Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
Issued by NWS Raleigh/Durham, NC
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549 FXUS62 KRAH 100530 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 130 AM EDT Fri May 10 2024 .SYNOPSIS... A cold front will move across the region late Friday, ushering in drier and less humid air for the weekend. && .NEAR TERM /TONIGHT UNTIL 6 AM FRIDAY MORNING/... As of 835 PM Thursday... Mid and high cloudiness continued to exit to the east this evening. This will leave mostly clear to clear skies across the region for the overnight. The latest satellite data indicated a few cirrus upstream over TN, but not much more than that. Lows tonight are expected to be in the upper 50s to mid 60s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... As of 300 PM Thursday... A rather vigorous shortwave trough extending from the eastern Great Lakes southwest to the western OH Valley on Friday morning will quickly advance east and swing across central NC during the afternoon and early evening. A belt of strong mid- level winds of 60+ kts at 500 mb ahead of the trough will lift across VA and NC during the afternoon. At the surface, a cold front will extend from near KORF southwest to near KGSO to west of KCLT during the early afternoon with the front advancing east and southeast as it reaches the coast by midnight. NWP guidance had a notable shift last night slowing the eastward progress of the front and keeping much of central NC in the relatively moist and somewhat unstable area ahead of the front. This trend has slowed but the potential for deeper convection and some severe weather has increased a bit across the Sandhills and Coastal Plain for Friday. Higher res guidance suggests the atmosphere may become weakly unstable for a short period in the eastern Sandhills and southern Coastal Plain in a narrow tongue just ahead of the cold front. Modest mid level lapse rates, the potential for some capping, and perhaps an initial round of light precipitation early in the afternoon just ahead of the most favorable time period could hinder convective development and intensification. If deep convection can develop, it could tap into 0-6km bulk shear values of 35 to 50 kts supporting storm organization and a couple of supercells. Hodographs are long and straight which adds additional concern for large hail. SPC has not surprisingly expanded the marginal risk north and a little west as the guidance has brought the threat area northwestward. Feel the coverage of stronger/deeper storms will still be limited and is more favored to the south and east of the RAH CWA, but would not be surprised if one or two stronger cells develop and move across the Sandhills and southern Coastal Plain with an increased severe weather potential. The window for convection will shut down around dinner time with dry weather expected on Friday night. Further west across the western and northwest Piedmont, the chances for a shower and perhaps a thunderstorm are much more limited and deep convection is not expected. Highs on Friday will range from the upper 70s in the Triad and near the VA border to the lower 80s in most other locations. Noticeably drier air will spread into the region on Friday night with dewpoints falling into the lower 50s with some upper 40s possible across the northern and western Piedmont. Lows will range in the lower top mid 50s. -Blaes && .LONG TERM /SATURDAY THROUGH THURSDAY/... As of 211 PM Thursday... In the wake of the departing upper trough Friday night, NW flow will take hold across the area on Saturday. This will allow for continued dry advection and noticeably cooler temperatures, as highs will only reach the low to mid 70s across the area. A weak shortwave trough is expected to rotate through southern VA/northern NC late in the day Saturday which will bring about a brief increase in cloud cover and perhaps a stray shower or two, but that`s about it. Model guidance has been consistent in showing limited precip across the area thanks in large part to a dry BL featuring dewpoints in the 40s. PoPs in the 15-20 percent range across the northern tier of counties still seems appropriate based on today`s ensemble guidance (but even this may be overdone a bit). Any showers that do manage to make it into the forecast area should dissipate quickly after sunset with dry weather expected Saturday night. Lows will range from the upper 40s to lower 50s. Sunday will see mostly sunny skies and continued cool/dry conditions as weak cyclonic flow aloft gradually flattens out as a ridge builds to our west. Look for another day of below normal highs (mid 70s) with low temps once again falling into the upper 40s to low 50s. No concerns about precip as all forcing will be displaced well to the northeast of the area. The overall pattern next week looks to be active once again. An upper low over the Central Plains will slowly migrate eastward on Monday, inducing downstream ridging across the Southeast states and ultimately resulting in a fairly quiet day across NC with near normal temps and dry weather. This will ultimately change though as the low migrates into the Ohio Valley on Tuesday. Broad/weak forcing for ascent will overspread much of the Southeast on Tuesday coincident with an increase in moisture transport (PW`s will be back above 1.5 inches by Tuesday morning). Showers are expected across the area on Tuesday although just how quickly they arrive is still a little unclear (daybreak Tuesday vs afternoon). Regardless, Tuesday is likely to see widespread cloud cover and rainfall with cooler temps as a result. While thunder seems unlikely at this stage (instability displaced well to the south), precip chances will likely be maximized during the daytime hours with lesser chances Tuesday night into Wednesday morning. Wednesday will see continued precip chances as the upper low opens up and moves through the central Mid Atlantic. As PW`s will remain elevated and the area will be well within the warm sector, instability will be much more readily available on Wednesday ahead of the trough and shower/thunderstorm chances should be a bit higher (60-70 percent range) especially during the afternoon hours. It`s also likely that we`ll have at least some clearing to start the day and temps should make it up into the low/mid 80s prior to the arrival of the trough. Thursday should start off dry in the wake of the departing low, but this looks to be short lived. While shortwave ridging aloft will build in early in the day, this will quickly turn southwesterly as yet another longwave trough sets up across the Central Plains and kicks out a series of embedded shortwaves across the Southeast states through the end of the week. This would favor diurnally driven showers and thunderstorms Thursday afternoon/evening, followed by drying overnight. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... As of 130 AM Friday... TAF period: High confidence in VFR conditions through the next 24 hours. The primary potential for any flight restrictions would come with precipitation moving through FAY during the late morning and afternoon hours. Am not forecasting any widespread ceilings under 10,000 ft. Will maintain the PROB30 for TSRA at FAY as well as adding VCSH for an extended period during the afternoon. Think there could also be some scattered showers at RWI, but confidence is too low to include a mention of precipitation at other sites, although it will remain a possibility. Winds will gust as a cold front moves through, with values up to 20-25 kt as the wind direction shifts from southwest to northwest. Gusts should continue after sunset. Outlook: An isolated shower cannot be ruled out at INT/GSO Saturday afternoon. The next chance of precipitation will come Monday night and Tuesday as low pressure moves into the mid-Atlantic states. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...Blaes LONG TERM...DL AVIATION...Green