textproduct: NWS Wilmington

WHAT HAS CHANGED

No significant changes from the previous forecast with this update.

KEY MESSAGES

1) Warming temperatures, low daytime relative humidity, and zero rain chances through at least Saturday morning will lead to intensifying drought and fire weather concerns through the week.

2) No significant impact on drought conditions expected despite best rain chances/amounts in quite some time this weekend into next week.

DISCUSSION

KEY MESSAGE 1... Warming temperatures, low daytime relative humidity, and zero rain chances through at least Saturday morning will lead to intensifying drought and fire weather concerns through the week.

Weak ridging aloft will support surface high pressure off the Southeast Coast through early Saturday, maintaining dry weather and gradually warming temperatures each day. Strong April sun will mix down dry air from within the subsidence inversion aloft, plunging inland dewpoints down into the 40s today and Friday afternoons with minimum relative humidity expected to bottom out in the 20-25 percent range. West-southwest winds will be fairly mild through Friday, and therefore fire danger statements will likely not be needed.

Above normal 850 mb temps should support high temperatures in the mid to upper 80s through Saturday, with moderate to strong seabreezes keeping coastal highs 5-10 degrees cooler.

Drought continues to worsen across the Carolinas as the last measurable rain occurred two and a half weeks ago on April 5-6. Two-month rainfall totals have only been 30-50 percent of normal, and six month accumulated rainfall is 6 to 10 inches below normal. Increasing plant transpiration as we move deeper into spring is leading to rapid decreases in soil moisture. The USGS Waterlevel Dashboard site shows local river levels have been steadily decreasing since March and about half of our gauges are at their lowest ever recorded stages for this date.

Lastly, HRRR surface smoke fields show that trajectories originating from the large wildfire east of Valdosta, GA will be pointed northward across the eastern Carolinas today. While the sky will likely have a smoky haze to it across our entire area, the SC Dept of Environmental Services is forecasting adverse air quality across Georgetown and Williamsburg counties. An Air Quality Alert is being issued for these two counties through this evening.

KEY MESSAGE 2... No significant impact on drought conditions expected despite best rain chances/amounts in quite some time this weekend into next week.

A frontal system will drag a cold front through Saturday night, with another weak front moving through around Tuesday. These features will keep at least low rain chances in the forecast Saturday afternoon onwards with the best chances Saturday night and Tuesday. The NBM continues to indicate a ~40-50% chance of at least 0.5" for Saturday night/Sunday and a ~20-30% chance for similar amounts Tuesday/Tuesday night. Widespread total amounts of ~0.25-0.5" won't do much to improve the ongoing drought. According to our climate sites, we're 0% of our normal rainfall (~1-1.5") for the past 2 weeks. Embedded thunderstorms are possible with both frontal passages, but severe weather is not expected at this time. The frontal passage on Tuesday appears more favorable for low severe chances, but it is still uncertain at this time.

AVIATION /06Z THURSDAY THROUGH MONDAY/

VFR. West-southwest winds 5-10 kts will prevail through the 6z TAF period, with pinned sea breeze turning winds a bit more southerly along the coast with gusts around 15 kts this afternoon.

Extended Forecast... VFR conditions should prevail through midday Saturday. Showers associated with an approaching cold front could bring MVFR conditions Saturday afternoon through Sunday. Northeasterly wind gusts to 25 knots are possible behind the front Monday.

MARINE

Through Tonight... West-southwest winds 15-20 kts will prevail across the local waters through tonight due to offshore high pressure, with gusts around 25 kts for the 20-60nm offshore waters off the SE NC coast. Seas generally in the 2-4 ft range today and tonight, mix of E swell and SW wind wave.

Friday through Monday... S/SW winds up to 15-20 kt are expected Friday and Saturday ahead of a cold front which drops through the waters late Saturday night. Winds then shift to the NE for Sunday and Monday, with a low chance of SCA conditions Sunday night over coastal waters as sfc high pressure builds to the north and the pressure gradient tightens locally. Gusts over the 20-60 NM waters up to 25-30 kt.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...Air Quality Alert until midnight EDT tonight for SCZ039-055- 056. MARINE...None.