A Day's Difference...Chasers Rejoice!

I knew as soon as I went out on a limb with a pessimistic long range forecast, the models would change. It is appearing likely that I'll lose a bet to Jay and have to wear a bright pink shirt on my next chase trip. LOL!!

The ECMWF jumped on this first along with the Canadian model. Now, the 12z GFS is joining the chorus. Starting next Monday, a strong trough comes onshore and by Tuesday, the models advertise some stormchasing nirvana to erupt across the plains. It is a pattern more normal for May and would continue the trend we've seen in the upper air patern for the past several months.

Details are of course unreasonable to try and forecast this far out. But, the important thing I'm hanging my hat on is the "trend" being advertised by the models. I'll wait for a couple more days of model runs to try and gauge the trend to weigh against the solutions offered. At least we'll have something to watch. :-)

From the afternoon AFD from DDC: DAYS 3-7... AFTER A RATHER LENGTHY PERIOD OF RELATIVELY QUIET WEATHER FOLLOWING THE TORNADO OUTBREAK OF 4-5 MAY, WESTERN KANSAS WILL RETURN TO A VERY ACTIVE FLOW REGIME DURING THIS PERIOD. ANOMALOUSLY STRONG HIGH LEVEL WESTERLIES ARE PROPAGATING EASTWARD ACROSS THE TROPICAL PACIFIC AND ARE INTERACTING WITH THE UPPER LEVEL CYCLONE THAT WAS CENTERED NEAR 48N 150W EARLY THIS AFTERNOON. ANOMALOUSLY STRONG NORTHWESTERLY HIGH LEVEL FLOW IS EVIDENT NEAR THE DATELINE ON THE WEST SIDE OF THE DEEP PACIFIC CYCLONE, AND THIS SUGGESTS THAT THE CYCLONE WILL TEND TO DIG INTO THE DEVELOPING LONG WAVE TROUGH OVER THE WESTERN UNITED STATES. THIS EVOLUTION HAS A NUMBER OF SIMILARITIES WITH SEVERAL PREVIOUS EPISODES OF AMPLIFYING TROUGHS OVER THE WESTERN UNITED STATES THAT SUBSEQUENTLY HAVE WALLOWED ACROSS THE CENTRAL PLAINS. THIS CYCLIC PATTERN HAS PREVAILED SINCE AT LEAST LAST DECEMBER, AND NEARLY EVERY EPISODE HAS RESULTED IN SIGNIFICANT WEATHER EVENTS OVER THE CENTRAL PLAINS.

THE ECMWF SEEMS TO HAVE HAD A BETTER HANDLE ON DEEPENING THE UPPER LEVEL TROUGH NEAR 115W THAN THE GFS RECENTLY, AND THE 00Z RUN OF THE ECMWF LOOKS FAIRLY REASONABLE AND AGREES WELL WITH THE OPERATIONAL CANADIAN. SEVERAL ENSEMBLE MEMBERS OF THE 00Z GFS SUGGESTED A DEEP UPPER LEVEL TROUGH NEAR 115W, ALTHOUGH THE OPERATIONAL RUN WAS MUCH LESS AMPLIFIED THAN THE ECMWF. BY 12Z THE OPERATIONAL GFS AND MOST OF ITS ENSEMBLES WERE IN GOOD AGREEMENT WITH DEVELOPING A DEEP UPPER LEVEL TROUGH OVER THE ROCKIES BY 00Z TUESDAY. CONVERGENCE OF MODEL SOLUTIONS TOWARD THIS EVOLUTION LENDS ADDITIONAL CONFIDENCE THAT IT ACTUALLY WILL OCCUR.

SEVERAL EPISODES OF THUNDERSTORMS...SOME SEVERE...LIKELY WILL OCCUR AS THE DEEP UPPER LEVEL TROUGH WORKS ITS WAY TOWARD THE CENTRAL PLAINS EARLY NEXT WEEK. TIMING OF INDIVIDUAL WAVES IS ALMOST IMPOSSIBLE THAT FAR IN THE FUTURE, BUT THERE DOES SEEM TO BE SOME AGREEMENT THAT AN UPPER LEVEL TROUGH WILL ROTATE OVER THE CENTRAL PLAINS MONDAY. INSTABILITY AND SHEAR SHOULD BE SUFFICIENT TO SUPPORT WIDESPREAD THUNDERSTORM DEVELOPMENT, AND SOME OF THE THUNDERSTORMS WILL BE SEVERE. BY TUESDAY, A PACIFIC FRONT WILL APPROACH THE CENTRAL PLAINS, AND WIDESPREAD THUNDERSTORMS SHOULD OCCUR ALONG THE FRONTAL BOUNDARY. A DRYLINE SHOULD PROPAGATE EASTWARD INTO THE TEXAS PANHANDLE TUESDAY, AND THERE MAY BE A TRIPLE POINT OVER SOUTHWESTERN KANSAS. THE CANADIAN AND ECMWF BOTH SUGGEST THAT THIS MAY OCCUR. IF IT DOES, THERE WILL BE A LOT OF SEVERE WEATHER WITH THE POTENTIAL FOR MORE TORNADOES IN WESTERN KANSAS TUESDAY.

Me like! :-) I just hope this time around, towns will be spared.

On another note, I'm working on a video clip of the May 4th Arnett tornado. I ran into a couple of snags with my software, but everything seems to be playing nice with each other again after reloading a few drivers and a patch/update or two. Watch for that in the next day or two.