textproduct: Jacksonville

KEY MESSAGES

For the latest NE FL and SE GA Daily Key Messages please visit: https:/www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

- Freeze Warning for Portions of Inland Southeast GA This Morning

- Small Craft Advisory For Area Waters Today

- Freeze Watch and Widespread Frost for Inland Southeast GA and and inland Northeast Florida late Tonight/Wednesday Morning

NEAR TERM /THROUGH TONIGHT/

Main Highlights through Tonight:

- Light Freeze/Patchy Frost this morning inland Southeast Georgia.

- Light Freeze/Widespread Frost possible late tonight/sunrise Wednesday morning inland SE GA and I-10 corridor of North FL.

This morning: Strong cold air advection ongoing behind the frontal passage with clearing skies and gusty NW winds around 15 mph with gusts to 25-30 mph. These winds will fade slightly towards morning as temps plunge into the 30s over all inland areas towards sunrise, and still expect a light advective freeze across inland SE GA to the NW of Waycross and will keep Freeze Warning in place for now, while temps fall to around 40F at the Atlantic beaches. These winds combined with the cold temps will still drive wind chills into the upper 20s/around 30F, but still slightly above any Cold Weather Advisory criteria.

This afternoon: Cold air advection weakens slightly with NW winds falling to around 10 mph with a few remaining gusts to 15-20 mph. A few periods of mid/high clouds will also aid in holding Max Temps to well below normal levels with highs only in the 50s, which will be slightly above record low Maximum temps for March 17, included here...

JAX 54/2005...CRG 56/2005...GNV 54/1901...AMG 46/2005

Tonight: Cold high pressure builds just North of the region into GA and the Carolinas and expect mostly clear skies to develop along with much lighter North winds to develop at 5 mph or less over inland areas, but closer to 10 mph along the Atlantic Coast. This pattern supports much below normal temps along with the potential for a light Freeze/Widespread Frost for all of inland SE GA and along the I-10 corridor of inland North FL from JAX westward. Due to the warm bias of NBM temps in these situations, have expanded the Freeze Watch eastward to the I-95 corridor in SE GA and southward to the I-10 corridor in North FL to account for a possible light Freeze as the warm up in late Feb/early March has led to quite a bit of a green-up in vegetation over the past 2 weeks, so want to get the message out that sub-freezing temps will be possible. A Frost Advisory may be required for other portions of inland NE FL along the I-75 and US 301 corridors where temps down into the middle 30s for the GNV/OCF metro area will be possible, but will let the day shift finalize any Freeze Warning and place the counties around this into a Frost Advisory. Overall low temps will be near record levels in the upper 20s/near 30F across inland SE GA and lower 30s along the I-10 corridor of inland North FL and middle 30s for the rest of inland NE FL. The slight onshore component to the winds will hold the Atlantic Coastal areas around 40F. Record Low Minimum temps for March 18 are listed here...

JAX 32/1971...CRG 37/1978...GNV 29/1962...AMG 30/1971

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

Main Highlights This Period Wed-Thu:

- Below normal temperatures and dry conditions

A large mid to upper level trough, slowly shifting eastward, will dominate the eastern U.S. this period. A large upper ridge will be slowly moving east over the southwestern U.S. This pattern will favor northwest flow aloft, dry conditions, and quiet weather for us and temps will slowly warm up by Thursday, but largely remain below normal. At the sfc, a high pressure ridge will dominate the area with the axis from the Carolinas southwest into the Gulf. There will be a shortwave wave trough passing overhead Wednesday night which will help produce a sfc trough offshore, along with a few marine showers, and tighten the pressure gradient near the coastal areas for early Thursday.

After a cold start on Wednesday morning, highs reach around 60 deg north zones to upper 60s southern areas. Cool at the coast around 60, due to northeast winds of up to 10-15 mph.

Not as cold Wednesday night but still cold temps ranging from mid/upper 30s inland from Suwannee Valley northward, and then lower 40s toward the coast. Patchy frost looks possible for inland southeast GA late Wednesday night given the mid 30s temps, light/calm winds, and mid/high clouds clearing by sunrise Thursday. Temps warm up to upper 60s north to lower 70s for Thursday, cooler at the coast due to northeast winds of up to 10-15 mph.

