Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
946 FXUS62 KMFL 201703 AFDMFL Area Forecast Discussion National Weather Service Miami FL 103 PM EDT Fri Sep 20 2024 ...New SHORT TERM, AVIATION, MARINE, BEACHES... .SHORT TERM... (Rest of today through Saturday) Issued at 1233 PM EDT Fri Sep 20 2024 With the previously stalled frontal boundary finally pushing south of our area this morning, South Florida should enjoy generally drier conditions for the rest of today and tomorrow! ACARS data at MIA captured the northerly wind shift earlier this morning, along with the drier mid-level air mass and PWATs trending down (down to 1.34 inches as of 12:30PM, near the 10th percentile for this time of year!). Nevertheless, there could still be some isolated showers and storms that develop later this afternoon along sea breeze boundaries, mainly south of Alligator Alley. Some of these showers and storms could be capable of producing heavy rain, with general accumulations of 1-2 inches, and localized amounts up to 2-4 inches possible as some moisture still lingers near the lower levels. This could result in localized flooding, especially if these heavy rain producers sit over areas with already saturated soils. Ensembles and ECMWF insist in pushing the aforementioned mid-lvl trough further south and through SoFlo on Saturday. In response, deeper ENE flow establishes, although still remaining weak (generally 3-8kt). This will be reinforced by broad high pressure developing over much of the SE CONUS, which will also usher drier air into the mid levels across the state. Nevertheless, hydro models keep at least chances for afternoon scattered showers and isolated thunderstorms, with POPs in the 40-50 percent. Temperatures and heat indices are expected to remain above seasonal climo, but stubborn cloudiness and possible rain activity should help in avoiding advisory criteria through the period. && .LONG TERM... (Saturday night through Thursday) Issued at 309 AM EDT Fri Sep 20 2024 As we wrap up the weekend and move into the new week, an expansive mid-level ridge will stretch across the Gulf of Mexico and into southeastern CONUS as the lingering trough drifts into the Atlantic. With this ridging, dry mid-level air will advect into the region with warm temperatures aloft. Although the mid-level drying is quite evident, with PWATs dipping down into the 1.4-1.7" range over portions of the area, there will be enough moisture remaining in the lower level with the assistance of a stationary surface boundary just to the south of the Keys keeping a sufficient supply of moisture in the southern half of the Peninsula. This will support daily scattered showers and isolated thunderstorms across the region. With the persistent easterly flow regime, the highest chance for rain will be over the western portions of South Florida. The relatively stable airmass will limit the deep convection most likely to the far southern third of the FL Peninsula. Looking further into the extended forecast, confidence is still minimal, as uncertainty increases if a portion of the Central American Gyre may consolidate into a more defined area of surface low pressure over the northwestern Caribbean or southern GOMEX (if forms at all). With the expansive forecast lead times, we will continue to monitor the tropics as the limited model guidance is indecisive and jumbled at the time being. In the upcoming days and as confidence grows, we will be watching the potential for the low`s development and the Gulf of Mexico`s future closely. The latest National Hurricane Center 2AM outlook has a 40% chance of tropical formation in the next 7 days. Temperatures will be near/just above seasonal normals with high temperatures in the upper 80s to low 90 and lows in the 70s. While the heat indices will likely reach the triple digits, the drier air will likely provide a relief from heat advisories due to dew points dropping into the low to mid 70s. && .AVIATION... (18Z TAFS) Issued at 1233 PM EDT Fri Sep 20 2024 VFR conditions should prevail through the period. Light northerly/northeasterly winds should persist. ISO SHRA/TSRA is once again expected to develop later this afternoon, but coverage is forecast to remain inland of the sites, so no inclusion of TEMPOS or PROB30s at this time. Conditions should improve shortly after sunset. && .MARINE... Issued at 1233 PM EDT Fri Sep 20 2024 Generally light winds continue today with a decaying frontal boundary moving across the area. Showers and thunderstorms will begin decreasing today as drier air slowly filters from the north behind the front. But there will be enough leftover moisture for isolated thunderstorms to develop in the afternoon hours, then the decreasing trend continues into the weekend. Brief periods of rough seas and gusty winds may accompany any thunderstorm that forms. && .BEACHES... Issued at 1233 PM EDT Fri Sep 20 2024 Minor to moderate coastal flooding continues during periods of high tide through the short period. These elevated tides will continue to affect all coastal areas of South Florida through late this morning, for which a coastal flood advisory remains in effect. Conditions should begin to improve on Sunday as northerly swell and the tidal influence decreases, but we could still see some minor coastal flooding during high tide. Additionally, a moderate risk of rip currents continues for the Palm Beaches during the next couple of days. NAPLES HIGH TIDE TIMES...2:57PM this afternoon, 2:15AM tomorrow LAKE WORTH HIGH TIDE TIMES...10:39 PM tonight, 11:18AM tomorrow && .PRELIMINARY POINT TEMPS/POPS... Miami 76 90 76 90 / 20 30 20 30 West Kendall 74 91 74 92 / 20 30 20 30 Opa-Locka 75 91 76 92 / 20 30 20 30 Homestead 75 90 76 90 / 20 30 30 30 Fort Lauderdale 76 88 76 89 / 10 30 20 30 N Ft Lauderdale 76 90 76 90 / 10 30 20 30 Pembroke Pines 76 92 76 92 / 20 30 20 30 West Palm Beach 76 90 76 90 / 10 30 20 20 Boca Raton 76 91 76 91 / 10 30 20 20 Naples 75 91 76 92 / 20 30 10 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 5 PM EDT Saturday for FLZ069-075- 168-172>174. AM...None. GM...None. && $$ SHORT TERM...ATV LONG TERM....JS AVIATION...ATV