textproduct: Wakefield

WHAT HAS CHANGED

18z Aviation discussion. Probabilities for snow and freezing rain continue to decrease for the early week system.

KEY MESSAGES

1) Remaining mild this weekend. Areas of fog developing along the coast late this evening. However, temperatures are likely to abruptly fall into the 40s and 50s Sunday afternoon along the coast of eastern Virginia and the Lower Eastern Shore.

2) Minor impacts are possible from light snow and sleet or freezing rain Monday night into Tuesday morning, but probabilities for any accumulation continue to trend down.

3) A significant warming trend is possible by the middle and end of next week.

DISCUSSION

As of 250 PM EST Saturday...

KEY MESSAGE 1...Remaining mild this weekend. Areas of fog developing along the coast late this evening. However, temperatures are likely to abruptly fall into the 40s and 50s Sunday afternoon along the coast of eastern Virginia and the Lower Eastern Shore.

Latest analysis reveals a coastal trough lingering offshore of the Carolina coast early this afternoon, with marine stratus draped along the immediate coast and offshore. Farther inland, stratus that lingered over the piedmont for much of the morning into the early afternoon has eroded, leaving a mainly clear/sunny sky across the region on very light winds. Remaining mainly clear into late this evening. Still a decent signal for areas of marine stratus/dense fog to recur along the eastern shore and VA/NE NC coastal plain.

Sunday will begin with light southwest flow ahead and another chance for above normal temperatures ahead of an approaching backdoor cold front. Still looking like the front drops across the region through Sunday afternoon, leading to abruptly falling temperatures and a large northeast-southwest gradient in high temps across our CWA. Regardless of the timing of the front, well above temperatures are forecast for most of the area, albeit briefly for northern areas. Behind the backdoor cold front, temps abruptly drop into the 40s & 50s Sunday afternoon along the coast, and for the rest of the area Sunday night. This will be quite the shock in the wake of this weekend's spring-like highs. Cooler overnight Sunday with lows in the upper 20s to lower 30s.

There has also been an increasing signal for a few light showers Sunday evening. 12z/28 CAMS (mainly RRFS/time-lagged HRRR/HREF) have shown some semblance of scattered showers developing along the front, as it drops across south central and southeast VA late tomorrow afternoon into early Sunday evening. Accordingly, while sub-cloud layer remains rather dry, did add a 20% PoP for a few isolated showers mainly south of I-64 tomorrow afternoon.

KEY MESSAGE 2...Minor impacts are possible from light snow and sleet or freezing rain Monday night into Tuesday morning, but probabilities for any accumulation continue to trend down.

A more unsettled pattern will start next week off, with additional chances for precipitation. High pressure across the Great Lakes region on Sunday will gradually slide eastwards over the Northeast and wedge down across the Mid- Atlantic. This is typically a favorable location for a high in regards to possible winter weather, but the depth of the cold air and how quickly the high shifts offshore will be very important in determining the precip type as a series of shortwaves move through aloft Monday into early Tuesday. Snow or even sleet and freezing rain are possible over portions of the area depending on the depth of the cold air late Monday into early Tuesday. The past few model suites, including the latest 12z/28 suite have depicted the high to our north becoming increasingly progressive with time. Thus, the colder air does not stay in place long across the area, and probabilities for both ice and snow accumulation continue to drop with the 12z guidance. Due to these lowering probabilities and very marginal thermal profile during this time frame, minimal snow remains in the forecast at this point for Monday afternoon and early evening, and have capped PoPs at ~20-30%. With that being said, probabilities for light freezing rain/ice accretion have come up a bit over the VA Piedmont counties along US-15. Some very light overrunning moisture could well be present Mon night into Tue morning, and some spotty light freezing rain or freezing drizzle could create some slick spots, especially on untreated and elevated surfaces for the Tuesday morning commute. We will continue to monitor this system for any changes in amounts/evolution/timing and adjust the forecast as necessary.

KEY MESSAGE 3...A significant warming trend is possible by the middle and end of next week.

