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Show Area Forecast Discussion - Key West, FL (Florida Keys) Selection: |
| #1184060 (Received by flhurricane at: 8:03 PM 11.Jun.2024) AFDKEY Area Forecast Discussion National Weather Service Key West FL 357 PM EDT Tue Jun 11 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 355 PM EDT Tue Jun 11 2024 The weather has remained active this afternoon with most of the activity still pinned across the northern waters and south Florida mainland. That being said, there were some thundery squalls that raced off of Cuba and moved northward across the Lower Keys. One such squall produced a 40 knot (46 mph) wind gust at the Sand Key C-MAN station. Here at our office on White St, we saw a max wind gust of 32 knots (37 mph) from the same squall. Although cloud cover has kept temperatures in the mid 80s, a moisture-rich southerly flow is pumping in dew points into the upper 70s to near 80 at times. Current radar shows more convection is racing north from Cuba and at the same time, activity across the extreme southeast Gulf of Mexico is inching eastward towards the Dry Tortugas. A ridge axis stretches from the Yucatan Peninsula eastward across portions of the Great Antilles this afternoon but will gradually shift south overnight through Thursday. As it does, moisture rounding this ridge will become better aligned with the Florida Keys. As we have seen today, there is very little stopping precipitation from developing. The only limiting factor is organized lift which has been favoring areas to our north today. As mentioned the best moisture which lies to our north, will settle southward across the Keys through Thursday. This combined with a persistent trough to our west will keep rain chances high through the end of the week. By Friday, ridging will consolidate across the western Caribbean and begin lifting northward. This will eventually dislodge the tropical plume from our area, however, it will take until this weekend for rain chances to drop appreciably. No air mass changes expected and dew points will hold in the upper 70s to near 80 degrees at times, resulting in humid conditions, especially for this weekend. && .MARINE... Issued at 355 PM EDT Tue Jun 11 2024 A Small Craft Advisory is in effect for the western waters due to fresh southerly breezes. Thundery squalls continue to race north from Cuba and across our waters. The main activity lies across the outer Gulf waters but is showing signs of shifting south and east. The pattern this week will feature weak high pressure over the western North Atlantic and a frontal boundary stalled over northern Florida. Although, the main weather maker will be a large cyclonic gyre centered over Central America. As such, moderate to fresh breezes and an extended period of unsettled weather featuring thundery squalls will persist tonight through Friday night. Rain and thunder chances will decrease gradually starting Saturday. && .AVIATION... (18Z TAFS) Issued at 355 PM EDT Tue Jun 11 2024 Throughout the TAF period, shower and thunderstorm activity will continue to intermittently impact either terminal causing IFR conditions. For the time being VCTS and VCSH are included to represent nearby activity but TEMPOs will be included for direct impacts when necessary. Near surface winds will be southerly at 10 to 15 knots with gusts between 20 and 25 knots, but gusts in passing showers could near 35 knots. && .PRELIMINARY POINT TEMPS/POPS... Key West 80 88 80 87 / 80 70 60 70 Marathon 79 88 79 87 / 80 70 70 70 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Flood Watch through Wednesday evening for FLZ076>078. GM...Small Craft Advisory for GMZ033>035-044-054-055-074-075. && $$ |
| #1184026 (Received by flhurricane at: 2:30 PM 11.Jun.2024) AFDKEY Area Forecast Discussion National Weather Service Key West FL 1025 AM EDT Tue Jun 11 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 1025 AM EDT Tue Jun 11 2024 A cloudy and somewhat wet start to the day across the Florida Keys. Deep tropical moisture is pumping northward from the western Caribbean thanks to a combination of a low level ridge parked to our east and an approaching upper level trough from the west. Most of the current activity is located across the waters north of the island chain with additional convection racing up from the western Caribbean and Cuba. Cloud cover is keeping temperatures in the lower to mid 80s but the moisture-rich southerly flow has allowed for dew points to climb into the upper 70s to near 80. The combination of which is still producing heat index values in the mid to upper 90s this hour. Only minor changes made to the going forecast for the rest of today. A surge occurred early this morning and is still ongoing with the strongest winds across our western waters. Therefore, nudged winds slightly to account for this surge. Otherwise, with the deep tropical moisture in place and instability readily available it is just a matter of time until rain overspreads across the region. As such, will leave the likely PoPs in place. && .MARINE... Issued at 1025 AM EDT Tue Jun 11 2024 A Small Craft Advisory is in effect for the outer Gulf waters. Across the remaining waters with the exception