479 FXUS64 KMOB 302252 CCA AFDMOB Area Forecast Discussion...Correction to Near Term National Weather Service Mobile AL 404 PM CST Thu Dec 30 2021 .NEAR TERM UPDATE /Now Through Friday/...Tonight through Friday, our region remains in southwest flow aloft as our region remains on the western periphery of ridging that continues to stretch north along the East Coast. At the surface, ridging continues to nose into our region from the east, with the ridging stretching west over the Gulf of Mexico through the period. This results in a general south- southwest low-level flow over the forecast area through the period. Given this pattern the air remains nice and moist through Friday, and more prominent ridging on Friday will also keep temps nice and warm. In terms of sensible weather, conditions are expected to remain mainly dry tonight through Friday although a few very isolated light showers cannot be ruled out. Guidance suggests winds easing as any residual precipitation moves off to the east. With this, fog development is a concern for tonight. Currently there is a Dense Fog Advisory in effect for Coastal Mobile and Baldwin Counties in Alabama, and Coastal Escambia, Santa Rosa, and Okaloosa counties in Florida beginning at 10PM CST. Outside of this, fog is expected to move inland through the night with areas of fog (some locally dense) expected generally along and south of the Highway 84 corridor, and patchy fog (some locally dense) north of Highway 84. There is a bit of uncertainty on how widespread dense fog will be outside of the Dense Fog Advisory area, but depending on how trends play out it may be needed a bit further inland. Trends will be monitored and updated. As we remain in a warm and moist airmass through the near term, temperatures through the period remain anomalously warm. Lows tonight continue to generally be in the upper 60s to low 70s across the area. Any fog development along with mostly cloudy skies will help to keep temps on the warmer side. On Friday, not to sound like a broken record, but more records will likely be broken, as if we have not broken enough over the last couple days. Highs on Friday will likely be the warmest day on record in the month of December across the CWA with mainly low/mid 80s expected with some spots reaching the upper 80s. Lastly, a High rip current risk remains in effect through the period. JEH/88 && .SHORT TERM /Friday night Through Sunday night/...Strong southerly flow ahead of an approaching positively tilted upper level trough will continue to advect abundant low level moisture across the region Friday night. Very warm and humid conditions will persist with low temperatures remaining in the upper 60s interior to lower 70s along the coast. Weak isentropic ascent within the moistening low levels will likely support the development of isolated to scattered showers overnight across much of the area. Another concern will be redeveloping sea fog Friday evening that will continue through Saturday morning. Dense fog is likely again to form near the coast and over bays and sounds as low 70s dewpoints overspread lower to middle 60s water temperatures. We will wait until tomorrow to reanalyze the specifics, but it does appear that another marine/coastal dense fog advisory will be needed. The fog potential may again develop Saturday evening but there is more uncertainty at this time. There still remains some disagreement with model timing and intensity regarding the handling of the approaching upper trough and associated strong cold front. It appears that much of the guidance has slowed and the frontal passage looks to occur from early predawn Sunday across western sections and early Sunday afternoon across the east. The latest guidance suggests that the positive trough begins to take on a more neutral tilt orientation as it passes through the area. This may result in an uptick in severe storm potential from Saturday night through early Sunday afternoon. At this time, it appears that there will likely be enough large scale forcing along the front to support a developing squall-line that will move into the western portions of our area later Saturday night and then to roughly the I-65 corridor by Sunday morning. Again, initially the best lift associated with the upper trough and right entrance region of a broad 140kt+ upper jet is aligned right along the front. This should limit prefrontal convection across the open warm sector initially. As the trough begins to rotate through and becomes increasingly neutrally tilted, there is some potential for prefrontal convection. There still remains uncertainty as to the exact storm mode, but this is our best estimate at this time. Abundant deep layer shear and sufficient instability should support the potential for some severe storms. Since there still remains some uncertainty regarding storm mode, it is still a bit too soon to pin down the greatest severe weather hazards. This will hopefully come into clearer focus as we get closer to the event and model differences get resolved. Behind the strong cold front, much colder temperatures will advect into the area on strong northwest winds. Temperatures will likely fall after the frontal passage later on Sunday. Strong cold advection will result in cold low temperatures by Monday morning which will be a stark change from the warm temperatures as of late. Lows will range from the middle 20s to the lower 30s along the coast. /JLH && .EXTENDED TERM /Monday Through Thursday/...Weak upper ridging over the Plains shifts east through mid week, with surface high pressure that had moved over the Plains quickly moving east, to off the East Coast by Tuesday night. With a surface ridge stretching southwest over the Southeast, strong northerly winds shift to easterly Tuesday into Tuesday night. With the weak ridging bringing an increase in upper subsidence, temperatures well below seasonal norms Monday rise to around normal Tuesday. A shallow upper trough replaces the weak ridge over the Southeast Wednesday into Thursday, with the surface ridge weakening and shifting south to over the northern Gulf coast, returning southerly, albeit weak, flow to the Southeast. With weak onshore flow Wednesday through Thursday, moisture levels increase slowly, with guidance advertising precipitable h20 values rising from around 0.2" Monday to around 1.0" by Thursday. An upper level shortwave moves through the shallow upper trough over the Southeast Wednesday through Thursday, bringing a return of rain to the forecast area. With the weak nature of the both the passing shortwave and moisture return, rain chances will be on the low side, with slight chance to chance PoPs before a cold front moves across the forecast area Thursday night. Guidance is inconsistent with the southerly flow Wednesday on, with the operational ECMWF a bit stronger. The result is a bit wetter and warmer forecast as compared the GFS. Both are advertising above normal temperatures for Wednesday through Thursday, just more so with the ECMWF. For this portion of the forecast, have went with a blend, with the result being temperatures about 5 degrees above seasonal norms for the latter half of the Extended. /16 && .MARINE...A brief weakening in northeasterly to northerly winds today will increase back to Small Craft conditions through tonight as a surface low continues east across the central Gulf. Seas will remain elevated through the weekend before slowly subsiding through Tuesday, and then slowly increase again going into mid-week. Light to moderate winds will remain out of the northeast through the weekend before turning east then south-southeast by Tuesday. Wind speeds begin to pick back up by this time and Small Craft Exercise Caution conditions are possible again by this time. Conditions will continue to be monitored and updated as needed. JEH/88 && .PRELIMINARY POINT TEMPS/POPS... Mobile 68 82 71 81 69 69 29 52 / 10 10 20 50 80 50 0 0 Pensacola 70 82 71 81 71 73 34 54 / 20 20 20 30 70 70 0 0 Destin 70 80 73 80 72 76 38 56 / 20 30 30 20 70 80 10 0 Evergreen 68 86 69 85 68 71 29 54 / 20 10 20 50 90 60 0 0 Waynesboro 67 81 67 79 56 56 26 49 / 10 10 10 80 90 50 0 0 Camden 66 81 67 82 63 63 28 50 / 10 20 10 60 90 60 0 0 Crestview 69 83 70 80 71 75 31 54 / 20 20 30 30 70 80 10 0 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...High Rip Current Risk through Sunday morning for ALZ265-266. Dense Fog Advisory from 10 PM this evening to 11 AM CST Friday for ALZ265-266. FL...High Rip Current Risk through Sunday morning for FLZ202-204-206. Dense Fog Advisory from 10 PM this evening to 11 AM CST Friday for FLZ202-204-206. MS...None. GM...Dense Fog Advisory until 11 AM CST Friday for GMZ630>636-650-655. && $$ This product is also available on the web at: http://weather.gov/mob