textproduct: Wakefield

WHAT HAS CHANGED

Updated for 00z aviation discussion.

KEY MESSAGES

1) A slight chance for showers across the far north tonight.

2) Well above normal temperatures Sunday through Wednesday. A small chance for showers/storms across central VA Sunday afternoon. Otherwise, little appreciable rainfall is expected until at least Wednesday night or later.

DISCUSSION

As of 300 PM EDT Saturday

KEY MESSAGE 1...A slight chance for showers across the far north tonight.

Latest guidance suggests that a few showers may move eastward tonight across the far north in response to a weakening short wave. The 12z CAMS suggest the best chance for this activity will stay north of the area, however there is enough support from the CAMS keep slight chance PoPs across the far north into the MD eastern shore tonight. Rainfall, if any, will not amount to much due the very dry air aloft.

KEY MESSAGE 2...Well above normal temperatures Sunday-Wednesday. A small chance for showers/storms across central VA Sunday afternoon. Otherwise, little appreciable rainfall is expected until at least Wednesday night or later.

Big story through Wednesday will be the summer-like high temperatures each day. Sunday will be the start of widespread temperatures in the 90s. Areas west of I-95 have the best chance at reaching the low 90s Sunday with the multi-model ensemble showing a 65-85% prob of 90 or greater, the coastal areas likely staying a few degrees cooler. The REFS and NBM suggest some isolated convective development Sunday afternoon over central Virginia given the MLCAPE values of nearly 1000 j/kg. However, given the building heights across the region, the atmosphere may remain capped through the afternoon. Nonetheless, the lee trough may be just enough for an isolated storm on Sunday afternoon and have maintained the slight chance PoPs from the NBM on Sunday afternoon.

Otherwise, the remainder of the week through Wednesday looks dry and hot. Ensemble guidance suggests broad support for widespread temperatures in the low to mid 90s each day through Wednesday as 850mb temps are around 18C. There is overall a very low 1-3 deg interquartile range for MaxT each day so confidence is high in these temperatures each day. Fortunately, while it will be quite hot, dew points will struggle to rise out of the low 60s each day so heat index values will not be much different than the actual temperature. In fact, the NBM essentially has a 0% probability of heat index values rising to 100 or greater next week.

The pattern turns more unsettled Thursday through the weekend. A cold front looks to cross through the region Thursday, then potentially get hung up near the coast with low pressure developing along it. At this time, the showers/storms a forecast to be most widespread Thurs afternoon through late evening. Areas south of I-64 seem to have the best chance of "higher" rainfall amounts, but the LREF prob of >0.5" of rain is still only 50-60%. Multiple rounds of precip will then be possible through the weekend.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

As of 730 PM EDT Saturday...

VFR conditions prevail for the 00z/17 TAF period. Some mid and high level clouds are moving across the region. High pressure has moved offshore with winds across the terminals mainly S or SW around 10 kt with gusts 15-20 kt. Expect winds to decrease a bit with the loss of heating this evening but should stay in the 5-10 kt range overnight. Winds inland with largely stay SW through Sunday but expect some onshore winds from sea breeze effects at ORF by the afternoon hours. Forecast soundings show some moisture around 5000 ft by the afternoon so expect FEW/SCT CU. Some instability is also noted so a shower or storm is not out of the question but confidence is far too low to mention in the TAF.

Outlook...VFR conditions expected through early next week as high pressure remains in control. South winds each afternoon may gust to 10-20kt as high pressure remains stationary off the coast. Next chance of rain not expected until late Wed or Thursday.

MARINE

As of 230 PM EDT Saturday...

Key Messages:

- Mainly Sub-SCA conditions are expected over the rivers, Currituck Sound and the Chesapeake Bay through the weekend and into early next week with primarily southerly winds.

- Building seas could result in a brief SCA over the nearshore Atlantic coastal waters tonight into early Sunday morning.

Winds have increased some this afternoon as expected with 10 to 15 kt over the Bay and 15 to 20 kt over the coastal waters. Seas have persisted around 2 to 3 ft along and off the coast even out to 60 nm, though expect some 4 to 5 ft occasional wave heights well offshore.

S/SW winds may increase a few more kt late this afternoon and early evening as suggested by some of the guidance and have accounted for this in the forecast. Winds still look generally sub-SCA criteria though some gusts to near 20 kt are possible on the Bay briefly and 25 kt on the coastal waters. Any winds to this level should be brief.

Seas offshore should peak late this evening and early Sunday morning. The easterly swell of 2 to 3 ft today will decease with mostly a wind wave of 4 ft Sunday with a 1 ft easterly swell. The highest seas overnight will be north of Cape Charles. A short- fused SCA remains in effect for this evening for the far southern coastal waters, and a slightly longer SCA was issued for tonight/overnight through early Sunday morning for nearshore coastal waters north of the VA/NC border. It is still questionable if seas will reach 5 ft, but will hold onto the SCA for now. Seas will gradually diminish Sunday morning, remaining 2-4 ft through early next week.

Sunday into early next week, high pressure settles into typical summertime Bermuda High configuration for Sunday into the middle of next week. Winds remain primarily SSW around 10 to 15 kt outside of the daily mid to late-afternoon nearshore seabreeze. The afternoon breeze will likely bring additional localized gusts of 15-20 kt to the lower Chesapeake Bay and nearshore ocean waters each afternoon before winds veer back offshore and diminish through the overnight. Expect generally benign marine conditions to prevail through midweek.

The next cold front looks to cross the waters some time early Thursday morning with increasing NE winds for the later portion of the nest week.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 10 AM EDT Sunday for ANZ650. Small Craft Advisory until 6 AM EDT Sunday for ANZ652-654-656. Small Craft Advisory until 1 AM EDT Sunday for ANZ658.