|Dew Point:||52.0°F (11.1°C)|
|Wind:||From the West at 9.0 MPH|
|Sea Level Pressure:||29.77" (1008.2 mb)|
Rain Showers LikelyHigh: 61 Low: 36
SunnyHigh: 57 Low: 35
SunnyHigh: 60 Low: 42
Partly Sunny then Slight Chance Rain ShowersHigh: 57 Low: 41
Chance Rain ShowersHigh: 57 Low: 40
Rain showers likely before 2pm. Mostly sunny, with a high near 61. West wind 8 to 16 mph, with gusts as high as 28 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Mostly clear, with a low around 36. Northwest wind around 17 mph, with gusts as high as 29 mph.
Sunny, with a high near 57. Northwest wind 7 to 15 mph, with gusts as high as 26 mph.
Clear, with a low around 35. West wind 1 to 5 mph.
Sunny, with a high near 60. South wind around 5 mph.
Mostly clear, with a low around 42.
A slight chance of rain showers after 2pm. Partly sunny, with a high near 57.
A chance of rain showers. Mostly cloudy, with a low around 41. Chance of precipitation is 30%.
A chance of rain showers. Partly sunny, with a high near 57. Chance of precipitation is 30%.
... A cold front will move from west to east across the area today, crossing the mountains this morning and then across the piedmont this afternoon. Widespread showers are expected. Thunderstorms are possible for eastern Virginia and North Carolina. High pressure will build in behind the front for tonight and Wednesday, providing several days of fair weather. The next chance of rain is expected for the weekend as Low Pressure develops over the southeastern United States.
NEAR TERM /THROUGH TONIGHT/... As of 947 AM EDT Tuesday...
A cold front will slide east across our area this afternoon into tonight. Scattered showers and a few thunderstorms will develop along the boundary as it progresses east. Some of the storms could be strong to severe in the southeast portion of the forecast area as highlighted in SPC Day 1 convective Outlook. The placement is where there is increasing low level moisture combining with deep layer shear and possibly some heating or richer instability in the warm sector. The main threat will be damaging winds. The NAMnest develops a few strong individual cells before a line forms in eastern Virginia. The latest HRRR forms a line of storms around 18z and moves it east this afternoon. Decided to expand our chances of thunderstorms further north and increase in coverage for this afternoon. Adjusted late morning temperatures into this afternoon utilizing the current surface obs, their trends and a blend of Conshort and NBM. Elected to adjusted QPF up a little for this afternoon. Also slowed the exit of the rain this afternoon. More adjustments later this morning...
As of 400 AM EDT Tuesday...
Passage of a cold front will bring widespread showers today. Main focus for these showers will be across the mountains this morning, then across the piedmont this afternoon...rainfall amounts averaging about a half inch /0.50/. Potential for strong to severe thunderstorms will exist across eastern North Carolina into southeastern Virgina.
A deep upper trough covering much of the central/eastern CONUS is expected to progress slowly eastward today. While the primary occluding cyclone is expected to move from the Upper Great Lakes into Ontario, a secondary frontal wave is expected to move from Upstate SC this morning into the eastern mid Atlantic this evening and southern New England overnight. As this occurs, relatively rich low-level moisture is expected to stream northward over portions of the central/eastern Carolinas into the Tidewater region in advance of the eastward-moving cold front.
Most of our forecast area will escape the severe thunderstorm threat. There is a marginal risk for the Danville area, but timing of the front suggest it will have cleared areas west of Highway 29 by the time the deeper convection has a chance to develop. That said, if storms do manage to develop before exiting the CWA, the main threat would be from damaging wind gusts.
Ahead of the front winds were out of the southeast. This upslope component to the wind was resulting in a persistent layer of stratus and fog up against the Blue Ridge. This fog may restrict visibility attms to less than a mile, and potentially as low as a quarter mile where the cloud base intersects the terrain (e.g. the Blue Ridge Parkway). Once the front passes, expect rapid improvement.
Model timing of the front, brings it through the mountains this morning, greatest rain threat west of the Blue Ridge before noon, followed by clearing during the afternoon. For areas east of the Blue Ridge, expect the rain to linger longer, with the clearing delayed until evening. All areas should be clear by tonight with a much drier airmass advecting into the region from the west.
Temperatures today will remain mild with highs in the 60s, and possibly into the lower 70s. There may actually be a brief spike in the temperature with the actual frontal passage, the clouds ahead of the front holding the temperature down until clearing can materialize with the frontal mixing. Any clearing prior to the arrival of the post frontal cold air advection will contribute to solar insolation and an uptick in temperature. Once the sun sets, the cold air advection, in addition to a rapid drop in dewpoints, will allow for the temperature to quickly drop after sunset. Lows tonight should be closer to normal with lows ranging from the 30s in the mountains to the 40s in the piedmont.
SHORT TERM /WEDNESDAY THROUGH FRIDAY/... As of 330 AM EDT Tuesday...
High pressure will build over the Mid Atlantic on Wednesday and persist through Thursday. Confidence is excellent that it should remain dry during both days thanks to good agreement in the models. While calm winds and mainly clear skies should allow good radiational cooling during Wednesday night, low temperatures by Thursday morning do not seem to quite get close enough to freezing. Thus, it seems only patchy frost may be the main issue along and west of the Blue Ridge. With the mountains having its second chance in less than a week to get near freezing and/or have frost occuring, the 2019 growing season will more than likely be pronounced done afterward as it is getting so late in the year.
Details significantly diverge in the models by Thursday night and Friday. The latest GFS shows a fast and progressive pattern with an approaching upper level trough in the form of an open wave crossing the Plains and pushing a cold front over the Appalachian Mountains by late Friday. That scenario would result in moisture streaming from the Gulf to provide rainfall south of Route 460. Conversely, the latest ECMWF, Canadian, and other international models are slower with this upper level trough as they cut it off over New Mexico. This scenario would result in a cold front only reaching the southern Mississippi Valley by Friday and keeping high pressure over the Mid Atlantic. Because the GFS has been trending slower and slower with this cold front during the past several days, this forecast has been steered toward the drier and slower solution from the global model consensus. Consequently, PoPs were lowered, sky cover was decreased, and high temperatures were raised for Friday.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... As of 210 PM EDT Monday...
An active weather pattern is expected during the long term period. Pattern evolution uncertainty result in low forecast confidence in details of the forecast. The uncertainties stem from when the upper trough approaches from the west, which will depend on whether or not it remains attached to the larger scale westerly flow or developed a cutoff low in the base of the trough.
On the ECMWF(similar on UKMET and CMC), the low becomes cutoff over Texas and Oklahoma around Saturday and lifts northeast into early next week, while the GFS holds an open trough that progresses east. The new WPC prognostic charts showed a less prominent frontal wave moving across the Southeast during the weekend compared with previous progs. Utilized a blend of Hpcguide and NBM to capture a progressive solution.
A cold front will move southeast across the region Friday and be located to our south Friday night. A wave of low pressure will develop along the boundary around Friday night and ride along the boundary Saturday into Saturday night. A weak shortwave will rotate east across the region Sunday morning. High pressure will build across the region on Sunday afternoon into Sunday night. A cold front will approach from the west on Monday. Details on the long range will become clearer over time.