Area Forecast Discussion
Issued by NWS Melbourne, FL
Issued by NWS Melbourne, FL
853 FXUS62 KMLB 111956 AFDMLB Area Forecast Discussion National Weather Service Melbourne FL 356 PM EDT Sat May 11 2024 ...New DISCUSSION, AVIATION, MARINE, FIRE WEATHER... .DISCUSSION... Issued at 207 PM EDT Sat May 11 2024 ...Increasing potential for much-needed rain next week, but this may be accompanied with a threat for strong to severe storms... Current-Tonight... The east coast sea breeze has formed and is currently pushing inland this afternoon. Mostly quiet on the KMLB radar this afternoon, with a few light returns north of the local area. Local observations shows temperatures as of 3PM are in the upper 80s to low 90s with a few low and high level clouds streaming overhead. Surface analysis shows the cold front is currently draped across the Treasure Coast and Okeechobee counties. North to northeast winds have developed behind the cold front with speeds increasing to 8-13 mph as the sea breeze pushes through. Increasing moisture across the Treasure Coast this afternoon (PW values ranging from 1.6-1.9") will support isolated showers (PoP percent) to continue across the treasure Coast and Okeechobee counties into this afternoon. Instability will also increase today across the south, with MUCAPE around 2200 + J/kg across the Treasure Coast. This will support isolated lightning storm chances through the afternoon across that area as well. Some storms may be strong. Storms that develop today will be capable of producing occasional to frequent lightning strikes, gusty winds of 40-50 mph, and locally heavy rainfall. Otherwise, expect mostly dry conditions today, with partly to mostly sunny skies. Hot conditions will remain in place despite the frontal boundary. Afternoon highs will range from the mid 80s to low 90s along the coast where a sea breeze will form and shift inland, and low to mid 90s over the interior. Any lingering convection across the Treasure coast will gradually dissipate this evening, as the front continues to move southward across South Florida and drier air filters across the area. Overnight lows will be average to slightly above average with lows in the 60s across most locations, with mostly clear skies. Sunday... Upper level trough across the Northeast will slowly shift eastward as zonal flow persists across the south with shortwave energy traversing across the Florida peninsula. At the surface, high pressure will build across the region as it slowly shift eastward. Locally, expect north to northeast winds to persist with speeds around 5-8 mph. The east coast sea breeze is forecast to develop and push inland, with speeds increasing to 10-12 mph behind the sea breeze. Drier air remains in place, allowing for most locations to remain dry Sunday. However, isolated showers (PoP 20 percent) and isolated lightning storms will be possible in the afternoon, mainly across the south. Forecast soundings show PW values ranging from 1.3- 1.5" in the afternoon. Guidance is indicating that mid to higher level clouds will be streaming across the local area into the afternoon. Hot conditions will remain, with above average temperatures forecast under partly to mostly sunny skies. Afternoon highs will be in the mid to upper 80s along the coast, and upper 80s to low 90s across the interior. Sun Night-Mon Night...Weak, flat-ridging in the mid-levels over the GoMex moves across the FL peninsula during this time with mainly zonal flow. Subtle shortwave impulses will traverse the peninsula (esp north) during this time. At the surface, weak high pressure over the western Atlc will promote onshore flow while winds veer to SE, then SSE/S by the end of the period. PWATs steadily climb thru the end of the period. A sea breeze collision is likely well into the interior late on Mon. Conditions mostly dry over land Sun night- Mon early afternoon. Precip chances increase into late afternoon- evening on Mon. Currently we advertise 30-40pct along the coast and 50pct interior late Mon/Mon evening. Very warm nights ahead with mins in the U60s to L70s and cannot rule out a couple of M70s for lows. Highs on Mon in the M80s at the immediate coast and U80s to L90s into the interior. Tue-Wed...A mid-level low over the Ozarks translates eastward across the Tennessee/Ohio valleys with shortwave energy accompanying it east/south carrying thru the north FL peninsula. PWATs across ECFL will vary from 1.65-2.00 inches during this time. The WCSB will be dominant on both of these days. The ECSB will develop on Tue, then perhaps only along the Space/Treasure coasts on Wed, with inland propagation stymied (both days) due to the stronger/deeper offshore flow. As such, afternoon/evening showers/storms should favor the eastern peninsula with storm motion SWRLY 25-30 mph. A few strong to marginally severe storms will be possible each day (late aftn/evening) - esp closer towards the coast due to stronger boundary collisions. Marine interests will need to keep an eye to the sky across the Intracoastals for fast