Skinny The area of showers and thunderstorms in the southwest Gulf (red "swirly" L, in the second graphic below) has moved little since Sunday, but is expected to begin a northward "drift" overnight into Tuesday. At the same time, an upper level disturbance centered over southern California (base of the yellow curved line) will move steadily into Arizona Tuesday, and New Mexico Wednesday. Southwesterly steering flow ahead of this system will reach most of Texas by late Tuesday and Wednesday, and ultimately "pick up" the tropical disturbance and move its energy northward through the western Gulf by mid week. The remaining questions are: Will the surface system develop? Where will the primary impacts be? The combination of a disorganized system "lifting" into an area of moderate to strong atmospheric wind shear make the coming environment hostile to significant development.  That same shear and steering pattern suggests that heaviest rainfall - several inches or more - favors the Gulf waters vs. inland, populated locations of the Rio Grande Valley. By Thursday, and into the weekend and beyond, hot, rain-free weather returns.  Based on all of these factors, there is zero chance of a repeat of June 2018. However, there should be enough "forcing" to provide hopeful - and welcome - rainfall to at least the lower Valley (along and east of US 77/IH 69E, including Brownsville, Harlingen, and Raymondville) with the majority of the precipitation occurring Tuesday, perhaps continuing into Tuesday night and Wednesday but with much uncertainty as to where the additional rain may fall. Confidence is fairly high that the mid and upper Valley to the ranchlands will be largely rain-free most, if not all, of Wednesday.  Note that the lower and parts of the mid Valley are abnormally dry, but on the edge of moderate drought.  We are hopeful that this rain will put a (temporary) dent in the drying, but longer range forecast into mid June suggest drying will quickly return for many.   What to Watch For/Potential Impacts/Actions Rainfall Welcome rain is the main storyline.  As the graphic below shows, 1 to 1.5" is expected toward the coast, with 0.5 to 1" a bit farther inland, through Wednesday Prime time for rain will be on Tuesday.  Timing favors pre-dawn to early afternoon near the coast, and late morning through mid to late afternoon inland (i.e. McAllen/Edinburg/points west). Potential for rain along/east of US 77 continues into Wednesday, but there are equal chances that these areas could see much less at that time as seeing a "second round" Locally 2 to 3+ inches of rain may cause 1 to 2 feet of water depth in poor drainage locations, favoring locations along/east of US 77/IH 69E To be safe, drainage ditch clearing should be completed this evening (Monday).  Tides/Surf/Currents Some increase in easterly swell is expected beginning late tonight and continuing through Tuesday night. Rip currents may become more intense Tuesday. The increased swell may produce tidal run-up toward the dunes, beginning Tuesday evening and peaking at high tide (8-9 AM or so) Wednesday morning on South Padre Island Building surf and waves, with a south to north longshore current, is expected to begin Tuesday night and peak Wednesday into Thursday.  Poor to average swimmers may wish to stay in shallow water or out of the surf altogether from late Tuesday through Wednesday. Boating/fishing for small craft will become difficult Tuesday afternoon, and continue through at least Wednesday.  Those unsure of navigation may want to postpone trips during those times.  Outlook For the end of the week, next weekend, and beyond, signs are building for the first onset of the "La Canicula" pattern of strong atmospheric high pressure centered over west Texas/southeast New Mexico and northern Mexico (Chihuahua State). Should this develop, triple-digit heat will occur for much of the Valley and Deep S. Texas.  Initial high surface humidity could bring heat stress situations as "feels like" temperatures could exceed 110 in many areas each afternoon beginning Friday and peaking over the weekend.