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Show Area Forecast Discussion - Key West, FL (Florida Keys) Selection: |
| #1182704 (Received by flhurricane at: 7:12 PM 01.Jun.2024) AFDKEY Area Forecast Discussion National Weather Service Key West FL 300 PM EDT Sat Jun 1 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 300 PM EDT Sat Jun 1 2024 KBYX radar has remained quiet for much of the day. However, within the past hour, a shower has developed near Biscayne Bay south of Miami. This shower was moving to the southwest to west at 5 to 10 knots. GOES 16 Visible satellite imagery shows mostly fair weather cumulus throughout the Florida Keys with any stratocumulus confined to the Upper Keys closer to the shower. Temperatures along the Island Chain are in the upper 80s to near 90 degrees with the Big Pine Key RAWS coming in with 92 degrees. Dew points are in the lower 70s as the modified continental air mass remains over the area. Strong surface high pressure just off the North Carolina coastline is dominating the pattern across much of the Southeastern United States, including Florida. As a result, marine platforms are observing northeast to east winds of 15 to 20 knots with Island Chain communities observing 15 to 20 mph. .FORECAST... The aforementioned surface high pressure continues to drive farther southeast into the Atlantic over the next couple of days. As a result, expect fresh breezes to continue through this evening before gradually relaxing through the remainder of the weekend and into early next week. Regarding rain chances, mid and upper level troughing deepens slightly across the area with weak shortwaves/perturbations moving through the flow. The upper trough will be accompanied by a 70 knot jet streak placing the Keys in the left exit region of this jet for the next several time periods as it slowly traverses eastward through early next week. Therefore, expecting an uptick in convective activity beginning tonight across the Keys. Due to this, increased PoPs tonight to 40% from 30% and also increased Sunday through Monday from 40% to 50%. Model guidance is also showing instability on the rise for the next few forecast periods. We decided to keep tonight slight chances for thunder but decided to increase Sunday through Monday to chances of thunder. With the mid to upper level support and attendant jet streak, hi-res guidance is hinting at these showers and thunderstorms potentially having a fair bit of wind energy with them and therefore, some of the showers and thunderstorms could have strong gusty winds where they occur. Also, while we had cloud lines today, conditions become a bit more favorable for Sunday especially with the increasing moisture. After Monday, we lose the upper level trough with zonal flow commencing for Monday night through mid week, though, mid level troughing remains along with low level moisture. Therefore, based on this, chance PoPs were maintained. For late week into the first half of next weekend, model guidance is differing mainly on the timing of features in the upper levels. Model guidance seems to be honing in on a closed upper level low developing somewhere in the vicinity of northern to central Florida while it moves northeastward. With lingering moisture and mid to upper troughing remaining, chance PoP were maintained through this period. && .MARINE... Issued at 300 PM EDT Sat Jun 1 2024 Winds are expected to surge across much of the Keys late this afternoon continuing through 11 PM this evening before gradually subsiding. As a result, a Small Craft Advisory is back in effect for all the Florida Keys coastal waters until 11 PM EDT. From synopsis, high pressure just off the eastern North Carolina coastline will continue moving farther southeast into the western North Atlantic tonight. This will result in moderate to fresh northeast to east breezes. The aforementioned high sets up over the western North Atlantic for Sunday through the middle of next week while slowly weakening. This will result in gentle to moderate breezes peaking in the afternoon and evenings and lulling overnight into the morning hours. Breezes will further slacken towards late week as the high continues to loosen its grip. && .AVIATION... (18Z TAFS) Issued at 300 PM EDT Sat Jun 1 2024 Through 02/18Z, prevailing VFR conditions are expected at both EYW and MTH. Scattered rain showers with moderate to heavy precipitation may develop after 02/00Z and move within the vicinity of either MTH or EYW. An isolated thunderstorm is not out of the question. However, chances of sub-VFR conditions are too low for inclusion in the TAFs. Cell motions likely would be from 065/15KT. && .CLIMATE... On this day in day in Keys Weather History, the daily record low of 65F was measured at Marathon in 1955. This measurement tied for the coldest temperature ever recorded in the month of June. Temperature records at Marathon date back to 1951. && .PRELIMINARY POINT TEMPS/POPS... Key West 88 80 88 80 / 20 30 50 50 Marathon 87 80 88 80 / 20 40 50 50 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Small Craft Advisory until 11 PM EDT this evening for GMZ031>035- 042>044-052>055-072>075. && $$ |