approaching/developing storms. Primary storm threats in play include frequent cloud-to- ground/water strikes, gusty winds 40-50 mph, one or two storms to 60 mph, small hail up to quarter-size, torrential downpours, and a brief tornado cannot be ruled out. Atmospheric mixing during heating each afternoon will likely promote breezy/gusty conditions in the afternoon. Due to dry vegetation, cannot rule out lightning-induced brushfires and gusty winds could promote fairly quick fire spread rates making containment difficult should this play out. Very warm each day with near 90F along the coast and L-M90s (few U90s) inland on Tue and U80s to L90s on Wed, except M-U90s across Okeechobee/interior Treasure Coast. Peak heat indices on Tue 100- 106F across much of the area and 100-107F from Melbourne southward on Wed. Lows remain consistent in the U60s to L70s with a few M70s sprinkled in. Thu-Sat...Ridging begins to amplify from the southern GoMex northward resulting in increasing H5 heights across the FL peninsula and warming mid-level temps. At the surface, generally a weak pressure pattern will persist thru the period. We will see a daily sea breeze regime with ISOLD-SCT afternoon/evening lightning storms. Continued very warm with U80s/90F immediate coast and L-M90s inland; perhaps a few U90s Thu/Fri. Peak Heat Indices 98-105F across much of the coverage warning area. && .AVIATION... (18Z TAFs) Issued at 207 PM EDT Sat May 11 2024 VFR conditions through the TAF period. Isolated showers and lightning storms will remain possible along the Treasure Coast and Okeechobee counties through the Afternoon. Have included VCSH at SUA for this afternoon until 20Z. Otherwise, dry. W/NW winds up to 10- 12KT today will veer N/NE this afternoon behind the sea breeze as it pushes inland. Winds will become light and variable overnight. Winds will become northeast and increase to around 5 KT by mid morning. && .MARINE... Issued at 207 PM EDT Sat May 11 2024 Current-Sunday... Favorable boating conditions continue. Cold front across the Treasure Coast waters this afternoon will shift south of the local area into this evening and will remain across South Florida through the period. High pressure will build in behind the front and continue through Sunday as it shifts slowly eastward. North to northeast winds 5-10 KT will veer eastward Sunday afternoon with the formation of the east coast sea breeze. Seas 2-4ft this afternoon will decrease to 2-3ft overnight and remain through Sunday. Isolated showers and lightning storms will be possible Sunday afternoon, mainly across the Treasure Coast. Sun Night-Thu...Weak high pressure over the western Atlc will provide for initial onshore flow into Mon evening, then winds become more southerly overnight/daybreak Tue with an offshore component by mid-week. Initial wind speeds 7-13 kts increase during the day on Mon to 12-18 kts and 15-20 kts Mon night-Tue evening; perhaps 18-22 kts Gulf Stream Tue aftn-evening. Winds remain elevated over the Gulf Stream and no significant improvement until Wed afternoon-Thu back to 10-15 kts on average. An unsettled pattern develops with disturbed weather and increasing shower/ISOLD-SCT lightning storm chances thru mid-week (offshore-moving Tue/Wed - couple strong to marginally svr late day-evening). Seas 2-4 ft Mon building to 3-5 ft on Tue, back to 2-4 ft Tue overnight, then AOB 3 ft again by Thu. && .FIRE WEATHER... Issued at 207 PM EDT Sat May 11 2024 Sunday... Fire sensitive weather conditions will continue as drier air remains in place behind the frontal passage. Min RH values will drop into the mid to upper 30s to low 40s across the interior, with low 30s across the far western interior. Northeast winds will be 5- 10 mph on Sunday with the east coast sea breeze forecast to develop and push inland, veering the winds easterly in the afternoon. Isolated showers and lightning storms will be possible Sunday afternoon, mainly across the Treasure Coast and Okeechobee counties. Otherwise, no mentionable rain chances. Mon-Thu...Moisture and shower/lightning storm chances increase thru the period, with Min RH values forecast to remain above critical values. Until we receive enough wetting rainfall areawide, there could be potential fire ignitions from cloud-to-ground lightning strikes with any storm given the overall dry conditions. Tue/Wed afternoon`s likely sustained (offshore) winds approaching 10-16 mph/12-18 mph, respectively with frequent higher afternoon gusts. Storms, esp Tue-Wed afternoons will contain gusty/erratic outflows. Very warm temperatures return with heat indices will increase well into the 90s and L100s - especially Tue thru the end of the week! && .PRELIMINARY POINT TEMPS/POPS... DAB 68 85 70 85 / 0 10 0 40 MCO 69 90 71 92 / 0 10 0 50 MLB 71 85 72 86 / 10 10 0 40 VRB 69 87 71 88 / 10 20 0 40 LEE 68 89 72 92 / 0 10 0 40 SFB 68 89 70 90 / 0 10 0 50 ORL 70 90 71 91 / 0 10 0 50 FPR 68 87 70 87 / 10 20 0 40 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ SHORT TERM...Watson LONG TERM...Sedlock AVIATION...Watson