707 FXUS64 KBRO 202000 AFDBRO Area Forecast Discussion National Weather Service Brownsville TX 300 PM CDT Mon Apr 20 2020 .SHORT TERM (Now through Tuesday night): High pressure to the north will shift east, and lower pressure will develop over West Texas in the short term. Weak winds will stabilize and slowly strengthen to moderate southeast tonight and Tuesday. Mid level flow will be zonal during the period and shouldn't be much of a factor. Stabilization of onshore winds will support increasing low level moisture and relative humidity values from east to west, and will also support increasing cloud cover. Patchy fog will develop overnight into Tuesday morning across the nearshore waters, the Laguna Madre, and portions of the CWA, especially eastern sections. Southeast winds will be slightly stronger tonight compared to last night, and therefore may be enough to preclude another round of dense fog. Thus, am not forecasting dense fog over land areas tonight. Temperatures will continue above normal in the short term. Low temperatures in the 70s overnight and high temperatures in the 90s inland by day will be around five degrees above normal. Heat index values may poke above 100 degrees, up to 105 degrees, out west Tuesday afternoon. .LONG TERM (Wednesday through Monday): In general, well above normal temperatures and below normal precipitation will continue in the long-term period. A shortwave trough over the Southern/Central Plains will advance eastward through the day Wednesday. Its associated weak surface cold front will slowly sweep through the state and likely push through the Rio Grande Valley and Deep South Texas on Thursday morning. Although there might be an isolated shower or thunderstorm ahead of the front on Wednesday afternoon/evening across the northern Ranchlands, the bulk of the forcing for convection development will remain north of the area. Surface high pressure will quickly build in over northern Texas and move eastward over the Southern US by Thursday evening. Southeast winds will return by the overnight hours on Thursday or early Friday morning. Model guidance suggests Friday to be the warmest day of the week, especially for central and western parts of the CWA, as a dryline develops along the foothills of the Sierra Madre Orientals in the morning and pushes eastward through the day. Models have the dryline reaching near or just west of the I-69E corridor before retreating westward after peak heating. If this scenario plays out, high temperatures will reach the triple digits along/west of I-69E in the afternoon on Friday, with mid-upper 90s elsewhere (except for the immediate coast). The forecast becomes a little murky beyond Friday as forecast model solutions begin to diverge. Quasi-zonal flow aloft will continue through the remainder of the period. Another weak cold front will approach Deep South Texas Friday night into Saturday morning. The front is forecast to stall over or just north of the area late Saturday morning, perhaps sliding through late Saturday night or early Sunday morning. Temperatures may cool down back to near seasonal normal on Sunday if the front is able to push through. The front should quickly push back north as a warm front Monday morning, with above normal temperatures returning Monday afternoon. && .MARINE (Now through Tuesday night): Light to moderate southeast winds and low to moderate seas will prevail. Patchy marine fog will develop along the coast and across the Laguna Madre tonight and even Tuesday morning. Dense fog will be possible. Wednesday through Saturday night...Southeast winds are expected to increase, possibly to Small Craft Exercise Caution conditions, Wednesday afternoon ahead of an approaching weak cold front. The front is expected to pass over the lower Texas coastal waters Thursday morning. Light to moderate north/northeast winds on Thursday will quickly turn easterly/southeasterly by Thursday night. Generally favorable marine conditions will persist Thursday through Saturday. Winds and seas will increase again to exercise caution levels Saturday night into Sunday morning. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 73 85 74 89 / 0 0 0 10 BROWNSVILLE 73 89 75 90 / 0 10 0 10 HARLINGEN 72 91 75 94 / 0 10 10 10 MCALLEN 73 93 76 98 / 0 0 0 10 RIO GRANDE CITY 72 97 75 99 / 0 0 0 10 SOUTH PADRE ISLAND 73 81 75 81 / 0 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...None. GM...Dense Fog Advisory until 4 PM CDT this afternoon for GMZ130-132- 135-150-155. && $$ This product is also available on the web at: HTTP://WEATHER.GOV/RGV Short Term/Aviation...54-Miller Long Term...67-Mejia