AFDMLB Area Forecast Discussion National Weather Service Melbourne FL 346 AM EST Thu Nov 21 2024 ...New KEY MESSAGES, DISCUSSION, MARINE, FIRE WEATHER... .KEY MESSAGES... Issued at 345 AM EST Thu Nov 21 2024 - A strong, southward-flowing longshore current is expected at area beaches, along with a moderate risk of rip currents - Significantly cooler, drier air arrives today and lasts into the weekend - Hazardous boating conditions over the local Atlantic waters through Friday, and sensitive fire weather conditions continue into the weekend && .DISCUSSION... Issued at 345 AM EST Thu Nov 21 2024 Today-Tonight...The pressure gradient is strengthening early this morning in the wake of a passing cold front. In response, northwest winds will gradually increase through the morning and into the afternoon. Significantly drier air is also on our doorstep, with GOES-derived PW already indicating PW less than 0.50" pushing into northeast Florida. Temperatures range from the mid 60s north of I-4 to the low 70s along the Treasure Coast. These values will fall quicker into the 50s and 60s through sunrise, while a gradual rebound into the upper 60s to mid 70s is forecast by the afternoon. Winds will be gusty at times, reaching 20-25 mph. In addition to gusty winds at the coast, a strong, southward- flowing longshore current is forecast to develop at area beaches today. Currents like these can quickly push swimmers into deeper water, making them more susceptible to getting caught in a rip current. Remember to always swim within sight of a lifeguard! Conditions remain breezy at the coast tonight as northwest flow ushers in even cooler air behind a reinforcing cold front. Low temperatures into Friday morning will dip into the mid to upper 40s for most, while coastal locations stay in the low 50s. A 20-30 percent chance for sub-40 degree temperatures exists along and north of I-4, according to the latest 00z HREF probabilities. This Weekend...Drier and cooler than normal conditions will last into the weekend. Friday is another breezy to gusty day with northwest winds 10-15 mph, peaking around 25 mph at times (especially at the coast). Despite plenty of sunshine, daytime highs will struggle to reach the mid and upper 60s Friday and Saturday but return to near normal (mid 70s) on Sunday as high pressure builds over Florida. The coldest morning of the next several, Saturday, will also combine with a light NW breeze to produce wind chills in the upper 30s over a large portion of ECFL. Note that temperatures could dip below 40 degrees briefly across northern Lake and Volusia counties Saturday morning. Monday-Wednesday...A warming trend resumes early next week as zonal mid level flow builds over the central and eastern CONUS. Dry weather continues as moisture fields are slow to recover until later in the week. Light onshore becomes established as daytime highs push into the upper 70s and low 80s. Morning lows Monday will still be in the mid to upper 40s north of I-4, rebounding into the 50s and low 60s areawide Tuesday and Wednesday morning. Model output diverges regarding the synoptic pattern over the CONUS Tuesday into Wednesday, which has downstream implications regarding what sensible weather we experience from Thanksgiving Day onward. Right now, we can anticipate near to slightly above normal temperatures for the holiday, along with mostly dry conditions. && .MARINE... Issued at 345 AM EST Thu Nov 21 2024 Today-Tonight...Quickly deteriorating and hazardous boating conditions are forecast through the day as northwesterly winds freshen and build seas. Early this morning, Buoy 41009 was reporting NW winds around 17 kt, gusting 20 to 25 kt. Farther north, Buoy 41117 indicated quickly increasing seas around 6 ft. This northerly wind surge will bring seas up to 4-7 ft nearshore and 8-9 ft offshore later this morning. NW winds 15-20 kt will pick up again after midnight, reaching 25 kt with gusts to 30 kt. A Small Craft Advisory is in effect for all legs of the adjacent central Florida Atlantic waters (out to 60 nautical miles). Friday-Monday...Hazardous boating is forecast to last through much of Friday, with gradual improvement Friday night into Saturday as winds and seas slowly decrease. 10-14 kt NW flow is anticipated on Saturday, falling below 10 kt for Sunday and Monday. Seas Friday around 5-8 ft in the Gulf Stream fall below 7 ft Saturday morning, decreasing further to 2-3 ft by Sunday. Favorable boating looks to persist through the middle of next week as high pressure becomes centered over the FL Peninsula and local waters. && .AVIATION... (06Z TAFs) Issued at 100 AM EST Thu Nov 21 2024 The cold front continues southward, with brief MVFR CIGs (BKN015) being observed along it. Have included TEMPO groups for MLB and the Treasure Coast to account for this. Behind the front, winds veering northwesterly and increasing, with gusts to around 20kts area-wide by daybreak. Skies will clear, as dry air moves into the area. However, winds will remain elevated, with gusts to around 25kts through the day. && .FIRE WEATHER... Issued at 345 AM EST Thu Nov 21 2024 Much drier air and breezy northwest winds will combine to produce sensitive fire weather conditions from today through the weekend. Relative humidity of 40 percent or lower is forecast each afternoon before moisture very slowly recovers by the middle part of next week. The most fire sensitive day appears to be Friday before wind speeds decrease this weekend. && .PRELIMINARY POINT TEMPS/POPS... DAB 68 45 66 43 / 0 0 0 0 MCO 67 48 67 45 / 0 0 0 0 MLB 70 48 68 45 / 0 0 0 0 VRB 73 47 70 46 / 0 0 0 0 LEE 68 46 67 43 / 0 0 0 0 SFB 69 46 67 43 / 0 0 0 0 ORL 69 48 68 45 / 0 0 0 0 FPR 74 47 70 45 / 0 0 0 0 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...Small Craft Advisory until 11 PM EST Friday for AMZ550. Small Craft Advisory until 4 PM EST Friday for AMZ552-555. Small Craft Advisory until 4 AM EST Saturday for AMZ570-572-575. && $$