POTENTIAL COULD INCREASE LATE THIS WEEKEND/EARLY NEXT WEEK ACROSS THE NORTHERN PLAINS. ..GUYER.. 05/28/2012 Link to comment Share on other sites More sharing options...
Buckeye05 Posted May 28, 2012 Share Posted May 28, 2012 Pretty strong wording from Paducah office, and parameters are even better further south: "NUMEROUS THUNDERSTORMS IS FORECAST THURSDAY INTO THURSDAY NIGHT AS A STRONG STORM SYSTEM MOVES EAST FROM THE PLAINS INTO THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS. THE POTENTIAL FOR A SIGNIFICANT SEVERE WEATHER OUTBREAK EXISTS THURSDAY INTO THURSDAY NIGHT...WITH THE POTENTIAL FOR LARGE HAIL... DAMAGING WINDS...AND EVEN A FEW TORNADOES." Link to comment Share on other sites More sharing options...
Met1985 Posted May 30, 2012 Share Posted May 30, 2012 Amazing at were the GFS and the Euro sand on this upcoming event. The GFS is pulling this thing farther south with this system. Looks like lots of rain and could be some pretty severe storms firing up. Maybe a couple squall lines forming. Then behind this thing maybe soem record lows up in the mountains with lows in the 40s and possibly 30s at the highest peaks. Link to comment Share on other sites More sharing options...
Brick Tamland Posted May 30, 2012 Share Posted May 30, 2012 Well, looks like we might actually have something to look out for. It's been a while since we have had a widespread severe weather outbreak. This spring is quiet compared to last year's. Link to comment Share on other sites More sharing options...
Jon Posted May 31, 2012 Share Posted May 31, 2012 SPC DAY 3. NWS RAH has also mentioned possible tornadoes on day 3 in their disco. DAY 3 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0230 AM CDT WED MAY 30 2012 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE EASTERN STATES... ...MUCH OF THE EASTERN STATES... SEVERE POTENTIAL THE FIRST DAY OF JUNE WILL GENERALLY BE TIED TO THE EAST-NORTHEASTWARD ADVANCEMENT OF A POTENT UPPER TROUGH OVER THE EASTERN THIRD OF THE CONUS...FOCUSED ALONG/AHEAD OF AN EASTWARD MOVING COLD FRONT. SOME TIMING/SPATIAL UNCERTAINTIES CARRYOVER FROM THE DAY 2 PERIOD...WITH 00Z ECMWF/NAM GUIDANCE GENERALLY FASTER THAN THE 00Z GFS. NEVERTHELESS...AS THE PARENT UPPER SYSTEM TRENDS TOWARD A SLIGHT NEGATIVE TILT ON FRIDAY...AMPLE FORCING FOR ASCENT/VERTICAL SHEAR WILL CONTRIBUTE TO SUSTAINED STRONG/SEVERE TSTMS WITHIN A DIURNALLY DESTABILIZING BOUNDARY LAYER...WITH THE POSSIBILITY OF 1000-2000 J/KG MLCAPE. THIS WILL BE THE CASE 1/ AHEAD OF THE COLD FRONT AND 2/ ALONG AND SOUTH OF A NORTHWARD-SHIFTING WARM FRONT ACROSS THE MID-ATLANTIC STATES/DELMARVA. DAMAGING WINDS /POTENTIALLY WIDESPREAD/ AND SEVERE HAIL WILL BE THE PRIMARY HAZARDS FROM WHAT SHOULD MAINLY BE A MULTICELLULAR/LINEAR CONVECTIVE MODE. SOME SUPERCELLS...PERHAPS EVEN A TORNADO THREAT...COULD OCCUR PROVIDED SUFFICIENT DESTABILIZATION NEAR THE AFOREMENTIONED WARM FRONT. FARTHER SOUTH...A MORE ISOLATED/MARGINAL SEVERE POTENTIAL IS ANTICIPATED ACROSS THE SOUTHEAST STATES/FL. ...SOUTH-CENTRAL HIGH PLAINS TO LOWER MO VALLEY... CURRENT THINKING IS THAT AT LEAST ISOLATED TSTMS WILL DEVELOP FRIDAY AFTERNOON ACROSS FAR EASTERN NM/SOUTHEAST CO AND THE ADJACENT SOUTH-CENTRAL HIGH PLAINS IN VICINITY OF A SURFACE TROUGH. DETAILED CONFIDENCE IN THIS SCENARIO IS NOT PARTICULARLY HIGH AT THIS TIME...BUT SOME ISOLATED STRONG/SEVERE TSTMS MAINLY CAPABLE OF HAIL MIGHT BE POSSIBLE FRIDAY AFTERNOON/EARLY EVENING. LATER FRIDAY NIGHT AND FARTHER EAST...ELEVATED TSTMS MAY INCREASE ON THE NORTHEAST EDGE OF THE CAP AMID A WARM ADVECTION REGIME ACROSS THE SOUTH-CENTRAL PLAINS/LOWER MO VALLEY. SOME HAIL MIGHT BE POSSIBLE...BUT CONSIDERABLE SPATIAL/SCENARIO UNCERTAINTIES PRECLUDE SEVERE PROBABILITIES. Link to comment Share on other sites More sharing options...
