Area Forecast Discussion
Issued by NWS Mobile, AL
Issued by NWS Mobile, AL
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574 FXUS64 KMOB 010750 AFDMOB Area Forecast Discussion National Weather Service Mobile AL 250 AM CDT Sat Jun 1 2024 ...New NEAR TERM, SHORT TERM, LONG TERM, MARINE... .NEAR TERM... (Now through Saturday night) Issued at 250 AM CDT Sat Jun 1 2024 Thunderstorms will continue to quickly increase through the early morning hours in response to an approaching shortwave trough. We are becoming increasingly concerned with the threat for flash flooding, especially across coastal AL and the western FL Panhandle as we go through the morning into the afternoon hours. Latest mesoanalysis indicates SBCAPE of 4000 J/kg sitting just offshore of the coast with 2000-3000 J/kg already nosing into the southern third of the area. SBCAPE drops off to less than 500 J/kg across far inland portions of the forecast area. As deep layer lift increases early this morning, thunderstorms will continue to develop across the region, becoming most focused along this coastal instability gradient. These storms will be very efficient rain producers given precipitable waters of 1.8-2" and deep layer moisture convergence being centered right over the aforementioned instability boundary. The consensus of the hi-res guidance paints a corridor of very heavy rainfall across the southern third of the area with rain totals potentially approaching 6-8" in a few areas. Given these signals, we have issued a Flood Watch for coastal AL and the western FL Panhandle through this afternoon. If these higher totals occur, they will do so over a relatively short period of time which will further increase the flood threat, especially in the urban and poor drainage areas. We also cannot rule out isolated instances of flooding elsewhere across the area given the widespread nature of the storms and the highly efficient rain rates. In addition to the flood threat, there is a low end severe threat given effective deep layer shear around 30 kt. Hodographs from KMOB radar VAD wind profile are curved which has allowed for a mixed mode of multicells and supercell structures. Add in the potential for water loading and there is a threat for localized damaging wind gusts. It`s possible that the morning convection eventually consolidates and pushes offshore by late morning or midday, leaving storms chances more uncertain for the afternoon. Deep layer forcing will also begin to diminish in the afternoon. Therefore, rain chances will not be as high as in the morning, but scattered to numerous storms are still likely. Forcing becomes more subtle tonight, but given the presence of sufficient instability and plentiful moisture, isolated to scattered storms will remain in the forecast. However, these storms will not carry the same severe/flood threat we are seeing this morning. 34/JFB && .SHORT & LONG TERM... (Sunday through Friday) Issued at 250 AM CDT Sat Jun 1 2024 It now appears that we will be in the wake of better deep layer forcing on Sunday which will result in a decrease in rain chances. Scattered diurnal thunderstorms are still expected in the afternoon. We will trend drier early to mid week as shortwave ridging moves across the region. There will still be a daily chance of isolated, afternoon storms. A more amplified pattern will develop by Thu-Fri as strong upper ridging builds over northern Mexico into the southwestern states. Meanwhile, a large downstream trough will amplify and be centered over the Great Lakes. This places our region in northwest upper flow and this will likely push a front down into our area for the end of the week. There are timing uncertainties with this, but this boundary will likely enhance rain chances at some point in the Thu-Fri time frame. Temperatures will remain near or slightly above normal through the period. && .MARINE... Issued at 250 AM CDT Sat Jun 1 2024 Strong storms will expand in coverage across the marine area this morning. These storms will be capable of producing strong wind gusts in excess of 34 kt and potential waterspouts. Storms will likely decrease in coverage by late afternoon into tonight, but isolated to scattered storms will remain possible through Sunday. Outside of storms, south to southeast winds of 15-20 kt will persist today, decreasing late today into tonight. Light onshore flow is then expected to persist over the next several days. Seas will average 3-5 ft over the open Gulf waters today, with seas gradually subsiding through the end of the weekend. 34/JFB && .MOB WATCHES/WARNINGS/ADVISORIES... AL...Flood Watch through this afternoon for ALZ261>266. High Rip Current Risk from 7 AM CDT this morning through late Sunday night for ALZ265-266. FL...Flood Watch through this afternoon for FLZ201>206. High Rip Current Risk from 7 AM CDT this 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