textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 00z TAF issuance.

KEY MESSAGES

- 1. Generally dry weather and well above normal temperatures expected with heat index values over 100F this week.

- 2. Active weather and decreasing temperatures possible this weekend.

DISCUSSION

KEY MESSAGE 1. Generally dry weather and well above normal temperatures expected with heat index values over 100F this week.

A mid to upper level ridge is currently building over the eastern CONUS. Both deterministic and ensemble guidance continue to be in good agreement that this ridge slides over the eastern seaboard through mid to late week. The NAEFS ensemble indicates the 500 mb heights are forecast to be near the climatological max tomorrow into Wednesday before dropping slightly to end the week. With the ridge overhead, generally dry conditions are expected to persist through much of the work week. The bigger story is going to be the heat. Temperatures are forecast to gradually increase each day to the upper 90s for mid to late week. When factoring in humidity, heat index values are likely to exceed 100F, potentially as soon as Tuesday, in the afternoons for the remainder of the week. There is potential we approach Heat Advisory criteria late in the week, but that will largely be dependent on how well the atmosphere mixes out each day.

KEY MESSAGE 2. Active weather and decreasing temperatures possible this weekend.

Global ensembles are in good agreement that the ridge overhead late in the week retrogrades westward, allowing for a trough to slide down the eastern seaboard. As it does, chances for showers and storms are anticipated to increase at the end of the workweek into the weekend. Cooler afternoon highs are forecast for next weekend as well.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

VFR conditions generally expected except possible early morning fog/stratus.

A bit drier air was observed in the low levels through the afternoon as dew points mixed out more today compared to yesterday. While a low level moisture gradient remains in place and there will likely be some degree of low level moisture return, there remains some uncertainty as to the potential for stratus and fog. Think the most likely scenario is restrictions at the typical sites such as OGB/AGS (and briefly AIK) while other sites remain mostly VFR, although brief near sunrise restrictions still remains possible. Guidance continues to limit the potential for widespread IFR restrictions, however, so with the exception of a TEMPO group for OGB/AGS, have left out the mention for IFR restrictions. Cumulus clouds once again tomorrow with little chance for storms and generally light winds.

EXTENDED AVIATION OUTLOOK...Early morning restrictions still possible despite a drier outlook for the week.

CAE WATCHES/WARNINGS/ADVISORIES

SC...None. GA...None.