Taking a quick look at models for Steve tonight to determine if he wants to venture out on Wednesday.  Work obligations have me tied up so no plains chasing for me this week.  This spring has not went well for me to get away and enjoy my 27 year hobby, but I have to pay the bills and put food in the tummy! 🙂

The northern jet stream is over Canada and has set up a blocking pattern the last several days over the plains.  Two areas of low pressure to note are over the western US, which will eject into the plains mid-week and into the weekend, and the other is spinning and bringing substantial rains to the northeast part of the country.  Nonetheless, severe weather will return to the plains in earnest late this week as the blocking pattern begins to break down.

Taking a look at the surface features for Wednesday, an area of deepening low pressure, on the order of 1000mb, is in the TX panhandle with a warm front draped across the Red River area, while a cold front dips back to the southwest from the low pressure center.  A dry line is setting up across west Texas by 18/12Z.  The dryline is forecasted to mix to the east and be in the eastern TX panhandle and dissecting central TX by 19/0Z.  A secondary area of low pressure is forming in SE CO and the primary area of low pressure is located just east of AMA.

Upper level dynamics will be rounding the base of the western trough by 19/0Z on the order of a 90 to 100 kt jet max out of the west / southwest.  In addition, mid level flow will be strengthening on the order of 70 to 90 kts from the same direction.  The aforementioned features will remain over the southern Rockies Wednesday evening before ejecting out into the plains on Wednesday and Thursday.

 

 

The 700mb flow turns more southwesterly when compared to the 300mb and 500mb charts.

700mb temperatures are negligible for capping issues and appear to be easily overcome with the loss of daytime heating and strengthening LLJ (850mb) on the order of 30 to 40kts.

However, 850mb temps are fairly warm at 0Z/19 and will be source of capping through the afternoon and early evening hours.

Surface temperatures will easily climb into the upper 80’s to mid 90’s on Wednesday afternoon.

 
Dewpoints are forecasted to be in the 50F range.  However, the surface flow is just beginning to modify over the GOM and return the moisture to the southern plains.  Anticipate 60F Dp’s as we head toward the end of the week and into the weekend.

CAPE values are forecasted to be in the 1500-2000J/kg range on Wednesday as the dryline mixes to the east.

CINH is negligible by 0Z/19 but the 850mb temps are concerning early on.

Overall shear values Wednesday are not great, but are still responsive for isolated convection across the forecast area in the 40 to 50kt range.

Crossovers are not impressive and nearly unidirectional across the forecast area.

Wednesday does not bode well for regional severe weather.  However, with the stronger dynamics rounding the base of the trough, the deepening area of low pressure, sharpening dryline and strengthening LLJ I cannot rule out isolated convection across south central OK into north central TX.  Albeit, the main risks with these storms will be isolated wind damage and hailers from more elevated convection on the nose of WAA, versus surface based convection on Wednesday evening.  In addition, Tdd’s will be horrendous. 

If I were setting up for Thursday and Friday I would stay near the WF / dryline intersection in hopes something would fire very near dark Wednesday evening.  However, I don’t hold much hope!  Now, upslope that is a different story…I am liking eastern CO and my favorite locale Limon, CO as a starting point on Wednesday but that is a lot of traveling with little sleep, IMHO, to be set up for Thursday!

Thursday and Friday appear to be somewhat better days dynamic and instability wise but we are still in need of better moisture return across the southern and central plains.  Models are forecasting a modifying flow over the Gulf of Mexico and are advertising a much better moisture return.  This is expected this time of the year but we will need to continue to monitor surface features and look for signs as we move toward mid-week.  In addition, morning convection on Friday may be the fly in the ointment as it was last Wednesday in western OK and western KS. ~ CS

Comments are closed.