Area Forecast Discussion
Issued by NWS Amarillo, TX
Issued by NWS Amarillo, TX
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682 FXUS64 KAMA 080558 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 1258 AM CDT Mon Jul 8 2024 ...New AVIATION... .UPDATE... Issued at 659 PM CDT Sun Jul 7 2024 First round of storms this aftn has focused more along the outflow boundary south of the area rather than the frontal boundary that was pushing through the Panhandles.This suggest we will have to wait for the next upper S/WV and H7 frontal boundary to generate storms after midnight. Given this have lowed POPs across the board for the evening period but did maintain a low POP in the SE in case any outflow pushed back north from SCT TSTMs to the south. It still looks favorable for the overnight storms to pan out especially in the western and southern zones and POPs remain 60-90% after midnight. Given a south shift by most CAMs/HREF of highest QPF and fact that we missed out on the first round, we have removed Beaver and Ochiltree from the Flood Watch and might need to consider removing more of the north later this evening. HREF continues to show 20-50% chance of 1" or greater rainfall across the southern Panhandles. 2 inch or greater probs are 10-20% per the HREF for areas along and especially south of I-40. && .SHORT TERM ... (This evening through Monday night) Issued at 141 PM CDT Sun Jul 7 2024 It is July in the Texas and Oklahoma Panhandle. So you know what that means: boundaries, boundaries, and more boundaries! In this case, as of the latest 18Z obs, we have a cold front moving south-southwest into the northeast combined Panhandles. We also have an outflow boundary from convection in south central Oklahoma moving west-northwest into towards the SE TX Panhandle, and we then have a third, and more subtle sfc boundary across the western TX Panhandle, leftover from thunderstorms earlier this morning. Through this afternoon and towards midnight tonight, these aforementioned boundaries may cause strong to severe thunderstorms to develop. Latest hi-res CAM`s and short range 12Z model data are not quite in an accord of output. LL shear sub 6 km is quite anemic in the latest HRRR/RAP analysis through 00Z tonight across the board. As a result, lift from the series of boundaries in the area will have to help storms reach convection initiation as overall buoyancy alone will not suffice. Best low level moisture content is in the SE TX Panhandle, along with best diurnal heating and no antecedent rainfall from earlier this morning, the highest probability of severe storms should be in this area before midnight tonight. Cannot rule out areas along and ahead of the front as it moves south, or the subtle sfc boundary in the western TX Panhandle, but the highest chances of a severe thunderstorms before midnight is in the southeast Texas Panhandle. Pronounced H850-700 theta-e advection, coupled with effective shear >= 40 kts, along with MLCAPE/SBCAPE of 1000-2000 J/kg will support severe thunderstorms, especially in the southeastern Texas Panhandle. If cold front and westward moving boundary from central Oklahoma collide in the eastern TX Panhandle vicinity, this could definitely aid in thunderstorm development further with areas of lift aiding the environment for lift. Large hail and damaging winds will be the main threats for severe weather, along with the possibility of flooding, especially in the eastern Panhandles with slow moving thunderstorms, as well as PWAt values near 1.5" in some locations. Plenty of low level moisture in the atmosphere. Looking past midnight tonight, latest model and numerical data shows a more organized line of convection developing along the front range of the Rockies which may provide our best rain chances for the Panhandles within the first 24 hours of this forecast. This would support a secondary area of severe thunderstorms favoring the central and western Panhandles for a severe thunderstorm threat of damaging winds and localized flooding. A perturbation across the central Rockies with upslope flow will congeal discrete cells on the front range into a line of storms moving southeast in the combined Panhandle during the overnight hours tonight. Probabilities of severe criteria storms reaching the I-40 corridor is lower than further north near the source of the original storms, along with steering flow being a bit stronger closer to the mountains. But cannot rule out a severe storm anywhere in the Panhandles from midnight tonight through sunrise tomorrow morning. Residual outflow boundaries will move south and further push the main cold front south as well. So going throughout the day tomorrow, rain chances should decrease from north to south. Another quite cool topic to talk about is how nice the temperatures will be behind the passing cold front for tomorrow. High temperatures tomorrow will be in the mid to upper 70s for most areas, a nice change of pace for July. Low temperatures tomorrow night will range in the 50s across the area. Looking at DESI probs, there even is around a 10% chance that portions of the western combined Panhandles may see low temperatures in the upper 40s. Quite refreshing from our normal July heat in the Panhandles. Meccariello && .LONG TERM ... (Tuesday through next Saturday) Issued at 141 PM CDT Sun Jul 7 2024 Mid to long range models indicate that the upper level pattern will change near the start of the extended period. The 500 mb trough should de-amplify and transition towards the northeast CONUS. Meanwhile, upper level ridging overspreads from the west and high pressure builds over much of the CONUS. Here on the High Plains, monsoonal moisture will taper off as our upper level flow turns from northwesterly to northerly. A steady increase with heights aloft will also result in a steady increase in surface temperatures through next week. Southerly surface winds will take over across the CWA, aiding in warm air advection. Tuesday should see highs in the 80`s and they will rise into the 90`s for the rest of the week. A few isolated hot spots may even reach 100 degrees this week like the Canadian River Valley and Palo Duro Canyon. Chances for thunderstorms should also greatly decrease. Initially, for Tuesday and Wednesday, better thunderstorms probs are restricted to the far western Panhandle. Afterwards, isolated afternoon convection cannot be ruled out in certain portions of the CWA as the week progresses, but the confidence this far out in time is extremely low to add mentionable PoPs and the coverage is expected to be quite limited. Rangel && .AVIATION... (06Z TAFS) Issued at 1252 AM CDT Mon Jul 8 2024 VFR conditions are prevailing early this morning at all TAF sites. As showers and storms move into the Panhandles through the overnight hours, expect that at least some periods of MVFR ceilings will occur. Model guidance is a little all over the place as to if storms will directly affect any TAF sites but there remains at least some potential for this to occur and have mention of SHRA or TSRA at all locations. The main timing would be around 07z-15z from north to south. Once storms move through, VFR conditions should prevail once again. Culin && .PRELIMINARY POINT TEMPS/POPS... Amarillo TX 77 57 85 63 / 60 20 10 0 Beaver OK 79 55 86 61 / 20 0 0 0 Boise City OK 77 53 85 58 / 30 0 10 0 Borger TX 82 58 91 64 / 50 10 0 0 Boys Ranch TX 79 55 88 62 / 60 10 10 10 Canyon TX 75 56 84 60 / 70 20 10 10 Clarendon TX 76 59 85 63 / 70 20 10 0 Dalhart TX 78 52 87 58 / 40 10 10 10 Guymon OK 79 53 87 59 / 20 10 0 0 Hereford TX 77 57 87 62 / 70 20 10 10 Lipscomb TX 79 56 86 61 / 40 10 0 0 Pampa TX 77 57 85 61 / 50 10 0 0 Shamrock TX 79 60 87 62 / 70 20 10 0 Wellington TX 80 59 89 63 / 70 20 10 0 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...Flood Watch through this afternoon for TXZ005-009-010-014-015- 019-020. OK...None. && $$ SHORT TERM...88 LONG TERM....55 AVIATION...28