Scientific Forecaster Discussion
000 FXUS64 KLCH 280956 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 456 AM CDT Wed Jun 28 2017 .DISCUSSION... Latest upper air analysis/water vapor satellite imagery depicted an upper level trof over E TX and into the NW Gulf. SFC to H7 analysis revealed an inverted trof axis stretching from SC LA across the NW Gulf to near the TX/MX border. Convection has blossomed over the coastal waters within the past couple of hours, with some of this activity reaching coastal SE TX/SRN LA before dissipating as it progresses farther inland. Upper trof over E TX is forecast to remain quasi-stationary today while the low to mid level inverted trof axis sharpens a bit and becomes re-oriented in a more E-W manner over the Gulf waters and pushes inland tonight. Both the GFS/ECMWF maintain something of an E-W oriented upper jet (50-60KT) over the central/eastern Gulf coast states, placing much of coastal TX/LA and the adjacent Gulf waters in a RRQ. The corresponding increase in low level wind fields is evident in a 20-30KT LLJ. While neither of these kinematic features is overly impressive in magnitude, any lift added to an already moisture laden (PWAT AOA 2") and unstable airmass will only serve to enhance convective coverage. Thus, anticipate a generally wet next 48 hrs or so from roughly the I-10 corridor southward, with an attendant risk of locally heavy rainfall given efficient rain producing convection. Have mentioned this potential in the grids and will also address in the HWO. Low/mid level trof axis and its associated MSTR pool will continue to lift off TWD the NE and begin to pull away from the area THU night, replaced by a low/mid level ridge and relatively drier air building into the northern Gulf. Rain chances will begin to decline then virtually disappear for the weekend and into early next week. 13 && .MARINE... An upper level trof of low pressure over the northwest Gulf coupled with a surface trough of low pressure along the Texas coast will result in modest east to southeast winds and numerous showers and thunderstorms through Thursday. Have headlined exercise caution today for 15-20KT winds over the Gulf waters, and this may need extending further in time. Rain chances will decrease as these features lift to the northeast and away from the region by Friday, with light to modest south winds prevailing around high pressure ridging west across the Gulf. 13 && .PRELIMINARY POINT TEMPS/POPS... AEX 88 72 85 74 / 30 30 50 20 LCH 85 76 85 79 / 60 70 80 30 LFT 84 73 83 76 / 60 60 80 30 BPT 85 75 85 78 / 60 70 80 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...Small Craft Exercise Caution through this evening for GMZ450-452- 455-470-472-475.