The Next Severe Outbreak On Tap!

We started talking about this yesterday and we are going to continue to talk about it as guidance continues to suggest that another severe outbreak will be on Tap. The duration and the extent of it is still sketchy in details at best but you can see that SPC is now hinting at this as well..

BY SUN/D5...THERE IS STRONG EVIDENCE THAT A LARGE UPPER TROUGH WILL
   BEGIN TO TAKE SHAPE ACROSS THE WRN STATES WITH AN 80+ KT MID LEVEL
   JET DIGGING SWD ALONG THE W COAST. THE BOUQUET OF MREF SOLUTIONS AS
   WELL AS DETERMINISTIC MODELS SHOW LITTLE AGREEMENT ON D5 WITH HOW
   QUICKLY AND HOW FAR S THIS TROUGH WILL DEVELOP. THIS WILL HAVE AN
   IMPACT ON THE PROBABILITY OF SEVERE CONVECTION OVER THE SRN/CNTRL
   HIGH PLAINS NEAR THE DRYLINE WHERE CAPPING WILL BE A CONCERN...AND
   ALSO WITH POSSIBLE NOCTURNAL CONVECTION FOCUSED OVER NEB/IA/MO/IL
   OVERNIGHT WITH A SWLY LOW LEVEL JET. BOTH THESE AREAS HAVE
   POTENTIAL...BUT NOT ENOUGH TO INTRODUCE ANY SEVERE AREAS WITH SUCH
   UNCERTAINTY.
   
   FOR THE REMAINDER OF THE PERIOD MON/D6 TO WED/D8...THERE WILL LIKELY
   BE A SEVERE THREAT EACH DAY ALONG THE DRYLINE ACROSS THE CNTRL/SRN
   PLAINS...AND PERHAPS EXTENDING EWD FROM A SURFACE LOW/WARM FRONT
   ACROSS THE MIDWESTERN REGION AS THE UPPER TROUGH...AND/OR PIECES OF
   THE TROUGH EMERGE OVER THE REGION.
   
   SEVERE AREAS BEGINNING SUN/MAY 8TH AND LASTING THROUGH ABOUT MAY
   10TH ARE LIKELY FORTHCOMING FOR MUCH OF THE CNTRL U.S. AS THE EVENT
   NEARS AND PREDICTABILITY INCREASES.

So lets take a look at todays guidance and we are going to be looking at the most extreme guidance as well as the rest of guidance.

This is the most extreme of the guidance which is the UKMET and the reason it is extreme is because it is showing a negatively tilted trough with a surface low getting down to 975 mbs. This type of scenario would indeed set up a pretty severe outbreak across the area.

This is the GGEM which is not nearly as intense as the UKMET ..however it also agrees on the general idea of an area of low pressure with a trough moving from west to east and southerly flow out ahead of the trough.

Here is the GFS ensembles and you can see as well that it agrees with the overall synoptic pattern of an area of low pressure with a trough moving west to east and you also see the southerly flow out ahead of the trough.

If the ECM is correct this trough is going to be very slow to advance eastward and will keep the southerly flow ahead much longer which would also sustain the chances of severe weather longer. You can see by 240 hrs it is trying to send the southerly flow into the NE but it is having some difficult time doing this ..more then likely contributed to the –NAO that is in place.

Now..the GFS has been showing some pretty scary CAPE values on some of its latest runs..

This was 00z last night..

And this is 12 Z today..

As you can see the GFS is suggesting CAPE values in the 5000-6000 range. I personally have not seen CAPE values that high so there is a chance it could be over doing this. However..the dewpoints are in the 70s so the juice is definitely going to be available.

The moral of the story is that it is becoming more apparent that another severe outbreak is on the way but because we are still looking at something in the day 5-6 range it is too early for specifics and to narrow things down.

Stay tuned for more information!