Miami, Florida

New AVIATION

• Moderate coastal flooding remains possible through at least Sunday. Inundated roadways along coastal areas will be possible during times of high tide.
• Dangerous marine and beach conditions are expected across the Atlantic coast.
• Slight Risk (level 2/4) for heavy rain leading to isolated flash flooding Sunday afternoon through Monday morning.

Deep layer ridging covers the Southeast and much of the center of the country, with a shortwave over eastern TX and the Lower MS Valley. Ensembles generally bring the shortwave through the Southeast overnight tonight through Monday morning, and only gradually nudge the low-level ridge axis northeastward. Then, ridging briefly builds back over the Southeast before a stronger frontal system reaches and crosses through the Southeast mid to late week.

The continued strong easterly flow at the base of the low-level ridge will keep the coastal trough in place and allow for scattered showers to move inland today and tonight. While the probability of rainfall across south Florida is high, the scattered nature of the showers makes it difficult to pinpoint where and when a location may be impacted by a passing shower. The one thing hi-res guidance does agree on is that the highest probability of heavier rainfall is in the late night/early morning hours (within training bands) with mostly light to moderate showers during the daytime. Additionally, with the exception of any training, showers should be rather brief since the steady easterly flow is expected to keep showers moving quickly.

The deep-layer forcing associated with the approaching shortwave is forecast to arrive late Sunday afternoon into the overnight hours. The primary expectation is more widespread rainfall with the assist from the large-scale ascent and high PWATs. With the low-level easterly flow expected to continue (and the associated trough remaining in place), the pattern of west-east oriented bands of heavier precip will likely continue but be enhanced by the support aloft. For these reasons the WPC has outlooked much of the Florida east coast with a Slight Risk for excessive rainfall on Sunday. Essentially this is a level 2/4 risk for isolated to scattered flash flooding potential. On average across South Florida, a reasonable worst case QPF would be on the order of 1.5-2", but wherever an W/E oriented band sets up, the reasonable worst case jumps closer to 3-5". With those amounts likely to fall over the course of 1-3 hours, there would be a slight flash flooding risk. Since this risk runs through the overnight hours Sunday, into early Monday morning, WPC keeps the FL east coast under a Slight Risk in Monday`s outlook as well.

For the first part of next week we return to a pattern consisting of ridging aloft and moderate easterly flow around the base of a low-level ridge. That means a return to scattered passing showers each day and night. The pattern will change a bit come mid-week when flow begins to veer ahead of a developing/approaching frontal system. There`s still quite a bit of uncertainty around the pre-frontal environment and how mesoscale features will affect storm distribution each day, but guidance is in fair agreement of a frontal passage some time on Friday. How strong and how far south the surface low will be, and what that means for the potential for an isolated severe storm or two, remains in question with quite a bit of model spread. Certainly something to keep an eye on once we get past this weekends heavy rain threat.

Periods of lower cloud decks and passing showers will continue to bring MVFR cigs/vis through 00Z, and likely through the overnight hours. ENE winds will generally range between 10 to 15 kts with gusts of 20 to 25 kts possible throughout the TAF period.

Scattered showers with embedded thunderstorms will become numerous on Sunday, with possible periods of MVFR/IFR at all terminals.

Winds across the local Atlantic waters will increase through the morning, with gusts reaching the 20-25 kt range, while seas will build up to 7-10 ft (by late tonight) along the Gulf stream. Conditions across the Gulf will remain below hazardous criteria, but will need to be monitored closely. These impacts could last through the rest of the weekend as the stout pressure gradient and breezy easterly northeasterly winds prevail. Isolated showers remain possible today, with more widespread rain chances late this weekend.

Persistent and strong onshore flow will keep a high risk of rip currents in place for the foreseeable future. Additionally, the strengthening winds and building seas will result in surf heights reaching advisory levels by this afternoon along Palm Beach and Broward beaches.

Though we`re on the back side of the King Tide peak, water levels are struggling to fall below moderate stage during high tide cycles due to the persistent, and at times strong, onshore flow. There may be a brief window where we`re able to fall below moderate flood stage late Sunday through Monday, but once the easterly flow becomes established again early next week, guidance indicates the potential to flirt with moderate flood stage once again. We certainly won`t be dealing with the levels seen during the peak of the King Tides, but a prolonged period of at least minor impacts at high tide should be expected through much of next week.

Miami            76  82  74  83 /  60  90  80  80
West Kendall     76  84  74  84 /  50  90  80  80
Opa-Locka        75  83  73  84 /  60  80  80  80
Homestead        76  84  74  85 /  60  90  80  80
Fort Lauderdale  75  81  73  82 /  70  90  90  90
N Ft Lauderdale  75  82  73  82 /  70  90  90  90
Pembroke Pines   75  84  73  84 /  60  90  80  90
West Palm Beach  75  82  72  82 /  50  70  80  90
Boca Raton       75  82  73  82 /  60  80  90  90
Naples           73  84  71  84 /  20  80  60  60

FL

Coastal Flood Advisory until 7 PM EDT Sunday for FLZ168-172-173.

High Rip Current Risk through Monday morning for FLZ168-172-173.

High Surf Advisory until 7 AM EDT Monday for FLZ168-172.

AM

Small Craft Advisory until 7 AM EDT Monday for AMZ650-651-670-671.

GM

None.