<div dir="ltr"><div>Here's todays map. The dry line has backed up a bit and tightened. The cold front in NM has moved east to approach the dl. </div><div>
<br></div><div><img src="cid:ii_mar37d0p2" alt="image.png" width="428" height="289"></div><div>
<div>On the surface, it looks like an ideal set up for severe weather in east TX. Look at the sounding for Dallas Fort Worth:</div>
<br><img src="cid:ii_mar3sjks4" alt="image.png" width="484" height="313"><br></div><div>Pay attention to the relation between the blue line and the redline. The redline is the actual temperature path for the rising balloon. The blue line is the temperature a parcel would have if it were lifted up through the atmosphere beside the balloon. The green line is the dewpoint of the air. Notice how the green and red lines form a rough triangle from 900mb up to nearly 500 mb. This is an elevated mixed layer. It is the same warm dry air that is sitting west of the dry line. See sounding for lubbock. <br></div><div><br></div><div><img src="cid:ii_mar46mfr5" alt="image.png" width="484" height="375"><br></div><div>You see that same triangle, but in Lubbock it is sitting on the ground. So between Lubbock and DFW the mixed layer (unstable) has become lifted by the moister cooler air to the east. The dry line represents the point at which the warm, dry, mixed layer has been elevated above the surface. It's not a "point"; of course, but a zone in which the dewpoint rises some 50 degrees between Lubbock and DFW. <br></div><div><br></div><div>Now first notice the "nose" on the eml; in the DFW sounding. Along the nostrils of that nose the temperature of the air rises with altitude, despite the lapse rate. In fact the potential or sea level relative temperature rises around 7 degrees C in just a few meters. This nose is called the cap. The area to the right of the blue line, the nose itself, is the amount of lifting that must be be produced by latent heat of condensation before the cap is broken. Once we have accumulated that much lifting we read the level of free convection, where the redline crosses the blue. Here every lifted parcel will be warmer than the surrounding air for the next several thousand feet. Once the cap is broken, one gets explosive development of cumulus clouds and because they are developing through the dry air of the eml, they have that wonderful etched look that characterizes western thunderstorms. <br></div><div><br></div><div>I don[t know why DFW; has no severe alerts for today. I suspect once again, it is the lack of upper air support. The jet over tx is not that robust and there doesnot appear to be much vorticity with it. But whaddoooeyeno. <br></div><div><br></div><div>I will say this: if ever you wanted to have an illustration of what a dry line is and how it affects the structure of the atmosphere to the east of it, the diagrams above are perfect for that purpose. You might save them somewhere.</div><div><br></div><div>I have to quit now, but I took George over the coals about his estimate of water loss last night, and he amitted to have not heeded my stipulation that exertion was low. So, for low exertsion, half a ltry per hour is the better estimate. gutta run Nick</div><div><br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, May 15, 2025 at 10:38 AM Nicholas Thompson <<a href="mailto:thompnickson2@gmail.com" target="_blank">thompnickson2@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><br></div><div>The Dry line is way east in TX. </div><div><br></div><div><img src="cid:ii_mapkxeyb0" alt="image.png" width="428" height="327"><br><br></div><div>The chief implication for Santa Fe is the very low dew points. Under these conditions, George says (and I quote), <br></div><div><span style="font-family:comic sans ms,sans-serif"><i><b><br></b></i></span></div><div><i style="font-family:comic sans ms,sans-serif"><b>"
Given this low humidity and the altitude, your estimated water loss from light household chores in one hour would be about 1.46 liters (roughly 1.5 liters).
"</b></i></div><div><br></div><div>REALLY? It seems to me that at this rate I will be a piece of beef jerky by noon</div><div><br></div><div>One might ask, why there is no severe weather in east Tx. The answer seems to be in the lack of upper air support. (Note ridgey configuration of jet stream over TX. </div><div><img src="cid:ii_mapl95xv1" alt="image.png" width="464" height="281"><br></div><div>Stay hydrated out there. I don't know about the rest of you, but I can get REALLY CRANKY under these conditions. .</div><div dir="ltr" class="gmail_signature"><div dir="ltr"><br></div><div>Nick <br></div></div></div>
</blockquote></div><div><br clear="all"></div><br><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div>Nicholas S. Thompson</div><div>Emeritus Professor of Psychology and Ethology</div><div>Clark University</div><div><a href="mailto:nthompson@clarku.edu" target="_blank">nthompson@clarku.edu</a></div><a href="https://wordpress.clarku.edu/nthompson" target="_blank">https://wordpress.clarku.edu/nthompson</a></div></div>