11PM Day 1 Convective Outlook for Tuesday, January 6. NO THUNDERSTORM AREAS FORECAST
SUMMARY
Thunderstorm probabilities across the U.S. appear less than 10 percent today through tonight.
Discussion
Thermodynamic profiles across the U.S. remain generally stable, or at least not appreciably conducive to convective development capable of producing lightning, and models indicate little potential for change today through tonight. Limited ongoing moisture return, off a still slowly modifying Gulf boundary-layer, appears likely to become cut off, as low-level flow takes on an increasing westerly component to the south and southwest of a modest cyclone forecast to migrate across the southern Great Lakes region. Increasing large-scale ascent, associated with secondary cyclogenesis near/offshore of the northern Mid Atlantic through southern New England coast by late tonight, may be accompanied by a substantive increase in thunderstorm development, but mostly ahead of the trailing cold front, near/east of the Gulf Stream.
Upstream, models indicate that mid/upper flow will undergo amplification across the northern mid-latitudes of the Pacific into western North America. It appears that this may include at least one vigorous short wave impulse digging toward the Pacific Northwest, accompanied by a potentially notable convective band with embedded thunderstorm activity, but probably not quite reaching the coastal waters prior to 12Z Wednesday.
Farther south, within larger-scale troughing digging across the southern mid- to subtropical latitude eastern Pacific, a relatively compact cyclonic mid-level circulation may evolve, with an associated cold core that could support a developing area of thunderstorm activity. However, before undergoing an east-northeastward acceleration toward northern Baja and the Southwestern international border vicinity, it appears that this will remain offshore through 12Z Wednesday.