801
FXUS62 KKEY 161903
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
303 PM EDT Thu May 16 2024

...New DISCUSSION, MARINE, AVIATION...

.DISCUSSION...
Issued at 219 PM EDT Thu May 16 2024
We are about two weeks away from the beginning of summer, but the
island chain did not get the memo. High temperatures are in the
lower to the mid 90s, and combined with dewpoints in the upper
70s, lends to heat indices in the 100s. Skies are sunny and the
KBYX radar is echo free. Yesterday at this time there were a few
showers on the eastern end of the Lower Keys. It appears the
extremely dry lower levels sampled by the 12Z KKEY RAOB,
corroborated by the SPC mesoanalysis slices, has put the kibosh
on moist congestus.

.FORECAST...
The month of May is typically brutal, with summer-like heat and
slim rain chances to cool off the afternoons. From a
climatological perspective, it is not the driest month. It all
depends on when rainy season turns on. The mesoscale usually kicks
off in June, sometimes earlier, sometimes later (last year). There
is a decent signal for later this weekend or early next week to
start getting some accumulating rainfall.

Synoptically, deep, mean-layer ridging will persist tonight
through Sunday. Forecast soundings and time height cross sections
suggest low-level moisture will struggle, hence the near nil rain
chances through the short term. Near record high temperatures will
remain in play Friday through Sunday. By Sunday night or Monday,
a mid latitude trough will spill around the eastern flank of the
mean layer ridge. The lower heights aloft, confluent lower
troposheric southwesterlies, and the tail- end of cyclonic SFC
flow will introduce a chance of showers and thunderstorms Sunday
night through Monday night/Tuesday. The eventual anticyclonic wave
break to our east will result in a closed low and TUTT transition
near the Greater Antilles. MOS guidance suggests the northerly
fetch Tuesday through Thursday will shave the dewpoints out of the
upper 70s. However, we are getting a little late in the season
for light northwesterlies to be a source of dry air.

&&

.MARINE...
Issued at 219 PM EDT Thu May 16 2024
There are no watches, warnings, or advisories currently in effect
for the coastal waters of the Florida Keys. A weak frontal
boundary to the north of the Florida Keys interacting with an area
of high pressure in the western North Atlantic will result in a
chaotic wind forecast through the weekend. Breezes will tend to
peak in the evening and overnight hours, and then lull in the
afternoon hours.

&&

.AVIATION...
(18Z TAFS)
Issued at 219 PM EDT Thu May 16 2024
The cloud streamers that were evident this morning have been
dissipating this afternoon. However, one main streamer remains
present north of the Middle and Upper Keys with this streamer
extending into the eastern Lower Keys. However, latest visible
satellite imagery shows this starting to drift south towards MTH.
Therefore, while VFR conditions are mostly expected, there may be a
brief period of MVFR CIGs. Near surface winds are expected to remain
southwest to west 10 to 15 knots with occasional gusts to near 20
knots for the next couple hours. Winds will shift to the west to
northwest during the late afternoon to early evening hours as the
cloud streamer moves through before becoming briefly variable this
evening into the overnight hours. Winds will then shift to the
southeast to south during the early morning hours Friday.

&&

.CLIMATE...
On this day in 1923, a daily record rainfall of 2.89 inches was
measured at Key West. May rainfall records for Key West date back to
1871.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  81  92  82  92 /   0   0  10  10
Marathon  81  92  83  92 /  10  10  10  10

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&

$$

Public/Marine/Fire...CLR
Aviation/Nowcasts....MJV
Data Acquisition.....MJV

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