textproduct: Melbourne

KEY MESSAGES

Issued at 1222 AM EST Wed Nov 11 2026

- There is a 30-40% chance of rain and widely scattered storms today, with the greatest coverage south of Orlando to the Treasure Coast in the afternoon and evening. A low, conditional threat for a strong to severe storm exists, with gusty winds from 50-60 mph and up to quarter-size hail as the primary hazards.

- A strong cold front will pass through the area on Thursday night, with cooler temperatures from Friday into Saturday. Early morning wind chills have a 10-15% chance to briefly dip into the upper 30s from Orlando northward on Saturday morning.

- Extensive flooding continues along the St. Johns River due to exceptional rainfall in the upper reaches of the basin last week. We are monitoring a low potential for heavy rainfall along the coast next week. The latest river forecasts are available at water.noaa.gov/wfo/MLB.

DISCUSSION

Issued at 1222 AM EST Wed Nov 11 2026

-----------Synoptic Overview-----------

A split flow regime persists over the Eastern U.S. Of immediate concern for Central Florida is the subtropical jet extending along the Northern Gulf Coast, and specifically an embedded shortwave over the Ark-La-Tex region. This disturbance is forecast to move eastward today. As it reaches N Fla by evening, the environment will become more favorable for synoptic-scale ascent.

Moisture is slowly returning, evidenced by scattered returns on KMLB radar. By this afternoon, PWAT values are forecast to jump to 140% or more of normal from near Orlando and especially southward. Relatively steep mid-level lapse rates are also expected, contributing to moderate instability over the southern half of the peninsula later today. Finally, the nearby jet should provide effective shear of 30-40 kt. By Thursday, thermodynamics will become less favorable for deep convection as deep moisture is slowly pushed southward.

Meanwhile, the polar jet is beginning to amplify. Transient but stout high-latitude blocking has developed this morning, with well-above-normal 500 mb heights from the Northwest Territories to Greenland. High confidence persists that meridional upper flow will overtake the nation late this week and through much of the weekend. Deep troughs are expected to form over the Eastern U.S. and just off the Pacific Coast as a ridge builds over the Rockies. On the leading edge of the developing trough over the East, low pressure will strengthen as it passes from the Ohio Valley to the Mid-Atlantic through late Thursday. Its trailing cold front should pass through Florida on Thursday night.

Cold, continental high pressure should build southward out of Canada on Friday. Chilly northwesterly flow will develop over the Southeast and Florida from Friday into Saturday, allowing 925 mb temps to fall to between +6 and +11 deg C as PWATs tumble to 30% of normal by early Saturday. The cold, East Coast trough should slowly weaken and push toward the Canadian Maritimes by early next week. High pressure follows close behind, with a deepening layer of brisk onshore flow resuming from Sunday into early next week. This will quickly reverse the cold advection and begin a moderating trend over the peninsula.

The Pacific jet is expected to remain active with multiple disturbances reaching the West Coast over the next several days. As the high-latitude block breaks down, the pattern is likely to become progressive next week. At least half of the physics-based ensemble members, along with the ECMWF-AIFS mean, suggest one of these features will undercut a ridge over the High Plains and reach the Southeast U.S. by Monday or Tuesday. Modest moisture advection is also anticipated, suggesting a return to unsettled conditions by that time.

Ensemble agreement and forecast confidence are high through the weekend but decrease into next week.

-------Sensible Weather & Impacts-------

Today - Tonight...

A weak disturbance sparked a few showers last evening and early this morning, but this activity should be pushing off into the Atlantic. Except for isolated showers, we expect generally quiet conditions through early afternoon.

As mentioned in the overview, at least marginally favorable parameters will exist for storm development this afternoon and evening, especially south of Orlando to the Treasure Coast. The question will be whether an area of forcing associated with the subtropical jet will effectively overlap with the deeper moisture and instability. Guidance handles this with 30-40% rain and storm chances late in the day.

If storms can manage to form, there is still a low and conditional strong to severe storm threat. With nearly unidirectional wind profiles, gusty winds to 50-60 mph and hail to around quarter size would be the primary hazards. Locally, heavy rain will occur beneath the storms, but overall storm motions should mitigate a flooding risk.

Highs today will be the warmest of the next week or so, generally in the low to mid 80s. Most areas should return to dry conditions later tonight with mild temps persisting.

Thursday - Friday...

Moisture gets squeezed southward on Thursday as westerly flow mixes down some drier air across the northern half of the state. Shower chances (20-40%) are relegated to the Treasure Coast. We expect quite a bit of cloud cover as a cold front approaches. Highs should reach 75-80 degrees.

The cold front makes its pass through Central Florida on Thursday night. By Friday afternoon, it will be well south of here. Clearing skies are forecast on Friday, with temps trending below normal in the low to mid 70s. Breezy northwest winds will develop with gusts 15-25 mph.

Weekend...

Temperatures more typical of January will be felt across Central Florida by Saturday morning as northwest winds deliver cooler air down the peninsula. Low temps should reach the mid to upper 40s over much of the interior, with low to mid 50s at the immediate coastline. Our coldest wind chills are forecast near and north of Greater Orlando (low/mid 40s). There is still a 10-15% chance of wind chills briefly touching the upper 30s over this same area.

Onshore flow may return slightly faster than previously expected, so temperatures have actually trended slightly milder from Saturday afternoon into Sunday. Highs Saturday are now forecast to reach the mid 60s to low 70s, with lows Sunday morning mainly in the 50s, except some upper 40s northwest of I-4. We should all return to the 70s on Sunday.

Partly cloudy to mostly clear skies are forecast this weekend.

Monday - next Wednesday...

Temperatures continue to trend milder, especially for overnight lows, as we move into next week. Onshore flow is forecast to become quite breezy off the Atlantic, which is likely to cause rough surf and hazardous beach conditions.

Guidance has hastened the return of moisture, and with another disturbance approaching, rain chances will increase through the period. It remains too early to tell whether heavy rainfall will occur, but trends should be monitored closely. Reasonable worst-case rainfall tallies (roughly a 1-in-10 chance of occurrence) have ticked up to 3-4" along the immediate coast between Monday and next Wednesday night.

MARINE

Issued at 1222 AM EST Wed Nov 11 2026

High pressure settles southward today, with light offshore flow developing. A disturbance is forecast to spark scattered storms, some of which may be gusty and offshore-moving. A cold front reaches the area by Thursday night. Behind it, winds freshen and turn northwesterly from Friday into Saturday. Poor to hazardous boating conditions are expected during this period. Strong high pressure to the north of Florida will turn winds back onshore by Sunday.

SW winds 5-10 kt today, becoming W 10-15 kt on Thursday. Behind the cold front, winds on Friday and Saturday turn NW to NNW 15-20 kt, briefly up to 25 kt offshore of Volusia County, especially early Friday. Seas 2-4 ft through Thursday, then 2-4 ft nearshore / 3-6 ft offshore on Friday and Saturday. Locally, 7 ft seas are possible in the Gulf Stream behind the cold front.

AVIATION

(12Z TAFs) Issued at 620 AM EST Wed Nov 11 2026

Few light showers possible almost anywhere this morning. Continued light/variable winds thru the morning hours with an offshore (SW/W) wind component developing by afternoon 5-10 kts. An increase in moisture combined with a disturbance aloft will promote ISOLD-SCT convection this afternoon and early evening focused mainly south of a KTIX-KISM line. A few strong storms will be possible toward Okeechobee and the Treasure Coast terminals later today where moisture is deepest. Have inherited VCTS from MLB southward beginning around 18-19Z and will consider TEMPOs as confidence allows. Generally VFR conds, but could see MVFR invof convection.

FIRE WEATHER

Issued at 1222 AM EST Wed Nov 11 2026

Minimum RH values will remain above 45-55% through at least Thursday. A cold front passes by on Thursday night, delivering cooler and drier air from Friday into Saturday. RH minima as low as 38-45% are forecast on Friday near and northwest of I-4, with widespread RHs of 40-45% on Saturday. Northwest winds of 8-12 mph are expected Friday, turning NNW around 10 mph on Saturday. Moisture will begin to increase from Sunday into next week as winds become onshore.

HYDROLOGY

Issued at 1222 AM EST Wed Nov 11 2026

River flood warnings remain in effect for all St. Johns River forecast points (Cocoa, Geneva, Sanford, DeLand and Astor). River levels are forecast to continue holding steady or slowly rise over the next several days. Specifically, the river west of Cocoa (COCF1) is within Major Flood Stage, with other points within or forecast to reach Minor to Moderate flood stage. River forecasts out five days are issued twice daily by the NWS Southeast River Forecast Center in collaboration with NWS Melbourne and are available at water.noaa.gov/wfo/MLB.

While a few storms may develop through this evening, widespread heavy rain is not forecast. There is a 10% chance of localized rainfall amounts exceeding 1/2" along the Space and Treasure Coasts. The next significant rain chance should then hold off until early next week. While it is far too early to determine whether the setup will be favorable for heavy rainfall, the upper-end of guidance shows a low chance (10%) of 3-4" along the coast early to mid next week as onshore flow pulls moisture back over the area and a disturbance approaches from the west. We will continue to monitor this setup and any potential implications for ongoing flooding.

PRELIMINARY POINT TEMPS/POPS

DAB 82 60 80 57 / 20 10 0 0 MCO 82 63 79 61 / 10 0 0 0 MLB 83 64 79 63 / 30 10 0 0 VRB 85 63 80 63 / 50 30 0 0 LEE 82 60 79 57 / 30 0 0 0 SFB 83 61 80 58 / 10 0 0 0 ORL 82 62 79 59 / 10 0 0 0 FPR 84 64 79 63 / 40 40 10 0

MLB WATCHES/WARNINGS/ADVISORIES

FL...None. AM...None.