textproduct: Wakefield

WHAT HAS CHANGED

No major changes have been made to the forecast.

KEY MESSAGES

1) Widespread moderate to locally heavy rainfall is expected today, with a few thunderstorms possible.

2) Drying out and becoming seasonably cool this weekend into early next week.

DISCUSSION

As of 325 AM EST Friday...

KEY MESSAGE 1...Widespread moderate to locally heavy rainfall is expected today, with a few thunderstorms possible.

GOES water vapor channels depict a potent upper low centered over the Great Lakes with the trailing axis back into the Central Plains. Shortwave energy is evident from WV into PA. There is essentially a series of cold fronts associated with the upper trough, with the leading boundary in vicinity of the Blue Ridge early this morning. A line of showers/tstms has developed across central VA well in advance of the shortwave and ahead of the initial cold front where there is a plume of 1000+ J/kg of MUCAPE. This line of showers/tstms is quickly tracking to the NE. Brief heavy rain and occasional cloud to ground lightning are the main hazards. Otherwise, mostly cloudy and quite mild for early November with temperatures in the mid 60s to around 70F.

The initial cold front will be slow to push E through midday, before moving E toward the coast later this afternoon and evening as the parent upper low pushes SE. The airmass ahead of the trough and leading cold front is very moist for early November with PW values of 200-250% of normal. Forcing for ascent will increase along the boundary as it pushes E this afternoon with moderate to locally heavy rain possible toward the coast, with the best signal from NE NC into Hampton Roads. The 06/00z REFS generally depicts QPF of 0.5- 1.0" from the Piedmont through the RIC metro, increasing to 1.0-1.5" for the Eastern Shore, and 1.5-2.5" from NE NC into Hampton Roads with higher amounts possible. Additionally, the REFS has a contour of a 30% chc of 3"/3hr from NE NC to Hampton Roads from 18-21z this afternoon, with some moderate rain potentially lingering into the evening. WPC has maintained a Marginal ERO for the eastern half of the area. The greatest flood threat will be in urban locations as the flood threat will be limited in rural areas due to ongoing drought and low streamflow. A similar portion of the CWA is covered by a Marginal Severe Risk, mainly for 5% wind, with a 2% tornado threat in SE VA and NE NC. Bulk- Shear will generally remain between 35-45kt with MUCAPE waning through the day but remaining 500-750J/kg in SE portions of the area, and locally up to 1000J/kg in interior NE NC. These ingredients together could allow for a brief strong wind gusts with any stronger tstm embedded within the broader line of showers. There is also a very small tornado threat due to the weak 0-1 SRH (~100m^2/s^2), however, confidence remains low at this time, especially given that low-level lapse rates look rather poor in forecast soundings.

KEY MESSAGE 2...Drying out and becoming seasonably cool this weekend into early next week.

The closed upper low will drop to the WSW from the Eastern Great Lake into the northern Mid-Atlantic/southern New England region on Saturday, reinforcing northwesterly flow locally. Much cooler and drier air is forecasted to advect into the area, with high temperatures settling back to seasonal averages. High temperatures this weekend are expected to be in the lower to mid 60s and into the mid to upper 60s by early next week, and potentially reaching ~70F Tuesday. Breezy Saturday as wind gusts will be around 20-25mph out of the NW. Overnight/early morning lows drop into the mid/upper 40s W and N early Saturday morning, with mid 50s SE. Lows will then generally be in the mid 30s to lower 40s later this weekend into early next week. The recent ensemble guidance is continuing to show dry weather persisting into the middle of next week as opposed to bringing in any more rain chances.

AVIATION /08Z FRIDAY THROUGH TUESDAY/

As of 100 AM EST Friday...

High pressure was centered offshore as of 06z, with an upper level trough and cold front approaching from the W. VFR conditions prevailed under mid and high clouds, with a cluster of showers/tstms W of RIC and tracking SW-NE. Primarily VFR conditions are expected at RIC, PHF, and SBY prior to 10-12z when MVFR cigs are expected to develop. Meanwhile, MVFR cigs are expected to arrive at ORF around midday, and later aftn at ECG. A band of rain and a few embedded tstms is expected to track across the region through the day and into the evening, arriving at RIC after 10-11z (isolated-scattered showers prior to 10z), 14-16z at SBY and PHF, and more into early aftn for ORF and late aftn for ECG. Periods of IFR vsby are possible in heavier rain. A period of IFR cigs is possible at RIC 12-16z, with potential IFR/LIFR cigs at PHF, ORF, and ECG late aftn into the evening. Conditions are expected to improve after 06z tonight. A SSW wind of 8-12kt is expected prior to the frontal passage, and then shifting to N/NNE 5-10kt behind the front.

Outlook: VFR conditions anticipated through the weekend into early next week. Some NW breezes are likely Saturday afternoon and Sunday, especially across the Eastern Shore.

MARINE

As of 325 AM EST Friday...

Key Messages:

- Small Craft Advisories remain in effect through this morning for the northern coastal waters due to gusty SSW winds and 3-5 ft seas.

- Additional Small Craft Advisories have been issued tonight into Saturday morning as northerly winds increase behind a cold front passage. Another period of SCA conditions is possible Saturday night into Sunday morning.

Early morning surface analysis places an area of high pressure well offshore, with a cold front slowly advancing eastward through central VA. A tightened pressure gradient continues to lead to elevated southerly winds as of 3 AM, occasionally gusting up to 25 kt north of Cape Charles on the ocean. Winds and wind gusts are a bit lower in the Chesapeake Bay; however, occasional gusts to 20 kt are possible through the morning hours. Winds likely remain in the 15-20 kt range on the coastal waters through the early afternoon. Elevated seas, in the 3-5 ft range, are also expected through the first half of the day and Small Craft Advisories remain in effect through 12z/7 AM between Cape Charles and Parramore Island and have been extended through 18z/1 PM north of Parramore Island. Waves in the bay generally average ~2 ft, except closer to 3 ft at the mouth of the bay.

The cold front moves through this evening and winds shift to the N- NW. However, the cold advection is likely to be a bit delayed and the resultant increase in winds will also be delayed until late tonight. Still, expect solid Small Craft Advisory conditions for most of the marine area and have raised additional SCAs tonight into Saturday morning (note that SCAs N of Cape Charles are likely to be raised once the ongoing headlines this morning expire). Northerly winds are forecast to peak in the 20-25 kt range with a few gusts approaching 30 kt possible. Winds are likely to be more marginal on the rivers and have held off on any headlines here, though the lower James may need to be added to SCA eventually. Seas increase to 3-5 ft (6 ft 40+ nm offshore) with 2-4 ft waves in the bay. Winds turn to the NW/WNW Saturday afternoon and decrease to around 15 kt as an area of high pressure nudges into the area from the west. This reprieve will be short-lived as a reinforcing push of cooler air brings another increase in winds overnight Saturday into Sunday morning. Additional SCAs are probable. W-NW 10-15 kt winds prevail Sunday and Monday.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 1 AM to 1 PM EST Saturday for ANZ630- 631. Small Craft Advisory from 3 AM to 1 PM EST Saturday for ANZ632- 634. Small Craft Advisory from 6 AM to 1 PM EST Saturday for ANZ633. Small Craft Advisory until 1 PM EST this afternoon for ANZ650- 652. Small Craft Advisory until 7 AM EST this morning for ANZ654. Small Craft Advisory from 3 AM to 4 PM EST Saturday for ANZ656- 658.