Area Forecast Discussion
Issued by NWS Dodge City, KS
Issued by NWS Dodge City, KS
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038 FXUS63 KDDC 161600 AFDDDC Area Forecast Discussion National Weather Service Dodge City KS 1100 AM CDT Mon Sep 16 2024 .KEY MESSAGES... - First storm system to bring numerous showers and thunderstorms late Tuesday evening/night. Severe weather potential remains very low given the timing after sunset. - Thursday and Friday likely well-above normal temperatures with 75% probability of exceeding 95 degrees for highs Thursday afternoon across the Red Hills region. - Friday Night through Saturday Night, storm number two will provide another round of showers and thunderstorms with greater potential for more precipitation over a larger area than Tuesday Night`s system. && .DISCUSSION... Issued at 326 AM CDT Mon Sep 16 2024 During the overnight (as of 0800Z), radar showed scattered showers and an isolated lightning flash or two north of a Dodge City to Larned line up toward I-70. This activity appeared to line up with a subtle convergence zone centered around 700mb per RAP objective analysis fields. On the larger scale, an impressive upper low was centered across northern California with a jet streak in the mid- upper troposphere digging down the west side of the low, suggesting further maturing of this mid level cyclone. The upper low will be slow to move east today, and our southwestern Kansas region will not feel the effects of this system today or tonight. Winds will remain out of the south to southeast 15 to 20 mph as the leeside trough remains in place, slowly deepening across the central and northern High Plains through the day and tonight. As far as temperatures go, we will continue the trend of going above straight NBM for afternoon temperatures, incorporating 75th to 90th percentile NBM temperatures, as this has worked well in this pattern given antecedent dry conditions. Some of the CAMs suggest an isolated to widely scattered storm or two developing across the eastern TX-OK panhandle and adjacent southwest KS this afternoon, but feel this is overdone given the absence of appreciable boundary layer convergence, thus will keep POPs below 15 percent today and tonight. There is a greater signal of more organized showers and thunderstorms clipping our northwest counties of far west central KS later this evening, much like last evening, and we will keep POPs around 15-20 percent for this activity. Our best chance for numerous showers and thunderstorms will be late Tuesday evening and through the night Tuesday Night as the storm out west finally moves northeast out of the Rockies and across the Northern Plains. Latest NBM POPs are still around 60 percent for much of the forecast area Tuesday Night, and it still appears much, if not all of the precipitation will be associated with sub-severe convection given timing well after sunset and fairly marginal moisture and instability. Latest SPC Day 3 convective outlook keeps a Marginal Risk (1 of 5) across eastern Colorado given the mentioned reasoning. Nevertheless, much of our southwest and west central Kansas should still see modest rainfall given the magnitude of the large scale forcing for ascent as main mid-upper jet streak exit region overspreads western Kansas late in the evening/overnight. Latest NBM suggests region of highest precipitation potential across our northwestern counties with 75th percentile 24-h QPF of one-half inch or greater generally west and northwest of a Ulysses to Garden City to Ness City line...which makes sense given the slightly better forcing for ascent and subsequent organized convection closer to the upper level jet exit region. The late Tuesday Night storm system will push through quickly with Wednesday and Thursday quiet, from a precipitation standpoint, in between storm systems. Global models and ensemble systems are still in pretty good agreement of the next big storm system Friday- Saturday brining our next shot of decent rainfall potential. This will also mark the beginning of the end of our 90-degree September heat. Ahead of wave #2 on Thursday and Friday, though, a rather impressive southwest downslope plume will overspread western Kansas with widespread 90s like and even upper 90s to, yes, even 100-degree potential in the Red Hills region. Latest NBM Probability of 95+ for highs on Thursday are around 75% in the Red Hills region and 40-50% on Friday. The Friday-Saturday storm system will have better low level moisture infusion as well as stronger low level frontogenetic forcing for ascent along with the jet streak approaching. This will yield more widespread potential for greater than one-half inch of rainfall. Once the second wave passes through early in the weekend, much cooler air will push south in its wake. Latest ECMWF ensemble means show highs around the climatological normal of lower 80s Sunday through all of the following week, although there is large spread in the ensemble members with 25-75th percentile range among members 12-17 degrees (F). && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1111 AM CDT Mon Sep 16 2024 VFR is expected through TAF pd. -TSRA/CB will be possible this evening for KHYS and have included this in the TAF. There is a slight chance of -TSRA at KDDC as well, however, confidence is low enough to not include in the TAF for now. Will continue to monitor an adjust as necessary. Otherwise, the rest of the terminals should see little aviation impacts through the morning. SE/S winds 15-20 kt will decrease slightly 12-15 kt this evening. Winds will increase once again 15-20 kt with gusts around 25 kt tomorrow with continued lee troughing. && .DDC WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Umscheid AVIATION...Sugden