Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
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064 FXUS62 KMFL 212323 AFDMFL Area Forecast Discussion National Weather Service Miami FL 723 PM EDT Fri Jun 21 2024 ...New AVIATION... .SHORT TERM... (Rest of today through Saturday) Issued at 1231 PM EDT Fri Jun 21 2024 As a tropical disturbance (Invest AL92) continues to move northwestward this afternoon towards the Florida/Georgia coastline, some drier air continues to wrap around the southern side of the low towards the Lake Okeechobee region as well as South Florida. This will help to limit the coverage of convection across the region for the rest of this afternoon and into this evening. However, there does remain enough lower level moisture to support some shower and thunderstorm development with the main focus of initiation being sea breeze boundaries. With the drier air pocket pushing into the mid levels, this will also act as a cap which will help to keep strong thunderstorm development rather limited this afternoon. As east to southeasterly wind flow remains in place, the highest chances of showers and thunderstorms will remain over the interior and west coast heading into the afternoon and evening hours. While most of the convection over land will diminsh as the evening progresses, the hi res models are showing increasing shower and thunderstorm development over the Atlantic waters overnight as the drier air pocket erodes and moisture increases. Low temperatures tonight will generally range from the lower to mid 70s across the Lake Okeechobee region to around 80 across the east coast metro areas. On Saturday, the tropical disturbance will have pushed inland across Northern Florida and Southeastern Georgia, however, the weakness in the mid level ridging will still remain in place across the region. This will allow for a light steering flow through the day as the surface flow remains east southeasterly. As moisture advection continues throughout the day and PWAT values range between 2.1 and 2.3 inches, the coverage of showers and thunderstorms will be higher compared to this afternoon. The main focus of convection will still be sea breeze driven, however, with the lighter steering flow in place, convection may linger closer to the east coast metro areas upon development before slowly pushing towards the interior and west. Some stronger thunderstorms cannot be ruled out mainly across the interior sections on Saturday afternoon and they could contain gusty winds and heavy downpours. High temperatures on Saturday will generally range from the upper 80s along the east coast to the lower 90s across Southwest Florida. && .LONG TERM... (Saturday night through next Thursday) Issued at 322 PM EDT Fri Jun 21 2024 A mid-level trough is forecasted to dip southward across the Great Lakes on Sunday, triggering the breakdown of the dominant mid-level ridging over the region. Consequently, the expansive surface ridging over the western Atlantic will weaken and retreat, gradually weakening the easterly surface flow. Despite this change, there will still be sufficient easterly flow to drive convection across the western half of South Florida. Combining large-scale ascent and low- level forcing from sea breeze boundaries will enhance rain chances late this weekend. On Monday, a notable shift in the weather pattern is expected as the surface flow is forecasted to change to a more southerly direction. This is due to the waning influence of the high-pressure ridge. The shift in the surface flow will concentrate convection primarily in inland areas, particularly around the lake and other inland locations, where boundary collisions will be more frequent. During this period, deeper tropical moisture (PWATs exceeding 2 inches) from the ongoing Central American Gyre (C.A.G.) will continue to move into South Florida, sustaining elevated rain chances each afternoon. It is important to note that the NBMs PoPs are too high, so a reduction has been implemented. As we progress into Tuesday, mid-level troughing will become established over the eastern United States, accompanied by a surface frontal boundary extending into the southeastern United States. In response, surface winds will veer southwesterly, altering the weather pattern. This southwesterly flow will promote the inland progression of the Gulf sea breeze while confining the Atlantic sea breeze to the East Coast. As a result, the highest concentration of convection is expected along the East Coast metro areas from Tuesday through Wednesday. With PWATs ranging between 1.8 and 2.2 inches throughout the week and light 500mb flow in place, localized flooding remains a concern, particularly in urban areas that experienced significant rainfall last week. Some uncertainty marks the extended forecast period. Numerical guidance suggests that drier air, possibly a burst of Saharan dust, could approach the region. Alternatively, other models indicate that tropical moisture from the Caribbean could move into the CWA, driven by mid-level troughing. Seasonal temperatures are expected to prevail throughout the forecast period with heat indices exceeding 100. && .AVIATION... (00Z TAFS) Issued at 720 PM EDT Fri Jun 21 2024 Increasing SHRA activity across the east coast terminals during the early morning hours with widespread SHRA/TSRA developing across South Florida tomorrow. Handled with VCSH/VCTS for now given low confidence on timing/spatial extent. However, TEMPOs and amendments may be needed tomorrow if SHRA/TSRA activity trends increase and if terminals are directly impacted. && .MARINE... Issued at 1231 PM EDT Fri Jun 21 2024 A gentle to moderate east to southeasterly wind flow will remain in place across most of the local waters into the upcoming weekend. These winds will gradually veer and become more southerly as the early portion of next week progresses. Seas across the Atlantic waters will remain at 2 to 4 feet through the first part of the weekend before subsiding and will remain at 2 feet or less through the second half of the weekend and into early next week. Seas across the Gulf waters will remain at 2 feet or less through the weekend and into early next week. Scattered to numerous showers and thunderstorms will be possible each day. Winds and waves could be locally higher in and around showers and storms. && .BEACHES... Issued at 1231 PM EDT Fri Jun 21 2024 A high risk of rip currents will continue for the Atlantic Coast Beaches through Saturday evening. The rip current risk could remain elevated through the rest of the weekend and into early next week as onshore flow remains in place. && .PRELIMINARY POINT TEMPS/POPS... Miami 80 90 79 89 / 30 60 30 70 West Kendall 78 91 77 90 / 30 60 30 70 Opa-Locka 80 91 78 91 / 30 60 30 70 Homestead 80 89 78 88 / 30 60 40 60 Fort Lauderdale 81 88 80 88 / 30 60 30 70 N Ft Lauderdale 81 89 80 88 / 30 60 30 70 Pembroke Pines 82 91 80 91 / 30 60 30 60 West Palm Beach 80 90 78 89 / 30 60 30 60 Boca Raton 80 90 79 89 / 30 60 30 60 Naples 77 92 77 90 / 40 70 40 70 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through Saturday evening for FLZ168-172- 173. AM...None. GM...None. && $$ SHORT TERM...CWC LONG TERM....Pine AVIATION...Hadi