Miami (MFL) — the National Weather Service forecast in plain English · Plaincast

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Cool and dry conditions will prevail across South Florida over the next several days as a strong cold front arrives across the region today.

Breezy northwesterly winds will result in cautionary to hazardous marine conditions across the local Gulf & Atlantic waters this afternoon into Saturday morning.

Short Term

(Today through Saturday) Issued at 140 AM EST Fri Nov 13 2026

The same overall atmospheric configuration looks to remain in place across the Contiguous United States early this morning with a sprawling ridge of high pressure dominating the western half of the country and a potent trough situated over the eastern half. Over the southeastern US, the base of this deepening upper trough (with 500- mb height anomalies near its base over the Southern Appalachians falling within only the 2nd percentile for the date as per the REFS) has united with the strong flow aloft that is associated with the subtropical jet that we continue to have overhead here in South Florida. As a result, an excessively strong jet streak has developed within this area of confluence between the two air currents, encompassing northern and central Florida and extending several hundred miles into the Southwest Atlantic waters, with winds aloft at the 200mb level oscillating between 120 and 130 knots which, according to the REFS, is between the 98 and 99th percentiles for this time of year.

Although South Florida is displaced to the south of this impressive jet streak, the same subtropical jet is still pumping in winds aloft at between 80 and 95 knots, which is between the 92nd and 96th percentiles as per climatology. Embedded moisture along this subtropical jet kept our skies here in South Florida mostly cloudy on Thursday, and recent IR (infrared) satellite imagery continues to suggest the same this morning with an abundance of mid to high-level clouds still streaming across the peninsula from southwest to northeast. Both ACARS and the 00Z MFL soundings support these observations with minuscule dew point depressions in the upper third of the atmosphere and slightly drier air in place across the low to mid-levels.

Taking a look at RTMA-derived surface winds, a weak surface trough can be pinpointed over South Florida's local Atlantic waters with a frail and slackening cold front located a little further south over the Florida Straits. There are showers in association with these two features, mainly confined to their respective axises of surface convergence. Over mainland South Florida, all remains mostly dry as there is little in the way of forcing across the region. The main story recently has been the strong cold front that is expected to bring us our first real cooldown of the Fall season, and you may be wondering, where exactly is it as we speak? Looking off the north towards the borders of Florida, Georgia and Alabama; a sharp demarcation in dew points ultimately reveals the position of the front, as does the presence, via surface plots, of post-frontal northwesterly surface winds over the Florida panhandle and southern GA/AL and southwesterly flow over north-central Florida along and just ahead of the front. This front will continue to work its way down the rest of the Florida peninsula through the rest of the overnight hours, roughly arriving at the Lake Okeechobee region shortly after daybreak Friday morning, which rightfully explains the lack of cooling across South Florida as the air mass we will be waking up to will be still be pre-frontal. We will, thus, be walking our the door Friday morning to lows that will be fairly similar to yesterday morning's, ranging between the mid to upper 60s north of Alligator Alley and in the low 70s across the southern half of the peninsula.

High-res model guidance does suggest that the front could try and squeeze out a few showers as it approaches our region Friday morning and into the first half of the afternoon as it continues to push southward, but chance of rain do not want to exceed 10% in many South Florida locations as it does so. The 00Z MFL sounding showed a measly surface-based storm energy value of just 2 J/Kg, and with model guidance not suggesting it to climb past 500 J/Kg through the rest of the overnight hours and into the morning and early afternoon hours, the risk of scattered showers and let alone thunderstorms will be very low. As per forecast soundings (and the lingering saturation they continue to show in the mid to upper levels), the plentiful cloud cover we have observed this morning is forecast to stay in place through Friday afternoon and should continue to suppress any significant amounts of surface destabilization, thus keeping things rather quiet across South Florida and only resulting in some light stratiform rain here and there as the boundary pushes through our region.

Continental high pressure that, according to surface observations, extends from Manitoba/Ontario in Canada southward through the Midwest and Lower Missouri River Valley will allow winds to become northwesterly later this morning across South Florida amidst our passing cold front. They should be fairly light across mainland South Florida through the majority of the day, before starting to increase over the frictionless local Atlantic and Gulf waters as a local pressure gradient begins to develop between the aforementioned high to the north and the departing front. Since the northern half of South Florida will be the first to experience the intrusion of this much cooler air (in addition to the high cloud cover we are expecting) between the morning and early afternoon hours coinciding with the peak daily heating period, high temperatures will only be climbing into the mid to upper 70s north of Alligator Alley. Will be slightly warmer over the southern half of South Florida ahead of the advancing front, but lingering cloud cover will allow our highs to drop by a few degrees to what we experienced yesterday and achieve values that are closer to average for this time of year (low 80s).