of the Florida Bay, Small Craft Exercise Caution headlines are active. The pattern this week will feature weak high pressure over the western North Atlantic and a frontal boundary stalled over northern Florida. Although, the main weather maker will be a large cyclonic gyre centered over Central America. As such, moderate to fresh breezes and an extended period of unsettled weather featuring thundery squalls will persist today through Friday night. Rain and thunder chances will decrease gradually starting Saturday. && .AVIATION... (12Z TAFS) Issued at 1025 AM EDT Tue Jun 11 2024 VFR conditions will prevail at EYW and MTH for the next few hours. Thereafter, shower and thunderstorm activity is expected to pick up and move through the area in a northward motion causing potential IFR conditions. For the time being, VCSH and VCTS are included but as timing becomes more nailed down for exact airport impacts, TEMPOS will be included. Near surface winds will be southerly becoming more south to southwest at 10 to 15 knots with gusts between 20 and 25 knots, but gusts in passing showers could near 35 knots. && .CLIMATE... In 1999, the daily record rainfall of 2.50" was recorded. Local climate report says the rain fell in less than three hours, and the associated thunderstorms produced wind gusts estimated 50-60 mph and minor damage on Stock Island. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Flood Watch through Wednesday evening for FLZ076>078. GM...Small Craft Advisory for GMZ033-034. && $$ |
| #1184005 (Received by flhurricane at: 9:45 AM 11.Jun.2024) AFDKEY Area Forecast Discussion National Weather Service Key West FL 542 AM EDT Tue Jun 11 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 542 AM EDT Tue Jun 11 2024 Convective activity has ramped up across the Florida Keys forecast area overnight. KBYX is detecting scattered light to moderate rainfall, with a few embedded heavier showers. Earlier, a strong thunderstorm moved across Carysfort Reef Light and produced a wind gusts of 46 mph. Winds have picked up a few knots higher than expected in the western coastal waters and across the Lower Keys, and the Sand Key C-MAN station is reporting gusts of 22 knots. The upcoming week is proving to be quite a tricky forecast, as evidenced by the lack of measurable rainfall in most island communities overnight. Last night`s sounding sampled all of the necessary parameters (i.e. high CAPE, virtually no inhibition, and well above normal moisture), but rainfall has been scarce along the island chain. This has likely been due to the diffluence across our area thanks to a low-level ridge axis extending across the Bahamas and South Florida. The diffluence at the surface can still be seen, with a southeast to south wind direction at Sand Key and a southwest wind direction at Carysfort. This ridging will be one of the factors causing the above normal uncertainty in the forecast over the next few days. Despite any uncertainties, the knowns in the forecast are pointing to a wet few days of weather for the Florida Keys. The generally synoptic set is a broad trough (Central American Gyre) pushing deep tropical moisture into the region for the remainder of the week. A stalled front, currently lingering along the Gulf Coast, will remain stalled with maybe a little southward movement through the week. This front will act to keep moisture trapped across the Gulf for a prolonged period. The Weather Prediction Center has placed the entirety of South Florida and the Florida Keys in a Slight Risk (level 2 of 4) of excessive rainfall today through Friday due to the extended stay of this tropical moisture plume. Now let`s talk uncertainties...As previously mentioned, winds have already jumped to above what was expected. Guidance suggests that these winds should start to decrease by this afternoon, so have issued a Small Craft Advisory for the western waters through at least later this morning. Just how far these stronger winds will extend eastward and their exact magnitude for the remainder of the day is a little fuzzy, and amendments to the wind forecast may be necessary if anything drastically changes. In terms of rainfall, model guidance is suggesting that we will become weakly confluent later this morning. This confluence combined with a forecasted 25-30 knot steering flow and well above normal PW should, in theory, lead to widespread rainfall. The best confluence will be to our north, so we could see a rather dramatic rainfall gradient across our area. This environment will generally remain in place through the end of the week, so have kept rain chances at likely to categorical (60-80%) through Friday. Have also decided to issue a Flood Watch for the entire Florida Keys with the expected rainfall. With the uncertainties involving stark gradient that will likely set up somewhere in our area, have only issued the Flood Watch through Wednesday night at this time. Depending on the evolution of the environment over the next 36 hours, this watch may need to be extended through the remainder of the week. By the start of the weekend, ridging will begin to build back in and shove the best moisture to our west. Rain and thunder chances will finally begin to diminish