textproduct: Wakefield

WHAT HAS CHANGED

Updated aviation discussion for 18z TAFs.

KEY MESSAGES

1) Unseasonably warm temperatures continue, but with limited fire weather concerns expected today, much cooler for the eastern shore, with fog possible along the coast.

2) Showers are likely Sunday, but areal average rainfall amounts continue to look minimal. Fire WX concerns return next Monday in the wake of the cold front, especially if rainfall amounts are minimal.

3) There is the potential for patchy frost and even localized freezing temperatures for inland areas Monday night into Tuesday morning. Then temperatures begin to increase through the middle of the week.

DISCUSSION

As of 325 AM EDT Saturday...

KEY MESSAGE 1...Unseasonably warm temperatures continue, but with limited fire weather concerns expected today, much cooler for the eastern shore, with fog possible along the coast.

Morning weather analysis shows a upper ridge centered over the East Coast with high pressure off the SE coast. Winds have calmed across the area and with mostly clear skies radiational cooling has occurred and temperatures are ranging between the upper 50s to low 60s. Through the rest of the morning there is the potential of low level cloud cover/patchy fog across the Eastern Shore as winds shift out of the SE. Through the day there will be a 30F temperature difference across the CWA due to persistent onshore flow. Between the MD coastal Eastern Shore (highs will struggle to get out of the 50s), while inland across VA & NC temperatures will be in the upper 80s to low 90s. While the dry weather does prevail and low RH are expected especially along and west of the I-95 corridor, winds do not look impressive. So no fire headlines have been issued during this update and fire weather concerns remain minimal.

KEY MESSAGE 2...Showers are likely Sunday, but areal average rainfall amounts continue to look minimal. Fire WX concerns return next Monday in the wake of the cold front, especially if rainfall amounts are minimal. A low pressure system is progged to track over eastern Canada Sunday. Model guidance continues to show a strong cold front associated with this system tracking through the area. Models continue on the trend of very minimal moisture ahead of the approaching front. Pops have lowered due to the lack of moisture and are now between 60-70% across much of the area, with the highest pops maximized across the tri-cities north (70-80%). The cold front looks to be mostly ana-frontal in nature (rain falling primarily behind the frontal passage). With the cold front passing through the NW 1/2 of the FA early on in the day, temperatures in the late morning to early afternoon would potentially be in the 50s for much of the FA. This could easily yield 24 hour temp changes on the order of 30 degrees F. In question of how much QPF could the area receive is still in question. The latest deterministic models continue to hint on a drier frontal passage with much of the area seeing less than .1" of rain. While the 18/00z Canadian and Euro ensembles are holding strong with 50-70% probabilities of 0.1"+ QPF. While the GFS ensemble looks to be an outlier with 30-40% probs. Nonetheless, any rainfall is welcomed as the drought conditions worsen.

A much cooler and drier airmass will move into place behind the passing cold front Sunday night/early Monday. Temps Sun night will fall into the 40s with perhaps some upper 30s in the piedmont but no frost is expected. During the day Monday models hint on a second surge of drier air as the high pressure moves out of the NW. This will allow for RH values to between 20-25% with perhaps some RH values in the upper teens. In addition, breezy conditions are progged and win gusts could be between 20-25mph. Red Flag warning may not be reached, however, an IFD for Fire WX continues to look likely for Monday.

KEY MESSAGE 3...There is the potential for patchy frost and even localized freezing temperatures for inland areas Monday night into Tuesday morning. Then temperatures begin to increase through the middle of the week.

The 18/00Z model guidance continues to remain in decent agreement with a strong high pressure (>1030mb) moving out of the NW Monday evening, the eventually moving and settling across the FA by Tuesday AM. Since the last forecast update, the timing from both the GEFS/ECMWF have come into better agreement. It looks more likely that most of the area decouples except for the SE coast. The highest confidence for patchy frost still remains the far NW where temps could drop into the low 30s. Confidence elsewhere is low due to the very high dew points and temperatures remaining in the mid 30s. The coast will be fine as lows are progged in the low 40s. By Tuesday, the high pressure will eventually move back off the SE coast and temperatures will begin to increase (though still remaining below average, especially on the coast and the eastern shore). By the middle and through the end of next week temperatures will return into the 80s with minimal chances of rain expected.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

As of 200 PM EDT Saturday...

Generally VFR/dry conditions across the region this afternoon with the lone exception being in the vicinity of SBY where there is IFR stratus. Winds are easterly (~10 knots) along the coast and S to SW (5 to 10 knots) inland. IFR stratus will drift closer to SBY throughout this afternoon, eventually reaching the airport ~20-21z and lingering into the early overnight hours. A cold front approaches from the west tonight and crosses the area Sunday morning. Clouds increase ahead of the front tonight and winds become gusty out of the SW. The approaching front and increasing SW winds should help to return SBY to VFR conditions after 03z. The front crosses the area between ~10 to 14z, with light rain showers along and behind the front. CIGs may approach MVFR and linger around MVFR into the afternoon. Winds become gusty out of the N to NW with gusts of 20-25+ knots possible.

Outlook: Showers and lower CIGs dissipate Sunday afternoon, with conditions returning Sunday night through Tuesday. Gusty NW winds are anticipated Monday afternoon. Another front may drop south across the area Wednesday into Thursday, bringing at least a low-end chance for rain showers and increasing cloud cover.

MARINE

As of 325 AM EDT Saturday...

Key Messages:

- Sub-SCA conditions are expected to prevail through today.

- Solid SCA conditions expected Sunday ahead of and behind a strong cold front with a brief period of gale force gusts immediately behind the front.

A weak backdoor cold front is encroaching from the N early this morning as high pressure over the Canadian Maritimes nudges SSW along the coast. The wind is light and locally variable. Seas are 1- 2ft nearshore and 2-3ft offshore, with ~1ft waves in the Ches. Bay. The weak backdoor cold front slides down the coast this morning allowing the wind to become E 5-10kt (~10kt off the MD coast). This boundary lifts back to the N later this aftn and evening with the wind becoming SE 10-15kt, and then S 10-15kt by the evening. Seas remain 2-3ft through this evening, with 1ft to occasionally 2ft waves in the Ches. Bay building to 2-3ft late this aftn into this evening.

A strong cold front approaches from the NW late tonight and crosses the coast Sunday morning into early Sunday aftn. A SW wind is expected to increase to 15-20kt in advance of the front and then shift to NNW behind the front. 00z/18 NAM/GFS each continue to depict sharp pressure rises of 5-7mb/3hr in the immediate wake of the cold front with 950mb wind speeds of 35-40kt. Local wind probs continue to shows a 50-70% chc of 34kt gusts, primarily for the Ches. Bay and coastal/offshore waters S of Parramore Is. However, the duration is short and generally 2hr or less. Therefore, SCAs have been issued for the frontal passage and any gale force gusts immediately behind the front can be handles with SMWs. SCAs for the Ches. Bay begin at 1AM tonight and 4AM early Sunday morning for the lower James to account for increasing S then SW flow ahead of the front and then for the NNW surge behind the front. The remainder of the marine zones (aside from the offshore waters) have SCAs beginning at 7AM and 10AM for the post-frontal NNW surge. The pressure gradient slackens quickly later Sunday aftn and evening with SCAs ending during this time. Seas build to 4-5ft in the coastal waters and 5-6ft in the offshore waters/southern coastal waters, with 3-4ft waves in the Ches. Bay.

The wind becomes W 5-15kt Sunday night, and then NW 10-15kt Monday. A secondary cold front crosses the coast later Monday aftn, with a subsequent northerly surge following for Monday night. At this time the Ches. Bay has the best potential for additional SCA flags by Monday night. High pressure passes across the region Tuesday and settles offshore by the middle of next week with sub-SCA conditions expected. 3-4ft seas early next week should subside to 2-3ft by the middle of the week, with 2-3ft waves in the Ches. Bay subsiding to 1- 2ft.

CLIMATE

While RIC may approach 90F on Saturday, no additional records are expected with the record being 95. It will be much cooler closer to the coast, and nowhere near records.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 10 PM this evening to 7 PM EDT Sunday for ANZ630>632-634. Small Craft Advisory from 10 AM to 7 PM EDT Sunday for ANZ633. Small Craft Advisory from 7 AM to 4 PM EDT Sunday for ANZ635>637. Small Craft Advisory from 4 AM to 4 PM EDT Sunday for ANZ639. Dense Fog Advisory until 4 PM EDT this afternoon for ANZ650- 652. Small Craft Advisory from 7 AM to 7 PM EDT Sunday for ANZ650- 652-654. Small Craft Advisory from 10 AM to 10 PM EDT Sunday for ANZ656- 658.