textproduct: Wakefield

WHAT HAS CHANGED

Small Craft Advisories issued for the Ches. Bay and nearshore coastal waters for tonight through Monday.

KEY MESSAGES

1)Dry and seasonably cool through the middle of the week.

2)A strong cold front brings chances for rain Thursday-Friday, though models have trended drier. Below Average temperatures follow behind the front.

DISCUSSION

As of 230 PM EST Sunday...

KEY MESSAGE 1...Dry and seasonably cool through the middle of the week.

Beautiful fall weather is ongoing and will continue for the next several days. Latest sfc analysis indicates high pressure centered over the south-central CONUS expanding eastward to cover the Southeast. It is being held back from building fully into the Mid- Atlantic by low pressure systems both north of the Great Lakes and near Nova Scotia. Aloft, A trough is in place over the Great Lakes and New England placing the local area under relatively weak NW flow. Not expecting temps to get quite so chilly tonight since the positioning of the high will allow for a light SW breeze thus limiting radiational cooling. Looking at lows in the low to mid 40s. Tomorrow, a dry cold front will push south and NW winds will become breezy during the afternoon behind it. While highs will be able to get up into the mid 60s, gusts of 15 to 25 mph will keep it feeling more like the upper 50s. Winds likely diminish in time for efficient radiational cooling Monday night leading to lows in the 30s for most places, low 40s immediately near the coast. High pressure slides east, the center of it staying to the south, Tuesday and Wednesday. Flow aloft becomes more zonal. As a result, temps become a little milder with highs around 70 both days.

KEY MESSAGE 2...A strong cold front brings chances for rain Thursday-Friday, though models have trended drier. Below Average temperatures follow behind the front.

Guidance is pretty much all on the same page in the 12z runs signaling a big pattern shift at the end of the week. Everything indicates an anomalous 500mb trough developing across the eastern half of the country Thursday into Friday. This would mean that much cooler, below average temperatures are on the way for Friday and the weekend. NBM puts highs in the low-mid 50s through Sunday, but would not be surprised to see some spots struggle to leave the 40s on Saturday. Overnight lows look to be around freezing each night away from the immediate coast. Jury is still out on how much rain we can get out of this system. Ensembles did trend a tad lower with respect to QPF. At this point it seems like even 0.5" is unlikely with the wettest of the ensembles (ECMWF Ens) only show 20-40% probs for QPF >0.5". The GEFS and GEPS barely show any probs in this category. Probs for >0.1" jump up to 40-70%. Areas north of I-64 have the best shot at appreciable rainfall Thursday evening through Friday.

AVIATION /19Z SUNDAY THROUGH FRIDAY/

As of 1235 PM EST Sunday...

VFR conditions prevail through the 18z/08 TAF period. TAFs are mostly just a wind forecast skies should stay mostly clear and no fog is expected. SW winds are generally light this afternoon with the exception of SBY where there have been wind gusts up to 20kt. Winds turn to the W, then NW overnight and tomorrow morning behind a dry cold front becoming gusty in the afternoon.

Outlook: VFR conditions are expected to continue into the middle of next week. Another cold front approaches from the W Thursday with rain possible.

MARINE

As of 230 PM EST Sunday...

Key Messages:

- Elevated winds continue through Monday with W winds today shifting to the SW tonight and then NW Monday. Small Craft Advisories go into effect tonight for the Chesapeake Bay and coastal waters through Monday evening.

- Calmer marine conditions return to the waters beyond Monday and continue through most of the upcoming week. Degraded winds and seas/waves are possible by Friday into weekend as low pressure approaches the area, but confidence in details is low.

High pressure centered over the Deep South, extending towards the Mid-Atlantic has allowed winds to relax over the local waters. W winds are currently ~10-15 kt across the Ches. Bay and coastal waters this afternoon with 2-4 ft seas and ~1 ft waves. A dry cold front will cross the area from the W this evening and tonight. Ahead of the front, SW winds will increase to ~20 kt with gusts to 25 kt across the Ches. Bay and coastal waters, peaking shortly after midnight (05z) for a ~6 hr period. The front will cross the waters after sunrise shifting winds out of the NW, but the cold air advection will lag some, resulting in a brief lull in SCA conditions Monday morning. The CAA will reach the waters by Monday afternoon with winds increasing again to 15-20 kt with gusts to 25 kt in the Ches. Bay and 20-25 kt with gusts to 30 kt on the coastal waters (highest in the N waters). Additionally, seas will increase tonight to 3-5 ft, remaining elevated through Monday evening. 6-7 ft seas are possible beyond 20 nm Monday. Waves in the bay will generally be 2-3 ft through Monday. With this, SCAs have been issued for the Ches. Bay and coastal waters beginning tonight through Monday night.

High pressure will build into the area late Monday night through mid week, allowing winds to fall below SCA criteria. Winds will be mostly SW ~10 kt on Tuesday, light and variable Wednesday, and S ~10-15 kt on Thursday. Seas also average 2-3 ft Tuesday through Thursday. By mid week, a low pressure system looks to form in the midwest, potentially approaching the region and moving up the coast. There is still much uncertainty with the track of the system, but elevated winds and seas are possible Friday into the weekend.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 7 PM this evening to 10 PM EST Monday for ANZ630. Small Craft Advisory from 7 PM this evening to 7 PM EST Monday for ANZ631-632-634. Small Craft Advisory from 10 PM this evening to 10 PM EST Monday for ANZ650-652-654. Small Craft Advisory from 10 PM this evening to 10 AM EST Monday for ANZ656-658.