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

- Areas of Dense Fog Possible Late Tonight & Early Saturday Morning, Mainly for Inland Locations Near I-75

- Near Record Warmth Continues through Saturday

- Inland Light Freezes on Sunday and Monday Nights. Widespread Frost Late Monday Night for Inland Locations North of I-10

- Small Craft Advisories Likely Sunday Afternoon through Monday

NEAR TERM /THROUGH TONIGHT/

Afternoon surface analysis depicts strong high pressure (1030 millibars) centered east of Cape Cod, with this feature wedging down the southeastern seaboard. Meanwhile, a cold front extends from the eastern Great Lakes southward through the Ohio, Tennessee, and lower Mississippi Valleys, with a wave of low pressure developing on the southern end of this front over eastern New Mexico and the Texas Panhandle. Aloft...stout ridging positioned over the southeast Gulf and FL peninsula has deflected an initial potent shortwave trough northeastward across the northern Great Lakes, with another potent shortwave trough now emerging over the Southern Plains states from the southern Rockies and the Four Corners region. Latest GOES-East derived Total Precipitable Water imagery indicates that PWATs remain generally in the 1 - 1.25 inch range throughout our area. Deepening south-southeasterly low level flow across our area has scoured out sea fog across the northeast FL waters, with an eroding bank of fog remaining situated over the near shore waters adjacent to southeast GA. A healthy cumulus field has developed elsewhere across our area in the wake of this morning's low stratus and fog episode, as temperatures have skyrocketed to near or above daily record highs, with values climbing to the upper 70s and lower 80s at most inland locations as of 19Z. Lingering low stratus cloud cover and light onshore winds has kept temperatures in the upper 60s to around 70 for coastal southeast GA, while less cloud cover has allowed coastal northeast FL to warm to the mid and upper 70s. Dewpoints at 19Z were mostly in the 60-65 range across our region.

Strengthening southerly low level flow may be able to scour out the remaining remnants of the dense sea fog bank along the southeast GA coast by late this afternoon. Otherwise, deep- layered ridging will remain situated over the FL peninsula tonight, resulting in a slow eastward progress for the aforementioned shortwave trough emerging over the Southern Plains states. This feature will develop a wave of surface low pressure along a lengthy cold front over the lower Mississippi Valley this evening, with this feature then accelerating northeastward towards the Tennessee Valley early on Saturday morning. Surface ridging off the New England coast will gradually weaken overnight as it pushes offshore, placing our area in the warm sector of the upstream storm system, with deepening south to southwesterly flow expected after midnight.

Fog and low stratus developing over Apalachee Bay and the northeast Gulf this evening should advect north-northeastward towards the FL Big Bend region towards midnight, with this fog bank potentially impacting western and northern portions of the Suwannee Valley and eventually interior southeast GA. Gradual veering of the low level flow should keep sea fog offshore of the northeast FL beaches, with some impact possible this evening and overnight for coastal southeast GA. An unseasonably humid air mass should also develop some patches of low stratus cloud cover across the rest of our area towards sunrise. Lows tonight will remain well above average in this warm air advection pattern, with values only falling to around 60 inland and the lower 60s for north central and coastal northeast FL.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/

A cold front pushes through the area during the forecast period as high pressure retreats towards the Atlantic. Prior to the front, above normal temperatures on Saturday as southwesterly flow continues to bring in warmer and moist air in from the Gulf. High pressure builds into the region behind the front.

Dry and warm conditions at the start of the forecast period as southwesterly flow continues through Saturday. Daytime highs will peak in the upper 70s to lower 80s across inland locations, with lower to upper 70s along the coast. Overnight Lows in the 50s area- wide as shower chances begin to increase with the cold front pushing into the region. Showers will steadily push south towards the FL/GA state-line, but will diminish the further south the line travels. Some showers may linger into the morning hours Sunday, but currently the expectation is another mostly dry day on Sunday. Temperatures begin to trend down on Sunday as northwesterly flow behind the front will allow for cooler and drier air into the region. Daytime highs will noticeably be cooler to Saturday as most locations will only reach into the 60s, with the warmer temperatures along the southern portions of the region. By Sunday evening, a return of subfreezing temperatures will allow for a light inland freeze for SE GA, but frost formation will likely be limited as winds will be a bit too windy.

LONG TERM /MONDAY THROUGH FRIDAY/

High pressure continues to build into the region on Monday, beginning to weaken on Tuesday as it shifts towards the Atlantic. Cold temperatures persists at the start of the week. Another freeze is likely Monday evening for inland SE GA as temperatures will again be at or below freezing. Some frost development will be possible as winds will be near calm. Dry conditions prevail through the first half of the upcoming, but a chances of showers return by midweek with models indicating a trough dipping across the FL peninsula and the eastern waters of the Gulf. As the trough moves towards FL, scattered showers are likely to push across FL and north into SE GA on Wednesday/Thursday. Temperatures will be below normal during the period. Thursday night could see the return of sub-freezing temperatures for locations across SE GA and southward into the Suwannee Valley region and along the I-10 corridor in NE FL.

