Area Forecast Discussion

WHAT HAS CHANGED

QPF continues to trend downward for most of the area today with much of the rainfall focused across far southeastern VA and northeastern NC.

KEY MESSAGES

1) Weak low pressure moves off the Carolina coast today and slowly deepens well offshore this evening. Precip chances continue to diminish inland with max QPF below 0.5", even where PoPs are highest in far SE VA and NE NC.

2) Cool Sunday with a warming trend Monday and Tuesday. Another front brings the chance for precip back to the area mid to late week.

DISCUSSION

As of 250 AM EDT Saturday...

KEY MESSAGE 1...Weak low pressure moves off the Carolina coast today and slowly deepens well offshore this evening. Precip chances continue to diminish inland with max QPF below 0.5", even where PoPs are highest in far SE VA and NE NC.

Broad low pressure has started to develop off the Carolina coast early this morning ahead of a southern stream disturbance. Latest guidance continues the trend of decreased QPF with most areas away from Hampton Roads/southern VA coast and NE NC not likely to see more than a few hundredths of rainfall out of this system. QPF continues to decrease even for these areas with storm total rainfall likely below 0.5". Farther inland, the main impact from this system will only be thicker cloud cover and cooler temps. The relative warmest high temps today will be over central and NW portions of the area with little to no rainfall and temps in the low 60s. Upper 50s are forecast in areas that actually see some precip and evaporational cooling through the afternoon. Low pressure deepens well offshore this evening with winds turning NW. Some cold advection will move in behind the departing low but winds are not expected to fully decouple overnight, resulting in temps in the upper 30s NW to the low/mid 40s toward the coast. If winds are less than currently forecast, a few of the cooler/outlying rural spots in the Piedmont could dip into the mid 30s with potential for patchy frost prior to sunrise. Some of the statistical guidance shows this possibility.

KEY MESSAGE 2....Cool Sunday with a warming trend Monday and Tuesday. Another front brings the chance for precip back to the area mid to late week.

Clearing skies with continued cool temperatures expected Sunday. Highs will mainly be in the mid 60s with breezy NW winds, especially for N and NE portions of the area. Falling dew points and lack of rainfall may result in some fire weather concerns Sunday afternoon, as RH is forecast to fall to 25-30% away from the immediate coast. Winds are forecast to decrease through the afternoon as the pressure gradient relaxes, however. Flow turns SW on Monday with temps moderating back into the mid and upper 70s as high pressure translates offshore. Warmer and dry Tuesday with highs in the low 80s. Another weak disturbance brushes the northwestern half of the area Wednesday with mainly slight chance PoPs. Deeper moisture potentially moves into the region Wednesday night and especially Thursday ahead of the next front. The latest guidance now focuses the higher PoPs during the day Thursday into early Friday. Temperatures trend near or slightly below seasonal averages later in the week.

AVIATION /09Z SATURDAY THROUGH WEDNESDAY/

As of 550 AM EDT Saturday...

VFR conditions prevail for most of the area with some MVFR CIGs starting to impinge on portions of NE NC, including ECG. Deeper moisture moves northward after sunrise with prevailing MVFR CIGs likely at ECG after 14z. Rainfall is not expected to be particularly heavy so have limited VSBY to 4-6SM at ECG. Latest guidance keeps VFR at the remaining terminals. Will have prevailing -RA at ORF and PHF but not expecting much in the way of flight restrictions. N and NNE winds 5-10 kt at RIC, SBY and PHF. ORF and ECG will average 10-15 kt with gusts up to 20 kt through the day. All precip should exit the area before 00z tonight.

Outlook: Drying out Sunday with mainly VFR conditions through early next week.

MARINE

As of 250 AM EDT Saturday...

Key Messages:

- Low pressure intensifies off the NC OBX this afternoon into tonight. Small Craft Advisories have been issued for all local waters south of Chincoteague.

- Small Craft Advisories are possible for the Chesapeake Bay late Monday night into early Tuesday due to increasing southerly winds. There is a more widespread SCA potential beginning later Tuesday and potentially lasting through much of the mid to late week period.

Early this morning, developing ~1010 mb low pressure is situated off the SC coast. Meanwhile, weak high pressure is located just to our northeast. Winds remain fairly light (5 to 10 knots) out of the S to SW. Seas are running around 3 to 4 feet, and waves in the Chesapeake Bay 1 to 2 feet. The low off the SC coast will continue to intensify as it moves northeast later today into tonight. Winds become N to NW later this morning and the gradient will gradually tighten. Winds increase to SCA levels later this morning into this afternoon, with the strongest winds (gusts ~25 to 30 knots) expected over the southern coastal waters. Conditions will be a bit more marginal across the Chesapeake Bay (especially the northern zones), but gusts to 20 knots are still possible. A better N to NW surge of wind is expected tonight into early Sunday morning, with widespread gusts of 25 to 30 knots likely for all areas minus the far northern coastal waters. The current SCA was expanded to include up to Chincoteague for the overnight timeframe. In addition to increasing winds, seas will also build to 4 to 6 feet (highest across the offshore waters).

Winds and seas will diminish as we head into Sunday afternoon and remain sub-SCA through Monday. Another round of SCA is possible Monday night, mostly for the Chesapeake Bay, as southerly winds increase. Latest wind probs show ~50-70% chances for SCA conditions during the Monday night/early Tuesday timeframe. A more widespread SCA potential is likely beginning Tuesday night and potentially continuing into the mid to late week period. Winds start out southerly through much of Thursday, before becoming NW later Thursday into Friday.

AKQ WATCHES / WARNINGS / ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 10 AM EDT Sunday for ANZ630>632-634. Small Craft Advisory from 10 AM this morning to 10 AM EDT Sunday for ANZ633. Small Craft Advisory from 4 PM this afternoon to 10 AM EDT Sunday for ANZ635>637-639. Small Craft Advisory from 1 AM to 1 PM EDT Sunday for ANZ652- 654. Small Craft Advisory from 10 AM this morning to 1 PM EDT Sunday for ANZ656-658.