Jeremy Perez
Supporter
With MD509 (May 7, 2014), SPC analyzed two drylines across western Oklahoma and Texas:
DISCUSSION...SURFACE ANALYSIS REVEALS A DOUBLE DRYLINE STRUCTURE ACROSS THE SRN PLAINS. THE PRIMARY DRYLINE IS GENERALLY DEMARCATED BY THE 60 DEG F ISODROSOTHERM WITH THE SECONDARY DRYLINE DEMARCATED BY THE 45 DEG F ISODROSOTHERM....DEEPENING CU IS OCCURRING AHEAD OF BOTH DRYLINES WITH TSTM DEVELOPMENT POSSIBLE ALONG EITHER THIS AFTERNOON.
I'm trying to understand A) what conditions lead to the moisture gradient generating two separate dryline boundaries, and B) how does one detect a double dryline when analyzing surface observations and satellite.
My initial thoughts:
A) Looking at a cross section of dew points, I can visualize a variety of options....sometimes the gradient is diffuse, sometimes sharp, and in this case, perhaps more than one sharp drop, with the drier of the two boundaries still moist enough to support convection.
Assuming I've got that first part somewhat right, the tough part is
B) How do you analyze a double dryline out of surface observations, when satellite and/or radar are providing seemingly ambiguous cues? It doesn't seem like surface observations have enough resolution to pick out two steep DP drops within 50-ish miles of each other. I see a tweaked wind barb at KABI that might be a clue, but it still doesn't seem enough. Which maybe leaves satellite and radar analysis. But when I look at radar and satellite loops leading up to 1915Z, the eastern dryline is easy to pick out, but the only clue of the western dryline is a clump of convection southeast of Childress. All other patterns in the cumulus field seem like they could be gravity wave/orographic in nature...I think this really speaks to my need to get better at reading clues on visible satellite & radar and what I'm not picking out.
I'm grateful for any thoughts or experiences. It would definitely be handy to notice and understand what's going on with an interesting situation like this and make an intelligent choice on targeting developing storms.
DISCUSSION...SURFACE ANALYSIS REVEALS A DOUBLE DRYLINE STRUCTURE ACROSS THE SRN PLAINS. THE PRIMARY DRYLINE IS GENERALLY DEMARCATED BY THE 60 DEG F ISODROSOTHERM WITH THE SECONDARY DRYLINE DEMARCATED BY THE 45 DEG F ISODROSOTHERM....DEEPENING CU IS OCCURRING AHEAD OF BOTH DRYLINES WITH TSTM DEVELOPMENT POSSIBLE ALONG EITHER THIS AFTERNOON.
I'm trying to understand A) what conditions lead to the moisture gradient generating two separate dryline boundaries, and B) how does one detect a double dryline when analyzing surface observations and satellite.
My initial thoughts:
A) Looking at a cross section of dew points, I can visualize a variety of options....sometimes the gradient is diffuse, sometimes sharp, and in this case, perhaps more than one sharp drop, with the drier of the two boundaries still moist enough to support convection.
Assuming I've got that first part somewhat right, the tough part is
B) How do you analyze a double dryline out of surface observations, when satellite and/or radar are providing seemingly ambiguous cues? It doesn't seem like surface observations have enough resolution to pick out two steep DP drops within 50-ish miles of each other. I see a tweaked wind barb at KABI that might be a clue, but it still doesn't seem enough. Which maybe leaves satellite and radar analysis. But when I look at radar and satellite loops leading up to 1915Z, the eastern dryline is easy to pick out, but the only clue of the western dryline is a clump of convection southeast of Childress. All other patterns in the cumulus field seem like they could be gravity wave/orographic in nature...I think this really speaks to my need to get better at reading clues on visible satellite & radar and what I'm not picking out.
I'm grateful for any thoughts or experiences. It would definitely be handy to notice and understand what's going on with an interesting situation like this and make an intelligent choice on targeting developing storms.
