textproduct: Wakefield

WHAT HAS CHANGED

Small Craft Advisories have been issued for the Bay for this afternoon into tonight.

KEY MESSAGES

1) Mainly dry weather, slightly below average temperatures, and lower humidity to start the weekend.

2) A typical summertime pattern returns by late this weekend and early next week, with near average temperatures and increasing shower/storm chances starting Sunday and continuing through early next week.

DISCUSSION

As of 243 AM EDT Saturday...

KEY MESSAGE 1...Mainly dry weather, slightly below average temperatures, and lower humidity today ahead of an unsettled period.

Low pressure is slowly drifting off the Northeast coast, with a weak surface high across the local area this morning. Generally light southerly winds and temperatures in the upper 60s to lower 70s are being observed across the area. Satellite imagery is highlighting upper-level cirrus spreading across the East Coast that is emanating off of another low pressure system centered across Illinois. This trough will be one of the focal points for weather in the coming days, but dry conditions will continue today. Upper heights are forecast to build a bit as the ridge and aforementioned surface high nudge offshore and the low-level flow southerly flow begins to increase. Highs near 90F with afternoon dew points rising into the mid-upper 60s will make for a slightly more humid, warmer day than we have seen the past few days.

KEY MESSAGE 2....A more typical summertime pattern returns by late this weekend and early next week, with near average temperatures and increasing shower/storm chances starting Sunday and continuing through early next week.

The pattern becomes more unsettled by Sunday will continue into early next week as a slow moving upper-level trough approaches from the west. At the same time, a weak cold front approaches from the north, but will remain north of the local area through Monday (and likely wash out by Tue). With the approaching trough and Bermuda high pressure well offshore, deep-layered S to SW flow will prevail. This will allow rich Gulf moisture to overspread the area on Sunday and remain over us early next week. PWs surge from a comfortable 1- 1.4" on Saturday to 2.2-2.4" by late Sunday/Sunday night. Scattered to potentially numerous showers/tstms are expected Sunday. The highest precip chances will initially be across south-central VA during the afternoon (as the deep moisture arrives here first). Showers and tstms should gradually spread NE through the evening (though it may very well remain dry near the immediate coast and on the eastern shore). Showers/tstms are likely across the entire area on Monday as a lead shortwave potentially tracks over the area. Monday appears to be the day with the highest convective coverage during the period. The trough dampens a bit from Tuesday/Wednesday, but scattered showers and tstms are still expected during the aftn/evening on both days as weak SW flow aloft continues and deep moisture remains nearby. Given the environment and relatively weak unidirectional flow aloft and tall/skinny CAPE, there will be a threat of localized flash flooding each day, but the severe threat should remain relatively low with these storms. Temperatures dip down slightly below average during the early week period thanks to the cloud cover and multiple rounds of rain. Though not quite as unsettled as the first half of the week, the latter half of the week will see isolated to scattered afternoon showers and thunderstorms. With the decreased coverage forecast, temperatures will return to near to slightly above normal with highs in the upper 80s to lower 90s.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

As of 150 AM EDT Saturday...

VFR conditions prevail across all terminals this morning. Light, generally SE-S winds of~5 kts or less are being measured, with increasing upper cirrus moving across the area. Upper cirrus will remain across the remain across the area through this evening, with some FEW-SCT lower level clouds developing later this morning. SE-S winds will continue, but are forecast to increase to 6-10 kts.

Outlook: VFR/dry Saturday night through Sunday morning as high pressure settles offshore. Shower/tstm chances return on Sunday and Monday as a slow moving upper trough approaches the area, and linger into Tuesday/Wednesday. Periodic sub-VFR conditions are possible during this time, mainly from early morning stratus, and brief vsby restrictions in heavy rain.

MARINE

As of 220 AM EDT Saturday...

Key Messages:

- Small Craft Advisories have been issued for the Chesapeake Bay from this afternoon into the early overnight hours.

- Another period of SCA conditions is likely Sunday afternoon into Monday ahead of a weakening cold front.

Early morning analysis shows high pressure off the Southeast coast with surface low pressure and cold front noted over the Midwest. Winds over the local waters are generally from the S at 5-10 kt. Waves in the bay are around 1 ft with seas 2 ft. The aforementioned Midwest low will become vertically aligned with an upper closed low today, resulting in only slow movement to the east. Guidance suggests that the gradient between this low and high pressure offshore will tighten sufficiently to result in 15-20 kt SW winds over the Ches Bay from this afternoon through the evening hours. Winds in the tidal rivers, Currituck Sound, and offshore zones are expected to stay below SCA thresholds. Winds are expected to relax back into the 10-15 kt range after midnight. Waves and seas briefly build to 2-3 ft during the enhanced SW flow tonight. The surface low and its associated cold front will translate slowly eastward on Sunday, allowing the pressure gradient to steepen again. Additional SCA headlines are likely Sunday night into Monday for the majority of the local waters. Given a longer duration SW flow event, seas will have more time to build into the 3-6 ft range (0-20nm range, highest N). Farther offshore, seas increase to 5-7 ft for a period late Sunday into Monday. The front is forecast to wash out over inland areas late Monday into Tuesday.

Afternoon and evening shower and storm chances return Sunday and linger well into next week with locally higher winds/waves/seas likely to accompany the stronger convection.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 4 PM this afternoon to 1 AM EDT Sunday for ANZ630>632-634.