490 FXUS64 KMOB 182028 AFDMOB Area Forecast Discussion National Weather Service Mobile AL 328 PM CDT Sat Jul 18 2020 .NEAR TERM UPDATE /Now Through Sunday/...A broad deep layer ridge of high pressure continues to extend across the Tennessee Valley and southeastern states this afternoon. Visible satellite imagery shows a fairly extensive cumulus field across our region within the moist low levels of the atmosphere. Convergence along the seabreeze is allowing for the development of a few showers and thunderstorms near the coast. Isolated to locally scattered convection is expected to develop northward along the seabreeze boundary through the afternoon and will maintain POPs around 30% coverage into the interior northwest FL panhandle and adjacent portions of southwest/south central AL. Forecast soundings from the NAM/RAP indicate that MLCAPE values between 2000-3000 J/KG will be in place along southern portions of the CWA this afternoon, while DCAPE values may locally exceed 1000 J/KG. Isolated storm cells could still be capable of producing brief strong/gusty winds. Isolated cells may linger until around or shortly after sunset early this evening, before dry conditions are anticipated overnight. The exception could be the development of isolated showers near the immediate coast toward daybreak. Short range models continue to indicate a shortwave trough moving across the northern Gulf and adjacent southwest AL/southeast MS Sunday on the southern and southwestern periphery of the mid level ridge axis Sunday. Moisture associated with this feature may be a bit more enhanced across southern and southwestern portions of our forecast area Sunday, with precipitable water values projected to rise around or slightly above 2" over these areas. Convective coverage may be a little more enhanced over far southeast MS into far southwest AL along the seabreeze Sunday afternoon, and for now will raise POPs to 40-50% over the above mentioned areas, with 20-30% coverage further inland. The seasonably hot and humid conditions will otherwise continue through Sunday. Lows tonight range in the lower to mid 70s inland and in the upper 70s to around 80 near the coast and beaches. Highs Sunday should once again range in the lower to mid 90s over interior portions of the region and around 90 degrees near the immediate coast and beaches. Maximum heat indices continue to range between 100-105 degrees. /21 && .SHORT TERM /Sunday night Through Tuesday night/...Strong upper level high pressure centered over the Tennessee River Valley and Southeast remains in place, weakening a bit as a series of upper level shortwave systems pass to the north and south though the period. A surface ridge continues to stretch west over the Southeast through the period, bringing general southeasterly flow to the forecast area and nearby. Guidance is advertising moisture levels remaining at or above seasonal norms, ranging from 1.5"-2". With the upper ridge remaining in control through Tuesday, below seasonal chances of rain are expected each day, with isolated to scattered afternoon showers and thunderstorms. A few may become strong to severe, with afternoon MLCapes topping out around 2000 J/kg and DCape values rising into the 900-1200 J/kg range each day. Add in some dry layers above 500mb, and we will have to monitor for damaging downburst winds. Subsidence from the persistent upper ridge and high moisture levels will continue to bring temperatures generally above seasonal norms. High temperatures ranging from the mid to upper 90s inland, around 90 along the coast are expected. Low temperatures in the low to mid 70s inland, upper 70s along the coast are expected. /16 && .EXTENDED TERM /Wednesday Through Saturday/...The upper ridge over the Southeast shifts west to over the eastern Plains/Mississippi River Valley and builds as an upper trough develops off the East Coast. Wednesday through Thursday, guidance continues to advertise an upper level trough moving west over the Gulf of Mexico, on the southern periphery of the upper ridge. Today's guidance is advertising a bit more southerly track of the trough, with the GFS more so than the ECMWF. Have shifted the higher likely PoPs south as a result, placing them mainly over the open Gulf waters. Have continued to generally place the higher PoPs over the southern portions of the forecast area, closer to the passing system. Have also continued to keep the lower daytime temperatures for Wednesday and Thursday closer to the coast, with higher cloud coverage and weaker subsidence from the passing upper trough. High temperatures ranging from around 90 to the low 90s expected south of Highway 84, around to upper along and north each day. Lows remains pretty much status quo Wednesday night, with low to mid 70s expected inland, upper 70s along the coast. Thursday night through Saturday, the ECMWF builds the upper high farther east (along the east side the Mississippi River Valley) than GFS (over the eastern Plains). With the 00z ECMWF ensembles and 12z GFS ensembles advertising an in-between solutions, have went with a blended approach. Temperatures above seasonal norms due to the presence of the building upper ridge nearby. High temperatures ranging from the mid to upper 90s, and around 90 along the coast are expected, with low temperatures in the low to mid 70s inland, upper 70s along the coast. Have went around seasonal with the PoPs, with an upper level weakness present near the forecast area in either solution. /16 && .MARINE...No impacts forecast except winds and waves higher near isolated to scattered thunderstorms. /21 && .PRELIMINARY POINT TEMPS/POPS... Mobile 74 93 72 91 74 93 75 92 / 10 50 10 30 10 30 10 50 Pensacola 76 92 76 92 76 92 78 90 / 10 30 10 20 10 20 10 50 Destin 78 89 78 92 78 91 79 88 / 10 20 10 20 10 20 10 50 Evergreen 73 95 72 95 71 95 74 94 / 10 30 10 40 20 50 20 40 Waynesboro 72 93 72 93 71 94 72 92 / 10 20 10 40 20 30 20 40 Camden 73 95 73 95 72 94 74 93 / 10 20 10 40 20 50 20 40 Crestview 73 94 71 96 70 95 74 92 / 10 30 10 40 20 40 10 50 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...None. FL...None. MS...None. GM...None. && $$ This product is also available on the web at: http://weather.gov/mob