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

- Elevated Fire Weather Conditions Today Inland NE FL due to Low Humidity, Extreme Drought & Critically Dry Fuels

- Light Freeze & Frost Tonight & Early Sunday.

NEAR TERM /THROUGH TONIGHT/

High pressure continues to build north of the region Today. Clear skies and mild temperatures are anticipated during the afternoon as daytime highs reach into the upper 50s to mid 60s. Northwesterly winds will continue through the afternoon hours, with a light northeasterly sea breeze developing during the afternoon hours along coastal locations.

Clear skies this evening will allow for good radiational cooling during the overnight hours, with sub-freezing temperatures anticipated over inland SE GA and along the I-10 corridor, with a Freeze Warning in place for these locations. The Freeze Watch has been replaced with a Frost Advisory for NE FL locations along the I- 75 corridor and south of the I-10 corridor. Areas to widespread frost is expected to develop due to winds becoming near calm in addition to the sub to near freezing temperatures along the Freeze/Frost warned areas, with patchy frost along north central FL counties and along the I-95 corridor.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Northwesterly flow aloft on Sunday, but a mid to upper level shortwave will approach from the northwest Sunday evening and push through late Sunday night into Monday, and push east of the area Monday night. At the surface, high pressure system around 1029 mb over the Carolinas on Sunday will gradually move south and then southeast of the region Monday into Monday night. Expect mostly sunny skies on Sunday, but increasing mid to high clouds Sunday night into midday Monday as the shortwave trough moves through the area with more clear skies by Monday evening. Conditions will remain dry, however given the very dry low level airmass and winds will remain fairly light during the period. A slow warming trend is anticipated, with highs in the lower to mid 60s on Sunday (which is slightly below normal), and then to the upper 60s and lower 70s on Monday. However, cold lows still anticipated Sunday night falling into the mid 30s inland and lower 40s along the coast with potential for some patchy frost inland. Lows moderate to the 40s on Monday night. The potential for any shallow fog looks pretty low at this time and therefore very limited to well inland areas at this time.

LONG TERM /TUESDAY THROUGH SATURDAY/

A mid to upper level ridge briefly builds over the area Tuesday- Tuesday night and then another shortwave trough approaches and then passes over the region Wednesday. A period of mid to high clouds expected again late Tuesday to Wednesday. Some low chances for showers over southeast GA on Wednesday into Wednesday night given the shortwave, but with weak dynamics and weak low level forcing, not expecting much rain amounts, likely under 0.15 inches. Even lower chances around 10-20 percent for northeast FL on Wednesday. At the surface, high pressure ridge will remain centered over the eastern Gulf, central and south FL through Wednesday. We noted from guidance a new frontal boundary will be moving into the Carolinas Wednesday into Wednesday night. Well above normal max temps Wednesday and Thursday in the mid to upper 70s.

Thursday through Saturday, the aforementioned cold frontal boundary will be sinking southward into the area later part of the forecast, bringing along with it a chance for showers. Latest trends show the front moving into our area on Friday. There are increased chances of showers with this period, especially late Friday and certainly on Saturday as the front begins to stall over north FL and a frontal wave approaches from the west. Still some moderate to high uncertainty on details as model solutions vary on strength, timing, and placement of the frontal wave on Friday night into Saturday. There is moderate to high confidence on above normal temperatures on Thursday around upper 70s, and then moderate to low confidence Friday and Saturday, but certainly Saturday temp trends downward behind the cold front. Ahead of the front Thu and Fri, we could see a few locations that reach 80-82 deg, mainly over northeast FL. Regarding rainfall, it looks like we have a good potential for rainfall totals of at least 0.25 inches over most areas, and the thunder potential is very minimal owing to weak instability (CAPE less than 300 J/kg).

AVIATION /18Z SATURDAY THROUGH 18Z SUNDAY/

VFR conditions prevail through the forecast period. Winds will continue to subside through the afternoon with inland sites around 5-10 kt range, while coastal sites shift to become NE and range around 8-12 kts through 00z as high pressure builds north of the region. After 00z, light northerly winds < 3 kts inland through 12z with ENE to NNE at the coast < 7 kts.

MARINE

Northerly winds drop to Exercise caution levels this afternoon and evening, as high pressure continues to build to the north of the local waters. Northerly winds continue during the overnight hours into Sunday, becoming northeasterly by Sunday morning. Seas will remain at 3 to 5 feet over the waters into the upcoming week. The high builds across south Florida through mid- week.

Rip Currents: Moderate Risk today and Sunday under northerly winds today then northeast Sunday.

FIRE WEATHER

- Elevated Fire Danger Inland Northeast Fl Rest Of Today - Areas Of Low Daytime Dispersions Sunday And Monday - Low Min Rh Values Inland Sunday And Monday

Occasional breezy northwest to north winds expected rest of today with RH values falling to the 25-35 percent range, and 33-45 percent coastal areas.

On Sunday, generally weaker surface and transport winds which also leads to low daytime dispersion. Still some critically low humidity inland as well, generally near and west of U.S. Highway 301.

Outlook: Prevailing dry weather continues Monday to Tuesday with pockets of Min RH values of 25-35 percent inland. Minimum humidity begins to recover further Wednesday and Thursday. No significant precipitation chances expected until late week when a cold front moves into the area.

FOG POTENTIAL AND OTHER REMARKS: Inland frost and freeze expected tonight into Sunday Morning. Significant fog development is not expected.

PRELIMINARY POINT TEMPS/POPS

AMG 32 61 35 67 / 0 0 0 0 SSI 39 55 44 61 / 0 0 0 0 JAX 33 63 39 69 / 0 0 0 0 SGJ 39 63 43 67 / 0 0 0 0 GNV 37 68 38 72 / 0 0 0 0 OCF 37 68 38 72 / 0 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Frost Advisory from 3 AM to 8 AM EST Sunday for FLZ021-030-031- 035-136-232-236-422-522. Freeze Warning from 3 AM to 8 AM EST Sunday for FLZ023-024-120- 220-322-425. GA...Freeze Warning from 3 AM to 8 AM EST Sunday for GAZ132>136-149- 151>153-162-163-165-250-264-350-364. MARINE...None.