996 FXUS64 KMAF 300000 AFDMAF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 700 PM CDT Fri May 29 2015 .DISCUSSION... Please see the 00Z aviation discussion below. && .AVIATION... Some storms have developed across the higher terrain of southwest Texas and southeast New Mexico and drifted eastward, though have not impacted area TAF sites. Expect this activity to gradually wane after sunset this evening, with additional showers and thunderstorms expected to develop along and ahead of a cold front that will move southward through the area late tonight. Have not made many changes to the going TAF wrt the timing of the front, as passage around 09Z at KCNM/KHOB, 10Z at KINK/KMAF, 12Z at KPEQ, and around 13Z at KFST still seem reasonable. The main question will be the coverage of thunderstorms along/behind the front, which still looks to be greatest across far southeast New Mexico and the northern and eastern Permian Basin. Thus, have maintained TEMPOs for TSRA at KHOB and KMAF. Other sites will bear watching, especially if convection along the front is more robust. Low- end MVFR to possibly IFR ceilings/visibility are possible in the wake of the front, and while improvement is expected by mid- to late- morning Saturday, a bkn-ovc cloud deck around 3kft could stick around for much of the day. Winds will remain southeasterly this evening, and then become northeasterly. gusting to 20 to 25kt after the front passes late tonight, with gusts persisting through the end of the forecast period. && .PREV DISCUSSION... /ISSUED 230 PM CDT Fri May 29 2015/ DISCUSSION... Upper trough over the central plains states moves off to the east this afternoon. By Saturday an upper ridge will begin to build across the Western U.S. as the procession of upper troughs comes to an end. This will result in decreasing rain chances for the region as May comes to an end. This looks to be a significant change in the wet pattern of the past month... MAF has recorded 12 days with measurable rain so far this month with more rain expected tonight. This ridge will slowly shift east with temperatures increasing across the area into next week. This afternoon... tonight... and tomorrow looks to be the last good chance of rain in W TX and SE NM for the foreseeable future. May see some afternoon storms due to good moisture and daytime heating... and a little bit of a dryline across Brewster county. Good low level moisture still extends back across the Trans Pecos and SE NM. Rain chances increase tonight. A weak cold front is expected to sag down into the area overnight... storms look to develop along and behind the front spreading south tonight. The heaviest rain should be after midnight. A Flash Flood Watch remains in effect tonight and Saturday morning for the Northern and Eastern Permian Basin. Some of the model qpf shows heavy rain moving down across Gaines and Martin counties... others not as much. Have decided to expand the watch a little westward across these counties. For now have not including Ector or Midland counties in the FFA but this could change if conditions warrant. Also have to consider the threat of severe storms this afternoon and tonight. Most of CWA north of the Pecos River is included in the Day 1 slight risk. A shortwave may combine with decent low level moisture... good CAPE and shear to result in severe storms. Storms may begin with a hail threat then transition to strong wind and heavy rain overnight. However believe threat of heavy rain greater than threat of severe wx. With less rain and clouds around... will have more sunshine. This will result in warmer temperatures. Highs in the 90s return to the area early next week and continue through the end of the week. In the extended the forecast drys out with rain becoming much more spotty. A persistent surface trough hangs around the region most of next week. This trough and the higher elevations may be enough to fire off a few storms but coverage will be low. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...FLASH FLOOD WATCH from 10 PM CDT this evening through Saturday afternoon FOR THE FOLLOWING ZONES... Borden...Dawson... Gaines...Glasscock...Howard...Martin...Mitchell...Reagan... Scurry. && $$ Follow us on Facebook and Twitter at: http://facebook.com/NWSMidland http://twitter.com/NWSMidland Check us out on the internet at: http://weather.gov/midland