559 FXUS64 KMOB 231632 AAA AFDMOB Area Forecast Discussion...UPDATED National Weather Service Mobile AL 1132 AM CDT Sun Jun 23 2019 .DISCUSSION...See updated information for land areas below. && .UPDATE...Shortwave ridging aloft is shifting eastward across southwest/south central AL and the western FL panhandle this morning, while southwesterly flow aloft is gradually spreading into LA/MS ahead of a broad upper level trough over the Plains states. A shortwave impulse embedded within the southwesterly mid level flow will lift northeastward toward southeast MS and interior southwest AL this afternoon. Ascent associated with this feature will interact with a moist (precipitable water values around 1.8") and moderately unstable airmass (MLCAPE values around 2500 J/KG) to aid in the development of scattered showers and thunderstorms across portions of southeast MS and interior southwest AL this afternoon. High resolution convection allowing models have been consistent in developing storms across this portion of our CWA, so we have increased POPs generally along and west of a Camden to Mobile line this afternoon. Our wet microburst assessment does show a favorable potential for strong to locally damaging winds with any storm that develops across our western zones this afternoon, and we have kept mention in the Hazardous Weather Outlook product. We also cannot rule out an isolated shower or storm over portions of south central AL (near Crenshaw/ Covington counties) in the vicinity of a weak surface boundary on the southwestern periphery of a ridge located over the eastern CONUS. Otherwise, temperatures look on track to reach into the lower to mid 90s over interior areas, and around 90 near the beaches. Max heat indices will range between 100-105 this afternoon. Local beach reports from lifeguard partners indicate that rip currents are most frequent over the FL panhandle beaches (especially heading toward Destin) with the persistent southwesterly flow and swell. We have lowered the rip current risk to MODERATE over the AL beaches, while keeping the HIGH risk over the FL panhandle beaches. /21 && .PREV DISCUSSION... /issued 609 AM CDT Sun Jun 23 2019/ DISCUSSION...Updated for latest aviation discussion below. AVIATION... 12Z issuance...Patchy fog across the area dissipates by mid morning hours. VFR conditions and generally light south to southwest winds expected through the forecast. A few isolated showers and storms will be possible over southeast Mississippi and southwest Alabama this afternoon and evening. Expect frequent lightning and gusty winds in addition to locally lower cigs/vis in and around the heavier storms. /49 PREV DISCUSSION... /issued 443 AM CDT Sun Jun 23 2019/ NEAR TERM /Now Through Sunday night/...A broad upper ridge builds into the eastern CONUS through the near term as an unseasonably deep longwave trough ejects from the Rockies eastward over the Great Plains. At the surface, high pressure centered over the Florida peninsula and eastern Gulf maintains a south to southwesterly low- level wind flow across the region. While the strongest upper divergence associated with the upstream trough occurs over the Mississippi River Valley to our west, minor height falls over the western half of the local area could provide enough of a weakness aloft for some isolated shower and thunderstorm development this afternoon and evening. This potential is only weakly supported in CAMs and SREF/HREF ensembles, likely due to a lack of forcing aside from diabatic heating. Given this uncertainty, decided to limited PoPs to slight chance over southeast Mississippi and interior southwest Alabama counties. With convection heavily dependent on daytime heating, expect activity to taper after sunset this evening, with a dry forecast for our area tonight. Meanwhile, a broken line of thunderstorms is expected to organize well to our northwest over the Ark-La-Tex region extending northeast into western Tennessee. This line pushes southeast through central Mississippi during the overnight hours tonight as it gradually weakens. Even if convection dissipates before reaching the local area (as some guidance suggests), the remnant outflow boundary could serve as a focus for active weather in our area on Monday. See the Short Term section below for more details. /49 SHORT TERM /Monday Through Tuesday night/...An upper ridge over the Eastern Seaboard and eastern Gulf partially moves off into the western Atlantic through Monday night in response to an upper trof over the central states which takes on a negative tilt while moving off to the Great Lakes region. Scattered showers and storms (possibly a broken line of convection) are expected to have developed west of the forecast area Sunday night in response to a series of shortwaves moving through the base of the upper trof. The forecast for Monday is a bit complex due to a weak outflow boundary which is expected to have moved into the forecast area from prior convection. As the upper trof ejects off towards the Great Lakes, the scattered showers and storms advance into the area along with potential additional convective development along the weak remnant outflow boundary. Convective coverage is expected to be better overall over the western portion of the area compared to the southeastern portion where lingering subsidence effects with the upper ridge will be present, but this will have to be monitored. Have for now gone with good chance pops over the western portion which taper to slight chance pops over the southeast portion. A broad upper trof pattern forms over much of the eastern states Tuesday into Tuesday night while the axis of an upper ridge persists just off the east coast and into the eastern Gulf. Another upper ridge also advances eastward partially into the central states and begins to the amplify during this time frame. A series of shortwaves are expected to continue to move across the forecast area and expect isolated to scattered convective development by Tuesday afternoon with some convection lingering into the evening hours. Shear values will be low through the period with 0-6 km bulk shear values typically less than 20 knots. MLCAPE values of 1500-2500 J/kg develop on Monday then lower values are expected on Tuesday (1000-1500 J/kg) as somewhat drier lower level (900-800 mb) air is advected into the region. May see some strong storms develop on Monday given the higher instability, but otherwise severe storm development is not expected through Tuesday night. Highs each day will be in the lower 90s. Heat index values of 100 to 105 are expected on Monday with somewhat lower values expected on Tuesday. Overnight lows generally range from the lower 70s inland to the mid 70s at the coast. A high risk of rip currents is expected on Monday followed by a moderate risk on Tuesday. /29 LONG TERM /Wednesday Through Saturday/...An upper ridge builds over the central states while a weak upper trof develops over the region and is expected to linger through Saturday. A surface ridge will be located just west of the forecast area on Wednesday into Thursday which results in a seasonably unusual northerly surface flow over the forecast area. A weak inverted surface trof continues to be expected to meanwhile develop near the Florida peninsula/Florida Straits which then progresses slowly westward across the northern Gulf. This results in an easterly surface flow developing over the forecast area on Friday which becomes southeast on Saturday and brings increasing deep layer moisture into the region. Have gone with mostly slight chance pops for Wednesday then chance pops follow for Thursday as the upper trof developing over the area provides for a better convective environment despite a northerly surface flow. Chance to good chance pops follow for Friday and Saturday as deep layer moisture improves along with the inverted surface trof passing across the area. Highs each day will be mostly in the lower 90s and overnight lows range from around 70 inland to the lower/mid 70s closer to the coast. /29 MARINE...Surface high pressure gradually pushes west from the eastern Gulf into the north central Gulf and then lower Mississippi River Valley through the early part of this week. As a result, light to occasionally moderate southwest winds continue through Monday before gradually veering to westerly and then northerly by Wednesday/Thursday. No significant shower or thunderstorm activity is expected over the marine area until late in the week. /49 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...None. FL...High Rip Current Risk through Tuesday morning for FLZ202-204-206. MS...None. GM...None. && $$ This product is also available on the web at: http://weather.gov/mob