textproduct: Wakefield

WHAT HAS CHANGED

No significant changes.

KEY MESSAGES

1) Hot and humid conditions expected this week peaking with heat indices near 105 Wed and Thurs. Isolated storms possible, but mostly dry until late this week.

2) Shower/storm chances increase late week as a cold front approaches. Seasonable temps forecast behind the front.

DISCUSSION

As of 240 AM EDT Tuesday...

KEY MESSAGE 1...Hot and humid conditions expected this week peaking with heat indices near 105 Wed and Thurs. Isolated storms possible, but mostly dry until late this week.

The late summer heat wave is on track; temperatures in the upper 90s to around 100 are still expected over the next several days. A strong UL ridge continues to build over the gulf and up to the Great Lakes. This ridge will then translate east through the end of the week, allowing temperatures to increase more. Highs will be in the mid 90s west of the bay and low 90s on the Eastern Shore. Heat indices will climb into the 100-103F range this afternoon. Highs tomorrow will be in the upper 90s for most and even touching 100 in the southwest. A weak backdoor cold front pushing into the NE complicates the temperature forecast for the Eastern Shore and perhaps the Northern Neck. Onshore flow during the afternoon could keep temps a bit cooler by comparison with highs around 90. Widespread heat indices around 105F west of the bay Wed are forecast. Heat Advisories appear likely. Similar conditions are expected for Thurs with advisories once again likely. The heat potentially continues Friday, depending on the timing of a cold front. Highest confidence in advisory conditions is therefore across southern counties.

Regarding thunderstorm chances, isolated convection is expected both today and tomorrow. The 00z CAMs as a whole are not all that excited about either day, but kept in the slight chance in the NE today and for most of the area tomorrow. Some of the CAMs and global models to indicate some stronger convection, perhaps in the form of linear segments, to the north of the local FA. It is not outside the realm of possibility that those storms dive south into the local area. Northwest flow aloft and strong instability means that any storms that do form will have the potential for strong winds and large hail. SPC has maintained the Marginal Risk for NE portions of the area today and tomorrow. Tomorrow's slight risk does clip the MD Eastern Shore, but this would be highly dependent on the aforementioned stronger storms to the north diving south.

KEY MESSAGE 2...Shower/storm chances increase late week as a cold front approaches. Seasonable temps forecast behind the front.

The strong ridge aloft starts to break down/flatten late in the week. Meanwhile, a sfc cold front will approach and pass through the area sometime Friday- likely late. Storms will be possible ahead of it Thurs evening. Chances continue Friday afternoon as the front pushes south. NW flow will remain place aloft and progressively strengthen as the associated trough drops southward along the NE/Mid- Atlantic coast. The combination of instability and this increasing flow (and shear) suggests any storms could be strong-severe. SPC has outlooked areas N of the NC/VA border in a severe risk for Thursday and Friday.

We should see a little bit of relief from the heat over the weekend, but still seasonably warm with highs in the low 80s. Storm chances decrease as strong high pressure builds in from the north.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

As of 640 AM EDT Tuesday...

VFR conditions prevail for the 12z/01 TAF period. There is a chance of isolated evening storms. Decided to keep mention of precip out of the TAFs since coverage will likely be low and therefore confidence in terminal impacts is low. SBY would be most likely to have showers/storms, and latest models indicate later timing (after 00z). Winds will generally be light and out of the WSW, but did add a group for afternoon sea- breeze at ORF.

Outlook: Predominately dry/VFR conditions through Wednesday. Shower and storm chances begin to increase Thursday afternoon/evening (and especially Friday) at all terminals ahead of the next cold front.

MARINE

As of 205 AM EDT Tuesday...

Key Message:

-High pressure remains centered offshore through much of the week leading to sub-Small Craft Advisory conditions. A cold front approaches the waters late in the week and may bring elevated winds.

Early this morning, high pressure is centered offshore and inland, maintaining benign marine conditions across all waters. Winds are generally out of the S-SW, averaging ~10 knots. Seas are running around 2 and waves in the Chesapeake Bay around 1 foot. Similar wind speeds and directions are anticipated through much of this afternoon into the early evening.

By this evening, a cold front buckles SW, eventually approaching the far NE waters early Wednesday morning. S-SW winds increase ahead of the front to 10 to 15 knots (highest coastal waters), but should still remain sub-SCA. In addition, scattered thunderstorms (potentially severe) may impact the northern waters this evening into the first part of the night as the front drops south. The front drops south to roughly the VA/NC border through the day Wednesday before lifting back to the north as a warm front Wednesday night into Thursday. In the wake of the front, winds turn around to the N- NE ~10 knots. A cold front will approach the region Thursday into Friday with strengthening flow ahead of and (especially) behind the boundary this weekend. This could bring elevated winds and the next potential SCA conditions. Shower and storm chances will ramp up during the late week period ahead of the front.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...None. NC...None. VA...None. MARINE...None.