Area Forecast Discussion
Issued by NWS Melbourne, FL
Issued by NWS Melbourne, FL
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792 FXUS62 KMLB 041437 AFDMLB Area Forecast Discussion National Weather Service Melbourne FL 1037 AM EDT Thu Jul 4 2024 .UPDATE... Issued at 1030 AM EDT Thu Jul 4 2024 Early morning Cape sounding shows a pocket of drier air between 850-925mb with slightly lower precip water values of 1.88". This should produce a slower development of the cumulus cloud field until that drier pocket can get mixed out. GOES-16 PW product shows deeper moisture across our north/interior sections and this will be the focus for aftn/eve storms. Sfc analysis shows a very weak pressure gradient over the area supporting light and variable winds which will turn East behind the inland moving sea breeze. Did not need to make significant changes to the forecast for today. Agree that the lowest rain chances will be along the coast esp south of the Cape where isolated showers are possible thru early aftn. Convective initiation should occur across northern sections (Lake/Volusia) this afternoon with a north steering flow producing southward cell motions. So the highest PoPs (60%) are over the north/interior. Storm motion may occasionally be erratic due to propagation along sea, lake, outflow boundaries but generally should be toward the south. Heat Advisory will be in effect through the aftn for peak heat indices 105-110. && .PREVIOUS DISCUSSION... Issued at 430 AM EDT Thu Jul 4 2024 Key Messages: - A Heat Advisory is in effect today for heat index values reaching up to 110 degrees. Residents and visitors should take extra care to stay cool and hydrated. - A High Rip Current Risk is in effect for Volusia and northern Brevard County beaches. Entering the water is discouraged. Elsewhere, a moderate risk for rip currents exists. - Rain and lightning storm chances increase from north to south today along the inland-moving east coast sea breeze. Today-Tonight...Warm and humid conditions are present this morning, along with mostly clear skies. A broad H5 high, stretching from the western Gulf Coast to Florida, will remain in place today. Slightly lower atmospheric moisture is moving onshore across the Treasure Coast and Lake Okeechobee region, as shown by GOES-derived PW imagery. Sub-2 inch PW may briefly work along the rest of the coast, before increasing moisture rotates south again this afternoon. Dangerous heat is expected later today. If you are planning to spend time outdoors to celebrate the holiday, be sure to stay hydrated and take breaks out of the direct sun in air conditioning. Due to the anticipated uptick in moisture this afternoon, temperatures in the 90s will combine to produce heat index values of 105-110 degrees. This level of heat can lead to heat-related illness, especially for those without adequate cooling and hydration. Check up on neighbors and relatives, and remember to never leave children or pets behind in a hot car! If your plans include time at the beach, especially from Cape Canaveral northward, be aware that a High Risk of rip currents exists. Numerous rip current rescues have been reported in the last few days along these beaches, and unfortunately, one rip- related fatality was recorded near Daytona Beach yesterday. Entering the surf is highly discouraged! South of the Cape, including southern Brevard County and Treasure Coast beaches, a moderate risk of rip currents will be present. Here, swim near a lifeguard and never enter the water alone. With respect to rain and storm chances this afternoon, the highest coverage of activity is expected from Daytona Beach/Titusville westward to the Orlando and Leesburg area. Isolated showers are forecast to increase from north to south, in association with greater moisture pushing south over the FL Peninsula. Steering flow will remain light and northeasterly. As the east coast breeze begins to move inland, additional convection is forecast to develop and push west of I-95. Forecast soundings indicate warm 500mb temperatures, between -4C and -5C, which will work to suppress updrafts. However, the atmosphere will be primed with plenty of moisture and instability. This, combined with the sea breeze and other storm-scale boundary collisions, will be enough to set off scattered showers and storms from mid afternoon through early evening. Gusty winds up to 40-45 mph, occasional to frequent lightning strikes, and heavy downpours that lead to minor, short-lived flooding are the main concerns. For those wondering how rain could affect 4th of July festivities, timing and location is key. Showers and storms may linger through sunset, from Lake County south to the Kissimmee River, before gradually dissipating. East of the Orlando area and toward the coast, the forecast calls for drier conditions by sunset. Friday-Sunday...The overall pattern goes largely unchanged late week into the weekend, with mid level ridging overhead and diurnal rain/storms driven by the east coast sea breeze. One hindrance to higher PoPs, especially later Friday through Saturday, will be a lobe of drier air that splits off from a mid level low over the western Atlantic. This pocket of lower moisture looks to stick around through Saturday, especially closer to the coast, keeping the highest rain chances focused inland as the sea breeze advances west each afternoon. Moisture return and southerly flow begins to erode the lower PW on Sunday, helping to reinvigorate rain and storm chances. Daytime temperatures stay hot in the low to mid 90s with heat indices 102-107+. The warmest locations will be inland, and additional heat advisories may need to be considered this weekend into early next week. Nighttime lows only fall into the mid to upper 70s. Monday-Wednesday...Upper level ridging weakens a bit next week but maintains its influence on our weather pattern. As a tropical wave pushes west across the Carribean and Yucatan Monday, relatively lower PWs wrap northward in its wake, across southern FL and the Gulf of Mexico. Nevertheless, near 2" PW hold over north-central FL. Low-level flow over our area becomes more southerly, perhaps even SSW, on Monday and Tuesday. As a result, 40-60 PoP was maintained in the extended period. Confidence lowers somewhat by midweek in rain chances, so PoPs were kept in the chance category Tuesday and Wednesday. Guidance keeps highs in the low to mid 90s through early week, with perhaps a slight downward trend due to rain chances and associated cloud cover. && .AVIATION... (12Z TAFs) Issued at 740 AM EDT Thu Jul 4 2024 VFR conditions are forecast outside of storms with sea breeze driven scattered showers/storms forecast to develop into the afternoon/evening. Isold SHRA possible at SUA-FPR thru 14Z in cloud lines impinging on the coast. VCSH/VCTS begins at 16-19Z with TEMPO TSRA for inland sites from 20-23Z. Shower/storm chances diminish after sunset. Light and variable winds during the overnight/morning will increase from the E at 5-10kts into the afternoon. && .MARINE... Issued at 430 AM EDT Thu Jul 4 2024 Today-Tonight...Generally favorable boating conditions are forecast, outside of daytime isolated/scattered showers and lightning storms. Light and variable winds persist through midday, increasing up to 10 kt and turning onshore with the sea breeze circulation this afternoon. Seas 2-3 ft, perhaps up to 4 ft well offshore. Winds slacken and veer offshore tonight. Friday-Monday...Seas remain 2-4 ft thru the extended forecast. Winds turn out of the NNE Friday and Saturday mornings, veering onshore each afternoon and then offshore at night. Rain and lightning storm chances continue but decrease temporarily for the first half of the weekend. Southerly flow and increased moisture returns Sunday and Monday, helping to expand rain coverage into early next week. && .PRELIMINARY POINT TEMPS/POPS... DAB 92 76 92 75 / 50 10 30 10 MCO 94 77 94 76 / 70 30 50 10 MLB 92 77 91 76 / 40 10 40 10 VRB 92 76 91 75 / 20 10 40 10 LEE 94 78 94 77 / 70 30 60 10 SFB 93 77 93 76 / 60 20 50 10 ORL 94 78 93 77 / 70 30 50 10 FPR 92 76 91 76 / 20 20 50 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...Heat Advisory until 6 PM EDT this evening for FLZ041-044>046-053- 058-141-144-154-159-164-247-254-259-264-347-447-547-647-747. AM...None. && $$ UPDATE...Kelly AVIATION...Fehling