jshetley Posted May 31, 2012 Share Posted May 31, 2012 Well, looks like we might actually have something to look out for. It's been a while since we have had a widespread severe weather outbreak. This spring is quiet compared to last year's. Yeah last spring was wild around here. Had many severe storms down here. Have only had 2 strong storms this spring though. Link to comment Share on other sites More sharing options...
Jon Posted May 31, 2012 Share Posted May 31, 2012 HMM....0z NAM pretty bullish with the CAPE....GFS not so much. Link to comment Share on other sites More sharing options...
andyhb Posted May 31, 2012 Author Share Posted May 31, 2012 HMM....0z NAM pretty bullish with the CAPE....GFS not so much. The GFS has a tendency to underestimate sfc temps and therefore, instability. Link to comment Share on other sites More sharing options...
Solak Posted May 31, 2012 Share Posted May 31, 2012 Part of this mornings Day 2 discussion - emphasis mine. OVERALL...DAMAGING WINDS /POTENTIALLY WIDESPREAD AT THAT/ AND SEVERE HAIL WILL BE THE PRIMARY HAZARDS FROM WHAT SHOULD MAINLY BE A MULTICELLULAR/LINEAR CONVECTIVE MODE ACROSS THE MAJORITY OF THE SLIGHT RISK AREA. THAT SAID...SOME SUPERCELLS...INCLUDING A TORNADO THREAT...COULD OCCUR MAINLY ACROSS VA/DELMARVA REGION INTO SOUTHERN PA/NJ PROVIDED 1/ SUFFICIENT DESTABILIZATION OCCURS NEAR THE WARM FRONT AND 2/ SEMI-DISCRETE DEVELOPMENT OCCURS AHEAD OF THE COLD FRONT WHERE A LINEAR MODE SHOULD BE MORE DOMINANT. SOMEWHAT HIGHER PROBABILITIES/PERHAPS EVEN A CATEGORICAL MODERATE RISK MIGHT BE WARRANTED IN SUBSEQUENT CONVECTIVE OUTLOOKS. Link to comment Share on other sites More sharing options...
HWY316wx Posted May 31, 2012 Share Posted May 31, 2012 If the house is a rock'n... well... you might get away from the windows. Heads up boys. Link to comment Share on other sites More sharing options...
Brick Tamland Posted May 31, 2012 Share Posted May 31, 2012 Looks like this might be the biggest widespread severe threat since the tornadoes came through last April. Link to comment Share on other sites More sharing options...
Marion_NC_WX Posted May 31, 2012 Share Posted May 31, 2012 Its looking like a potent squall line could develop here in the Western part of the State after lunchtime and begin to move east through tomorrow evening. Link to comment Share on other sites More sharing options...
mackerel_sky Posted May 31, 2012 Share Posted May 31, 2012 FWIW,just saw TWC has ENC with a torcon of 3,for tomorrow! Link to comment Share on other sites More sharing options...
Brick Tamland Posted May 31, 2012 Share Posted May 31, 2012 Link to comment Share on other sites More sharing options...
downeastnc Posted May 31, 2012 Share Posted May 31, 2012 Going to be fun I have the day off and Shaggy doesnt go to work till 7pm so anything before 6 is gonna be chaseable so it might be game on......course timing issues could burn me here in the east. Link to comment Share on other sites More sharing options...