| #1182675 (Received by flhurricane at: 2:45 PM 01.Jun.2024) AFDKEY Area Forecast Discussion National Weather Service Key West FL 1040 AM EDT Sat Jun 1 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 1034 AM EDT Sat Jun 1 2024 KBYX radar remains quiet this morning as GOES 16 Visible satellite imagery shows mostly fair weather cumulus clouds streaming from west to east across the Florida Keys. Temperatures along the Island Chain are in the mid to upper 80s with dew points in the lower 70s. When you step outside, there is definitely a noticeable feel to the air being drier than it was at this time yesterday as we we experience slightly modified continental air. Surface high pressure over eastern North Carolina is about to emerge out into the western North Atlantic which is the main driver for the sensible weather across the Keys today. This is resulting in marine platforms observing northeast to east winds of 15 to 20 knots with Island Chain communities observing near 15 mph. .SHORT TERM FORECAST... The 12z morning sounding showed a dry profile from the surface up to the top of the atmosphere. However, there is an inversion present around 900 mb with some moistening below this to 930 mb. Where there is slight moistening on the sounding pairs up nicely with what we are seeing on visible satellite imagery this morning with the cloud bases around 3200-4000 ft AGL. The wind profile is fairly unidirectional with winds mainly out of the east near 20 knots, perhaps with slight veering. CAPE is not that high with values around 400 J/kg which is lower than at this point yesterday when it was near 2000 J/kg. Therefore, more stable air has moved into the Keys when compared to this time yesterday. Also, the PWAT value measured is quite dry coming in at 1.27 inches which is below the 25th percentile for the date which is 1.37 inches. Based on the above, outside of perhaps some speed convergence, thinking it will remain fairly dry today across the Keys outside of perhaps a shower or two that tries to form along one of the cloud streamers. Therefore, no change expected to ongoing forecast. && .MARINE... Issued at 1034 AM EDT Sat Jun 1 2024 Small Craft Should Exercise (SCEC) remains headlined across all the Florida Keys coastal waters, except for the Straits of Florida where a Small Craft Advisory remains in effect. The Small Craft remains in effect for seas up to 7 feet in the Gulf Stream. From synopsis, high pressure over eastern North Carolina will continue moving southeastward emerging off the coast this afternoon. This high continues moving further into the western North Atlantic through the middle of next week. This will result in moderate to fresh northeast to east breezes through the weekend. Breezes are expected to slacken during early to mid next week as the aforementioned high weakens. && .AVIATION... (15Z TAFS) Issued at 1034 AM EDT Sat Jun 1 2024 Through 02/12Z, prevailing VFR conditions are expected at both EYW and MTH. A few rain showers with light to moderate precipitation may develop after 02/00Z and move within the vicinity of either MTH or EYW. Cell motion likely would be from 065/15KT. && .CLIMATE... On this day in day in Keys Weather History, the daily record low of 65F was measured at Marathon in 1955. This measurement tied for the coldest temperature ever recorded in the month of June. Temperature records at Marathon date back to 1951. && .PRELIMINARY POINT TEMPS/POPS... Key West 88 79 88 79 / 20 30 40 40 Marathon 87 79 88 79 / 20 30 40 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Small Craft Advisory until 5 PM EDT this afternoon for GMZ052>055- 072>075. && $$ |
| #1182638 (Received by flhurricane at: 8:51 AM 01.Jun.2024) AFDKEY Area Forecast Discussion National Weather Service Key West FL 447 AM EDT Sat Jun 1 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 112 AM EDT Sat Jun 1 2024 Currently - A surface high centered over the Mid-Atlantic is driving fresh easterly breezes across the Keys. As a result, for the first time in what seems like forever, robust easterly has spread across the Keys. Winds along the reef are gusting to 20 to 25 knots. Dry air and short wave ridging has kept largely stable conditions across the area and shower activity has been quite limited through the night. The healthy flow has given the Keys an infusion of modified continental air. As a result, temperatures are in the lower 80s with dew points broadly near 70. Forecast - The previously mentioned high cell will continue to drive southeastward into the Atlantic over the next couple of days. As a result, initially fresh easterly breezes today will gradually relax through the remainder of the weekend and into early next week. Another day or so of mild conditions will continue due to state of the modified continental air. Rain chances, however, will begin trending upwards. This will be due to the shortwave ridging aloft moving through and weakening as it gives way to incoming southern stream troughing. While island cloud lines are possible today, conditions will be quite a bit more favorable on Sunday. The high cell that moved off the Atlantic coast will weaken as it elongates out into the Atlantic early next week. As a result, surface winds will relax. The lengthening and warming maritime streamlines will result in further moderation of the incoming air. As a result, expect temperatures to nudge upwards closer to 90 while dew points creep back into the mid 70s. Meanwhile, mid level