Area Forecast Discussion
Issued by NWS Melbourne, FL
Issued by NWS Melbourne, FL
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213 FXUS62 KMLB 160009 AFDMLB Area Forecast Discussion National Weather Service Melbourne FL 809 PM EDT Mon Jul 15 2024 ...New AVIATION... .AVIATION... (00Z TAFs) Issued at 809 PM EDT Mon Jul 15 2024 Storms have largely diminished across the interior, leaving some lingering light debris cloud rainfall across the I-4 corridor this evening. Some embedded lightning strikes from this activity is still possible through 02Z. Localized moderate rain may produce visibility to 3-5SM, but otherwise VFR conditions generally expected, with visibility 6SM or greater. Similar setup tomorrow, with drier air near to south of KMLB and faster inland movement of the east coast sea breeze keeping rain chances limited from KMLB-KSUA. Isolated showers and storms may develop near KTIX-KDAB as east coast sea breeze forms early afternoon, but greatest convective coverage will be across inland TAF sites, around 19-00Z, as sea breeze moves inland and where boundary interactions are more likely. Have VCTS wording for now to cover this potential, but tempo groups will again likely need to be added with the next TAF package. Winds generally light and variable overnight, becoming southerly around 5-6 knots in the morning, and then E/SE 8-10 knots as the sea breeze develops and moves inland during the afternoon. && .PREVIOUS DISCUSSION... Issued at 223 PM EDT Mon Jul 15 2024 KEY MESSAGES: - Temperatures turn hotter through the work week. There is an increasing risk of heat-related illness for those without access to proper hydration and cooling later this week. - The highest chances (40-70%) for storms through midweek will continue to focus over the Interstate 4 corridor. Gusty winds and locally heavy rain to accompany the strongest storms. - Storm chances increase again for much of East Central Florida by the weekend. ---------Synoptic Overview---------- A rather stagnant upper-air pattern is forecast over North America and the W Atlantic over the next week, characterized by ridging over the Western U.S., a trough developing over the nation`s mid-section, and additional ridging from the East Coast well into the Atlantic Basin. Near the surface, an axis of high pressure will move little for the next few days as it holds very close to Central Florida. MIMIC-TPW satellite data shows a ribbon of higher atmospheric moisture slowly lifting into N Florida as drier air attempts to nose in from the Atlantic. Ensemble guidance continues to show this drier air pushing westward over the state during the middle of the week. By late this week and through the weekend, PW (total moisture) values are modeled to return to near or just above normal. H85 temperatures will continue to run near the max moving climatological average for mid-July (~ +19C), leading to continued above-normal temperatures through at least Saturday. The potential is increasing for more widespread impacts from heat late this week as the hot temperatures combine with additional humidity. -----Sensible Weather & Impacts----- Through Tonight... As suspected, we have quite a moisture gradient today as some drier air tries to poke into the Treasure Coast from the Atlantic. Above- normal atmospheric moisture still exists along the I-4 corridor, however. Thus, we expect storm coverage to range from 50-70% near Orlando to Titusville and points northward, lessening to 20% for the Treasure Coast beaches. Storms firing up now on the sea breeze east of Orlando will push/develop toward the interior/Orlando area along propagating outflows, culminating with a collision with the Gulf breeze by early evening. The primary hazards from today`s storms: gusty winds (10-15% chance of 40-50 MPH), heavy rain leading to localized urban flooding, and frequent lightning strikes. Storms will diminish by mid/late evening with clearing skies overnight. Lows will fall into the mid/upper 70s. Tuesday - Thursday... Guidance has struggled some with progression of the dry air on our doorstep through midweek, now delaying its progression by around a day. In essence, tomorrow`s forecast looks nearly identical to today with 20-40% coverage south of Melbourne increasing to 50-70% for the I-4 corridor. From Wednesday into Thursday, the drier air is forecast to push over a larger portion of the district. While it won`t completely stave off rain chances, it should lower our coverage with 40-50% storm chances near Orlando decreasing to 20-40% along the coast. High temperatures will turn a degree or two warmer, with widespread mid 90s over the interior and low 90s beachside. The hot temperatures may get offset by ever-so-slightly lower dew points, but in most cases, our heat indices will still top out from 100-107F each day. Friday - Next Monday... Indicators suggest that peak heat impacts during the next week will come on Friday and potentially even Saturday as dew points increase but rain coverage remains just low enough that we keep attaining widespread 93-96F high temps. Combined with lows in the mid/upper 70s, which are also above normal, the HeatRisk algorithm is locally Extreme for portions of Lake Co. and Greater Orlando, and Major for a sizable chunk of the district. Extreme HeatRisk typically only occurs during rarer episodes of long-duration extreme heat with little to no overnight relief. Heat indices are now forecast to reach 105-110F, which may necessitate advisories in future forecasts if these trends hold. The pocket of drier air aloft will be gradually replaced by deeper moisture from the tropics as we move into the weekend. Guidance continues to highlight a weak easterly wave moving toward the state by Sunday or next Monday. Storm chances will ramp back up in response, with 50-70% coverage presently in our forecast. However, statistical guidance is already hinting at 80% chances over the interior next Sun/Mon. It is typically high-biased with rain chances, but the pattern does look increasingly unsettled. As storm chances build Sun/Mon, high temperatures are forecast to dip at least a couple degrees. && .MARINE... Issued at 223 PM EDT Mon Jul 15 2024 Boating conditions remain favorable over the next few days. As high pressure holds sway, light southerly winds at night turn SE during the day, increasing to 10-15 KT, especially near the coast with the sea breeze. There is a 20-40% chance for showers and isolated storms, primarily during the overnight and morning hours. Seas generally 2-3 FT, occasionally up to 4 FT beyond 40 NM. && .PRELIMINARY POINT TEMPS/POPS... DAB 76 93 75 94 / 40 60 10 50 MCO 76 95 76 96 / 50 70 20 40 MLB 76 90 76 91 / 20 30 10 20 VRB 76 92 75 92 / 10 20 0 20 LEE 77 95 77 94 / 40 70 30 60 SFB 76 95 76 95 / 50 70 20 50 ORL 77 95 77 95 / 50 70 20 40 FPR 76 92 75 91 / 10 20 0 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ DISCUSSION...Heil AVIATION...Weitlich