David Reimer Posted November 9, 2011 Share Posted November 9, 2011 While the GFS and ECMWF are about 12 hours different on timing, both are suggesting a possible severe weather setup across portions of the deep south by Sunday and Monday. The 0Z ECMWF had a 993 MB low centered over the four corners region on Sunday, while the GFS is running much weaker/slower. Either way, it's looking like a strongly forced linear setup at this point. However, we're still several days out. Besides, last time I started one of these threads we have the most impressive November outbreak in Oklahoma in years. Link to comment Share on other sites More sharing options...
Ed Lizard Posted November 10, 2011 Share Posted November 10, 2011 If the GFS and Euro were better synched, judging from the SWODY4-8 discussion, we would have had an area, I think, Monday... Link to comment Share on other sites More sharing options...
Srain Posted November 10, 2011 Share Posted November 10, 2011 The 12Z GFS sure looks bullish for severe weather from TX and points NE beginning Tuesday. While timing of the Baja low is in question, the dynamics do appear to be trending to another November severe weather event. Link to comment Share on other sites More sharing options...
Cheeznado Posted November 11, 2011 Share Posted November 11, 2011 There is a massive difference between the GFS and the Euro with the speed of the ejection of the CA closed low. the Euro is much much faster. So any severe forecast is very iffy right now. Link to comment Share on other sites More sharing options...
tornadotony Posted November 11, 2011 Share Posted November 11, 2011 There is a massive difference between the GFS and the Euro with the speed of the ejection of the CA closed low. the Euro is much much faster. So any severe forecast is very iffy right now. It's a little bizarre, given that the Euro is often a touch slow in ejecting energy out of the SW. It will be interesting to watch. Link to comment Share on other sites More sharing options...
andyhb Posted November 12, 2011 Share Posted November 12, 2011 DAY 3 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0233 AM CST SAT NOV 12 2011 VALID 141200Z - 151200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF E TX... ...SYNOPSIS... STRONG SRN STREAM SHORT-WAVE TROUGH CROSSING NRN MEXICO/NM/FAR W TX IS PROGGED TO CONTINUE MOVING QUICKLY EWD THIS PERIOD...AND SHOULD APPROACH THE MID AND LOWER MS VALLEY REGION BY THE END OF THE PERIOD. MEANWHILE...WITH THIS SYSTEM ROUGHLY PHASED WITH A TROUGH IN THE NRN STREAM...THE RESULTANT WILL BE A LARGE COMPOSITE TROUGH AFFECTING MOST OF THE COUNTRY BY THE END OF THE PERIOD. DIFFERENCES IN TIMING AND EVOLUTION OF THE UPPER SYSTEM BETWEEN THE NAM AND GFS RESULT IN SIMILAR DIFFERENCES IN SURFACE PATTERN. GENERALLY HOWEVER...BOTH MODELS DEPICT A WEAK LOW INVOF THE ARKLATEX DURING THE LATE AFTERNOON...WITH A WEAK TRAILING FRONT EXTENDING ACROSS E TX. THE MAIN CONVECTIVE THREAT THIS PERIOD WILL EVOLVE IN CONJUNCTION WITH THIS SURFACE SYSTEM...AND THE ASSOCIATED SRN STREAM TROUGH CROSSING THE AREA. ...E TX... PERSISTENT NWD ADVECTION OF LOW-LEVEL MOISTURE IS EXPECTED INTO E TX...AND TO SOME DEGREE EWD INTO THE CENTRAL GULF COAST REGION...AS THE APPROACHING UPPER TROUGH SUPPORTS A WEAK SURFACE CYCLOGENESIS OVER THE ARKLATEX REGION DURING THE AFTERNOON. THIS COMBINED WITH SOME COOLING ALOFT WITH THE APPROACH OF THE UPPER TROUGH SUGGESTS WEAK DESTABILIZATION ACROSS E TX AND ADJACENT AREAS AHEAD OF THE SURFACE FRONT -- SUPPORTIVE OF AFTERNOON SHOWER/THUNDERSTORM DEVELOPMENT. THOUGH MODEL UNCERTAINTY RAISES QUESTIONS WITH RESPECT TO POTENTIAL TIMING/LOCATION/INTENSITY OF THE CONVECTION...IT APPEARS ATTM THAT THE DEGREE OF INSTABILITY COMBINED WITH SUFFICIENTLY STRONG SWLY FLOW ALOFT SHOULD SUPPORT SOME SEVERE POTENTIAL. WHILE SUPERCELLS WOULD BE POSSIBLE...LINEAR EVOLUTION WITH TIME APPEARS LIKELY...AND ASSOCIATED THREATS FOR WIND/HAIL APPEAR SUFFICIENT TO SUPPORT THE INTRODUCTION OF A SLIGHT RISK FORECAST ATTM. THREAT WILL SHIFT EWD WITH TIME...WITH SOME RISK POSSIBLY SPREADING AS FAR E AS THE CENTRAL GULF COAST REGION LATE. ..GOSS.. 11/12/2011 Link to comment Share on other sites More sharing options...
Ed Lizard Posted November 14, 2011 Share Posted November 14, 2011 On the Eastern edge of the Central Subforum, but hatched today for parts of the Ohio Valley. Link to comment Share on other sites More sharing options...
