Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
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178 FXUS62 KMFL 171910 AFDMFL Area Forecast Discussion National Weather Service Miami FL 310 PM EDT Tue Sep 17 2024 ...New LONG TERM... .SHORT TERM... (Rest of today through Wednesday) Issued at 203 PM EDT Tue Sep 17 2024 A deep-layered area of low pressure continues to sit over the southeastern United States with an associated frontal boundary sagging south across the peninsula of Florida. This setup will remain over the region through mid-week which will lead to a more unsettled pattern but mitigate the heat risk compared to previous days. Thunderstorms on both days could see some enhanced support from an upper level jet and some periods with a healthy low level jet. Ample moisture will allow for convective coverage and PoPs to remain above climatological norms for this time of year with more activity than just a normal sea breeze thunderstorm day. Boundary collisions and sea breeze interactions could provide some lower level enhancement that could lead to strong to isolated severe thunderstorms. Strong to locally damaging winds and localized flooding from excessive rainfall continue to be the main concerns. Temperatures will be warm but heat index values will not be as hot as in recent days. The extra cloud cover could help limit the fast-pace of diurnal heating in the mornings and reinforced cold pools in the wake of convection could provide some brief periods of relatively cooler temperatures. && .LONG TERM... (Wednesday night through next Monday) Issued at 309 PM EDT Tue Sep 17 2024 Towards the end of the week and into the early weekend, the upper troughing will continue to dig southward into the NE Gulf of Mexico and South Florida, maintaining west-northwesterly flow over the region aloft. Meanwhile a slog of deep tropical moisture remains in place over the region as a diffuse stationary frontal boundary meanders through this period. The presence of cooler upper level temperatures (-6 to -7C @ 500 mb) and a pocket of divergence aloft may act to enhance convective coverage and intensity at times, though most convective will be driven by localized convergence maxima owing to mesoscale processes. Expect bouts of periodic heavy rainfall to continue, particularly in the afternoon when instability and low-level convergence is maximized. By Sunday and into early next week, a dominant/expansive ridge of high pressure will emanate from the TX/Mexico region and increase geopotential heights across South Florida. This may be commensurate with a wedge of drier air advecting towards the region through this same period (simultaneously), though there exists uncertainty regarding the southward extent of this drier airmass. For now, it appears that strong upper ridging coupled with a lack of moisture should allow for rainfall totals that are below climatological norms through this period. Temperatures through this period will hover around seasonal norms through this period. Afternoon high temperatures should reach the upper 80s to low 90, while dewpoints reach the mid to upper 70s through the early part of the weekend. Heat Advisories could be necessary through this period, though this will be contingent on the rainfall influence for a given day. Towards the end of the weekend and into early next week, dewpoints may drop a few degrees, although less cloud coverage and rainfall could allow for more oppressive temperatures through this period. && .AVIATION... (18Z TAFS) Issued at 203 PM EDT Tue Sep 17 2024 Once the sea breezes develop and slowly advance inland, the highest risk for sub-VFR will be this afternoon into the early evening. Short-fused AMDs for IFR/LIFR may be necessary for directly impacted terminals. Light wind flow will prevail through much of the period turning onshore briefly with the sea breezes in the afternoon. Conditions should improve to VFR late evening into the overnight though some patchy inland fog/low stratus is possible. Shower and storm chances will increase on Wednesday morning. && .MARINE... Issued at 203 PM EDT Tue Sep 17 2024 Generally light winds will prevail through most of this week as a weak surface boundary remains just to the north of the area. Seas across the northern Atlantic waters will gradually lessen as northerly swell declines through mid-week. Scattered showers and thunderstorms will be possible each day through the period and could lead to locally higher winds and seas. && .BEACHES... Issued at 203 PM EDT Tue Sep 17 2024 Decreasing northerly swell will result in a high risk of rip currents for the Palm Beaches once again today with a moderate risk of rip currents elsewhere on the east coast of South Florida. There will also be the continued potential for minor to moderate coastal flooding around periods of high tide due to astronomically higher tides associated with this full moon through mid-week. High Tide Times: * Naples: 1256 PM Tuesday, 125 AM Wednesday, 146 PM Wednesday * Lake Worth: 814 PM Tuesday, 838 AM Wednesday, 901 PM Wednesday * Port Everglades: 831 PM Tuesday, 858 AM Wednesday, 919 PM Wednesday * Virginia Key: 918 PM Tuesday, 945 AM Wednesday, 1004 pm Wednesday && .PRELIMINARY POINT TEMPS/POPS... Miami 77 90 77 89 / 40 70 40 70 West Kendall 75 90 74 90 / 40 70 40 70 Opa-Locka 76 90 76 91 / 40 70 40 70 Homestead 76 90 76 89 / 40 70 40 70 Fort Lauderdale 77 89 76 89 / 40 60 40 70 N Ft Lauderdale 77 90 77 90 / 40 60 40 70 Pembroke Pines 77 92 77 92 / 40 70 40 70 West Palm Beach 76 91 76 91 / 40 60 40 60 Boca Raton 76 91 76 91 / 40 60 40 60 Naples 77 91 77 91 / 30 50 30 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 2 PM EDT Thursday for FLZ069-075- 168-172>174. High Rip Current Risk through Wednesday evening for FLZ168. AM...None. GM...None. && $$ SHORT TERM...RAG LONG TERM....SRB AVIATION...RAG