troughing is expected to persist, despite the upper level flow becoming zonal. The combination of the above justifies holding at least chance pops. Uncertainty ramps up from mid week and beyond. Guidance has been suggesting that a nearly cut off southern stream shortwave trough will roll across the Gulf of Mexico, on its way across Florida. This would normally spell higher rain chances. However, the region with the best lower level moisture is expected to remain well to our southeast. This will be in response to a new high cell advancing southeastward off the Atlantic coast. In addition, as the ridge slips down the Florida peninsula, the steering flow and low level forcing will weaken. For now, guidance is middling regarding rain chances. && .MARINE... Issued at 112 AM EDT Sat Jun 1 2024 High pressure over the Mid-Atlantic will roll southeastward off the coast over the next couple of days then push eastward into the Atlantic. As a result, moderate to fresh easterly breezes will gradually trend downwards. A Small Craft Advisory will likely be required, at least initially, as winds remain up. Moderate ridging will remain stretched across the southeast and Florida through the first half of the week. This will keep breezes light and broadly out of the east. && .AVIATION... (06Z TAFS) Issued at 112 AM EDT Sat Jun 1 2024 Breezy, VFR conditions will prevail at EYW and MTH through the upcoming TAF period. Near surface easterly winds will stabilize between 10 and 15 knots with occasional gusts near 20 knots. Hi- res models suggest potential shower development near noon near EYW and MTH, prompting VCSH in the TAF. && .CLIMATE... On this day in day in Keys Weather History, the daily record low of 65F was measured at Marathon in 1955. This measurement tied for the coldest temperature ever recorded in the month of June. Temperature records at Marathon date back to 1951. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Small Craft Advisory for GMZ031>035-042>044-052>055-072>075. && $$ |
| #1182597 (Received by flhurricane at: 2:21 AM 01.Jun.2024) AFDKEY Area Forecast Discussion National Weather Service Key West FL 1018 PM EDT Fri May 31 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 917 PM EDT Fri May 31 2024 KBYX is mostly quiet at this time, but it`s worth mentioning that there are some outflow boundaries still moving across our forecast area from earlier thunderstorms that came off of the peninsula. These could lead to intermittent, short-lived showers over the waters west of the Marquesas Keys. Along the Reef, surface observations are showing fresh northeast to east breezes. The good news is that the air constantly moving keeps things from feeling stagnant, and it is certainly welcomed when our temperatures are currently in the mid to upper 80s. If there is a silver lining, dew points are still trying to creep closer to the lower 70s, but some observations are still showing values in the mid 70s. Overall, this isn`t the most uncomfortable night, but we would probably enjoy it more if we could knock a few degrees off of both the temperatures and the dew points. The OOZ sounding has calculated a PWAT value of 1.22", which is between the 10th and 25th percentile, telling us that this is relatively dry air for this time of year. The swath of drier air is also reflected in the CIMS MIMIC product, which is showing PWAT values around 1.30" to 1.40", give or take a few hundredths of an inch. The combination of the relatively drier air, and a wind profile unfavorable for any activity have resulted in the quieter conditions along the Florida Keys this evening and should allow for these quieter conditions to continue overnight. There are no changes or updates needed to the current forecast package at this time as everything remains on track. && .MARINE... Issued at 917 PM EDT Fri May 31 2024 Small Craft Advisory is in effect for all the Florida Keys coastal waters tonight for northeast to east winds of 20 to 25 knots and seas up to 7 feet in the Straits of Florida. From synopsis, high pressure over the Ohio Valley will dive southeastward, emerging off the Mid- Atlantic coast over the weekend. This will result in freshened northeast to east tonight, lasting through much of the weekend. && .AVIATION... (00Z TAFS) Issued at 917 PM EDT Fri May 31 2024 VFR conditions will prevail at both island terminals through the TAF period. At EYW, near-surface easterly winds at the beginning of the period will continue to gust near 20 knots, but will diminish temporarily between approximately 08Z and 12Z before gusts of near 20 to 25 knots resume. However, MTH will continue to see gusts up to near 25 knots at times. A mix of showers and thunderstorms may approach the island chain at times during the TAF period, but there is low enough confidence with respect to where the best chances for storms are, so VCSH is in the later end of the TAF but it is difficult to say if this will turn into any onsite weather indicator. && .CLIMATE... On this day in day in 1871, the daily record rainfall of 2.81" was recorded in Key West. && .PRELIMINARY POINT TEMPS/POPS... Key West 80 88 79 88 / 20 20 30 40 Marathon 80 87 79 88 / 20 20 30 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Small Craft Advisory until 5 AM EDT Saturday for GMZ031>035- 042>044-052>055-072>075. && $$ |