Srain Posted November 14, 2011 Share Posted November 14, 2011 SPC expands Slight Risk with latest update: DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CST MON NOV 14 2011 VALID 151200Z - 161200Z ...THERE IS A SLGT RISK OF SVR TSTMS TUE AND TUE NIGHT ACROSS PARTS OF SOUTHEAST TEXAS INTO THE LWR MISSISSIPPI VALLEY... ...SYNOPSIS... WITHIN THE GENERALLY ZONAL STRONGER BELT OF WESTERLIES EXTENDING ACROSS THE NORTHERN TWO-THIRDS OF THE U.S...BROAD UPPER TROUGHING APPEARS LIKELY TO REMAIN PROMINENT ACROSS THE NORTH CENTRAL STATES THROUGH THIS PERIOD. WITHIN THIS REGIME ANOTHER SIGNIFICANT SHORT WAVE IMPULSE IS EXPECTED TO DIG INTO THE NORTHERN PLAINS BY EARLY TUESDAY...BEFORE TURNING EASTWARD THROUGH THE UPPER MIDWEST. AS THIS OCCURS...A REINFORCING COLD INTRUSION IS PROGGED TO THE LEE OF THE ROCKIES. WHILE THE PRIMARY SURFACE CYCLONE EVOLVES ACROSS AND NORTHEAST OF THE UPPER GREAT LAKES REGION...MODELS INDICATE WEAK SURFACE WAVE DEVELOPMENT WILL OCCUR ALONG THE FRONT ACROSS THE SOUTHERN PLAINS INTO UPPER PORTIONS OF THE LOWER MISSISSIPPI VALLEY BY LATE TUESDAY EVENING. THIS IS EXPECTED TO OCCUR IN RESPONSE TO THE NORTHEASTWARD ACCELERATION OF A CLOSED LOW/UPPER TROUGH OUT OF THE MEXICAN PLATEAU. THE UPPER IMPULSE PROBABLY WILL WEAKEN WITHIN THE CONFLUENT REGIME TO THE NORTHWEST OF A SUBTROPICAL RIDGE...WHICH MAY BE SLOW TO LOSE ITS INFLUENCE ON THE EASTERN GULF AND SOUTH ATLANTIC COAST STATES. AHEAD OF THE SOUTHEASTWARD ADVANCING COLD FRONT...AND GENERALLY ALONG AND SOUTH OF THE REMNANTS OF A WEAKENING/STALLING FRONT CURRENTLY EXTENDING ACROSS THE SOUTHERN PLAINS/MIDDLE MISSISSIPPI AND OHIO VALLEYS...AN INFLUX OF MOISTURE SHOULD CONTINUE OFF THE WESTERN GULF OF MEXICO. THIS IS EXPECTED TO CONTRIBUTE TO SUFFICIENT DESTABILIZATION TO SUPPORT THE RISK FOR THUNDERSTORM ACTIVITY...FROM THE WESTERN GULF COAST STATES NORTHEASTWARD INTO PARTS OF THE LOWER OHIO AND TENNESSEE VALLEYS. AT LEAST SOME POTENTIAL EXISTS FOR THE DEVELOPMENT OF A FEW SEVERE STORMS... MAINLY ACROSS SOUTHEASTERN TEXAS INTO PARTS OF THE LOWER MISSISSIPPI VALLEY. ...SOUTHEAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY... AHEAD OF THE SOUTHERN IMPULSE...CONVECTIVE POTENTIAL COULD BE ENHANCED SOMEWHAT BY AT LEAST MODEST MID-LEVEL LAPSE RATES. WITH SURFACE HEATING...MODELS INDICATE MIXED LAYER CAPE ON THE ORDER OF 500 TO 1000 J/KG TUESDAY AFTERNOON...AS A 60-70 KT SOUTHWESTERLY 500 MB JET STREAK NOSES OUT OF THE LOWER RIO GRANDE VALLEY TOWARD THE CENTRAL GULF COAST. COUPLING OF THIS SPEED MAXIMUM WITH A BROAD DOWNSTREAM SOUTHWESTERLY MID/UPPER JET ...TO THE NORTH OF THE SUBTROPICAL RIDGE...IS EXPECTED TO CONTRIBUTE TO CONSIDERABLE THUNDERSTORM ACTIVITY. IN THE PRESENCE OF STRONG DEEP LAYER SHEAR...ORGANIZED CONVECTIVE CLUSTERS AND ISOLATED SUPERCELLS WILL BE POSSIBLE...WITH POTENTIAL FOR AT LEAST LARGE HAIL AND LOCALIZED DAMAGING WIND GUSTS. UNCERTAINTY EXISTS CONCERNING THE STRENGTH OF THE LOW-LEVEL FLOW FIELDS AND SHEAR...DUE TO THE RELATIVELY WEAK NATURE OF THE FRONTAL WAVE...WHICH COULD LIMIT TORNADIC AND BROADER SCALE DAMAGING WIND POTENTIAL. THE STRONGER MID-LEVEL HEIGHT FALLS ASSOCIATED WITH THE SOUTHERN IMPULSE COULD FOCUS ONE CORRIDOR OF SEVERE WEATHER POTENTIAL ACROSS SOUTH CENTRAL AND SOUTHEAST TEXAS DURING THE DAY TUESDAY...PERHAPS INTO PARTS OF LOUISIANA AND MISSISSIPPI TUESDAY NIGHT. ANOTHER CORRIDOR COULD EVOLVE IN CLOSER PROXIMITY TO THE DEVELOPING FRONTAL WAVE...ACROSS PARTS OF THE ARKLATEX THROUGH SOUTHEASTERN ARKANSAS AND PARTS OF WESTERN TENNESSEE/NORTHERN MISSISSIPPI...LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT...WHERE/ WHEN POTENTIAL FOR THE DEVELOPMENT OF LARGER LOW-LEVEL HODOGRAPHS SEEMS BEST. ..KERR.. 11/14/2011 Link to comment Share on other sites More sharing options...
scoresman Posted November 14, 2011 Share Posted November 14, 2011 Pretty close to home (Memphis) for Tuesday. Might have to take a vacation day and go for a drive. Link to comment Share on other sites More sharing options...
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