Long Term

(Saturday night through Thursday) Issued at 140 AM EST Fri Nov 13 2026

Brisk upper level flow will remain the atmospheric status quo across South Florida during the second half of the weekend as the sub- tropical jet stream remains entrenched across our region. Model guidance has come into better agreement within the past 24 hours regarding the passage of a shortwave axis across the region during the day on Sunday. However even with the injection of upper level dynamics (Maxima of upper level divergence and low level convergence across South Florida as the region resides in the right entrance of a developing jet-streak), the continental airmass (post-frontal passage) still in place will limit any threat of convective development over land, with an outside chance (<10%) of a few isolated showers developing over the instability laden waters of the Gulfstream. Forecast model soundings depict a dearth of moisture in much of the atmospheric column (above 850-900mb) across our region on Sunday but also reveal a subtle but important shift in prevailing wind direction at the surface. With such a transient mid to upper level pattern increasingly in play across the southern United States, the axis of surface ridging will slide eastwards across the upper Mississippi River valley on Saturday night into Sunday morning. Why is this detail important to us here in South Florida? The siting of surface ridging across the eastern United States is instrumental in determining just how long a "cold" snap is able to last across our region given the moderating influences of the surrounding Atlantic waters. The longer surface flow remains out of a northwesterly direction (Straight from the continent), the longer the duration of a "cold" snap across our area. In this case, the advertised temperature drop for South Florida will be rather short-lived, so be sure to partake (Pumpkin spice anyone?) in this iteration of Florida fall.

As the surface ridge slides eastward, anticyclonic flow on the periphery of the expansive ridge across South Florida is also forecast to veer in direction. nighttime stratification at daybreak is expected to result in light northerly flow across most of the region before surface winds re-couple and veer north-easterly across the region post-sunrise. This could result in an interesting distribution of slightly warmer minimum temperature values along the east coast of South Florida by daybreak on Sunday, while areas across inland southwestern Florida could see values in the upper 40s as surface winds slacken and decouple. The veering of surface winds to a breezy northeast direction during the day on Sunday is forecast to jump-start a gradual warming trend as the airmass in place across South Florida gradually moderates. Forecast high temperatures will range from the upper 70s across coastal locales to temperatures in the mid 70s near Lake Okeechobee.

Ensemble and deterministic guidance continue to depict the next mid- level shortwave sliding southeastward from the Southern Plains into the Lower Mississippi Valley and along the Northern Gulf Coast during the day on Monday. The orientation of the sub-tropical jet stream and a maxima of upper-level divergence out ahead of the short- wave continues to be resolved by model guidance in developing an area of surface low pressure across the western Gulf. While this feature is forecast to remain well to the west of South Florida on Monday, a strengthening pressure gradient (Between the surface low in the Gulf and surface high across the eastern CONUS) is being depicted by model guidance to result in gusty conditions and gradual moisture return across the region on Monday. While the airmass will still be in the process of moderating, gusty NELY to ENErly flow will support the threat of low-topped shower activity moving onshore along the east coast of South Florida during the afternoon hours. High temperatures will also continue on an upward trajectory with forecast high temperatures in the upper 70s to low 80s.

As the mid-level shortwave accelerates southeastward across the northern Gulf during the day on Tuesday, the accompanying area of surface low pressure is modeled to do so in tandem, moving briskly along across the central Gulf. Comparing yesterday's model suite to the latest deterministic and ensemble guidance solutions, the 00z model suite has continued to trend with a more southern trajectory of the mid-level shortwave which would also have direct implications on the track of the associated surface low and frontal boundaries displaced further to the south. Similar to last night, 500mb cluster analysis suggests that ensemble guidance (the European model, GEFS, and CMCE) remains in fair agreement with the placement & timing of the shortwave as variance remains low. The shift southward of the surface low and consequently, best foci of ascent is also represented in expected rainfall cluster analysis with the greatest clustering of ensemble members now depicting the possibility of lower rainfall totals occurring across South Florida than what is depicted on the ensemble mean (GEFS, the European model, and CMCE).

While the latest forecast guidance has trended to a more southern track of the surface low just to the south of South Florida, two other potential trajectories include: 1) a passage directly over South Florida or 2) just to the north of South Florida. The atmosphere is a fluid and forecast alterations are certainly still possible as we remain within the 4-5 day time frame. Lift, instability, and moisture are the three main ingredients for thunderstorm development and will directly be influenced by the exact placement and evolution of the surface low. The fourth ingredient that is needed for more robust thunderstorm development, shear, will be dictated by where the sub-tropical jet-stream maxima is located in relation to surface features.