textproduct: Wakefield

WHAT HAS CHANGED

- Updated Aviation for 18z TAFs - QPF continues to trend downward for Monday.

KEY MESSAGES

1) Light rain and cooler temperatures remain likely behind a cold front Monday.

2) A gradual warming trend is expected through the upcoming week. Showers with isolated storms are possible Wednesday afternoon into Wednesday night.

DISCUSSION

As of 245 PM EDT Sunday...

KEY MESSAGE 1...Light rain and cooler temperatures remain likely behind a cold front Monday.

A warm Mother's Day is underway with temps well into the 80s for most locations. Skies are generally sunny, except seeing some scattered cumulus across the far NW and in NE NC/far SE VA where dew points are a tad higher. Showers and isolated storms are expected to initiate on the higher terrain to our NW later this afternoon, along an elongated cold front that extends from New England into the MS Valley and southern Plains. Most of the activity should remain north of our CWA boundary in closer proximity to the upper forcing and sfc front, though wouldn't be surprised if a few showers spill over into the N/NW third of our area. This would be generally N and W of the Richmond metro. MUCAPE would be 250 J/kg at best, so storms are not really favored.

Anafrontal (light) rainfall develops behind the front Monday as a shortwave aloft passes through and weak low pressure develops to our S. In what seems like a very common trend this Spring, model guidance continues to adjust the expected rainfall forecast downward. Our forecast, driven primarily by the NBM, now depicts little to no measurable rainfall for southern VA and NC Monday, with perhaps a tenth or two further N into central VA, the VA Northern Neck, and the Eastern Shore. This light rain and overcast skies will keep temperatures quite chilly and likely only in the 50s and 60s for most of the daylight hours Monday. Some clearing in possible late in the day as drier air filters in, so a few locations across the N could rebound a few degrees by that time. Lows Monday night drop into the low-mid 40s inland and upper 40s-lower 50s at the coast.

KEY MESSAGE 2...A gradual warming trend is expected through the upcoming week. Showers with isolated storms are possible Wednesday afternoon into Wednesday night.

The trough axis moves offshore Tuesday as transient ridging builds over the OH Valley. At the surface, high pressure translates eastward and settles over our area during the afternoon. This will allow temperatures to rebound back into the 70s, with dry air through the column favoring sunny skies.

The high quickly shifts offshore Wednesday, occuring in advance of a stronger area of low pressure that will move through the upper Great Lakes vicinity. An associated cold front eventually pushes through the region later Wednesday into Wednesday night. Showers (and isolated storms) are likely to accompany this frontal passage, though there remains some uncertainty on the timing, coverage, and amount of precip, as well as the potential for thunderstorms. The dynamics from the deep trough should be quite impressive with ~50 kt of flow at 500 mb. However, dew points during the afternoon and evening will likely be quite low (upper 40s/lower 50s). In tandem with very meager lapse rates aloft, ML (and MU) CAPE will be low to nonexistent during the day. This will tend to hinder any robust updrafts during the day. The appreciable forcing (and cooler temps aloft) don't arrive until after sunset, so a few storms are possible early Wednesday night as the cold front moves through. All of this suggests a relatively low, but nonzero, severe wx threat, with any stronger storm likely driven by the moderate-strong wind shear. Rainfall totals from this system also look on the light side, generally up to 0.5", but could see locally higher amounts in convection. Mainly dry wx follows to end the week and start the weekend.

A few degrees warmer Wednesday ahead of the front, nearing 80 F for a good portion of the area. A tad cooler Thursday and Friday, followed by a strong warming trend next Saturday and Sunday as ensembles depict a tall ridge axis setting up along the Eastern Seaboard. Temperatures are likely to warm well into the 80s and potentially approach 90 F by this time.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

As of 130 PM EDT Sunday...

Favorable flying wx at all terminals this afternoon, with either SKC or FEW CU and light winds. A cold front is expected to drop S through the area late this evening into tonight, shifting winds to the N. Otherwise, VFR conditions are expected heading into this evening and tonight. The bulk of any rain still looks to hold off until after 12z; however, any rain should be very light and not have any significant impact on VSBY. Lowering CIGs are then expected later Monday morning. MVFR is possible at RIC near 18z, with any MVFR likely to hold off until after 18z at PHF, ORF, and ECG.

Outlook: Lingering MVFR is possible through Monday afternoon. Mainly VFR Monday night through Thursday, with a chc of showers and storms Wednesday aftn and evening.

MARINE

As of 130 PM EDT Sunday...

Key Messages:

- Sub-SCA conditions prevail through the early part of tonight.

- Small Craft Advisories remain in effect Monday for the Bay, lower James, Currituck sound, and the Ocean S of Parramore Island for a period of elevated N to NE winds. Benign marine conditions prevail this afternoon with light and variable winds due to sea/bay breezes. E-SE swell has subsided to ~3 ft nearshore, with waves of 1-2 ft on the bay. Winds shift to the E- SE at ~10 kt by this evening.

Sub-SCA conditions likely last through part of tonight, but a cold front crosses the waters later tonight-early Mon (most likely between midnight-6 AM). This will allow the winds to shift to the N- NE and increase to near 20 kt with gusts to 25 kt by 7-10 AM Monday morning as low pressure deepens while tracking east along the frontal boundary to our south. The low continues to intensify offshore Mon night as the next area of high pressure builds in from the NW Tuesday. The 12z models are in relatively good agreement showing decent SCA conditions across the lower bay, with ~50% probabilities for 25 kt gusts on the ocean south of Cape Charles. Only made minor timing changes to the SCAs (mainly to start it a few hours earlier for the bay). Headlines go into effect on the bay starting at 1 AM, expanding to the lower James and Ocean zones by 7 AM, and eventually to the Currituck sound and NC Ocean later Monday morning. Peak winds likely occur between 8 AM-4 PM (earliest N/latest S), with a drop in winds (to 5-10 kt north/15 kt south) expected by mid to late evening as the low pushes farther offshore. Still expect a secondary CAA surge Monday night-Tuesday morning, but winds with this do not appear to be as strong (~15 kt...perhaps a bit higher north). Probs for sustained 18 kt winds are generally 20- 40% on the mid/upper bay Tuesday morning. SCAs end on the bay/lower James Monday evening, but can't rule out an extension through Tue AM across the bay (mainly N of New Pt Comfort). Seas will build to 5-7 ft nearshore in NC, and 4-6 ft off the VA Capes in the N-NE flow, so SCAs on the ocean run through Mon night/early Tue. Conditions improve later Tuesday as the system moves well offshore with high pressure becoming centered over the local area. The high slides offshore Wed, with a return to southerly flow. Low-end SCAs are possible late Wednesday-Wednesday night ahead of another cold front. The flow becomes NW by Thu/Fri behind that front, with low-end SCAs possible as well.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 1 AM to 1 PM EDT Monday for ANZ630- 631. Small Craft Advisory from 1 AM to 7 PM EDT Monday for ANZ632- 634. Small Craft Advisory from 10 AM to 7 PM EDT Monday for ANZ633. Small Craft Advisory from 7 AM to 7 PM EDT Monday for ANZ639. Small Craft Advisory from 7 AM Monday to 1 AM EDT Tuesday for ANZ654-656. Small Craft Advisory from 10 AM Monday to 6 AM EDT Tuesday for ANZ658.