Other than some mid to high clouds associated with the shortwave trough mentioned previously for Wednesday into Wednesday night, skies look mostly clear.

LONG TERM /FRIDAY THROUGH MONDAY/

Main Highlights This Period: Friday to Monday.

- Warming trend continues this period and remains dry

While the deep mean trough shifts away from the area, a weak shortwave in the northwest flow drops in over the mid Atlantic and southeastern U.S. At the surface, an associated weak cold front will eventually make its from the northeast U.S. to the Carolinas to north GA by Monday. Locally, the surface ridge axis over the region on Thursday will shift slowly southward through the weekend and early next week. Thus, we will see the wind profile veer in response to this pattern. With the winds shifting to the southwest over the weekend, there is potential for late night and early morning low stratus and fog. However, conditions will remain dry during the period, but there are a handful of ensemble solutions showing low precip chances possible for north and central zones on Monday- Monday night as the front moves toward our region. Maintaining just 10 percent POPs for now Monday. Otherwise, high temps trend from highs in the 70s to the 80s over the weekend and into Monday. Lows from 45-55 Fri morning to mostly 50s for lows into Monday.

AVIATION /06Z TUESDAY THROUGH 06Z WEDNESDAY/

VFR conds are expected this TAF period. Main impact will be gusty NW winds at 10-15G20 knots for the first 6-12 hours, then winds becoming light out of the North less than 10 knots the remainder of the period.

MARINE

Small Craft Advisory conditions continue as a strong cold front moves south of the waters this morning with gusty northwesterly winds and elevated seas. Winds subside and shift to northerly this afternoon and then northeasterly by Wednesday as high pressure shifts northeastward towards the Mid-Atlantic coast. This strengthening high pressure center will wedge down the southeastern seaboard later this week, creating another round of Small Craft exercise caution conditions on Wednesday night and Thursday. Winds and seas are expected to diminish by Friday afternoon.

Rip Currents: A moderate risk of rips is expected in the offshore flow today with surf/breakers 2-3 ft, then a shift to more of an onshore flow on Wednesday will continue a Moderate risk with surf in the 2-4 ft range, then potential for a high risk by Thursday with a stronger NE wind surge pushing surf/breakers into the 3-5 ft range.

FIRE WEATHER

- Areas Of High Daytime Dispersion Today - Areas Of Critically Low Min Rh Today Through Thursday

Cooler and drier air will dominate the area today through Wednesday with high temperatures slowly continuing to trend upward rest of the week. Breezy northwest winds expected through this afternoon with areas of high daytime dispersions mainly to the north of I-10. With the drier air filtering into the area, critical min RH values will be present today and persist through Thursday. High pressure overhead midweek, will bring weaker winds area-wide on Wednesday, allowing for lower dispersions to develop.

FOG POTENTIAL AND OTHER REMARKS: Significant fog potential is not expected the next couple of days. A light freeze expected for portions of inland southeast Georgia this morning, with more confidence in a freeze and widespread frost tonight to early Wednesday morning.

PRELIMINARY POINT TEMPS/POPS

AMG 54 28 57 35 / 0 0 0 0 SSI 55 39 58 46 / 0 0 0 0 JAX 58 34 62 42 / 0 0 0 0 SGJ 57 40 62 48 / 0 0 0 0 GNV 58 33 66 40 / 0 0 0 0 OCF 59 34 67 42 / 0 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Freeze Watch from late tonight through Wednesday morning for FLZ021-023-024-030-120-220-322-422-425-522. Frost Advisory from 4 AM to 9 AM EDT Wednesday for FLZ031-035- 136-232-236-237-240-340. GA...Freeze Watch from late tonight through Wednesday morning for GAZ132>136-149-151>153-162-163-165-250-264-350-364. Freeze Warning until 8 AM EDT this morning for GAZ132>135-149. MARINE...Small Craft Advisory until noon EDT today for AMZ450-452-454. Small Craft Advisory until 3 PM EDT this afternoon for AMZ470- 472-474.