AVIATION /18Z FRIDAY THROUGH 18Z SATURDAY/

Dense sea fog persisting near the SSI terminal will likely continue through at least 22Z, where LIFR conditions featuring ceilings of less than 400 feet are expected. Confidence in prevailing LIFR conditions prevailing at SSI decreases through around 06Z tonight, with most guidance now indicating that dense sea fog will shift north of the terminal during the predawn and early morning hours on Saturday. We maintained IFR conditions at SSI through around 12Z. VFR conditions will otherwise prevail at the regional terminals through at least 06Z. MVFR conditions will likely develop towards 07Z at VQQ, followed by quickly deteriorating conditions by 08Z-09Z. Low stratus ceilings and fog developing over Apalachee Bay tonight could move towards the GNV terminal after 08Z. A period of IFR conditions is expected at GNV from around 09Z-12Z. Confidence was too low elsewhere to indicate sub-VFR conditions, although a period of low MVFR or IFR ceilings will be possible at JAX, SGJ, and CRG towards or just after sunrise on Saturday. Southerly surface winds sustained around 10 knots at the inland terminals will shift to southeasterly at 5-10 knots this afternoon as the Atlantic sea breeze shifts inland. Meanwhile, southeasterly surface winds sustained around 10 knots at the SSI and SGJ coastal terminals will shift to southerly at 5-10 knots after 00Z. Southerly surface winds will then strengthen to around 10 knots at the regional terminals towards 15Z Saturday.

MARINE

Strong high pressure centered off the New England coast will continue to wedge down the southeastern seaboard this afternoon before this feature shifts further offshore in advance of an approaching cold front. Dense sea fog will continue through the early to mid afternoon hours for the near shore waters adjacent to southeast Georgia. Southwesterly winds will gradually strengthen after midnight on Saturday night ahead of the approaching cold front, with winds shifting to westerly and increasing to Caution levels offshore on Sunday morning as the front crosses our local waters. Scattered showers will accompany the frontal passage, with winds then shifting to northwesterly and increasing to Small Craft Advisory levels on Sunday afternoon and night, with occasional gusts to Gale Force possible as high pressure builds over the Tennessee and lower Mississippi Valleys. High pressure will then gradually weaken over the southeastern states on Monday night and Tuesday, allowing winds to shift to northeasterly while gradually diminishing.

Rip Currents: Southeast GA Beaches: Moderate this Afternoon, Low on Saturday Northeast FL Beaches: Moderate through Saturday

FIRE WEATHER

-MinRH values less than 30 percent inland SE GA Sunday through Tuesday -Areas of high dispersions Saturday and Sunday -Areas of low dispersions Tuesday

High pressure will be located to the northeast-east of the region through Saturday. Southwesterly winds will persist through Saturday, becoming breezy as an approaching cold front nears the region, with areas of High dispersions expected on Saturday/Sunday. Along the front, showers are expected to develop and push into the region during late Saturday afternoon through Saturday evening. Some showers may linger into Sunday, but will clear by the afternoon hours as the front clears south of the region. Cold and dry conditions build in behind the front, as Min RH values are expected to drop below 30% from Sunday through Tuesday.

FOG POTENTIAL AND OTHER REMARKS: Areas of fog Tonight, which may become locally dense. Inland Freeze potential Sunday night with an inland freeze and frost inland Monday night.

CLIMATE

Record highs and record high minimum temperatures will be challenged through Saturday at our designated climate sites.

Record High Temperatures:

January 9: KJAX: 83/1974 KGNV: 83/1989 KAMG: 79/1974 KCRG: 81/9999

January 10: KJAX: 82/1957 KGNV: 85/1937 KAMG: 80/1949 KCRG: 79/2014

Record High Minimum Temperatures:

January 8: KJAX: 64/1913

January 9: KGNV: 65/1975

January 10: KGNV: 64/2013

PRELIMINARY POINT TEMPS/POPS

AMG 60 80 54 62 / 0 0 40 10 SSI 60 74 56 66 / 0 0 30 10 JAX 61 82 57 69 / 0 0 10 20 SGJ 63 79 58 70 / 0 0 10 30 GNV 61 84 57 70 / 0 0 10 20 OCF 61 82 57 71 / 0 0 0 20

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...None. MARINE...Dense Fog Advisory until 5 PM EST this afternoon for AMZ450.