741 FXUS62 KMLB 021110 AFDMLB Area Forecast Discussion National Weather Service Melbourne FL 710 AM EDT Mon Jun 2 2025 ...New AVIATION... .KEY MESSAGES... Issued at 140 AM EDT Mon Jun 2 2025 - Marginal Risk of severe storms this afternoon and evening for areas south of I-4, with a low chance (5-14%) of wind gusts of 60+ MPH and coin-sized hail. - Scattered to numerous storms through midweek, peaking along the Treasure Coast today and across all of East Central Florida Wednesday. Frequent lightning and localized flooding in urban or poorly drained areas are the primary hazards. - As patchy Saharan dust arrives and lingers later this week, storm chances dip closer to normal for early June. Increasing heat risk by the weekend, with highs in the low/mid 90s and peak heat indices near 105 F. && .PREVIOUS DISCUSSION... Issued at 140 AM EDT Mon Jun 2 2025 -----------Synoptic Overview----------- GOES WV imagery and the 02/00Z RAOB analysis reveal a deep trough over Quebec with its axis extending southward to Florida. On the southwest flank of the trough, a shortwave is diving through the Lower Mississippi Valley. Weak shortwave ridging resides ahead of this feature, generally over Florida early this morning. A diffuse frontal boundary and impressive moisture discontinuity remain situated over the Florida Peninsula. Over the next few days, ensemble guidance shows the shortwave drifting overhead and stalling as ridging builds north of Florida. Coincident jet stream diffluence near and to the east of the feature will place much of Florida in a zone of broad synoptic ascent. In response, members suggest the old surface boundary sharpens slightly and gradually lifts northward through the middle of the week, drawing the reservoir of anomalous tropical moisture back over Central Florida through at least Wednesday or Thursday. A weak surface low could develop along the boundary by Wednesday. This feature is forecast to lift north of Florida from late Thursday through the weekend. By Friday and Saturday, mid-level ridging is expected to take its place as a Saharan Air Layer (SAL) lifts from the Greater Antilles toward Florida. Moisture values are anticipated to fall to near or even slightly below normal, especially over the southern half of the state. Late next weekend, guidance shows a trough moving back into the Great Lakes causing a weakness in the ridge over Florida. Regardless, a surface high pressure axis should become centered near Central or South Florida late this week and through the weekend. 5 KFT temperatures are forecast to rise above normal beginning Wednesday through the end of the forecast period. -------Sensible Weather & Impacts------- Today - Tonight... The approaching disturbance and associated lift should be on our doorstep this afternoon into tonight. Its interaction with the sea breeze, a leftover surface trough, and high moisture necessitates 60- 80% coverage of showers and storms south of Kissimmee to Melbourne, decreasing to 20-50% along the I-4 corridor. The highest chance for showers and storms is from 2 PM until around midnight. Within the higher coverage area (southern half of the district), proximity soundings indicate a moderately unstable environment with slightly colder-than-normal mid-level temperatures and modest bulk shear. Expect prolific rainfall from storms, with at least a low (5-14%) chance for excessive rainfall amounts causing flooding in poorly drained and/or urban locales. While most spots will receive lesser amounts of up to 1-2", reasonable high-end rainfall amounts (10% chance of occurrence) are 3-5" today from southern Brevard and Osceola Counties southward. There is also a less than 15% chance for a few strong storms with wind gusts to around 60 mph and coin- sized hail. Seasonably warm to hot temps are forecast with the warmest readings (low 90s) from I-4 northward. Tuesday - Thursday... Remaining quite unsettled as the upper disturbance sharpens the old front and lifts it northward through Central Florida. Showers and storms remain in the forecast for much of the period. However, the highest chances for rain/storms (widespread 60-80%) appear to be on Wednesday as the boundary is passing overhead. While the threat of severe weather appears relatively low on Tue/Wed due to the nearly saturated column, a few gusty storms still cannot be ruled out. Additionally, the presence of a low-level boundary supports a non- zero risk for a brief tornado, though the threat remains low. Locally heavy rain from repeated storms continues to be a focus for this timeframe, with a continued low chance for some brief flooding of urban and poorly drained locations. As the boundary slowly shifts toward N Fla on Thursday, rain and storm chances subtly decrease for our southern communities, with 50- 70% coverage forecast from south to north. Drier air begins to filter in from the south as the SAL (Saharan Air Layer) impinges from the Bahamas. Any stronger storms that develop in this environment could produce strong outflow winds due to elevated downdraft CAPE (dCAPE) values. Due to the clouds and showers, most places will hold in the mid/upper 80s for highs each day. Friday - Next Weekend... The stubborn disturbance finally gets kicked north of here, leaving an axis of high pressure nearby through the weekend. Daily 40-60% chances for showers and storms continue, but these should be more of the typical summertime afternoon and evening variety. Less cloud cover, high dew points, and warm boundary-layer temps raise concern for excessive heat impacts this weekend. Currently, our forecast calls for low/mid 90s beginning Saturday, with peak heat indices of 100-105 deg F anticipated. && .MARINE... Issued at 140 AM EDT Mon Jun 2 2025 A weak, stalled front remains over the local Atlantic waters. Slowly, this front begins to retreat northward from late Tuesday into Wednesday before lifting out of the local area. Scattered to numerous showers and lightning storms are forecast through at least the middle of the week. High pressure then builds over the waters late this week and into next weekend. Generally light winds today should allow for a robust sea breeze along the coast. Winds freshen from the E 10-15 KT on Tuesday before shifting to the SE on Wednesday and Thursday. Seas 2-3 FT through Tuesday, then 2-4 FT Wed/Thu. && .AVIATION... (12Z TAFs) Issued at 710 AM EDT Mon Jun 2 2025 VFR conditions prevailing. Showers and a few storms have developed across the Treasure Coast and Okeechobee County. This activity is forecast to diminish by around 14Z, though brief periods of MVFR conditions will be possible at VRB and FPR through this time. Then, additional showers and storms are forecast to develop along the sea breeze, mainly from around MLB southward. These storms are expected to drift inland into the late afternoon and evening, though generally remain south of ISM and MCO. Light southerly winds will back east/southeasterly behind the sea breeze, remaining around 10 kts or less. && .FIRE WEATHER... Issued at 140 AM EDT Mon Jun 2 2025 Daily chances for lightning storms persist through the week, highest late today over the Treasure Coast and again by Wednesday for all areas. RH values remain above critical thresholds but approach 35- 40% over northern Lake and Volusia counties this afternoon. Moisture increases over all areas for the remainder of the week. && .PRELIMINARY POINT TEMPS/POPS... DAB 89 71 85 72 / 20 20 50 40 MCO 89 71 87 72 / 50 40 60 40 MLB 88 71 85 73 / 60 60 70 60 VRB 89 69 84 72 / 80 70 80 60 LEE 90 71 88 72 / 30 20 60 30 SFB 91 71 88 72 / 30 30 60 40 ORL 90 71 88 73 / 40 40 60 40 FPR 87 68 83 70 / 80 70 80 60 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ DISCUSSION...Heil AVIATION...Leahy