12PM Day 3 Convective Outlook for Friday, January 30. NO THUNDERSTORM AREAS FORECAST
SUMMARY
Thunderstorm probabilities across the U.S. for Friday through Friday night appear less than 10 percent.
Discussion
Models indicate that large-scale mid-level ridging will generally be maintained across the U.S. Pacific coast through Rockies, with short wave ridging also building along the British Columbia coast, in the wake of a short wave trough progressing inland across the Canadian and adjacent northern U.S. Rockies. Precipitation accompanying an associated baroclinic zone may linger into Friday across the Pacific Northwest, with perhaps an upstream warm frontal band also approaching coastal Washington by late Friday night. However, forecast soundings suggest that thermodynamic profiles will not become sufficiently unstable to support an appreciable risk for thunderstorm activity.
Downstream, several short wave perturbations, including one vigorous impulse emerging from the Hudson Bay vicinity, are forecast to consolidate into amplifying, positively tilted large-scale troughing across much of the lower Mississippi Valley and Gulf Basin through southern Atlantic Seaboard by late Friday night. There remains notable spread concerning associated surface cyclogenesis, but it appears that this will remain weak across the eastern Gulf and adjacent Southeast, before undergoing notable strengthening offshore of the southern/mid Atlantic coast after 12Z Saturday. Along and south of a strengthening frontal zone, a deepening moist boundary-layer may become conditionally unstable across parts of the Florida Keys and southeastern Florida Peninsula by Friday. However, forecast soundings indicate that relatively warm and dry air in mid/upper levels will tend to suppress thunderstorm development.