Area Forecast Discussion
Issued by NWS Mobile, AL
Issued by NWS Mobile, AL
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848 FXUS64 KMOB 310947 AFDMOB Area Forecast Discussion National Weather Service Mobile AL 447 AM CDT Fri May 31 2024 ...New NEAR TERM, SHORT TERM, LONG TERM, MARINE... .NEAR TERM... (Now through Saturday) Issued at 445 AM CDT Fri May 31 2024 Weak upper level ridging remains in place over the state of Alabama early this morning while an upper level shortwave continues to slowly move across eastern Louisiana. A MCS, associated with the upper shortwave, is also moving across southeastern Louisiana and will continue to weaken as it pushes into southern portions of Mississippi thanks to the influence of the upper ridging. While the bulk of the convection is expected to dissipate before it moves into our area, we can`t rule out a few light showers in our far western zones around sunrise as the remnant outflow slides into the area. As we head into the rest of today, shortwave impulses will continue to move over the Lower Mississippi Valley with another MCS likely approaching from the west this afternoon. Given that we`ll still be under the influence of the ridging, we expect this system to weaken before it moves into our area (similar to this morning). There could be a few showers and storms that try to develop over southeast Mississippi or interior portions of the area where there could be lingering outflow boundaries, but otherwise most areas should remain dry today. Highs this afternoon will be rather warm with upper 80s and lower 90s expected across the area. Overnight lows tonight range from the middle 60s well inland to the middle 70s at the beaches. A more potent shortwave swings across the Lower Mississippi Valley Friday night and into the Southeast on Saturday, ultimately pushing the upper ridging east. This upper level support combined with better moisture return will result in an unsettled pattern towards the latter half of the period. Showers and storms will begin to increase in coverage late Friday night and into Saturday morning as a remnant outflow boundary pushes into the area from the west. Additional showers and storms are also expected to develop Saturday afternoon as another surface boundary nudges into the area and serves as a focus for convective development. While deep layer shear is expected to remain rather weak (around 20-30 knots) during this time, we could see some strong or perhaps severe storms develop on Saturday in the form of wet-microbursts. Gusty winds will be the primary concern with any stronger storms with hail being less likely given that storms will be water loaded. Storms will also be capable of producing high rainfall rates which could lead to some localized or nuisance type flooding especially given the slower storm motions. "Cooler" temperatures are expected on Saturday given the higher rain chances and cloud cover with highs likely topping out in the lower and middle 80s. On a beach related note, we expect the rip current risk to increase through the day today as southeasterly flow strengthens. RCMOS guidance suggests that a low risk of rip currents may linger this morning before quickly increasing to a moderate risk by this afternoon. Therefore, we have opted for a moderate risk at all area beaches today and a high risk for dangerous rip currents on Sunday. /14 && .SHORT & LONG TERM... (Saturday night through Thursday) Issued at 445 AM CDT Fri May 31 2024 A complex pattern with significant model differences make for an uncertain forecast for much of this period. Guidance begins to diverge as early as Saturday night in the wake of what will likely be numerous showers and thunderstorms during the day on Saturday. It`s possible that early day storms significantly stabilize the atmosphere for Saturday night. In addition, model guidance differs on if there will be additional shortwave/MCS activity moving in from the west or does shortwave ridging actually begin to build in the wake of the Saturday system. Overall guidance has not done well in this pattern back to our west over the past few days and that appears to persist for us. For now, will keep precip in the chance range Saturday night. Consensus guidance is as high as 60-70% for Sunday and this seems high given the aforementioned uncertainties. For now will go with 50-60%, mainly due to the possibility of another shortwave moving into the area and the presence of significant deep layer moisture and instability. However, further refinements to rain chances will need to be made as we get closer in time and Sunday could still end up drier than currently forecast. We transition to more of a diurnal pattern of isolated to scattered afternoon storms for early to mid next week as upper level forcing appears to be very subtle. By Thursday it appears that we start to get into the influence of upper level northwest flow as a strong upper ridge develops in the western states. There are significant disagreements in the guidance on exactly how strong/far west the ridge builds and how deep of a downstream trough will develop in response across the eastern states. There are too many unknowns so will keep low end chance POPs in for Thursday. Bottom line is there is a lot to iron out in this pattern and several adjustments will likely be needed as we go through time. Temperatures overall will remain near to slightly above normal through the period. 34/JFB && .MARINE... Issued at 445 AM CDT Fri May 31 2024 A light to moderate southeasterly flow is expected through much of the weekend, with a slight increase in winds on Saturday. Small Craft will likely need to exercise caution late Friday night into Saturday. By Sunday evening into the early part of next week, a lighter onshore flow returns to the marine area. Waves and seas increase over the weekend as well before subsiding early next week. /14 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...High Rip Current Risk from Saturday morning through late Sunday night for ALZ265-266. FL...High Rip Current Risk from Saturday morning through late Sunday night for FLZ202-204-206. MS...None. GM...None. && $$ This product is also available on the web at: www.weather.gov/mob