FXUS64 KMOB 250958 AFDMOB Area Forecast Discussion National Weather Service Mobile AL 458 AM CDT Sun Jul 25 2021 .NEAR TERM UPDATE /Now Through Monday/...Current temperatures are warm, generally around the mid 70s; although, a couple spots along the immediate coast were in the upper 70s to around 80 degrees. No showers or storms were observed on radar over the local area in the past hour or so. Although, a few showers/storms were seen moving over south-central Mississippi and into the boot of Louisiana. Most recently, a few showers have popped up over the Gulf waters east of the boot of Louisiana. Some reduction in visibility has also been observed from surface observations generally along and north of Highway 84, indicating the present of patchy fog. This will persist through the remainder of the overnight and into the early morning hours, but any fog is expected to then dissipate with the sunrise. An upper level ridge of high pressure will continue to build eastward from the southern high plains to the Mississippi and Tennessee Valley regions today while weak low level ridging noses westward across Georgia and Alabama. Short range model solutions remain in decent agreement with advecting a drier airmass into the western Florida Panhandle and south central Alabama this afternoon, with precipitable water values decreasing to between 1.3-1.6 inches across these areas. Higher moisture content will be located roughly along and west of the I-65 corridor, where precipitable water values will continue to range between 1.8-2.0 inches. We subsequently expect greater coverage of afternoon convection to be focused across southeast Mississippi and southwest Alabama this afternoon. There is even a good signal of locally numerous coverage of showers and storms in the vicinity of southern portions of southeast Mississippi, where we will carry likely PoPs during the afternoon. Model MLCAPE values range between 2500-3500 J/kg over the local area along and west of I-65. Depending on the model guidance, DCAPE ranges between 500-1000 J/kg and 1000-1200 J/kg. Therefore, a few strong storms are possible, but are expected to remain sub-severe. The main threats with any stronger storms will be frequent lightning, some gusty winds, and heavy rain. Meanwhile, an isolated storm or two cannot be ruled out over our eastern zones, thus will maintain PoPs around 20% across south central Alabama and the western Florida Panhandle. However, expect most places in this portion of the local area to remain dry. Isolated to scattered storms may linger across western portions of the forecast area through the early to mid evening hours before dissipating with the loss of daytime heating. A slightly drier airmass, along with increased subsidence, may extend across southern/coastal portions of the forecast area on Monday, while higher theta-e air will continue to extend across interior portions of southeast Mississippi and southwest/south central Alabama. Convective coverage may be more limited across the region on Monday, but will continue to carry chance PoPs over interior areas within the higher PWAT airmass. Additionally, we continue to monitor an area of low pressure off the east coast of Florida. Model guidance continues to suggest this will form a weak inverted trough over Florida and Georgia through the day on Monday. At this time, this feature looks to not have much of an effect on the local weather through the near term period. Hot and humid conditions will otherwise persist today and Monday, with high temperatures trending in the lower to mid 90s. Heat indices will also continue to top out in the 102-107 degree range over most areas, though a few locations could reach as high as 110 degrees. The majority of the region will remain just below Heat Advisory criteria, but those planning to spend extended periods of time outdoors should exercise caution. Drink plenty of fluids, stay out of the sun, and check up on relatives and neighbors. /21/26 && .SHORT TERM /Monday night Through Tuesday night/...The broad upper level ridge that had been over the southeastern states shifts west by Monday evening into Tuesday, with a slight weakness aloft then noted over the southeastern states through Tuesday night. Western portions of the forecast area may remain under the influence of the ridging aloft than the eastern half of the forecast area. At the surface, models are similar in showing an inverted trough moving west across the Gulf of Mexico during the short term period, with weak riding continuing over the interior of the southeastern states. The combination of this weak trough to the south and the weakness aloft over the area, along with a still very moist airmass (PWATs 1.8 to 2.o inches, will result in scattered to possibly numerous showers and thunderstorms on Tuesday. The convective pattern will be diurnal however, with diminishing coverage during the evening hours both Monday and Tuesday. Late night showers or storms should be very limited, with no real forcing noted. The heat and humidity continues during the short term period High temperatures on Tuesday will mainly be in the low to mid 90s across the entire area, with afternoon heat indices on Tuesday in the 103 to 107 degree range. Lows will continue to range from the mid 70s over interior areas to the upper 70s along the coast. /12 && .EXTENDED TERM /Wednesday Through Saturday/...An expansive mid and upper level ridge continues to amplify over the central and western portions of the CONUS on Wednesday before spreading to the south and east on Thursday. The ridge continues to elongate as it spreads toward the Southeast through early next weekend. Meanwhile, a trough generally remains draped across the East Coast with several shortwaves amplifying the flow throughout the week. Some of the model guidance hints at an upper low or weak inverted trough sliding west across the southern Gulf through the period. Locally, the area remains in a weakness aloft between the ridge to our west and trough to our northeast on Wednesday (and somewhat on Thursday) before the ridge spreads into the region late in the week. Winds aloft remain easterly to northeasterly at times through Saturday. At the surface, a ridge over the western Atlantic maintains its grip over the Southeast and northern Gulf through the period. A weak boundary/trough continues to drift south into the area on Wednesday before stalling and likely washing out on Thursday as it encounters the ridge nudging into the Gulf. This boundary/trough will provide focus for shower and storm activity on Wednesday and to a certain extent Thursday as well. Moisture continues to surge into the area ahead of the boundary with PWATs of 2.0-2.2+ inches on Wednesday and most of Thursday. Expect higher coverage of showers and storms in comparison to our typical summertime pattern on Wednesday given the forcing and moisture. Given that the boundary should be washing out on Thursday, opted to go with scattered coverage for communities well inland (north of Highway 84) with the higher coverage focused closer to the coast where the higher moisture content resides by Thursday afternoon. Coverage by Friday and Saturday should return closer to a normal summertime pattern given the lack of forcing and ridging moving closer to the region. POPs on both afternoons remain in the 30s & 40s. Heat stress will be a concern each day during the extended. Temperatures will top out in the low 90s on Wednesday due to the convective coverage with an increasing trend in high temperatures the next several days. Dewpoints remain in the mid to upper 70s each day. Expect widespread heat indices of 106-108° by Wednesday with heat indices of 107-109° by Thursday, Friday, and Saturday (a few spots may top out closer to 110°). If this heat index trend continues, we be looking at Heat Advisories at some point during the extended forecast. 07/mb && .MARINE...No impacts are expected through the period aside from higher winds and seas near isolated to scattered showers and storms. Through early this week, light to at times moderate north to northeast flow is anticipated from the late night through the morning hours with a shift to a southerly direction in the afternoon. West to southwest flow will then take hold by late week. Little change in seas is expected (1-2 feet). /26 && .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