beginning on Saturday night, but will still remain slightly above normal through the extended forecast. && .MARINE... Issued at 542 AM EDT Tue Jun 11 2024 A Small Craft Advisory was issued for the western coastal waters including the western Straits, western Hawk, and Gulf waters including the Dry Tortugas. Elsewhere besides the Florida Bay, small craft should exercise caution until winds decrease. From synopsis, the pattern this week will feature weak high pressure over the western North Atlantic and a frontal boundary stalled over northern Florida. Although, the main weather maker will be a large cyclonic gyre centered over Central America. As such, moderate to fresh breezes and an extended period of unsettled weather featuring thundery squalls will persist today through Friday night. Rain and thunder chances will decrease gradually starting Saturday. && .AVIATION... (06Z TAFS) Issued at 542 AM EDT Tue Jun 11 2024 Showers and thunderstorms began developing in waters surrounding the Florida Keys before 7Z, but active weather transitions between VFR and potentially IFR conditions will dominate the TAF period. Current observations and hi-res model guidance suggests VCSH conditions at the terminals will begin before sunrise. Showers are expected to approach EYW and MTH in waves as a mixture of VCSH and VCTS throughout the TAF period. Expect rapid deterioration in flight conditions when heavy showers and lower CIGs move ashore. The timing the approach of individual thunderstorms is extremely uncertain, resulting in the absence of TEMPOs from the TAFs. Prevailing near- surface winds will remain southerly to later southwesterly within a range of 10 to 15 knots and gusts between 20 and 25 knots, but gusts may approach 35 knots near showers. && .CLIMATE... On this day in 1999 in Keys weather history, the daily record rainfall of 2.50" was measured at Key West. Local climate report says the rain fell in less than three hours, and the associated thunderstorms produced wind gusts of 50-60 mph that minor damage on Stock Island. Rainfall records for Key West date back to 1871. && .PRELIMINARY POINT TEMPS/POPS... Key West 88 79 87 80 / 80 80 80 60 Marathon 88 80 87 80 / 80 80 80 60 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Flood Watch through Wednesday evening for FLZ076>078. GM...Small Craft Advisory for GMZ033>035-044-054-055-074-075. && $$ |
| #1183970 (Received by flhurricane at: 3:06 AM 11.Jun.2024) AFDKEY Area Forecast Discussion National Weather Service Key West FL 1050 PM EDT Mon Jun 10 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 1020 PM EDT Mon Jun 10 2024 The current radar depiction is in stark contrast to the vertical profile sampled by the 00Z KKEY RAOB. In fact, the RAOB was launched during the arrival of a relic outflow boundary, and probably underestimates the ML instability. The profile features deep southerlies underneath westerlies. PW was ~2.3" and there was plenty of CAPE and minimal inhibition. The CAPE profile is thick enough as the westerlies develop in the mid levels to not suggest a shear problem. Although the late afternoon radar loops featured arcing lines of showers and thunderstorms, the scope is nearly echo free this hour. Regional surface observations and CIMSS low-level vorticity analyses place a weak cyclonic node over the southeastern Gulf a couple hundred miles north of the Yucatan, and we can see the swirl on satellite. Meanwhile, South Florida is within the low- level ridge corroborated by the anticyclonic shower and storm motion and the southwesterly SFC winds along the Southwest Florida Coast. This places the Keys in rather strong low-level diffluence this evening, which has been destructive to moisture convergence. As South Florida cools, the micro ridge should bulge southwest and place the Keys back in confluent, albeit anticyclonic flow. The advertised 60% rain/thunder chances appear appropriate, well above normal and below the MOS consensus. The wind forecast remains a challenge. The gradient will be controlled by occasional convective episodes, so we went with a muted mean near 15 knots at the Reef by Daybreak. && .MARINE... Issued at 1020 PM EDT Mon Jun 10 2024 The pattern this week will feature weak high pressure over the western North Atlantic and a frontal boundary stalled over northern Florida. Although, the main weather maker will be a large cyclonic gyre centered over Central America. As such, moderate to fresh breezes and an extended period of unsettled weather will persist tonight through Friday night. Rain and thunder chances will decrease gradually starting Saturday. && .AVIATION... (00Z TAFS) Issued at 1020 PM EDT Mon Jun 10 2024 Diffluent low-level flow resulting in VFR at both terminals this evening. However, low-level flow will become more confluent overnight, coupled with an unstable, moist, and weakly inhibited profile sampled by the 00Z KKEY RAOB. By late morning Tuesday, or the early afternoon, a potent convergence zone will develop just to the north of the Keys, and VCTS is advertised at both terminals. && .PRELIMINARY POINT TEMPS/POPS... Key West 80 87 80 88 / 70 80 70 70 Marathon 81 87 80 88 / 60 70 70 70 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ |
