textproduct: Wakefield

WHAT HAS CHANGED

Updated aviation section for 00z TAFs.

KEY MESSAGES

1) Scattered showers (and a few storms) continue this afternoon, especially east of I-95 and north of I-64 as a backdoor cold front moves slowly to the west and southwest.

2) Rain chances increase late Saturday into Saturday night as a cold front and wave of low pressure move into the region. Showers linger along the coast Sunday, along with cooler conditions for the entire area. Dry weather returns to the area Monday.

3) There are several opportunities for rainfall next week as an unsettled pattern potentially develops.

DISCUSSION

As of 255 PM EDT Friday...

KEY MESSAGE 1...Scattered showers (and a few storms) continue this afternoon, especially east of I-95 and north of I-64 as a backdoor cold front moves slowly to the west and southwest.

Afternoon analysis shows a backdoor front over the Eastern Shore making S and SW progress. Ahead of this boundary, widely scattered showers and a few storms have developed. Forecast soundings show increasingly dry low levels with westward extent, so expect the relative highest convective coverage to be mainly east of I-95 and along and north of I-64. Given the degree of low level dry air, any shower or storm has the potential to produce locally gusty winds and perhaps even some small hail. Not expecting either winds or hail to approach anything close to severe thresholds today. Temperatures are mainly in the 80s ahead of the front with some 70s along the Ches Bay and inland portions of the Eastern Shore. Temps along the immediate coast near Wallops and Ocean City have fallen into the 60s. Showers come to an end this evening with lows overnight in the 50s.

KEY MESSAGE 2...Rain chances increase late Saturday into Saturday night as a cold front and wave of low pressure move into the region. Showers linger along the coast Sunday, along with cooler conditions for the entire area. Dry weather returns to the area Monday.

Dry conditions are likely for the area through Saturday morning. Rain chances increase substantially later in the afternoon as low pressure tracks along an approaching cold front. A few storms are also possible in the vicinity of the low and front. Latest guidance shows some meager/thin instability and veering winds with height across the SE quarter of the area but no widespread strong to severe storms are expected. Temperatures are expected to vary widely across the local area with warmer readings expected S and SW with cooler temps for NE portions of the area.

The trend toward a slower progression and stronger surface low have continued in the guidance today. The bulk of the precip is expected after sunset Saturday through the overnight. Higher PoPs are favored east of 95 and near the coast during the daylight hours of Sunday. Temps have trended substantially downward on Sunday with widespread clouds/showers and NE winds. Highs range from the mid 50s N to the mid and upper 60s S. 12z ensemble guidance is split with respect to QPF across the region. The 12z EPS has actually trended downward for probs of 0.5" or more while the 12z GEFS has trended upward (rather significantly to 50-80% chances, mainly for central and eastern portions of the area). The last several runs of the operational ECMWF have shown a weaker low off the Delmarva and a stronger secondary low off the NC coast later on Sunday. Any convective enhancement to QPF would also favor higher totals and this aligns well with the now ~10-30% probs for 1". Aerial QPF from our forecast depicts 0.5-1" for the entire area. Still, this is far from a drought-buster given the substantial rainfall deficits across our area.

KEY MESSAGE 3...There are several opportunities for rainfall next week as an unsettled pattern potentially develops.

Troughing may develop over most of the CONUS by the middle the later half of next week, with several fronts and disturbances potentially passing through the region. The latest CPC outlook favors slightly above average rainfall in the 6-10 day period. 12z operational and ensemble guidance shows another round of mainly light precip on Tuesday with a potentially more substantial slug of moisture expected late Wednesday. Specifics beyond this time are uncertain but chance PoPs are in place through most of the week. Temperatures generally hover around average for mid-late Spring with variable cloudiness.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

As of 755 PM EDT Friday...

Primarily VFR conditions to start off the forecast period with widely scattered showers (isolated thunderstorms) mainly in the vicinity of RIC and SBY. Showers should gradually diminish over the next few hours with the loss of daytime heating. Otherwise, VFR conditions are expected to prevail through the night. MVFR CIGs develop by mid to late morning Saturday at SBY along a backdoor cold front. MVFR CIGs then linger at SBY throughout the remainder of the forecast period. Low pressure approaches from the west Saturday afternoon, bringing a chance for showers or thunderstorms later Saturday afternoon and evening. Winds average E to ESE ~10 knots through a majority of the forecast period.

Outlook: MVFR to IFR CIGs develop at all sites Saturday night into Sunday. High pressure builds to the N Sunday with an onshore component to the wind persisting along the coast, which could result in persistent lower CIGs. VFR and dry conditions return by Monday.

MARINE

As of 140 PM EDT Friday...

Key Messages:

- Mainly sub-SCA conditions are expected to prevail through tonight, with Small Craft Advisory conditions expected across the northern coastal waters on Saturday as easterly winds increase to around 20 kt.

- Solid SCA conditions expected Saturday night through Monday as low pressure deepens offshore. Gusts to Gale Force will be possible over the coastal waters Sunday into Sunday night. Gale Watches have been issued for all coastal waters north of the VA-NC border from Sunday morning through Sunday evening/Sunday night.

A backdoor cold front is crossing the waters this afternoon, with E- NE winds of 10-15 kt over most of the waters (and lighter winds south). Winds increase out of the E to near 10-15 kt by this evening with gusts to 20 kt. The main concern through this evening is the chance for isolated showers/tstms. While severe weather is unlikely, the strongest storms could produce gusts of ~40 kt over the marine area, necessitating SMWs. The threat for storms quickly diminishes after sunset, with E-ESE winds around 15 kt with gusts to 20 kt expected for most of the night.

Low pressure begins developing along the front Saturday, with E winds increasing to ~20 kt with gusts to 25 kt over the coastal waters N of Cape Charles during the day. The highest winds will be over the MD coastal waters. Sub-SCA SE winds are expected over the southern coastal waters on Sat. The low pressure system deepens as it pushes offshore late Saturday night and especially Sunday. This will allow the front to move to the SE of the local waters. With the increasing pressure gradient behind the front, N-NE winds are expected to increase to 20-25 kt with gusts to 30 kt by mid morning on Sun, with a period of 25-30 kt winds possible over the coastal waters (w/ gusts to 35-40 kt) from late Sunday morning through the first part of Sunday night. Occasional gale force gusts are possible on the bay (especially near the mouth of the bay) during this time. Local wind probabilities for Gale Force Gusts (34 kt+) are roughly 50-70% across the waters N of the VA-NC border. As such, have issued Gale Watches for all ocean zones out to 60nm from Sunday morning- late Sunday evening for these zones (not including NE NC). Have also issued a ramp up SCA starting Saturday for the northern two nearshore coastal zones. Winds diminish a few knots Sun night-Mon as the low pulls farther offshore, but solid SCA conditions with N-NE winds appear likely through Monday for all waters. Sub-SCA winds finally return on Tuesday.

Seas build to 3-4 ft S/5-6 ft N on Saturday, before building to 8-14 ft (highest 60nm offshore) by late Sunday. Waves on the bay gradually build to 3-6 ft (highest at the mouth) by late Sunday. Seas slowly diminish early next week, but 5 ft seas could persist nearshore through Tue/Tue night.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 10 AM Saturday to 7 AM EDT Sunday for ANZ650-652. Gale Watch from Sunday morning through Sunday evening for ANZ650-652-680-682. Gale Watch from Sunday morning through late Sunday night for ANZ654-656. Gale Watch from Sunday morning through late Sunday night for ANZ684-686.