Jon Posted June 1, 2012 Share Posted June 1, 2012 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT FRI JUN 01 2012 VALID 011200Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL APPALACHIANS AND UPPER OH RIVER REGION TO PORTIONS MID-ATLC AND CAROLINAS... ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SRN HIGH PLAINS... ...SYNOPSIS... PRIMARY UPPER-AIR FEATURE FOR THIS FCST WILL BE STG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY FROM OZARKS TO WI...AND CONTAINING MID-UPPER LEVEL LOW OVER SRN WI. THIS PERTURBATION IS EXPECTED TO ASSUME NEGATIVE TILT EARLY IN PERIOD AS RELATED VORTICITY PLUME PIVOTS EWD THEN ENEWD ACROSS OH VALLEY AND TN VALLEY REGION. CLOSED CYCLONE ALOFT WILL DEEPEN AND BECOME MORE CLOSELY STACKED WITH SFC LOW MOVING NNWWD FROM OH. DEEP-LAYER CYCLONE SHOULD REACH ERN UPPER MI/NRN LOWER MI AREA BY END OF PERIOD. TRAILING COLD FRONT IS FCST TO START PERIOD OVER ERN PORTIONS KY/TN...SWWD ACROSS MS TO SRN LA. BY 2/00Z...COLD FRONT SHOULD REACH WRN/CENTRAL PA...WRN NC AND WRN PANHANDLE OF FL. COLD FRONT SHOULD REACH NEAR SRN NY...JERSEY SHORE...COASTAL SC AND NRN FL BY 2/12Z. WARM FRONT SHOULD MOVE NNEWD ACROSS VA AND INTO PORTIONS WRN/CENTRAL PA BY 2/00Z...WITH NOTCH OF AT LEAST MRGLLY UNSTABLE WARM-SECTOR AIR NWWD AS FAR AS SERN SHORE OF LE PRIOR TO COLD FROPA. FARTHER SW...SFC LOW SHOULD DEVELOP EARLY IN PERIOD OVER SERN CO AND SHIFT/REDEVELOP SWD ROUGHLY ALONG ERN BORDER OF NM...THROUGH 2/06Z. FRONTOGENESIS WILL OCCUR TO ITS SE ACROSS TX PANHANDLE AND NW TX. ...CENTRAL APPALACHIANS AND UPPER OH RIVER REGION TO MID-ATLC AND CAROLINAS... SCATTERED-NUMEROUS TSTMS ARE EXPECTED TO DEVELOP IN BAND NEAR OR AHEAD OF SFC COLD FRONT BY MIDDAY...OVER WRN PORTIONS OUTLOOK AREA...THEN MOVE NEWD WHILE BACKBUILDING SWD. NET EFFECT SHOULD BE EWD SPREAD AND INCREASE IN BOTH CONVECTIVE COVERAGE AND SVR POTENTIAL AS FOREGOING AIR MASS DESTABILIZES DIURNALLY. DAMAGING GUSTS APPEAR LIKELY WITH DOMINANT QUASI-LINEAR STORM MODE...ENHANCED LOCALLY BY TRACKS OF BOW/LEWP FORMATIONS. MANY WIND-DAMAGE EVENTS MAY OCCUR...ALTHOUGH FCST LOW-LEVEL WIND PROFILES DO NOT YET APPEAR STRONG ENOUGH TO SUPPORT ORGANIZED THREAT OF SIGNIFICANT GUSTS OF 65 KT OR GREATER. PATCHES OR CLUSTERS OF CONVECTION ALSO MAY BECOME SFC-BASED DURING MIDDAY THROUGH AFTERNOON IN FOREGOING WARM SECTOR...AMIDST STRENGTHENING DEEP-LAYER SHEAR PROFILES FAVORABLE FOR SVR. GREATEST RELATIVE SPATIAL OVERLAP/DENSITY OF TORNADO POTENTIAL MAY BE FROM N-CENTRAL/NERN NC ACROSS CENTRAL VA TO CHESAPEAKE BAY REGION. THAT CORRIDOR REPRESENTS SPATIAL OVERLAP OF THREAT FROM 1. EARLIER/MORE DISCRETE AND DIURNAL CONVECTION...WHERE DISCRETE OR EMBEDDED/CLUSTERED SUPERCELLS ARE POSSIBLE BUT SPECIFIC FOCI FOR LOW-LEVEL FORCING ARE MORE NEBULOUS AND UNCERTAIN...AND 2. MORE CERTAIN ARRIVAL OF LATER AFTERNOON/EVENING QLCS ACTIVITY CONTAINING EMBEDDED CIRCULATIONS. FCST HODOGRAPHS...WHILE FAVORABLE IN BOTH REGIMES...DO NOT APPEAR AS LARGE OVER BROAD AREAS AS ON MOST ERN-CONUS TORNADO OUTBREAK DAYS...AND THERE ARE CONSIDERABLE UNCERTAINTIES ATTM REGARDING DENSITY/LONGEVITY OF ANY SUPERCELL MODES. EXTENT/MAGNITUDE OF WARM-SECTOR DESTABILIZATION ALSO REMAINS QUITE UNCERTAIN ATTM...BECAUSE OF LARGE AREA OF ANTECEDENT CLOUD COVER AND PATCHY/CLUSTERED PRECIP. THIS INDICATES DISPLACEMENT BETWEEN MOST UNSTABLE/MOIST MARINE AIR OVER SRN/ERN CAROLINAS AND STRONGEST VERTICAL SHEAR FARTHER N ACROSS PA/WV/MD AND NRN VA. THIS ALSO IS MAIN FACTOR PRECLUDING GREATER SVR PROBABILITIES ATTM. GIVEN THESE FACTORS...PROBABILITIES ARE KEPT WITHIN UPPER REACHES OF CATEGORICAL SLGT RISK BIN FOR NOW...THOUGH UPGRADE IS POSSIBLE LATER TODAY ONCE SOME OF THESE DESTABILIZATION AND MOISTURE FACTORS BECOME BETTER-FOCUSED. Link to comment Share on other sites More sharing options...
