Area Forecast Discussion
Issued by NWS Midland/Odessa, TX
Issued by NWS Midland/Odessa, TX
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
392 FXUS64 KMAF 202125 AFDMAF Area Forecast Discussion National Weather Service Midland/Odessa TX 425 PM CDT Fri Sep 20 2024 ...New AVIATION... .SHORT TERM... (This afternoon through Saturday night) Issued at 139 PM CDT Fri Sep 20 2024 WV imagery shows the west coast trough inching down the SoCal coastline this afternoon, resulting in progressive southwest flow aloft over West Texas and Southeast New Mexico. The ESE progression of this feature is whittling down thicknesses, and highs this afternoon should be 2-3 F cooler than yesterday as a result. A weak dryline is already shaping up west of the Guadalupes, and upslope flow will kick off some isolated to scattered convection over the higher terrain this afternoon. This activity will diminish somewhat w/loss of daytime heating, but models develop a 40+kt LLJ overnight, which could keep it going into the overnight hours. This will also, along w/mid/high cloud, retard radiational cooling, keeping overnight minimums ~13-15F above normal. Saturday, the upper trough is forecast to eject to the Four Corners by 00Z Sunday. This will push a Pac front into the CWA, but models have been consistent in stalling it over the northwestern zones. This will serve as a focus for increased chances of convection, mainly during the afternoon and evening. CAMs continue to develop 35-45 kts of deep layer shear over the northwest half of the CWA at the trough approaches. Forecast soundings depict dcape in excess of 1000 J/kg, and dry subcloud layers/inverted-V signatures. Mid-level lapse rates continue to be tepid, and steeper rates favorable to severe hail continue to remain north and west of the CWA. Thus, damaging winds appear to be the main threat. If sever hail transpires, northwest Eddy County looks most favorable. Thicknesses continue to diminish, especially northwest, highs should drop another 5 F on average. Saturday night, a cold front approaches from the north, w/convective chances spreading northeast as the trough ejects further up into Colorado. The NAM12 still has the front north of the area at 12Z, but cooler air from the Pac front looks to filter into Southeast New Mexico, cooler overnight lows there. && .LONG TERM... (Sunday through Thursday) Issued at 139 PM CDT Fri Sep 20 2024 Ridging will continue to weaken as troughing develops over the central CONUS by this weekend and a series of embedded short waves move near the area. The first short wave is depicted in all deterministic models to develop from the Four Corners into the Midwest and Great Plains late Sunday into Monday. A second short wave is depicted in the GFS and ICON models to develop and amplify from the Front Range of the Colorado Rockies into the Southern Great Plains. Afterward, models and forecast grids indicate lower rain chances as thicknesses and heights rise with ridging building in again across the southern CONUS. Frequent rain chances late this weekend into the end of next week are indicated in deterministic and ensemble models courtesy of this active weather pattern aloft as well as lift provided by surface cold fronts. The first cold front/dryline oriented SW to NE associated with the short wave late Sunday into Monday is expected to bring isolated to scattered shower and storm chances to the area. The second cold front oriented more east to west and moving south late Tuesday into Wednesday is expected to bring widespread shower and storm chances late Tuesday into Wednesday before rain chances begin to taper off Thursday into Friday. By next Saturday, the Grand Ensemble, European ENS ensemble, NCEP GEFS ensemble, and Canadian GEPS ensemble all depict at least half an inch of rain north of I-10 by next Saturday. NBM rain totals for next Saturday depicts an inch or more of rain only over the northern Permian Basin, particularly the Western Low Rolling Plains where amounts approach 1.50 inches and expected totals have increased in most recent runs to near 2 inches in the northeasternmost parts of the CWA. Higher amounts closer to 1 inch were over Lea County, but have come down below 0.50 inch in most recent runs. GEPS is an outlier, showing amounts over 1 inch north of 1-10 and above half an inch south of I-10 by next Saturday, whereas ENS shows lowest amounts south of I-10, with Grand Ensemble and GEFS most similar and in between the higher rain total forecast in the GEPS and lower rain total forecast in the ENS. Spread in GEPS shows possibility of at least 1.50 inches for most of the Permian Basin in the mean and 75th percentiles. We will continue to monitor the forecast for rain totals for this week to see how this changes. While the forecast shows wetting rains expected, this is expected to be in the form of daily shower and storm chances during the afternoon, and it is possible that if the upper air pattern features troughs with associated mid- level moisture and instability located farther north over the central CONUS, widespread rain will be less likely. Additionally, there has been a trend for models to overpredict rain totals and then lower totals as an extended rainier weather pattern draws near. Widespread severe weather after this Saturday is not currently indicated in SPC forecasts, but model soundings depict sufficient shear and CAPE for the possibility of strong storms. As is common during active weather, there is uncertainty regarding timing and placement of forcing mechanisms. We will see how the smaller scale mesoscale details shape up as next week draws closer. With increased cloud and rain chances limiting daytime heating, highs near to below average Sunday in the 80s, 90s Upper Trans Pecos and near the Rio Grande, triple digit heat along the Rio Grande, will give way to highs around 5 degrees below average in the 70s north of the Rio Grande basins and 80s within and south of the basins Monday, with 90s limited to along the Rio Grande. Temperatures warm up to near average Tuesday but again cool down similar to a few degrees below average Wednesday with the second cold front passage. Highs Monday and Tuesday as well as lows Monday night and Tuesday night have trended lower in most recent NBM runs. Highs remain in the 80s, 70s in higher elevations, and 90s limited to near the Rio Grande and along the Pecos River in the southern Permian Basin Thursday into Friday, as cloud cover and rain chances decrease. Lows slightly above average in the 50s and 60s, 70s near the Rio Grande are expected each night Sunday night through Friday night, with lows below average only expected for northernmost parts of the CWA Sunday night. Monday is currently expected to have the lowest high temperatures in the long term. && .AVIATION... (00Z TAFS) Issued at 423 PM CDT Fri Sep 20 2024 VFR conditions will prevail most terminals for the next 24 hours in return flow, gusty at times during the afternoon. Patchy stratus is anticipated Saturday morning, w/brief MVFR cigs possible KMAF/KHOB. Otherwise, forecast soundings develop a widespread cu field Saturday afternoon, w/bases ~ 6 kft AGL. Convection is possible, but chances are too low for a mention attm. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 73 94 73 87 / 0 10 20 60 Carlsbad 71 94 65 86 / 10 30 20 10 Dryden 73 94 73 92 / 0 0 10 20 Fort Stockton 71 94 72 91 / 0 20 20 40 Guadalupe Pass 67 86 61 81 / 30 20 10 0 Hobbs 69 90 67 84 / 0 30 40 30 Marfa 65 91 65 87 / 0 30 30 30 Midland Intl Airport 72 91 72 87 / 0 10 20 40 Odessa 73 91 73 88 / 0 10 30 40 Wink 72 95 72 91 / 0 30 30 30 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...None. NM...None. && $$ SHORT TERM...44 LONG TERM....94 AVIATION...44