The good news is that after the cooler start to the week, some warmer weather is on they way. Ensemble guidance continues to depicting a large, anomalous upper level ridge building over the eastern U.S, w/850 mb temperature anomalies building well above average. If this set-up comes to fruition, temperatures will rise to well above normal, with highs potentially reaching the lower to mid 70s by late next week and lows only in the upper 40s to near 50F. By next weekend, some guidance is edging very close to the 80F mark for inland areas. While there is good agreement on the overall synoptic pattern, there is always a chance that the colder airmass associated with the backdoor cold front over-stays its welcome and keeps temperatures cooler than forecast. Have continued to maintain well above normal temperatures late week and into the weekend, as there is not much support at this time for a lingering cooler airmass. A series of weak fronts bring low-end chances for showers toward the end of next week as well, but widespread rainfall is not expected.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

As of 549 PM EST Saturday...

Generally VFR conditions are being observed at all terminals early this evening. Guidance is continuing too hint at additional marine stratus and fog development tonight, and have included some IFR/LIFR CIGs developing tonight at KECG. At remaining coastal terminals, did include some low-end MVFR CIGs/VSBY at SBY/PHF, but confidence was not quite high enough to include at ORF this time. Winds will remain light from the N/NE, becoming variable at times, through the TAF period. MVFR/IFR CIGs appear more likely by later Sun aftn and Sun night across terminals, as a cold front drops into the region.

Outlook: High pressure builds down into the region Sunday night into Monday as several disturbances pass through. These are likely to bring additional periods of light precip for the beginning of next week and potential flight restrictions. A brief period of wintry precipitation is possible at RIC/SBY Monday night into Tuesday.

MARINE

As of 250 PM EST Saturday...

Key Messages:

- Sub-SCA conditions with relatively light flow from high pressure over the area through Sunday morning.

- SCAs have been issued for the Chesapeake Bay, coastal waters, lower James River and Currituck Sound as a backdoor cold front from strong high pressure to the NE crosses the waters Sunday afternoon.

Latest wx analysis shows high pressure over the area this afternoon with a lingering upper trough, with subsequent surface stationary front, offshore to the SE. The high pressure over the area allows for relatively light N/NE winds around 5-10 kt. Waves and seas are currently ~1 ft in the Ches. Bay and 2-3 ft in the coastal waters. Winds will become S/SW tonight still around 5-10 kt ahead of the next cold front approaching from the N. Marine fog/ low stratus clouds could develop overnight across the coastal waters and Ches. Bay as dewpoints reach near water temps (mid to upper 30s) with light winds. Will continue to monitor trends and cameras for the possibility of needing Marine Dense Fog Advisories.

Beginning Sunday afternoon for the middle Ches. Bay and northern coastal waters, the backdoor cold front drops across the local waters. Models continue to show a strong (~1040 mb), progressive high pressure to the north of the area pushing CAA over the waters, as well as fairly strong pressure rises, Sunday afternoon into Monday morning. Latest CAM models trends the cold front moving through the area slightly fast, now with backdoor front crossing the middle Ches. Bay and northern coastal waters Sunday afternoon, and crossing the NC coastal waters Sunday evening. Elevated N/NE winds around 15-20 kt and gusts to 25 kt are expected through Monday morning. An initial burst with the front could have gusts up to 30 kt. The upper rivers are more marginal, due to the wind direction. Seas will increase to 4-5 ft N and 5-7 ft S, and waves to 3-4 ft, peaking late Sunday into early Monday morning. With this, Small Craft Advisories have been issued for the Chesapeake Bay, coastal waters, lower James River and Currituck Sound, with staggering start times from N to S beginning Sunday afternoon. 5 ft seas will likely linger into Monday afternoon in the southern waters. Then, benign marine conditions return for the week.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 1 PM Sunday to 10 AM EST Monday for ANZ630-631. Small Craft Advisory from 4 PM Sunday to 1 PM EST Monday for ANZ632>634-638-650-652-654. Small Craft Advisory from 7 PM Sunday to 7 PM EST Monday for ANZ656-658.