National Weather Service Raw Text Product

748 
FXUS62 KMFL 121906
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
306 PM EDT Wed Apr 12 2023

...New SHORT TERM, LONG TERM, MARINE, BEACHES...

.SHORT TERM...
(Rest of today through Thursday)
Issued at 237 PM EDT Wed Apr 12 2023

Mesoanalysis indicates that the warm front has gradually lifted 
northward over the last several hours, with robust convection firing 
along the boundary courtesy of enhanced localized ascent. 
Precipitable water values remain roughly around 1.7 to 1.8 inches, 
with the 12z MFL sounding showing a classic skinny CAPE with a deep 
warm cloud layer. To the north of the warm front boundary across our 
area, ongoing isentropic ascent has resulted in light to moderate 
shower activity developing and "filling in" on KAMX to the north of 
the convection directly along the boundary. Impressive rainfall 
totals over the last several days across portions of Miami-Dade and 
Broward counties have result in saturated soils and primed 
antecedent conditions. Flash Flood Guidance (FFG) demonstrates this 
well as the 1 hourly FFG rainfall rates are about 1.5 to 2 inches 
across Miami-Dade County. With the propagation of heavier convection 
across these same areas over the next several hours, the flood 
threat will gradually increase over the next several hours and 
remain through the afternoon hours. While forecast QPF guidance from 
the Weather Prediction Center indicates the potential of 2-4 inches 
of additional rainfall across Miami-Dade and Broward counties, some 
ensemble members have indicated the potential for locally higher 
amounts. Especially across portions of coastal Miami-Dade county 
where the boundary will remain situated for much of today. The CAM's 
(Convection Allowing Models) also pick up on the potential of a few 
localized pockets of higher rainfall amounts.

On the convective side of the house, the 12z MFL upper air sounding 
from earlier this morning indicates some gradual turning with 
height. Given the addition of enhanced vorticity along the warm 
front boundary, waterspouts could be possible across our local 
offshore waters where instability is more conducive. If strong 
convection is able to develop overland, elevated winds in the 970-
925mb layer could mix down and result in gusty winds at the surface. 
The main concern today will remain the flooding risk, with the 
potential of flash flooding if heavy rainfall persists for a long 
duration. 

Given widespread convection and breezy winds, temperatures will 
remain in the upper 70s today. 

The deeper moisture lifts north of the area tonight, and hi-res 
models are in fairly good agreement for a break in the rainfall 
overnight into early Thursday morning, but will keep chance showers 
and isolated thunderstorms in along the east coast. Deeper moisture 
returns across South FL during the day on Thursday as the warm front 
finally starts to lift north across the area, which will result in 
more scattered showers and thunderstorms, this time with the highest 
PoPs around the lake region and the northern east coast metro. Will 
again have to watch for some flooding issues if heavy rain falls 
repeatedly over the same areas.

With more sunshine and diurnal heating, high temperatures on 
Thursday will reach the low to mid 80s across most of the area with 
a few inland locations reaching the upper 80s.

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 237 PM EDT Wed Apr 12 2023

The mid level cut off low will gradually be lifting northeastward 
through the Tennessee Valley and into the Midwest and Great Lakes
region on Friday. This will allow for mid level heights to rise as
some ridging tries to build into the region during the first part
of the weekend. At the surface, the area of low pressure will 
also move northeastward away from South Florida and it will take 
the deep layer moisture along with it. There will still be enough
residual moisture in place to support a chance of shower and
thunderstorm development on Friday in the afternoon with the sea
breeze boundaries interacting with each other. As high pressure
tries to build in for the first half of the weekend, most of South
Florida will see dry conditions on Saturday. High temperatures on
Friday and Saturday will generally remain in the mid 80s along the
coastal areas to the upper 80s over the interior sections. 

Moving into the second half of the weekend, the latest ensemble
guidance shows an amplifying trough in the Northern Plains 
digging towards the southeastern portion of the country. At the
surface, another cold front will push into the southeastern
portion of the country and into the Florida Peninsula on Sunday.
As this front pushes closer to the region, moisture will increase
allowing for the chances of showers and thunderstorms to increase
on Sunday afternoon into Sunday night. High temperatures will
remain on the warm side out ahead of the front on Sunday as they
will rise into the upper 80s to around 90 across most areas. 

The latest model guidance shows the front slowing down as it moves
through the region, eventually stalling out just to the south
across the Florida Straits on Monday. This will allow for 
moisture to linger over the region during the early portion of 
next week keeping the chances of showers and thunderstorms in the
forecast during this time frame. High temperatures early next 
week will generally range from the lower 80s across the east coast
metro areas to the mid to upper 80s across the interior portions 
of Southwest Florida. 

&&

.AVIATION...
(18Z TAFS)
Issued at 121 PM EDT Wed Apr 12 2023

VCTS will remain in the forecast for the TAF sites through 00Z
with a tempo group for IFR conditions for ceiling and vis from the
showers and thunderstorms. The winds will remain easterly over the
TAF sites through 00Z before going SE after 00Z. VCSH between 00Z
and 03Z before going dry tonight for the overnight hours.

&&

.MARINE...
Issued at 237 PM EDT Wed Apr 12 2023

East to southeast winds 20-25 kts this afternoon subside to 15-20 
kts by this evening, except for the northern Atlantic waters where 
elevated winds will continue into late tonight. Atlantic seas around 
6-9 feet this afternoon subside to 4-7 feet by this evening.
Gulf seas will gradually subside to 2-4 feet this evening.
SCA was extended through 18Z today for Lake Okeechobee, Biscayne Bay 
and the Gulf waters. The SCA for the Atlantic waters runs through 
00Z this evening for the southern waters and 09Z for the northern 
waters.

&&

.BEACHES...
Issued at 237 PM EDT Wed Apr 12 2023

Strong easterly flow and northeast swell will result in a continued 
high risk of rips for the Atlantic beaches today. Even though the 
easterly flow weakens and becomes more southeasterly on Thursday, a 
lingering swell will still result in a high risk of rips through 
Thursday evening. 


&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            72  84  72  85 /  50  50  20  30 
West Kendall     69  87  68  88 /  40  50  20  20 
Opa-Locka        70  86  71  86 /  50  60  30  30 
Homestead        70  86  70  85 /  40  40  20  20 
Fort Lauderdale  71  83  71  84 /  60  60  30  30 
N Ft Lauderdale  71  83  71  85 /  60  70  40  30 
Pembroke Pines   70  86  71  86 /  50  60  30  30 
West Palm Beach  70  85  70  85 /  60  70  50  40 
Boca Raton       70  84  71  85 /  60  70  40  40 
Naples           70  85  72  85 /  40  40  40  20 

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...Flood Watch until 8 PM EDT this evening for FLZ072-074-172-173.

     High Rip Current Risk through Thursday evening for FLZ168-172-
     173.

AM...Small Craft Advisory until 5 AM EDT Thursday for AMZ650-670.

     Small Craft Advisory until 8 PM EDT this evening for AMZ651-671.

GM...None.
&&

$$

SHORT TERM/MARINE/BEACHES...Hadi
LONG TERM....CWC
AVIATION...BNB