Brick Tamland Posted June 1, 2012 Share Posted June 1, 2012 It's very overcast this morning. Maybe that will keep the instability down. But it doesn't sound very good. Link to comment Share on other sites More sharing options...
Isopycnic Posted June 1, 2012 Share Posted June 1, 2012 It's very overcast this morning. Maybe that will keep the instability down. But it doesn't sound very good. Rained out here in Orange co, again. Link to comment Share on other sites More sharing options...
eyewall Posted June 1, 2012 Share Posted June 1, 2012 SEVERAL MITIGATING FACTORS CONTINUE TO WARRANT MAINTENANCE OF SLIGHT RISK OUTLOOK. EARLY MORNING VISIBLE IMAGERY SHOWS WIDESPREAD CLOUDS AND SCATTERED SHOWERS ACROSS THE REGION. THIS COMBINED WITH FORECAST MARGINAL MID LEVEL LAPSE RATES WILL LIMIT UPDRAFT ACCELERATIONS. Link to comment Share on other sites More sharing options...
Brick Tamland Posted June 1, 2012 Share Posted June 1, 2012 SEVERAL MITIGATING FACTORS CONTINUE TO WARRANT MAINTENANCE OF SLIGHT RISK OUTLOOK. EARLY MORNING VISIBLE IMAGERY SHOWS WIDESPREAD CLOUDS AND SCATTERED SHOWERS ACROSS THE REGION. THIS COMBINED WITH FORECAST MARGINAL MID LEVEL LAPSE RATES WILL LIMIT UPDRAFT ACCELERATIONS. Guess that can be good or bad, depending on what you want. If you want more excitement, the clouds need to start clearing. It seems this spring that whenever there is a lot of talk about the possibility of severe weather, nothing really happens. I think we've had more severe storms just from the normal heating of the day type storms than from the potentially big systems. Link to comment Share on other sites More sharing options...
Wow Posted June 1, 2012 Share Posted June 1, 2012 nice and sunny here.. didn't rain at all here.. a little further north it was raining. we all should have a window of a few hours of sun this morning. Link to comment Share on other sites More sharing options...
Brick Tamland Posted June 1, 2012 Share Posted June 1, 2012 Well, it's already 72 here, so the clouds aren't keeping the heat down. Link to comment Share on other sites More sharing options...
Brick Tamland Posted June 1, 2012 Share Posted June 1, 2012 Sun is out in the RTP. Should start heating up nicely now. Link to comment Share on other sites More sharing options...
shaggy Posted June 1, 2012 Share Posted June 1, 2012 Getting plenty of sun here east of 95 so we should be good on instability. Its gonna be a timing thing for me since I work at 7pm tonight. I need stoems to be in the area and severe between 3-6pm. Its heating up nicely with the sun now and we could get lucky and see a few cells fire early? Link to comment Share on other sites More sharing options...
Brick Tamland Posted June 1, 2012 Share Posted June 1, 2012 Do the updates from the Storm Prediction Center come out at set times? Link to comment Share on other sites More sharing options...
shaggy Posted June 1, 2012 Share Posted June 1, 2012 Do the updates from the Storm Prediction Center come out at set times? Yeah. Go to current day 1 outlook and scroll down. They have current time and when the next update is due out. This is what the day 1 outlook says at the bottom. NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z CURRENT UTC TIME: 1431Z (10:31AM), RELOAD THIS PAGE TO UPDATE THE TIME Link to comment Share on other sites More sharing options...
downeastnc Posted June 1, 2012 Share Posted June 1, 2012 SEVERAL MITIGATING FACTORS CONTINUE TO WARRANT MAINTENANCE OF SLIGHT RISK OUTLOOK. EARLY MORNING VISIBLE IMAGERY SHOWS WIDESPREAD CLOUDS AND SCATTERED SHOWERS ACROSS THE REGION. THIS COMBINED WITH FORECAST MARGINAL MID LEVEL LAPSE RATES WILL LIMIT UPDRAFT ACCELERATIONS. Start heading east my friend I think/hope by 1-2 this afternoon things should get going..... Surface cape is up to 2500-3000, LI's -6 to -7, Low level lapse rates at 7 already, surface EHI has a 2 bullseye right over New Bern. Link to comment Share on other sites More sharing options...
downeastnc Posted June 1, 2012 Share Posted June 1, 2012 Sea breeze showing up on vis and might be a early focus point and kick things off for us, also the sandhills region around Fayetteville should also be a favorite early spot...hopefully things hold till 2 or so to let things get nice and unstable...clouds might really kill this event north of central and SE VA as the clouds look pretty stout up that way. Link to comment Share on other sites More sharing options...
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